Image processing apparatus, image processing method, and printing apparatus and printing system using the image processing apparatus Number:7,385,730 from the United States Patent and Trademark Office (PTO) owispatent In an apparatus for performing printing using a color ink-jet head having a plurality of ink-discharge-port strings corresponding to ink materials having different color tones, a high-quality image having excellent gradation can be recorded, while reducing the cost of the apparatus and increasing the data processing speed by reducing the capacity of a memory for storing dot arrangement patterns. For that purpose, as a plurality of dot arrangement patterns for determining dot arrangement at output within a M.times.N-dot region for one input pixel, (1) patterns having a large number of gradation levels that can be represented (for example, nine gradation levels) and a high recording resolution (for example, 1,200 dpi (dots per inch).times.2,400 dpi) are used for colors in which uneven stripes tend to be pronouncedly observed (for example, light cyan and light magenta), and (2) patterns having a small number of gradation levels that can be represented (for example, five gradation levels) and a low recording resolution (for example, 1,200 dpi.times.1,200 dpi) are used for colors in which uneven stripes tend to be less pronouncedly observed (for example, black, cyan, magenta and yellow).<H processing, apparatus, Image, processin, 7385730.html, Patent, pto, 7385730

Title: Image processing apparatus, image processing method, and printing apparatus and printing system using the image processing apparatus

Abstract: In an apparatus for performing printing using a color ink-jet head having a plurality of ink-discharge-port strings corresponding to ink materials having different color tones, a high-quality image having excellent gradation can be recorded, while reducing the cost of the apparatus and increasing the data processing speed by reducing the capacity of a memory for storing dot arrangement patterns. For that purpose, as a plurality of dot arrangement patterns for determining dot arrangement at output within a M.times.N-dot region for one input pixel, (1) patterns having a large number of gradation levels that can be represented (for example, nine gradation levels) and a high recording resolution (for example, 1,200 dpi (dots per inch).times.2,400 dpi) are used for colors in which uneven stripes tend to be pronouncedly observed (for example, light cyan and light magenta), and (2) patterns having a small number of gradation levels that can be represented (for example, five gradation levels) and a low recording resolution (for example, 1,200 dpi.times.1,200 dpi) are used for colors in which uneven stripes tend to be less pronouncedly observed (for example, black, cyan, magenta and yellow).

Patent Number: 7,385,730 Issued on 06/10/2008 to Ogasahara, et al.

Inventors: Ogasahara; Takayuki (Rochester, NY), Tajika; Hiroshi (Kanagawa, JP), Konno; Yuji (Kanagawa, JP), Kawatoko; Norihiro (Kanagawa, JP), Edamura; Tetsuya (Kanagawa, JP), Maeda; Tetsuhiro (Kawasaki, JP), Masuyama; Atsuhiko (Kanagawa, JP)
Assignee: Canon Kabushiki Kaisha (Tokyo, JP)

Appl. No.: 10/198,108

Filed: July 19, 2002

Foreign Application Priority Data


Jul 31, 2001 [JP]			2001-232920

Current U.S. Class: 358/3.01 ; 358/1.8; 358/1.9; 358/2.1; 358/3.02; 358/3.06; 358/3.09; 358/3.1; 358/3.11; 358/3.14; 358/3.23; 358/502; 358/518; 358/520; 358/534; 382/112; 382/167; 382/270

Field of Search: 358/1.9,1.8,1.1,5,461,517,354,1.16,404,504,3.01,3.02,3.06,3.09,3.1,3.23,3.13-3.18,534-536,2.1,3.11,502,518,519 347/119,129,43,55,20 345/590 430/359 400/323,124 101/93.04,93 382/112,270,167

References Cited [Referenced By]

U.S. Patent Documents


4884080	November 1989	Hirahara et al.
5729358	March 1998	Uchiyama et al.
6024438	February 2000	Koike et al.
6163384	December 2000	Kato
6215424	April 2001	Cooper
6336706	January 2002	Otsuki
6439683	August 2002	Matsumoto et al.
6693727	February 2004	Kanno et al.
7057756	June 2006	Ogasahara et al.
2001/0026723	October 2001	Otsuka et al.
2002/0021319	February 2002	Kawatoko et al.
2002/0067519	June 2002	Suzuki et al.

Foreign Patent Documents


1 079 327	Feb., 2001	EP
2000-216687	Aug., 2000	JP
2000-216694	Aug., 2000	JP
2001-63016	Mar., 2001	JP
2002-29097	Jan., 2002	JP

Primary Examiner: Poon; King Y.
Assistant Examiner: Kau; S.
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper & Scinto

Claims

What is claimed is:

1. An image processing apparatus that performs image processing to print an image on a print medium using a print head capable of printing dots of a plurality of types of print materials, including deep-color print materials and light-color print materials, said apparatus comprising: storage means for storing dot patterns, including a first set of dot patterns corresponding to a first deep-color print material, a second set of dot patterns corresponding to a second deep-color print material, a third set of dot patterns corresponding to a first light-color print material, and a fourth set of dot patterns corresponding to a second light-color print material, wherein each dot pattern corresponding to the first and second deep-color print material is associated with one of a first number of gradation levels, and a position of a pixel of the image, and each dot pattern corresponding to the first and second light-color print materials is associated with one of a second number of gradation levels greater than the first number and the position of the pixel; and selecting means for selecting a dot pattern from the dot patterns stored in said storage means, based on a corresponding gradation level and position of the pixel, wherein the first light-color print material has a same color as the first deep-color print material and has lower density than that of the first deep-color print material, and the second light-color print material has a same color as the second deep-color print material and has a lower density than that of the second deep-color print material, wherein the dot pattern corresponding to the first deep-color print material is different from the dot pattern corresponding to the second deep-color print material at the same gradation level and the same pixel position, and the dot pattern corresponding to the first light-color print material is different from the dot pattern corresponding to the second light-color print material at the same gradation level and the same pixel position, and wherein a print resolution of the dot patterns corresponding to the first and second deep-color print materials is lower than a print resolution of the dot patterns corresponding to the first and second light-color print materials.

2. An image processing apparatus according to claim 1, wherein, when the print resolution of the dot patterns corresponding to the first and second deep-color print materials is represented by X, and the print resolution of the dot patterns corresponding to the first and second light-color print materials is represented by Y, the following condition is satisfied: 1/Y=N/X, where N is an integer.

3. A print apparatus that prints an image on a print medium using a print head, said apparatus comprising: an image processing apparatus according to claim 1.

4. A print system comprising: a print apparatus including an image processing apparatus according to claim 1; and a host apparatus for supplying the print apparatus with data of the pixel having the gradation level.

5. The image processing apparatus according to claim 1, wherein the first deep-color print material is a cyan ink and the first light print material is a light cyan ink, and the second deep-color print material is a magenta ink and the second light print material is a light magenta ink.

6. The image processing apparatus according to claim 1, wherein the plurality of types of print materials include a third print material different from the first and second deep-color print materials and the first and second light-color print materials, and wherein dot patterns corresponding to the third print material are the same as the dot patterns corresponding to one of the first and second deep-color print materials.

7. An image processing method of performing image processing to print an image on a print medium using a print head capable of printing dots of a plurality of types of print materials, including deep-color print materials and light-color print materials, said method comprising: a selecting step of selecting a dot pattern from a storage means for storing dot patterns, including a first set of dot patterns corresponding to a first deep-color print material, a second set of dot patterns corresponding to a second deep-color print material, a third set of dot patterns corresponding to a first light-color print material, and a fourth set of dot patterns corresponding to a second light-color print material, wherein each dot pattern corresponding to the first and second deep-color print material is associated with one of a first number of gradation levels, and a position of a pixel of the image, and each dot pattern corresponding to the first and second light-color print materials is associated with one of a second number of gradation levels greater than the first number and the position of the pixel, wherein the selection is based on a corresponding gradation level and position of the pixel, wherein the first light-color print material has a same color as the first deep-color print material and has lower density than that of the first deep-color print material, and the second light-color print material has a same color as the second deep-color print material and has a lower density than that of the second deep-color print material, wherein the dot pattern corresponding to the first deep-color print material is different from the dot pattern corresponding to the second deep-color print material at the same gradation level and the same pixel position, and the dot pattern corresponding to the first light-color print material is different from the dot pattern corresponding to the second light-color print material at the same gradation level and the same pixel position, and wherein a print resolution of the dot patterns corresponding to the first and second deep-color print materials is lower than a print resolution of the dot patterns corresponding to the first and second light-color print materials.

8. A computer readable storage medium storing a control program for causing a computer to execute an image processing method according to claim 7.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image processing apparatus and an image processing method, and a printing apparatus and a printing system using the image processing apparatus. More particularly, the invention is suitably applied to a printing apparatus for printing a color image using a plurality of types of printing materials having different color tones, and an image processing method for the printing apparatus. The present invention may be applied not only to an ordinary printing apparatus, but also to any other appropriate apparatus, such as a copier, a facsimile apparatus having a communication system, a word processor having a printing unit, or the like, or to an industrial recording apparatus combined with various types of processing apparatuses.

2. Description of the Related Art

A printer is known as a printing apparatus for recording information, including desired characters, images or the like, on a sheet-shaped printing medium, such as paper, a film or the like, that serves as an information output apparatus for a word processor, a personal computer, a facsimile apparatus or the like.

Various types of conventional printing methods by a printer are known. Recently, ink-jet printing has become important because it has various advantages over other printing methods, such as, for example, the capability to perform non-contact printing on a printing medium, such as paper or the like, to easily form a color image, and to perform silent printing. A so-called serial method, in which printing is performed by mounting an ink-discharging print head in accordance with desired print information and scanning a printing medium, such as paper or the like, with the print head in a direction (a main scanning direction) orthogonal to a conveying direction (a sub-scanning direction) of the print medium, has been widely utilized as the configuration of a printing scanning system of the printing apparatus to which the ink-jet method is applied, because an inexpensive and small apparatus can be easily obtained.

In conventional ink-jet printing apparatuses, dots are recorded according to binary-encoding processing or multivalue-encoding processing.

Recently, as a result of increasing popularity and availability of digital cameras having pixels exceeding three million in number, and realization of high picture quality in image input apparatuses, such as high-resolution scanners and the like, the amount of data to be processed by an output apparatus is increasing, and high accuracy in printing is required for a high-resolution image.

FIG. 26 is a graph illustrating the human visual characteristic (a VTF curve) with respect to gradations. The human visual characteristic indicates the number of gradations that can be discriminated by a human being at a certain observation distance (25 cm). If the capability to reproduce gradations of a printing apparatus is superior to the human visual characteristic, it can be said that the printing apparatus has an excellent gradation reproducing capability.

As is apparent from FIG. 26, when comparing the gradation reproducing capability of a printer performing encoding processing to various values of the human visual characteristic, the range exceeding the human visual characteristic easily widens as the number of encoding values increases. For example, in order to provide a gradation reproducing capability equivalent to multivalue encoding (septenary encoding) for input data having a resolution of 600 ppi (pixels per inch, reference value), binary encoding is necessary for input data with a resolution of 1,500 ppi. Accordingly, the gradation reproducing capability can be easily widened by performing multivalue(septenary)-encoding processing for input data having a resolution of 600 ppi than by performing binary encoding processing.

Multivalue-encoding processing will be briefly described with reference to FIGS. 27A and 27B. If it is assumed that a printing apparatus has an output resolution of 1,200.times.1,200 dpi (dots per inch, reference value) in the main scanning direction and in the sub-scanning direction, in binary-encoding processing shown in FIG. 27A, an input resolution of 1,200 ppi is required, and two gradations are represented by presence/absence of formation of one dot for an input pixel having a size of about 21.17 .mu.m ( 1/1,200 inch) square. On the other hand, in quinary-encoding processing shown in FIG. 27B, five gradations are represented by presence/absence of formation of 2.times.2 =4 dots for an input pixel having a size of about 42.33 .mu.m ( 1/600 inch) square. Accordingly, when performing quinary-encoding processing, input data can be reduced to 1/4 of that when performing binary-encoding processing. That is, for a request for a print having high picture quality, while a high input resolution is necessary and the amount of data increases in binary-encoding processing, a relatively low input resolution is necessary and the amount of data decreases as the number of encoding values increases.

Unevenness sometimes results, for example, when moving a print head in the main scanning direction, due to errors in production of a scanning system of a printer main body, and the like (hereinafter termed "main-body noise"). Furthermore, when providing two discharging-port columns for discharging ink in the main scanning direction by being shifted by 1/2 of the pitch of arrangement of discharging ports in the sub-scanning direction (the sheet feeding direction), causing discharging ports of respective columns to perform recording of even-numbered rasters and odd-numbered rasters, deviation (in even/odd registration) in the position of ink provision (the dot forming position) is sometimes produced between even-numbered rasters and odd-numbered rasters.

A printing apparatus performing binary processing tends to be influenced by such main-body noise and head noise. In a printer performing multivalue processing, however, as disclosed, for example, in Japanese Patent Application Laid-Open (Kokai) No. 2001-63016 (2001), by indexing a plurality of patterns, each for determining a dot arrangement at output within a M.times.N-dot region for one input pixel, and selecting an appropriate pattern, the influence of main-body noise and head noise can be reduced.

Because of the above-described reasons, in recent ink-jet printing apparatuses, multivalue processing using a dot-pattern index (hereinafter termed "index processing") tends to be used instead of binary processing.

As described above, multivalue processing has advantages such as, for example, only a relatively low input resolution is required and the amount of data can be reduced, and the influence of main-body noise and head noise can also be reduced, compared with binary processing.

However, it is necessary to provide dot patterns, whose number equals the number of recording gradations, each of which determines dot arrangement in accordance with the number of recording gradations in a predetermined region. Furthermore, in order to mitigate the influence of main-body noise and head noise, it is necessary to provide a plurality of dot arrangement patterns in a predetermined region even at the same gradation. Still further, if the number of recording gradations is increased in order to improve the image quality, it is also necessary to increase the capacity of a memory for storing a table of patterns.

Recently, the use of a printer which provides not only a black or another monochrome print, but also a color print or a high-quality print using photo-ink materials (comprising four primary color ink materials and light-color ink materials of predetermined colors) has been generalized. In accordance with an increase in the types of ink materials, it is necessary to provide a dot-pattern table for each color tone, and a large-capacity memory (a ROM (read-only memory) or the like) for storing such tables, resulting in an increase in the cost of a printing apparatus. If the size of a dot-pattern table is simply reduced, banding unevenness between main scanning lines of the print head tends to be pronounced, thereby causing the possibility of a decrease in the image quality.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of the above-described problems. It is an object of the present invention to provide a printing apparatus and an image processing method in which a high-quality image can be formed while reducing the capacity of a memory for storing dot-arrangement patterns.

In one aspect of the present invention, an image processing apparatus that processes image data applied in a printing apparatus that forms images on a print medium using a plurality of print heads that form dots in different conditions, the apparatus includes processing means for performing, on pixel data of an image to be printed, multivalue processing which represents at least two types of gradation representations in accordance with the different conditions, the at least two types of gradation representations having a different number of gradation levels and storage means for storing each dot pattern used for multivalue processing which represents a corresponding gradation level, for at least each of the at least two types of gradation representations, wherein recording resolutions differ between dot patterns representing one of the at least two gradation representations having one number of gradation levels and dot patterns for representing another gradation representation having another number of gradation levels.

In another aspect of the present invention, a print apparatus that forms images on a print medium using a plurality of print heads that form dots in different conditions, the apparatus includes an image processing apparatus that processes image data applied in a print apparatus that forms images on a print medium using a plurality of print heads that form dots in different conditions, includes (i) processing means for performing, on pixel data of an image to be printed, multivalue processing which represents at least two types of gradation representations in accordance with the different conditions, the at least two types of gradation representations having a different number of gradation levels and (ii) storage means for storing each dot pattern used for multivalue processing which represents a corresponding gradation level, for at least each of the at least two types of gradation representations and image formation control means for performing image formation based on dot patterns obtained by the multivalue processing performed by the image processing apparatus, wherein recording resolutions differ between dot patterns representing one of the at least two gradation representations having one number of gradation levels and dot patterns for representing another gradation representation having another number of gradation levels.

In still another aspect of the present invention, an image processing method of processing image data, applied to a print apparatus that forms images on a print medium using a plurality of print heads that form dots in different conditions, includes a processing step of (i) performing, on pixel data of an image to be printed, multivalue processing which represents at least two types of gradation representations in accordance with the different conditions, the at least two types of gradation representations having a different number of gradation levels, and (ii) selecting a dot pattern from storage means for storing each dot pattern used for multivalue processing which represents a corresponding gradation level, for each of the at least two gradation representations, wherein recording resolutions differ between dot patterns representing one of the at least two gradation representations having one number of gradation levels and dot patterns for representing another gradation representation having another number of gradation levels.

In yet another aspect of the present invention, a print method that forms images on a print medium using a plurality of print heads that form dots in different conditions, includes an image processing step (i) performing, on pixel data of an image to be printed, multivalue processing which represents at least two types of gradation representations in accordance with the different conditions, the at least two types of gradation representations having a different number of gradation levels, and (ii) selecting a dot pattern from storage means for storing each dot pattern used for multivalue processing which represents a corresponding gradation level, for each of the at least two gradation representations and an image formation step of performing image formation based on dot patterns obtained in the image processing step, wherein recording resolutions differ between dot patterns representing one of the at least two gradation representations having one number of gradation levels and dot patterns for representing another gradation representation having another number of gradation levels.

In still another aspect of the present invention, a print system includes a print apparatus that forms images on a print medium using a plurality of print heads that form dots in different conditions, the apparatus comprising an image processing apparatus that processes image data applied in a print apparatus that forms images on a print medium using a plurality of print heads that form dots in different conditions, the apparatus comprising (i) processing means for performing, on pixel data of an image to be printed, multivalue processing which represents at least two types of gradation representations in accordance with the different conditions, the at least two types of gradation representations having a different number of gradation levels and (ii) storage means for storing each dot pattern used for multivalue processing which represents a corresponding gradation level, for at least each of the at least two types of gradation representations, image formation control means for performing image formation based on dot patterns obtained by the multivalue processing performed by the image processing apparatus and a host apparatus for supplying the print apparatus with image data, wherein recording resolutions differ between dot patterns representing one of the at least two gradation representations having one number of gradation levels and dot patterns for representing another gradation representation having another number of gradation levels.

In still another aspect of the present invention, a storage medium storing a control program for causing a computer to execute an image processing method is disclosed, the method including a processing step of (i) performing, on pixel data of an image to be printed, multivalue processing which represents at least two types of gradation representations in accordance with the different conditions, the at least two types of gradation representations having a different number of gradation levels, and (ii) selecting a dot pattern from storage means for storing each dot pattern used for multivalue processing which represents a corresponding gradation level, for each of the at least two gradation representations, wherein recording resolutions differ between dot patterns representing one of the at least two gradation representations having one number of gradation levels and dot patterns for representing another gradation representation having another number of gradation levels.

In still another aspect of the present invention, a storage medium storing a control program for causing a print apparatus to execute a print method is disclosed, the method including an image processing step (i) performing, on pixel data of an image to be printed, multivalue processing which represents at least two types of gradation representations in accordance with the different conditions, the at least two types of gradation representations having a different number of gradation levels, and (ii) selecting a dot pattern from storage means for storing each dot pattern used for multivalue processing which represents a corresponding gradation level, for each of the at least two gradation representations and an image formation step of performing image formation based on dot patterns obtained in the image processing step, wherein recording resolutions differ between dot patterns representing one of the at least two gradation representations having one number of gradation levels and dot patterns for representing another gradation representation having another number of gradation levels.

In still another aspect of the present invention, a control program for causing a computer to execute an image processing method is disclosed, the method including a processing step of (i) performing, on pixel data of an image to be printed, multivalue processing which represents at least two types of gradation representations in accordance with the different conditions, the at least two types of gradation representations having a different number of gradation levels, and (ii) selecting a dot pattern from storage means for storing each dot pattern used for multivalue processing which represents a corresponding gradation level, for each of the at least two gradation representations, wherein recording resolutions differ between dot patterns representing one of the at least two gradation representations having one number of gradation levels and dot patterns for representing another gradation representation having another number of gradation levels.

In still another aspect of the present invention, a control program for causing a print apparatus to execute a print method is disclosed, the method including an image processing step (i) performing, on pixel data of an image to be printed, multivalue processing which represents at least two types of gradation representations in accordance with the different conditions, the at least two types of gradation representations having a different number of gradation levels, and (ii) selecting a dot pattern from storage means for storing each dot pattern used for multivalue processing which represents a corresponding gradation level, for each of the at least two gradation representations and an image formation step of performing image formation based on dot patterns obtained in the image processing step, wherein recording resolutions differ between dot patterns representing one of the at least two gradation representations having one number of gradation levels and dot patterns for representing another gradation representation having another number of gradation levels.

As described above, according to the present invention, for example, when performing color recording using recording materials having a plurality of color tones, by utilizing the fact that unevenness among stripes tends to be easily observed and hardly observed depending on colors in the human visual characteristic, high-resolution recording (using large-size dot patterns) and low-resolution recording (using small-size dot patterns) are performed for colors of the former case and for colors of the latter case, respectively. As a result, it is possible to reduce the capacity of a pattern table, increase the data processing speed and reduce the cost of the apparatus, while maintaining the same image quality as when using large-size dot patterns for all color tones.

The foregoing and other objects, advantages and features of the present invention will become more apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an external appearance and the configuration of an ink-jet printer according to a first embodiment of the present invention;

FIG. 2 is a perspective view illustrating a state in which outer members are removed from the ink-jet printer shown in FIG. 1;

FIG. 3 is a perspective view illustrating a state in which a recording-head cartridge to be used in the first embodiment is assembled;

FIG. 4 shows exploded perspective views illustrating the recording-head cartridge shown in FIG. 3;

FIG. 5 shows exploded perspective views illustrating a recording head shown in FIG. 4, as seen from an oblique lower portion;

FIGS. 6A and 6B are perspective views illustrating a scanner cartridge in the first embodiment;

FIG. 7 is a schematic block diagram illustrating the entire configuration of electric circuitry in the first embodiment;

FIG. 8 is a block diagram illustrating the internal configuration of a main PCB (printed circuit board) shown in FIG. 7;

FIG. 9 is a block diagram illustrating the internal configuration of an ASIC (application specific integrated circuit) shown in FIG. 8;

FIG. 10 is flowchart illustrating operations in the first embodiment;

FIG. 11 is a diagram illustrating arrangement of nozzles of the recording head in the first embodiment;

FIG. 12 is a graph illustrating changes in the density (OD (optical density) value) with respect to the amount of ink provision, for deep ink and light ink;

FIGS. 13A-13C are diagrams illustrating dot arrangements for basic patterns for index processing for deep color ink and light color ink, in the first embodiment;

FIGS. 14A and 14B are diagrams illustrating index processing in the first embodiment; FIG. 14A illustrates patterns for five-value index processing for deep color ink; and FIG. 14B illustrates patterns for nine-value index processing for light color ink;

FIGS. 15A-15E are diagrams illustrating processing when heads having different dot diameters are used, in a second embodiment of the present invention;

FIG. 16 is a schematic block diagram illustrating an image processing system of an ink-jet printer according to the second embodiment;

FIG. 17 is a block diagram illustrating a more detailed configuration of an image processing unit shown in FIG. 16;

FIG. 18 is a block diagram illustrating a more detailed configuration of a dot pattern address generation unit shown in FIG. 17;

FIG. 19 is a block diagram illustrating a more detailed configuration of a dot pattern table storage unit shown in FIG. 17;

FIG. 20 is a diagram illustrating patterns for index processing according to a third embodiment of the present invention;

FIGS. 21A and 20B are diagrams illustrating recording resolutions for deep color ink and light color ink, respectively, in the third embodiment;

FIG. 22 is a block diagram illustrating a configuration of a mask-pattern-table storage unit used in an image processing system in the third embodiment;

FIGS. 23A and 23B are diagrams illustrating the details of mask patterns used in the third embodiment;

FIG. 24 is a diagram illustrating a pattern for index processing according to a fourth embodiment of the present invention;

FIG. 25 is a diagram illustrating an example of concept in which a program for executing a method according to the present invention and related data are supplied from a storage medium to an apparatus;

FIG. 26 is a graph illustrating the human visual characteristic (VTF curve) with respect to gradation levels; and

FIGS. 27A and 27B are diagrams illustrating binary processing and multivalue processing, respectively, for input image data.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A recording apparatus according to a preferred embodiment of the present invention will now be described with reference to the drawings.

In the following embodiment, a description will be provided illustrating a printer as a recording apparatus using an ink-jet recording method.

In the description that follows, the word "print" (also termed "recording") indicates both a case in which information including characters, figures or the like is formed, and a case in which an image, a figure, a pattern or the like is formed on a print medium, or the medium is processed, irrespective of whether a human being is capable of sensing the information or not.

In the description that follows, the word "print medium" or "recording sheet" indicates both paper used in a conventional print apparatus, and a substance that can receive ink, such as cloth, a plastic film, a metal plate, glass, ceramics, wood, leather or the like. In the following description, however, a print medium is also sometimes called a "recording medium" or simply "paper".

In the description that follows, the word "ink" (sometimes also termed a "liquid") is to be interpreted in context with the above-described definition of "print", and indicates a liquid that can be used for forming an image, a figure, a pattern or the like, processing a print medium, or processing ink (for example, solidification or provision of insolubility of a color material within ink supplied to a print medium).

1. Apparatus Main Body

FIGS. 1 and 2 illustrate the schematic configuration of a printer using an ink-jet recording method according to a first embodiment of the present invention. In FIG. 1, an outer hull of a main body M1000 of the printer includes outer members comprising a lower case M1001, an upper case M1002, an access cover M1003, a discharge tray M1004, and a chassis M3019 (shown in FIG. 2) accommodated within the outer members.

The chassis M3019 is made of a plurality of plate-shaped metal members having predetermined rigidity, serves as a skeleton of the recording apparatus, and holds respective recording operation mechanisms (to be described later).

The lower case M1001 and the upper case M1002 constitute a substantially lower half portion and a substantially upper half portion, respectively of the outer hull of the apparatus main body M1000, and a hollow structure having an accommodating space for accommodating the respective mechanisms is provided by combining the two cases. An opening is formed in each of an upper portion and a front portion of the apparatus main body M1000.

One end portion of the discharge tray M1004 is rotatably held on the lower case M1001. By rotation of the discharge tray M1004, the size of the opening formed in the front portion of the lower case M1001 can be increased/decreased. Accordingly, when executing a recording operation, by increasing the opening by rotating the discharge tray M1004 toward the front side, a recording sheet can be discharged from the opening, and discharged recording sheets can be sequentially accumulated on the discharge tray M1004. Two auxiliary trays M1004a and M1004b are accommodated within the discharge tray M1004. By drawing each tray toward the front side whenever necessary, the supporting area for the sheets can be enlarged/reduced in three stages.

One end portion of the access cover M1003 is rotatably held on the upper case M1002, and an opening formed in the upper surface of the upper case M1002 can be increased/decreased. By opening the access cover M1003, a recording head cartridge H1000, an ink tank H1900 or the like (shown in FIG. 3) accommodated within the apparatus main body M1000 can be exchanged. Although not illustrated in FIGS. 1 and 2, by opening/closing the access cover M1003, a projection formed at the inner surface of the access cover M1003 rotates a cover opening/closing lever. By detecting the position of rotation of the lever by a microswitch or the like, the opened/closed state of the access cover M1003 can be detected.

On a rear upper surface of the upper case M1002, there are provided a depressable power supply key E0018 and a depressable resumption key E0019, as well as an LED (light-emitting diode) E0020. By depressing the power-supply key E0018, the LED E0020 is lit to notify the operator that recording can be performed. The LED E0020 has various display functions, such as changing a flashing pattern, or the color, notifying the operator of a trouble in the printer, and the like. It is also possible to ring a buzzer E0021 (shown in FIGS. 7 and 8). Further, a print operation can be paused when trouble arises and, when a trouble or the like has been solved, recording is resumed by depressing the resumption key E0019.

2. Recording Operation Mechanism

Next, a recording mechanism accommodated and held in the apparatus main body M1000 of the printer, according to the first embodiment will be described.

Referring now to FIG. 2, the recording operation mechanism in the first embodiment includes an automatic feeding unit M3022 for automatically feeding individual recording sheets into the apparatus main body M1000, a conveying unit M3029 for guiding the recording sheet individually fed from the automatic feeding unit M3022 to a predetermined recording position, and further guiding the recording sheet from the recording position to a discharge unit M3030, a recording unit for performing desired recording on the recording sheet conveyed to the recording position, and a recovery unit M5000 for performing recovery processing for the recording unit or the like.

The recording unit includes a carriage M4001 movably supported on a carriage shaft M4021, and a recording head cartridge H1000 (not shown) detachably mounted on the carriage M4001.

2.1 Recording Head Cartridge

First, the recording head cartridge H1001 used in the recording unit will be described with reference to FIGS. 3-5.

The recording head cartridge H1000 includes, as shown in FIG. 3, an ink tank H1900 for storing ink, and a recording head H1001 for discharging ink supplied from the ink tank H1900 from nozzles in accordance with recording information. A so-called cartridge type head that is detachably mounted in the carriage M4001 (to be described later) is adopted as the recording head H1001.

In the recording head cartridge H1000, in order to allow photographic high-picture-quality color recording, the independent ink tanks H1900 for respective colors, such as black, light cyan, light magenta, cyan, magenta and yellow, are provided. As shown in FIG. 4, each of the ink tanks H1900 is detachably mountable in the recording head H1001.

As shown in the exploded perspective view of FIG. 5, the recording head H1001 includes a recording element substrate H1100, a first plate H1200, an electric wire substrate H1300, a second plate H1400, a tank holder H1500, a liquid channel forming member H1600, filters H1700 and a seal rubber H1800.

On the recording element substrate H1100, a plurality of recording elements for discharging ink, and electric wires, made of Al or the like, for supplying each recording element with electric power are formed according to a film forming technique, a plurality of ink channels, and a plurality of discharge ports H1100T corresponding to the recording elements are formed according to photolithography on one surface of a Si substrate, and an ink supply port for supplying the plurality of ink channels with ink is opened at the back of the Si substrate. The recording element substrate H1100 is bonded and fixed on the first plate H1200, where ink supply ports H1201 for supplying the recording element substrate H1100 with ink are formed. Furthermore, the second plate H1400 has an opening and is bonded and fixed on the first plate H1200. The electric wire substrate H1300 is held so as to be electrically connected to the recording element substrate H1100 via the second plate H1400. The electric wire substrate H1300 applies an electric signal for discharging ink to the recording element substrate H1100, and includes electric wires corresponding to the recording element substrate H1100, and an external signal input terminal H1301, provided at an end portion of the electric wires, for receiving an electric signal from the apparatus main body M1000. The external-signal input terminal H1301 is positioned and fixed on the back of the tank holder H1500 (to be described later).

On the tank holder H1500 for detachably holding the ink tank H1900, the liquid-channel forming member H1600 is fixed, for example, according to ultrasonic welding, to form an ink channel H1501 from the ink tank H1900 to the first plate H1200. The filters H1700 are provided at end portions near the ink tank H1900 of the ink channel H1501 engaged with the ink tank H1900, in order to prevent penetration of dust from the outside. The seal rubber H1800 is mounted at a portion engaged with the ink tank H1900, in order to prevent evaporation of ink from the engaged portion.

The recording head H1001 is obtained by combining a tank holder unit including the tank holder H1500, the liquid channel forming member H1600, the filters H1700 and the seal rubber H1800 in the above-described manner, and a recording-element unit including the recording-element substrate H1100, the first plate H1200, the electric-wire substrate H1300 and the second plate H1400, by means of bonding or the like.

2.2 Carriage

Next, The carriage M4001 mounting the recording head cartridge H1000 will be described with reference to FIG. 2.

As shown in FIG. 2, on the carriage M4001, there are provided a carriage cover M4002, engaged with the carriage M4001, for guiding the recording head H1001 to a predetermined mounting position on the carriage M4001, and a head setting lever M4007, engaged with the tank holder 1500 of the recording head H1001 (shown in FIG. 3), for pressing the recording head H1001 so as to be set to a predetermined mounting position. That is, the head setting lever M4007 is provided at an upper portion of the carriage M4001 so as to be rotatable around a head setting lever shaft. A head setting plate (not shown) urged by a spring is provided at a portion engaged with the recording head H1001. The recording head H1001 is mounted on the carriage M4001 by being pressed by the spring force of the spring.

On another engaged portion with the recording head H1001 of the carriage M4001, there is provided a contact flexible printed circuit cable (shown in FIG. 7, hereinafter termed a "contact FPC") E0011 at another engaged portion with the recording head H1001. Contact portions on the contact FPC E0011 and portions (the external-signal input terminal) H1301 (shown in FIG. 5) provided on the recording head H1001 electrically contact to each other, so as to allow transmission/reception of various types of information for recording, supply of electric power to the recording head H1001, and the like.

An elastic member (not shown) made of rubber or the like is provided between the contact portions of the contact FPC E0011 and the carriage M4001, in order to allow secure contact between the contact portions and the carriage M4001 by the elastic force of the elastic member and the pressing force of the spring of the head setting lever M4007. The contact FPC E0011 is connected to a carriage substrate E0013 mounted on the back of the carriage M4001 (shown in FIG. 7).

3. Scanner

The printer of the first embodiment may also be used as a reading apparatus by mounting a scanner on the carriage M4001 (shown in FIG. 2) instead of the recording-head cartridge H1000.

The scanner moves in the main scanning direction together with the carriage M4001 of the printer, in order to read an image of an original fed instead of the recording medium, during the movement. By alternately performing a reading operation in the main scanning direction and a feeding operation in the sub-scanning direction of the original, information relating to the image of one original can be read.

FIGS. 6A and 6B are schematic diagrams illustrating the configuration of the above-described scanner M6000, as seen from opposite sides.

As shown in FIGS. 6A and 6B, a scanner holder M6001 is substantially box-shaped, and incorporates an optical system, a processing circuit and the like necessary for reading. When mounting the scanner M6000 into the carriage M4001, a reading unit lens M6006 is provided at a portion facing the surface of an original document to be scanned. The image of the original is read by focusing reflected light from the surface of the original onto an internal reading portion. An illuminating unit lens M6005 incorporates a light source (not shown). Light from the light source is projected onto the original via the lens M6005.

A scanner cover M6003 fixed on the base of the scanner holder M6001 is fitted so as to perform light blocking of the inside of the scanner holder M6001. It is intended to improve the operability in detachable mounting of the scanner cover M6003 with respect to the carriage M4001 by means of a louver-shaped grasping unit provided at a side. The scanner holder M6001 has substantially the same outer shape as the recording head H1001, and can be detachably mounted in the carriage M4001 by an operation similar to the operation when mounting the recording-head cartridge H1000.

A substrate having a reading processing circuit is accommodated in the scanner holder M6001, and a scanner contact PCB (printed circuit board) M6004 connected to this substrate is exposed to the outside. When mounting the scanner M6000 in the carriage M4001, the scanner contact PCB M6004 contacts the contact FPC E0011 at the carriage M4001, so as to electrically contact the substrate to a control system of the apparatus main body M1000 via the carriage M4001.

4. Configuration of Electric Circuitry of the Printer

Next, a description will be provided of the configuration of electric circuitry in the first embodiment with reference to FIG. 7.

The electric circuitry in the first embodiment includes a carriage substrate (CRPCB) E0013, a main PCB E0014, a power-supply unit E0015, and the like. The power-supply unit E0015 is connected to the main PCB E0014, and supplies various types of driving electric power. The carriage substrate E0013 is a PCB unit mounted on the carriage M4001 (shown in FIG. 2). In addition to operating as an interface for transmitting/receiving signals with the recording head H1001 (not shown) via the contact FPC E0011, the carriage substrate E0013 detects changes in the positional relationship between an encoder scale E0005 and an encoder sensor E0004 based on a pulse signal output from the encoder sensor E0004 in accordance with the movement of the carriage M4001, and outputs an output signal to the main PCB E0014 via a flexible flat cable (CRFFC) E0012.

The main PCB E0014 is a PCB unit for controlling driving of respective units of the ink-jet recording apparatus of the first embodiment, and has I/O (input/output) ports for a paper-end detection sensor (PE sensor) E0007, an ASF (automatic sheet feeding) sensor E0009, a cover sensor E0022, a parallel interface (I/F) E0016, a serial interface (I/F) E0017, the resumption key E0019, the LED E0020, the power supply key E0018, the buzzer E0021 and the like thereon. The main PCB E0014 is also connected to a motor (CR motor) E0001, serving as a driving source for causing the carriage M1400 to perform main scanning, a motor (LF motor) E0002, serving as a driving source for conveying a recording medium, and a motor (PG motor) E0003 used for a recording-head rotating operation and a sheet feeding operation, in order to control driving for these motors, and also has connection interfaces with an ink-empty sensor E0006, a GAP sensor E0008, a PG sensor E0010, the CRFFC E0012 and the power-supply unit E0015.

FIG. 8 is a block diagram illustrating the internal configuration of the main PCB E0014. In FIG. 8, a CPU (central processing unit) E1001 incorporates a clock-signal generator (CG) E1002 connected to an oscillation circuit E1005, and generates a system clock signal based on an output signal E1019 from the oscillation circuit E1005. The CPU E1001 is connected to a ROM (read-only memory) E1004 and an ASIC E1006 via a control bus E1014, and controls the ASIC E1006 and detects the states of an input signal E1017 from the power-supply key E0018, an input signal E1016 from the resumption key E0019, a cover detection signal E1042 and a head detection signal (HSENS) E1013 in accordance with a program stored in the ROM E1004, drives the buzzer E0021 (shown in FIG. 7) using a buzzer signal (BUZ) E1018, detects the states of an ink empty detection signal (INKS) E1011 connected to an incorporated A/D (analog-to-digital) converter E1003, and a temperature detection signal (TH) from a thermistor, and performs various logic calculations, determination of conditions, and the like, in order to control driving of the ink-jet recording apparatus.

The head detection signal E1013 is a head mounting detection signal input from the recording head cartridge H1000 (shown in FIGS. 3-5) via the flexible flat cable E0012, the carriage substrate E0013 and the contact FPC E0011. The ink-empty detection signal E1011 is an analog signal output from the ink-empty sensor E0006 (shown in FIG. 8). The temperature detection signal E1012 is an analog signal from a thermistor (not shown) provided on the carriage substrate E0013.

A CR-motor driver E1008 uses a motor power supply (VM) E1040 as the driving source, and generates a CR-motor driving signal E1037 in accordance with a CR-motor control signal E1036 from the ASIC E1006, to drive the CR motor E0001. A LF/PG-motor driver E1009 uses the motor power supply E1040 as the driving source, generates a LF-motor driving signal E1035 in accordance with a pulse-motor (PM) control signal E1033 from the ASIC E1006 to drive a LF motor, and also generates a PG-motor driving signal E1034 to drive a PG motor.

A power-supply control circuit E1010 controls supply of electric power to each sensor having a light-emitting device, and the like in accordance with a power-supply control signal E1024 from the ASIC E1006. The parallel I/F E0016 transfers a parallel-I/F signal E1030 from the ASIC E1006 to a parallel I/F cable E1031 connected from the outside, and also transfers a signal from the parallel I/F cable E1031 to the ASIC E1006. The serial I/F E0017 transfers a serial-I/F signal E1028 from the ASIC E1006 to a serial-I/F cable E1029 connected from the outside, and also transfers a signal from the serial-I/F cable E0029 to the ASIC E1006.

On the other hand, a head power supply signal (VH) E1039, a motor-power-supply signal (VM) E1040 and a logic power supply signal (VDD) E1041 are supplied from the power-supply unit E0015. A head power supply ON signal (VHON) and a motor power supply ON signal (VMON) from the ASIC E1006 are input to the power-supply unit E0015, to control ON/OFF of the head power supply E1039 and the motor power supply E1040. The logic power supply (VDD) E1041 supplied from the power-supply unit E0015 is supplied to each unit inside and outside of the main PCB E0014 after being subjected to voltage conversion if necessary.

The head power supply signal E1039 is transmitted to the flexible flat cable E0011 after being smoothed on the main PCB E0014, and is used for driving the recording head cartridge H1000. A reset circuit E1007 detects a decrease in the voltage of the logic power supply signal E1041, and supplies the CPU E1001 and the ASIC E1006 with a reset signal (RESET) E1015 to perform initialization.

The ASIC E1006 is a one chip semiconductor integrated circuit, and is controlled by the CPU E1001 via the control bus E1014. The ASIC E1006 outputs the CR-motor control signal E1036, the PM-signal control signal E1033, the power supply control signal E1024, the head power supply ON signal E1022, the motor power supply ON signal E1023 and the like that have been described above, exchanges signals with the parallel I/F E0016 and the serial I/F E0017, detects the state of each of a PE detection signal (PES) E1025 from the PE sensor E0007, an ASF detection signal (ASFS) E1026 from the ASF sensor E0009, a GAP detection signal (GAPS) E1027 from the GAP sensor E0008 for detecting a gap between the recording head and the recording medium, and a PG detection signal (PGS) E1032 from the PG sensor E0010, and transmits data indicating the state to the CPU E1001 via the control bus E1014. Based on the input data, the CPU E1001 flashes the LED E0020 by controlling driving by an LED driving signal E1038.

The ASIC E1006 also generates a timing signal by detecting the state of an encoder signal (ENC) E1020, and controls a recording operation by interfacing with the recording-head cartridge H1000 using a head control signal E1021. The encoder signal (ENC) E1020 is an output signal from the CR encoder sensor E0004 input via the flexible flat cable E0012. The head control signal E1021 is supplied to the recording head H1000 via the flexible flat cable E0012, the carriage substrate E0013 and the contact FPC E0011.

FIG. 9 is a block diagram illustrating the internal configuration of the ASIC E1006.

In FIG. 9, as for connection between respective blocks, only the flow of data relating to control of the head and respective components, such as recording data, motor-control data and the like. In order to prevent complication in the description of FIG. 9, a control signal and a clock signal relating read/write of a register incorporated in each block, a control signal relating to DMA (direct memory access) control, and the like are omitted.

In FIG. 9, A PLL (phase-locked loop) controller E2002 generates a clock signal (not shown) to be supplied to most components within the ASIC E1006, in response to a clock signal (CLK) E2031 and a PLL control signal (PLLON) E2033 output from the CPU E1001.

A CPU interface (I/F) E2001 performs control of register read/write for each block, or the like (to be described later), supply of a clock signal to some blocks, reception of an interrupt signal, or the like (to be described later, not shown in FIG. 9), in accordance with a reset signal E1015, a software reset signal (PDWN) E2032 output from the CPU E1001, a clock signal (CLK) E2031, or a control signal from the control bus E1014, outputs an interrupt signal (INT) E2034 to the CPU E1001, in order to notify generation of interrupt within the ASIC E1006.

A DRAM (dynamic random access memory) E2005 has respective regions for a reception buffer storage E2010, a working buffer storage E2011, a printing buffer storage E2014, a development data buffer storage E2016, and the like, as a data buffer storage for recording, a motor-control buffer storage E2023 for motor control, and a scanner-reception buffer storage E2024, a scanner data buffer storage E2026, and a transmission buffer storage E2028 as buffer storages to be used in a scanner operation mode instead of the above-described buffer storages for recording.

The DRAM E2005 is also used as a working region necessary for the operation of the CPU E1001. That is, a DRAM control unit E2004 performs a reading/writing operation with respect to the DRAM E2005 by switching access from the CPU E1001 to the DRAM E2005 via the control bus E1014, and access from a DMA control unit E2003 (to be described later) to the DRAM E2005.

The DMA control unit E2003 receives a request (not shown) from each block, and performs DRAM access by outputting an address signal and a control signal (not shown), and, in a writing operation, write data E2038, E2041, E2044, E2053, E2055, E2057 or the like, to the DRAM control unit E2004. In a reading operation, read data E2040, E2043, E2045, E2051, E2054, E2056, E2058 or E2059 from the DRAM control unit E2004 to a block, serving as the source of the request.

An IEEE 1284 I/F E2006 operates as a two-way communication interface with an external host apparatus (not shown) via the parallel I/F E0016 by control of the CPU E1001 via the CPU I/F E2001, transmits data (PIF reception data E2036) received from the parallel I/F E0016 to a reception control unit E2008 according to DMA processing, during a recording operation, and transmits data (IEEE 1284 transmission data (RDPIF) E2059) stored in the transmission buffer storage E2028 within the DRAM E2005 to the parallel I/F E0016 according to DMA processing, during a scanner reading operation.

A universal serial bus (USB) I/F E2007 operates as a two-way communication interface with an external host apparatus (not shown) via the serial I/F E0017 by control of the CPU E1001 via the CPU I/F E2001, transmits data (USB reception data E2037) received from the serial I/F E0017 to the reception control unit E2008 according to DMA processing, during a printing operation, and transmits data (USB transmission data (RDUSB) E2058) stored in the transmission buffer storage E2028 within the DRAM E2005 to the serial I/F E0017 according to DMA processing, during a scanner reading operation. The reception control unit E2008 writes received data (WDIF) E2038 from an I/F selected from the 1284 I/FF E2006 and the USB I/F E2007 into a reception buffer write address managed by a reception buffer storage control unit E2039. A compression/expansion DMA controller E2009 reads received data (raster data) stored in the reception buffer E2010 from a reception buffer read address managed by the reception-buffer control unit E2039 by control of the CPU E1001 via the CPU I/F E2001, performs compression/expansion of read data (RDWK) E2040 in accordance with an assigned mode, and writes resultant data in a working buffer region as a recording-code string (WDWK) E2014.

A recording buffer transfer DMA controller E2013 reads recording codes (RDWP) E2043 stored in the working buffer storage E2011 by control of the CPU E1007 via the CPU I/F E2001, and transfers the respective recording codes by rearranging them in addresses in the printing buffer storage E2014 so as to be adapted to the data transfer order to the recording-head cartridge H1000, and transfers resultant data (WDWP E2044). A working area DMA controller E2012 repeatedly writes assigned working-field data (WDWF) E2042 in regions in a working buffer storage where transfer by the recording buffer transfer DMA controller E2013 has been completed by control of the CPU E1001.

A recording data development DMA controller E2015 reads recording codes written in the printing buffer storage by being rearranged and development data written in a development data buffer storage E2016, using a data-development timing signal E2050 from the head control unit E2018 as a trigger, and writes development recording data (RDHDG) E2045 in