Title: Optical component casing, optical device and projector
Abstract: An optical component casing (40) that houses a plurality of optical components including a reflection mirror (424) and disposes the plurality of optical components on a planarly defined illumination optical axis (L1) has a holder (81) that holds the reflection mirror (424) and a housing main body (401) that houses the other optical components. A bulging portion (816) bulging in an out-plane direction of the reflection mirror (424) is formed on a side of the holder (81) opposite to the side on which the reflection mirror (424) is attached, the bulging portion (816) pivotally moving on the inner surface of the housing main body (401) to rotate the holder (81) relative to the housing main body (401), where a rotation center (P) of the holder (81) is substantially coincident with an intersecting point (Q) of the illumination optical axis (L1) and a reflection surface (424A) of the reflection mirror (424).
Patent Number: 6,994,438 Issued on 02/07/2006 to Uehara, et al.
| Inventors:
|
Uehara; Taisuke (Chino, JP);
Ushiyama; Tomiyoshi (Minowa-machi, JP);
Fujisawa; Shohei (Matsumoto, JP);
Okubo; Hirotatsu (Nagano, JP)
|
| Assignee:
|
Seiko Epson Corporation (Tokyo, JP)
|
| Appl. No.:
|
740492 |
| Filed:
|
December 22, 2003 |
Foreign Application Priority Data
| Dec 24, 2002[JP] | 2002-373203 |
| Current U.S. Class: |
353/119; 353/37; 353/84; 353/99; 348/742; 348/782; 348/785; 349/8; 349/113; 359/584; 359/633; 359/634; 359/862; 359/874; 359/875; 359/876 |
| Current Intern'l Class: |
G03B 21/28 (20060101); G02F 1/13.35 (20060101); G02B 26/08 (20060101); G02B 27/14 (20060101); G02B 7/18.2 (20060101) |
| Field of Search: |
353/119,20,30,31,33,34,37,38,57,66,74,78,81,82,94,97-99,84
348/739,744,750,751,756-759,766,771,781,782,825,828,742,785,786
349/5,7,8,25,30,37,113
362/293,362
359/197,212,214,220,237,449,515,528,543,578,584,633,634,730,838,839,849,850,862,872-876
|
References Cited [Referenced By]
U.S. Patent Documents
| 5182676 | Jan., 1993 | Iwai et al.
| |
| 5865521 | Feb., 1999 | Hashizume et al.
| |
| 2002/0140909 | Oct., 2002 | Tanaka.
| |
| 2002/0186352 | Dec., 2002 | Chen et al.
| |
| Foreign Patent Documents |
| A 8-304739 | Nov., 1996 | JP.
| |
| A 2002-287252 | Oct., 2002 | JP.
| |
Primary Examiner: Perkey; W. B.
Assistant Examiner: Blackman; Rochelle
Attorney, Agent or Firm: Oliff & Berridge, PLC
Claims
What is claimed is:
1. An optical component casing that houses a plurality of optical components
including a reflection mirror and disposes the plurality of optical components
on a planarly defined illumination optical axis, the casing comprising:
a holder that holds the reflection mirror;
a housing main body that houses the optical components other than the reflection
mirror; and
a bulging portion bulging in an out-plane direction of the reflection mirror,
the bulging portion being provided on a side opposite to a side of the holder on
which the reflection mirror is provided,
wherein the bulging portion is affixed to an arm whose pivotal movement pivotally
moves the bulging portion on an inner surface of the housing main body in conjunction
with the arm to rotate the holder relative to the housing main body, and
wherein the rotation center of the holder is substantially coincident with the
intersecting point of the planarly defined illumination optical axis and a reflection
surface of the reflection mirror.
2. The optical component casing according to claim 1, wherein the bulging portion
is comprised as a part of a sphere and the rotation center of the holder is substantially
coincident with the center of the sphere.
3. The optical component casing according to claim 1, wherein a recess is formed
on the inner surface of the housing main body at a position corresponding to the
pivoting surface of the bulging portion.
4. The optical component casing according to claim 1,
wherein the arm projects in the out-plane direction of the holder and is provided
on the top of the bulging portion, and
wherein a hole that receives the projection of the arm is formed on the housing
main body.
5. The optical component casing according to claim 1,
wherein a pair of projections projecting along a surface of the reflection mirror
are provided on both ends of the holder orthogonal to a plane including the illumination
optical axis,
wherein the pair of projections are formed at a position where a line connecting
the central axes of the pair of projections passes the rotation center of the holder, and
wherein a support surface that supports the pair of projections so that the rotation
center of the holder is located on a plane including the illumination optical axis
is formed on the inner surface of the housing main body.
6. An optical device that separates a light beam irradiated by a light source
into a plurality of color lights, comprising:
the optical component casing according to claim 1; and
a plurality of mirrors housed in the optical component casing,
wherein the plurality of mirrors includes a total reflection mirror that reflects
all of the light and a wavelength-selection mirror that transmits a light of a
predetermined wavelength and reflects the rest of the light, and
wherein the total reflection mirror or the wavelength-selection mirror is attached
to the holder.
7. A projector that modulates a light beam irradiated by a light source in accordance
with image information to form an optical image, the optical image being projected
in an enlarged manner, comprising:
the optical device according to claim 6.
8. The projector according to claim 7, wherein the bulging portion is comprised
as part of a sphere and the rotation center of the holder is substantially coincident
with the center of the sphere.
9. The projector according to claim 7, wherein a recess is formed on the inner
surface of the housing main body at a position corresponding to the pivoting surface
of the bulging portion.
10. The projector according to claim 7, wherein the arm projects in the out-plane
direction of the holder and is provided on the top of the bulging portion, and
wherein a hole that receives the projection of the arm is formed on the housing
main body.
11. The projector according to claim 7,
wherein a pair of projections projecting along a surface of the reflection mirror
are provided on both ends of the holder orthogonal to a plane including the illumination
optical axis,
wherein the pair of projections are formed at a position where a line connecting
the central axes of the pair of projections passes the rotation center of the holder, and
wherein a support surface that supports the pair of projections so that the rotation
center of the holder is located on a plane including the illumination optical axis
is formed on the inner surface of the housing main body.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical component casing, an optical device
and a projector capable of adjusting an attitude of a reflection mirror.
2. Description of Related Art
Conventionally, so-called three-plate projectors have been used,
where a light beam irradiated by a light source is separated into three color lights
of red, green and blue by a dichroic mirror, the separated color lights being respectively
modulated by three liquid crystal panels in accordance with image data, and the
modulated light beam is synthesized by a cross dichroic prism and a color image
is enlarged and projected on a screen (see Japanese Patent Laid-Open Publication
No. 2002-287252, [0026]-[0040], FIGS. 4 and 7).
Such projectors are provided with a plurality of reflection mirrors for reflecting
the light beam irradiated by the light source lamp and the color lights separated
by the dichroic mirror and introducing the light beam on the liquid crystal panel.
However, when the reflection mirrors are attached at a position shifted
relative to a predesigned position, the illumination optical axis of the light
beam irradiated by the reflection mirror is likely to be shifted from a desired position.
In the above case, since the light beam of the respective color lights is not
effectively introduced on the liquid crystal panel, the illuminance may be deteriorated
or a shadow is displayed on a screen.
Further, the effective illumination area on which the respective color lights
are effectively synthesized may be narrowed to generate color shadings and a part
of the incident light may not be used for projecting the image.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an optical component casing,
an optical device and a projector capable of easily and accurately adjusting the
illumination optical axis of the light beam irradiated by a reflection mirror.
An optical component casing according to an aspect of the present invention houses
a plurality of optical components including a reflection mirror and disposes the
plurality of optical components on a planarly defined illumination optical axis,
the casing including: a holder that holds the reflection mirror; a housing main
body that houses the optical components other than the reflection mirror, and a
bulging portion bulging in an out-plane direction of the reflection mirror, the
bulging portion being provided on a side of the holder opposite to a side on which
the reflection mirror is provided, in which the bulging portion pivotally moves
on an inner surface of the housing main body to rotate the holder relative to the
housing main body, and the rotation center of the holder is substantially coincident
with the intersecting point of the illumination optical axis and a reflection surface
of the reflection mirror.
According to the above aspect of the present invention, since the bulging
portion bulging in the out-plane direction of the reflection mirror is formed on
the side of the holder opposite to the side on which the reflection mirror is provided
and the holder is rotated by pivotally moving the bulging portion on the inner
surface of the housing main body, the rotation center of the holder being substantially
coincident with the intersecting point of the illumination optical axis and the
reflection surface of the reflection mirror, the displacement of the illumination
optical axis of the light beam irradiated by the reflection mirror (referred to
as an irradiation light beam illumination optical axis hereinafter) when the holder
is rotated by a predetermined angle while the light beam is incident on the reflection
mirror along the illumination optical axis becomes smaller than an arrangement
where the rotation center holder is not substantially coincident with the intersecting
point of the illumination optical axis and the reflection surface.
Accordingly, the irradiation light illumination optical axis can be
easily and accurately adjusted.
In the above aspect of the present invention, the bulging portion may preferably
be defined as a part of a sphere and the rotation center of the holder may preferably
be substantially coincident with the center of the sphere.
According to the above arrangement, since the bulging portion is formed
as the part of the sphere and the center of the sphere is substantially coincident
with the rotation center of the holder, the bulging portion can be smoothly pivoted
on the inner surface of the housing main body.
Accordingly, the irradiation light illumination optical axis can be
more accurately adjusted since the holder can be smoothly rotated.
In the above aspect of the present invention, a recess may preferably be formed
on the inner surface of the housing main body at a position corresponding to the
pivoting surface of the bulging portion.
According to the above arrangement, since the recess is formed at the position
corresponding to the pivoting surface of the bulging portion on the inner surface
of the housing main body, the position of the bulging portion can be determined
relative to the inner surface of the housing main body by engaging the bulging
portion with the recess.
Accordingly, the position shift of the rotation center when the holder
is rotated can be restrained as compared to an arrangement without the recess.
In the above aspect of the present invention, an arm projecting in the out-plane
direction of the holder may preferably be provided on the top of the bulging portion,
and a hole that receives the projection of the arm may preferably be formed on
the housing main body.
According to the above arrangement, since the arm projecting in the out-plane
direction of the holder is provided on the top of the bulging portion and a hole
for receiving the projection of the arm is formed on the housing main body, the
bulging portion can be pivotally moved from the outside, in other words, the holder
can be rotated even after the housing main body is closed with a cover.
Accordingly, the holder can be rotated without providing any special
dust-proof measures for the optical components housed in the housing main body.
In the above aspect of the present invention, a pair of projections projecting
along a surface of the reflection mirror may preferably be provided on both ends
of the holder orthogonal to a plane including the illumination optical axis, the
pair of projections may preferably be formed at a position where a line connecting
the central axes of the projections passes the rotation center of the holder, and
a support surface that supports the pair of projections so that the rotation center
of the holder is located on a plane including the illumination optical axis may
preferably be provided on the inner surface of the housing main body.
According to the above arrangement, since the pair of projections projecting
along the surface of the reflection mirror so that the line connecting the central
axes of the respective projections passes the rotation center of the holder are
provided on the ends of the holder orthogonal to a plane including the illumination
optical axis and the support surface for supporting the projections so that the
rotation center of the holder is located on a plane including the illumination
optical axis is formed on the inner surface of the housing main body, when the
holder is rotated in right and left directions, the projection is slid on the support
surface around the rotation center and, when the holder is vertically rotated,
the projection is turned on the support surface around the central axis.
Accordingly, by providing the projection and the support surface, the
downward shift of the rotation center on account of the self-weight of the holder
can be trained as compared to an arrangement without the projection and the support surface.
Further, by supporting the projection on the support surface, the holder
can be temporarily set inside the housing main body. Accordingly, the installation
process and the attitude-adjusting process of the holder can be independently conducted,
so that the attitude adjusting process can be efficiently conducted.
An optical device according to another aspect of the present invention separates
a light beam irradiated by a light source into a plurality of color lights, the
optical device including: the above optical component casing; and a plurality of
mirrors housed in the optical component casing, in which the plurality of mirrors
includes a total reflection mirror that reflects all of the light and a wavelength-selection
mirror that transmits a light of a predetermined wavelength and reflects the rest
of the light, and the total reflection mirror or the wavelength-selection mirror
is attached to the holder.
According to the above aspect of the present invention, the same effect
and advantages as the above-described optical component casing can be obtained,
and the light beam irradiated by the light source can be securely separated into
a plurality of color lights.
A projector according to still another aspect of the present invention modulates
a light beam irradiated by a light source in accordance with image information
to form an optical image, the optical image being projected in an enlarged manner,
the projector having the above optical device.
According to the above aspect of the present invention, the same effect
and advantages as the above-described optical device can be obtained, and a high
illuminance and high quality optical image can be projected in an enlarged manner.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing an exterior arrangement of a projector
according to an embodiment of the present invention;
FIG. 2 is a perspective view showing the exterior arrangement of the projector
of the aforesaid embodiment;
FIG. 3 is a perspective view showing an internal arrangement of the projector
of the aforesaid embodiment;
FIG. 4 is a perspective view showing the internal arrangement of the projector
of the aforesaid embodiment;
FIG. 5 is a perspective view showing the internal arrangement of the projector
of the aforesaid embodiment;
FIG. 6 is a perspective view showing a structure of a light guide housing an
optical unit of the aforesaid embodiment;
FIG. 7 is a schematic illustration showing a structure of the optical unit of
the aforesaid embodiment;
FIG. 8 is a perspective view showing a structure of an optical device of the
aforesaid embodiment;
FIG. 9 is a perspective view showing cooling channels of the aforesaid embodiment;
FIG. 10 is a perspective view showing the structure of the light guide housing
the optical unit of the aforesaid embodiment;
FIG. 11 is a exploded perspective view showing the structure of the light guide
housing the optical unit of the aforesaid embodiment; and
FIG. 12 is an orthographic view showing three aspects of an attitude-adjusting
structure of a reflection mirror of the aforesaid embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)
An embodiment of the present invention will be described below with reference
to the attached drawings.
(1) Exterior Arrangement
FIGS. 1 and 2 show a projector
1 according to an embodiment of the present
invention, where FIG. 1 is a perspective view showing the projector
1 from
the upper font side and FIG. 2 is another perspective view showing the projector
1 from the lower rear side thereof.
The projector
1 is an optical device that modulates a light beam irradiated
by a light source in accordance with image information to enlarge and project on
a projection surface such as a screen, which includes an exterior case
2
housing an apparatus body including an optical unit (described below) thereinside
and a projection lens
3 exposed from the exterior case
2. The projector
1 is installed in large-scale retail stores, public spaces and the like,
which provides image information to a large number of viewers by displaying a projection
image on a large screen.
The projection lens
3 is a projection optical system that enlarges and
projects an optical image formed by modulating a light beam irradiated by a light
source by a liquid crystal panel (optical modulator:described below) in accordance
with image information, which is constructed as a lens set housing a plurality
of lenses in a cylindrical lens barrel.
The exterior case
2 (casing) has a cover
10 that covers the apparatus
body that is a rectangular parallelepiped having greater depth along the projection
direction than the width orthogonal thereto, and a frame body (not shown) for securing
the strength of the casing.
The cover
10 has an upper case
11 covering the upper part of the
apparatus body, a lower case
12 covering the lower part of the apparatus
body, and a front case
13 covering the front part of the apparatus body.
The respective cases
11 to
13 are synthetic-resin-made articles integrally
molded by injection molding and the like.
The upper case
11 has an upper side
11A covering the upper part
of the apparatus body, lateral sides
11B and
11C extending approximately
vertically downward from both ends of the upper side
11A in the width direction,
and a rear side
11D extending from the rear end of the upper side
11A.
The ridge line where the upper side
11A and the lateral sides
11B
and
11C of the upper case
11 are intersected are chamfered from approximately
at the center to the rear end (in the projection direction) of the projector
1
to form a recess
111 dented along the ridge line. The recess
111
is formed to insert a pipe-shaped support member for connecting two projectors
1 when the two projectors
1 are stacked in use.
A slitted opening
112 for introducing a cooing air is formed on the lateral
side
11B.
An operation panel
14 for actuating and adjusting the projector
1
is provided approximately at the center of the upper side
11A. The operation
panel
14 has a plurality of switches including a power switch and adjustment
switches of image and sound, the adjustment switches on the operation panel
14
being operated to adjust the image quality and sound volume and the like when an
image is projected by the projector
1.
A plurality of holes
141 are formed on the front side (in projection direction)
of the upper side
11A, under which a sound-outputting speaker is housed.
The operation panel
14 and the speaker are electrically connected with
a control board of the apparatus body (described below) and an operation signal
from the operation panel
14 is processed by the control board.
The rear side
11D is a frame having an opening on the approximately entire
side thereof, the opening exposing connectors
15 for the image signal and
the like to be inputted and having an opening section for housing a light source
adjacent to the connectors
15, the opening section being ordinarily covered
with a light-source housing cover
16. Incidentally, the connectors
15
are electrically connected with the below-described control board, and the image
signal inputted through the connectors
15 is processed by the control board.
A cover
113 capable of attaching to and detaching from the upper case
11
is attached on the rear end of the upper side
11A and the upper end of the
rear side
11D and an extension board such as a LAN board can be inserted
inside the cover
113.
The lower case
12 is approximately symmetrical with the upper case
11
around the engaging surface with the upper case
11, which includes a bottom
side
12A, lateral sides
12B and
12C and a rear side
12D.
The upper ends of the lateral sides
12B and
12C and the rear side
12D engage with the lower end of the lateral sides
11B and
11C
and the rear side
11D of the upper case
11. Incidentally, the rear
side
12D has an opening section on the entirety thereof in the same manner
as the rear side
11D of the upper case
11, the opening section exposing
the above-described connectors
15 after being engaged and the cover
16
being attached extending over the opening sections.
Another opening is formed on the corner of the rear side
12D, from
which an inlet connector
17 is exposed. An opening
122 is formed
on the lateral side
12B at a position corresponding to the opening
112
formed on the lateral side
11B of the upper case
11.
A fixed leg
18 is provided on the bottom side
12A approximately
at
the center of the rear end of the projector
1 and adjustment legs
19
are provided on both front ends in width direction.
The adjustment leg
19 is constructed of a shaft member projecting from
the bottom side
12A in a manner advanceable and retractable in the out-plane
direction, the shaft member being housed inside the exterior case
2. The
advancement and retraction of the adjustment leg
19 relative to the bottom
side
12A can be adjusted by operating an adjustment button
191 provided
on the lateral side of the projector
1.
Accordingly, the vertical position of the projection image irradiated
by the projector
1 can be adjusted and the projection image can be formed
at an appropriate position.
A convex rib
20 extending approximately at the center of the bottom side
12A along the projection direction and a plurality of ribs
21 and
22 extending orthogonal to the rib
20 along the width direction of
the projector
1 are formed on the bottom side
12A. Though described
in detail below, an intake opening for drawing in the cooling air from the outside
is formed between the two ribs
21 at the middle section, the intake opening
being covered with a filter
23. Another intake opening
24 also for
drawing in the cooling air is provided on the rear side of the intake opening covered
with the filter
23, which, however, is not covered with a filter.
Four screw holes
21A are formed on the ends of the ribs
21 and
22 extending along the width direction of the projector
1. Metal
fittings used in suspending the projector
1 from the ceiling are attached
to the screw holes
21A.
An engaging portion
26 is formed on the rear end of the bottom side
12A
and a cover for covering the connectors
15 to prevent the dust and the like
from being adhered thereon is attached on the engaging portion
26.
The front case
13 has a front section
13A and an upper section
13B, and a rib
13C extending in an out-plane direction formed on
the outer circumference of the front section
13A, the rib
13C being
engaged with the distal end (i.e. projection direction) of the upper case
11
and the lower case
12.
The front section
13A is inclined from the bottom side
12A of the
lower case
12 to the upper side
11A of the upper case
11 in
a manner to be away from the projection surface. Such an arrangement is for directing
the front section
13A of the front case
13 toward the lower side
to prevent the adhesion of dust on the front case
13 when the projector
1 is suspended from the ceiling, which is effective in a ceiling-suspending
arrangement where maintenance work is more troublesome than a normal setting.
An opening
27 is formed approximately at the center of the front section
13A, and the projection lens
3 is exposed from the opening
27.
A slitted opening
28 is formed adjacent to the opening
27, and
the
air having cooled the inside of the apparatus body of the projector
1 is
discharged from the opening
28.
A hole
29 is formed around the corner of the front section
13A
and
a light-receiver
30 for receiving an operation signal from a remote controller
(not shown) is exposed from the hole
29.
Incidentally, the light-receiver
30 is also provided on the
rear side of the projector
1, which is located on the corner of the rear
side
11D of the upper case
11 as shown in FIG. 2. Accordingly, the
operation signal of the remote controller can be received from both the front side
and the rear side of the apparatus.
Though not specifically shown, the upper section
13B extends approximately
to the center of the upper side
11A of the upper case
11, which reaches
around the base end of the projection lens
3. Such arrangement is for exchanging
the projection lens
3 only by detaching the front case
13, where
the upper section
13B can be detached by detaching the front case
13
from the upper case
11 and the lower case
12 to expose an attachment
portion on the base end of the projection lens
3.
(2) Interior Arrangement
As shown in FIGS. 3 to 5, the apparatus body of the projector
1 is housed
inside the exterior case
2, the apparatus body including an optical unit
4, a control board
5 and a power supply block
6.
(2-1) Structure of Optical Unit
4
The optical unit
4 (optical engine) modulates the light beam irradiated
by a light source in accordance with image information to form an optical image
and forms a projection image on a screen through the projection lens
3,
which is installed with a light source and various optical components inside a
light guide
40 (optical component casing).
The light guide
40 includes a lower light guide
401 (housing main
body) and an upper light guide
402, both being synthetic resin article formed
by injection molding and the like.
As shown in FIG. 6, the lower light guide
401 has a light source housing
portion
401A for a below-described light source to be housed and a component
housing portion
401B for housing optical components, the component housing
portion
401B being formed in a container-shape constructed of a bottom portion
401C and a sidewall
401D of which an upper portion is opened, the
sidewall
401D being provided with a plurality of grooves
401E. Various
optical components of the optical unit
4 are attached to the groove
401E,
so that the respective optical components are accurately disposed on an illumination
optical axis defined within the light guide
40. The upper light guide
402
has a planar shape corresponding to the lower light guide
401, which is
a cover closing the upper side of the lower light guide
401.
An L-sided metal head
403 is disposed on the light-irradiation end of
the
lower light guide
401, where the below-described optical device
44
is attached to the horizontal section of L-shape of the head
403 and the
base end of the projection lens
3 is attached to the vertical section of
the L-shape.
As shown in FIG. 7, the inside of the light guide
40 is functionally separated
as an integrator illuminating optical system
41, a color-separating optical
system
42, a relay optical system
43 and the optical device
44.
Incidentally, the optical unit
4 of the present embodiment is used for a
three-plate projector, which is a spatial color-separating optical unit for separating
a white light irradiated by the light source into three color lights within the
light guide
40.
The integrator illuminating optical system
41 is an optical system for
equalizing the illuminance of the light beam irradiated by the light source on
a plane orthogonal to the illumination optical axis thereof, which includes a light
source
411, a parallelizing concave lens
412, a first lens array
413, a second lens array
414, a polarization converter
415
and a superposing lens
416.
The light source
411 has a light source lamp
417 as a radial light
source, a reflector
418 and a front glass
419 covering the light-irradiation
side of the reflector
418, where a radial light beam irradiated by the light
source lamp
417 is reflected and converted into an approximately parallel
light beam by the parallelizing concave lens
412 and the reflector
418
to irradiated toward the outside. A high-pressure mercury lamp is used as the light
source lamp
417 in the present embodiment, however, a metal halide lamp
and a halogen lamp may alternatively be used. Further, though the parallelizing
concave lens
412 is disposed on the irradiation side of the reflector
418
having an ellipsoidal mirror in the present embodiment, a parabolic mirror may
be used as the reflector
418.
The first lens array
413 has an arrangement where small lenses having
approximately rectangular profile (seen in the illumination optical axis direction)
arranged in a matrix. The respective small lenses separate the light beam irradiated
by the light source lamp
417 into sub-beams to irradiate in the illumination
optical axis direction. The profile of the respective small lenses is arranged
approximately similar to the shape of the image formation area of below-described
liquid crystal panels
441R,
441G and
441B. For instance, when
the aspect ratio (ratio between the horizontal and vertical dimensions) of the
liquid crystal panels
441R,
441G and
441B is 4:3, the aspect
ratio of the respective small lenses is also set as 4:3.
The second lens array
414 also has the small lenses arranged in a matrix.
The small lens array
414 together with the superposing lens
416 superposes
the image of the respective small lenses of the first lens array
413 on
the liquid crystal panels
441R,
441G and
441B.
The polarization converter
415 converts the light beam from the second
lens array
414 into a polarized light of a predetermined direction, which
enhances the light utilization efficiency of the optical device
44.
Specifically, the respective sub-beams converted into a single-type
polarized light by the polarization converter
415 are substantially superposed
on the liquid crystal panels
441R,
441G and
441B by the superposing
lens
416. Since the projectors using the liquid crystal panels
441R,
441G and
441B that modulate a polarized light can use only one type
of polarized light, approximately half of the light beam from the light source
lamp
417 that emits random polarized light cannot be used. Accordingly,
with the use of the polarization converter
415, the entire light beam emitted
by the light source lamp
417 is converted into a single-type polarized light
to enhance the light utilization efficiency of the optical device
44. Incidentally,
such polarization converter
415 is disclosed in, for instance, Japanese
Patent Laid-Open Publication No. H08-304739.
The color-separating optical system
42 has a reflection mirror
421
that bends the light beam irradiated by the integrator illumination optical system
41, two dichroic mirrors
422 and
423 and a reflection mirror
424, which separates the plurality of sub-beams irradiated by the integrator
illuminating optical system
41 into three color lights of red (R), green
(G) and blue (B) by the dichroic mirrors
422 and
423. Though described
below in detail, the attitude of the reflection mirror
424 can be adjusted
relative to the lower light guide
401.
The relay optical system
43 has an incident-side lens
431, a relay
lens
433 and reflection mirrors
432 and
434, which introduces
the color light (red light) separated by the color-separating optical system
42
toward the liquid crystal panel
441R
At this time, the dichroic mirror
422 of the color-separating optical
system
42 reflects the red light component and the green light component of the
light beam irradiated by the integrator illuminating optical system
41 and
transmits the blue light component The blue light transmitted by the dichroic mirror
422 is reflected by the reflection mirror
424 and reaches to the
liquid crystal panel
441B for blue color through a field lens
425.
The field lens
425 converts the respective sub-beams irradiated by the second
lens array
414 into a light beam parallel to the central axis (main beam)
thereof. The field lenses
425 provided on the light-incident side of the
other liquid crystal panels
441G and
441R works in the same manner.
In the red light and the green light reflected by the dichroic mirror
422,
the green light is reflected by the dichroic mirror
423 to reach the liquid
crystal panel
441G for green color through the field lens
425. On
the other hand, the red light is transmitted through the dichroic mirror
423
and passes the relay optical system
43 to reach the liquid crystal panel
441R for red light through the field lens
425.
Incidentally, the relay optical system
43 is used for the red
light in order to prevent the deterioration of the light utilization efficiency
on account of light dispersion caused by longer optical path of the red light than
the other color light. In other words, the relay optical system
43 is used
for directly transmitting the sub-beams incident on the incident-side lens
431
toward the field lens
425. Incidentally, though the red light among the
three color lights passes through the relay optical system
43, the blue
light may pass through the relay optical system
43, for instance.
The optical device
44 modulates the incident light beam in accordance
with image information to form a color image, which includes three incident-side
polarization plates
442 on which the respective color lights separated by
the color-separating optical system
42 are incident, the liquid crystal
panels
441R,
441G and
441B (optical modulator) disposed on
the downstream of the respective incident-side polarization plates
442,
a visual-angle corrector plate
443 and an irradiation-side polarization
plate
444 disposed on the downstream of the respective liquid crystal panels
441R,
441G and
441B, and a cross dichroic prism
445
(color synthesizing optical system).
The liquid crystal panels
441R,
441G and
441B uses, for
instance, a polycrystalline silicon TFT as a switching element, which includes
a panel body
4411 and a holding frame
4412 for housing the panel
body
4411 as shown in an example of the liquid crystal panel
441G
of FIG. 8. Incidentally, though not specifically commented in the following description,
the liquid crystal panels
441R and
441B are arranged approximately
the same as the liquid crystal panel
441G.
Though not illustrated, the panel body
4411 has a pair of opposing
transparent substrates with liquid crystal being sealed therein, and a dust-proof
glass is attached on the incident-side and the irradiation-side of the pair of
transparent substrates.
The holding frame
4412 has a recess for housing the panel body
4411,
and holes
4413 are formed on four corners thereof.
The incident-side polarization plate
442 disposed on the upstream of the
liquid crystal panels
441R,
441G and
441B (see FIG. 7) transmits
the polarized light in a predetermined direction among the respective color lights
separated by the color-separating optical system
42 and absorbs the other
light beam, the incident-side polarization plate
442 having a polarization
film being adhered on a substrate such as a sapphire glass. Alternatively, a polarization
film may be attached on the field lens
425.
The visual-angle corrector plate
443 has a substrate on which an optical
conversion film for correcting the visual-angle of the optical image formed by
the liquid crystal panel
441G, the visual-corrector plate
443 decreasing
the light leakage on a black screen and greatly enhancing the contrast of the projection image.
The irradiation-side polarization plate
444 transmits a polarized light
in a predetermined direction and absorbs the other light beam modulated by the
liquid crystal panel
441G, which is constructed of two polarization plates,
i.e. a first polarization plate
444P (pre-polarizer) and a second polarization
plate
444A (analyzer). The double-plate structure of the irradiation-side
polarization plate
444 is for absorbing the incident polarized light respectively
by the first polarization plate
444P and the second polarization plate
444A
to proportionally distribute the heat generated on the polarization plate
444P
and
444A by the polarized light to restrain the overheating of the respective
polarization plates.
The cross dichroic prism
445 synthesizes the optical image irradiated
by the irradiation-side polarization plate
444 and modulated for each color
light to form a color image.
In the cross dichroic prism
445, a dielectric multi-layer film for reflecting
red light and another dielectric multi-layer film for reflecting blue light are
provided approximately in X-shape along the boundaries of the four right-angle
prisms, the dielectric multi-layer films synthesizing the three color lights.
A prism-fixing plate
4451 is fixed on the lower side of the cross dichroic
prism
445 by an ultraviolet-curing adhesive. The prism-fixing plate
4451
has legs
4452 extending along the diagonal lines of the cross dichroic prism
445 and a hole
4453 is formed on the distal end of the respective
legs
4452.
The optical device
44 is attached on the horizontal section of the L-shaped
head
403 by a screw etc. (not shown) inserted to the hole
4453.
The liquid crystal panel
441G, the visual-angle corrector plate
443,
the first polarization plate
444P and the second polarization plate
444A
are fixed on the light-incident side of the cross dichroic prism
445 through
a panel-fixing plate
446.
The panel-fixing plate
446 has a fixing portion body
4461 having
an approximately C-shaped cross section, and a pin
4463 projecting on the
light-incident side of the fixing portion body
4461 through an arm
4462.
On the light-incident side of the fixing portion body
4461, a base
4464
for the visual-angle corrector plate
443 to be fixed and a positioning portion
4464A extending along the light-incident side of the fixing portion body
4461 for defining the outer shape position of the visual-angle corrector
plate
443 are formed.
When the liquid crystal panel
441G, the visual-angle corrector plate
443, the first polarization plate
444P and the second polarization
plate
444A are fixed on the light-incident side of the cross dichroic prism
445 by the panel-fixing plate
446, the first polarization plate
444P
and the second polarization plate
444A are inserted into a space defined
by the C-shape of the fixing portion body
4461, and the polarization plates
444P and
444A are fixed inside the space while being biased by a
spring member
4465-with a predetermined gap secured therebetween.
Subsequently, while adjusting the outer shape position of the visual-angle
corrector plate
443 with the positioning portion
4464A, a side of
the visual-angle corrector plate
443 is adhered on the base
4464
by a heat-conductive tape or an adhesive and the panel-fixing plate
446
is fixed on the light-incident side of the cross dichroic prism
445.
Then, after an ultraviolet-curing adhesive is coated on the pin
4463
of the panel-fixing plate
446, the pin
4463 is inserted into the
hole
4413 on the liquid crystal panel
441G while the adhesive is uncured.
In the same manner, the liquid crystal panels
441R and
441B are
temporarily fixed on the panel-fixing plate
446 while the ultraviolet-curing
adhesive is uncured, and the red, green and blue lights are introduced on the liquid
crystal panels
441R,
441G and
441B. Then, while checking the
respective color lights irritated from the light-irradiation side of the cross
dichroic prism
445, the relative position of the liquid crystal panels
441R,
441G and
441B is adjusted, and, after completing the position adjustment,
ultraviolet is irradiated on the ultraviolet-curing adhesive to fix the liquid
crystal panels
441R,
441G and
441B.
(2-2) Structure of Control Board
5
As shown in FIGS. 4 and 5, the control board
5 is disposed to cover the
upper side of the optical unit
4 and has a main board
51 having a
two-stage structure including an upper board
511 on which a controller body
such as a processor is installed and a lower board
512 on which driver ICs
for the liquid crystal panels
441R,
441G and
441B are installed.
Though not illustrated, the control board
5 also has an interface board
that is connected on the rear side of the main board
51 and is vertically
mounted along the rear sides
11D and
12D of the exterior case
2.
The connectors
15 are installed on the backside of the interface board
and the image information inputted from the connectors
15 is outputted to
the main board
51 through the interface board.
The processor on the main board
51 outputs a control command to the driver
IC for the liquid crystal panel after processing the inputted image information.
The driver IC generates a drive signal in accordance with the control command to
drive the liquid crystal panel
441 to modulate the light beam in accordance
with the image information to form the optical image.
(2-3) Structure of Power Supply Block
6
The power supply block
6 extends in a projection direction of the exterior
case
2 of the projector
1 adjoining the optical unit
4, which
includes a power supply unit and a lamp driver unit (not shown).
The power supply unit supplies the electric power supplied from the outside through
a power cable connected with the above-described inlet connector
17 to the
lamp driver unit and the control board
5 etc.
The lamp driver unit is a converter for supplying the electric power to the above-described
light source
411 with a stable voltage. The commercial alternate-current
inputted from the power supply unit is rectified and converted by the lamp driver
unit to be supplied to the light source
411 as a direct-current or an alternate
rectangular wave current.
As shown in FIG. 3, an exhaust fan
61 is provided on the front side of
the power supply block
6, and the air having cooled the respective components
inside the projector
1 is concentrated by the exhaust fan
61 and
is discharged toward the outside of the apparatus from the opening
28 of
the exterior case
2.
(2-4) Cooling Mechanism
Since the inside of the projector
1 is heated by the heat-generating
light source
411 and the power supply block
6, a cooling air has
to be circulated therein to efficiently cool the light source
411, the optical
device
44 and the power supply block
6. Accordingly, three cooling
channels C
1, C
2 and C
3 are defined in the present embodiment
as shown in FIG. 9.
The cooling channel C
1 is a cooling channel for cooling the light source
411 and the polarization converter
415 of the integrator illumination
optical system
41, which supplies the cooling air drawn in by a sirocco
fan
71 provided inside the apparatus at the intake opening
24 shown
in FIG. 2 to the light source
411 and the polarization converter
415
from a side of the light source housing portion
401A of the light guide
40 by a duct
72 to cool the light source
411 and the polarization
converter
415. The air having cooled the components is drawn in by the exhaust
fan
61 to be discharged toward the outside of the projector
1.
The cooling channel C
2 is a cooling channel for cooling the optical device
44 that modulates the light beam and synthesizes the color lights, the cooling
channel C
2 supplying the cooling air drawn in by a sirocco fan (described
below) provided inside the apparatus at the intake opening formed at a position
where the filter
23 (FIG. 2) is provided from the lower side of the optical
device
44 to the upper side thereof to cool the liquid crystal panels
441R,
441G and
441B, the incident-side polarization plate
442, the
visual-angle corrector plate
443 and the irradiation-side polarization plate
444. The air having cooled the components flows along the lower side of
the main board
51 and the upper side
11A of the upper case
11,
which is discharged to the outside by the exhaust fan
61 while cooling the
circuit elements installed on the main board
51.
The cooling channel C
3 is a cooling channel for cooling the power supply
block
6, which draws in the cooling air from the opening
112 formed
on the lateral side
11B of the upper case
11 and the opening
122
formed on the lateral side
12B of the lower case
12 by an intake
fan
62 provided on the rear end of the power supply block
6, a part
of the drawn-in cooling air being supplied to the power supply unit and the lamp
driver unit to be discharged to the outside by the exhaust fan
61 after
cooling the components.
(2-5) Attitude Adjusting Mechanism of Reflection Mirror
424
As shown in FIG. 10, the reflection mirror
424 is held by a holder
81
that is rotated around a rotation center P relative to a sidewall
401D of
the lower light guide
401. The rotation center P substantially coincides
with an intersecting point Q of the defined illumination optical axis L
1
and a reflection surface
424A of the reflection mirror
424. Incidentally,
L
2 represents an irradiation light illumination optical axis (i.e. an illumination
optical axis of the light beam irradiated by the reflection surface
424A).
As shown in FIGS. 11 and 12(A) to (C), the holder
81 covers the reflection
mirror
424, which includes a rear section
811, lateral sections
812
and
813, an upper section
814 and a lower section
815.
The reflection mirror
424 is held on the front side of the rear section
811 by heat-caulking of a caulking portion
814A provided on the upper
section
814 and the lower section
815. The depth of the opening of
the holder
81 is greater than the reflection mirror
424, so that
the reflection surface
424A of the reflection mirror
424 is located
inward relative to the surface position of the opening of the holder
81.
A bulging portion
816 is formed approximately at the center of the backside
of the rear section
811, which is arranged as a part of a virtual sphere
S having the rotation center P as the center thereof.
A mirror-position adjusting lever
817 as an arm projecting in the out-plane
direction of the rear section
811 is provided on the top of the bulging
portion
816, and a semi-spherical mirror knob
818 connected to an
adjustment arm of an adjustment jig (not shown) is fixed on the distal end of the
mirror-position adjusting lever
817 by heat-caulking.
Cylindrical projections
819 projecting along the surface of the
reflection mirror
424 are provided on the lateral sections
812 and
813 so that a virtual line T connecting the central axes of the projections
819 passes the rotation center P.
A notch
812A is formed on the lower side of the lateral section
812.
Accordingly, even after the reflection mirror
424 is attached to the holder
81, the reflection mirror
424 can be easily detached by inserting
a jig having thin distal end into a space between the rear section
811 and
the reflection mirror
424 from the notch
812A.
As shown in FIG. 11, a recess
82 for the bulging portion
816 to
be engaged and a support surface
83 for supporting the projection
819
so that the rotation center P is located on a plane including the illumination
optical axis L
1 is provided on the sidewall
401D.
The recess
82 is formed in a shape corresponding to the spherical surface
of the bulging portion
816 so that the bulging portion
816 can be
smoothly pivoted. A hole
821 for exposing the mirror-position adjusting
lever
817 to the outside of the lower light guide
401 is provided
on top of the recess
82.
The hole
821 is formed in a circle with the upper part thereof being cut,
the cut portion being a notch
822 opening toward the upper side of the sidewall
401D. Accordingly, the mirror-position adjusting lever
817 can be
inserted from the upper side of the sidewall
401D to engage the bulging
portion
816 on the recess
82, thereby improving the workability therefor.
A constricted portion
823 is provided at the connection of the hole
821
and the notch
822. Accordingly, the position shift of the bulging portion
816 toward the upper side during the pivotal movement of the bulging portion
816 caused on account of the notch
822 can be restrained.
The support surface
83 is provided on the upper side of a shoulder portion
831 and formed in a planar shape having small friction coefficient. Accordingly,
the projection
819 can be smoothly rotated and slid.
The adjustment of the attitude of the reflection mirror
424 relative to
the lower guide
401, in other words, the irradiation light illumination
optical axis L
2 is adjusted by introducing a light beam into the light guide
40 and checking the light beam irradiated from the projection lens
3.
Specifically, after disposing the light source
411 and the respective
optical components in the lower light guide
401, a base resin of an instant
adhesive is coated on the bulging portion
816 or the recess
82 and
the mirror-position adjusting lever
817 is inserted from the upper side
of the notch
822 while the instant adhesive is uncured. As shown in FIGS.
12(A) to (C), after engaging the bulging portion
816 on the recess
82
and resting the projection
819 on the support surface
83, the upper
light guide
402 is attached and a light beam is irradiated on the reflection
surface
424A along the defined illumination optical axis L
1.
In this state, after an adjustment arm of an adjustment jig is attached on the
mirror knob
818 while applying a tensile force, the mirror-position adjustment
lever
817 is operated by the adjustment jig to pivotally move the holder
81 by pivotally moving the bulging portion
816 on the surface of
the recess
82 in vertical and horizontal directions, and by sliding or rotating
the projection
819 on the support surface
83 to adjust the attitude
of the reflection mirror
424.
For instance, when the mirror-position adjusting lever
817 is moved in
X
11 direction as shown in FIG. 12(A), the bulging portion
816 pivotally
moves along the surface of the recess
82 and the projection
819 slides
on the support surface
83 in X
12 direction around the rotation center
P on the virtual line T. Accordingly, the holder
81 is rotated in left direction
around the rotation center P.
Further, when the mirror-position adjusting lever
817 is moved in
Z
11 direction as shown in FIG. 12(B), the bulging portion
816 pivotally
moves along the surface of the recess
82, so that the projection
819
is turned on the support surface
83 in Z
12 direction around the virtual
line T passing the rotation center P. Accordingly, the holder
81 is vertically
rotated around the rotation center P.
When the mirror-position adjusting lever
817 is moved in X
21 direction
or Z
21 direction, the holder
81 is rotated rightward or downward
around the rotation center P in the same manner as described above.
After adjusting the attitude of the reflection mirror
424, i.e. the
irradiation light illumination optical axis L
2, by pivotally moving the
holder
81 in the same manner as described above while checking the light
beam irradiated by the projection lens
3, a hardening accelerator is coated
on the portion where the base resin of the instant adhesive is coated to bond the
bulging portion
816 and the recess
82 and an adhesive is coated on
the portion where the projection
819 touches the support surface
83
through a hole (not shown) formed on the upper light guide
402 to bond the
projections
819 and the support surface
83 to fix the reflection
mirror
424 after the position thereof being adjusted.
According to the present embodiment, following advantages can be obtained.
Since the bulging portion
816 is formed on the backside of the holder
81 holding the reflection mirror
424 and the bulging portion
816
pivotally moves on the inner surface of the sidewall
401D, the rotation
center P of the holder
81 being substantially coincident with the intersecting
point Q of the illumination optical axis L
1 and the reflection surface
424A
of the reflection mirror
424, the displacement of the irradiation light
illumination optical axis L
2 when the holder
81 is rotated by a predetermined
angle while the light bean is incident on the reflection mirror
424 along
the illumination optical axis L
1 becomes smaller than an arrangement where
the rotation center P is not substantially coincident with the intersecting point Q.
Accordingly, the irradiation light illumination optical axis L
2
can be easily and accurately adjusted.
Since the bulging portion
816 is formed as apart of the virtual sphere
S and the center of the virtual sphere S is made substantially coincident with
the rotation center P of the holder
81, the bulging portion
816 can
be smoothly pivoted on the inner s
