Title: Tuner block for use in video signal receiving apparatus having modulator, tuner and IF/demodulator circuit
Abstract: A tuner block in which a modulator and an IF/demodulator circuit are integrally formed. The tuner block has a casing for accommodating a tuner, the IF/demodulator circuit and the modulator, and sixteen pins consecutively disposed at an outside of the casing. A number of the pins is reduced as compared with a conventional tuner block by supplying an electrical power to the modulator and the tuner through a common pin, dispensing with pins carrying unnecessary signals and pins which carry no signal and rearranging other pins. Potential for noise and interference between signals is reduced by maximizing displacements of connector pins which carry signals which are likely to interact. A switching arrangement provides for utilizing either a conventional tuner block or a tuner block according to the present invention on a circuit board.
Patent Number: 6,947,722 Issued on 09/20/2005 to Kim, et al.
| Inventors:
|
Kim; Chul-min (Suwon, KR);
Yoo; Seung-bong (Suwon, KR);
Suh; Yong-bum (Suwon, KR)
|
| Assignee:
|
Samsung Electronics Co., Ltd. (Suwon-Si, KR)
|
| Appl. No.:
|
045043 |
| Filed:
|
January 15, 2002 |
Foreign Application Priority Data
| Oct 10, 2001[KR] | 10-2001-62462 |
| Current U.S. Class: |
455/349; 334/85; 455/90.3; 455/130 |
| Intern'l Class: |
H04B 001/08 |
| Field of Search: |
455/1881,349,130,347,903,902,550.1,575.1,560.1,131,557,301,182.2,180.3,182.3,191.1
348/734,552,729,731
358/21.R,903,160
386/83,46
334/1-3,17,47,85,82
|
References Cited [Referenced By]
U.S. Patent Documents
| 4509210 | Apr., 1985 | Kohn.
| |
| 4569084 | Feb., 1986 | Takahama.
| |
| 4691378 | Sep., 1987 | Kumamoto et al.
| |
| 5355532 | Oct., 1994 | Kubo et al.
| |
| 5457817 | Oct., 1995 | Nagai et al.
| |
| 5475876 | Dec., 1995 | Terada et al.
| |
| 5710999 | Jan., 1998 | Iwase et al.
| |
| 5913173 | Jun., 1999 | Ohwaki et al.
| |
| 5915068 | Jun., 1999 | Levine.
| |
| 6404309 | Jun., 2002 | Hall et al.
| |
| 6483554 | Nov., 2002 | Kim.
| |
| 2003/0063225 | Apr., 2003 | Sasaki.
| |
| Foreign Patent Documents |
| 2369420 | Mar., 2000 | CN.
| |
| 484 051 | Jun., 1992 | EP.
| |
Primary Examiner: Urban; Edward
Assistant Examiner: Chow; Charles
Attorney, Agent or Firm: Staas & Halsey LLP
Claims
1. A tuner block comprising:
a tuner which tunes a broadcasting signal;
an IF/demodulator circuit which demodulates the broadcasting signal tuned by
the tuner;
a modulator which modulates an input video signal and an input audio signal into
an RF signal;
a single casing which accommodates the tuner, the IF/demodulator circuit and
the modulator, wherein the tuner, IF/demodulator circuit and the modulator are
integrally formed in the single casing minimizing noise and interference between
signals input to and output from the single casing; and
a plurality of pins disposed consecutively on an outer side of the casing, the
plurality of pins to input and/or output signals and a voltage to operate the tuner,
the IF/demodulator circuit and the modulator;
wherein one of the plurality of pins is a power supply pin through which an electrical
power is supplied from an outside power supply, and the tuner and the modulator
are connected commonly to the power supply pin inside of the casing.
2. The tuner block according to claim 1, wherein, among the plurality of pins,
a first pin through a fifth pin are used by the modulator, a sixth pin through
an eleventh pin and a fourteenth pin are used by the tuner, and a twelfth pin,
a thirteenth pin and a sixteenth pin are used by the IF/demodulator circuit.
3. The tuner block according to claim 2, wherein, among the plurality of pins,
a fifteenth pin is a reserved pin which is not used.
4. The tuner block according to claim 3, wherein, among the plurality of pins,
the third pin is the power supply pin.
5. The tuner block according to claim 4, wherein, among the plurality of pins,
a seventh pin is a clock input pin which inputs a clock signal for use in the modulator
and the tuner.
6. A tuner block comprising:
a tuner which tunes a broadcasting signal;
an IF/demodulator circuit which demodulates the broadcasting signal tuned by
the tuner;
a modulator which modulates an input video signal and an input audio signal into
an RF signal;
a casing which accommodates the tuner, the IF/demodulator circuit and the modulator;
and
a plurality of pins disposed consecutively on an outer side of the casing, the
plurality of pins to input and/or output signals and a voltage to operate the tuner,
the IF/demodulator circuit and the modulator;
wherein one of the plurality of pins is a power supply pin through which an electrical
power is supplied from an outside power supply, and the tuner and the modulator
are connected commonly to the power supply pin inside of the casing, and
wherein, among the plurality of pins,
the first pin is an audio input pin which inputs an audio signal transmitted
from an audio/video block,
the second pin is a channel selection pin which inputs a channel selection signal
which selects an output channel of the modulator,
the fourth pin is a control pin which inputs a control signal to convert between
a TV mode and a VCR mode, and
the fifth pin is a video input pin which inputs the input video signal.
7. The tuner block according to claim 6, wherein, among the plurality of pins,
the sixth pin is an automatic gain control pin which controls a gain of the broadcasting
signal tuned by the tuner,
the eighth pin is an AS pin which inputs a signal to select one of the tuner
and at least one other tuner,
the ninth pin is an SCL pin which inputs another clock signal used to communicate
with a CPU,
the tenth pin is an SDA pin which inputs a command transmitted from the CPU,
the eleventh pin is an AFT pin which outputs a reference voltage to the CPU,
to enable an automatic fine tuning, and
the fourteenth pin is a TU-V pin which outputs another reference voltage used
to determine local oscillation of a frequency required by a selected channel.
8. The tuner block according to claim 7, wherein, among the plurality of pins,
the twelfth pin is an audio output pin which outputs an audio signal demodulated
by the IF/demodulator circuit,
the thirteenth pin is an SIF output pin which outputs a sound sub-carrier, and
the sixteenth pin is a video output pin which outputs a video signal demodulated
by the IF/demodulator circuit.
9. A tuner block comprising:
a tuner which tunes a broadcasting signal;
an IF/demodulator circuit which demodulates the broadcasting signal tuned by
the tuner;
a modulator which modulates an input video signal and an input audio signal into
an RF signal;
a casing which accommodates the tuner, the IF/demodulator circuit and the modulator;
and
a plurality of pins disposed consecutively at intervals on an outer side of the
casing, the plurality of pins to input and/or output signals and a voltage to operate
the tuner, the IF/demodulator circuit and the modulator;
wherein the plurality of pins comprises,
an audio output pin which outputs an audio signal demodulated by the IF/demodulator
circuit,
a video output pin which outputs a video signal demodulated by the IF/demodulator
circuit, wherein the video output pin is distanced from the audio output pin by
at least four pin intervals,
an SIF output pin disposed adjacent to the audio output pin, the SIF output pin
to output a sound sub-carrier, and
a clock input pin distanced from the SIF output pin by at least six pin intervals,
the clock input pin to input a clock signal to the modulator and the tuner.
10. The tuner block according to claim 9, wherein the SIF output pin is disposed
between the audio output pin and the video output pin.
11. The tuner block according to claim 10, wherein:
a TU-V pin which outputs a reference voltage used to determine local oscillation
of a frequency required by a selected channel, and a reserved pin which is not
used, are disposed between the SIF output pin and the video output pin.
12. The tuner block according to claim 11, wherein:
a total number of the plurality of pins is sixteen,
the audio output pin, the SIF output pin, the TU-V pin, the reserved pin and
the video output pin are a twelfth pin through a sixteenth pin, respectively, among
the sixteen pins, and
the clock input pin is a seventh pin among the sixteen pins.
13. The tuner block according to claim 12, wherein;
among the sixteen pins, a first pin through a fifth pin are used by the modulator,
and a sixth pin through an eighth pin and an eleventh pin are used by the tuner.
14. The tuner block according to claim 13, wherein:
the first pin through the fifth pin are, respectively,
an audio input pin which inputs the input audio signal,
a channel selection pin which inputs a channel selection signal to select an
output channel of the modulator,
a power supply pin which supplies electrical power to the modulator and the tuner,
a control pin which inputs a control signal to convert between a TV mode and
a VCR mode, and
a video input pin which inputs the input video signal.
15. The tuner block according to claim 14, wherein,
the sixth pin is an automatic gain control pin which controls a gain of the broadcasting
signal tuned by the tuner, and
the eighth pin through the eleventh pin are, respectively, an AS pin which inputs
a signal to select one of the tuner and at least one other tuner, an SCL pin which
inputs another clock signal used to communicate with a CPU, an SDA pin which inputs
a command transmitted from the CPU, and an AFT pin which outputs another reference
voltage to the CPU, to enable an automatic fine tuning.
16. The interface circuit according to claim 14, further comprising:
a third jumper which completes a fifth of the plurality of circuit paths to connect
the third corresponding pin to a sound sub-carrier output to selectively use the
second tuner block;
a fourth jumper which completes a sixth of the plurality of circuit paths to
connect a fourth of the corresponding pins to an automatic fine tuning output to
selectively use the second tuner block; and
a fifth jumper which completes a seventh of the plurality of circuit paths to
connect a video output to a fifth of the corresponding pins to selectively use
the second tuner block.
17. A tuner block comprising:
a tuner which tunes a broadcasting signal;
an IF/demodulator circuit which demodulates the broadcasting signal tuned by
the tuner;
a modulator which modulates an input video signal and an input audio signal into
an RF signal; and
sixteen pins disposed consecutively on an outer side of the casing, the pins
to input and/or output signals and a voltage needed to operate the tuner, the IF
circuit and the modulator; wherein:
a first pin inputs the input audio signal,
a second pin inputs a channel selection signal to select an output channel of
the modulator,
a third pin inputs the voltage to the modulator and the tuner,
a fourth pin inputs a control signal to convert between a TV mode and a VCR mode,
a fifth pin inputs the input video signal;
a sixth pin inputs a signal to control a gain of the broadcasting signal tuned
by the tuner,
a seventh pin inputs a clock signal to the modulator and the tuner,
an eighth pin inputs an AS signal to select one of the tuner and at least one
other tuner,
a ninth pin inputs another clock signal used to communicate with a CPU,
a tenth pin inputs a command transmitted from the CPU,
an eleventh pin outputs a reference voltage to the CPU, to enable automatic fine
tuning,
a twelfth pin outputs an output audio signal demodulated by the IF/demodulator
circuit,
a thirteenth pin outputs a sound sub-carrier,
a fourteenth pin outputs another reference voltage to determine local oscillation
of a frequency required by the selected channel,
a fifteenth pin is a reserved pin which is not used, and
a sixteenth pin outputs an output video signal demodulated by the IF/demodulator
circuit.
18. An interface circuit for selectively using one of a first tuner block having
a first predetermined number of connector pins and a second tuner block having
a second predetermined number of connector pins, wherein a third predetermined
number of corresponding pins of the first and second predetermined numbers of pins
have different functional assignments, the interface circuit comprising:
a first switch which connects a first of the corresponding pins to a power supply
input voltage to selectively use the first tuner block or connects the first corresponding
pin to an audio output function to selectively use the second tuner block;
a second switch which disconnects a clock input signal from a second of the corresponding
pins to selectively use the first tuner block and connects the clock input signal
to the second corresponding pin to selectively use the second tuner block;
a third switch which connects the clock input signal to a third of the corresponding
pins to selectively use the first tuner block and disconnects the clock input signal
from the third corresponding pin to selectively use the second tuner block;
a fourth switch which connects the third corresponding pin to a sound sub-carrier
output to selectively use the second tuner block and disconnects the third corresponding
pin from the sound sub-carrier output to selective use the first tuner block;
a fifth switch which disconnects an automatic fine tuning output from a fourth
of the corresponding pins to selectively use the first tuner block and connects
the fourth corresponding pin to the automatic fine tuning output to selectively
use the second tuner block; and
a sixth switch which connects a video output to a fifth of the corresponding
pins to selectively use the second tuner block and disconnects the fifth corresponding
pin from the video output to selectively use the first tuner block.
19. An interface circuit for selectively using one of a first tuner block having
a first predetermined number of connector pins and a second tuner block having
a second predetermined number of connector pins, wherein a third predetermined
number of corresponding pins of the first and second predetermined numbers of pins
have different functional assignments, the interface circuit comprising:
a circuit board having a plurality of circuit paths, each circuit path connecting
a respective pin of the third predetermined number of corresponding pins with additional
circuitry, each of the plurality of circuits path having an opening in the circuit
path adapted to receive a jumper;
a first jumper which completes a first of the plurality of circuit paths to connect
a first of the corresponding pins to a power supply input to selectively use the
first tuner block or completes a second of the plurality of circuit paths to connect
the first corresponding pin to an audio output to selectively use the second tuner
block; and
a second jumper which completes a third of the plurality of circuit paths to
connect a clock input to a second of the corresponding pins to selectively use
the second tuner block or completes a fourth of the plurality of circuit paths
to connect the clock input to a third of the corresponding pins to selectively
use the first tuner block.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Application No. 2001-62462 filed
Oct. 10, 2001, in the Korean Patent Office, the disclosure of which is incorporated
herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a tuner block for a broadcasting signal receiving
apparatus such as a VCR, and more particularly, to a tuner block having a modulator,
a tuner and IF/demodulator circuit which are built integrally in a casing.
2. Description of the Related Art
As shown in FIG. 1, a broadcasting signal receiving apparatus such as a VCR comprises
an A/V block 10 for processing a video signal and an audio signal, a deck
20 for recording/reproducing the video signal and the audio signal on/from
a recording medium such as a magnetic tape, a tuner block 50 for demodulating
the video signal and the audio signal from the broadcasting signal transmitted
through an antenna 60, and a CPU 30 which controls the broadcasting
signal receiving apparatus. The tuner block 50 has a tuner 53 for
tuning the broadcasting signal, an IF/demodulator circuit 55 for demodulating
the tuned broadcasting signal, and a modulator 51 for modulating the video
signal and the audio signal into an RF signal for a TV 70.
Generally, the modulator 51, the tuner 53, and the IF/demodulator
circuit 55 are integrally built in a casing, and such a device is called
as an integral-type of tuner block. The tuner block 50 is mounted on a printed
circuit board in the VCR. The tuner block 50 is connected with other devices
such as the A/V block 10 and the CPU 30 mounted on the printed circuit board.
FIG. 2 is a view showing an appearance of the conventional tuner block 50
that has the modulator 51, the tuner 53 and the IF/demodulator circuit
55 integrally formed therein. FIG. 3 is a view showing a layout of an arrangement
of a plurality of pins of the tuner block 50 shown in FIG. 2.
As shown in FIG. 2, the tuner block 50 has a casing 50
c for
embracing the modulator 51, the tuner 53, and the IF/demodulator
circuit 55, and an antenna input terminal 50
a and an antenna
output terminal 50
b disposed at an outside of the casing 50
c.
The antenna input terminal 50
a is connected with the antenna 60,
and the antenna output terminal 50
b is connected with the TV 70.
A length of the casing 50
c is standardized as 85 mm considering the
arrangement of the plurality of pins installed on the casing 50
c.
As shown in FIG. 3, twenty-two pins are installed in the casing 50
c.
The 22 pins consist of five pins (pin 1 through pin 5) corresponding
to the modulator 51, twelve pins (pin 6 through pin 16 and
pin 21) corresponding to the tuner 53, and five pins (pin 17
through pin 20 and pin 22) corresponding to the IF/demodulator circuit 55.
The five pins allocated to the modulator 51 comprise pin 1 and
pin 5 (AUDIO IN, VIDEO IN) to input the audio signal and the video signal,
respectively, pin 2 (CH/SW) to input a channel selection signal, pin 3
(MB (5V)) to supply electrical power needed for the modulator 51, and pin
4 (CONTROL) to input a control signal for a mode conversion between a TV
mode and a VCR mode.
The twelve pins allocated to the tuner 53 comprise pin 6 (RF AGC)
to control a gain of an input signal, pin 9 and pin 10 (SCL, SDA)
connected with control buses to communicate with the CPU 30 through I
2C
communication, pin 13 (X-TAL IN) to input a clock signal, etc. Among the
twelve pins allocated to the tuner 53, pin 7, pin 11, and
pin 15 are not used.
The five pins allocated to the IF/demodulator circuit 55 comprise pin
19 and pin 22 (AUDIO OUT, VIDEO OUT) to output an audio signal and
a video signal, respectively, pin 20 (SIF OUT) to output a sound sub-carrier,
etc. Among these pins allocated to the IF/demodulator circuit 55, pin 17
and pin 18 are not used.
Such an arrangement of the pins is determined considering the position of three
ICs (Integrated Circuits) corresponding to the modulator 51, the tuner 53,
and the IF/demodulator circuit 55 disposed in the casing 50
c.
In other words, the ICs, which correspond to the modulator 51, the tuner
53, and IF/demodulator circuit 55, are consecutively disposed from
an adjacent place to the antenna input terminal 50
a and the antenna
output terminal 50
b in the casing 50
c. Considering
the position of the ICs, the pins used by the modulator 51 are disposed
near to the antenna input terminal 50
a and the antenna output terminal
50
b, the pins used by the tuner 53 are disposed at a next
position, and the pins used by the IF/demodulator circuit 55 are disposed
at a farthest place from the antenna input terminal 50
a and the antenna
output terminal 50
b.
Moreover, the arrangement of the pins is determined considering a necessity
of maintaining a distance between pins which conduct signals that may cause interference
if the pins are disposed closely to each other. For example, where the video output
pin and the audio output pin are closely disposed, the video output signal causes
interference to the audio output signal, thus noise is added to the audio signal.
Therefore, the video output pin and the audio output pin are disposed respectively
at pin 22 and pin 19 so as to be spaced by more than a predetermined distance.
However, a size of the conventional tuner block 50 becomes unnecessarily
large since more pins are disposed than the number of pins actually needed for
the broadcasting signal receiving apparatus. In other words, as described above,
pins 7, 11, 15, 17, and 18 are not necessary
since these pins are not used. Yet, the conventional tuner block 50 has
the pins that are not used, thus the size of the tuner block 50 becomes
unnecessarily large. Thus, it is difficult to realize a compact broadcasting signal
receiving apparatus because of the unnecessarily large tuner block 50.
Recently, an IC having an integrally formed tuner and IF/demodulator circuit
has been developed. Therefore, a tuner block having simpler construction may be
manufactured by installing two ICs (a modulator IC and the integrated tuner and
IF/demodulator circuit IC) in the casing. Accordingly, a small-sized tuner block
may be created.
However, the arrangement of the pins according to the position of the modulator
IC and the integrated tuner and the IF/demodulator circuit IC in the casing 50
c,
and signal interference problem between the pins in accordance with the position
of the pins should be considered, even in the case of manufacturing the tuner block
by adopting the IC in which the tuner and the IF/demodulator circuit are integrally
formed. Therefore, to move some of the used pins to the position of the unused
pins (pin 7, 11, 15, 17, 18) to reduce the number
of the pins complicates construction of a circuit that connects the modulator IC
and the integrated tuner and IF/demodulator circuit IC in the casing 50
c
and increases a probability that noise caused by the signal interference will
be generated.
SUMMARY OF THE INVENTION
The present invention has been made to overcome the above-mentioned problems
of the related art. Accordingly, it is a first object of the present invention
to provide a small sized tuner block comprising an integrally formed modulator
and IF/demodulator circuit, wherein some pins of the small sized tuner block have
the same function as pins in a conventional tuner block.
A second object of the present invention is to provide a tuner block comprising
an integrally formed modulator and IF/demodulator circuit, which realizes a compact
casing and simplifies circuit construction in the casing, by determining positions
of the pins in consideration of a position of a modulator IC and an integrated
tuner and IF/demodulator circuit IC disposed in the casing.
A third object of the present invention is to provide a tuner block comprising
an integrally formed modulator and IF/demodulator circuit, which creates a compact
casing and minimizes the generation of a noise and interference between signals
due to the compact casing.
Additional objects and advantages of the invention will be set forth in
part in the description which follows, and, in part, will be obvious from the description,
or may be learned by practice of the invention.
To accomplish the first object and other objects of the invention, the present
invention comprises: a tuner which tunes a broadcast signal, an IF/demodulator
circuit which demodulates the broadcast signal, a modulator which modulates a video
signal and an audio signal into an RF signal, a casing which accommodates the tuner,
the IF/demodulator circuit and the modulator, and a plurality of pins, disposed
consecutively on an outside of the casing, which input and output signals and a
voltage to operate the tuner, the IF/demodulator circuit and the modulator.
Here, one of the plurality of pins is a power supply pin through which an electrical
power is supplied from an outside power supply. The tuner and the modulator are
commonly connected to the power supply pin at an inside of the casing, whereby
the tuner and the modulator are supplied with the electrical power required for
a normal operation thereof through the power supply pin. Since the modulator and
the tuner are supplied from a common pin, the number of the pins is reduced and
a tuner block may be manufactured which is smaller in size compared with the conventional
tuner block.
As shown in FIG. 5, a total number of pins is sixteen. Among the sixteen pins,
a first pin through a fifth pin are used by the modulator, a sixth pin through
an eleventh pin and a fourteenth pin are used by the tuner, and a twelfth, a thirteenth
pin and a sixteenth pin are used by the IF/demodulator circuit. In addition, a
fifteenth pin is a reserved pin, which is not used. The reserved pin may be removed,
reducing the total number of the pins to fifteen.
The third pin is a power supply pin, and the seventh pin is a clock input pin
to input a clock signal for use in the modulator and the tuner.
The tuner block to accomplish the second and the third object comprises: an audio
output pin which outputs an audio signal demodulated by the IF/demodulator circuit;
a video output pin distanced from the audio output pin at least by an interval
as much as four of the pins, a video output pin which outputs the video signal
demodulated by the IF/demodulator circuit; an SIF output pin disposed adjacent
the audio output pin, the SIF output pin outputting a sound sub-carrier; and a
clock input pin distanced from the SIF output pin at least by another interval
as much as six of the pins, the clock input pin inputting a clock signal for use
in the modulator and the tuner.
Preferably, the SIF output pin is disposed between the audio output pin
and the video output pin. Accordingly, the SIF pin and the clock input pin are
disposed for more than the distance of six pins as described above.
A TU-V pin which outputs a reference voltage used for a local oscillation of a
frequency required by a selected channel and a reserved pin, which is not used,
are disposed between the SIF output pin and the video output pin.
The total number of pins is sixteen. The audio output pin, the SIF output pin,
the TU-V pin, the reserved pin and the video output pin are respectively a twelfth
pin through a sixteenth pin among the sixteen pins, and the clock input pin is
a seventh pin.
The first pin through the fifth pin are used by the modulator. The pins are respectively:
an audio input pin which inputs the audio signal transmitted from an audio/video
block; a channel selection pin which inputs a channel selection signal which selects
an output channel of the modulator; a power supply pin which supplies an electrical
power to the modulator and the tuner; a control pin which inputs a control signal
for a mode conversion between a TV mode and a VCR mode; and a video input pin which
inputs the video signal transmitted from the audio/video block.
A sixth pin and an eighth pin through an eleventh pin are used by the tuner.
The
pins are respectively: an automatic gain control pin which controls a gain of the
broadcasting signal tuned by the tuner; an AS pin which inputs a signal which selects
the tuner to be controlled; an SCL pin which inputs another clock signal used for
a communication with respect to a CPU, an SDA pin which inputs a command transmitted
from the CPU; and an AFT pin which outputs another reference voltage provided to
the CPU, the another reference voltage being used for an automatic fine tuning.
Accordingly, the pins are disposed to correspond to the position of
the modulator IC and the integrated tuner and IF/demodulator IC installed in the
casing. Therefore, the compact tuner block may be realized and at the same time,
a circuit construction in the casing is simplified. Furthermore, interference between
the signals and the noise is minimized in the compact tuner block.
According to the present invention, the number of the pins is reduced to
sixteen and a small-sized tuner block is realized.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned objects and the feature of the present invention will be
more apparent by describing an embodiment of the present invention by referring
to the appended drawings, in which:
FIG. 1 is a schematic block diagram showing a conventional broadcasting signal
receiving apparatus;
FIG. 2 is a view showing an appearance of the tuner block having an integrated
modulator and an IF/demodulator circuit of FIG. 1;
FIG. 3 is a view showing a layout of pins of the tuner block of FIG. 2;
FIG. 4 is a view showing an appearance of the tuner block having an integrated
modulator and an IF/demodulator circuit according to the present invention;
FIG. 5 is a view showing a layout of pins of the tuner block in FIG. 4; and
FIG. 6A is a view showing a switching status of a printed circuit board adapted
to accommodate either the tuner block of FIG. 2 or the tuner block of FIG. 4
and showing a switching status for operation of the tuner block of FIG. 2.
FIG. 6B is a view showing a switching status of the printed circuit board shown
in FIG. 6A and showing a switching status for operation of the tuner block
of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the present embodiments of the
present invention, examples of which are illustrated in the accompanying drawings,
wherein like reference numerals refer to like elements throughout.
FIG. 4 is a view showing the appearance of a tuner block comprising a modulator
and an IF/demodulator circuit according to the present invention. The tuner block
150 comprises a modulator, a tuner, an IF/demodulator circuit and a casing
150c which accommodates the modulator, the tuner, and the IF/demodulator
circuit. An antenna input terminal
150a and an antenna output terminal
150b are installed at an outside of the casing
150c.
A modulator IC is disposed at an adjacent position to the antenna input terminal
150a and the antenna output terminal
150b in the casing
150c. An integrated tuner and IF/demodulator circuit IC is disposed
at a distant place from the position of the modulator IC.
Sixteen pins are disposed at a side of the casing
150c. The
physical construction of each of the sixteen pins, such as size and shape of a
pin, are the same as a pin of the conventional tuner block
50 in FIG. 2
and a distance between pins is the same as a distance between pins of the conventional
tuner block
50. The casing
150c is formed to have a length
of 60 to 65 mm, which is smaller than the conventional tuner block
50, since
the number of the pins is reduced compared to the conventional tuner block
50.
Preferably, the tuner block
150 according to the present invention has the
length of 65 mm as shown in FIG.
4.
FIG. 5 is a view showing a layout of pins used in the tuner block
150
of FIG.
4. Pin
1 and pin
5 (AUDIO IN, VIDEO IN) input an audio
signal and a video signal, respectively, transmitted from an audio/video block.
Pin
2 (CH/SW) inputs a channel selection signal (to select one channel between
channel
3 and channel
4) which selects an output channel of the modulator.
Pin
4 inputs a control signal which converts between a TV mode and a VCR mode.
Pin
3 (+B (TU/MD) supplies electrical power to the modulator and the tuner.
Thus, pin
1 through pin
5 are all used by the modulator. Among these
pins, pin
3 is used for supplying the electrical power not only to the modulator
but also to the tuner. To allow pin
3 to supply the electrical power to
both the modulator and the tuner, electrical power supply reeds of the modulator
IC and the integrated tuner and IF/demodulator circuit IC are commonly connected
with pin
3 in the casing
150c.
Pin
6 (RF AGC) inputs a bias voltage to control a gain of the broadcasting
signal tuned by the tuner. Pin
7 (X-TAL IN) inputs a clock signal for use
in the modulator and the tuner. Pin
8 (AS) inputs a signal for appointing
an address of a tuner to be controlled where there is a plurality of tuners. Pin
9 (SCL) inputs another clock signal used for communication with respect
to a CPU through an I
2C communication. Pin
10 (SDA) inputs a
command transmitted from the CPU through the I
2C communication. Pin
11 (AFT) outputs a reference voltage, which is provided to the CPU for an
automatic fine tuning. Pin
12 (AUDIO OUT) outputs the audio signal. Pin
13 (SIF OUT) outputs a sound sub-carrier (4.5 MHz in the case of an NTSC
method). Pin
14 (TU-V) outputs another reference voltage used for local
oscillation of a frequency required by a selected channel. Pin
15 is a reserved
pin, which is not used. Pin
16 (VIDEO OUT) outputs the video signal.
According to the above construction of the pins, pins
1 through
5 are used by the modulator, and pins
6 through
11 and
14
are used by the tuner. Pins
12,
13 and
16 are used by the
IF/demodulator circuit
55, and pin
15 is not used. Pin
3 and
pin
7 are used by both of the modulator and the tuner.
According to the arrangement of the pins as described above, among pins
allocated to the tuner
53 and the IF/demodulator circuit
55 in the
conventional tuner block
50 of FIG. 3, six pins (pin
17 through
22)
which are used in the conventional tuner block
50, are eliminated and functions
of the eliminated pins are included among the sixteen pins of the tuner block
150.
Actually, the IF/demodulator circuit
55 of the conventional tuner block
50 uses only four pins (pins
19 through
22), thus among pins
(pin
1 through
16) allocated to the modulator
51 and the tuner
53 of the conventional tuner block
50, five pins are required to
be reassigned to provide the interconnections previously provided by pins
19
through
22. Electrical power supply pin (pin
3) for the modulator
and the electrical power supply pin (pin
12) for the tuner in the conventional
tuner block
50 are integrated into pin
3 in the tuner block
150.
Considering that the IF OUT pin (pin
16) in the conventional tuner block
50 is only used for testing, the IF OUT function has been removed and the
VIDEO OUT function has been assigned to pin
16. Pin
15 is a reserved
pin in both the conventional tuner block
50 and the tuner block
150.
Where the reserved pin is also removed, the total number of the pins becomes fifteen.
In the tuner block
150 according to the present invention, the arrangement
of several pins is different from the conventional tuner block
50 as will
be described in great detail below.
The arrangement of pins
1 through
6, pins
8 through
10,
and pin
14 is the same as the arrangement of pins
1 through
6,
pins
8 through
10, and pin
14 of the conventional tuner block
50. However, in the conventional tuner block
50, pin
3 is
used for supplying the electrical power to the modulator, but in the tuner block
150 according to the present invention, pin
3 is used for supplying
the electrical power to both the modulator and the tuner.
The clock input pin (X-TAL IN), which was pin
13 in the conventional tuner
block
50, has been moved to pin
7, which was not used in the conventional
tuner block
50.
The audio output pin (AUDIO OUT), which was pin
19 in the conventional
tuner block
50, has been moved to pin
12, which was used in the conventional
tuner block
50 as power input for the tuner. Pin
12 of the conventional
tuner block
50, as described above, has been integrated with pin
3.
The video output (VIDEO OUT), which was pin
22 in the conventional tuner
block
50, has been moved to pin
16 which was used as IF OUT in the
conventional tuner block
50. As described above, in the tuner block
150
of the present invention, the IF OUT function has been removed.
The sub sound carrier signal (SIF OUT), which was pin
20 in the conventional
tuner block
50, has been moved to pin
13, which was used as the clock
input signal (X-TAL IN) in the conventional tuner block
50. The AFT signal,
which was pin
21 in the conventional tuner block
50, has been moved
to pin
11, which was not used in the conventional tuner block
50.
According to the above construction, the electrical power needed for the
tuner and the modulator is supplied through pin
3, some of the previously
reserved pins are used, the IF OUT function is eliminated, the number of the pins
is reduced from 22 to 16, and one reserved pin is retained.
Since the audio output pin (AUDIO OUT) and the video output pin (VIDEO OUT)
are respectively disposed at pin
12 and pin
16, the pins
12
and
16 are disposed to have an interval of four pins. Where the video output
and the audio output are output from pins adjacent to each other, the video output
becomes a noise source to the audio output. According to the present invention,
the distance between the video output pin (VIDEO OUT) and the audio output pin
(AUDIO OUT) becomes farther by one pin interval in comparison with that in the
conventional tuner block
50. Therefore, the influence of the video output
signal on the audio output signal becomes less, and the audio signal will have
a better quality.
In addition, according to the present invention, the audio output pin (AUDIO
OUT)
and the SIF OUT pin are adjacently disposed. The signals output from the audio
output pin (AUDIO OUT) and the SIF OUT pin are input to an AN block. Generally,
there are two types of the AN block: one is a mono model, and the other is a hi-fi
model having a hi-fi (Hi-Fi: High Fidelity) IC. The hi-fi IC generates a final
audio signal after a predetermined signal processing in regard to the output signal
of the SIF OUT pin, and passes through the output signal of the AUDIO OUT pin.
Therefore, in the case of hi-fi model having the hi-fi IC, the audio output signal
and the output signal of the SIF OUT pin are input to the AN block. For this end,
it is preferable that the audio output pin (AUDIO OUT) and the SIF OUT pin are
adjacently disposed. Accordingly, a circuit construction on a printed circuit board,
in which the tuner block
150 and the AN block are mounted, becomes simpler.
Since the SIF OUT pin and the clock input pin (X-TAL IN) are respectively disposed
at pin
13 and pin
7, the two pins are disposed to have an interval
of six pins. Since the clock signal (X-TAL IN) and the sound sub-carrier (SIF OUT)
are high frequency signals, where the SIF OUT pin and the clock input pin (X-TAL
IN) are adjacently disposed to each other, the clock signal and the sound sub-carrier
badly influence each other. Therefore, the SIF OUT pin and the clock input pin
(X-TAL IN) are preferably disposed as far from each other as possible. According
to the present invention, the position of the clock input pin (X-TAL IN) has been
moved to pin
7, which is the farthest pin from the SIF OUT pin
13
among the pins (
7,
11 and
15), which are not used in the conventional
tuner block
50. Thus, although the SIF OUT pin and the clock input pin (X-TAL
IN) are closer by 1 pin than in the conventional tuner block
50, an interval
large enough to prevent interference from being generated between the pins has
been maintained, and the number of the pins required to be moved in order to interconnect
the tuner block
150 is minimized
Furthermore, as described above, to maintain the interval between the
SIF OUT pin and the clock input pin (X-TAL IN), and the interval between the audio
output pin (AUDIO OUT) and the video output pin (VIDEO OUT), the SIF OUT pin is
preferably disposed between the audio output pin (AUDIO OUT) and the video output
pin (VIDEO OUT). In other words, in the present invention, the SIF OUT pin and
the audio output pin (AUDIO OUT) are not disposed at pin
12 and pin
13,
respectively, but are disposed at pin
13 and pin
12, respectively.
According to the above arrangement, the audio output pin (AUDIO OUT) and the video
output pin (VIDEO OUT) are disposed to have the interval of four pins as described
above, thus the AUDIO OUT pin and the VIDEO OUT pin are 1 pin further apart than
in the conventional tuner block
50. Moreover, according to the above arrangement,
also the SIF OUT pin and the clock input pin (X-TAL IN) are disposed to have the
interval of six pins.
An automatic fine tuning pin (AFT) is used by the tuner. Thus, it is preferable
that the automatic fine tuning pin (AFT) is disposed with other pins (pin
6
through
10) which are also used by the tuner, thus, the AFT pin is disposed
at pin
11.
Other pins excluding the pins moved as described above have been arranged as
in the conventional tuner block
50 to minimize the change of the position
of the pins compared with the conventional tuner block
50.
FIGS. 6A and 6B show a switching circuit of the printed circuit board
200,
on which the tuner block
150 in FIG. 5 is mounted. The switching circuit
shown in FIGS. 6A and 6B, is manufactured to accommodate either the conventional
tuner block
50 as shown in FIG. 6A, or the tuner block
150 according
to the present invention as shown in FIG. 6B, on the printed circuit board
200.
As shown in FIGS. 6A and 6B, a clock signal input (X-TAL IN) line is connected
with pin
7 and pin
13 through a first clock switch
211 and
a second clock switch
212. Where the conventional tuner block
50
is mounted on the printed circuit board
200, the first clock switch
211
is off and the second clock switch
212 is on as shown in FIG.
6A.
Where the tuner block
150 of the present invention is mounted on the printed
circuit board
200, the first clock switch
211 is on and the second
clock switch
212 is off as shown in FIG.
6B.
An ATF output line is connected with pin
21, and connected with pin
11
via an AFT switch
220. Where the conventional tuner block
50 is mounted
on the printed circuit board
200, the AFT switch
220 is off as shown
in FIG. 6A, and where the tuner block
150 according to the present invention
is mounted on the printed circuit board
200, the AFT switch
220 is
on as shown in FIG.
6B.
An SIF output line (SIF OUT) is connected with pin
20 and connected with
pin
13 via an SIF switch
240. Where the conventional tuner block
50 is mounted on the printed circuit board
200, the SIF switch
240
is off as shown in FIG. 6A, and where the tuner block
150 according to the
present invention is mounted on the printed circuit board
200, the SIF switch
240 is on as shown in FIG.
6B.
A video signal output line (VIDEO OUT) is connected with pin
22 and connected
with pin
16 via a video switch
250. Where the conventional tuner
block
50 is mounted on the printed circuit board
200, the video switch
250 is off as shown in FIG. 6A, and where the tuner block
150 according
to the present invention is mounted on the printed circuit board
200, the
video switch
250 is on as shown in FIG.
6B.
An electrical power supply line (Vcc 5V) is connected with pin
3, and
an
audio output (AUDIO OUT) line is connected with pin
19. The electrical power
supply line (Vcc 5V) and the audio output (AUDIO OUT) line are connected with pin
12 through a conversion switch
230. Where the conventional tuner
block
50 is mounted on the printed circuit board
200, the conversion
switch
230 is switched to connect pin
12 with the electrical power
(Vcc 5V) as shown in FIG. 6A, and where the tuner block
150 according to
the present invention is mounted on the printed circuit board
200, the conversion
switch
230 is switched to connect pin
12 with the audio output (AUDIO
OUT) line as shown in FIG.
6B. Therefore, where the conventional tuner block
50 is mounted, the electrical power is supplied to the modulator through
pin
12, and where the tuner block
150 according to the present invention
is mounted, the audio signal output through pin
12 is transmitted to the
ANV block.
Each of the switches
211,
212,
220,
230,
240
and
250 is realizable by using a jumper which determines an electrical connection
status on the printed circuit board
200. In other words, by changing the
installation position of the jumper installed on the printed circuit board
200,
the electrical connection status between the parts mounted on the printed circuit
board
200 is changed. Therefore, without changing the arrangement of holes
which are formed on the printed circuit board
200 for mounting the tuner
block, the electrical connection status of the printed circuit board
200
is changeable to be used with either the conventional tuner block
50 or
the tuner block
150 according to the present invention.
One way of changing the electrical connection status is to change a jumper installation
program of a chip mounting apparatus. Another way of changing the electrical connection
status is to manufacture the printed circuit board
200 to include the switches
211,
212,
220,
230,
240 and
250, and
allow the switching status to be changed in accordance with the mounted tuner block
selected from one of the conventional tuner block
50 and the tuner block
150 according to the present invention. Consequently, the tuner block
150
may be used interchangeably with the conventional tuner block by appropriately
setting the switches
211,
212,
220,
230,
240
and
250 as described above.
Since the electrical power for supplying the electrical power to the modulator
and the tuner is provided by a common pin (pin
3) in the tuner block
150,
the number of the pins is reduced, and a small-sized tuner block compared to the
conventional tuner block may be manufactured.
Moreover, each pin of the tuner bock
150 is disposed to correspond
to the position of the modulator IC and the integrated tuner and IF/demodulator
circuit IC disposed in the casing, thus the tuner block is compact, and at the
same time, the circuit construction in the casing is simplified. In addition, the
noise and interference between the signals in the tuner block
150 is minimized.
Furthermore, by changing installation positions of jumpers in the printed
circuit board, one of the conventional tuner block and the tuner block according
to the present invention is selectively installable. Compared with the conventional
tuner block
50, the number of the pins changed to result in the tuner block
150 is minimized, thus the number of jumpers which are changed in position
is reduced.
Although a few embodiments of the present invention have been shown and
described, it would be appreciated by those skilled in the art that changes may
be made in these embodiments without departing from the principles and spirit of
the invention, the scope of which is defined in the claims and their equivalents.
*
