JPH0544874B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a TV receiver equipped with an RGB input terminal.

[Conventional technology]

In addition to the RF input terminal (antenna input terminal), RGB
Television receivers equipped with signal input terminals are known. RGB signal is called RGB connector
It is supplied externally via an EIAJ standard 21-pin multi-connector. This RGB connector includes an input terminal for a control signal called a Ys signal, and the internal signal and external signal are switched depending on the level of this Ys signal.

That is, when the Ys signal is “L”, the internal RGB signal is monitored, and when the Ys signal is “H”, the external RGB signal is monitored.
RGB signals are monitored. Therefore, while monitoring the internal RGB signal during one screen, Ys
It becomes possible to partially switch the signal to an external RGB signal and superimpose characters, etc.

Normally, video equipment with RGB output terminals are EIAJ
It is equipped with a Ys signal output terminal to comply with the standard, and can be connected to a television receiver via the RGB connector mentioned above. However, when connecting with non-standard equipment that derives RGB output but does not output the Ys signal, it cannot operate unless an "H" signal corresponding to the Ys signal is generated within the receiver. Note that in this case, the above-mentioned superimposition cannot be performed.

In addition, for TV receivers equipped with RGB input terminals,
Some devices have a picture adjustment knob for contrast (or brightness) adjustment for external RGB and internal RGB, while others have independent picture adjustment knobs for both. In the former, the external
Every time you switch between the RGB signal and the internal RGB signal,
Adjustments must be made to obtain the proper contrast for each. On the other hand, the latter method is complicated because the RGB level and video level must be adjusted using two picture adjustment knobs when superimposing.

[Problem that the invention seeks to solve]

In view of the above-mentioned problems, the present invention provides a control signal
Even when connected to a video device that does not output Ys, you can monitor external RGB input.
Furthermore, it eliminates the trouble of having to re-adjust the contrast (or brightness) of the image every time you switch between internal and external signals, and the trouble of having to adjust the contrast of each signal individually when superimposing internal and external signals. The purpose is to provide a television receiver that can

[Means for solving problems]

The television receiver of the present invention includes an RGB input terminal group (RGB connector 1 in the embodiment) including an input terminal for a control signal Ys for switching the RGB signal from an internal signal to an external signal.

A switch (forced Ys switch 6) is provided to force the input terminal of the control signal Ys to an external logic level.

Furthermore, mutually independent control means (picture control volume VR) that controls the brightness of each internal signal and external signal is provided.
1, VR2) is provided.

A changeover switch 7 is provided which is linked to the switch 6, and when the switch 6 is turned off,
The control signal of one of the control means is cut off, and the control signal of the other control means is used to control the brightness of both the internal signal and the external signal.

〔Example〕

The drawing shows the outside of a television receiver to which the present invention is applied.
FIG. 3 is a circuit diagram of a switching section for RGB signals and internal RGB signals.

RGB connector 1 in the figure is EIAJ standard TTC-003
"Interconnection of television receivers and peripheral devices"
(January 1983), and includes RGB input terminals 1a to 1c and an input terminal 1d for a control signal Ys.

RGB signals obtained from the RGB connector 1 are input to a switching circuit 2, and are applied to switching switches 4a to 4c via picture control circuits 3a to 3c. If the Ys signal is H, selector switch 4
A to 4c are on the external side, and RGB signals from the RGB connector 1 are derived as switching outputs.

If the Ys signal is L, selector switches 4a to 4
c is switched to the internal side, and an internal RGB signal obtained by processing the video signal of the RF demodulated output by the Y/C processor IC5 is derived instead.

In order to connect the television receiver of this embodiment to a video device that does not have a Ys signal output terminal, the Ys input of the switching circuit 2 is forcibly set to H level.
A switch 6 is provided. When this switch 6 is turned on to the power supply side, the buffer transistor T is turned on via the voltage dividing resistor, and a high level H pseudo
A Ys signal is applied to the Ys input line. Therefore, the switching circuit 2 is placed on the external side and can monitor external RGB signals.

The forced Ys switch 6 is set to superimpose off/on on the TV receiver panel, and when switch 6 is turned on (power side), superimpose is turned off, and switch 6 is turned off (ground side). ), superimpose is turned on.
In other words, if you turn on superimpose, Ys
It becomes possible to superimpose the RGB signal which is switched and controlled by the signal, and when superimpose is set to "off", only external RGB can be monitored by pseudo Ys.

Furthermore, in conjunction with the forced Ys switch 6, the picture control volume VR1 (external RGB
(for internal RGB) and VR2 (for internal RGB) switch 7
has been established. When forced Ys switch 6 is turned on,
The changeover switch 7 is turned on, and the adjusted output of the external RGB picture control volume VR1 is transferred via the changeover switch 7 to the three picture control circuits 3a to 3a provided for external RGB.
3c, which allows contrast (or brightness) adjustment to external RGB inputs.

When the forced Ys switch is turned off, superimpose is turned on and the selector switch 7 is turned off, and the output of the picture control volume VR2 provided for internal RGB is changed to the picture control of the Y/C processor IC5. (PIC)
the picture control circuits 3a to 3c via the changeover switch 7.
It is also given to

In other words, when superimposing, internal RGB
External RGB contrast adjustment is also performed in conjunction with the contrast adjustment.

Also, when monitoring only internal RGB,
That is, when using only the internal RGB signal with superimpose turned off and the forced Ys switch 6 turned off, adjust the picture control volume VR2 mentioned above and change the output to Y/C.
Internal RGB contrast can be adjusted by applying it to the picture control terminal of processor IC5.

In this way, the contrast can be adjusted independently for internal RGB and external RGB using dedicated picture control volumes R1 and R2, so compared to the case where shared adjustment volumes are provided, it is easier to change the contrast between internal and external RGB. There is no need to worry about having to adjust the contrast for each image. Moreover, when superimposing internal and external signals, one (in this case, internal) picture control volume VR2 can be used to simultaneously control both internal and external signals, so there is no need for troublesome adjustment operations in this case either. I can't find it.

Note that it may be the control volume VR1 (for external use) that is to be shared during superimposition.

[Effects of the Invention] As described above, the present invention is provided with a switch that forcibly sets the control signal Ys to an external logic level, so it is possible to monitor external RGB signals from video equipment that does not output control signals. Become.

In addition, since the brightness of external signals and internal signals can be controlled independently of each other, there is no need to re-adjust the brightness when switching between internal and external signals. During superimposition, the brightness can be controlled simultaneously and proportionally for both signals with a single brightness adjustment, making it possible to create a television receiver that is extremely easy to operate.

[Brief explanation of the drawing]

The drawing is a circuit diagram of a switching circuit for internal RGB signals and external RGB signals of a television receiver showing an embodiment of the present invention. In addition, in the codes used in the drawings, 1...RGB
Connector, 1a-1c...RGB input terminal, 1d
...Control signal Ys input terminal, 2...Switching circuit, 3a to 3c...Picture control circuit, 4a to 4c...Switch switch, 5...Video Y/C processor IC, 6...Forced YS switch,
7...This is a changeover switch.

Claims (1)

[Claims] 1 Contains an input terminal for the control signal Ys for switching the RGB signal from an internal signal to an external signal.
A switch that forces the RGB input terminal group, the input terminal of the control signal Ys to an external logic level, mutually independent control means that controls the brightness of each of the internal and external signals, and and a signal changeover switch that cuts off the control signal of one of the control means in conjunction with this, and controls the brightness of both the internal signal and the external signal using the control signal of the other control means. A television receiver with terminals.