JPH1079899A - Television image receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the television image receiver which enables an on-screen display to be viewed securely, even when a video signal and an on-screen display signal are put together before image adjustments. SOLUTION: A composting circuit 7 which puts the video signal and on-screen signal together is provided in front of an RGB matrix and an adjusting circuit 12 which adjust image quality. For a display and teletext generating circuit 8, an on-screen display control circuit 9 is provided which adjusts the lightness and contrast of the on-screen signal. When the image quality is adjusted according to the control signal from a controller 10, an on-screen display control circuit 9 adjusts the on-screen display signal, so that the on-screen display is not affected by the image quality adjustment. Consequently, the on-screen display changes neither in lightness nor color, even at the time of the image quality adjustment and the on-screen display can be viewed clearly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television receiver, and more particularly, to an on-screen display in a liquid crystal projection television receiver.

[0002]

2. Description of the Related Art In a television receiver having an on-screen display function, various operation states and setting states are displayed on a screen together with images. FIG. 4 shows an example of a conventional television receiver having an on-screen display function.

In FIG. 4, a television broadcast signal is received by an antenna 101. The reception output of the antenna 101 is supplied to a tuner circuit 102. A signal of a desired channel is selected from the received signals by the tuner circuit 102, and the received signal is converted into a predetermined intermediate frequency signal. The output of the tuner circuit 102 is supplied to the intermediate frequency circuit 103. The intermediate color circuit 103 demodulates the composite color video signal.

An output of the intermediate frequency circuit 103 is supplied to an input terminal 104A of a switch circuit 104. The video signal from the external video input terminal 105 is supplied to the input terminal 104B of the switch circuit 104. The switch circuit 104 selects a video signal based on the received television broadcast and a video signal from the external video input terminal 105.

The output of the switch circuit 104 is supplied to a video signal processing circuit 106. The luminance signal Y and the chroma signal C are separated from the composite color video signal from the switch circuit 104 by the video signal processing circuit 106, and the color difference signals RY and BY are demodulated from the chroma signal C. Then, from the luminance signal Y and the color difference signals RY and BY,
Three primary color signals R, G, B are formed.

The output of the controller 110 is supplied to the video signal processing circuit 106. With the output of the controller 110, image quality adjustment such as picture (contrast), brightness (brightness), color (color density), hue (hue), sharpness (outline emphasis) is performed.

The output of the video signal processing circuit 106 is supplied to a synthesizing circuit 107. The synthesis circuit 107 is supplied with an on-screen display signal from the display generation circuit 108. The display generation circuit 108 generates an on-screen display signal based on a control signal from the controller 110. The display signal from the display generation circuit 108 is combined with the video signal from the video signal processing circuit 106 by the synthesis circuit 107. The output of the synthesizing circuit 107 is supplied to a CRT picture tube 109.

As described above, in a television receiver provided with an on-screen display function, the display generation circuit 108
The display generation circuit 108 generates an on-screen display signal for displaying various operation states and setting states on a screen. The synthesizing circuit 107 synthesizes the on-screen signal with the video signal, and displays various operation states and setting states on the screen.

[0009] By the way, in the above-mentioned television receiver, the CRT picture tube 109 is used. In addition to the television receiver using the CRT picture tube,
2. Related Art A liquid crystal projection television receiver that projects a screen on a screen using a liquid crystal projector is known. Such a liquid crystal projection television receiver also has the above-described on-screen display function, and various operation states and setting states are displayed on the screen.

FIG. 5 shows a configuration of a conventional liquid crystal projection television receiver provided with an on-screen display function. In FIG. 5, the antenna 151
Receives a television broadcast signal through the antenna 15
1 is supplied to the tuner circuit 152. A signal of a desired channel is selected from the received signals by the tuner circuit 152, and the selected received signal is converted into a predetermined intermediate frequency signal. The output of the tuner circuit 152 is supplied to the intermediate frequency circuit 153. Intermediate frequency circuit 1
At 53, the composite color video signal is demodulated. This video signal is supplied to the input terminal 154A of the switch circuit 154.

[0011] The television receiver is provided with an external video input terminal 155. The video signal from the external video input terminal 155 is supplied to the terminal 154B of the switch circuit 154.

[0012] The switching circuit 154 selects a video signal based on the received television broadcast and a video signal from the external video input terminal 155. The output of the switch circuit 154 is supplied to a chroma decoder 156.

The chroma decoder 156 separates the video signal into a luminance signal Y and a chroma signal C, and demodulates the color difference signals RY and BY from the chroma signal C to form a component color video signal. is there. Chroma decoder 15
6 is supplied to the synthesis circuit 157.

The display signal from the display and teletext generating circuit 158 is supplied to the synthesizing circuit 157. The display and teletext generation circuit 158 includes a controller 160
Generates an on-screen display signal and a teletext signal on the basis of the control signal.

The output of the synthesizing circuit 157 is the scanning number converting circuit 1
61. The scanning number conversion circuit 161 converts the number of scanning lines so that the number of scanning lines in one field is 480 and the non-interlace method is used.

The output of the scanning line number conversion circuit 161 is supplied to an RGB matrix and video adjustment circuit 162. RGB
The matrix and image adjustment circuit 162 forms three primary color signals RGB, and under the control of the controller 160, adjusts image quality such as picture, brightness, color, hue, and sharpness. The output of the RGB matrix and video adjustment circuit 162 is supplied to the display drive circuit 163.

As described above, in the liquid crystal projection television receiver, the scanning number conversion circuit 161 is provided. That is, in the liquid crystal projection television receiver, the number of scanning lines is 480. The liquid crystal projector is of a non-interlaced type because the luminance is insufficient compared with the CRT picture tube. On the other hand, for example, in the NTSC system, the number of effective scanning lines in one field is 240 in the interlace system. In the PAL system and the SECAM system, the number of effective scanning lines in one field is 288 in the interlace system. For this reason, a liquid crystal projection television receiver receives a non-interlaced signal from a signal having 240 effective scanning lines per field in an interlaced system or a signal having 288 effective scanning lines per field in an interlaced system. Scan line conversion circuit 16 which converts the number of effective scan lines in one field into 480 signals
1 is provided.

The display and teletext generation circuit 158
An on-screen display signal and a teletext signal are generated based on a control signal from the controller 160. Therefore, the display and teletext generation circuit 15
The conversion of the number of scanning lines is also required for the on-screen display signal from 8. Therefore, in the case of such a liquid crystal projection television receiver that involves the conversion of the number of scanning lines, it is necessary to provide the synthesizing circuit 157 of the on-screen display signal and the video signal before the scanning line converting circuit 161.

The scanning line number conversion circuit 161 digitizes the signal of each line to form an interpolation line.
It has a D conversion circuit and a D / A conversion circuit, and has a limited dynamic range. When the image quality is adjusted by user control, the amplitude and the DC level of the video signal greatly change. Therefore, if a scanning line number conversion circuit is provided after the image quality adjustment circuit, the dynamic range cannot be satisfied. For this reason, in the case of a liquid crystal projection television receiver with such conversion of the number of scanning lines,
It is necessary to provide a circuit for adjusting the image quality (RGB matrix and video adjustment circuit 162) at the subsequent stage of the scanning line number conversion circuit 161.

Therefore, in the case of a liquid crystal projection television receiver having such a conversion of the number of scanning lines, a synthesizing circuit 1 for combining an on-screen display signal and a video signal.
It is necessary to provide an RGB matrix 57 and a video adjustment circuit 162 at a stage subsequent to the scanning line conversion circuit 161, and a synthesis circuit 157 for combining the on-screen display signal and the video signal with the video signal for adjusting the video signal. Circuit (RG
It is provided before the B matrix and image adjustment circuit 162).

[0021]

However, if the synthesizing circuit 157 of the on-screen display signal and the video signal is provided before the circuit for adjusting the video signal (RGB matrix and video adjusting circuit 162), the on-screen When adjusting the image quality while checking the image quality setting status displayed by the display function, the display by the on-screen display changes according to the image quality adjustment status, and the on-screen display becomes difficult to see. is there.

That is, for example, when adjusting the brightness, when the image quality is made brighter or darker, the picture becomes brighter or darker, and the on-screen display for brightness becomes brighter. Or darkens. For this reason, when adjusting the brightness while watching the on-screen display of the brightness setting, the on-screen display may be too bright to be seen or may be too dark to be seen. Furthermore, if the power is turned off while the brightness adjustment is too bright or too dark to make the on-screen display difficult to see, the next time the power is turned on, nothing will appear on the screen, May be mistaken.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a television receiver capable of reliably recognizing an on-screen display even when a video signal and an on-screen display signal are synthesized before image adjustment. To provide.

[0024]

SUMMARY OF THE INVENTION The present invention provides a display signal generating means for generating a display signal for displaying various setting states on a screen, a synthesizing means for synthesizing a video signal and a display signal, and a display. Image quality adjusting means for adjusting the image quality of the video signal synthesized with the signal, display signal adjusting means for adjusting the display signal generated from the display signal generating means, and image quality adjustment and display signal adjustment of the video signal by the image quality adjusting means Control means for controlling the adjustment of the display signal by the means, wherein the control means controls the display signal so as to compensate the adjustment amount of the video signal when adjusting the video signal. TV receiver.

When the image quality is adjusted based on the control signal from the controller, the on-screen display signal is adjusted so as to compensate the image quality adjustment so that the on-screen display is not affected by the image quality adjustment. Thus, even when the image quality is adjusted, the brightness and color of the on-screen display do not change, and the on-screen display can be clearly recognized.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of a liquid crystal projection television receiver to which the present invention is applied.

In FIG. 1, a television broadcast signal is received by an antenna 1, and a reception output of the antenna 1 is supplied to a tuner circuit 2. A signal of a desired channel is selected from the received signals by the tuner circuit 2, and the selected signal is converted into a predetermined intermediate frequency signal. The output of the tuner circuit 2 is supplied to the intermediate frequency circuit 3. The intermediate color circuit 3 demodulates the composite color video signal. This video signal is supplied to the input terminal 4A of the switch circuit 4.

The television receiver is provided with an external video input terminal 5. The video signal from the external video input terminal 5 is supplied to the terminal 4B of the switch circuit 4.

By the switch circuit 4, a video signal based on the received television broadcast and an external video input terminal 5
Is selected. The output of the switch circuit 4 is supplied to a chroma decoder 6.

The chroma decoder 6 separates a video signal into a luminance signal Y and a chroma signal C, and demodulates the color difference signals RY and BY from the chroma signal C. The output of the chroma decoder 6 is supplied to the synthesis circuit 7.

The synthesizing circuit 7 has a display and teletext generating circuit 8 via an on-screen display signal control circuit 9.
Is supplied. The display and teletext generation circuit 8 generates an on-screen display signal and a teletext signal based on a control signal from the controller 10. On-screen display signal control circuit 9
Adjusts the brightness, contrast, color density, etc. of the on-screen display signal and the teletext signal output from the display and teletext generation circuit 8 based on the control signal from the controller 10.

The output of the synthesizing circuit 7 is supplied to the scanning number converting circuit 11. The scanning number conversion circuit 11 converts the number of scanning lines so that the number of scanning lines in one field is 480 and the non-interlace method is used. That is, in the liquid crystal projector, the number of scanning lines is 480 in a non-interlace system. On the other hand, for example, NT
In the SC system, the number of effective scanning lines in one field is 240 in the interlace system. In the PAL system and the SECAM system, the number of effective scanning lines in one field is 288 in the interlace system. The scanning line number conversion circuit 11 converts an image signal of 240 or 288 effective scanning lines in one field in an interlaced system to a video signal of 480 scanning lines in a non-interlaced system so as to correspond to display on a liquid crystal projector. Converted to a signal.

The output of the scanning line number conversion circuit 11 is supplied to an RGB matrix and image adjustment circuit 12. The RGB matrix and image adjustment circuit 12 converts the component signals including the luminance signal Y and the color difference signals RY and BY into
The three primary color signals RGB are formed and the controller 1
Under the control of 0, picture quality adjustment such as picture, brightness, color, hue, and sharpness is performed. The output of the RGB matrix and video adjustment circuit 12 is supplied to the display drive circuit 13.

Since the liquid crystal projection television receiver is provided with the number-of-scanning-lines conversion circuit 11, the synthesizing circuit 7 for synthesizing the video signal, the on-screen display signal and the teletext signal includes an RGB matrix and a video adjustment circuit. It is provided at a stage preceding to twelve. In such a configuration, when the image quality is adjusted by the RGB matrix and image adjustment circuit 12, the on-screen display also changes. For this reason, if the brightness, the picture, and the like are adjusted while watching the on-screen display, the on-screen display also changes accordingly, and the on-screen display may be difficult to see.

Therefore, in the liquid crystal projection television receiver to which the present invention is applied, the controller 10
An on-screen display control circuit 9 for adjusting the on-screen display signal output from the display and teletext generation circuit 8 based on the control signal from the control unit is provided. The on-screen display control circuit 9 adjusts the on-screen display signal to compensate for the image quality adjustment so that the on-screen display is not affected by the image quality adjustment when the image quality adjustment is performed.

That is, when the image quality adjustment mode is set,
A user control menu display as shown in FIG. 2 is displayed. The user control menu display includes an on-screen display 51 indicating a picture setting state, an on-screen display 52 indicating a brightness setting state,
An on-screen display 53 indicating a color setting state, an on-screen display 54 indicating a hue setting state, and an on-screen display 55 indicating a sharpness setting state are included.

Here, when the user adjusts the picture, brightness, color, hue, and sharpness, these adjustment states are indicated by bar graphs on the on-screen displays 51 to 55. At this time, if the signals from the display and teletext generating circuit 8 are used as they are, the contrast, brightness, color density, hue, contour emphasis, etc. of the screen change along with the adjustment of the image quality, and the on-screen display is performed. The brightness and color of 51 to 55 change. For this reason, when adjusting the contrast and brightness while watching the on-screen display of the picture and brightness settings, the on-screen displays 51 to 55 may be too bright or too dark to be seen. possible.

Therefore, when the picture and brightness are adjusted, the contrast and brightness of the on-screen display signal are adjusted so as to compensate for the image quality adjustment of the video signal. Regardless,
The on-screen display is not changed.

For example, FIG. 3 is a flowchart showing the processing at this time. As shown in FIG. 3, it is determined whether a picture or brightness adjustment is performed (step ST1). When the picture or brightness is adjusted, it is determined whether the picture or brightness is to be increased (step ST2) or to be decreased (step ST3). If neither input to increase nor decrease the picture or brightness is given, it is determined whether or not the adjustment is completed (step ST4). If the adjustment is completed, the adjustment process is ended. Returned to ST2.

If it is determined in step ST2 that an input to increase the picture or brightness has been given, the image quality is adjusted by the RGB matrix and image adjustment circuit 12 so as to increase the contrast and brightness (step ST5). Then, the bar graph of the on-screen display 51 of the picture or the on-screen display 52 of the brightness is increased according to the adjustment state of the picture or brightness (step ST6). At this time, the contrast and brightness of the on-screen display signal are reduced by the on-screen display control circuit 9 in accordance with the increase in contrast and brightness by the RGB matrix and image adjustment circuit 12 (step). ST7). For this reason, on the screen, when the picture or brightness is increased, the contrast and brightness of the video portion increase, but the contrast and brightness of the on-screen displays 51 to 55 do not change.

If it is determined in step ST3 that the picture or brightness is to be reduced, the RGB matrix and image adjustment circuit 1 is controlled so that the contrast and brightness are reduced.
Image quality adjustment is performed in step 2 (step ST8). Then, the bar graph of the on-screen display 51 of the picture or the on-screen display 52 of the brightness is reduced according to the adjustment state of the picture or brightness (step ST9). At this time, the contrast and brightness of the on-screen display signal are increased by that amount by the on-screen display signal control circuit 9 in response to the reduction of the contrast and brightness by the RGB matrix and image adjustment circuit 12 (step). ST10). For this reason, on the screen, when the picture or brightness is reduced, the contrast and brightness of the video portion are reduced.
The contrast and brightness of 1 to 55 do not change.

As described above, when the input of the picture or the brightness is increased or decreased and the adjustment is performed, it is determined whether or not the adjustment is completed (step ST).
11) If the adjustment is completed, the picture and brightness adjustment processing is ended. If the adjustment is not completed, the process returns to step ST2.

In the above example, the contrast and brightness of the on-screen signal are adjusted so as to compensate for the image quality adjustment of the video signal when adjusting the picture and brightness. Similar processing may be performed for other adjustment items such as color and hue.

In the above-described example, the liquid crystal projection television receiver has been described. However, the present invention is not limited to the liquid crystal projection television receiver, but may be a television receiver using a CRT tube. The present invention can be similarly applied to a television receiver using a liquid crystal display.

[0045]

According to the present invention, the image quality is adjusted based on the control signal from the controller. When the image quality is adjusted, the image quality is adjusted so that the on-screen display is not affected by the image quality adjustment. The on-screen display signal is adjusted to compensate. Thus, even when the image quality is adjusted, the brightness and color of the on-screen display do not change, and the on-screen display can be clearly recognized.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a television receiver to which the present invention has been applied.

FIG. 2 is a schematic diagram used for describing on-screen display in a television receiver to which the present invention has been applied.

FIG. 3 is a flowchart used to explain on-screen display in a television receiver to which the present invention is applied.

FIG. 4 is a block diagram illustrating an example of a configuration of a conventional television receiver.

FIG. 5 is a block diagram illustrating another example of the configuration of a conventional television receiver.

[Explanation of symbols]

7 ... Synthesis circuit, 8 ... Display and teletext generation circuit, 9 ... On-screen display control circuit, 10 ...
.Controller, 12 ... RGB matrix and video adjustment circuit

Claims (4)

[Claims] 1. A display signal generating means for generating a display signal for displaying various setting states on a screen, a synthesizing means for synthesizing a video signal and the display signal, and an image in which the display signal is synthesized Image quality adjustment means for adjusting the image quality of the signal; display signal adjustment means for adjusting the display signal generated from the display signal generation means; image quality adjustment of the video signal by the image quality adjustment means and display by the display signal adjustment means Control means for controlling signal adjustment, wherein the control means controls the display signal so as to compensate for the adjustment amount of the video signal when adjusting the video signal. Television receiver. 2. The television receiver according to claim 1, wherein the image quality adjustment is a brightness adjustment. 3. The television receiver according to claim 1, wherein the image quality adjustment is a picture adjustment. 4. The television receiver according to claim 1, wherein the image quality adjustment is a color adjustment.