JPH10191199A - Image output controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image output controller in which a defect of causing difficulty in viewing a video image on a slave screen resulting from the slave screen receiving the effect of automatic brightness limiter(ABL) processing conducted for a master screen when a picture in picture(PINP) function is active, and high image quality is maintained for both images on the master and slave screens in the PINP. SOLUTION: A slave screen use signal processing section 102 uses as inverse ABL processing section 123 to apply processing of an inverse characteristic to an automatic luminance limit processing applied by an ABL signal processing section 106 and video signals are synthesized based on a luminance signal and the ABL signal processing section 106 applies automatic luminance limit processing to cancel the automatic luminance limit processing as to the slave screen as if the automatic luminance limit processing were applied only to the master screen apparently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a PINP (Picture)
The present invention relates to an image output control device having an IN Picture (IN Picture) function, and particularly to an automatic brightness limit (ABL) performed on a main screen when a PINP function is operated.
mitter) Image output control that can output a high-definition image for both the parent screen and the child screen in PINP by eliminating the problem that the image of the child screen becomes difficult to see due to the influence of the processing by the circuit. Related to the device.

[0002]

2. Description of the Related Art One of the functions of a conventional image output apparatus such as a TV is a screen division by a parent (main) screen and a child (sub) screen, which is a so-called PINP function. FIG. 4 shows a configuration diagram of an image output control device for realizing the PINP function.

[0003] In FIG. 4, a conventional image output control device includes a main screen signal processing unit 101 and a small screen signal processing unit 1.
02a, a compression processing unit 103a, a switching unit 104a, a synthesis unit 105, an RGB signal processing unit 106, and a filter 107.

The main screen signal processing section 101 includes a luminance signal processing section 111 for generating a main screen luminance signal Yp and a color signal processing section 112 for generating a main screen color signal U / Vp. I have. On the other hand, the small-screen signal processing unit 102a
Luminance signal processing unit 12 that generates luminance signal Yc for a small screen
1 and a color signal processing unit 122 for generating a color signal U / Vc for a child screen.

[0005] Luminance signal Yc and color signal U / V for child screen
c is subjected to compression processing by the compression processing unit 103a, and the compressed luminance signal Yd and color signal U / Vd are output from the compression processing unit 103a in accordance with the synchronization signal of the main screen,
The signal is input to the switching unit 104a.

In the switching section 104a, the luminance signal Yp and the chrominance signal U / Vp for the main screen and the luminance signal Yp for the child screen which have been subjected to the compression processing based on the PINP switching control signal PIPSW.
d and the color signal U / Vd are switched to output the luminance signal Y and the color signal U / V. Luminance signal Y and color signal U
/ V is converted by the synthesizing unit 105 into the R, G, B video signal YCM
After being synthesized as “a” and further processed by the RGB signal processing unit 106, the video signal PCTa to be supplied to the CRT 150 is output.

Further, the RGB signal processing unit 106
When an L circuit is included and the luminance becomes abnormally high, a large anode current flows to the CRT 150 to overload the high voltage circuit and prevent the horizontal output transistor and the like from being destroyed. Therefore, flyback transformer FB
The signal ABL_IN from T passes through the filter 107 to R
It is supplied to the GB signal processing unit 106. That is, ABL
The circuit detects a change in the current of the flyback transformer FBT and feeds it back to the video amplifier circuit,
The beam current is limited by lowering the average level of the video signal.

[0008]

However, in the above-described conventional image output control device, when the PINP function is operating, the RGB signal processing unit 106 controls the luminance signal Yp and the color signal U / Vp for the main screen. And the ABL circuit is performed as a process after switching between the compressed luminance signal Yd and color signal U / Vd for the child screen, so that not only the video signal of the main screen but also the video of the child screen The signal is similarly processed by the ABL circuit.

The ABL circuit operates with respect to the brightness of the image on the main screen having a large area on which the image is projected. Therefore, when the main screen is bright and the child screen is dark, the ABL circuit is operated. In addition, since the parent screen operates so as to become darker and the child screen operates so as to become darker, the child screen becomes difficult to see. Conversely, if the parent screen is dark and the child screen is a bright image, the ABL circuit operates so that the parent screen becomes brighter and the child screen becomes brighter. There was a situation where the child screen became difficult to see brightly.

The present invention has been made in view of the above-mentioned conventional circumstances, and when a PINP function is activated, a child screen receives an influence of an ABL process performed on a parent screen, and the child screen is affected. It is an object of the present invention to provide an image output control device which can solve the problem that the video becomes difficult to see and can maintain high quality for both the parent screen and the child screen video in PINP.

[0011]

In order to solve the above-mentioned problems, an image output control device according to the present invention is an image output control device having a screen division function of a main screen and a sub-screen, at least for a main screen. A signal processing unit for a main screen that performs processing of a luminance signal of the child screen, a signal processing unit for a child screen that performs processing of a luminance signal for at least a child screen, and the signal processing unit for the parent screen and the signal processing unit for the child screen. A switching unit for switching each output; a current detection unit for detecting a current flowing through a high-voltage winding of a flyback transformer of a CRT; and an automatic brightness limiting process for an output of the switching unit based on a detection result by the current detection unit. And an ABL signal processing unit for performing the following. The small-screen signal processing unit has a characteristic opposite to that of the automatic brightness limiting process based on the detection result by the current detection unit with respect to the small-screen brightness signal. Those having a reverse ABL processing unit supplied to the switching unit performs the process.

An image output control device according to the present invention is an image output control device having a function of dividing a screen into a main screen and a sub-screen. A signal processing unit, a small-screen signal processing unit that performs processing of a luminance signal and a color signal for a small screen, and a switching unit that switches respective outputs of the main-screen signal processing unit and the small-screen signal processing unit. A current detecting means for detecting a current flowing through a high-voltage winding of a flyback transformer of a CRT; An ABL signal processing unit for performing a limiting process, wherein the small-screen signal processing unit has a characteristic opposite to that of the automatic brightness limiting process with respect to the brightness signal for the small screen based on a detection result by the current detection unit. Those having a reverse ABL processing unit supplied to the switching unit performs a sense.

In the image output control device according to the present invention, in the signal processing section for the small screen, the inverse ABL processing section performs processing having characteristics opposite to those of the automatic luminance limiting processing performed in the ABL signal processing section. After the video signal is synthesized based on the ABL signal processing, the ABL signal processing unit performs an automatic brightness limiting process, thereby canceling the automatic brightness limiting process for the child screen, and apparently performing the automatic brightness limiting process only for the parent screen. As if it had been applied. This solves the problem that the child screen is affected by the automatic luminance limiting process performed on the parent screen, making it difficult to see the image of the child screen. An image output control device capable of maintaining high quality can be provided.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image output control device according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram of an image output control device according to an embodiment of the present invention. In the figure,
Portions that overlap with FIG. 4 (conventional example) are given the same reference numerals. The image output control device according to the present embodiment has a PINP function as shown in FIG. 2, that is, a screen division function using a parent (main) screen 151 and a child (sub) screen 152.

In FIG. 1, an image output control device according to the present embodiment includes a signal processing unit 101 for a main screen, a signal processing unit 102 for a small screen, a compression processing unit 103, a switching unit 104, and a synthesizing unit 1.
05, an RGB signal processing unit (ABL signal processing unit) 106 and a filter 107.

The main screen signal processing section 101 includes a luminance signal processing section 111 for generating a main screen luminance signal Yp and a color signal processing section 112 for generating a main screen color signal U / Vp. I have. On the other hand, the small-screen signal processing unit 102 includes a luminance signal processing unit 121 that generates a small-screen luminance signal Yc.
A color signal processing unit 122 for generating a color signal U / Vc for a small screen; and a luminance signal Yd compressed by the compression processing unit 103.
And an inverse ABL processing unit 123 for performing processing with characteristics opposite to those of the ABL processing performed by the RGB signal processing unit 106 based on the ABL control signal ABLC.

The luminance signal Yc and the color signal U / V for the child screen
c are respectively compressed by the compression processing unit 103,
The compressed luminance signal Yd and color signal U / Vd are output from the compression processing unit 103 in synchronization with the synchronization signal of the main screen. The luminance signal Yi subjected to the above processing and the color signal U / Vd subjected to the compression processing for the chrominance signal are input to the switching unit 104 as they are.

In the switching section 104, based on the PINP switching control signal PIPSW, the luminance signal Yp and the chrominance signal U / Vp for the main screen and the luminance signal Y after inverse ABL processing for the child screen are displayed.
i and the compressed color signal U / Vd are switched, and the luminance signal Y and the color signal U / V are output. The luminance signal Y and the color signal U / V are converted into R, G,
B is synthesized as a video signal YCM containing
After being processed by the signal processing unit 106, the CRT 15
The video signal PCT to be supplied to 0 is output.

Further, the RGB signal processing unit 106
When an L circuit is included and the luminance of the screen becomes abnormally high, an excessive anode current Ia flows through the CRT 150, so that the high voltage power supply circuit 200 is overloaded.
High voltage components such as horizontal output transistors are prevented from being destroyed. Therefore, the signal ABL_IN from the flyback transformer FBT is supplied to the RGB signal processing unit 106 via the filter 107.

Generally, as shown in FIG. 3, an ABL circuit is a flyback transformer FB in a high voltage power supply circuit 200.
The current flowing through the high-voltage winding of T is detected, and this current is negatively fed back to the luminance adjustment circuit in the RGB signal processing unit 106 by the signal ABL_IN, thereby lowering the average level of the video signal and causing the anode current Ia to reach the specified value. It is restricted so that it does not become above.

As in the prior art, in the RGB signal processing unit 106, the luminance signal Yp and the color signal U / Vp for the main screen are used.
Is switched between the luminance signal Yd and the color signal U / Vd for the child screen which have been subjected to the compression processing, and are synthesized with the video signal.
When the processing by the L circuit is performed, in the case of PINP, A
The BL circuit is a main screen 15 having a large area on which an image is projected.
Because it operates on the brightness of the image of
When the image 51 is bright and the child screen 152 is dark, on the other hand, the parent screen 151 is darkened and the child screen 152 is operated to be darker, so that the child screen 152 becomes difficult to see.

In the image output control device of this embodiment, the inverse ABL processing unit 123 applies the luminance signal Yd from the luminance signal processing unit 121 and the compression processing unit 103 for the small screen to the inverse ABL processing unit 123.
Processing having control characteristics opposite to the ABL processing performed in the RGB signal processing unit 106 is performed. That is, the luminance signal of the child screen to be supplied to the switching unit 104 is subjected to ABL processing having characteristics reverse to those of the ABL processing performed in the RGB signal processing unit 106 in advance, and an image is displayed based on the luminance signal. After combining the signals, R
By performing the ABL processing by the GB signal processing unit 106, the ABL processing operation for the child screen 152 is canceled, and apparently the AB processing is performed only for the parent screen 151.
L processing is performed.

As described above, according to the image output control device of the present embodiment, there is a problem that the child screen 152 is affected by the ABL processing performed on the parent screen 151 and the image on the child screen 152 becomes difficult to see. As a result, high quality can be maintained for both the parent screen 151 and the child screen 152 in PINP.

[0025]

As described above, according to the image output control apparatus of the present invention, the automatic brightness limiting process for the child screen is canceled, and the automatic brightness limiting process is applied only to the apparently parent screen. In this way, the problem that the child screen is affected by the automatic brightness limiting process performed on the parent screen and the video of the child screen becomes difficult to see is resolved, and both the parent screen and the child screen in the screen division are resolved. High quality video can be maintained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an image output control device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a PINP function on a CRT.

FIG. 3 is a diagram illustrating an automatic brightness limitation (AB) in an image output control device.
L) It is explanatory drawing explaining a processing operation.

FIG. 4 is a configuration diagram of a conventional image output control device that realizes a PINP function.

[Explanation of symbols]

101: Signal processing unit for parent screen, 102, 102a: Signal processing unit for child screen, 103, 103a: Compression processing unit, 10
4, 104a: switching unit, 105: combining unit, 106: RG
B signal processing unit (ABL signal processing unit), 107: filter, 111: luminance signal processing unit for parent screen, 112: color signal processing unit for parent screen, 121: luminance signal processing unit for child screen, 1
22: color signal processing unit for small screen, 123: inverse ABL processing unit, Yp: luminance signal for main screen, U / Vp: color signal for main screen, Yc: luminance signal for small screen, U / Vc ... Color signal for child screen, Yd: compressed luminance signal for child screen, U
/ Vd: compressed color signal for child screen, Yi: inverse ABL
The processed luminance signal for the child screen, PIPSW PINP switching control signal, Y luminance signal, U / V color signal, YCM,
YCMa: video signal, ABL_IN: ABL control signal,
PCT, PCTa: video signal processed by RGB signal processing, A
BLC ABL control signal, 150 CRT, 151 parent screen, 152 child screen, 200 high voltage power supply circuit, FBT
... Flyback transformer, Ia ... Anode current, Ho ...
Horizontal output, Tr: transistor, D1: diode, V
dd: Power supply potential.

Claims (2)

[Claims] 1. An image output control device having a screen division function of a main screen and a sub-screen, comprising: a main screen signal processing unit for processing at least a main screen luminance signal; and at least a sub-screen luminance. A signal processing unit for a small screen for processing a signal; a switching unit for switching respective outputs of the signal processing unit for the main screen and the signal processing unit for the small screen; and a current flowing through a high voltage winding of a flyback transformer of a CRT. A current detection unit for detecting, and an ABL signal processing unit for performing an automatic luminance limiting process on an output of the switching unit based on a detection result by the current detection unit; An image output control having an inverse ABL processing unit for performing a process of a characteristic opposite to the automatic luminance limiting process on the luminance signal for the screen based on the detection result by the current detecting unit and supplying the same to the switching unit apparatus. 2. An image output control device having a screen division function based on a main screen and a sub-screen, comprising: a main screen signal processor for processing a luminance signal and a color signal for the main screen; A signal processing unit for a small screen for processing a luminance signal and a color signal; a switching unit for switching the output of the signal processing unit for the main screen and the signal processing unit for the small screen; and a high voltage winding of a flyback transformer of a CRT A current detecting means for detecting a current flowing through the ABL signal processing section for performing an automatic brightness limiting process on a combined signal of a luminance signal and a color signal output from the switching section based on a detection result by the current detecting means. The small-screen signal processing unit performs a process on the luminance signal for the small screen with a characteristic opposite to that of the automatic luminance limiting process based on the detection result by the current detection unit, and provides the switching unit with Supply An image output control device having an inverse ABL processing unit.