KR19990043032A - Automatic adjustment of sub-screen brightness according to main screen brightness of television receiver - Google Patents

Abstract

Recently, a television receiver equipped with a picture in picture which enables a viewer to simultaneously watch a plurality of broadcast channels through a CRT has been developed and spread. However, in such a television receiver, since the main screen and the sub-screen are generated on one CRT screen and the sub-screen is usually set smaller in size than the main screen, the screen brightness of the main screen and the sub-screen is set to be the same. In this case, the viewer may not be able to clearly recognize the main screen and the sub-screen.

In the present invention, screen brightness detecting means 31 for detecting the brightness of the main screen based on the beam current flowing through the CRT, and adjustment data for adjusting the screen brightness of the sub-screen in inverse proportion to the screen brightness of the main screen. A sub picture adjustment data memory 32 is provided. Then, the microprocessor 33 reads the sub-screen adjustment data from the sub-screen adjustment data memory 32 on the basis of the screen brightness data detected by the screen brightness detecting means 31 and based on the sub-screen processing unit ( 8).

Therefore, in the present invention, since the screen brightness of the sub-screen is automatically adjusted in inverse proportion to the screen brightness of the main screen, the viewer clearly recognizes the main screen and the sub-screen, thereby improving the viewing efficiency.

Description

Automatic adjustment of sub-screen brightness according to main screen brightness of television receiver

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television receiver having a picture in picture (PIP) output function, and in particular, a television receiver capable of providing an optimal viewing environment by automatically adjusting the brightness of the subscreen according to the brightness of the main screen. It relates to a device for automatically adjusting the sub-screen brightness according to the main screen brightness.

In recent years, with the development of signal processing technology, television receivers with sub-screen functions that allow two or more broadcast screens to be viewed through a single CRT (Cathode-ray Tube) have been developed and put into practical use.

1 is a block diagram showing the configuration of a television receiver having a conventional general sub-screen function.

In FIG. 1, reference numeral 1 denotes an antenna, 2 denotes a first tuner which executes a broadcasting station for a main screen under control of the microprocessor 14, and 3 denotes an output of the first tuner 2. A first IF processor for performing amplification processing and separation of video and audio intermediate frequencies for the intermediate frequency IF, 4 detects the intermediate frequency output from the first IF processor 3, and outputs a composite video signal; It is a first image detector.

In addition, reference numeral 5 denotes a second tuner for executing a broadcast station for sub-pictures under the control of the microprocessor 14, and 6 denotes a second tuner for processing the intermediate frequency IF output from the second tuner 5; IF processor, 7 is a second image detector for detecting the intermediate frequency output from the second IF processor 6 and outputs a composite video signal, 8 is the second image detector under the control of the microprocessor 14 The composite video signal outputted from (7) is processed to output the R (Red), G (Green), B (Blue) signal and the sub picture blanking signal P corresponding to the video signal, and the microprocessor 8 Is a sub-screen processing unit which executes luminance and color tone processing for the sub-screen according to the control of the "

In the drawing, reference numeral 9 denotes an image to be output to the CRT based on the composite image signal output from the first image detector 4 and the RGB and sub-screen blanking signals P output from the sub-screen processing unit 8. An image processor which outputs an RGB signal corresponding to the screen and performs luminance and color tone processing of the image screen under the control of the microprocessor 14, 10 based on the RGB signal output from the image processor 9; CRT driving unit for driving the CRT.

In the drawing, reference numeral 11 denotes a remote controller for the viewer to operate the television receiver, and 12 denotes a receiver for converting an infrared signal applied from the remote controller 11 into an electrical code signal corresponding thereto. A data memory in which various control data for controlling the first and second tuners 2 and 5, the image processing unit 9 and the sub-screen processing unit 14 are stored, and 14 is an infrared ray applied from the remote controller 11 It is a microprocessor that controls the entire device according to the signal.

That is, in the above-described configuration, when the viewer controls the remote controller 11 to select the sub picture function, the microprocessor 14 drives the sub picture processing unit 8 to tune to the second tuner 5. RGB and sub-screen blanking signals P corresponding to channel broadcasting are input to the image processor 9.

In addition, the image processor 9 may apply an RGB signal for the main screen, that is, an image signal detected by the first image detector 4 based on the sub-screen blanking signal P applied by the sub-screen processor 8. The corresponding RGB signal and the RGB signal output from the sub picture processor 8 are switched and selectively output to the CRT driver 10 to generate a main picture and a sub picture on the CRT. In this case, the broadcast channel for the main picture and the sub picture is selected by the microprocessor 14 controlling the first and second tuners 2 and 5 according to a selection signal from the remote controller 11.

By the way, the following problem exists in the apparatus mentioned above.

FIG. 2 shows an example of an output screen generated on a CRT by a television receiver having a sub-screen function as described above. As shown in FIG. 2, the sub-screen is set smaller in size than the main screen. It is located in a certain area. Of course, in this case, the position of the sub picture is not limited to a specific area, but the area is set to be surrounded by the normal main screen.

Therefore, in FIG. 2, if the brightness of the video screen output through the main screen is very dark, a dark video screen is output through the sub-screen, or conversely, both the main screen and the sub-screen video screen are bright It becomes very difficult for the viewer to recognize the sub-screen.

Of course, the brightness of the main screen and the sub-screen may be changed by the microprocessor 14 controlling the image processor 9 and the sub-screen processor 8 in FIG. 1. That is, the microprocessor 14 controls the image processor 9 and the sub-screen processor 8 based on the control data stored in the data memory 13 to set the brightness of the main screen and the sub-screen. In this case, the control data for the main screen stored in the data memory 13 can be changed by the viewer by operating the remote controller 11.

Therefore, when the brightness level of the main screen and the sub-screen is the same as described above, the viewer can increase the viewing efficiency by changing the brightness of the main screen by operating the remote controller 11, this is executed through the main screen control Therefore, in addition to lowering the viewing efficiency of the main screen, which is the main viewing target, it is also practically impossible for the viewer to adjust the brightness of the output screen in response to the constantly changing screen state.

Accordingly, the present invention has been made in view of the above circumstances, and according to the main screen brightness of the television receiver to increase the viewer's viewing efficiency by automatically adjusting the screen brightness of the sub-screen corresponding to the screen brightness of the main screen. An object of the present invention is to provide a device for automatically adjusting sub-screen brightness.

1 is a block diagram showing a general configuration of a television receiver having a sub picture function.

2 is a diagram illustrating the shapes of a main screen and a sub-screen appearing on a CRT.

3 is a block diagram illustrating an apparatus for automatically adjusting sub-screen brightness according to main screen brightness of a television receiver according to an embodiment of the present invention.

FIG. 4 is a diagram illustrating the configuration of the CRT driver 10 and the screen brightness detector 31 in FIG. 3.

FIG. 5 is an operation flowchart for explaining the operation of the apparatus shown in FIG. 3; FIG.

**** Brief description of the main parts of the drawing ****

1: antenna, 2, 5: tuner,

3, 6: IF processor, 4, 7: image detector,

8: sub-screen processing unit, 9: image processing unit,

10: CRT drive unit, 31: screen brightness detection unit,

32: sub-screen adjustment data memory, 33: microprocessor,

41: anode terminal, 311: analog-to-digital converter.

The apparatus for automatically adjusting the sub-screen brightness according to the main screen brightness of the television receiver according to the present invention for realizing the above object includes a first tuner for tuning a channel broadcast for the main screen, and a channel broadcast for the sub-screen. A second tuner, a sub picture processor which generates and outputs a video signal for generating a sub picture based on a broadcast signal of channel broadcast tuned by the second tuner, and a broadcast signal of channel broadcast tuned by the first tuner; And an image processor for outputting a video signal for generating a main screen and a sub-screen on a CRT based on the sub-screen video signal inputted from the sub-screen processor, and based on the video signal output from the video processor. A television receiver having a CRT driving unit for driving a CRT, comprising: a video screen output on a CRT based on an amount of empty current flowing through the CRT; A sub-screen adjustment data memory which stores a screen brightness detector for outputting screen brightness data corresponding to the screen brightness, and adjustment data for controlling screen brightness of the sub-screen corresponding to the screen brightness of the main screen output on the CRT; And a microprocessor configured to read the sub-screen brightness adjustment data from the sub-screen adjustment data memory based on the screen brightness data input from the screen brightness detector, and to control the sub-screen processing unit based on the read adjustment data. Characterized in that configured.

According to the present invention having the above-described configuration, the brightness of the subscreen is automatically appropriately set according to the brightness of the main screen. Therefore, since the viewer can easily recognize the sub-screen output to the CRT, the viewing efficiency of the viewer is increased.

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings.

3 is a block diagram illustrating an apparatus for automatically adjusting sub-screen brightness according to main screen brightness of a television receiver according to an embodiment of the present invention. Description is omitted.

In FIG. 3, reference numeral 31 denotes a screen brightness detector for detecting brightness of an image screen generated on the CRT based on the amount of beam current flowing through the CRT, and 32 denotes screen brightness of a sub-screen corresponding to the brightness of the main screen. A sub picture adjustment data memory in which control data for controlling the luminance level is stored, which is constituted by, for example, a look-up table. In this case, the look-up table 32 controls to make the screen brightness of the subscreen dark when the screen brightness of the main screen is bright, and to make the screen brightness of the subscreen bright when the screen brightness of the main screen is dark. The data is stored.

In the drawing, reference numeral 33 denotes a microprocessor for controlling the screen brightness of the sub-screen based on the brightness of the main screen. The microprocessor 33 determines the brightness of the main screen on the basis of the detection data detected by the screen brightness detection unit 31, and then, based on the determination result, the sub-screen adjustment data from the sub-screen adjustment data memory 32. The sub screen processor 8 controls the sub screen processor 8 to generate a sub screen having brightness corresponding to the screen brightness of the main screen.

4 is a diagram illustrating the configuration of the CRT driver 10 and the screen brightness detector 31 in FIG. 3. In FIG. 4, for example, a collector of transistors Q1 to Q3 is connected to a 175V power supply voltage V1 through resistors R1 to R3, and the connection node is coupled to a cathode (not shown) of the CRT. RGB signals are respectively coupled to the bases of Q1 to Q3.

The emitters of the transistors Q1 to Q3 are grounded through the resistor R4, and an analog-to-digital converter 311 is coupled to the connection node N1. Here, the analog-to-digital converter 311 inputs data corresponding to the potential of the connection node N1 to the microprocessor 33 of FIG. 3.

In the above configuration, when RGB signals having predetermined levels are respectively applied to the bases of the transistors Q1 to Q3 of the CRT driver 10, the level voltage corresponding to the level of the respective RGB signals is applied to the cathode side of the CRT. Accordingly, an electron beam corresponding to the level of the RGB signal is emitted from the cathode of the CRT to be scanned to the screen side of the CRT. As the beam current flows in the direction opposite to the emission direction of the electron beam, the beam current is transmitted from the flyback transformer (FBT) to the anode terminal 41 of the CRT, the CRT screen, the CRT cathode, and the transistor ( The current flows through the collector-emitter current paths of Q1 to Q3) and the resistor R4 to ground.

Here, when the amount of current flowing through the resistor R4 is referred to as I _R , and the amount of current flowing through the collector-emitter of the transistors Q1 to Q3 is referred to as I1, I2, and I3, respectively, I _R = I1 + I2. In this case, the I _R corresponds to the brightness of the screen generated on the CRT.

That is, in general, the color and brightness of the image screen formed on the CRT is determined according to the electron beam amount according to each RGB signal emitted from the cathode of the CRT, and the amount of beam current is determined in proportion to the electron beam amount. Therefore, the amount of current I _R flowing through the resistor R4 is in proportion to the brightness of the image screen.

On the other hand, the potential of the node N1 of the screen brightness detection unit 31 is represented by I _R · R when the resistance value of the resistor R4 is “R”. Accordingly, the potential of the node N1 is It has a value proportional to the brightness of the video screen scanned on the CRT. The potential value of the node N1 is input to the microprocessor 33 through the analog-digital converter 311.

Next, the control operation of the microprocessor 33 in FIG. 3 will be described with reference to the operation flowchart shown in FIG. 5.

When the viewer selects the sub picture function by using the remote controller 11 after turning on the television receiver (ST1, ST2), the microprocessor 33 controls the sub picture processing unit 8 to display the sub picture on the CRT. Generate (ST3).

Next, the microprocessor 33 detects whether the vertical synchronization signal Vsyn is input (ST4). Here, the vertical synchronization signal Vsyn is output from the image processor 9.

On the other hand, when the vertical synchronization signal Vsyn is input in step ST4, the microprocessor 33 checks whether the sub-screen blanking signal P is output from the sub-screen processing unit 8, and then the sub-screen blanking signal P. ) Is not outputted, the screen brightness data input from the screen brightness detection unit 31 is stored in the internal memory (not shown) (ST5, ST6). In this case, detecting the screen brightness data based on whether the sub-screen blanking signal P is output is to control the brightness of the sub-screen based only on the brightness of the main screen.

Then, the microprocessor 33 repeatedly executes the above-described steps ST5 and ST6 until the next vertical synchronization signal Vsyn is input or the viewer turns off the sub picture function by using the remote controller 11. Screen brightness data is input and stored.

On the other hand, when the vertical synchronization signal Vsyn is input in step ST7, the microprocessor 33 calculates an average screen brightness value by calculating and processing screen brightness data stored in the internal memory until then (ST9). The sub-screen adjustment data storage unit 32 reads the sub-screen adjustment data from the sub-screen adjustment data storage unit 32 based on the calculated average screen brightness value, and then controls the sub-screen processing unit 8 based on the read data. The brightness of the generated sub-screen is controlled (ST10).

Subsequently, the microprocessor 33 resets the screen brightness data stored in the internal memory and proceeds to the above-described step ST5 to continuously execute the above-described sub-screen brightness automatic control function.

That is, in the above embodiment, the average screen brightness of the main screen is calculated by averaging the screen brightness data input during the next vertical sync signal section from one vertical sync signal. In addition, the brightness of the pure main screen is detected by inputting screen brightness data based on the sub-screen blanking signal P. FIG. Then, on the basis of the brightness data of the main screen obtained in this process, the adjustment data for controlling the sub-screen brightness from the sub-screen adjustment data memory 32 is read out. Adjustment data for adjusting the brightness of the sub-screen in inverse proportion to the brightness is stored.

Therefore, in the above embodiment, the brightness of the subscreen is automatically adjusted in inverse proportion to the brightness of the main screen, thereby providing a viewing environment in which the viewer can satisfactorily watch the subscreen.

In addition, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the technical gist of the present invention.

For example, in the above embodiment, the microprocessor 33 detects the average screen brightness of the screen based on the vertical synchronization signal Vsyn. However, the microprocessor 33 detects the average screen brightness based on the horizontal synchronization signal. More precise control operation is possible.

That is, in the NTSC system, in general, the equalization pulse and the horizontal and vertical synchronization pulses are transmitted during the 1H to 21H (H is the horizontal synchronization signal) period, and the video signal is substantially transmitted from 22H. If the 33 counts the horizontal synchronization signal output from the normal image processing unit 9 and inputs screen brightness data from 22H, more precise sub-screen brightness control can be executed. Further, in view of the above circumstances, it may be desirable to perform the operations of steps ST9 to ST11 during the 1H to 21H period in the flowchart shown in FIG.

It is also preferable here to use a vertical blanking signal instead of the vertical synchronizing signal Vsyn.

As described above, according to the present invention, an apparatus for automatically adjusting sub-screen brightness according to the brightness of the main screen of the television receiver, which enables viewers to increase viewing efficiency by automatically adjusting the screen brightness of the sub-screen corresponding to the screen brightness of the main screen. Can be realized.

Claims (6)

A first tuner 2 for tuning channel broadcast for the main picture, a second tuner 5 for tuning channel broadcast for the sub picture, and a broadcast of channel broadcast tuned by the second tuner 2 The sub-screen processing unit 8 generates and outputs an image signal for generating a sub-screen based on the signal, and processes the broadcast signal of channel broadcasting tuned by the first tuner 2 and the sub-screen processing unit 8 A video processor 9 for outputting a video signal for generating a main screen and a sub-screen on a CRT based on the sub-screen video signal input from the sub-screen video signal, and a CRT based on the video signal output from the video processor 9 In the television receiver having a CRT drive unit 9 for driving the A screen brightness detector 31 for outputting screen brightness data corresponding to screen brightness of an image screen output on the CRT based on the amount of empty current flowing through the CRT; A sub-screen adjustment data memory 32 in which adjustment data for controlling screen brightness of the sub-screen is stored corresponding to the screen brightness of the main screen output on the CRT; The sub-screen brightness adjustment data is read from the sub-screen adjustment data memory 32 on the basis of the screen brightness data input from the screen brightness detector 31, and at this time, the sub-screen processing section 8 is based on the read adjustment data. A sub-screen brightness automatic adjustment device according to the main screen brightness of the television receiver, characterized in that it comprises a microprocessor (33) for controlling the. The display apparatus of claim 1, wherein the microprocessor (33) averages screen brightness data for the next vertical synchronization signal section from one vertical synchronization signal, and subscreen brightness from the subscreen adjustment data memory (32) based on the average value. An apparatus for automatically adjusting sub-screen brightness according to the brightness of the main screen of a television receiver, characterized by reading out adjustment data. The display apparatus of claim 1, wherein the microprocessor (33) averages screen brightness data for the next vertical blanking signal section from one vertical blanking signal and sub-screen brightness from the sub-screen adjustment data memory (32) based on the average value. An apparatus for automatically adjusting sub-screen brightness according to the brightness of the main screen of a television receiver, characterized by reading out adjustment data. The main screen brightness of the television receiver according to any one of claims 1 to 3, wherein the microprocessor (33) excludes screen brightness data detected during the output period of the sub-screen blanking signal (P). Sub picture brightness automatic adjustment device. The microprocessor (33) according to any one of claims 1 to 3, wherein the microprocessor (33) excludes screen brightness data detected during a period from 1H to 21H when one horizontal synchronization signal section is 1H. An apparatus for automatically adjusting sub-screen brightness according to the brightness of the main screen of a television receiver. The apparatus for automatically adjusting sub-screen brightness according to the main screen brightness of a television receiver according to claim 1, wherein the sub-screen adjustment data memory 32 stores sub-screen brightness adjustment data in inverse proportion to the brightness of the main screen. .