JP2007334176A - Video display apparatus and television receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the lightness unevenness and color unevenness between the neighborhood of a middle part of the edge of a video display region and the edge while reducing the electric power consumption by a backlight device. <P>SOLUTION: In the liquid crystal display panel for displaying the video based on the an inputted video signal, a video display region where the video is displayed and a non-video display region where the video is not displayed are detected (S2), and a fluorescent tube arranged in a position corresponding to the video display region among a plurality of the fluorescent tubes for illuminating the liquid crystal display panel from the back and the fluorescent tube adjacent to the outer side of the fluorescent tube is made to emit light and the fluorescent tube excluding the above-described fluorescent tube is switched off (S4). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a video display device that displays an input video on a display panel, and more particularly to power saving of a backlight device that illuminates the display panel from behind.

2. Description of the Related Art Conventionally, a video display device provided in a television receiver or the like is a backlight device having a display panel that displays video based on an input video signal and a plurality of fluorescent tubes that illuminate the display panel from behind. And.
In the video display device, the size and position of the video displayed on the display panel can be changed. At this time, by changing the size and position of the video, the display panel displays a video display area (hereinafter referred to as “video display area”) and a video non-display area (hereinafter referred to as “non-video display area”). May be formed). Patent Document 1 discloses that when the non-video display area occurs, the fluorescent tube corresponding to the non-video display area is turned off.
JP 2004-184993 A

However, as in Patent Document 1, when the fluorescent tube corresponding to the non-video display area is turned off, the edge of the video display area is not illuminated by the fluorescent tube. There is a problem in that the amount of light emitted by the backlight device differs between the vicinity of the central portion and the edge portion, and uneven brightness or color occurs between the central portion and the edge portion of the display image.
Accordingly, the present invention has been made in view of the above circumstances, and the object of the present invention is to reduce the power consumption of the backlight device while reducing the power consumption by the backlight unit and the vicinity of the center of the edge of the video display area. It is an object of the present invention to provide a display device capable of preventing brightness unevenness and color unevenness in the meantime and a television receiver including the same.

To achieve the above object, the present invention comprises video display means for displaying video based on an input video signal, and a backlight device having a plurality of light emitting means for illuminating the video display means from behind. The video display means detects a video display area where video is displayed or a non-video display area where video is not displayed, and is applied to a video display apparatus which controls the presence or absence of light emission of each of the light emitting means based on the detection result. The light emitting means disposed in a position corresponding to the video display area and the light emitting means adjacent to the outside of the light emitting means are caused to emit light, and the light emission excluding the light emitting means is excluded. The video display device is characterized in that the means is turned off. Here, the light emitting means is, for example, a fluorescent tube or a light emitting diode.
According to the present invention, the brightness between the vicinity of the center of the display image and the edge is prevented by preventing the difference in the amount of light emitted by the backlight device between the vicinity of the center of the image display area and the edge. Unevenness and color unevenness can be prevented, and power consumption by the backlight device can be reduced.
In the present invention, the video display unit detects the video display area and the non-video display area of the video in the video display means, and controls the presence or absence of light emission of the plurality of light emitting means based on the detection result. The present invention can be applied to a configuration in which the size and position of a video to be displayed can be changed. At this time, the change mode of the size and position of the video may be set in advance or may be arbitrarily changed.
The present invention may be regarded as a television receiver including the video display device configured as described above.

  According to the present invention, the brightness between the vicinity of the center of the display image and the edge is prevented by preventing the difference in the amount of light emitted by the backlight device between the vicinity of the center of the image display area and the edge. Unevenness and color unevenness can be prevented, and power consumption by the backlight device can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that the present invention can be understood. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.
FIG. 1 is a block diagram showing a schematic configuration of the television receiver X according to the embodiment of the present invention. FIG. 2 is a block diagram showing a schematic configuration of the liquid crystal display device Y according to the embodiment of the present invention. FIG. 3 is a schematic view of a main part of the liquid crystal display device Y as viewed from behind, FIG. 4 is a flowchart for explaining an example of a procedure of backlight control processing executed in the liquid crystal display device Y, and FIG. It is a figure for demonstrating the specific example of the light emission state of the backlight apparatus 26 in the said liquid crystal display device Y when the light control process is performed.
First, the configuration of the television receiver X according to the embodiment of the present invention will be described using the block diagram shown in FIG.
As shown in FIG. 1, the television receiver X includes a plurality of tuners 1a and 1b, a plurality of video processing circuits 4a and 4b, a screen composition switching circuit 5, a control circuit 8, a remote controller 9a, and a remote control interface. An (I / F) circuit 9, an audio switching circuit 10, an audio processing circuit 11, an amplifier 12, a speaker 13, and a liquid crystal display device Y (an example of a video display device) are schematically configured. . In addition to these, it also includes components of a general television receiver.

The tuners 1a and 1b receive broadcast information such as television broadcast and audio broadcast including video and audio from the broadcast receiving antenna 20. Here, the broadcast information includes broadcast information of a plurality of channels broadcast from a plurality of broadcasting stations.
The tuners 1a and 1b extract (select) the broadcast information of the broadcast channel designated by the control circuit 8, and transmit the video signal included in the broadcast information to the video processing circuits 4a and 4b. An audio signal included in the broadcast information is transmitted to the audio switching circuit 10.

The video processing circuit 4a performs various signal processing on the video signal transmitted from the tuner 1a, and the video processing circuit 4b performs various signals on the video signal transmitted from the tuner 1b. The processing is performed. For example, the video processing circuits 4a and 4b may perform A / D conversion of video signals, separation of horizontal and vertical synchronization signals from the A / D converted video signals, generation of clock signals phase-synchronized with the synchronization signals, A Separation of luminance and color signals from the video signal after / D conversion, predetermined image quality improvement processing, and the like are performed.
Video signals subjected to various signal processing in the video processing circuits 4a and 4b are transmitted from the video processing circuits 4a and 4b to the screen composition switching circuit 5.

In accordance with an instruction from the control circuit 8, the screen composition switching circuit 5 is configured to display a single video signal corresponding to a single display state in which one video is displayed on one screen and a dual video that displays two videos by dividing one screen. One of the dual video signals corresponding to the display state is generated, and the video signal is transmitted to the liquid crystal display device Y. The liquid crystal display device Y will be described in detail later.
Further, the screen composition switching circuit 5 replaces the insertion information transmitted from the control circuit 8 with the function of superimposing the inserted information on the video signal to be output or the output video from the video processing circuits 4a and 4b. It also has a function of converting information transmitted from the control circuit 8 into a video signal and outputting it.

The audio switching circuit 10 receives an arbitrary one of the audio signals transmitted from the tuners 1 a and 1 b (a set of audio signals in the case of stereo) according to an instruction from the control circuit 8. The data is transmitted to the audio processing circuit 11.
The audio processing circuit 11 performs various signal processing such as equalization processing and surround processing on the audio signal transmitted from the audio switching circuit 10 in accordance with an instruction from the control circuit 8.
The amplifier 12 performs a process of amplifying or attenuating the audio signal after various signal processing by the audio processing circuit 11 in accordance with an instruction from the control circuit 8. The audio signal amplified or attenuated by the amplifier 12 is input to the speaker 13 that outputs audio based on the audio signal.

The control circuit 8 includes an MPU 8a which is an arithmetic means, a ROM 8b (EPROM) which is a storage means in which a control program executed by the MPU 8a is stored in advance, an EEPROM 8c which stores setting information written by processing executed by the MPU 8a, and the like. Provided, and controls the entire television receiver X.
The remote control interface circuit 9 acquires operation input information for the remote control 9a from the remote control (remote operation unit) 9a for operating the television receiver X by wireless transmission such as infrared transmission, and the operation input information is obtained. The data is transmitted to the control circuit 8. The remote controller 9a includes a channel selection key for selecting the channels of the tuners 1a and 1b, a volume control key for adjusting the volume, and an image in a backlight control process (see the flowchart of FIG. 4) described later. Video display operation keys and the like (not shown) for changing the display size and position of the image are provided.

Next, the liquid crystal display device Y will be described in detail with reference to FIGS.
As shown in FIG. 2, the liquid crystal display device Y includes a video change processing unit 21 that changes the display size and position of a video based on the video signal input from the screen composition switching circuit 5, and the liquid crystal display device Y. A display control unit 22 for controlling, a liquid crystal display panel 24 (an example of video display means) for displaying video based on the input video signal, a liquid crystal drive unit 23 for controlling driving of the liquid crystal display panel 24, and A backlight device 26 that illuminates the liquid crystal display panel 24 from behind and a backlight drive unit 25 that controls driving of the backlight device 26 are schematically configured.
The video change processing unit 21 executes processing for changing the display size and position of a video based on the video signal input from the screen composition switching circuit 5 based on an instruction from the control circuit 8. The instruction from the control circuit 8 is performed according to the operation of the video display operation key (not shown) provided on the remote controller 9a. Here, the video change processing unit 21 when executing such a change process corresponds to a video change means.
The display control unit 22 includes control devices such as a CPU, a ROM, and a RAM, and controls the liquid crystal display device Y by executing processing according to a predetermined control program stored in the ROM.

As shown in FIG. 3, the backlight device 26 includes a pair of fluorescent tubes 261 to 268 (an example of a light emitting unit) arranged in parallel in the vertical direction. In this embodiment, a configuration in which a plurality of pairs of fluorescent tubes are provided will be described. Of course, a configuration in which a plurality of sets of fluorescent tubes (one example of light emitting means) are provided may be used. Absent.
The backlight driving unit 25 individually controls whether or not each of the fluorescent tubes 261 to 268 emits light based on an instruction from the display control unit 22.

Hereinafter, an example of the procedure of the backlight control process executed in the liquid crystal display device Y will be described according to the flowchart of FIG. 4 and with reference to FIG. S1, S2,... Shown below represent identification symbols of processing procedures (steps). The backlight control process is started when a predetermined power ON operation is performed through the remote controller 9a.
First, in step S1, when a video signal is input from the screen composition switching circuit 5 to the video change processing unit 21 of the liquid crystal display device Y, an instruction from the control circuit 8 is given by the video change processing unit 21. Accordingly, processing for changing the size and position of the video (hereinafter referred to as “display video”) based on the video signal is executed. The video signal output from the video change processing unit 21 is input to the display control unit 22.
Here, as shown in FIG. 5A, it is assumed that the control circuit 8 has instructed the liquid crystal display panel 24 to display the display image in the size and position of the image display region R1. To do. Therefore, the area shown by hatching in FIG. 5A is a non-video area where no video is displayed. Note that, as described above, the size and position of the display image are changed according to an instruction input from the control circuit 8 in response to an operation of the image display operation key (not shown) provided on the remote controller 9a. It is changed by the processing unit 21.

Next, in step S2, the display control unit 22 detects a video display area in the display video. Here, the video display area R1 is detected as a video display area in the display video. In addition, detection of a non-video display area (a hatched area shown in FIG. 5A) where no video is displayed is also considered as another embodiment. Here, the display control unit 22 when executing such detection processing corresponds to a display area detecting means.
Thereafter, in the subsequent step S3, the display control unit 22 selects a fluorescent tube arranged at a position corresponding to the video display region R1 among the fluorescent tubes 261 to 268. Here, as shown in FIG. 5A, since the fluorescent tubes 263 to 266 are arranged at positions corresponding to the video display region R1, the fluorescent tubes 263 to 266 are selected.

In step S4, the backlight controller 25 is controlled by the display controller 22, so that the fluorescent tubes 263 to 266 selected in step S3 and the outside of the fluorescent tubes 263 to 266 are adjacent to each other. Only the fluorescent tubes 262 and 267 emit light. That is, among the fluorescent tubes 261 to 268, the fluorescent tubes 261 and the fluorescent tubes 268 other than the fluorescent tubes 262 to 267 are turned off. Therefore, in the liquid crystal display device Y, since the fluorescent tubes 261 and 268 are turned off, it is possible to reduce useless power consumption for turning on the fluorescent tubes 261 and 268.
Here, the fluorescent tubes 263 to 266 arranged at positions corresponding to the image display region R1 and the fluorescent tubes 262 and 267 adjacent to the outside of the fluorescent tubes 263 to 266 are caused to emit light, and the fluorescent tube 261 is emitted. , 268 is turned off, the display control unit 22 corresponds to the light emission control means. Although the fluorescent tube 261 and the fluorescent tube 268 are turned off here, reducing the illuminance of the fluorescent tube 261 and the fluorescent tube 268 may be considered as another embodiment.
By the way, in the conventional apparatus (for example, refer to Patent Document 1), in such a case, only the fluorescent tubes 263 to 266 arranged at positions corresponding to the video display area R1 emit light. Lightness unevenness and color unevenness occurred between the vicinity of the center of R1 and the edge.
However, in the liquid crystal display device Y according to the embodiment of the present invention, not only the fluorescent tubes 263 to 266 disposed at positions corresponding to the video display region R1, but also adjacent to the outside of the fluorescent tubes 263 to 266. Since the fluorescent tubes 262 and 267 emit light, brightness unevenness and color unevenness do not occur between the vicinity of the central portion and the edge of the video display region R1.

Thereafter, in step S5, the display control unit 22 determines whether or not the size and position of the display video, that is, the video display area R1 has been changed. Specifically, the determination is made based on the video signal output from the video change processing unit 21. The process of step S5 is repeatedly executed until it is determined that the size or position of the display image has been changed (No in S5).
On the other hand, an instruction to change the size or position of the display image is input from the control circuit 8 to the image change processing unit 21 in response to an operation of the image display operation key (not shown) provided on the remote controller 9a. If so, it is determined that the size or position of the display video has been changed (Yes in S5), and the process moves to step S2. In step S2, the video display area in the display video after the size or position has been changed is detected, and the processing after step S3 is executed again.
For example, as shown in FIG. 5B, when the size and position of the display image are changed and the display image is displayed at the size and position of the image display area R2, the same processing is performed. The fluorescent tubes 261 to 266 emit light, and the fluorescent tubes 267 and 268 are turned off. 5A is a non-video area where no video is displayed.
In the present embodiment, the configuration in which the plurality of fluorescent tubes 261 to 268 are arranged in the vertical direction has been described. However, the present invention is similarly applied to a configuration in which the fluorescent tubes 261 to 268 are arranged in the horizontal direction. Is possible.

In the embodiment, the example in which the video display area of the display screen is detected and the presence or absence of light emission of the fluorescent tubes 261 to 268 is controlled based on the detected video display area has been described.
Here, an example of processing executed when it is determined in step S5 that the size or position of the display image has been changed will be described.
FIG. 6 is a flowchart for explaining another example of the procedure of the backlight control process. In addition, the same code | symbol is attached | subjected about the process similar to the said backlight control process in the said embodiment, and the description is abbreviate | omitted.
As shown in FIG. 6, when it is determined in step S5 that the size or position of the display image has been changed (Yes in S5), the process proceeds to step S6.
In step S <b> 6, the movement amount of the upper end of the display image is detected by the display control unit 22. Specifically, the detection of the amount of movement of the upper end of the display image is input from the control circuit 8 to the image change processing unit 21 in accordance with the operation amount of the image display operation key (not shown) of the remote controller 9a. This is performed based on the instruction signal. Here, the movement amount of the upper end of the display image is + in the upward direction and-in the downward direction. Note that the upper end of the display image is moved by changing the size or position of the display image.

In subsequent steps S7 and S8, the display control unit 22 determines whether the movement amount of the upper end of the display image detected in step S6 is + T1 or more (S7) or -T1 or more (S8). The Here, the T1 is, for example, an arrangement interval of the fluorescent tubes 261 to 268 and is set in advance.
Here, when it is determined that the amount of movement of the upper end of the display image is greater than or equal to + T1 (Yes side of S7), the process proceeds to step S71, and among the fluorescent tubes 261 to 268, light emission is in progress. A fluorescent tube adjacent to the outside (upper side) of the uppermost fluorescent tube of the fluorescent tube emits light.
On the other hand, when it is determined that the amount of movement of the upper end of the display image is equal to or greater than -T1 (Yes side of S8), the process proceeds to step S81, and among the fluorescent tubes 261 to 268, the light is being emitted. The uppermost fluorescent tube of the fluorescent tube is turned off.
When the amount of movement of the upper end of the display image is less than + T1 and less than −T1 (No side in S7 and S8), the light emission state of each of the fluorescent tubes 261 to 268 is maintained as it is, and the process is performed. The process proceeds to step S9.

In step S9 and subsequent steps, the same processing is performed on the lower end of the display image.
Specifically, first, in step S <b> 9, the display control unit 22 detects the amount of movement of the lower end of the display image. Specifically, the detection of the movement amount of the lower end of the display image is input from the control circuit 8 to the image change processing unit 21 according to the operation amount of the image display operation key (not shown) of the remote controller 9a. This is performed based on the instruction signal. Here, the amount of movement of the lower end of the display image is + in the upward direction and-in the downward direction.

In subsequent steps S10 and S11, the display control unit 22 determines whether the movement amount of the lower end of the display image detected in step S9 is + T1 or more (S10) or −T1 or more (S11). The
Here, when it is determined that the amount of movement of the lower end of the display image is equal to or greater than + T1 (Yes side of S10), the process proceeds to step S101, and among the fluorescent tubes 261 to 268, the light emission is being performed. The lowermost fluorescent tube of the fluorescent tube is turned off.
On the other hand, when it is determined that the movement amount of the lower end of the display image is equal to or greater than -T1 (Yes side of S11), the process proceeds to step S111, and among the fluorescent tubes 261 to 268, the light emission is in progress. A fluorescent tube adjacent to the outer side (lower side) of the lowermost fluorescent tube of the fluorescent tube emits light.
When the amount of movement of the lower end of the display image is less than + T1 and less than −T1 (No side in S10 and S11), the processing is performed while maintaining the light emission state of each of the fluorescent tubes 261 to 268. The process proceeds to step S5.
In this way, by controlling the presence or absence of light emission of each of the fluorescent tubes 261 to 268 based on the amount of movement of the upper and lower ends of the display image, the upper and lower edges and the vicinity of the center of the display image Brightness unevenness and color unevenness can be prevented.

FIG. 7 is a view for explaining a backlight device 36 which is another example of the backlight device 26.
In the above-described embodiment, the configuration in which the backlight device 26 includes the plurality of fluorescent tubes 261 to 268 has been described. However, the configuration in which the backlight device 26 includes a plurality of light emitting diodes (LEDs) instead of the plurality of fluorescent tubes 261 to 268 is also described. It is possible to apply. Further, the present invention can be similarly applied to a backlight device configured by combining a fluorescent tube and an LED.
In the second embodiment, instead of the backlight device 26, a configuration in which a backlight device 36 having LED groups 361 to 390 including a plurality of LEDs as a set is provided as shown in FIG. It is assumed that the presence or absence of light emission of each of the LED groups 361 to 390 can be individually controlled by the backlight driving unit 25.
In such a configuration, when an image is displayed in the image display region R3 shown in FIG. 7, the LED groups 366 to 368, 371 to 373, and 376 to 378 arranged at positions corresponding to the image display region R3 The LED groups 361 to 364, 369, 374, 379, and 381 to 384 adjacent to the outside of the LED groups 366 to 368, 371 to 373, and 376 to 378 are turned on. Then, the LED groups 365, 370, 375, 380, 385, 386 to 390 except for these LED groups are controlled to be turned off.
As described above, in the configuration including the plurality of LED groups 361 to 390, unnecessary LED groups can be turned off at the top, bottom, left, and right of the video display region R3.

1 is a block diagram showing a schematic configuration of a television receiver according to an embodiment of the present invention. 1 is a block diagram showing a schematic configuration of a liquid crystal display device according to an embodiment of the present invention. The principal part schematic diagram which looked at the liquid crystal display device which concerns on embodiment of this invention from back. 6 is a flowchart for explaining an example of a procedure of backlight control processing executed in the liquid crystal display device according to the embodiment of the present invention. The figure for demonstrating the specific example of the light emission state of the backlight apparatus when the backlight control process is performed. The flowchart for demonstrating the other example of the procedure of a backlight control process. The figure for demonstrating the other example of a backlight apparatus.

Explanation of symbols

1a, 1b ... tuners 4a, 4b ... video processing circuit 5 ... screen composition switching circuit 8 ... control circuit 9 ... remote control interface circuit 9a ... remote control 10 ... audio switching circuit 11 ... audio processing circuit 12 ... amplifier 13 ... speaker 20 ... broadcast reception Antenna 21 ... Video change processing unit 22 ... Display control unit 23 ... Liquid crystal drive unit 24 ... Liquid crystal display panel 25 ... Backlight drive unit 26 ... Backlight device X ... Television receiver Y ... Liquid crystal display device (an example of a video display device) )
S1, S2,... Processing procedure (step) number

Claims (4)

Video display means for displaying video based on the input video signal;
A backlight device having a plurality of light emitting means for illuminating the video display means from behind;
Display area detecting means for detecting a video display area in which video is displayed in the video display means and / or a non-video display area in which video is not displayed;
A light emission control means for controlling the presence or absence of light emission of each of the light emission means based on the detection result by the display area detection means;
A video display device comprising:
The light emission control means causes the light emission means arranged at a position corresponding to the video display area among the plurality of light emission means and the light emission means adjacent to the outside of the light emission means to emit light, and the light emission means excluding the light emission means A video display device characterized by being turned off.   The video display device according to claim 1, wherein the light emitting means is a fluorescent tube and / or a light emitting diode.   The video display device according to claim 1, further comprising video changing means for changing a size and / or position of a video displayed on the video display unit.   A television receiver comprising the video display device according to claim 1.

Images