JP2008224780A - Television apparatus and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a television apparatus and a display device capable of maintaining the brightness of an image displayed on a display part without having an effect on the life of a backlight. <P>SOLUTION: The television apparatus includes a liquid crystal panel 9a for displaying images, a backlight 9b for irradiating the liquid crystal panel 9a with light and a control section 11 for controlling setting in the brightness of an image. The control section 11 is configured so as to control setting in the brightness of an image according to the total emitting time of the backlight 9b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a television device and a display device, and more particularly to a television device and a display device including a display unit that displays an image and a backlight that illuminates the display unit.

  2. Description of the Related Art Conventionally, a display device including a display unit that displays an image and a backlight that illuminates the display unit is known (see, for example, Patent Documents 1 to 3).

  Patent Document 1 discloses a liquid crystal panel (display unit) that displays an image, a backlight that irradiates the liquid crystal panel from the back, and a counter that measures the cumulative usage time (total light emission time) of the backlight (total light emission of the backlight). A liquid crystal television (display device) including a time measurement unit) and a microcomputer (control unit) that outputs a pulse signal for adjusting the luminance (brightness) of the backlight is disclosed. In the liquid crystal television according to Patent Document 1, the microcomputer is configured to extend the lifetime of the backlight by changing the pulse signal according to the accumulated usage time of the backlight, thereby reducing the brightness of the backlight. Has been.

  Patent Document 2 discloses an electro-optical panel (display unit) that displays an image, a backlight device that illuminates the panel, a photometric sensor that measures the illuminance of external light around the panel, and the temperature around the panel. An electro-optical device (display device) including a side temperature sensor to be measured and a light source driving condition adjusting unit that adjusts the luminance of the backlight device is disclosed. In the electro-optical device according to Patent Document 2, the light source driving condition adjustment unit adjusts the brightness of the backlight device according to the illuminance and temperature of the ambient light around the panel, thereby adjusting the brightness of the image displayed on the panel. It is the composition to do.

  Patent Document 3 discloses a liquid crystal display unit that displays an image, a backlight that illuminates the liquid crystal display unit, a use condition defining unit that presets use conditions such as a season and time to be used, and a backlight. A display device including a control unit (control unit) for adjusting luminance is disclosed. In the display device according to Patent Document 3, the control means adjusts the brightness of the image displayed on the liquid crystal display unit by adjusting the luminance of the backlight in accordance with preset use conditions. .

JP 2006-245925 A JP 2006-39242 A JP 2000-58274 A

  However, in the liquid crystal television described in Patent Document 1, since the backlight brightness is adjusted to be dark according to the accumulated usage time of the backlight, it is possible to extend the lifetime of the backlight. Thus, there is a problem that the brightness of the image displayed on the liquid crystal panel cannot be maintained when the accumulated time of the backlight is long.

  In the electro-optical device described in Patent Document 2, the brightness of the image displayed on the display unit is adjusted by adjusting the brightness of the backlight. When the brightness of the backlight decreases, it is necessary to adjust the backlight brightness to be brighter in order to maintain the brightness of the video. For this reason, in the electro-optical device described in the above-mentioned Patent Document 2, in order to maintain the brightness of the image displayed on the display unit, the brightness of the backlight whose lifetime is approaching is adjusted to be increased. There is a problem that the life is shortened.

  Further, in the display device described in Patent Document 3, it is possible to adjust the brightness of the image displayed on the liquid crystal display unit by adjusting the brightness of the backlight according to the preset use conditions. On the other hand, the brightness of the video displayed on the display unit cannot be adjusted in accordance with the decrease in the brightness of the backlight as the lifetime of the backlight approaches, so the brightness of the video can be maintained. There is a problem that it is not possible.

  The present invention has been made to solve the above problems, and one object of the present invention is to maintain the brightness of the image displayed on the display unit without affecting the lifetime of the backlight. It is an object of the present invention to provide a television device and a display device that can be used.

Means for Solving the Problems and Effects of the Invention

  A television apparatus according to a first aspect of the present invention is a television apparatus including a display unit that displays an image and a backlight that illuminates the display unit, and a control unit that controls the setting of the brightness of the image; And a backlight total light emission time measuring unit for measuring the total light emission time of the backlight. The video displayed on the display unit is expressed by red, green, and blue, which are the three primary colors of light, and the control unit makes the brightness setting of the video brighter according to the total light emission time of the backlight. The control of the brightness setting of the video by the control unit is performed by adjusting the set values of the respective gradations of the three primary colors red, green and blue, and the total light emission time of the backlight The brightness of the video is adjusted step by step in accordance with the increase in the image quality.

  In the television apparatus according to the first aspect, as described above, the display unit that displays the image, the backlight that illuminates the display unit, and the control unit that controls the setting of the brightness of the image are provided. Is configured to control the brightness setting of the video to be brighter according to the total light emission time of the backlight, thereby increasing the brightness of the backlight when the backlight brightness decreases. Thus, the brightness of the video displayed on the display unit can be maintained without adjustment, and it is not necessary to adjust the brightness of the backlight to be bright, so that the lifetime of the backlight is not affected.

  Further, in the television device according to the first aspect, since the backlight total light emission time measuring unit that measures the total light emission time of the backlight can be further provided, the total time that the backlight emits light can be measured. The brightness of the image can be adjusted according to the total light emission time of the backlight. In addition, as the control unit is configured to adjust the brightness setting of the video step by step according to the increase in the total light emission time of the backlight, the total light emission time of the backlight increases. When the brightness of the backlight gradually decreases, the control unit can complement the decrease in the brightness of the video step by step. In addition, the control unit is configured to adjust the set values of the respective gradations of red, green, and blue, which are the three primary colors of light, according to the total light emission time of the backlight. Since the brightness of each of the three primary colors red, green and blue can be adjusted, the brightness of the image can be adjusted according to the total light emission time of the backlight.

  A display device according to a second aspect of the present invention includes a display unit that displays an image, a backlight that illuminates the display unit, and a control unit that controls setting of brightness of the image. The control unit includes a backlight. The brightness setting of the video is controlled to be brighter according to the total light emission time.

  In the display device according to the second aspect, as described above, the display unit that displays the video, the backlight that illuminates the display unit, and the control unit that controls the setting of the brightness of the video are provided. By configuring to control the brightness of the video to be brighter according to the total lighting time of the backlight, so that the backlight brightness is increased when the backlight brightness decreases The brightness of the image displayed on the display unit can be maintained without being adjusted, and it is not necessary to adjust the brightness of the backlight to be increased, so that the lifetime of the backlight is not affected.

  The display device according to the second aspect preferably further includes a backlight total light emission time measuring unit that measures the total light emission time of the backlight. With this configuration, since the total time during which the backlight emits light can be measured, the brightness of the image can be adjusted according to the total light emission time of the backlight.

  In the display device according to the second aspect, preferably, the control unit is configured to adjust the brightness setting of the video stepwise in accordance with an increase in the total light emission time of the backlight. With this configuration, when the backlight brightness gradually decreases as the total light emission time of the backlight increases, the control unit complements the decrease in the image brightness step by step. can do.

  In the display device according to the second aspect, preferably, an image displayed on the display unit is represented by red, green, and blue that are the three primary colors of light, and the control unit is configured according to the total light emission time of the backlight. It is configured to adjust the set values of the respective gradations of red, green and blue which are the three primary colors of light. With this configuration, the control unit can adjust the brightness of each of the three primary colors of light, red, green, and blue. Therefore, the brightness of the image can be adjusted according to the total light emission time of the backlight. Can be adjusted.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram for explaining a configuration of a liquid crystal television apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing the life characteristics of the backlight of the liquid crystal television apparatus according to the embodiment of the present invention shown in FIG. 1 and the change in the brightness setting of the image. First, with reference to FIG. 1 and FIG. 2, the structure of the liquid crystal television apparatus 100 by one Embodiment of this invention is demonstrated. In the present embodiment, a case where the present invention is applied to a liquid crystal television device which is an example of a television device and a display device will be described.

  As shown in FIG. 1, a liquid crystal television set 100 according to an embodiment of the present invention includes a television receiver 1 that receives a digital television signal and an analog television signal via a television antenna 20, and a high definition multimedia (HDMI). The digital signal receiving unit 2 that receives a digital signal from the digital external device 30 and the component connection, the composite connection, and the PC input interface, in addition to the interface) and the DVI-D (Digital Visual Interface Digital) standard And an analog signal receiving unit 3 that receives an analog signal from the analog external device 40. Here, the HDMI standard is one of connection standards in which a television apparatus and a video player or DVD apparatus are connected, and not only video but also audio and control signals can be transferred with a single cable. The -D standard is one of connection standards for transmitting and receiving digital signals used in a DVI interface that connects a computer and a monitor (display unit).

  The liquid crystal television set 100 is selected by the A / D selector 4 that selects one of the digital television signal and the analog television signal received by the television receiver 1, and the A / D selector 4. And an AV decoder 5 for decoding the digital television signal and a three-dimensional Y / C separation circuit unit 6 for Y / C separation of the analog television signal.

  In addition, the liquid crystal television device 100 includes any one of video data based on signals transmitted from the digital signal receiving unit 2, the analog signal receiving unit 3, the AV decoder 5, and the three-dimensional Y / C separation circuit unit 6. An AV selector 7 for selecting a video, a video processing unit 8 for processing the video data selected by the AV selector 7, a liquid crystal monitor 9 for displaying video based on the video data subjected to the video processing, and various data A memory 10 to be stored and a control unit 11 for controlling the setting of the brightness of the video displayed on the liquid crystal monitor 9 are further provided. Each component is configured to be able to communicate a control signal and control data with each other by being connected to each other via a bus (transmission path) 12.

  Also, the television receiver 1 extracts a digital modulation signal having a frequency arbitrarily selected from the high frequency digital modulation signal for the digital television signal, and demodulates the selected digital modulation signal to demodulate the A / D selector. 4 is configured to output to 4. Further, the television receiver 1 is configured to demodulate a broadcast signal wave having a selected frequency and output the analog television signal to the A / D selector 4.

  The analog signal receiving unit 3 is configured to perform A / D conversion processing (analog / digital conversion processing), and to perform Y / C separation on signals received through composite connection.

  In addition, the video processing unit 8 adjusts the size of the video displayed on the liquid crystal monitor 9 based on the video data selected by the AV selector 7, and the video brightness, contrast, and It is configured to adjust image quality such as hue. The video processing unit 8 is configured to convert the digital video data in YCbCr format selected by the AV selector 7 into digital video data in RGB format so that it can be displayed on the liquid crystal monitor 9. Here, the YCbCr format is one of color separation formats in which colors are expressed by a luminance signal (Y) and difference signals (Cb and Cr). The RGB format is composed of the three primary colors of light, red (R), green (G), and blue (B), and various colors can be expressed by combining the RGB colors. For example, when a memory capacity of 8 bits is assigned to each RGB color, it is possible to express 256 gradations of brightness, and as a result, express more than 16.77 million colors. It is possible.

  Here, in the present embodiment, the liquid crystal monitor 9 includes a liquid crystal panel 9a that displays an image and a backlight 9b that irradiates the liquid crystal panel 9a from the back side. The liquid crystal panel 9a includes a liquid crystal material (not shown) sandwiched between two transparent glass plates (not shown), and light emitted from the backlight 9b based on the amount of voltage applied to the liquid crystal material. Is transmitted through a color filter (not shown) composed of red, green and blue disposed on the front side of the glass plate (the side opposite to the side where the backlight 9b is disposed). The amount of light to be adjusted is configured. Thereby, in this embodiment, the image displayed on the liquid crystal monitor 9 is expressed by a combination of brightness of 256 gradations (brighter as the gradation value is larger) of 0 to 255 of red, green, and blue, respectively. It is configured to be possible. The liquid crystal panel 9a is an example of the “display unit” in the present invention.

  As shown in FIG. 2, the backlight 9b has a life characteristic in which the brightness gradually decreases when the total light emission time, which is the sum of the light emission times, exceeds a certain time. Further, the total light emission time of the backlight is configured to be measured by the backlight total light emission time measuring unit 13 (see FIG. 1). The backlight total light emission time measuring unit 13 is connected to the control unit 11 via the bus 12. It is connected so that it can communicate with.

  In the present embodiment, the memory 10 stores a table for adjusting the respective gradations of red, green, and blue in the RGB format. FIG. 3 is a diagram showing an example of a table stored in the memory of the liquid crystal television apparatus according to the embodiment of the present invention shown in FIG. Here, the configuration of an RGB value setting table 10a, which is an example of a table, will be described with reference to FIG. The RGB value setting table 10a is a table assuming that the backlight 9b has a backlight life characteristic in which the brightness gradually decreases when the total light emission time exceeds 8000 hours, and the red, It is configured to be used in common for all of green and blue.

  First, in the present embodiment, when digital video data is converted from the YCbCr format to the RGB format by the video processing unit 8, red, green, and red in the RGB format based on the color information included in the video data in the YCbCr format. In blue, values from 0 to 220 gradations are set as initial values (see the leftmost column in FIG. 3). The RGB setting value table 10a includes information on gradation values adjusted with respect to initial values for each predetermined total light emission time of the backlight 9b. For example, when the total light emission time of the backlight 9b exceeds 8250 hours, as shown in the third column from the left in FIG. 3, the gradation value becomes 2% larger than the initial value. Further, when the total light emission time of the backlight 9b exceeds 9000 hours as the final adjustment time, as shown in the rightmost column of FIG. 3, the gradation value is 20% larger than the initial value. It is configured. As described above, the gradation value is adjusted at a ratio with respect to the initial value according to the total light emission time of the backlight 9b, so that a gradation having a larger value (brighter) has a gradation adjusted to the initial value. The difference from the value becomes larger. As a result, when the brightness of the backlight 9b decreases and the color (brightness) that should be originally expressed cannot be expressed, a more effective adjustment can be performed for brighter colors that are more easily affected. Is possible. In the present embodiment, the maximum (brightest) gradation value of the initial values of red, green, and blue is set to 220. Further, when the total light emission time exceeds 9000 hours, the gradation value becomes 20% larger than the initial value. Therefore, when the initial value is 220 gradations, the adjusted gradation value exceeds 255. In this embodiment, the maximum gradation value is adjusted to 255.

  Further, as described above, the backlight 9b has a characteristic that the brightness gradually decreases when a certain total light emission time is exceeded, but as shown in FIG. 2, the brightness setting is increased accordingly. By adjusting in this way, it is possible to compensate for a decrease in the brightness of the video.

  Here, in the present embodiment, the control unit 11 adjusts the brightness setting of the video displayed on the liquid crystal monitor 9 based on the RGB value setting table 10a according to the total light emission time of the backlight 9b. It is configured. Specifically, based on the RGB value setting table 10a, the control unit 11 controls the brightness of the video to be brighter according to the total light emission time of the backlight 9b, and the video by the control unit 11 The brightness setting is controlled by adjusting the setting values of the respective gradations of the RGB colors, and the brightness of the video is set step by step as the total light emission time of the backlight 9b increases. Is configured to adjust. As a result, when the brightness of the backlight 9b gradually decreases as the total light emission time of the backlight 9b increases, the control unit 11 does not adjust the brightness of the backlight 9b to increase the video. It is possible to compensate for the decrease in brightness of the image step by step, and as a result, maintain the brightness of the image. In addition, since it is not necessary to adjust the brightness of the backlight 9b to increase, the lifetime of the backlight 9b is not affected.

  FIG. 4 is a flowchart for explaining the video signal processing operation of the liquid crystal television apparatus according to the embodiment of the present invention shown in FIG. Next, a video signal processing operation of the liquid crystal television apparatus 100 according to an embodiment of the present invention will be described with reference to FIG.

  First, in step S1 of FIG. 4, the television receiver 1, the digital signal receiver 2, and the analog signal receiver 3 receive video signals of corresponding formats. In step S 2, the video signal is demodulated, three-dimensional Y / C separated, and A / D converted as necessary, and transmitted to the AV selector 7. Next, in step S3, the size of the video data selected by the AV selector 7 is adjusted by the video processing unit 8. In step S4, image quality adjustments such as video brightness, contrast, and hue are performed based on default or user settings, and when the total light emission time of the backlight 9b exceeds a predetermined time, Based on the RGB value setting table 10a, the brightness setting of the video is adjusted. In step S5, an image is displayed on the liquid crystal monitor 9 based on the gradation value whose setting has been adjusted, and the operation ends.

  FIG. 5 is a flowchart for explaining the operation of adjusting the set value of the RGB format gradation of the liquid crystal television apparatus according to the embodiment of the present invention shown in FIG. Next, with reference to FIG. 5, an operation of adjusting the set value of the RGB format gradation of the liquid crystal television apparatus 100 according to the embodiment of the present invention will be described.

  First, in step S11 of FIG. 5, it is determined whether or not the backlight 9b is emitting light. If it is determined that the backlight 9b is not emitting light, this determination is repeated. On the other hand, if it is determined that the backlight 9b is emitting light, the total light emission time of the backlight 9b is measured by the backlight total light emission time measuring unit 13 in step S12. Then, in step S13, it is determined whether or not the total light emission time of the backlight 9b has exceeded a predetermined total light emission time. If it is determined that the predetermined total light emission time has not been exceeded, this determination is repeated. . On the other hand, if it is determined that the predetermined total light emission time has been exceeded, in step S14, the set values of the respective gradations of red, green and blue in the RGB format are adjusted based on the RGB value setting table 10a. . In step S15, it is determined whether or not the total light emission time of the backlight 9b has exceeded the final adjustment time. If it is determined that the total light emission time has not exceeded, the process proceeds to step S13, where it is determined that it has exceeded. If so, the operation is terminated.

  In the present embodiment, as described above, the liquid crystal panel 9a that displays an image, the backlight 9b that illuminates the liquid crystal panel 9a, and the control unit 11 that controls the setting of the brightness of the image are provided. The brightness of the backlight 9b is reduced when the brightness of the backlight 9b is reduced by controlling the brightness setting of the image to be brighter according to the total light emission time of the backlight 9b. The brightness of the image displayed on the liquid crystal panel 9a can be maintained without adjusting it to be bright, and it is not necessary to adjust the brightness of the backlight 9b to increase the life of the backlight 9b. Does not affect.

  Further, in the present embodiment, the controller 11 is configured to adjust the brightness setting of the video in stages in accordance with the increase in the total light emission time of the backlight 9b, whereby the total light emission of the backlight 9b. When the brightness of the backlight 9b gradually decreases as the time increases, the control unit 11 can complement the decrease in the brightness of the video step by step.

  In the present embodiment, the video to be displayed on the liquid crystal panel 9a is expressed in RGB format red, green, and blue, and the control unit 11 controls each color of the RGB format according to the total light emission time of the backlight 9b. Since the control unit 11 can adjust the brightness of each color by adjusting the set value of the gradation, it is possible to adjust the brightness of the video according to the total light emission time of the backlight 9b. it can.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, the liquid crystal television device is shown as an example of the television device and the display device. However, the present invention is not limited thereto, and any display device including a backlight may be used. The present invention can also be applied to other television devices and display devices.

  In the above embodiment, an example in which an image is expressed in the RGB format has been described. However, the present invention is not limited to this, and other formats can be used as long as the image brightness setting can be adjusted. It may be used.

  In the above embodiment, an example in which the setting value of the gradation of each color in the RGB format is adjusted at a ratio to the initial value is shown. However, the present invention is not limited to this, and the brightness of the backlight is reduced. If it can be complemented, for example, an adjustment may be made using an offset value, or an adjustment value may be set uniquely for each gradation.

It is a block diagram for demonstrating the structure of the liquid crystal television apparatus by one Embodiment of this invention. It is the figure which showed the lifetime characteristic of the backlight of the liquid crystal television apparatus by one Embodiment of this invention shown in FIG. 1, and the brightness setting of an image | video. It is the figure which showed an example of the table memorize | stored in the memory of the liquid crystal television apparatus by one Embodiment of this invention shown in FIG. 3 is a flowchart for explaining a video signal processing operation of the liquid crystal television device according to the embodiment of the present invention shown in FIG. 1. 3 is a flowchart for explaining an operation of adjusting a set value of RGB format gradation in the liquid crystal television device according to the embodiment of the present invention shown in FIG. 1;

Explanation of symbols

9a LCD panel (display unit)
9b Backlight 11 Control unit 13 Backlight total light emission time measurement unit 100 Liquid crystal television device (television device and display device)

Claims (5)

In a television device comprising a display unit for displaying video and a backlight for illuminating the display unit,
A control unit for controlling the brightness setting of the image;
A backlight total light emission time measuring unit for measuring the total light emission time of the backlight,
The video to be displayed on the display unit is represented by red, green and blue which are the three primary colors of light,
The controller controls the brightness setting of the video to be brighter according to the total light emission time of the backlight,
The control of the brightness setting of the video by the control unit is performed by adjusting setting values of the respective gradations of red, green, and blue that are the three primary colors of the light, and the total light emission time of the backlight. The television apparatus is configured to adjust the brightness setting of the video in a step-by-step manner in accordance with an increase in. A display unit for displaying images;
A backlight for illuminating the display unit;
A control unit for controlling the brightness setting of the video,
The display device is configured to control the brightness setting of the video to be brighter according to the total light emission time of the backlight.   The display device according to claim 2, further comprising a backlight total light emission time measuring unit that measures a total light emission time of the backlight.   The display device according to claim 2, wherein the control unit is configured to adjust the brightness setting of the video stepwise in accordance with an increase in the total light emission time of the backlight. The video to be displayed on the display unit is represented by red, green and blue which are the three primary colors of light,
The said control part is comprised so that the setting value of each gradation of red, green, and blue which is three primary colors of the said light may be adjusted according to the total light emission time of the said backlight. 5. The display device according to any one of 4.

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