JP2013134335A - Liquid crystal display device and liquid crystal television - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device and a liquid crystal television which are capable of achieving an image in vivid color even in a high-brightness area while enhancing the feeling of contrast.SOLUTION: When processing is performed by a contrast emphasis unit 151, a backlight area control unit 15 detects areas of a backlight 17 being high-brightness areas, by a high-brightness area detection unit 152. A ratio of brightness of LEDs 17R, 17G, and 17B in each of the areas detected as high-brightness areas by the high-brightness area detection unit 152 is changed by an LED brightness determination unit 153.

Description

  The present invention relates to a liquid crystal display device and a liquid crystal television that display a color image by using a backlight including a plurality of light sources that emit light of a plurality of colors corresponding to a plurality of color filters.

  The liquid crystal display device displays an image by allowing a liquid crystal panel to transmit or block light emitted from a backlight. In recent years, a driving method has been used in which a backlight is divided into a plurality of areas and the luminance is controlled for each area. Local dimming technology and HDR (High Dynamic Range) technology are known as technologies using such a method.

  The local dimming technique is a technique for displaying a low-brightness area at a lower brightness by lowering the brightness of the backlight area corresponding to the part of the displayed video when the brightness is low. . In addition, HDR technology not only displays a low-brightness area at a lower brightness, but also increases the brightness of the backlight area corresponding to that portion when a part of the video is high-brightness. This is a technique for increasing the contrast of the entire image by displaying the above area with higher brightness.

  A liquid crystal display device using an RGB-LED light source composed of LEDs (Light-Emitting Diodes) of three colors of red (R), green (G), and blue (B) as a backlight has also been proposed (Patent Literature). 1). In such a liquid crystal display device, not only the brightness is raised and lowered for each area, but also the color purity of the primary colors of red, green and blue can be increased by controlling the brightness of each of the three color LEDs in each area. And the color gamut of the displayed image can be increased.

JP 2007-322944 A

When the above-described HDR technology is used, there is a problem that, in a high brightness region, the display becomes brighter by displaying at a higher brightness, but the color becomes lighter. As a method for solving this problem, a method of darkening a color in a high-luminance region is conceivable. However, for example, in a case where an IC (Integrated Circuit) that performs processing related to HDR technology and an IC that performs various processing on a video signal in order to display an image, which region of the image should be increased, It is difficult to acquire information such as the timing to raise Therefore, in such a case, it is necessary to perform a process that affects other areas than the area that has become brighter by the HDR technology, such as darkening the color of the entire video.
In addition, it is possible to increase the contrast of the video by using the HDR technology, but depending on the video, if the contrast is increased unnecessarily, the video may be contrary to the directors intention.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a liquid crystal display device and a liquid crystal television capable of realizing a vivid image even in a high-brightness region while increasing contrast. And

  A liquid crystal display device according to the present invention includes a liquid crystal panel having a plurality of color filters, and a backlight having a plurality of color light sources that respectively emit light of colors corresponding to the color filters on a plane facing the liquid crystal panel. And a backlight control unit that controls the luminance of each light source of the backlight for each area obtained by dividing the light source into a plurality of areas, and displays a color video based on the input color video signal And a brightness control unit that raises and lowers the brightness of each area according to the brightness based on a color video signal displayed in each area where the light source of each area of the backlight emits light in the liquid crystal panel. A luminance determination unit that determines whether or not the luminance of each area that has been moved up and down by the luminance control unit is greater than or equal to a predetermined value; The ratio of the luminance of the light sources, characterized by comprising a high luminance region control unit for changing such that the color ratio of the corresponding color image displayed in the area.

  The liquid crystal display device according to the present invention is characterized in that the luminance control unit performs a process of lowering the luminance of the low luminance area and increasing the luminance of the high luminance area.

  The liquid crystal display device according to the present invention includes a necessity acceptance unit that accepts necessity of luminance control of each area by the luminance control unit, and the luminance control unit requires luminance control at the necessity acceptance unit. If accepted, a process for controlling the luminance of each area is performed.

  The liquid crystal display device according to the present invention includes a determination unit that determines the type of the color image, and the luminance control unit performs a process of controlling the luminance of each area according to the determination result of the determination unit. It is characterized by being.

  The liquid crystal display device according to the present invention includes a determination unit that determines a device from which the color video signal is transmitted, and the luminance control unit performs a process of controlling the luminance of each area according to the determination result of the determination unit. It is made to perform.

  The liquid crystal television according to the present invention includes a video receiving unit that receives a color video signal and any one of the liquid crystal display devices described above, and the liquid crystal display device is based on the color video signal received by the video receiving unit. A color image is displayed.

  In the present invention, the liquid crystal panel has a plurality of color filters, and the backlight has a plurality of color light sources that respectively emit light of colors corresponding to the color filters. In the backlight, the luminance of the light source included in each area is controlled for each of a plurality of areas divided in advance. Based on the color video signal displayed in each area of the liquid crystal panel where each area of the backlight emits light, the brightness of each area is increased or decreased according to the brightness. Also, if the brightness of each area that is moved up or down is greater than or equal to a predetermined value, the ratio of the brightness of each color in this area is changed to be the ratio of each color of the color video displayed in the corresponding area. The color of the luminance region can be darkened. By changing the luminance only for the area where the luminance is equal to or higher than the predetermined value, the other regions are not affected.

  In the present invention, by reducing the brightness of the low brightness area and increasing the brightness of the high brightness area, it is possible to suppress the occurrence of problems that occur in the high brightness area even when the contrast of the video is increased. . Therefore, the color of the high luminance region can be made clear while increasing the contrast.

  In the present invention, the necessity of luminance control for raising and lowering the luminance of each area of the backlight is accepted, and when the necessity for luminance control is accepted, the luminance of each area is controlled. The user can select whether or not to enhance the contrast.

  In the present invention, it is possible to automatically switch whether or not to perform the process of increasing or decreasing the luminance of each area of the backlight according to the type of content (color video) viewed by the user. Therefore, it is possible to switch whether or not the contrast is enhanced according to the type of content.

  According to the present invention, it is possible to automatically switch whether or not to perform the process of increasing / decreasing the luminance of each area of the backlight according to the device that is the source of the color video signal to be displayed. Therefore, it is possible to switch whether or not the contrast is enhanced for each input source (device) selected by the user.

  According to the present invention, it is possible to realize a vivid image even in a high-luminance region while increasing the contrast.

It is the block diagram which showed one structural example of the principal part of the liquid crystal television which concerns on this invention. It is explanatory drawing which showed one structural example of the backlight typically. It is a graph for demonstrating the process by a contrast emphasis part. It is explanatory drawing which showed the area control example of the backlight typically. It is the flowchart which showed the process sequence of the backlight area control part. FIG. 10 is a block diagram illustrating a configuration example of a main part of a liquid crystal television according to a second embodiment.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. The liquid crystal television according to the present embodiment displays a color video based on a color video signal input from the outside. The color video signal may be a television broadcast video signal, a video signal read from a recording medium such as a BD (Blu-ray Disc), or a video signal input via a network. There may be.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration example of a main part of a liquid crystal television according to the present invention.
The liquid crystal television (liquid crystal display device) according to the first embodiment includes an input signal switching unit 11, a video processing unit 12, a panel driving unit 13, a liquid crystal panel 14, a backlight area control unit 15, a backlight driving unit 16, and a backlight. 17 etc. In addition, the liquid crystal television of the first embodiment has a tuner (video receiving unit) (not shown).

  The liquid crystal panel 14 is formed by sealing liquid crystal between two substantially rectangular glass substrates that are opposed to each other with a spacer interposed therebetween. Red (R) and green (G) are formed on the opposite surface of the front glass substrate. In addition, a blue (B) primary color filter and a counter electrode are arranged. Scanning lines in the horizontal direction and signal lines in the vertical direction are arranged in a matrix on the opposite surface of the glass substrate on the back side, and a liquid crystal portion corresponding to each pixel is located at the intersection of the scanning lines and the signal lines. An active element for applying a voltage to the TFT, for example, a TFT (Thin Film Transistor) and a pixel electrode are provided. The gate electrode of each TFT is connected to the scanning line, and the source electrode is connected to the signal line. In addition, a polarizing film (not shown) is arranged outside each glass substrate so that the light from the backlight is transmitted with the TFT turned off.

The panel driving unit 13 includes a scanning signal driving circuit connected to the scanning lines of the liquid crystal panel 14 and a signal electrode driving circuit connected to the signal lines. The scanning signal driving circuit is constituted by, for example, a shift register circuit, and sequentially applies the scanning signal to each scanning line to turn on the gates of the TFTs arranged in the horizontal direction. The signal electrode drive circuit is composed of, for example, a shift register circuit and a sample hold circuit, and outputs red, green and blue signals to each signal line. The signal is applied to the drain or source of the TFT gates arranged in the vertical direction.
When the scanning signal driving circuit applies a scanning signal to one scanning line, the horizontal TFTs are turned on all at once, while the signal electrode driving circuit displays red, green and blue color images for one horizontal line. By applying such a signal to the signal line, information relating to the color image can be written to the intersection pixel of the scanning line and the signal line. By sequentially scanning this in the vertical direction, the voltages of the signals relating to the red, green and blue color images are applied to the pixel electrodes corresponding to all the pixels of the liquid crystal panel 14. Since the amount of light transmitted through the liquid crystal layer varies depending on the voltage applied to the pixel electrode, the amount of light transmitted through the backlight 17 is controlled by the magnitude of the signal related to the color image. The three colors of light transmitted through the red, green, and blue pixel filters are displayed to the viewer as a full-color video by the principle of additive color mixing.

The backlight 17 is provided on the back side of the liquid crystal panel 14. The backlight 17 includes a flat dish-shaped backlight chassis, a reflective sheet disposed on the backlight chassis, and a plurality of light sources. FIG. 2 is an explanatory diagram schematically showing a configuration example of the backlight 17. The backlight 17 is entirely divided into a plurality of rectangular areas 170, and each area 170 has three colors, a red (R) LED 17R, a green (G) LED 17G, and a blue (B) LED 17B. An LED (Light-Emitting Diode) is provided. When the plurality of LEDs provided in a two-dimensional shape emit light, the backlight 17 emits light in a planar shape. In FIG. 2, four LEDs 17R, 17G, and 17B are provided in each area 170, but the number is not limited to four. The backlight 17 is controlled to emit light for each area 170. By using such a backlight 17, not only the light emission rate is raised or lowered for each area 170, but also the luminance of the LEDs 17 R, 17 G, and 17 B in each area 170 can be controlled.
An optical sheet for uniformly diffusing light from the backlight 17 and making it incident on the liquid crystal panel 14 is disposed on the front side of the backlight 17.

  Based on the control signal from the backlight area control unit 15, the backlight drive unit 16 has a red LED (R-LED) 17 R, a green LED (G-LED) 17 G, and a blue LED (B -LED) Controls the light emission of 17B. The backlight drive unit (backlight control unit) 16 controls the luminance (light emission rate) of each of the LEDs 17R, 17G, and 17B for each area 170 of the backlight 17.

The input signal switching unit 11 has a plurality of input terminals, and a tuner is connected to one input terminal. Further, external devices such as a BD recorder, a hard disk recorder, a digital still camera, a digital video camera, a game machine, a PC (Personal Computer), and a portable terminal can be connected to the other input terminals. Note that the BD recorder and the hard disk recorder may be integrated.
The input signal switching unit 11 selects an input terminal to which either a tuner or an external device is connected as an input source of the video signal, and gives the video signal input through the selected input terminal to the video processing unit 12. .

For example, the liquid crystal television of Embodiment 1 is based on a reception unit (not shown) that receives an infrared remote operation signal transmitted from a remote operation device operated by a user, and a signal received by the reception unit. And a control unit (not shown) for controlling the operation of each unit constituting the liquid crystal television.
When a user wants to watch a video signal from a television broadcast on a liquid crystal television or to play a video signal recorded on any external device on a liquid crystal television, the user uses a remote control device to instruct that effect. To do. When the user instructs viewing of a television broadcast signal, the control unit gives an instruction to select a video signal from the tuner to the input signal switching unit 11. In addition, when the user instructs reproduction processing of any external device, the control unit gives an instruction to select a video signal from the selected external device to the input signal switching unit 11. As a result, the video signal selected by the user (the television broadcast signal or the video signal from the external device) is appropriately switched by the input signal switching unit 11 and given to the subsequent stage.

The video processing unit 12 performs various kinds of signal processing on the video signal given from the input signal switching unit 11 and, based on the input color video signal, signals indicating red, green, and blue relating to the color video. get. The video processing unit 12 performs processing such as processing for generating RGB signals, digital conversion processing, three-dimensional Y / C separation processing, color space conversion processing, scaling processing, color correction processing, synchronization detection processing, and gamma correction processing, for example. Do as appropriate.
The video processing unit 12 gives the obtained signal to the panel drive unit 13 and the backlight area control unit 15. Therefore, the panel driving unit 13 drives the liquid crystal panel 14 based on the signal given from the video processing unit 12.

  The backlight area control unit 15 determines the luminance (light emission rate) of the LEDs 17R, 17G, and 17B in each area 170 of the backlight 17 based on the red, green, and blue signals provided from the video processing unit 12. . Specifically, the backlight area control unit 15 has, for each region in the liquid crystal panel 14 illuminated by each area 170 of the backlight 17, a gradation value (for example, maximum gradation value) of an image displayed in each region. Based on the above, the luminance of each LED 17R, 17G, 17B in each area 170 is determined. Note that the backlight area control unit 15 controls the LEDs 17R, 17G, and 17B in each area 170 to emit light with similar brightness and emit white light.

  In addition, the backlight area control unit 15 includes a contrast enhancement unit 151, a high luminance region detection unit 152, and an LED luminance determination unit 153. The contrast enhancement unit (brightness control unit) 151 performs a process of lowering the luminance of the low-brightness area 170 and increasing the luminance of the high-brightness area 170 based on the video of each region of the liquid crystal panel 14 corresponding to each area 170. Do. Thereby, an image with enhanced contrast is obtained. Note that the contrast enhancement unit 151 may convert each luminance using a look-up table (LUT) that stores the relationship between each luminance before conversion and each luminance after conversion. Each luminance may be converted based on the function. The contrast emphasizing unit 151 increases or decreases the luminance of the LEDs 17R, 17G, and 17B of each area 170 for each area 170 whose luminance is increased or decreased.

  FIG. 3 is a chart for explaining processing by the contrast emphasizing unit 151. In the chart shown in FIG. 3, the horizontal axis represents IRE indicating the luminance level of the video, and the vertical axis represents the degree of change in IRE before and after processing by the contrast emphasizing unit 151. As shown in the chart of FIG. 3, the processing by the contrast enhancement unit 151 reduces the luminance in the low luminance area 170 and increases the luminance in the high luminance area 170.

  The high-intensity region detection unit (luminance determination unit) 152 detects an area 170 (hereinafter referred to as a high-intensity region) whose luminance is equal to or higher than a predetermined value for each area 170 whose luminance has been changed by the contrast enhancement unit 151. Since the processing contents performed by the contrast emphasizing unit 151 can be grasped in advance, the high luminance area detecting unit 152 is not based on the luminance of each area 170 after the processing by the contrast emphasizing unit 151 but based on the signal from the video processing unit 12. The area 170 that is a high-luminance region may be detected based on the luminance of the area 170. For example, in the chart shown in FIG. 3, the high-intensity region detection unit 152 detects an area 170 in which the IRE before processing by the contrast enhancement unit 151 is 70 or more as a high-intensity region.

  The LED luminance determination unit 153 further changes the luminances of the LEDs 17R, 17G, and 17B in the area 170 for the area 170 detected as a high luminance region by the high luminance region detection unit 152. Specifically, the LED brightness determination unit 153 displays the light emission rates of the LEDs 17R, 17G, and 17B in the area 170 detected as the high brightness area in the area of the liquid crystal panel 14 corresponding to each area 170. Change to the ratio of each color. For example, assuming that each color is expressed with 256 gradations, and the red, green, and blue gradation values of the video are 230, 205, and 25, respectively, the LED brightness determination unit 153 includes the LEDs 17R, 17G, The light emission rate of 17B is 90%, 80%, and 10%.

  The backlight area control unit 15 performs processing by the contrast emphasizing unit 151 and the LED luminance determining unit 153, and returns a control signal indicating the luminance (light emission rate) of each of the LEDs 17 R, 17 G, and 17 B for each area 170 of the backlight 17. This is given to the light driving unit 16.

  FIG. 4 is an explanatory view schematically showing an example of area control of the backlight 17. The image shown in FIG. 4 is an image in which the red sun (sunset) is above the green mountain, the blue lake is at the foot of the mountain (below the image), and the sunset is reflected in the lake. In the example shown in FIG. 4, the area is divided into 8 × 4 32 areas, and the brightness of each of the LEDs 17R, 17G, and 17B is controlled for each area 170. The number of areas 170 into which the backlight 17 is divided is not limited to 32. In the image shown in FIG. 4, for example, in the region R1 displaying sunset or the region R2 displaying mountains, the gradation value of red or green is high, so that it is likely to be a high luminance region. The luminance ratio of the 170 LEDs 17R, 17G, and 17B is controlled to the gradation value ratio of each color of the video.

When processing for enhancing contrast, such as processing by the contrast emphasizing unit 151, is performed, there arises a problem that the color becomes light in a high luminance region. However, as described above, the color of the high luminance region can be darkened by setting the luminance ratio of the LEDs 17R, 17G, and 17B of each area 170 to the ratio of each color of the video. Note that the area 170 other than the high-luminance area is an image with enhanced contrast.
In the backlight area control unit 15, the processing by the contrast enhancement unit 151, the high luminance region detection unit 152, and the LED luminance determination unit 153 is performed by, for example, a user setting a predetermined display mode via a remote control device, It is executed only when the reception unit (necessity reception unit) receives the display mode. The display mode in which the processing by the contrast enhancement unit 151, the high luminance area detection unit 152, and the LED luminance determination unit 153 is executed is, for example, a dynamic mode.

  FIG. 5 is a flowchart showing a processing procedure of the backlight area control unit 15. Based on an instruction from the control unit, the backlight area control unit 15 determines whether or not to execute the process by the contrast enhancement unit 151 (S11), and determines that the process by the contrast enhancement unit 151 is not to be executed ( S11: NO), the process ends. In this case, the backlight area control unit 15 determines the luminance of each of the LEDs 17R, 17G, and 17B in each area 170 of the backlight 17 based on the signal given from the video processing unit 12, and performs control indicating the determined luminance. A signal is given to the backlight driving unit 16.

  When it is determined that the process by the contrast enhancement unit 151 is to be executed (S11: YES), the backlight area control unit 15 executes the process by the contrast enhancement unit 151 (S12). Thereby, based on the image | video of each area | region of the liquid crystal panel 14, the brightness | luminance of the low brightness area 170 is lowered | hung and the brightness | luminance of the high brightness area 170 is raised. The backlight area control unit 15 determines whether or not each area 170 of the backlight 17 is a high luminance region having a luminance equal to or higher than a predetermined value (S13).

  When it is determined that the area is a high brightness area (13: YES), the backlight area control unit 15 displays the ratio of the brightness of the LEDs 17R, 17G, and 17B in this area 170 in the corresponding area of the liquid crystal panel 14. (S14), and the process ends. If it is determined that the region is not a high luminance region (S13: NO), the backlight area control unit 15 skips the process of step S14. The backlight area control unit 15 provides the backlight drive unit 16 with a control signal indicating the luminance of the LEDs 17R, 17G, and 17B in each area 170 processed by the contrast enhancement unit 151 and the LED luminance determination unit 153.

  In the first embodiment, the contrast emphasis unit 151 increases the sense of contrast, and when the contrast is enhanced, the problem that the color becomes thin in the high luminance region is solved, and the high luminance region is vivid. Realize video. In addition, since it is possible to switch whether or not the processing by the contrast emphasizing unit 151 is executed in accordance with the display mode setting by the user, unnecessary contrast emphasizing processing is not performed. For example, when contrast is enhanced for a video signal of a movie, the video may be contrary to the directors intention, but the contrast enhancement processing is not performed for such a video signal. As described above, even when the contrast enhancement process is performed, it is not necessary to consider the problem that the color becomes thin in the high luminance region, so that the system can be configured simply.

(Embodiment 2)
FIG. 6 is a block diagram illustrating a configuration example of a main part of the liquid crystal television according to the second embodiment. In addition to the input signal switching unit 11, the video processing unit 12, the panel driving unit 13, the liquid crystal panel 14, the backlight area control unit 15, the backlight driving unit 16, and the backlight 17, the liquid crystal television of the second embodiment is provided. A content detection unit 18 is included. In addition, about the structure similar to the above-mentioned Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The content detection unit (determination unit) 18 detects the genre (type) as the content of the video signal based on the video signal given from the input signal switching unit 11. For example, when content information (genre information) is added to a television broadcast signal, the content detection unit 18 can acquire content information from the input video signal and specify the genre of the video signal. Examples of the content genre include movies, sports, news, and variety. The content detection unit 18 notifies the backlight area control unit 15 of the identified genre. The content detection unit 18 also gives the specified genre to a control unit (not shown), and the control unit controls the operation of each unit of the liquid crystal television based on the genre given from the content detection unit 18.

  Whether the backlight area control unit 15 according to the second embodiment performs processing by the contrast enhancement unit 151, the high luminance region detection unit 152, and the LED luminance determination unit 153 based on the genre notified from the content detection unit 18. Switch between no. For example, when the genre of the video signal is other than a movie, the backlight area control unit 15 executes processing by the contrast enhancement unit 151, the high luminance area detection unit 152, and the LED luminance determination unit 153. Note that the genre for executing the processing by the contrast emphasizing unit 151, the high luminance region detecting unit 152, and the LED luminance determining unit 153 is not limited to a genre other than a movie.

  The backlight area control unit 15 according to the second embodiment performs the same process as the process described with reference to FIG. 5 in the first embodiment, performs the contrast enhancement process according to the genre of the video signal, Processing for changing the luminance of the LEDs 17R, 17G, and 17B in the area 170 that has become a high luminance region when the contrast enhancement processing is performed is performed. In step S11 of the flowchart shown in FIG. 5, the backlight area control unit 15 according to the second embodiment executes the process by the contrast enhancement unit 151 based on the genre notified from the content detection unit 13. Judge whether or not. Other processes are the same as those described in the first embodiment.

  By the above process, whether or not to perform the contrast enhancement process can be automatically switched according to the genre of the video signal viewed by the user. Further, when the contrast is enhanced, the luminance ratio of the LEDs 17R, 17G, and 17B of each area 170 that becomes the high luminance area is changed to the ratio of each color of the video, so that a colorful image can be obtained even in the high luminance area. Can be displayed.

As described above, the liquid crystal television of the second embodiment is configured to switch the processing by the backlight area control unit 15 according to the genre of the video signal. In addition to this, processing by the contrast enhancement unit 151, the high luminance region detection unit 152, and the LED luminance determination unit 153 is performed in accordance with the input source (transmission source) device of the video signal input via the input signal switching unit 11. Whether to execute or not may be switched.
The backlight area control unit 15 having such a configuration is processed by the contrast enhancement unit 151 according to the input source device of the video signal switched by the input signal switching unit 11 in step S11 of the flowchart shown in FIG. It is determined whether or not to execute. Other processes are the same as those described in the first embodiment.

For example, in many cases, a video signal reproduced from a BD is a movie video signal, and when the input source device is a BD recorder, the processing by the contrast emphasizing unit 151 is not performed, thereby eliminating unnecessary contrast. Execution of the enhancement process is suppressed.
With the above-described processing, whether or not to perform the contrast enhancement processing can be automatically switched according to the external device that the user wants to reproduce. In addition, when contrast is enhanced, a vivid image can be displayed even in a high luminance region.

  The embodiments disclosed herein are illustrative in all respects and should not be considered as restrictive. In addition to liquid crystal televisions including playback devices such as tuners and BDs, liquid crystal televisions include those that input video signals from a personal computer or the like from the outside. That is, the scope of the present invention is not limited to the above-described meaning, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

DESCRIPTION OF SYMBOLS 11 Input signal switching part 12 Image processing part 13 Panel drive part 14 Liquid crystal panel 15 Backlight area control part 16 Backlight drive part (backlight control part)
17 Backlight 18 Content detection unit (determination unit)
151 Contrast enhancement unit (luminance control unit)
152 High Brightness Area Detection Unit (Luminance Determination Unit)
153 LED brightness determination unit (high brightness area control unit)
17R R-LED (light source)
17G G-LED (light source)
17B B-LED (light source)

Claims (6)

A liquid crystal panel having a color filter of a plurality of colors, a backlight having a plurality of color light sources respectively irradiating light of colors corresponding to the color filter on a plane facing the liquid crystal panel, and each of the light sources of the backlight In a liquid crystal display device that includes a backlight control unit that controls the luminance for each area obtained by dividing the light source into a plurality of areas, and displays a color video based on an input color video signal.
A luminance control unit that raises or lowers the luminance of each area according to the luminance based on a color video signal displayed in each region where the light source of each area of the backlight emits light in the liquid crystal panel;
A luminance determination unit that determines whether or not the luminance of each area that has been moved up and down by the luminance control unit is a predetermined value or more;
A high-luminance area control unit that changes a luminance ratio of each light source in an area where the luminance is equal to or greater than a predetermined value so as to be a ratio of each color of a color image displayed in the corresponding area. Display device.   2. The liquid crystal display device according to claim 1, wherein the luminance control unit performs a process of lowering the luminance of the low luminance area and increasing the luminance of the high luminance area. A necessity acceptance unit for accepting necessity of luminance control of each area by the luminance control unit;
The brightness control unit is configured to perform a process of controlling the brightness of each area when the necessity reception unit receives the necessity of brightness control. The liquid crystal display device described. A determination unit for determining a type of the color image;
The said brightness | luminance control part is made to perform the process which controls the brightness | luminance of each area according to the determination result of the said determination part. The Claim 1 characterized by the above-mentioned. Liquid crystal display device. A determination unit for determining a device from which the color video signal is transmitted;
The said brightness | luminance control part is made to perform the process which controls the brightness | luminance of each area according to the determination result of the said determination part. The Claim 1 characterized by the above-mentioned. Liquid crystal display device. A video receiver for receiving a color video signal;
A liquid crystal display device according to any one of claims 1 to 5, and
The liquid crystal television, wherein the liquid crystal display device displays a color video based on a color video signal received by the video receiver.

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