JP6469477B2 - Electronic device and display control method - Google Patents

Description

  The present invention relates to an electronic device and a display control method.

  2. Description of the Related Art In electronic devices that display video, for example, display devices, there are display devices that use a liquid crystal display panel and an LED backlight.

  The heat from the LED backlight partially exposes the liquid crystal display panel to a high temperature in relation to the brightness of the image displayed by the liquid crystal display panel.

  The liquid crystal display panel has an operating temperature range in which an image can be displayed. For this reason, for the purpose of use such as a commercial advertisement display device, for example, the display area is divided into several areas based on the brightness of the image displayed on the liquid crystal display panel, and each divided area is divided. In addition, it is necessary to cool so as not to exceed the operating temperature range.

JP 2013-246186 A JP 2011-77005 A

  When cooling each area divided into several areas based on the brightness of the image displayed on the liquid crystal display panel, it is necessary to measure the temperature of each area.

  However, when measuring the temperature for each region, many temperature sensors are required. On the other hand, in order to reduce the number of temperature sensors, a method for predicting the temperature of each region of the liquid crystal display panel based on the displayed image and setting the degree of cooling for each region has not been sufficiently established.

  An object of the present invention is to provide an electronic apparatus and a display control method for displaying an image in a temperature range that does not deviate from an operating temperature range in which an image can be displayed.

The electronic device according to the embodiment includes a display panel having a display surface which is an area for displaying an image, and a region opposite to the display surface for each region obtained by dividing a surface opposite to the display surface of the display panel into a predetermined number. is disposed facing the surface, illuminating means outputs an illumination light for illuminating the image wherein the display surface is displayed, a plurality of locations located at a plurality of positions and a lower end located at the upper end of the display surface of the display panel are arranged respectively, by outputting the cooling air to accompany the display surface, a cooling means for maintaining in the displayable temperature range the temperature of the display surface, and the video signal of the video displayed on the display surface, Based on the temperature for each of the areas detected by a temperature sensor installed inside that detects the temperature at a predetermined position of the illuminating means, the brightness of the image displayed on the display surface is determined by the illuminating means. Lighting value and lighting time Setting means for setting the control, and the video signal of the video displayed on the display surface, the said temperature of each of the areas where the temperature sensor detects, based on the air volume of the cooling air the cooling means outputs And cooling control means for controlling the wind direction.

1 illustrates an example of a display device (electronic device) according to an embodiment. An example of the display panel temperature prediction process part of the display apparatus which concerns on embodiment is shown. An example of the cooling control process part of the display apparatus which concerns on embodiment is shown. An example of the prediction of the temperature rise (temperature distribution) of the light emission area of the backlight of the display apparatus which concerns on embodiment, and the display area of the display surface of an LCD panel is shown. An example of the relationship between the operation | movement of the cooling device of the display apparatus which concerns on embodiment, and the temperature which a temperature sensor detects is shown.

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

  FIG. 1 shows an example of an electronic apparatus according to the embodiment.

  In FIG. 1, a display device (electronic device) 1 can change the amount of light emission for each of an LCD (Liquid Crystal Display) display panel (hereinafter referred to as an LCD panel) 2 for displaying an image and an arbitrary number of divided areas. And an illuminating device (hereinafter referred to as a backlight) 3 for illuminating an image displayed on the LCD panel 2.

  The display device 1 also includes a middle frame 4 that holds the LCD panel 2 and the backlight 3, and a front bezel 5 and a back bezel 6 that sandwich and support the middle frame 4 from the front and rear in the arrangement direction of the LCD panel 2 and the backlight 3. Including. The backlight 3 is substantially held by the back bezel 6 and integrated with the middle frame 4 by connecting the middle frame 4 and the back bezel 6.

  The backlight 3 is substantially held by the back bezel 6, for example, m (m is a positive integer) rows × n (n is a positive integer) columns (in the example of FIG. 1, m = 8 × n = 6). Each region 6a divided into a total of 48)) includes one or more LED (Light Emitting Diode) elements. First to fourth temperature sensors TA, TB, TC, and TD are located at predetermined positions of the backlight 3, for example, at four corners of the middle frame 4 that holds the backlight 3. Note that the first to fourth temperature sensors TA, TB, TC, and TD may be positioned at, for example, the four corners of the LCD panel 2.

  The backlight 3 also includes a reflection sheet 7, a diffusion sheet 8 and an optical sheet 9 between the middle frame 4. The reflection sheet 7 directs the light output from the LED elements in each of the m × n divided areas to the LCD panel 2 side. The diffusion sheet 8 equalizes the luminance in the surface direction of the LCD panel 2 of the light output from individual (m × n) LED elements. The optical sheet 9 homogenizes the wavefront characteristics of the light output from the individual LED elements. The diffusion sheet 8 and the optical sheet 9 may be arranged in reverse order. Further, at least one of the diffusion sheet 8 and the optical sheet 9 may be two or more. The first to fourth temperature sensors TA, TB, TC, and TD may be positioned at, for example, the four corners of the front surface of the reflection sheet 7 (in the assembled state).

  The front bezel 5 is located at a predetermined position of a front surface of the LCD panel 2, that is, a surface (hereinafter simply referred to as a display surface) 2a opposite to the backlight 3 in the front and rear (Z) direction with respect to the LCD panel 2. The display surface 2a is located at a predetermined position in a plane orthogonal to the front-rear direction of the display surface 2a. That is, the front bezel 5 has a predetermined position in the XY plane perpendicular to the front-rear (Z) direction of the LCD panel 2 with respect to the position of the display surface 2a of the LCD panel 2 in the display device 1 in a state where all components are assembled. Set to position.

  A back cover 10 is located on the back surface of the back bezel 6. Further, on the back surface of the back bezel 6, as will be described later with reference to FIGS. 2 to 4, for example, signal processing for holding the display panel temperature prediction processing unit 200, the cooling control processing unit 300, the backlight signal processing unit 400, and the like. The part (circuit board) 11 is located. The circuit board 11 is covered by the back cover 10. Note that a stand that can be used to position the display device 1 at a predetermined position can be attached to the back cover 10.

  Between the display surface 2a of the LCD panel 2 and the front bezel 5, a cooling mechanism 101 for cooling the display surface 2a of the LCD panel 2 and a liquid crystal layer integrated with the display surface 2a is located.

  The cooling mechanism 101 includes a top panel 111, for example, four first to fourth blowers (fans) 112 a to 112 d and a support frame (housing) 113.

  The top panel 111 is arranged so that the cooling air output from the first to fourth fans 112a to 112d follows the display surface 2a of the LCD panel 2 between the display surface 2a of the LCD panel 2 and the front bezel 5. A guiding passage (cooling air passage) 115 is formed. The top panel 111 (and the cooling mechanism 101) may be integrated with the front bezel 5.

  Two first to fourth fans 112a to 112d are located at predetermined positions of the top panel 111 or the support frame 113 (or the front bezel 5), for example, at the upper end and the lower end of the LCD panel 2, respectively. Cooling air is provided (output) to the path 114. When there are four fans, for example, two each may be located on the left and right of the LCD panel 2. Further, when there are two fans, for example, they may be located only at the lower end of the LCD panel 2.

  FIG. 2 illustrates an example of the display panel temperature prediction processing unit.

  The display panel temperature prediction processing unit 200 calculates the maximum value 212 of at least one of the brightness / darkness of the input pixel for each light emitting area of the backlight 3 from the input video signal 211 by the maximum value calculation unit 201 for each area. The multiple-frame moving average filter 202 refers to the maximum value 212 calculated by the area-specific maximum value calculation unit 201 and performs a moving average filter process 213 between a plurality of video frames. That is, the maximum value 212 of at least one of the brightness / darkness of the input video is obtained, and the moving average filter processing 213 is performed between the video frames, so that an arbitrary display area of the LCD panel 2 can be obtained due to the video to be displayed. Video that does not easily rise is extracted so that the temperature does not rise rapidly. As a result, an instantaneous luminance change can be suppressed so that the influence of the temperature change caused by the brightness and color of the displayed video is reduced.

  Next, the limiter setting means 203 compares the signal obtained by the filter processing 213 (hereinafter referred to as SIG-F) with the signal level set for each display area of the backlight 3 (hereinafter referred to as LMT-L). When the value of SIG-F is larger than the value of LMT-L, the limiter control 214 set by the limiter setting means 203 is set so as to enter a standby (hereinafter referred to as FLG-S) state.

  Next, the lighting time of the backlight 3 and the temperature change time of the LCD panel 2 are measured in advance, and the limiter start time setting means 204 performs FLG so that the temperature of the LCD panel 2 does not reach the operating temperature of the limiter control 214. -Set the valid time of S. When the effective time of FLG-S exceeds the set value, a brightness-based limiter control signal (hereinafter referred to as LLCD) is output to limiter control determination means 205.

  Regarding the individual display areas of the LCD panel 2, first, temperature information (hereinafter referred to as TM) obtained from the first to fourth temperature sensors TA, TB, TC and TD installed at predetermined positions around the LCD panel 2. )

  Hereinafter, the temperature information TM obtained from the first to fourth temperature sensors TA, TB, TC and TD and the temperature parameter (hereinafter referred to as TP) set for each area of the LCD panel 2 are used as the temperature parameter setting means 206 for each area. Compare. When the information temperature TM in any display area exceeds the set parameter TP, a limiter control signal (hereinafter referred to as LTEP) is output to the limiter control determination means 205.

  The limiter control determination means 205 outputs a limiter control signal (hereinafter referred to as LVIDEO) for each display area of the LCD panel 2. That is, the limiter control signal LVIDEO is a logic of the limiter control signal LLCD generated based on the video signal 211 and the limiter control signal LTEP generated based on the outputs of the first to fourth temperature sensors TA, TB, TC, and TD. It is obtained by calculating the sum.

  FIG. 3 illustrates an example of the cooling control processing unit.

  The cooling control processing unit 300 outputs the first to fourth cooling fans 112a to 112d toward a display area where the temperature of the front surface (display surface 2a) of the LCD panel 2 exceeds a predetermined temperature and the limiter control 214 is required. The direction of the cooling air and the strength (wind speed) of the cooling air are set. That is, based on the limiter control signal LVIDEO, the cooling control processing unit 300 can provide the cooling air with the above-described wind speed to the display area to be cooled of the LCD panel 2, and the first to fourth cooling fans 112 a to 112 d output The direction 311 of the cooling air to be set is set. The cooling control processing unit 300 also sets the cooling air velocity 312 to be output by each fan according to the distance between the display area to be cooled on the LCD panel 2 and the first to fourth cooling fans 112a to 112d. To do.

  The cooling control processing unit 300 outputs a fan control signal 313 that can provide the set wind direction 311 and wind speed 312 to the first to fourth cooling fans 112a to 112d.

  When any of the first to fourth cooling fans 112a to 112d fails, the cooling control processing unit 300 can perform cooling with the failed fans by the output from the remaining cooling fans. For example, when one of the two fans positioned at the upper and lower ends of the display surface 2a of the LCD panel 2 fails, the cooling wind direction 311 and the wind speed 312 output from the fan positioned opposite to the failed fan are displayed. ,adjust. Note that the failure of any fan can be detected by monitoring the error control means 301 that the fan error signal 314 is input from the fan.

  FIG. 4 shows a prediction example of the temperature rise (temperature distribution) of the light emission area of the backlight and the display area of the display surface of the LCD panel.

  Based on the input video signal 211, the display device 1 performs an optimal angle of view and video correction processing to be displayed on the LCD panel 2 in the video signal processing unit 200, and supplies the image to the LCD panel 2 as an output image signal 411. The backlight control processing unit 400 outputs lighting value data of the LED unit for each divided area of the backlight 3 based on the output image signal 411 from the video signal processing unit 200 and the limiter control signal LVIDEO. The backlight control processing unit 400 calculates the brightness (luminance of illumination light to be output) for each divided area of the backlight 3 and divides the backlight 3 by, for example, a PWM (Pulse Width Modulation) signal. Controls the brightness (luminance of output illumination light) for each area.

  The cooling control processing unit 300 controls the cooling wind direction 311 and the wind speed 312 output from the first to fourth fans 112a to 112d by the fan control signal 313 based on the limiter control signal LVIDEO.

  That is, as shown in FIG. 4, the backlight control processing unit 400 lowers the lighting value 421 of the LED backlight 3 in the area where the limiter control signal LVIDEO is valid, and radiates heat (heat from the LED) that reaches the LCD panel 2. ) Is preferably suppressed. Further, the video signal processing unit 200 compensates for the brightness lost by increasing the video signal level 411 (increasing the white component) of the area where the limiter control signal LVIDEO is effective and decreasing the lighting value 421 of the backlight 3. Is preferred. Further, the video signal processing unit 200 compensates for the brightness lost by increasing the video signal level 411 (increasing the white component) of the area where the limiter control signal LVIDEO is effective and decreasing the lighting value 421 of the backlight 3. Is preferred.

  Note that the backlight control processing unit 400 (fails) when any of the first cooling fan 112a, the second cooling fan 112b, the third cooling fan 112c, and the fourth cooling fan 112d fails. It is preferable to reduce the brightness of the LCD panel 2 by receiving the error signal 314 from the fan via the (error control unit 301).

  FIG. 5 illustrates the relationship between the operation of the cooling device and the temperature detected by the temperature sensor.

  As shown in FIG. 5, four cooling fans (first cooling fan 112a, second cooling fan 112b, third cooling fan 112c, and fourth cooling fan 112d are arranged vertically (in the Y direction). The temperature detection areas of the LCD panel 2 detected by the first to fourth temperature sensors TA, TB, TC and TD installed at the four corners of the backlight 3 are orthogonal to each other. It is divided into four by two straight lines and cooled by cooling air from a cooling fan adjacent to each region.

  Numerical values A1-A5, B1-B5, C1-C5 and D1-D5 in the divided area of the backlight 3 are respectively obtained from first to fourth temperature sensors TA, TB, TC and TD provided at four corners. And the limiter temperature (limiter control) according to the distance from the first to fourth temperature sensors TA, TB, TC, and TD (in the example of FIG. 5, A5, B5, C5, and D5 near the center). Signal LVIDEO) is set low.

  The direction 311 of the cooling air output from each cooling fan 112a-112d is made non-parallel to the Y axis, and the cooling air is collected in the display area of A5, B5, C5 and D5 near the center, and the wind speed 312 is controlled. Thus, it is preferable to control the outputs of the individual fans so that the cooling air reliably reaches the display areas A5, B5, C5, and D5 near the center.

  The display device 1 includes a main control block that controls, for example, a tuner that receives broadcast (TS), a TS separation unit, a display panel temperature prediction processing unit 200, a cooling control processing unit 300, and a backlight signal processing unit 400. Needless to say, a normal digital broadcast can be received and reproduced.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Electronic device) 200 ... Display panel temperature prediction process part, 300 ... Cooling control process part, 400 ... Backlight signal process part.

Claims (5)

A display panel having a display surface which is an area for displaying video;
Illumination light for illuminating an image displayed on the display surface is disposed for each region obtained by dividing the surface opposite to the display surface of the display panel into a predetermined number, facing the surface opposite to the display surface. Lighting means for outputting;
Wherein are respectively disposed at a plurality of locations located at a plurality of positions and a lower end located at the upper end of the display surface of the display panel, by outputting the cooling air to accompany the display surface capable of displaying the temperature of the display surface temperature Cooling means to maintain within range,
Based on the video signal of the video to be displayed on the display surface and the temperature for each of the regions detected by a temperature sensor installed inside that detects the temperature at a predetermined position of the illumination means, the display surface Setting means for setting the brightness of the video to be displayed by controlling the lighting value and lighting time of the lighting means;
Cooling control means for controlling the air volume and direction of the cooling air output from the cooling means based on the video signal of the video displayed on the display surface and the temperature for each of the areas detected by the temperature sensor. When,
An electronic device comprising: The electronic device according to claim 1, wherein the setting unit predicts the temperature of the display surface by calculating a maximum value of a lighting value of the illumination unit for each of the regions used in the temperature prediction of the display surface. The electronic device according to claim 1, wherein the setting unit performs a moving average filter process on a plurality of frames of the video signal after calculating a maximum value of a lighting value of the illumination unit for each region, and suppresses a temperature change of the display surface .   The electronic device according to claim 1, wherein the cooling control unit predicts the temperature for each region according to a distance from the temperature sensor, and sets the direction and amount of the cooling air output by the cooling unit. A display panel having a display surface which is an area for displaying video;
A first step of illuminating an image displayed on the display surface facing the surface opposite to the display surface for each region obtained by dividing the surface opposite to the display surface of the display panel into a predetermined number;
From each of the plurality of locations located at a plurality of positions and a lower end located at the upper end of the display surface of the display panel, by outputting the cooling air to accompany the display surface capable of displaying the temperature of the display surface temperature range A second step of cooling to maintain
The video signal of the image to be displayed on the display surface, and the temperature of each of the areas where the temperature sensor detects that installed inside for detecting the temperature of a predetermined position to illuminate, on the basis of the display on the display surface A third step of setting the brightness of the video by controlling the lighting value and lighting time for illuminating the display surface ;
Based on the video signal of the video to be displayed on the display surface and the temperature for each region detected by the temperature sensor, the air volume and the direction of the cooling air that cools the temperature of the display surface of the display panel A fourth step of controlling
Display control method for electronic equipment having

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