JP2013225035A - Image display device and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device suppressing luminance unevenness of the image display device and having an excellent display characteristic and the control method.SOLUTION: Luminance of a display element 4 is measured at each temperature. A correction value table at each temperature, which includes a luminance correction value of the display element 4 determined according to each temperature, is prepared. Temperature information is periodically read out for the unit of a display panel 3 including a plurality of display elements 4 and the temperature is monitored. Every time the temperature of the display panel 3 changes, a luminance correction value at a corresponding temperature is read out from the correction value table at each temperature. The luminance of the display element 4 in the display panel 3 is corrected for each unit of the display panel 3 using the luminance correction value.

Description

  The present invention relates to a video display device in which display elements such as LEDs and fluorescent display tubes are arranged as pixels to form a screen, and a control method therefor.

  The conventional lighting method of the LED display unit is disclosed to store data for aligning luminance unevenness of individual LEDs and correct the light emission luminance. Further, it is also disclosed that correction is performed according to the temperature of the place where the display is installed (see, for example, Patent Document 1).

Further, it has been shown that a conventional video display device has memory means for storing correction data for correcting variations in light emission luminance of display elements (see, for example, Patent Document 2).
Furthermore, it has been shown that the conventional full-color display device detects the temperature of each LED of the display unit with a temperature sensor in color misregistration correction (see, for example, Patent Document 3).

Japanese Patent No. 2950178 Japanese Patent Laid-Open No. 11-344949 JP 2000-112429 A

In the conventional technique, when all the pixels are driven under the same conditions, the display on the screen is caused by the variation in luminous intensity depending on the individual difference of each display element (the same for the light emitting display element and the light emitting element). There was a problem that it was not uniform and the entire screen looked rough. In order to prevent such problems and absorb variations in the luminous intensity of each display element, the driving means for driving the display element calculates the optimum light emission luminance of each display element.
A conventional video display apparatus performs correction control based on correction data prepared in advance and stored in a memory, thereby eliminating luminance unevenness as a whole and improving video quality.
However, the display element generates heat when it is turned on and the temperature rises. The display element has a characteristic that the luminance decreases as the temperature rises. Due to this characteristic, when display is performed with correction data acquired when the temperature is low, there is a problem that the brightness of the display element at a location where the temperature is high in the video display device is lowered and the screen display is perceived as uneven display. .

  The present invention has been made to solve such problems, and monitors the temperature in units of display panels constituting the video display device, and uses the brightness correction value data of the display element suitable for each temperature, An object of the present invention is to provide an image display apparatus and a control method thereof that can reduce luminance unevenness due to temperature unevenness in a display screen by performing correction control.

A video display apparatus according to the present invention includes a display panel in which a plurality of display elements are arranged, a display module including an assembly of the display panels, a temperature measurement unit that measures each temperature in the display panel, and the temperature measurement unit In accordance with the temperature of each display panel measured in step (b), a luminance correction unit that corrects the luminance of the display element for each display panel is provided, and the luminance correction unit calculates a luminance correction value corresponding to the temperature of the display element. The brightness correction value corresponding to the temperature measured by the correction value storage unit to be stored and the temperature measurement unit is read from the correction value storage unit, and the brightness of the display element in each of the display panels is read as the brightness correction value. And an arithmetic controller for controlling each display panel unit.

  The video display device control method according to the present invention is a control method for controlling a video display device comprising a display module comprising a collection of display panels in which a plurality of display elements are arranged. A step of creating a correction value table at each temperature comprising the brightness correction value of the display element obtained according to each temperature, and periodically reading the temperature information for each display panel and monitoring the temperature Each time the temperature of the display panel changes, the brightness correction value of the corresponding temperature is read from the correction value table at each temperature, and the brightness of the display element in the display panel is read using the brightness correction value. Is included for each display panel unit.

  According to the video display apparatus according to the present invention, the brightness correction unit can control and control the brightness of the plurality of display elements according to the temperature for each display panel. The effect that a device can be obtained is obtained.

  According to the control method of the video display apparatus according to the present invention, the brightness of the plurality of display elements can be corrected and controlled according to the temperature for each display panel, so that the image quality of the video display apparatus is good without uneven brightness. The effect that the image quality can be improved is obtained.

It is a schematic block diagram of the video display apparatus by Embodiment 1 of this invention. It is a figure which shows the example of a correction value table in each temperature used for the brightness | luminance correction | amendment of the display element by Embodiment 1 of this invention. It is a figure which shows the temperature information example of each display panel which concerns on Embodiment 1 of this invention. It is a figure which shows the example of correction value data set to each display panel which concerns on Embodiment 1 of this invention.

Embodiment 1 FIG.
A video display apparatus and a control method thereof according to Embodiment 1 of the present invention will be described with reference to FIGS. A video display device according to the present invention includes a display panel in which a plurality of display elements are arranged, a display module composed of an assembly of the display panels, a temperature measurement unit (temperature sensor) that measures each temperature in the display panel, and temperature measurement A luminance correction unit (control unit) that corrects the luminance of the display element for each display panel according to the temperature of each display panel measured by the unit, and the luminance correction unit sets a luminance correction value corresponding to the temperature of the display element. The correction value storage unit to be stored and the luminance correction value corresponding to the temperature measured by the temperature measurement unit are read from the correction value storage unit, and the luminance of the display element in each display panel is displayed based on the luminance correction value. An arithmetic controller that controls each unit is included.
In the description of the invention, the terms luminance (emission luminance) and luminous intensity (emission luminous intensity) are used. However, the unit of luminance is candela per square meter and indicates the brightness per unit area. The unit is candela, which means the intensity of light emitted from the light source (all brightness). Therefore, luminance is shown as correction value data used for performing correction control.

FIG. 1 is a schematic configuration diagram for explaining a basic configuration of a video display apparatus according to Embodiment 1 of the present invention. In FIG. 1, the video display apparatus 1 has a plurality of display modules 2 arranged in a matrix. The display module 2 is configured by arranging and connecting a plurality of display panels 3 in a matrix and configured with a control unit (corresponding to a luminance correction unit) 8, and the display panel 3 is configured by a plurality of display panels 3. The elements 4 are arranged and connected in a matrix to constitute a video display screen. FIG. 2 shows an example of a correction value table at each temperature, which is information relating to the luminance correction of the display element 4, and is a chart showing the luminance correction value of the display element 4 that changes depending on the temperature. FIG. 3 is a diagram illustrating an example of temperature information of each display panel in which the temperature measured for each display panel 3 of the video display device 1 including the plurality of display panels 3 is exemplified. 4 is a diagram showing an example of correction value data set in each display panel 3 when the temperature of the display panel 3 in FIG. 3 is applied to the correction value table in FIG. This is applied to all display elements 4.

  The display panel 3 includes a display element 4 composed of a plurality of (for example, 16 dots × 16 dots) LEDs and light emitting display elements (pixels) such as a fluorescent display tube, and a display element driver 5 for driving the display element 4. And a temperature sensor (corresponding to a temperature measurement unit) that measures the temperatures of the nonvolatile memory 6 that stores correction data used to correct the variation in luminous intensity for each pixel of the display element 4 and the display panel 3, and acquires the values. .) 7 is provided. The correction data has a data amount corresponding to the number of pixels included in each display panel 3 and each temperature.

The control unit (luminance correction unit) 8 includes a microcomputer 9, a correction value storage unit 10, a video memory 11, and an arithmetic controller 12.
The microcomputer 9 receives a command from the host and performs overall control of the display function in the display module 2, transmission / reception of correction data with the nonvolatile memory 6 in the display panel 3, and communication control of the temperature sensor 7.

  The correction value storage unit 10 includes a RAM, and stores correction data having a data amount corresponding to the total number of pixels in the display module 2. The correction data temporarily stored in the correction value storage unit 10 is data that is read from the nonvolatile memory 6 and developed by the microcomputer 9 via the arithmetic controller 12. Luminous intensity correction for absorbing variations in luminous intensity of the display element 4 is performed over all pixels, that is, all display elements 4. That is, all the display panels 3 have their respective nonvolatile memories 6, and the correction data stored in each nonvolatile memory 6 is developed in all the correction value storage units 10 in the display panel 3. The

The video memory 11 includes a RAM, and is an upper control unit in which video signal data having a data amount corresponding to the total number of pixels included in the video display device 1, that is, the display module 2, is arranged outside the video display device 1. Is input via the arithmetic controller 12 and the video signal data is temporarily stored.
The arithmetic controller 12 uses the video signal data stored in the video memory 11 and the correction data stored in the correction value storage unit 10 for all of the correction data stored on the display panel 3 in order to absorb variations in the luminous intensity of the display element 4. The display element 4 is operated so that the luminous intensity of the display element 4 is constant, and driver drive data for driving the display element driver 5 is generated.

Next, an example of calculation for absorbing the variation in the luminous intensity depending on the individual difference of the display elements 4 will be described. For example, in the A element with the luminous intensity a and the B element with the luminous intensity b, when the target luminous intensity is c, the A element is 1.5 times the target, and the B element is 1/2 the target, 1 / 1.5 correction needs to be performed, and the B element needs to be corrected twice. If the correction value data Xa of the A element and the correction value data Xb of the B element are 10-bit (1024 maximum) operation data and 512 is set to a condition of 1 time correction, correction value data satisfying the following equation can be obtained.
c = a × Xa / 512
c = b × Xb / 512
The correction value data is calculated with Xa = 341 and Xb = 1024. The above is the calculation method of the correction value data for correcting the variation in the luminous intensity depending on the individual difference of the display elements 4. However, the luminance correction of the display element 4 performed depending on the temperature for each unit of the display panel 3 is the same. The calculation method is used.

  The arithmetic controller 12 also corrects the luminance of the display element 4 in accordance with the temperature of each display panel 3 in addition to the correction for absorbing the variation in luminous intensity due to the individual difference of the display elements 4 as described above. It is. The arithmetic controller 12 reads out only the data for driving the desired display element 4 from the video signal data and the correction data at a synchronized timing, and performs an operation on each read data to obtain a desired value. Driver drive data for driving the display element 4 is generated and transmitted to one of the corresponding display panels 3. This read operation and calculation operation are finally performed on all the display elements 4 by sequentially advancing the memory addresses of the video memory 11 and the correction value storage unit 10 corresponding to the display elements 4. Thereby, display driving is performed on all display elements 4 included in all display panels 3 in the display module 2 constituting the video display device 1.

The control method of the video display device 1 configured as described above will be described in more detail.
First, at the stage of creating a correction value table at each temperature as shown in FIG. 2, a target luminous intensity for each display panel 3 is determined in advance. For example, the luminous intensity when the display panel 3 is 20 ° C. is used as a reference.
Next, the luminous intensity of the display panel 3 at each temperature is measured.
From the measured measurement data of the luminous intensity of the display panel 3, a luminance correction value that becomes the target luminous intensity is calculated, and correction value table data at each temperature is created.
It is also possible to create a correction value table by changing the correction value from the luminance correction value to the luminous intensity correction value and use it for correction control.

Next, the correction value table at each temperature is stored in the correction value storage unit 10 of the video display device 1 by the microcomputer 9 when the power is turned on.
Next, the arithmetic controller 12 that has received the video signal data instructs the microcomputer 9 to detect the temperature of the display panel 3 by the temperature sensor 7.
Next, the arithmetic controller 12 compares the temperature of the display element 4 with the correction value table to obtain an appropriate luminance correction value. The appropriate brightness correction value is obtained every time the temperature of the display panel 3 monitored by the temperature sensor 7 changes, and the arithmetic controller 12 corrects the video display data to make the display panel 3 have an appropriate luminous intensity. To display.

The arithmetic controller 12 corrects the variation with the correction value data Xa and Xb of the variation correction of the luminous intensity based on the individual differences of the display elements 4 described above, and further uses the correction value table for each temperature to correct the temperature. Thus, video data is created, and the display characteristics of the video display device 1 are prevented from deteriorating due to individual differences of the display elements 4 and temperature fluctuations.
Needless to say, if there is a factor that needs to be corrected and can be controlled in addition to the individual difference and temperature fluctuation of the display element 4, it is effective to perform correction control together.

For example, when the correction value table at each temperature as shown in FIG. 2 is obtained, and the temperatures of the plurality of display panels 3 as the video display units are different for each display panel 3 as shown in FIG. Since the temperature information of (display panel) A is 31 ° C., correction value data 0.79 of 31 to 35 ° C. is set in panel A from the correction value table at each temperature in FIG. Similarly, the correction value data of each display panel B to I is set, and the luminance correction value of each display panel A to I is set as shown in FIG. Based on the data of FIG. 4, the luminance of the display element 4 that varies with temperature is corrected in units of the display panel 3, thereby reducing the luminance deterioration caused by the temperature rise of the display element 4 and making the display surface uniform. It is possible to display with brightness, and display unevenness of the video display device 1 can be reduced.
For example, when the temperature of the installation location of the video display device 1 is measured and the temperature correction control of the display elements 4 in the entire screen is uniformly performed based on the measured temperature, the brightness unevenness due to the temperature unevenness of the screen. However, in the present invention, since the temperature of the display panel 3 itself is measured and the temperature correction control can be performed for each display panel 3, it is possible to improve the display characteristics of the entire display screen.
In the present invention, the embodiments can be appropriately modified and omitted within the scope of the invention.

DESCRIPTION OF SYMBOLS 1 Video display apparatus 2 Display module 3 Display panel 4 Display element 5 Display element driver 6 Non-volatile memory 7 Temperature sensor (temperature measurement part)
8 Control unit (luminance correction unit)
9 Microcomputer 10 Correction value storage unit 11 Video memory 12 Arithmetic controller.

Claims (2)

  A display panel in which a plurality of display elements are arranged, a display module composed of an assembly of the display panels, a temperature measuring unit for measuring each temperature in the display panel, and the temperature of each display panel measured by the temperature measuring unit And a luminance correction unit that corrects the luminance of the display element for each display panel, the luminance correction unit including a correction value storage unit that stores a luminance correction value corresponding to the temperature of the display element, and The luminance correction value corresponding to the temperature measured by the temperature measurement unit is read from the correction value storage unit, and the luminance of the display element in each display panel is determined for each display panel unit based on the luminance correction value. A video display device comprising an arithmetic controller for controlling the video display.   In a control method for controlling a video display device provided with a display module made up of an assembly of display panels in which a plurality of display elements are arranged, the brightness at each temperature of the display element is measured and determined according to each temperature A step of creating a correction value table at each temperature, which includes brightness correction values of the display element, a step of periodically reading temperature information in units of the display panel and monitoring the temperature, and whenever the temperature of the display panel changes Reading the luminance correction value at the corresponding temperature from the correction value table at each temperature, and correcting the luminance of the display element in the display panel for each display panel using the luminance correction value. Control method of video display device.

Images