JP2001041852A - Display abnormality-detecting apparatus, and photosensor unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a display abnormality-detecting apparatus for automatically detecting a display abnormality brought about on a display screen of a display apparatus, and further a display abnormality-detecting apparatus which automatically copes with a display abnormality. SOLUTION: A detecting system 20 converts contents displayed to a liquid crystal panel of a display device 10 to electric signals for every pixel by a photosensor part 21. A detecting circuit 23 generates and outputs a detected data S3 and a luminance data S4 from the signals. A comparing circuit 24 compares the detected data S3 between adjacent pixels, and outputs the comparison result as a detection/comparison data S5. A control system 30 decides based on the luminance data S4 and the detect/comparison data S5 whether or not a display abnormality takes place on the liquid crystal panel. When it is decided that the display abnormality takes place, luminance adjustment data generated according to the contents is sent to the display device 10, so that the display abnormality is automatically coped with.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for displaying information on a display screen of a display device in a more preferable state.

[0002]

2. Description of the Related Art At present, a method of displaying information by applying a voltage on a pixel-by-pixel basis (hereinafter referred to as a pixel-based driving method for convenience) is widely used in display devices. LCD and LED
A display, a PDP, an FED, a VFD, an EL display, and the like are display devices adopting such a method. This method has an advantage that the device can be easily made thinner and lighter.

[0003]

In a display device adopting a pixel-by-pixel driving method, a voltage is applied on a pixel-by-pixel basis, so that the display cannot be driven and does not have a desired color or brightness. Display error), or display abnormality such as a difference in color or brightness from the other even when driven under the same conditions. Until now, such display abnormalities,
People were supposed to judge things visually and deal with them.

[0004] However, the display device is not always installed in a place where a person who can determine a display abnormality (hereinafter referred to as a user) can quickly find the display abnormality. For example, a display device adopted as a public display device for transmitting information to the public is often installed in a place invisible from a place where a user is. When the display device is installed in such a place, usually, the user cannot quickly know the occurrence of the display abnormality. This means that information to be transmitted cannot be appropriately transmitted to the public due to display abnormality for a long time. This is highly undesirable. For this reason, it has been desired that the user can quickly and promptly know the occurrence of the display abnormality regardless of the installation location of the display device.

[0005] In the display device, contrast and the like may be reduced due to the influence of external light, for example. Display abnormalities caused by such environmental changes can usually be dealt with without replacing parts. From this, it is considered that it is desirable to be able to automatically deal with such display abnormalities from the viewpoint of improving convenience.

It is a first object of the present invention to provide a display abnormality detecting device for automatically detecting a display abnormality occurring on a display screen of a display device. A second object of the present invention is to provide a display abnormality detection device that automatically responds to a display abnormality that has occurred on the display screen.

[0007]

The first and second aspects of the present invention are described.
The display abnormality detecting device according to the above aspect is based on the premise that a display abnormality in displaying information generated on the display screen of the display device is detected, and includes the following units.

According to a first aspect of the present invention, there is provided a display abnormality detecting device, comprising: display content detecting means for detecting display content of a display screen being driven by a display device; Display abnormality detecting means for detecting a display abnormality.

A display abnormality detecting device according to a second aspect is characterized in that, in addition to the configuration of the first aspect, when the display abnormality detecting means detects a display abnormality, the display device detects the abnormality according to the content of the display abnormality. There is further provided driving condition adjusting means for adjusting conditions for driving the display screen.

In the first and second embodiments, the display content detecting means detects the display content on a pixel-by-pixel basis on the display screen, and the display error detecting means detects the display error on a pixel-by-pixel basis. It is desirable to detect Further, when the display device is a liquid crystal display device, the display content detection means detects the amount of light of a backlight mounted on the liquid crystal display device as display content, and the display abnormality detection means includes a display content detection means. It is desirable to detect a display abnormality based on the detected light amount of the backlight. At this time, it is desirable that the driving condition adjusting means adjusts the luminance (light amount) of the backlight as a condition.

A photosensor unit according to the present invention is presumed to be used for detecting contents displayed on a display screen of a display device, and a plate-like member formed to fit the size of the display screen, A photosensor arranged on the shape member in accordance with the arrangement of the pixels on the display screen of the display device.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram of a display system constructed using the display abnormality detection device according to the present embodiment.

The display system, as shown in FIG.
It is configured using a display device 10 for displaying information, a detection system 20 for detecting the content displayed on the display screen of the display device 10, and a control system 30 for controlling the entire system. The display abnormality detection device includes a detection system 20 and a control system 3
It consists of 0.

The display device 10 is, as shown in FIG.
This is a liquid crystal display (LCD) that displays an image (information) on a liquid crystal panel 11 that is a display screen. The liquid crystal panel 1
1, a driver circuit 12 for driving the same, a backlight unit 13 for irradiating light from the back side of the liquid crystal panel 11,
And an inverter 14 for driving the backlight unit 13
It is provided with.

The operation of the above configuration will be described. The control system 30 is configured using, for example, a personal computer (hereinafter, abbreviated as a personal computer), and is connected to the display device 10 by, for example, a cable. The display data S1 including the brightness adjustment data is transmitted via the cable.
Is output to the display device 10. The luminance adjustment data includes data for instructing a change in contrast or brightness, and data for instructing a light amount of the backlight unit 13, that is, data for instructing a voltage when the inverter 14 drives the backlight unit 13. For example, it is image data that specifies display contents in pixel units.

Although the detailed description of the detection system 20 is omitted, for example, while the power of the display device 10 is on,
A current is supplied from the display device 10 to operate. While the current is being supplied from the display device 10, the display content of the liquid crystal panel 11 is detected at a predetermined timing as needed.

As shown in FIG. 3, the photo sensor unit 21 of the detection system 20 includes a transparent member 2 such as a glass substrate that transmits light.
1a, a transparent electrode to which the terminal 21c is connected and a transparent electrode to which the terminal 21d is connected are formed in a grid,
A photosensor (phototransistor) 21b is arranged near the intersection of the transparent electrodes. The arrangement of the photo sensor 21b is performed in accordance with the arrangement of the pixels on the liquid crystal panel 11 (see FIG. 5). For this reason, the display content can be detected for each pixel. One of the two terminals of the photo sensor 21b is a terminal 21c.
Is connected to the transparent electrode to which the terminal 21 is connected.
d is connected to the connected transparent electrode. The photo sensor unit 21 can be manufactured by using, for example, the TFT technology. As a matter of course, a photodiode may be used as the photosensor 21b instead of the phototransistor.

In this manner, a large number of photo sensors 21b
The photo sensor unit 21 in which is disposed is opposed to the liquid crystal panel 11 as shown in FIG. At this time, as shown in FIG. 5, the position of the photo sensor unit 21 is adjusted such that each photo sensor 21b faces the corresponding pixel electrode (transparent electrode) 11a of the liquid crystal panel 11. Thus, the display content can be accurately detected for each pixel. Since the light emitted from the backlight unit 13 is radiated to the outside through the liquid crystal panel 11, the light amount of the backlight unit 13 itself can be directly detected. Since the photo sensor unit 21 is transparent, a decrease in visibility can be avoided even if the photo sensor unit 21 is attached to the front surface of the liquid crystal panel 11.

When the liquid crystal panel 11 is for color display, three pixels are generally allocated to each pixel. When each pixel can be decomposed into smaller elements, a photo sensor 21b may be provided for each element to detect display content in pixel units. Hereinafter, description will be made on the assumption that one pixel electrode 11a is assigned to one pixel for convenience.

The terminal 21c of the photo sensor unit 21 is connected to the scan circuit 22, and the other terminal 21d is connected to the detection circuit 2
3 is connected. The scan circuit 22 scans (scans) each terminal 21c according to the timing signal S2 output from the detection circuit 23. As a result of the scanning, a current flows through each terminal 21d from the photosensor 21b connected to the terminal 21c being scanned among the photosensors 21b to which it is connected. The current is a signal indicating the display content (here, luminance) of the facing pixel. As a result, the liquid crystal panel 11
Is extracted as an electric signal for each pixel. By dividing the display content into pixel units, the subsequent processing can be performed more easily and easily.

The detection circuit 23 converts the signal of the photo sensor 21b taken out in this way into data S3 of the same type as the display data S1 (hereinafter referred to as detection data) and outputs it to the comparison circuit 24. On the other hand, the signal of the photo sensor 21b is converted into a digital signal and output to the control system 30 as luminance data S4.

The comparison circuit 24 controls the entire detection system 20, compares the detection data S3 input from the detection circuit 23 between adjacent pixels, and controls the comparison result as detection / comparison data S5. Output to the system 30. The comparison is performed, for example, when the control system 30 monitors the content of the display data S1 output to the display device 10 and the display data S1 having a predetermined content is sent to the display device 10. More specifically, this is performed, for example, when the data indicating the display content of each pixel matches. Thereby, the comparison circuit 24 outputs a signal indicating the presence / absence of a pixel displayed in a state different from the others when all the pixels on the liquid crystal panel 11 are driven (displayed) under the same conditions as detection / comparison data S5. . Comparison circuit 2
4 controls the detection circuit 23 to cause the scan circuit 22 to scan the photo sensor unit 21.

The control system 30 outputs display data (hereinafter referred to as display abnormality detection data for convenience) S1 for driving each pixel under the same condition at a predetermined timing. The timing is, for example, when the power of the display device 10 is turned on, or when the user instructs to output the data (instructs to detect a display abnormality).

The necessity of displaying information immediately after the power of the display device 10 is turned on is relatively small. Display abnormality is found when the power is turned on,
It tends to occur at that time. For these reasons, in the present embodiment, display abnormality is detected when the power of the display device 10 is turned on. For this purpose, for example, when the power of the display device 10 is turned on, the comparison circuit 24 outputs a signal indicating this to the control system 30 in the form of the detection / comparison data S5. Control system 3
0 recognizes that the power of the display device 10 is turned on from the signal and outputs the display abnormality detection data S1.

After the display abnormality detection data S1 is output, the luminance data S4 is output from the detection circuit 23 to the comparison circuit 24.
Waits for the input of the detection / comparison data S5, and analyzes the data to determine the presence or absence of a display abnormality and its contents. The analysis is performed according to the content of the display abnormality detection data S1 output to the display device 10. Thus, based on the luminance data S4, whether the light amount of the backlight unit 13 is appropriate, in which direction the light amount needs to be adjusted if not, and whether the brightness or contrast is appropriate, If one of them is not appropriate, it is determined in which direction and how much adjustment is required. From the other detection / comparison data S5,
It is determined whether all the pixels can be driven normally or not, and if there is a pixel that cannot be driven normally, what is its ratio.

The determination based on the luminance data S4 can be performed, for example, by using the display abnormality detection data to be output to the display device 10 for each type of display abnormality (such as poor adjustment of the amount of light, brightness, and contrast of the backlight unit 13). In addition to setting S1, a table showing a range of an appropriate value and a relationship of an adjustment amount according to a difference (deviation) between the value and an actual value of the luminance data S4 is set (prepared). Do with. The control system 30 determines that a display abnormality has occurred when the value of the luminance data S4 input from the detection circuit 23 does not fall within a proper value range. The luminance data S4 is output for each pixel. For this reason, even if there is a pixel in which the value of the luminance data S4 does not fall within the proper value range, it is determined that no display abnormality has occurred if the number is within a predetermined allowable range.

As described above, the other detection / comparison data S5 is data indicating whether or not the display contents of adjacent pixels (in the vertical direction in this case) match within an allowable range. For this reason, if the number of pixels in the column (the pixels arranged in the vertical direction) is N, it is composed of (N-1) data.

A change in each data value indicates a boundary between pixels having different display contents. For this reason, the control system 30 focuses on the change in the data value, for example, roughly classifies display contents into two types, and counts the number of pixels corresponding to each display content. Normal display contents among the two types of display contents are specified with reference to the luminance data S4. Thereby,
From the detection / comparison data S5, the ratio of pixels that cannot be driven normally to the entire pixels of one column is calculated.

The above ratio is calculated not only for each column but also for the entire liquid crystal panel 11. The permissible range of the ratio of the malfunctioning pixels in each column and in the whole is set in advance. Thus, if one of the calculated ratios does not fall within the allowable range, the control system 30 determines that a display abnormality has occurred.

The light amount, brightness and contrast of the backlight unit 13 can be adjusted. For this reason, the control system 30 determines whether the display abnormality (the part to be displayed as black is bright, the part to be displayed brightly is dark, or the brightness is entirely Display error such as missing)
The brightness adjustment data generated based on the brightness data S4 is added to the display abnormality detection data S1 and output to the display device 10. Thereby, adjustment according to the display abnormality is performed, and it is confirmed whether the display abnormality has been eliminated by the adjustment. The adjustment and confirmation are repeated until the display abnormality is eliminated or it is found that the display abnormality cannot be eliminated by changing the luminance adjustment data.

The brightness adjustment data related to the adjustment of brightness and contrast is input to the driver circuit 12 of the display device 10, and the brightness adjustment data related to the adjustment of the light amount (brightness) of the backlight unit 13 is input to the inverter 14. You. The driver circuit 12 drives the liquid crystal panel 11 according to the brightness or contrast specified by the input data. Similarly, the other inverter 14 drives the backlight unit 13 with the light amount specified by the input data. Thereby, the brightness and contrast, or the light amount of the backlight unit 13 is changed.

By repeatedly performing the adjustment and confirmation as described above, the user only needs to deal with display abnormalities that the user must deal with. For this reason, not only high convenience is obtained, but also display abnormalities that need not be dealt with by the user are quickly and automatically eliminated.

When it is determined that the display abnormality cannot be eliminated by changing the brightness adjustment data, the control system 30 notifies the user of the fact. The notification is performed by, for example, displaying on the display screen of a display device (not shown) configuring the control system 30 that a display abnormality to be handled by the user himself has occurred and the content of the display abnormality. In this way, the support for instructing a response method to be taken by the user is also provided.

Display abnormalities due to defective driving of pixels are usually
It is caused by some hardware malfunction. The user must deal with hardware malfunctions. For this reason, when such a display abnormality occurs, it is indicated on the display screen of the display device constituting the control system 30 that a display abnormality to be dealt with by the user has occurred.
The contents of the display abnormality (a large number of malfunctioning pixels) are immediately displayed.

The above-mentioned notification of the display abnormality is automatically made by the control system 30 judging the occurrence of the display abnormality from the contents displayed on the liquid crystal panel 11 of the display device 10. Therefore, the user can know the occurrence of the display abnormality without actually looking at the liquid crystal panel 11 (display screen) of the display device 10. This means that the user can quickly and promptly know the occurrence of the display abnormality regardless of the installation location of the display device 10. For this reason, display abnormalities can be promptly dealt with, and problems caused by display abnormalities that information to be transmitted cannot be appropriately transmitted to a target person can be minimized.

In the present embodiment, the detection system 20 and the control system 30 constitute a display abnormality detecting device. However, at least a part of the display abnormality detecting device must be attached to the display device 10. Therefore, the display abnormality detection device may be mounted on the display device 10. In such a case, the photo sensor unit 21 may be incorporated in the liquid crystal panel 11. Specifically, for example, as shown in FIG. 6, a photo sensor 21b may be provided outside a transparent member (for example, a glass substrate) constituting the liquid crystal panel 11. Or, FIG.
As shown in the figure, a photo sensor 21 is provided inside the transparent member.
b may be provided. Photo sensor unit 2 on liquid crystal panel 11
When 1 is incorporated, there are advantages in manufacturing such that the number of components is reduced, and the labor for attaching the photo sensor unit 21 to the liquid crystal panel 11 is eliminated.

The photo sensor section 21 has a photo sensor 21b for detecting the display content for each pixel, but the photo sensor 21b may not be provided for each pixel. One photosensor 21b may be provided only in accordance with the arrangement of the pixels. Photo sensor 21 to be provided
As b decreases, the detection accuracy of the display abnormality decreases.
The decrease in accuracy has the greatest effect on the detection of display abnormalities due to defective operation of pixels. From this, the photo sensor 21b
If not provided for each pixel, the number (including the arrangement)
Is desirably determined by focusing on a decrease in visibility caused by a malfunction of the pixel. If the number of defective pixels is excluded from the detection target, the number of the pixels can be reduced while suppressing a decrease in detection accuracy. In order to detect the display content, a device other than the photo sensor unit 21 such as a CCD image sensor may be used.

Although the display device 10 is a liquid crystal display device, the detection target of a display abnormality is not limited to the liquid crystal display device. The display device 10 may be another type of display device such as an LED display, PDP, FED, VFD, and EL display. Since those display devices are of a self-luminous type, as shown in FIG.
Display panel 81 and driver circuit 82 for driving it
This is a configuration including:

At present, it is also common practice to modularize a liquid crystal display device or the like and form a larger display screen by combining a plurality of such devices. In such a case, if driving conditions such as brightness and contrast are different for each display device, a display abnormality occurs in which information becomes difficult to recognize.

However, such display abnormalities are caused, for example, by the photo sensor unit 21, the scan circuit 22,
And a detection circuit 23, each detection circuit 23 is connected to one comparison circuit 24, and the comparison circuit 24 has a function of comparing display contents (detection data S3) of corresponding pixels between adjacent display devices. Control system 30
In addition, the detection can be performed by providing a function of judging a display abnormality from a result of comparison of display contents between the display devices, which is output as the detection / comparison data S5 by the comparison circuit 24. These functions can be realized by the same method as when only one display device is targeted. For this reason, a display abnormality detection device that detects a display abnormality for a plurality of display devices can be basically realized by increasing the number of components illustrated in FIG. The same applies to a case where a function for changing the driving conditions of each display device is further mounted. However, as a matter of course, the configuration of the display abnormality detection device is not limited thereto.

In this embodiment, in order to detect a display abnormality, the comparison circuit 24 compares the display state (detection data S3) between adjacent pixels. Instead of performing such a comparison, the comparison circuit 24 displays the display data S
Since 1 is input, for example, the detection data S3 and the display data S1 may be associated and compared. You may confirm whether the information which instruct | indicated the display to the display apparatus 10 and the information which it actually displayed corresponded within the permissible range. In such a case, a display abnormality can be detected in pixel units regardless of the content of the display data S1. While displaying information to be displayed, a display abnormality can be detected in a pixel unit at any time. Therefore, higher convenience can be obtained. As for the detection of the display abnormality, the display abnormality may be detected in the pixel unit by sequentially changing the pixel for displaying the information in the pixel unit. As is apparent from the above, various methods can be used for detecting the display abnormality, or they can be combined.

In a liquid crystal display device that is not a self-luminous type, display abnormalities occur not only due to brightness and contrast but also due to the amount of light from the backlight. In the present embodiment, the light amount is directly detected. However, for example, as shown in FIG. 9, the photo sensor 91 is provided on the back side of the backlight unit 13 (the side opposite to the side on which the liquid crystal panel 11 is installed). May be provided to detect light leaking to the back side of the backlight unit 13. The photo sensor 91 is connected to the photo sensor unit 21
And may be provided together.

In the present embodiment, a display abnormality is dealt with by adjusting driving conditions such as brightness and contrast, or the amount of light of the backlight unit 13. However, in the display device, the display content may change depending on the position on the display panel. For example, in a liquid crystal display device, the amount of light emitted from a backlight unit to a liquid crystal panel often differs slightly depending on the position. In an LED display, the brightness when the same voltage is applied may slightly change for each LED due to a difference in deterioration over time.
These cannot be eliminated by adjusting the driving conditions.

For this reason, the display data itself may be manipulated so that the display content does not change depending on the position of the display panel. In such a case, information to be displayed can be displayed in a more preferable state regardless of the number of display devices to be detected as display abnormalities.

The display abnormality detecting device according to the present invention may be realized simply as a device for detecting a display abnormality. As an application, it may be used not for detecting a display abnormality occurring in a display device in use but for confirming whether or not a manufactured display device operates normally. When the use is limited, it is desirable that the display device can be easily attached to and detached from the display device.

[0046]

As described above, according to the present invention, the display content of the display screen being driven by the display device is detected, and a display abnormality occurring on the display screen is detected based on the detection result. In this way, the display abnormality is automatically detected, so that the user can quickly and promptly know the occurrence of the display abnormality regardless of the installation location of the display device.

Further, according to the present invention, when a display abnormality is detected, the condition for driving the display screen of the display device is adjusted according to the content of the display abnormality. Therefore, the number of cases that need to be dealt with by the user is reduced and the burden is reduced, and display abnormalities that need not be dealt with by the user can be quickly eliminated.

When a photo sensor unit in which at least one photo sensor is arranged on a plate-like member in accordance with the arrangement of pixels on a display screen of a display device is used for detecting display content, the display content is displayed in pixel units. It can be converted to an electrical signal. For this reason, display abnormalities can be detected by simpler processing.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a display system constructed using a display abnormality detection device according to the present embodiment.

FIG. 2 is a diagram illustrating a circuit configuration of a display device.

FIG. 3 is a diagram illustrating a structure of a photo sensor unit.

FIG. 4 is a diagram illustrating the installation location of a photo sensor unit.

FIG. 5 is a diagram illustrating display contents detected by a photo sensor unit.

FIG. 6 is a view for explaining another method of forming the photosensor portion (part 1).

FIG. 7 is a view for explaining another method of forming the photosensor portion (part 2).

FIG. 8 is a diagram illustrating a circuit configuration of another display device.

FIG. 9 is a diagram illustrating another method of detecting display content.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Display apparatus 11 Liquid crystal panel 11a Pixel electrode 12, 82 Driver circuit 13 Backlight part 14 Inverter 20 Detection system 21 Photosensor part 21a Transparent member 21b, 91 Photosensor 21c, 21d Terminal 22 Scan circuit 23 Detection circuit 24 Comparison circuit 30 Control System 81 Display panel

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Tetsuya Takanashi 1776 Yanoguchi, Inagi-shi, Tokyo Inside Fujitsu Kiden Co., Ltd. Person Hidenobu Hamada 1776 Yanoguchi, Inagi-shi, Tokyo Inside Fujitsu Machine Electric Co., Ltd. TA07 TA09 TA18 5G435 AA00 BB12 BB15 EE25 EE30 EE33 GG21 GG22 HH02

Claims (6)

[Claims] 1. An apparatus for detecting a display abnormality in displaying information generated on a display screen of a display device, wherein the display device detects display contents of a display screen being driven by the display device. And a display abnormality detecting means for detecting a display abnormality occurring on the display screen based on a detection result of the display content detecting means. And a driving condition adjusting means for adjusting a condition for driving the display screen according to the content of the display abnormality when the display abnormality detecting means detects the display abnormality. The display abnormality detection device according to claim 1, wherein: 3. The display content detection unit detects the display content in units of pixels on the display screen, and the display abnormality detection unit detects the display abnormality in units of pixels. The display abnormality detection device according to claim 1 or 2, wherein 4. The display abnormality detecting means, wherein when the display device is a liquid crystal display device, the display content detecting means detects a light amount of a backlight mounted on the liquid crystal display device as the display content. The display abnormality detection device according to claim 1, wherein the display abnormality is detected based on a light amount of a backlight detected by the display content detection unit. 5. The display abnormality detecting device according to claim 4, wherein the driving condition adjusting means adjusts the brightness of the backlight as the condition. 6. A unit for detecting contents displayed on a display screen of a display device, comprising: a plate-shaped member formed in accordance with the size of the display screen; A photosensor unit comprising: a photosensor arranged in accordance with an arrangement of pixels on a display screen of a display device.