JP2012022040A - Image display device and manufacturing method of image display device - Google Patents

Abstract

An abnormality of a lower bit can be detected by arranging gradation patterns of mixed colors.
An image display device 10 includes a color TFT liquid crystal display 11. When the inspection mode is selected, the image display device 10 displays the test pattern 11a on the display unit 11. The test pattern 11a has a plurality of gradation patterns 11c, 11m, and 11y. Each of these gradation patterns displays a different mixed color. The plurality of gradation patterns are displayed side by side so that they can be compared with each other. If there is an abnormality in the data specifying the gradation of any one basic color, the gradation pattern of the mixed color including the basic color changes. On the other hand, the gradation pattern of the mixed color not including the basic color displays a normal gradation pattern. For this reason, an abnormal state can be displayed in an easy-to-understand manner.
[Selection] Figure 3

Description

  The present invention relates to an image display device and a method for manufacturing the image display device.

  Conventionally, an image display device that displays a predetermined test pattern is known. There is also known a method for manufacturing an image display device including an inspection process for determining whether the image display device is normal or abnormal by displaying a predetermined test pattern on the image display device. For example, the image display devices of Patent Document 1 and Patent Document 2 display a gradation pattern in which the gradation of a specific color is gradually changed, that is, a gradation.

  Patent Document 3 discloses a gradation pattern based on received digital data and a gradation pattern based on inverted digital data in order to detect the loss of the least significant bit of digital data supplied as a video signal. Propose to provide. According to this configuration, even if the least significant bit is missing, a large difference in gradation is displayed. For this reason, it is possible to reliably inspect the lack of the least significant bit.

  Further, the image display device of Patent Document 4 divides digital data into an upper bit group and a lower bit group, and displays a gradation pattern by an upper bit group and a gradation pattern by a lower bit group side by side on a screen. Has proposed.

JP 2008-177704 A JP 2010-87793 A JP 2006-243420 A JP 2007-322533 A

  In the above prior art, it is still difficult to identify the difference between the gradation pattern at the normal time and the gradation pattern at the abnormal time. Such difficulty in identification is the same whether a person inspects or an inspection apparatus.

  Also, if there is an abnormality in the digital data of one color and there is no abnormality in the digital data of the other colors, when they are mixed and displayed, the normal gradation pattern and the abnormal gradation pattern It was difficult to identify the difference. For example, when RGB is mixed and a gradation between white and black is displayed as a gradation pattern, it is difficult to detect a missing bit of any one of RGB from the gradation pattern.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to make it possible to detect, by displaying a gradation pattern, that there is an abnormality in some bits of digital data specifying a gradation of color. An object of the present invention is to provide an image display device and a method of manufacturing an image display device using the image display device.

  Another object of the present invention is to provide an image display device that can detect an abnormality of lower bits of digital data in the image display device by displaying a gradation pattern, and a method of manufacturing an image display device using the image display device. is there.

  Another object of the present invention is to provide an image display device capable of detecting an abnormality in a lower bit of any one of a plurality of digital data corresponding to a plurality of colors by displaying a gradation pattern, and the image display device An object of the present invention is to provide a method for manufacturing the image display device used.

  The present invention employs the following technical means to achieve the above object.

  The invention described in claim 1 includes a color display (11), a display control device (13, 14, 15, 16) for displaying an image on the display (11), a display and a display control device (13). 14, 14, 15, 16) and a display control device (13, 14, 15, 16) on the display (11) with a plurality of different mixed colors. It is characterized by comprising display means (132) for displaying gradation patterns in a state where they can be compared with each other.

  According to the present invention, it is possible to display that there is an abnormality such as a disconnection in a connection line by a difference between a plurality of gradation patterns. Moreover, a clear and easy-to-see display can be provided by adopting the mixed color.

  The invention according to claim 2 is characterized in that the display means (132) displays a plurality of gradation patterns side by side. According to the present invention, the difference between the plurality of gradation patterns can be easily detected by comparing the plurality of gradation patterns.

  According to a third aspect of the present invention, the display means (132) is configured to output digital data indicating each gradation of a plurality of basic colors, and each of the plurality of mixed colors includes at least two basic colors. It is characterized by including a color. According to the present invention, a mixed color is expressed by changing the gradation of at least two basic colors. For this reason, it is possible to identify the basic color in which an abnormality has occurred from the difference between a plurality of gradation patterns.

  According to a fourth aspect of the present invention, the plurality of mixed colors include cyan, magenta, and yellow. According to the present invention, an apparatus effective for an RGB system can be provided.

  The invention according to claim 5 is characterized in that the display means (132) displays the gradation pattern with the highest resolution that can be provided by the digital data indicating the gradation. According to the present invention, it is possible to detect an abnormality including a missing minimum bit.

  The invention according to claim 6 connects the color display (11) and the display control device (13, 14, 15, 16) for displaying an image on the display (11) by the connection line (18), The display control device (13, 14, 15, 16) displays a plurality of gradation patterns with different mixed colors on the display (11) in a state where they can be compared with each other. The connection line (18) is determined to be normal or abnormal based on the presence or absence of a difference.

  According to the present invention, it is possible to display that there is an abnormality such as a disconnection in a connection line by a difference between a plurality of gradation patterns. Moreover, a clear and easy-to-see display can be provided by adopting the mixed color. As a result, good products can be selected in the manufacturing process of the image display device.

  The invention according to claim 7 is characterized in that a plurality of gradation patterns are displayed side by side. According to the present invention, the difference between the plurality of gradation patterns can be easily detected by comparing the plurality of gradation patterns.

  In the invention according to claim 8, the gradation pattern is configured by digital data indicating the gradation of each of the plurality of basic colors, and each of the plurality of mixed colors includes at least two basic colors. Features. According to the present invention, a mixed color is expressed by changing the gradation of at least two basic colors. For this reason, it is possible to identify the basic color in which an abnormality has occurred from the difference between a plurality of gradation patterns.

  The invention according to claim 9 is characterized in that the plurality of mixed colors include cyan, magenta, and yellow. According to the present invention, an apparatus effective for an RGB system can be provided.

  The invention according to claim 10 is characterized in that the gradation pattern is displayed with the highest resolution that can be provided by digital data indicating gradation. According to the present invention, it is possible to detect an abnormality including a missing minimum bit.

  Note that the reference numerals in parentheses described in the claims and the above-described means indicate the correspondence with the specific means described in the embodiments described later as one aspect, and are technical terms of the present invention. It does not limit the range.

It is a block diagram which shows the display apparatus for vehicles which concerns on 1st Embodiment to which this invention is applied. It is a state transition diagram which shows the transition of the operating state of the display apparatus for vehicles of 1st Embodiment. It is a top view which shows the test pattern which concerns on 1st Embodiment. It is a top view which shows the gradation at the time of the normal of the test pattern which concerns on 1st Embodiment. It is a top view which shows the gradation at the time of abnormality of the test pattern which concerns on 1st Embodiment.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. Not only combinations of parts that clearly show that combinations are possible in each embodiment, but also combinations of the embodiments even if they are not explicitly stated unless there is a problem with the combination. Is also possible.

(First embodiment)
FIG. 1 is a block diagram showing a vehicle display device according to a first embodiment to which the present invention is applied. The vehicle image display device 10 constitutes a part of the in-vehicle information system 1. The in-vehicle information system 1 is mounted on a vehicle and displays a still image and a moving image.

  The vehicle information system 1 includes an in-vehicle video device 20 and an external camera 30 as sources of still images and moving images. The in-vehicle video equipment 20 can include a recording medium playback device such as a DVD playback device, an in-vehicle information device such as a navigation device, and a broadcast reception device that receives a television broadcast. A first image signal is output from the in-vehicle video device 20. The first image signal can also be referred to as a first video signal. The external camera 30 captures a landscape such as a road around the vehicle and outputs a second image signal.

  The in-vehicle information system 1 includes a switch device 40 for inputting a command signal (command) for switching images. The switch device 40 includes, for example, a power switch. In addition, a switch for shifting from a display mode as a normal function to a maintenance mode such as an inspection mode or an adjustment mode can be provided. Further, the switch device 40 includes a switch for instructing the progress to the next process in the inspection mode or the adjustment mode, and a switch for instructing to end the inspection mode or the adjustment mode and return to the display mode. Can do.

  The image display device 10 includes a color display 11 and a backlight type illumination device 12 for the display 11. The display 11 is a color TFT liquid crystal display and displays a color image according to an input signal. The illumination device 12 supplies illumination light from the back surface of the display 11.

  The image display device 10 includes a display control circuit 13, a ROM 14, a VRAM 15, an LVDS encoder 16, and a CPU 17. The ROM 14 is a nonvolatile memory provided as a recording medium. The ROM 14 provides storage means for storing a test pattern to be described later. The VRAM 15 is an image read / write memory provided as a recording medium. An LVDS (Low Voltage Differential Signaling) encoder 16 is a conversion circuit that converts an image signal supplied from the display control circuit 13. The CPU 17 is an arithmetic processing device provided as a control device, and controls the components of the image display device 10. The CPU 17 is connected to the switch device 40. The CPU 17 inputs a command signal from the switch device 40. Further, the CPU 17 is connected to the lighting device 12. The CPU 17 turns on or turns off the lighting device 12 in accordance with a command signal input from the switch device 40.

  The display control circuit 13, the ROM 14, the VRAM 15, the LVDS encoder 16, and the CPU 17 constitute a display control device. This display control device is connected to the display 11 by a connection line 18. The connection line 18 connects between the LVDS encoder 16 and the display 11. The connection line 18 transmits digital data indicating each gradation of a plurality of basic colors.

  The connection line 18 includes a DOT_CLK line that transmits a clock signal as a synchronization signal, and a digital signal line group for transmitting digital data that specifies gradations of a plurality of RGB colors. The digital signal line group includes a D_R line group indicating a red gradation, a D_G line group indicating a green gradation, and a D_B line group indicating a blue gradation. Each of the D_R line group, the D_G line group, and the D_B line group is an 8-bit parallel line. Of the 8 bits, 6 bits are used for gradation command. Therefore, there are 64 gradation levels. A parallel line having connectors at both ends is used for at least a part of the connection line 18. For example, a flexible printed board called FPC is used for the parallel lines. For this reason, there exists a possibility of producing the disconnection resulting from a contact failure in a connector.

  FIG. 2 is a state transition diagram showing the transition of the operation state of the image display device 10. The image display device 10 includes a stop mode 100 for stopping the display device 11 and an operation mode 110 for activating the display device 11. In the stop mode 100, nothing is displayed on the display 11. In the operation mode 110, an image is displayed on the display 11. The operation mode 110 includes a display mode 120, an inspection mode 130, and an adjustment mode 140. The inspection mode 130 is a display mode for determining whether or not the display function of the image display apparatus 10 is normally performed. The inspection mode 130 is configured to be activated when shipped from the factory. Software and image data for executing the inspection mode 130 can be stored in the ROM 14. The inspection mode 130 can be configured to be activated only when the image display apparatus 10 is shipped from the factory. Furthermore, the image display device 10 may be configured to read and execute software and image data for executing the inspection mode 130 into the image display device 10 only at the time of factory shipment.

  The display mode 120 includes a first image mode 121 and a second image mode 122. In the first image mode 121, an image based on the first image signal from the vehicle-mounted video device 20 is displayed on the display 11. In the second image mode 122, an image based on the second image signal from the external camera 30 is displayed on the display 11.

  In the inspection mode 130, a predetermined test pattern is displayed on the display 11. First, in the first inspection screen mode 131, a test pattern called a white screen that makes the entire surface of the display device 11 white is displayed on the display device 11. In the first examination screen mode 131, non-lighting of the display unit is detected. Next, in the second inspection screen mode 132, a test pattern called a multi-mixed color gradation pattern is displayed on the display 11. In the second inspection screen mode 132, by displaying a plurality of gradation patterns (gradations) with different mixed colors, it is determined whether the change in hue and the change in luminance satisfy a predetermined standard. Furthermore, the abnormality of the digital data designating the gradation is inspected by the change in gradation appearing in the gradation pattern. The second examination screen mode 132 is provided by hardware and / or software provided in the image display device 10. The second inspection screen mode 132 provides a display means for displaying a plurality of gradation patterns. In the third inspection screen mode 133, a test pattern called a black screen that makes the entire surface of the display 11 black is displayed on the display 11. In the third inspection screen mode 133, a bright spot of a display unit is detected.

  The inspection mode 130 is executed in a part of the manufacturing process of the image display device 10. The inspection mode 130 is executed after the display device 11 and the display control device are connected by the connection line 18. In particular, in the second inspection screen mode 132, the display control apparatus displays a plurality of gradation patterns of a plurality of mixed colors on the display 11 in a state where they can be compared with each other. Accordingly, an inspector who is involved in the manufacturing method of the image display device or an inspection device used in the manufacturing method determines whether the connection line 18 is normal or abnormal based on the presence or absence of a plurality of gradation patterns. For example, if there is no difference in gradation pattern, it can be determined that the image display apparatus 10 is normal, and if there is a difference in gradation pattern, it is determined that the image display apparatus 10 is abnormal.

  In the adjustment mode 140, an image such as a predetermined test pattern is displayed on the display unit 11. First, in the color adjustment mode 141, an image suitable for adjusting the display color of the display 11 is displayed. In the color adjustment mode 141, the switch device 40 is operated so as to adjust the display color, and the adjustment amount is set in the display control circuit 13. Next, in the brightness adjustment mode 142, an image suitable for adjusting the brightness of the display 11 is displayed. In the brightness adjustment mode 142, the switch device 40 is operated so as to adjust the brightness, and the adjustment amount is set in the display control circuit 13.

  Switching between a plurality of modes shown in the figure is executed in response to a command signal input by operating a switch means included in the switch device 40. The command signal includes “power ON”, “power OFF”, “switch”, “inspection”, “adjustment”, “next process”, “end”, and the like. “Power ON” is input by operating the power switch to the ON state. “Power OFF” is input by operating the power switch to the OFF state. “Switching” is input by operating the selector switch. “Inspection” is input by operating a switch for instructing the transition to the inspection mode 130. Since the inspection mode 130 is a mode executed at the time of factory shipment, the input of “inspection” can be configured to be input by a combination operation of a plurality of switches or an operation that can be performed only at the time of factory shipment. . “Adjustment” is input by operating a switch for instructing transition to the adjustment mode 140. The “next process” is input by operating a switch for instructing the transition to the next process. “End” is input by operating a switch for instructing the return from the inspection mode 130 or the adjustment mode 140 to the display mode 120.

  FIG. 3 is a plan view showing the test pattern 11 a displayed in the second inspection screen mode 132. Coordinate information indicating the display position of the test pattern, color information indicating the display color, and gradation information indicating the gradation are recorded in the ROM 14.

  The test pattern 11a is displayed in a predetermined area of the display 11. The test pattern 11a is composed of a plurality of gradation patterns. The gradation pattern can also be called gradation. The test pattern 11a includes a C (cyan) gradation pattern 11c, an M (magenta) gradation pattern 11m, and a Y (yellow) gradation pattern 11y.

  The plurality of gradation patterns are displayed with different mixed colors. The mixed color is a color obtained by mixing at least two of a plurality of basic colors. Therefore, the mixed color includes at least two basic colors as components. In this embodiment, three colors of R (red), G (green), and B (blue) are used as basic colors. Therefore, three mixed colors of C (cyan), M (magenta), and Y (yellow) are produced.

  The basic color is expressed by digital data indicating gradation. The basic color is given 64 gradations from 0 to 63 by 6-bit information.

  The mixed color is composed of two basic colors having the same gradation. For example, the mixed color M is composed of a basic color R and a basic color B having the same gradation. Further, the gradation pattern of the mixed color M is expressed by changing only the gradation of the basic color R and the basic color B. That is, one gradation pattern is expressed by changing only the gradation of the basic color included as a component in the mixed color.

  Digital data for displaying one gradation pattern is given so as to display from the maximum value to the minimum value of the gradation with the highest resolution. One gradation pattern represents a gradation from the mixed color to the background color of the display 11. For example, the M gradation pattern 11m represents a gradation from magenta to black. One gradation pattern is composed of 64 squares. Each square displays a different gradation. For example, in the M gradation pattern 11m, the basic color gradation is “R: 0, G: from the grid 11m-63 whose basic color gradation is“ R: 63, G: 0, B: 63 ”. “0, B: 0” squares 11m-0 are arranged in order. That is, the test pattern 11a is set to display a gradation pattern with the highest resolution that can be provided by digital data indicating gradation.

  The plurality of gradation patterns are arranged side by side so that they can be compared with each other. The plurality of gradation patterns are arranged adjacent to each other. The plurality of gradation patterns are arranged in a state where two mixed colors including at least one common basic color are close enough to be compared with each other. Regarding R, two mixed colors M and C including R are arranged adjacent to each other. Regarding G, two mixed colors C and Y including G are arranged adjacent to each other. Regarding B, two mixed colors including B, Y and M, are separated, but are arranged at close positions that are still comparable. In the illustrated example, an M gradation pattern 11m, a C gradation pattern 11c, and a Y gradation pattern 11y are arranged.

  The plurality of gradation patterns are arranged so that the change directions of the gradations coincide with each other. The plurality of gradation patterns are arranged so that the increasing directions of the gradations coincide with each other. The plurality of gradation patterns are arranged so that the increasing directions of the gradations are parallel to each other. The plurality of gradation patterns are arranged such that their starting points are aligned on the same line and their end points are aligned on the same line. A plurality of gradation patterns are displayed so as to increase or decrease by the same unit gradation for each same width. Each of the plurality of gradation patterns is displayed by gradually increasing or decreasing the gradation from the start point to the end point. The change in gradation is visually recognized as a change in luminance of the mixed color on the display 11.

  As described above, the connection line 18 may cause a contact failure in the connector. This poor contact results in the loss of certain bits. In this case, the image display apparatus 10 cannot display an image normally. Even when the above-described test pattern 11a is displayed, the test pattern 11a is not accurately reproduced. When the missing bit is the lower bit, the difference in gradation is small. For example, when the gradation is 64 levels, the least significant bit only gives a minute difference of 1/64 of the gradation. The lower second bit only gives a minute difference of 1/32 of the gradation. Such a minute difference in gradation appears in a minute luminance difference on the display 11. It is not easy to identify such a small difference in brightness by the examiner's naked eyes or by an image recognition device of an automatic inspection device. However, in this embodiment, the test pattern 11a is improved. For this reason, the abnormality of the lower bits is displayed in an easy-to-understand manner.

  FIG. 4 is a plan view showing a gradation in a normal state. When normal, all gradation patterns 11m, 11c, and 11y are displayed with the maximum resolution. At this time, the gradation patterns 11m, 11c, and 11y show a smooth color change. In addition, the luminance changes of all the gradation patterns 11m, 11c, and 11y are as smooth as each other. For example, there is no significant difference in luminance change between the gradation pattern 11m and the gradation pattern 11c. In addition, there is no significant difference in luminance change between the gradation pattern 11c and the gradation pattern 11y. In addition, there is no significant difference in luminance change between the gradation pattern 11y and the gradation pattern 11m.

  FIG. 5 is a plan view showing gradations at the time of abnormality. Here, a case is shown in which only the least significant bit of the signal line for instructing the R gradation is broken. In this case, information of 1, 3, 5... 61, 63 is missing. Therefore, R is displayed with 32 gradation levels. In this case, only R has a gradation of 32 levels, and G and B have a gradation of 64 levels. Furthermore, M and C containing R as a component also have 32 stages. In the illustrated example, the gradation pattern 11m and the gradation pattern 11c have 32 levels, and the gradation pattern 11y has 64 levels.

  In other words, the gradation change of the two gradation patterns 11m and 11c reflects the abnormality of the least significant bit. For this reason, the gradation change resulting from the abnormality of the least significant bit is displayed over a wide area. Accordingly, gradation abnormality is easily detected.

  Further, the gradation pattern of the mixed color including the basic color causing the abnormality changes to an abnormal gradation pattern. On the other hand, the gradation pattern of the mixed color not including the basic color is a normal gradation pattern. Therefore, since two gradation patterns can be compared, abnormality is easily detected. In the illustrated example, a normal gradation pattern 11y with the highest resolution is displayed as the gradation pattern 11y. For this reason, the gradation pattern 11y functions as a reference gradation pattern. The inspector or the inspection apparatus can determine the abnormality of the two gradation patterns 11m and 11c while referring to the normal gradation pattern 11y.

  Furthermore, basic colors common to abnormal gradation patterns are known. Therefore, by determining a basic color common to two mixed colors in which an abnormality is found in the gradation change, it is possible to identify a basic color in which an abnormality has occurred, that is, a connection line in which an abnormality has occurred.

Furthermore, it is possible to provide a display that is easier for an inspector to view and can be easily photographed by an image recognition device than arranging three basic colors of RGB. For example, regarding B, it is difficult to distinguish it from black when the gradation of B decreases. On the other hand, the mixed color is a relatively bright color. For this reason, the difference in gradation change is displayed in an easy-to-view or easy-to-detect manner. Thus, according to this embodiment, a slight abnormality in gradation change can be easily displayed. For this reason, it can be detected by displaying the gradation pattern that there is an abnormality in a part of the bits of the digital data specifying the gradation of the color. Furthermore, even if an abnormality occurs in any of the lower-order bits of the digital data, the abnormality can be detected. Furthermore, it is possible to specify whether an abnormality has occurred in any of the plurality of colors.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. The structure of the said embodiment is an illustration to the last, Comprising: The scope of the present invention is not limited to the range of these description. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  For example, 256 levels of gradation may be displayed using all 8 bits for gradation commands. For example, the present invention may be applied to a system that uses six colors of RGBCMY as basic colors. In this case, more than three mixed colors can be used. Further, the plurality of gradation patterns may be arranged so that the gradation changes in the vertical direction. The plurality of gradation patterns may be arranged radially or concentrically. The display 11 is not limited to a liquid crystal display, and a display device capable of color gradation display can be used. For example, a CRT display or a plasma display can be used.

  DESCRIPTION OF SYMBOLS 1 In-vehicle information system, 10 Image display apparatus, 20 In-vehicle image equipment, 30 External camera, 40 Switch apparatus, 11 Display

Claims (10)

A color indicator (11);
A display control device (13, 14, 15, 16) for displaying an image on the display (11);
A connection line (18) for connecting the display and the display control device (13, 14, 15, 16);
The display control device (13, 14, 15, 16) displays, on the display (11), a plurality of gradation patterns with different mixed colors in a state where they can be compared with each other. An image display device comprising:   The image display device according to claim 1, wherein the display means (132) displays the plurality of gradation patterns side by side.   The display means (132) is configured to output digital data indicating each gradation of a plurality of basic colors, and each of the plurality of mixed colors includes at least two basic colors. The image display device according to claim 1 or 2.   The image display apparatus according to claim 3, wherein the plurality of mixed colors include cyan, magenta, and yellow.   5. The image display device according to claim 1, wherein the display means (132) displays the gradation pattern with the highest resolution that can be provided by digital data indicating gradation. A color display (11) and a display control device (13, 14, 15, 16) for displaying an image on the display (11) are connected by a connection line (18),
The display control device (13, 14, 15, 16) displays a plurality of gradation patterns with different mixed colors on the display (11) in a state where they can be compared with each other,
A method for manufacturing an image display device, comprising: determining whether the connection line (18) is normal or abnormal based on the presence or absence of a plurality of gradation pattern differences.   The method according to claim 6, wherein the plurality of gradation patterns are displayed side by side.   7. The gradation pattern is configured by digital data indicating gradations of a plurality of basic colors, and each of the plurality of mixed colors includes at least two of the basic colors. Or a method of manufacturing the image display device according to 7;   The method of manufacturing an image display device according to claim 8, wherein the plurality of mixed colors include cyan, magenta, and yellow.   10. The method of manufacturing an image display device according to claim 6, wherein the gradation pattern is displayed with the highest resolution that can be provided by digital data indicating gradation.

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