Non-uniformity evaluation apparatus, non-uniformity evaluation method, and display inspection apparatus and program

• US 8,368,750 B2
• Filed: 12/21/2009
• Issued: 02/05/2013
• Est. Priority Date: 12/24/2008
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Mori, Yumi, Nakano, Hiroki
• Primary Examiner(s): Ustaris, Joseph
• Assistant Examiner(s): HOLDER, ANNER N
• Application Number:
  US12/643,017
• Publication Number:
  US 20100157044A1
• Time in Patent Office: 1,142 Days
• Field of Search: 348/92, 348/58, 348/42
• US Class Current: 348/92
• CPC Class Codes: G06T 11/206 Drawing of charts or graphs
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30121 CRT, LCD or plasma display
• CPC Class Codes: G06T 7/0004 Industrial image inspection

Abstract

A mura evaluation apparatus 100 includes: a mura detection unit 110 that acquires multiple images of a display mura present in a display area of a display device by scanning the display area while moving along a spherical surface with a preset radius; and an information processing apparatus 150 that generates a three-dimensional mura figure from the multiple images acquired by the mura detection unit, by associating a feature value of the display mura in each of the images with a position where the image is acquired, and generates a mura superimposed image in which the three-dimensional mura figure viewed from a designated observation angle is superimposed.

Claims

1. A non-uniformity evaluation apparatus for evaluating a display non-uniformity (also called “

mura”

below) of a display device, comprising;

a non-uniformity detection unit that acquires a plurality of images of a display mura present in a display area of the display device by scanning the display area while moving along a spherical surface with a preset radius; and

an information processing apparatus that generates a three-dimensional mura figure from the plurality of images acquired by the non-uniformity detection unit, by associating a feature value of the display mura in each of the images with a position where the image is acquired, and displays the three-dimensional mura figure superimposed on a virtual plane representing the display area so that the three-dimensional mura figure can be viewed from a designated observation angle,

wherein the information processing apparatus further comprises;

a memory device that obtains an elevation angle and an azimuth angle as the position, and stores two kinds of three-dimensional mura figure data, one of which is three-dimensional mura figure data specified by a feature value of the display mura at each of the positions, and the other of which is three-dimensional mura figure data having coordinates converted into a Cartesian coordinate system from those in the former three-dimensional mura figure data,

a controlling device that calculates the three-dimensional mura figure viewed when the virtual plane is viewed from the observation angle, and generates a mura superimposed image in which the three-dimensional mura figure is superimposed on the virtual plane, and

a control I/O unit section that outputs the three-dimensional mura figure superimposed on the virtual plane.

2. The non-uniformity evaluation apparatus according to claim 1, wherein the non-uniformity detection unit includes:

a camera that acquires the images;

a camera driving unit that moves the camera to such positions that the images of the display mura can be captured; and

a stage driving unit that positions the display mura, targeted for the image capturing, within a field of view of the camera.

3. The non-uniformity evaluation apparatus according to claim 2, wherein

the controlling device generates the three-dimensional mura figure as a three-dimensional mura figure curved plane which smoothly connects the three-dimensional mura figure data or gives a minimal residual.

4. The non-uniformity evaluation apparatus according to claim 3, wherein

the controlling device defines a handle for rotating the virtual plane, and

the controlling device rotates the virtual plane in response to an operation preformed on the handle, recalculates the three-dimensional mura figure curved plane according to the rotation, and then updates the mura superimposed image by superimposing the recalculated three-dimensional mura figure curved plane on the virtual plane.

5. A non-uniformity evaluation method for evaluating a display mura of a display device, the non-uniformity evaluation method comprising the steps of:

capturing an image of a display area of the display device set within a field of view of a camera;

extracting display muras from the image of the display area thus captured, the display mura targeted for three-dimensional mura figure data generation;

capturing images of each of the display muras at different elevation angles and azimuth angles with respect to the camera, generating three-dimensional mura figure data by calculating a feature value of the display mura at each pair of an observation angle and the azimuth angle, and generating a three-dimensional mura figure curved plane from the three-dimensional mura figure data; and

calculating the three-dimensional mura figure curved plane viewed when the display area is viewed from the observation angle, and displaying a mura superimposed image in which the three-dimensional mura figure curved plane is superimposed on a virtual plane that represents the display area.

6. The non-uniformity evaluation method according to claim 5, wherein the step of displaying further includes the steps of:

defining a handle for rotating the virtual plane, and

rotating the virtual plane in response to an operation performed on the handle, and updating the mura superimposed image by recalculating the three-dimensional mura figure curved plane according to the rotation.

7. The non-uniformity evaluation method according to claim 6, wherein the step of displaying further includes the step of displaying a region having a feature value equal to or higher than a threshold set for the display mura, the region being superimposed, as a portion different in hue or luminance, on the three-dimensional mura figure curved plane at a position in a bottom surface of the three-dimensional mura figure.

8. The non-uniformity evaluation method according to claim 7, wherein the step of generating the three-dimensional mura figure curved plane includes the step of generating the three-dimensional mura figure as a three-dimensional mura figure curved plane which smoothly connects the three-dimensional mura figure data or gives a minimal residual.

9. A display inspection apparatus for evaluating a display mura of a display device, comprising:

a non-uniformity detection unit that acquires a plurality of images of a display mura present in a display area of the display device by scanning the display area while moving along a spherical surface with a preset radius; and

an information processing apparatus that generates a three-dimensional mura figure from the plurality of images acquired by the non-uniformity detection unit, by associating a feature value of the display mura in each of the images with a position where the image is acquired, and causes a mura superimposed image to be displayed such that the three-dimensional mura figure viewed from a designated observation angle can be superimposed on a virtual plane viewed from the designated observation angle, wherein

the information processing apparatus includes;

a memory device that obtains an elevation angle and an azimuth angle as the position, and stores two kinds of three-dimensional mura figure data one of which is three-dimensional mura figure data specified by a feature value of the display mura at each of the positions, and the other of which is three-dimensional mura figure data having coordinates converted into a Cartesian coordinate system from those in the former three-dimensional mura figure data;

a controlling device that calculates the three-dimensional mura figure viewed when the virtual plane is viewed from the observation angle, and generates the mura superimposed image in which the three-dimensional mura figure is superimposed on the virtual plane; and

a control I/O unit section that outputs the three-dimensional mura figure superimposed on the virtual plane, and

the non-uniformity detection unit includes;

a camera that acquires the images;

a camera driving unit that moves the camera to such positions that the images of the display mura can be captured; and

a stage driving unit that positions the display mura, targeted for the image capturing, within a field of view of the camera.

10. The display inspection apparatus according to claim 9, wherein

the controlling device generates the three-dimensional mura figure as a three-dimensional mura figure curved plane which smoothly connects the three-dimensional mura figure data or gives a minimal residual.

11. A device-executable program, tangibly embodied in a non-transitory computer readable medium, for a non-uniformity evaluation apparatus to execute a non-uniformity evaluation method for evaluating a display mura of a display device, the program causing the non-uniformity evaluation apparatus to execute the steps of:

capturing an image of a display area of the display device set within a field of view of a camera;

extracting display muras from the image of the display area thus captured, the display mura targeted for three-dimensional mura figure data generation;

capturing images of each of the display muras at different elevation angles and azimuth angles with respect to the camera, generating three-dimensional mura figure data by calculating a feature value of the display mura at each pair of an observation angle and the azimuth angle, and generating a three-dimensional mura figure curved plane from the three-dimensional mura figure data; and

calculating the three-dimensional mura figure curved plane viewed when the display area is viewed from the observation angle, and displaying a mura superimposed image in which the three-dimensional mura figure curved plane is superimposed on a virtual plane that represents the display area, the step of displaying a mura superimposed image further including the steps of;

superimposing a region having a feature value equal to or higher than a threshold set for the display mura, as a portion different in hue or luminance, on the three-dimensional mura figure curved plane at a position in a bottom surface of the three-dimensional mura figure;

defining a handle for rotating the virtual plane; and

rotating the virtual plane in response to an operation performed on the handle, and updating the mura superimposed image by recalculating the three-dimensional mura figure curved plane viewed when the display area is viewed from the observation angle according to the rotation.