JP4644595B2 - Display evaluation apparatus, evaluation method, and program - Google Patents

Description

  The present invention relates to an evaluation apparatus, an evaluation method, and a program for evaluating unevenness of a display such as a liquid crystal, and more particularly to improvement of a technique for quantifying unevenness without depending on a problem of a luminance change caused by the expected angle of display.

  Conventionally, when evaluating unevenness of a display, as shown in FIG. 7, the display is photographed and imaged, and the unevenness is quantified by image processing.

  By the way, depending on the unevenness, the unevenness is easily seen when observed from a specific viewing angle. In such a case, the light leakage varies depending on the position of the screen, and the unevenness is accurately detected even when the image processing is simply performed. In some cases, it could not be quantified. Specifically, as shown in FIG. 7, when measuring the unevenness, the measurement position P is measured by measuring the imaging position on the display D from the direction inclined from the direction perpendicular to the surface of the display D. There is an imaging position a1 near the point P and an imaging position a2 far away. At this time, in the state measured from the measurement point P, the image pickup position a1 and the image pickup position a2 are measured with different light leaks, and this is an improvement in that it cannot be accurately quantified. There was room.

  Therefore, conventionally, the luminance gradient is removed by spatial frequency processing or the like, but there is a disadvantage that unevenness itself is reduced.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a display evaluation apparatus and an evaluation method capable of quantifying unevenness without depending on the problem of luminance change caused by the expected angle of display. And providing a program.

The above object of the present invention is achieved by the following configurations.
(1) An evaluation device for quantifying display unevenness,
An imaging unit that captures a partial image of the display for each of a plurality of imaging positions,
Means for interpolating the image information in the imaging area for each imaging position of the display imaged by the imaging unit, a display rotation mechanism capable of changing the angle of the surface to be measured of the display, and the display An evaluation apparatus comprising: means for generating a luminance image when measured from a certain direction and quantifying unevenness from the luminance image.
(2) An evaluation method for quantifying display unevenness,
A part of the image of the display is imaged by changing the imaging direction of the imaging unit by changing the angle of the measured surface of the display by the imaging unit for each of a plurality of imaging positions,
A luminance image when the display is measured from a certain direction is generated by interpolating the image information in the imaging region for each imaging position of the display captured by the imaging unit, and from the luminance image An evaluation method characterized by quantifying unevenness.

  In the present invention, a display which is an evaluation target is imaged at a plurality of imaging positions by an imaging unit, and image information is acquired for each imaging position. Then, by interpolating the obtained image information for each imaging position, luminance variation due to the difference in the position of the display, which has been a problem in the past when measuring the display from only a specific imaging position, The influence can be suppressed. Then, by evaluating the luminance image obtained after the interpolation calculation and measured from a certain direction, the unevenness can be more accurately quantified while taking the luminance variation into consideration.

  Further, when the imaging unit is controlled to move parallel to the surface to be measured, a plurality of imaging positions are determined on a two-dimensional plane parallel to the surface to be measured, and a part of the display is moved by the imaging unit at each imaging position. An image can be taken. Then, by acquiring the image information corresponding to each imaging position for each imaging position, the entire display can be stored in the imaging area, and by interpolating these multiple pieces of image information, at the position on the display, It is possible to prevent occurrence of bias in image information due to overlapping imaging and occurrence of a part that cannot be imaged.

  Furthermore, if the angle of the surface to be measured of the display can be changed, image information can be acquired at a plurality of imaging positions while changing the angle of the display during measurement. By interpolating the acquired plurality of pieces of image information, it is possible to take into account the influence of luminance variation according to the expected angle between the imaging unit and the imaging position, and to more accurately quantify display unevenness.

  ADVANTAGE OF THE INVENTION According to this invention, the display evaluation apparatus, the evaluation method, and program which can quantify nonuniformity can be provided, without depending on the problem of the brightness change resulting from the prospective angle | corner of a display.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram for explaining the configuration of a first embodiment of a display evaluation apparatus according to the present invention. FIG. 2 is a diagram for explaining a state of the evaluation device of FIG. 1 as viewed from above.

  The display evaluation apparatus 10 includes an imaging unit 21 that captures an image of a measurement target surface of a display 11 that is an evaluation target. The imaging unit 21 has a function capable of imaging a part of the measured surface of the display 11 as an imaging region at an arbitrary imaging position, and a CCD camera or the like can be used. The imaging unit 21 can image the entire surface to be measured of the display 11 by imaging at each of a plurality of imaging positions.

  The display 11 is fixed on a support base, a wall, and a stage (not shown).

The evaluation apparatus 10 includes an imaging position adjustment mechanism that can move and control the imaging unit 21 in parallel with the surface to be measured of the display 11.
The developing position adjusting mechanism of the evaluation apparatus 10 is attached to the first shaft 12 that guides the imaging unit 21 in the lateral direction (the arrow x direction in FIG. 1) with respect to the display 11 and to be movable in the axial direction of the first shaft 12. A first clamp 13 that can fix the imaging unit 21, a second clamp 15 that is fixed to one end of the first shaft 12, the second clamp 15, and the display 11. And a second shaft 14 for guiding in the vertical direction (the direction of arrow y in FIG. 1). A lower end portion (lower end portion in FIG. 1) of the second shaft 14 is fixed by a pedestal or the like.

  Indicators such as scales and markers may be attached to the first shaft 12 and the second shaft 14 so that the positions of the first clamp 13 and the second clamp 15 and the amount of movement thereof can be viewed.

  The first clamp 13 and the second clamp 15 may use liner guides provided with rolling ball bearings. Further, the first clamp 13 and the second clamp 15 may be configured to be moved by fingers of the operator who performs the evaluation, or may be configured to be moved in the axial direction by the driving unit.

  In the present embodiment, as shown in FIG. 2, the imaging unit 21 is set to move in parallel with the surface to be measured of the display 11.

  At the time of measurement, the imaging unit 21 can adjust the position in the x direction with respect to the display 11 by moving the first clamp 13 in the axial direction of the first shaft 12, and the second clamp 15 can be adjusted in the axis of the second shaft 14. By moving in the direction, the position in the y direction relative to the display 11 can be adjusted.

Next, the control system of the evaluation apparatus 10 will be described.
The evaluation apparatus 10 includes an imaging control unit 32 that gives an instruction for performing imaging to the imaging unit 21 and acquires image information obtained by the imaging unit 21. In addition, the evaluation device 10 acquires a plurality of pieces of image information from the imaging control unit 32 and performs an interpolation calculation based on the plurality of pieces of image information, and a value calculated by the interpolation calculation unit 34. An image generation unit 36 that generates a luminance image of the same quality as when measured from a certain direction is provided. All or a plurality of the imaging control unit 32, the interpolation calculation unit 34, and the image generation unit 36 may be executed by a calculation processing unit such as a personal computer.

  FIG. 3 is a diagram illustrating the relationship between the display and the imaging position of the imaging unit that images the display. FIG. 3 shows a state in which the surface to be measured of the display 11 is viewed from the front. In FIG. 3, the positions in which numbers are circled indicate the imaging positions of the imaging unit.

  In the present embodiment, the plurality of imaging positions T are set to form a square lattice at equal intervals in the vertical direction and the horizontal direction on a two-dimensional plane parallel to the surface to be measured of the display 11. The position of the imaging unit is adjusted by the imaging position adjustment mechanism in the order of the numbers assigned to the imaging positions, and the image information of the imaging area corresponding to each imaging position is acquired by performing imaging for each imaging position.

  Specifically, first, the imaging unit is moved to a position indicated by 1 in the imaging position T and imaging is performed, thereby obtaining image information of the imaging area corresponding to the one imaging position. Thereafter, the image pickup unit is moved to the second image pickup position and image pickup is performed to obtain image information of the image pickup region corresponding to the second image pickup position. Similarly, a plurality of image information (25 pieces in FIG. 3) can be acquired by performing the same operation on the imaging positions T 3 to 25.

  In the present embodiment, the imaging position T is set in a square lattice shape with respect to the surface to be measured, but the interval between the vertical direction and the horizontal direction may be different. However, by setting the imaging position T in a square lattice pattern with respect to the surface to be measured as in the present embodiment, it is possible to reduce the processing load of the interpolation calculation described later. In addition, the number of imaging positions T is not particularly limited, and can be set as appropriate according to the distance h (see FIG. 3) between the imaging unit and the display and the imaging region of the imaging unit. The number of imaging positions T and the positions thereof may be input in advance to the imaging control unit 32, the interpolation calculation unit 34, and other storage units as position information on the xy coordinates.

  Next, the procedure of an evaluation method using the evaluation apparatus of this embodiment will be described with reference to the drawings. FIG. 4 is a flowchart showing a procedure of an evaluation method using the evaluation apparatus of the first embodiment. In the procedure of the evaluation method described below, members having the same configuration / action as those already described are denoted by the same or corresponding reference numerals in the drawing, and the description is simplified or omitted. .

  First, the display 11 is fixed at a predetermined position. As shown in FIGS. 1 and 3, the imaging unit 21 is moved and fixed to one of the imaging positions T defined on a two-dimensional plane parallel to the surface to be measured of the display 11. (Step S11).

  After fixing the position of the imaging unit 21, a signal for executing imaging is transmitted from the imaging control unit 32, and an imaging region on the display 11 at the fixed position of the imaging unit 21 is imaged (step S12).

  After imaging, it is determined whether there is another imaging position T where imaging has not been performed (step S13). If there is an imaging position T where imaging has not been performed, the process proceeds to step S11 and imaging has not been performed. The imaging unit is moved to the imaging position T, and then imaging is performed in the same manner (step S12).

  If it is determined that there is no other imaging position T where imaging has not been performed, the process proceeds to a step (step 14) in which interpolation calculation is performed. In the step of executing the interpolation calculation, the interpolation calculation is performed based on the image information of the display 11 captured at each of the plurality of imaging positions T. The interpolation calculation method will be described with reference to FIG. Here, all the points corresponding to the photographing positions 1 to 25 on the surface to be measured of the display 11 are images when viewed from the vertical direction for each photographing position. Here, for example, point A has information on luminance values captured from the respective directions of the shooting positions 7, 8, 12, and 13, and the luminance when viewed from the vertical direction by two-dimensional interpolation from the values of these four points. A value can be calculated. Furthermore, more accurate interpolation values are calculated by performing two-dimensional nonlinear interpolation including the surrounding measurement positions 1, 2, 3, 4, 6, 9, 11, 14, 16, 17, 18, and 19. Is possible.

  Based on the value obtained by the interpolation calculation, the image generation unit 36 generates a luminance image. An evaluation value can be calculated by generating a luminance image of the same quality as when the display is measured from a certain direction and calculating a quantitative evaluation scale for unevenness based on the luminance image (step S15). . Although the method for calculating the quantitative evaluation scale is not particularly limited, for example, the method disclosed in JP-A-2002-257679 can be applied.

  In the evaluation apparatus 10 and the evaluation method of the present embodiment, the display 11 that is an evaluation target is imaged at a plurality of imaging positions T by the imaging unit 21, and image information is acquired for each imaging position T. Then, by interpolating the obtained image information for each imaging position, the luminance of the display 11 due to the difference in the position of the display 11, which has been a problem in the past when measuring the display 11 only from a specific imaging position, is obtained. The influence of variation can be suppressed. Then, by evaluating the luminance image obtained after the interpolation calculation and measured from a certain direction, the unevenness can be more accurately quantified while taking the luminance variation into consideration.

  Further, when the imaging unit 21 is controlled to move in parallel to the surface to be measured of the display 11 as in the present embodiment, a plurality of imaging positions T are determined on a two-dimensional plane parallel to the surface to be measured, and each imaging is performed. A part of the display 11 can be imaged by the imaging unit 21 at the position T. Then, by acquiring the image information corresponding to each imaging position T for each imaging position, the entire display 11 can be stored in the imaging area, and by interpolating these plural pieces of image information, It is possible to prevent the image information from being biased due to overlapping imaging at the position and the occurrence of a part that cannot be imaged.

  Furthermore, it is good also as a program which has the procedure of the said evaluation method. Specifically, the program captures a part of the image of the display 11 for each of a plurality of imaging positions T by the imaging unit 21, and the image information in the imaging region for each imaging position T of the display 11 captured by the imaging unit 21. Are interpolated, generating a luminance image when the display is measured from a certain direction, and quantifying unevenness from the luminance image. According to such a program, the unevenness can be quantified by the control device connected to the processing device by being executed by the processing device.

Next, the structure of 2nd Embodiment of the evaluation apparatus concerning this invention is demonstrated.
FIG. 5 is a diagram illustrating the configuration of the evaluation apparatus according to the second embodiment. In the embodiments described below, members and the like having the same configuration / action as those already described are denoted by the same or corresponding reference numerals in the drawings, and the description thereof is simplified or omitted.

  In the evaluation apparatus 20 of the present embodiment, the display 31 includes a display rotation mechanism that can change the angle of the surface to be measured with respect to the imaging unit 21. Specifically, the display 31 is attached to a frame portion 24 having a substantially rectangular shape and a pair of shafts 23 provided on the frame portion 24 so as to be rotatable about an axis C2 indicated by a dashed line. In addition, a shaft 22 is provided on the lower side portion of the frame portion 24, and is supported rotatably by an unillustrated rotation driving unit with the axis C1 as a rotation axis. As described above, the shafts 22 and 23 and the frame portion 24 constitute a display rotation mechanism that can tilt the measurement target surface of the display 31 at a predetermined angle so as to be vertically and horizontally oriented.

  The display 31 may be configured such that the operator who performs the evaluation changes the angle with fingers, or the driving force is supplied to the rotation support member by a driving unit (not shown) so that the display 31 is adjusted to a desired angle. It is good also as a structure to rotate.

  The evaluation device 20 includes a control system similar to that of the evaluation device 10 of the first embodiment, that is, an imaging control unit 32 that acquires image information of the imaging unit 21, and a plurality of pieces of image information from the imaging control unit 32. And an interpolation calculation unit 34 that performs an interpolation calculation based on the plurality of pieces of image information, and an image that generates a luminance image of the same quality as that measured from a certain direction based on the value calculated by the interpolation calculation unit 34 And a generation unit 36. The functions of the imaging control unit 32, the interpolation calculation unit 34, and the image generation unit 36 can be the same as those of the evaluation device 10 of the first embodiment.

  The evaluation apparatus 20 has a plurality of images determined on a two-dimensional plane from the imaging unit 21 toward the display 31 in which the measurement target unit is set at an arbitrary angle with the imaging unit 21 fixed at a predetermined position. Imaging is performed at the imaging position. In the present embodiment, the two-dimensional plane that defines a plurality of imaging positions is changed with respect to the surface to be measured of the display 31. The plurality of imaging positions can be arranged in the same manner as in the first embodiment, and may be set in a square lattice pattern at equal intervals in the vertical direction and the horizontal direction between the imaging positions. The interval between and may be different. However, by setting the imaging position in a square lattice pattern with respect to the surface to be measured, it is possible to reduce the processing load of the interpolation calculation described later. The number of imaging positions is not particularly limited, and can be set as appropriate according to the distance between the imaging unit 21 and the display 20 and the imaging region of the imaging unit 21.

  When evaluating the display 31 by the evaluation device 20, the surface to be measured of the display 31 is adjusted by the display rotation mechanism, and imaging is performed for each of a plurality of imaging positions, so that each angle of the surface to be measured of the display 31 is measured. The image information of the imaging area corresponding to each imaging position is acquired.

  Next, the procedure of an evaluation method using the evaluation apparatus of this embodiment will be described with reference to the drawings. FIG. 6 is a flowchart showing the procedure of the evaluation method using the evaluation device 20 of the second embodiment. In the procedure of the evaluation method described below, members having the same configuration / action as those already described are denoted by the same or corresponding reference numerals in the drawing, and the description is simplified or omitted. .

  First, the measurement target surface of the display 31 is set to a predetermined angle (step S21). Then, as shown in FIG. 5, the imaging unit 21 performs imaging for each of a plurality of imaging positions T determined on a two-dimensional plane (step S22).

  After imaging, it is determined whether there is another imaging position T where imaging has not been performed (step S23). If there is an imaging position T where imaging has not been performed, the process proceeds to step S24, and imaging has not been performed. The imaging unit 21 is set at the imaging position T, and then imaging is performed in the same manner (step S22).

  If it is determined that there is no other imaging position T where imaging has not been performed, the process proceeds to step S25, and the imaging of the surface to be measured of the display has been completed within the entire range of angles required for evaluation. Is determined (step S23). If there is an angle where imaging is not performed within the range of angles required for evaluation, the process proceeds to step S21, and the display angle is similarly adjusted by the display rotation mechanism (step S21), and imaging is performed (step). 22).

  If the imaging has been completed in the entire range of angles required for the evaluation, the process proceeds to a step (step 26) for executing an interpolation calculation. In the step of executing the interpolation calculation, the calculation is performed based on the image information of the display 31 in which the surface to be measured is imaged at a plurality of imaging positions T for each predetermined angle. As the interpolation calculation, the same processing as in the first embodiment is performed.

  Then, similarly to the first embodiment, the image generation unit 36 generates a luminance image based on the value obtained by the interpolation calculation. Then, an evaluation value can be calculated by generating a luminance image of the same quality as when the display is measured from a certain direction and calculating a quantitative evaluation scale for unevenness based on the luminance image (step S27). . The method for calculating the quantitative evaluation scale is not particularly limited, and for example, the method disclosed in JP-A-2002-257679 can be applied.

  According to the evaluation apparatus and the evaluation method of the present embodiment, in the same manner as in the first embodiment, by evaluating a luminance image of the same quality as when the display was measured from a certain direction, while taking into account variations in luminance, Unevenness can be quantified more accurately.

  Further, if the angle of the measurement target surface of the display 31 can be changed, image information can be acquired at a plurality of imaging positions T while changing the angle of the display 31 during measurement. By interpolating the acquired plurality of pieces of image information, it is possible to consider the influence of luminance variation according to the expected angle between the imaging unit 31 and the imaging position T, and to quantify the unevenness of the display 31 more accurately. it can.

  Furthermore, it is good also as a program which has the procedure of the said evaluation method similarly to 1st Embodiment. According to such a program, the unevenness can be quantified by the control device connected to the processing device by being executed by the processing device.

It is a figure explaining the structure of 1st Embodiment of the evaluation apparatus of the display concerning this invention. It is a figure explaining the state which looked at the evaluation apparatus of Drawing 1 from the upper part. It is a figure explaining the relationship between a display and the imaging position of the imaging part which images this display. It is a flowchart which shows the procedure of the evaluation method using the evaluation apparatus of 1st Embodiment. It is a figure which shows the structure of the evaluation apparatus of 2nd Embodiment. It is a flowchart which shows the procedure of the evaluation method using the evaluation apparatus of 2nd Embodiment. It is a figure explaining the evaluation method of the conventional display.

Explanation of symbols

10, 20 Evaluation apparatus 11, 31 Display 21 Imaging unit 32 Imaging control unit 34 Interpolation calculation unit 36 Image generation unit

Claims (2)

An evaluation device for quantifying display unevenness,
An imaging unit that captures a part of the image of the display for each of a plurality of imaging positions;
Means for interpolating the image information in the imaging area for each imaging position of the display imaged by the imaging unit, a display rotation mechanism capable of changing the angle of the surface to be measured of the display, and the display An evaluation apparatus comprising: means for generating a luminance image when measured from a certain direction and quantifying unevenness from the luminance image. An evaluation method for quantifying display unevenness,
  A part of the image of the display is imaged by changing the imaging direction of the imaging unit by changing the angle of the measured surface of the display by the imaging unit for each of a plurality of imaging positions,
  A luminance image when the display is measured from a certain direction is generated by performing interpolation calculation on the image information in the imaging region for each imaging position of the display, which is captured by the imaging unit, and from the luminance image An evaluation method characterized by quantifying unevenness.

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