JP4518975B2 - Display quality measuring device for image display device - Google Patents

Description

  The present invention relates to a display quality measuring device for an image display device that measures the display quality of an image display device such as a liquid crystal display, a cathode ray tube, or a plasma display.

  The display quality evaluation items of the image display device include the brightness, contrast, correctness of displayed colors, brightness spots, color spots, etc., where test patterns are displayed on the display screen. The above-mentioned evaluation items were measured by the display quality measuring device.

  A conventional display quality measuring apparatus for an image display apparatus will be described with reference to FIG.

  In FIG. 6, reference numeral 1 denotes a display screen of the image display device. A CCD camera device 2 is arranged facing the display screen 1, and a light reception signal from the CCD camera device 2 is sent to a computer 3 such as a PC. It is supposed to be done.

  As shown in FIG. 7, the CCD camera device 2 is provided with a light receiving lens 4, and divided mirrors 5, 6, and 7 that divide the light transmitted through the light receiving lens 4 into three parts. 1/3 is transmitted and 2/3 is reflected, the split mirror 6 is transmitted through 1/2 and 1/2 is reflected, and the split mirror 7 is totally reflected. Color filters 8, 9, and 10 for separating the three primary colors are provided so as to face the divided mirrors 5, 6, and 7, respectively. The color filter 8 transmits red light, and the color filter 9 transmits green light. The color filter 10 transmits blue light.

  Further, two-dimensional CCD sensors 11, 12, and 13 are provided so as to face the color filters 8, 9, and 10, respectively. The image is formed. Further, the positions of the pixels of the two-dimensional CCD sensors 11, 12 and 13 are associated with the positions in the display screen 1.

  Light receiving signals from the two-dimensional CCD sensors 11, 12 and 13 are sent to the computer 3.

  The display quality of the display screen 1 is measured by selecting a measurement point on the display screen 1 in the computer 3 and using the two-dimensional CCD sensors 11, 12, 13 corresponding to the positions of the measurement points. The brightness (luminance) of the measurement point is measured by calculating the amount of light received at each pixel at the same position by the computer 3, and the color (color development) is measured by calculating the ratio of the amount of light received at each pixel. The

  The measurement point is moved at a required pitch, brightness and color are measured over the entire screen of the display screen 1, and compared with data on the brightness and color of the image displayed on the display screen 1. Thus, the display quality of the display screen 1 is measured.

  FIG. 8 shows a display quality measuring apparatus of another conventional image display apparatus, in which the display quality of an image is measured using a luminance / colorimeter 15.

  The luminance chromaticity meter 15 is supported by an XZ table 16 so as to be movable in two directions of XZ parallel to the display screen 1 so that the optical axis is perpendicular to the display screen 1. ing. That is, the luminance and colorimeter 15 is supported by a Z slider 17, the Z slider 17 is supported by an X slider 18 so as to be movable in a vertical direction, and the X slider 18 is supported by a table 19 so as to be movable in a horizontal direction. ing. The reason why the optical axis of the luminance chromaticity meter 15 is perpendicular to the display screen 1 is that the luminance and the color tone change as the optical axis is inclined with respect to the display screen 1. In particular, in a liquid crystal display device or the like, it is considered that the measured value is affected by the tilt of the optical axis.

  The movement point of the Z slider 17 and the X slider 18 is determined so that the point at which the optical axis of the luminance / colorimeter 15 intersects the display screen 1 becomes a measurement point, and the measurement point extends over the entire area of the display screen 1. Has been.

  FIG. 9 shows an example of the luminance chromaticity meter 15. Light from the measurement point is imaged on the spectroscopic reflecting mirror 22 by the condenser lens 21, and the spectroscopic reflecting mirror 22 is diffused so as to correspond to the wavelength. The reflected light is received by a one-dimensional sensor 23, for example, a line sensor. By detecting the total amount of light from the one-dimensional sensor 23, the luminance of the measurement point is measured, and by detecting the light reception distribution of the one-dimensional sensor 23, the color is measured.

  In the above-described conventional display quality measuring device of the image display device, the display quality is measured based on the individual received light signals from the respective two-dimensional CCD sensors 11, 12, 13 and the two-dimensional CCD sensor. The individual difference of 11, 12, and 13 and the characteristics of the color filter affect the measurement accuracy. Furthermore, pixel performance within a single CCD sensor, such as sensitivity uniformity, also affects measurement accuracy. Further, since light from the periphery of the display screen 1 is incident on the CCD camera device 2 at an angle, an error due to the angle is included in the measurement result.

  In the latter display quality measuring device, the display luminance is measured for the entire area of the display screen 1 with the same luminance chromaticity meter 15, so that a decrease in measurement accuracy due to the luminance chromaticity meter 15 is avoided. Can do. However, since it is necessary to move the heavy luminance chromaticity meter 15 over the entire area of the display screen 1, the XZ table 16 becomes large. Particularly, in recent years, the display screen 1 has been increased in size, and the XZ table 16 is large and expensive. Further, since the measurement involves the movement of the luminance chromaticity meter 15 at each measurement point, it takes a long time for the measurement.

  In view of such a situation, the present invention provides a display quality measuring device for an image display device that can measure the display quality of the image display device with high accuracy and can perform measurement simply and efficiently.

  The present invention relates to a measurement light guide part provided facing a display screen, a measurement light light path changing part provided facing the measurement light guide part, and a luminance color for a light beam from the measurement light light path changing part. A luminance colorimeter for measuring the degree of light, and the measurement light guide unit guides a light beam emitted from a measurement point in the display screen in a vertical direction to the measurement light beam path changing unit, and the measurement light beam path changing unit Deflects the optical path so that the luminous flux from the measurement light guide is incident on the luminance and colorimeter, and changes the optical path between the measurement light guide and the measurement light path changer to change the position of the measurement point. The present invention relates to a display quality measurement device for an image display device that can be changed, and the measurement light guide unit relates to a display quality measurement device for an image display device that is a Fresnel lens that focuses measurement light on the measurement light optical path changing unit. Also, required interval and required number for the display screen Measurement points are set, and the measurement light guide is related to the display quality measurement device of the image display device which is a prism arranged corresponding to the measurement points, and the required interval and the required number of measurement points with respect to the display screen Is set, and the measurement light guide is an optical fiber provided corresponding to the measurement point, and the incident end of the optical fiber is perpendicular to the display screen. The measurement light path changing unit includes a rotatable first scanning mirror and a second scanning mirror that change a light path between the measurement light path changing unit and the measurement light guide, The optical path deflection direction by the first scanning mirror and the optical path deflection direction by the second scanning mirror are related to a display quality measuring device of an image display device, and the measuring optical path changing unit is a first reflection A mirror and a second reflecting mirror, The first reflecting mirror and the second reflecting mirror are provided so as to rotate integrally, the second reflecting mirror is disposed at the center of rotation, and the first reflecting mirror and the second reflecting mirror are connected to the first reflecting mirror. When the measurement light is incident at a predetermined angle, the second reflecting mirror is related so as to reflect the measurement light in accordance with the optical axis of the luminance and colorimeter, and the exit end of the optical fiber is connected to the first end. The present invention relates to a display quality measuring device of an image display device that is arranged so that measuring light is incident on a reflecting mirror at a predetermined angle. Further, the measuring light is emitted so that only one of a plurality of optical fibers is emitted. The present invention relates to a display quality measuring device of an image display device provided with a shutter for selecting an optical fiber at an end.

  According to the present invention, the measurement light light guide provided to face the display screen, the measurement light light path change part provided to face the measurement light light guide, and the light flux from the measurement light light path change part A luminance chromaticity meter for measuring luminance chromaticity, wherein the measurement light guide unit guides a light beam emitted in a vertical direction from a measurement point in the display screen to the measurement light optical path changing unit, and the measurement light optical path The changing unit deflects the optical path so that the light beam from the measurement light guide unit is incident on the luminance chromaticity meter, and changes the optical path between the measurement light guide unit and the measurement light optical path change unit. Since the position can be changed, the luminance and colorimeter measures the measurement light emitted vertically from the measurement point, and can be measured by the same optical sensor, so the display quality of the image display device can be measured with high accuracy. Yes, the measuring optical path changing unit The display need not be moved along the screen, improves the response speed as well as a possible decrease can be miniaturized moving parts, exhibits excellent effects such as the measurement time can be shortened.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  A first embodiment will be described with reference to FIG.

  In FIG. 1, the same components as those shown in FIGS. 6 and 8 are denoted by the same reference numerals.

  The display quality measuring device for an image display device according to the present invention is mainly composed of a luminance chromaticity meter 15, a measuring light optical path changing unit 25, a measuring light guiding unit 26, and an arithmetic unit 27.

  The measurement light guide 26 guides the measurement light emitted vertically from the display screen 1 to the measurement light path changing unit 25. For example, a Fresnel lens 28 is used. It is wider than the surface projected on the Fresnel lens 28. The Fresnel lens 28 has an optical axis perpendicular to the display screen 1, and collects a light beam (measurement light) parallel to the optical axis from the display screen 1 on the measurement light optical path changing unit 25. Therefore, the focal length f to the optical center of the measuring light path changing unit 25 is provided.

  The measurement light path changing unit 25 includes a first scanning unit 29 and a second scanning unit 31. The first scanning unit 29 includes a first scanning mirror 33 having a rotation axis 32 orthogonal to the optical axis of the luminance / colorimeter 15 and a first scanning actuator for rotating the first scanning mirror 33 via the rotation axis 32. For example, a motor capable of controlling the rotation angle is used as the first scanning actuator 34. By rotating the first scanning mirror 33 by the first scanning actuator 34, for example, in the drawing, the measurement point can be scanned in the X direction.

  The second scanning unit 31 has a configuration equivalent to that of the first scanning unit 29, and includes a second scanning mirror 35, a second scanning actuator 36, etc., and the second scanning mirror 35 is the first scanning mirror. The rotation shaft 37 is orthogonal to the 33 rotation shafts 32. Therefore, in the second scanning unit 31, the measurement point can be scanned in the Z direction by rotating the second scanning mirror 35 by the second scanning actuator. Since the first scanning mirror 33 and the second scanning mirror 35 need only reflect the measurement light, the reflecting surface may be small, and the first scanning mirror 33 and the second scanning mirror 35 are small and light. The optical axis is bent by the first scanning mirror 33. If the plane including the optical axes before and after the first scanning mirror 33 is the A plane and the plane including the optical axes before and after the second scanning mirror 35 is the B plane, the A plane and B By making the surface substantially orthogonal, the polarization components of the light cancel each other and the influence on the measurement of polarization can be removed.

  Although not shown, the measurement light path changing unit 25 drives the first scanning actuator 34 and the second scanning actuator 36 at a predetermined angle and a predetermined speed in response to a command from the arithmetic unit 27, and is synchronized. The first scanning actuator 34 and the second scanning actuator 36 have a drive control unit. The first scanning actuator 34 and the second scanning actuator 36 include the first scanning mirror 33 and the second scanning actuator 36, respectively. An angle detector, such as an encoder, for detecting the rotation angle of the scanning mirror 35 is connected, and an angle detection signal from the encoder is output to the arithmetic unit 27.

  The arithmetic device 27 is represented by, for example, a personal computer (PC), and a sequence program for driving the first scanning actuator 34 and the second scanning actuator 36 is stored in a storage unit (not shown) of the arithmetic device 27. Further, the luminance and chromaticity of the measurement point are calculated based on the signal from the luminance chromaticity meter 15, or the luminance distribution, chromaticity distribution or reference value of the display screen 1 is calculated from the calculation result. A measurement program for calculating a luminance deviation and a chromaticity deviation and displaying them on the display unit of the arithmetic unit 27 as necessary is stored. The luminance chromaticity meter 15 is the same as that shown in FIG.

  As described above, a vertical light beam (measurement light) emitted from an arbitrary position (arbitrary measurement point) on the display screen 1 enters the Fresnel lens 28, and the second scanning mirror is transmitted by the Fresnel lens 28. It is deflected so as to be incident on 35. The measurement light reflected by the second scanning mirror 35 is reflected by the first scanning mirror 33 so as to coincide with the optical axis of the luminance / colorimeter 15. The angle of the second scanning mirror 35 and the angle of the first scanning mirror 33 are determined so that the measurement light from the display screen 1 is reflected by the second scanning mirror 35 and the first scanning mirror 33 and the luminance chromaticity meter. The second scanning actuator 36 and the first scanning actuator 34 are driven synchronously so that the relationship is established.

  When the first scanning actuator 34 and the second scanning actuator 36 are driven and the first scanning mirror 33 and the second scanning mirror 35 are rotated, the measurement light optical path changing unit 25 and the measurement light guiding unit 26 are rotated. The optical path between them is changed, and the measurement points move in the X direction and the Z direction at predetermined intervals. The measurement point is selected by changing the optical path. The rotation direction of the first scanning mirror 33 and the second scanning mirror 35 only needs to be orthogonal to the scanning direction, and the scanning direction is not limited to the X direction and the Z direction.

  The measurement light from the selected measurement point is incident on the luminance chromaticity meter 15 via the measurement light guide unit 26 and the measurement light optical path changing unit 25. From the incident measurement light, the luminance chromaticity meter 15 Measure brightness and chromaticity.

  By selecting measurement points over the entire display screen 1, luminance and chromaticity are calculated over the entire display screen 1.

  The arithmetic unit 27 calculates the measurement results of the luminance distribution, chromaticity distribution, etc. of the display screen 1 based on the luminance and chromaticity measurement signals from the luminance chromaticity meter 15 at the measurement points over the entire surface of the display screen 1. Then, the luminance, chromaticity or luminance distribution, chromaticity distribution, etc. of each measurement point are displayed on the display unit of the arithmetic unit 27.

  In the first embodiment, the brightness and chromaticity are measured with respect to the vertical measurement light from the measurement point, and since the measurement is performed by the same light receiving sensor, accurate measurement is possible, and the small and light weight of the first light is measured. Since the measurement point can be moved by rotating the first scanning mirror 33 and the second scanning mirror 35, the responsiveness is good and display quality measurement can be completed in a short time.

  FIG. 2 shows a second embodiment. In FIG. 2, the same components as those shown in FIG.

  Similarly to the first embodiment, the second embodiment is mainly configured by a luminance chromaticity meter 15, a measurement light optical path changing unit 25, a measurement light light guiding unit 26, and an arithmetic unit 27. The luminance and chromaticity meter 15, the measurement light optical path changing unit 25, and the arithmetic unit 27 are the same as those in the first embodiment, and thus the description thereof is omitted.

  The measurement light guide 26 in the second embodiment is constituted by a prism group in which wedge-shaped prisms are combined.

  A light guide prism 41 is formed by a pair of first wedge prism 38 and second wedge prism 39, and the light guide prism 41 makes vertical measurement light from the display screen 1 incident on the second scanning mirror 35.

  On the display screen 1, a required location is set as a measurement point, for example, the measurement point is set at a predetermined interval including four corners and the center, and the light guide prism 41 is provided for each setting point.

  Since the first wedge prism 38 and the second wedge prism 39 need only transmit the measurement light, they may be small, and the first wedge prism 38 and the second wedge prism 39 may be integrated. Further, the first wedge prism 38 and the second wedge prism 39 may be disposed on one transparent plate, and the light guide prism 41 is disposed at a position facing the measurement point. .

  The first scanning mirror 33 and the second scanning mirror 35 are rotationally controlled so that the measurement light from the light guide prism 41 is incident on the luminance chromaticity meter 15.

  The light guide prism 41 may be a part cut out from a portion corresponding to the measurement point of the Fresnel lens 28 shown in FIG.

  3 to 5 show a third embodiment. In the third embodiment, an optical fiber 42 is used as the measurement light guide 26. Since the arithmetic unit 27 is the same as in the first and second embodiments, the illustration is omitted.

  The optical fibers 42 are used in the number corresponding to a predetermined number of measurement points, the measurement light incident ends of the optical fibers 42 are opposed to the measurement points, and the optical axis of the incident end portion 42a is relative to the display screen 1. It is vertical. Accordingly, a vertical light beam (measurement light) emitted from the measurement point is incident on each optical fiber 42.

  The exit end of the optical fiber 42 is guided to the measurement light optical path changing unit 25, and the optical path is deflected by the measurement light optical path changing unit 25 so as to enter the luminance chromaticity meter 15.

  4 and 5, the measurement optical path changing unit 25 will be described.

  In the figure, reference numeral 43 denotes an emission optical axis 43 of the optical fiber 42. A first reflecting mirror 44 is disposed on the emission optical axis 43, and the reflected optical axis of the first reflecting mirror 44 and the luminance color are shown. A second reflecting mirror 45 is disposed at a position that is the intersection of the optical axes of the photometer 15, and the measurement light incident on the first reflecting mirror 44 from the exit optical axis 43 is transmitted through the first reflecting mirror 44 and the first reflecting mirror 44. The light path is deflected by the two reflecting mirrors 45 and is incident on the luminance chromaticity meter 15.

  The first reflecting mirror 44 and the second reflecting mirror 45 are supported by a reflecting mirror support 46, and the reflecting mirror support 46 is rotatable. The second reflecting mirror 45 is at the center of rotation of the reflecting mirror support 46, and the first reflecting mirror 44 and the second reflecting mirror 45 rotate together, and the first reflecting mirror 44 and the second reflecting mirror 45 are rotated. Is constant regardless of the rotation of the reflector support 46, and when the measurement light is incident on the first reflector 44 at a set angle, the second reflector 45 The reflected measurement light coincides with the rotation center of the reflector support 46, that is, the optical axis of the luminance / colorimeter 15.

  The reflector support 46 has, for example, a ring shape, and teeth constituting a gear are formed on the outer peripheral surface, and a drive gear 48 is provided so as to mesh with the teeth. The drive gear 48 is an optical path. The switching actuator 49 is intermittently driven at a predetermined angular pitch. As the optical path switching actuator 49, for example, a stepping motor capable of controlling the rotation angle is used.

  The exit end portion 42b of the optical fiber 42 is disposed at an angular pitch (for example, α) equally divided by the number of the optical fibers 42 with respect to the rotation center of the first reflecting mirror 44, and further, the exit The exit optical axis 43 of the end 42b is set to have a predetermined incident angle with respect to the first reflecting mirror 44. Accordingly, the exit optical axes 43 of the exit end portion 42b are tangents circumscribing the same circle.

  The measurement light emitted from the exit end 42b is reflected by the first reflecting mirror 44, and the measurement light reflected by the first reflecting mirror 44 is reflected by the second reflecting mirror 45. The posture of the first reflecting mirror 44 is set so as to coincide with the optical axis of the luminance / colorimeter 15.

  Thus, the optical fiber 42 is intermittently rotated by α or an integer multiple of α by the optical path switching actuator 49 via the drive gear 48 and the reflector support 46. The measurement light emitted from the light can be appropriately switched and made incident on the luminance chromaticity meter 15.

  The reflector support 46 or the optical path switching actuator 49 is provided with an angle detector (not shown) such as an encoder, and the arithmetic unit 27 determines which optical fiber 42 based on a signal from the angle detector. That is, it is possible to determine which measurement point from which the measurement light is incident on the luminance / colorimeter 15.

  In the third embodiment, the first reflecting mirror 44 and the second reflecting mirror 45 may be small, and the reflecting mirror support 46, the driving gear 48, and the optical path switching actuator 49 are reduced in size and weight. It is possible to change the optical path at high speed and to perform efficient display quality measurement.

  Further, the optical path may be switched by a shutter when the optical fiber 42 is used as the measurement light guide 26. As the shutter, a liquid crystal shutter may be arranged facing the exit end face of each exit end 42b, and the optical path may be changed by turning the shutter on / off.

  Alternatively, in FIG. 4, a shutter plate may be provided on the reflecting mirror support 46 instead of the first reflecting mirror 44 and rotated integrally with the second reflecting mirror 45. The shutter plate is provided with a shutter hole that allows measurement light to pass therethrough, and only the measurement light from the optical fiber 42 in which the shutter hole matches the emission end face 42 b is guided to the second reflecting mirror 45. In this case, the emission end portion 42 b is arranged and supported so that the emission optical axis 43 has a predetermined relationship with the second reflecting mirror 45. For example, the exit end 42b is disposed on a conical curved surface whose apex coincides with the second reflecting mirror 45.

1 is a schematic configuration diagram illustrating a first embodiment of the present invention. It is the structure schematic which shows the 2nd Embodiment of this invention. It is the structure schematic which shows the 3rd Embodiment of this invention. It is a schematic perspective view of the measurement light optical path change part in this 3rd Embodiment. It is a plane layout view of the measurement light path changing unit. It is a schematic block diagram which shows an example of a prior art example. It is the schematic of the CCD camera apparatus in this prior art example. It is a schematic block diagram which shows the other example of a prior art example. It is the schematic which shows a luminance chromaticity meter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display screen 15 Luminance colorimeter 25 Measurement light optical path change part 26 Measurement light light guide part 27 Arithmetic apparatus 28 Fresnel lens 29 1st scanning unit 31 2nd scanning unit 33 1st scanning mirror 34 1st scanning actuator 35 2nd scanning mirror 36 Second scanning actuator 38 First wedge prism 39 Second wedge prism 41 Light guiding prism 42 Optical fiber 42a Incident end 42b Ejecting end 43 Ejecting optical axis 44 First reflecting mirror 45 Second reflecting mirror 46 Reflecting mirror support

Claims (6)

  Measuring light chromaticity is measured for a measurement light light guide provided opposite to the display screen, a measurement light light path changing part provided opposite to the measurement light light guide, and a light flux from the measurement light light change part. A luminance chromaticity meter, wherein the measurement light guide unit guides a light beam emitted from a measurement point in the display screen in a vertical direction to the measurement light beam path changing unit, and the measurement light beam path changing unit is the measurement light beam The position of the measurement point can be changed by deflecting the optical path so that the light beam from the light section is incident on the luminance and colorimeter and changing the optical path between the measurement light guide section and the measurement light optical path changing section. A display quality measuring device for an image display device.   The display quality measuring device for an image display device according to claim 1, wherein the measurement light guide is a Fresnel lens that focuses measurement light on the measurement light path changing unit.   2. The display quality measuring device for an image display device according to claim 1, wherein a required interval and a required number of measurement points are set for the display screen, and the measurement light guide is a prism arranged corresponding to the measurement points.   A required interval and a required number of measurement points are set for the display screen, the measurement light guide is an optical fiber provided corresponding to the measurement point, and an incident end of the optical fiber is on the display screen. The display quality measuring device for an image display device according to claim 1, which is perpendicular to the display device.   The measurement optical path changing unit includes a rotatable first scanning mirror and a second scanning mirror that change an optical path between the measurement optical path changing unit and the measurement optical light guide unit, and the first scanning mirror is provided. 2. The display quality measuring device for an image display device according to claim 1, wherein the deflection direction of the optical path by the light source is orthogonal to the deflection direction of the optical path by the second scanning mirror.   The measuring light path changing unit includes a first reflecting mirror and a second reflecting mirror, and the first reflecting mirror and the second reflecting mirror are provided so as to rotate together, and the second reflecting mirror rotates. The first reflecting mirror and the second reflecting mirror are arranged in the center, and when the measuring light is incident on the first reflecting mirror at a predetermined angle, the second reflecting mirror transmits the measuring light to the luminance colorimeter. The display quality of the image display device according to claim 4, wherein the display end quality of the image display apparatus is arranged so that the measurement light is incident at a predetermined angle on the first reflecting mirror. measuring device.

Images