KR102788728B1 - Image instrumentation apparatus - Google Patents

Abstract

An image measuring device includes: a stage on which a display panel is mounted; an image acquisition unit that captures an image of a display surface of the display panel to acquire an image displayed by the display panel; an image reflection unit that reflects the image of the display panel to the image acquisition unit; and an image analysis unit that analyzes at least one of color and brightness information of the acquired image according to an angle at which the image is reflected to determine a viewing angle characteristic of the display panel. The image acquisition unit simultaneously captures images corresponding to a plurality of reflection angles with a single capture.

Description

IMAGE INSTRUMENTATION APPARATUS

The present invention relates to an inspection system for a display device, and more particularly, to an image measuring device and an image measuring system.

The image measuring device captures an image displayed on a display device (display panel) and optically analyzes the captured image. The image measuring device generates image data analyzed for brightness, color, etc., and can further correct pixel defects, image deviation, etc. based on the analyzed image data.

Images output from an image measuring device that captures images of a flat display surface with a single lens of a camera inevitably have deviations in image characteristics due to differences in field of view in the remaining areas excluding the central portion of the image.

One object of the present invention is to provide an image measuring device that acquires image characteristics for multiple viewing angles with a single capture.

However, the purpose of the present invention is not limited to the above-described purposes, and may be expanded in various ways without departing from the spirit and scope of the present invention.

In order to achieve one object of the present invention, an image measuring device according to embodiments of the present invention may include: a stage on which a display panel is mounted; an image acquisition unit that captures an image of a display surface of the display panel to capture an image displayed by the display panel; an image reflection unit that reflects the image of the display panel to the image acquisition unit; and an image analysis unit that analyzes at least one of color and brightness information of an image captured according to an angle at which the image is reflected to determine a viewing angle characteristic of the display panel. The image acquisition unit may simultaneously capture images corresponding to a plurality of reflection angles with a single capture.

In one embodiment, the image acquisition unit may include a camera that acquires a first image using light incident vertically from a target spot of the display surface, and acquires a second image using light reflected from the target spot to the image reflection unit.

In one embodiment, the image reflector may include at least one mirror member positioned within a field of view of the camera.

In one embodiment, the at least one mirror member can be a total reflection mirror comprising a flat reflective surface.

In one embodiment, the total reflection mirror can reflect light of the image of the target point to the image acquisition unit.

In one embodiment, the analysis unit can determine the angle between a vertical axis between the target point and the camera and a light path incident from the target point to the at least one mirror member as a viewing angle for the display panel.

In one embodiment, the image analysis unit may include a characteristic detection unit that analyzes spectral tristimulus values of each of the first and second images to detect image characteristics including information on brightness and color; and a viewing angle characteristic determination unit that compares the first image characteristic of the first image with the second image characteristic of the second image to determine the viewing angle characteristic of the second image with respect to the first image.

In one embodiment, the analysis unit may further include an image correction unit that generates correction parameters reflecting optical characteristics of the mirror member and provides the correction parameters to the viewing angle characteristic determination unit.

In one embodiment, the viewing angle characteristic determining unit can apply the correction parameter to the second image characteristic and compare the second image characteristic to which the correction parameter is applied with the first image characteristic.

In one embodiment, the camera can further acquire a third image, which is a 2D image of the entire display surface including the first image.

In one embodiment, the characteristic detection unit can detect the image characteristic of the third image. The image analysis unit can further include an offset determination unit that compares the first image characteristic with the third image and calculates an image offset applied to an area other than the target point of the display panel.

In one embodiment, the first image may be an image of a frontal view with respect to the target point, and the second image may be an image of a side view corresponding to a preset viewing angle with respect to the target point.

In one embodiment, the at least one mirror member may include a first mirror member and a second mirror member that are arranged opposite each other.

In one embodiment, the image acquisition unit can generate a front view image of the entire display surface that is not reflected by the first and second mirror members, a first side view image of the entire display surface obtained by light having an odd total number of reflections against the first and second mirror members, and a second side view image of the entire display surface obtained by light having an even total number of reflections against the first and second mirror members.

In one embodiment, the first side view image may be an image flipped left and right with respect to the front view image and the second side view image based on the arrangement positions of the first and second mirror members.

In one embodiment, the image analysis unit may compare image characteristics of a first preset target point of the frontal view image, image characteristics of a second preset target point of the first side view image, and image characteristics of a third preset target point of the second side view image to determine viewing angle characteristics corresponding to the first and second side view images.

In one embodiment, the at least one mirror member may further include a curved mirror member that reflects light emitted vertically from the display surface toward the image acquisition unit.

In one embodiment, the image acquisition unit can generate a first front view image of the entire display surface that is not reflected by the first and second mirror elements and the curved mirror element, a side view image of the entire display surface obtained by reflection on one of the first and second mirror elements, and a second front view image obtained by reflection on the curved mirror element.

In one embodiment, the image analysis unit can determine viewing angle characteristics by comparing image characteristics of the first frontal view image with image characteristics of the second frontal view image.

In one embodiment, the image measuring device may further include an image generating unit that generates a test image of a preset grayscale and supplies it to the display panel.

The image measuring device according to embodiments of the present invention can obtain side view images corresponding to multiple viewing angles as well as a front view image by including a plurality of mirror members in a single shot. Accordingly, the time for measuring and compensating viewing angle characteristics for viewing angles of the display panel can be significantly shortened, and the process time can be shortened. Accordingly, the manufacturing cost of the display device can be reduced.

In addition, image characteristics (viewing angle characteristics) according to viewing angles can be calculated relatively accurately by comparative analysis of acquired images. Therefore, image quality can be improved by applying these viewing angle characteristics to the design and operation of a display device.

However, the effects of the present invention are not limited to the effects described above, and may be expanded in various ways without departing from the spirit and scope of the present invention.

FIG. 1 is a drawing showing an image measuring device according to embodiments of the present invention.
FIG. 2 is a drawing showing an example of the image measuring device of FIG. 1.
FIG. 3 is a block diagram showing an example of an image analysis unit included in the image measuring device of FIG. 1.
FIG. 4 is a drawing showing an example of the image measuring device of FIG. 1.
FIG. 5 is a drawing showing an example of the image measuring device of FIG. 1.

Hereinafter, with reference to the attached drawings, a preferred embodiment of the present invention will be described in more detail. The same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

FIG. 1 is a drawing showing an image measuring device according to embodiments of the present invention.

Referring to FIG. 1, the image measuring device (1000) may include a stage, an image acquisition unit (100), an image reflection unit (200), and an image analysis unit (300). In one embodiment, the image measuring device (1000) may further include an image generation unit (400).

The image measuring device (1000) can capture an image displayed by the display panel (10) and analyze the captured image to determine the image characteristics of the display panel (10). Furthermore, the image measuring device (1000) can generate an image correction value or correction parameter based on the analyzed image.

The image acquisition unit (100) can capture an image of the display surface of the display panel (10). The image acquisition unit (100) can acquire an image displayed by the display panel (10). The display panel (10) can be mounted and fixed on a predetermined stage.

The image acquisition unit (100) may include a camera or an image sensor. For example, the camera may include a single lens and may be positioned perpendicular to the display surface of the display panel (10). However, this is merely exemplary, and the configuration of the image acquisition unit (100) is not limited thereto. For example, the image acquisition unit (100) may include sensors that detect images of the display surface in various ways.

The camera of the image acquisition unit (100) has a predetermined field of view (FOV) and can generate and output an image of an area corresponding to the field of view (FOV). That is, the field of view (FOV) of the camera is larger than the display surface of the display panel (10). Accordingly, not only the image of the display surface but also the image of the area included in the field of view (FOV) can be output. The field of view (FOV) can become wider as it gets farther away from the camera.

In one embodiment, the camera of the image acquisition unit (100) can acquire a first image using light that is incident vertically toward the lens from a target point (TS) of the display surface, and can acquire a second image using light that is reflected and incident on the image reflection unit (200) from the target point (TS). That is, the first image and the second image are images that each correspond to the target point (TS). In addition, the image acquisition unit (100) can further acquire a third image that is a 2D image of the entire display surface. For example, light directly emitted from the display surface and light reflected from the image reflection unit (200) can be collected through the lens and provided to the image acquisition unit (100).

The image acquisition unit (100) can provide image data (IMG) including the first to third images to the image analysis unit. In one embodiment, the image data (IMG) can include all image information included within the field of view (FOV). In addition, the image data (IMG) can be displayed on a screen for image analysis as a 2D photo.

Meanwhile, the image characteristics according to the user's viewing angle for the display panel (10) are an important element of the display characteristics. The image displayed on the display device may be perceived differently depending on the user's viewpoint (e.g., the positional relationship between the user and the display device). For example, the image from the front viewpoint is perceived at a relatively small angle relative to the light vertically emitted from the pixel, whereas the image from the side viewpoint is perceived at a relatively large angle relative to the light vertically emitted from the pixel. Accordingly, the range (area) in which one pixel of the image from the side viewpoint is perceived is reduced compared to the image from the front viewpoint, and the brightness of the image from the side viewpoint may be perceived as lower than the brightness of the image from the front viewpoint.

In addition, since the path of the light emitted from the pixel displaying the front view image and the path of the light emitted from the pixel displaying the side view image are different from each other, the side view image may be affected by different light interference from the front view image. For example, the light emitted from the pixel may be perceived as the light penetrating the cover glass, etc. and the light re-reflected through the constructive interference or destructive interference. At this time, the constructive interference or destructive interference of the light may be more severe in the side view image than in the front view image. This constructive interference and destructive interference of the light varies depending on the wavelength of the light, and accordingly, the color of the side view image may be perceived differently from the front view image. For example, when white light is emitted from the display device, white light is perceived from the front, but color changes such as greenish, bluish, and reddish may be perceived from the side due to wavelength shift caused by the difference in the path of the light.

In other words, the brightness and color of the same image may be perceived differently depending on the side viewing angle. Therefore, analysis of the viewing angle characteristics that determine the perceived image depending on the viewing angle is necessary.

Existing image measuring devices cannot simultaneously obtain frontal view image information and image characteristic data according to viewing angle with a single image capture of the display panel. In other words, viewing angle characteristics can be derived using data captured multiple times from multiple angles for the same image.

However, the image measuring device (1000) according to embodiments of the present invention includes an image reflector (200) positioned within a field of view (FOV), so that data for a frontal viewpoint and field of view characteristics (VAD) for various field of view can be calculated with a single capture.

The image reflection unit (200) can reflect the image of the display panel (10) to the image acquisition unit (100). In one embodiment, the image reflection unit (200) can reflect the image of the target point (TS) and make it enter the lens of the camera (the image acquisition unit (100)).

The image reflector (200) may include at least one mirror member positioned within the field of view (FOV) of the camera. Accordingly, an image reflected from the image reflector (200) may be included in the image data (IMG).

The mirror member may be a total reflection mirror in the form of a plane mirror including a flat reflective surface. For example, the mirror member may be an optical mirror having a total reflection rate of 99% or more.

The mirror member may be positioned within the field of view (FOV) to have an appropriate angle with respect to the camera lens and the target point (TS) so that the image of the target point (TS) is incident on the camera lens. The mirror member may perform a function of transmitting an image of a side view (i.e., an image seen from a predetermined field of view) of the display surface (i.e., the target point (TS)) to the image acquisition unit (100).

In one embodiment, a plurality of mirror elements may be respectively arranged to correspond to a plurality of side viewing angles. Each of the mirror elements may perform total reflection. Accordingly, the image acquisition unit (100) may simultaneously acquire images of the display panel (10) corresponding to a plurality of reflection angles (i.e., viewing angles) with a single capture of the object.

The image analysis unit (300) can determine the viewing angle characteristic (VAD) of the display panel (10) by analyzing at least one of the color and brightness information of the acquired image according to the angle at which the image is reflected. The image analysis unit (300) can determine the angle between the vertical axis between the target point (TS) and the camera and the light path incident from the target point (TS) to the mirror member as the viewing angle of the display panel (10).

The image analysis unit (300) may include a colorimeter, a spectrometer, etc. that can perform optical analysis on image data (IMG). However, this is merely exemplary, and the image analysis unit (300) may include various types of optical devices, measuring devices, etc. that can measure brightness information, color coordinate information, color temperature information, etc. from image data (IMG).

In one embodiment, the image analysis unit (300) can additionally reflect the optical characteristics (e.g., light reflection, light refraction, light absorption characteristics) of the mirror member included in the image reflection unit (200) to the image data (IMG). By analyzing the image data (IMG) to which the optical characteristics of the mirror member are applied, more precise viewing angle characteristics (VAD) can be derived. The viewing angle characteristics (VAD) can be provided to an external device such as a memory or a correction device.

The image generation unit (400) can generate a test image of preset gradation and supply it to the display panel (10). For example, a control unit included in the image analysis unit (300) can generate a control signal (CON) that controls the operation of the image generation unit (400) and provide the control signal (CON) to the image generation unit (400). The image generation unit (400) can supply an image signal for calculating a viewing angle characteristic (VAD) and other image characteristics to the display panel (10) in response to the control signal (CON).

As described above, the image measuring device (1000) according to embodiments of the present invention can obtain not only a frontal view image but also side view images corresponding to a plurality of viewing angles by taking a single shot using a plurality of mirror members. Accordingly, the time for measuring and compensating for viewing angle characteristics for viewing angles of the display panel (10) can be significantly shortened, and the process time can be shortened.

FIG. 2 is a drawing showing an example of the image measuring device of FIG. 1.

Referring to FIGS. 1 and 2, an image measuring device (1000) includes an image reflection unit (200) including a plurality of mirror members (MR1, MR2, MR3), and can generate image data (IMG) including first to third images (IM1 to IM3) using an image acquisition unit (100).

The display panel (10) may be mounted on a predetermined stage (600). The camera (120) and the target point (TS) of the display panel (10) may be arranged substantially vertically. For example, the target point (TS) may be an area including some pixels in the center of the display surface.

The image data (IMG) illustrated in FIG. 2 may include an image corresponding to the field of view (FOV) of the camera (120). The first image (IM1) may be acquired by light (indicated by L0) incident perpendicularly on the camera (120) from the target point (TS). The first image (IM1) is an image under the condition that the field of view is 0°, and may be a frontal view image.

The entire image of the display surface of the display panel (10) can be acquired as a third image (IM3). In one embodiment, the third image (IM3) can include the first image (IM1).

The image reflector (200) may include first to third mirror elements (MR1 to MR3). Each of the first to third mirror elements (MR1 to MR3) may be positioned within a field of view (FOV).

The second images (IM2) may be images of the target point (TS) acquired by light reflected from the image reflector (200). The second images (IM2) may include a second-first image (IM2-1), a second-second image (IM2-2), and a second-third image (IM2-3) corresponding to each of the first to third mirror members (MR1 to MR3).

The first mirror member (MR1) can reflect the first light (L1) incident from the target point (TS) and provide it to the camera (120). The first light (L1) can be a set of lights emitted from the first mirror member (MR1) among the lights of the image corresponding to the target point (TS). Here, the angle between the vertical axis (corresponding to L0, for example) between the target point (TS) and the camera (120) and the light path incident from the target point (TS) to the first mirror member (MR1) can be determined as the first viewing angle (A1). That is, the first mirror member (MR1) is arranged to correspond to the first viewing angle (A1), and the second-first image (IM2-1) acquired by the reflection of the first mirror member (MR1) can be determined as an image of the target point (TS) viewed from the first viewing angle (A1). For example, the first viewing angle (A1) can correspond to about 15°.

In the output screen of the image data (IMG), the second-first image (IM2-1) can be generated corresponding to an extension of the optical path provided from the first mirror member (MR1) to the camera (120).

The second mirror member (MR2) can reflect the second light (L2) incident from the target point (TS) and provide it to the camera (120). The second mirror member (MR2) is arranged to correspond to the second viewing angle (A2), and the second-second image (IM2-2) acquired by reflection of the second mirror member (MR2) can be determined as an image of the target point (TS) viewed from the second viewing angle (A2). For example, the second viewing angle (A2) can correspond to about 30°.

The third mirror member (MR3) can reflect the third light (L3) incident from the target point (TS) and provide it to the camera (120). The third mirror member (MR3) is arranged to correspond to the third viewing angle (A3), and the second-third image (IM2-3) acquired by reflection of the third mirror member (MR3) can be determined as an image of the target point (TS) viewed from the third viewing angle (A3). For example, the third viewing angle (A3) can correspond to about 60°.

Although the image reflector (200) in FIG. 2 is illustrated as including three mirror elements, the number of mirror elements is not limited thereto. In addition, the position and angle of the mirror elements may be adjusted according to a desired viewing angle.

Meanwhile, although the mirror members are illustrated in FIG. 2 as being arranged on one side of the display panel (10), the positions of the mirror members are not limited thereto. For example, the mirror members may be arranged on the left and right sides of the display panel (10) corresponding to the second viewing angle (A2). In this case, images of the target point (TS) observed from various directions for the same viewing angle can be acquired. Accordingly, viewing angle characteristics (VAD) for various directions corresponding to the same viewing angle can be measured and calculated.

In this way, the image measuring device (1000) according to embodiments of the present invention can obtain not only a front view image but also side view images corresponding to a plurality of viewing angles with a single capture by including the first to third mirror members (MR1 to MR3). Accordingly, the time for measuring and compensating for viewing angle characteristics for viewing angles of the display panel (10) can be significantly shortened, and the process time can be shortened.

FIG. 3 is a block diagram showing an example of an image analysis unit included in the image measuring device of FIG. 1.

Referring to FIGS. 1 to 3, the image analysis unit (300) may include a characteristic detection unit (320) and a viewing angle characteristic determination unit (340). The image analysis unit (300) may further include an image correction unit (360) and an offset determination unit (380).

The characteristic detection unit (320) can detect the image characteristics (IC1 to IC3) of the first to third images (IM1 to IM3) from the image data (IMG), respectively. In one embodiment, the characteristic detection unit (320) can detect the first and second image characteristics (IC1, IC2) including luminance and color information by analyzing the spectral tristimulus values of each of the first and second images (IM1, IM2). The first image characteristic (IC1) can include luminance and color information of the first image (IM1).

In Fig. 3, the second image characteristic (IC2) is described as an image characteristic corresponding to the second-first image (IM2-1). The second image characteristic (IC2) may include brightness and color information of the second-first image (IM2-1).

In one embodiment, the feature detection unit (320) may include a colorimeter, a spectrometer, or the like capable of performing optical analysis on the first to third images (IM1 to IM3).

The viewing angle characteristic determining unit (340) can receive the first and second image characteristics (IC1, IC2) from the characteristic detection unit (320). The viewing angle characteristic determining unit (340) can compare the first image characteristic (IC1) and the second image characteristic (IC2) to determine the viewing angle characteristic (VAD) of the second image (IM2) with respect to the first image (IM1). For example, based on the first image characteristic (IC1), the luminance difference and the measured grayscale difference between the first image (IM1) and the second image (IM2) can be calculated as the viewing angle characteristic (VAD).

In one embodiment, the image correction unit (360) can generate a correction parameter (CP) that reflects the optical characteristics of the mirror member. For example, the image correction unit (360) can generate a correction parameter (CP) that reflects the optical characteristics of the first mirror member (MR1). Depending on the mirror member, the flatness, reflectivity, etc. of the surface may be different. In addition, the reflectivity by wavelength may be different depending on the mirror member. The image correction unit (360) can generate a correction parameter (CP) that reflects the optical characteristics of the mirror member. The correction parameter (CP) can be provided to the viewing angle characteristic determination unit (340).

The viewing angle characteristic determining unit (340) can apply a correction parameter (CP) to the second image characteristic (IC2). Accordingly, the second image characteristic (IC2) can be corrected, and the viewing angle characteristic (VAD) can be calculated more precisely.

In one embodiment, the viewing angle characteristic determination unit (340) can interpolate the viewing angle characteristics (VAD) of preset viewing angles (e.g., the first to third viewing angles (A1 to A3)) to produce viewing angle characteristics (VAD) for all viewing angles.

Additionally, field of view compensation may be performed based on field of view characteristics (VADs).

The offset determination unit (380) can receive the first image characteristic (IC1) and the third image characteristic (IC3), which is the image characteristic of the third image (IM3). As shown in Fig. 2, a field of view is generated in a part of the display surface excluding the target point (TS) from the camera (120). Accordingly, an image deviation due to a field of view difference can be calculated in at least a part of the third image (IM3).

The offset determination unit (380) can compare the third image (IM3) with the first image characteristic (IC1) to calculate the image offset (OF) for the part that is different from the first image characteristic (IC1). The image offset (OF) can be applied to the corresponding area of the display surface. Accordingly, the viewing angle characteristic for the entire display surface can be compensated for by the image characteristic by the frontal viewpoint.

In this way, the image quality of the display device can be improved by the image analysis unit (300) calculating the viewing angle characteristics (VAD) for various viewing angles.

FIG. 4 is a drawing showing an example of the image measuring device of FIG. 1.

In FIG. 4, the same reference numerals are used for components described with reference to FIGS. 2 and 3, and redundant descriptions of these components are omitted.

Referring to FIGS. 3 and 4, the image reflector (200) may include a first mirror member (MR1) and a second mirror member (MR2) that are positioned opposite to each other.

The image acquisition unit (100) can generate a front view image (FV1) of the entire display surface that is not reflected by the first and second mirror members (MR1, MR2). The front view image (FV1) can be an image acquired assuming a viewing angle of 0°. The front view image (FV1) can include a first target point image (TS1) that is an image of a preset target point (TS). Here, the target point (TS) can be an area virtually set on the display surface of the display panel (10). However, this is exemplary, and the target point (TS) can include a plurality of target points. In this case, a viewing angle characteristic (VAD) according to a position within the display surface can be calculated.

Light emitted from the display surface can be reflected by the first and second mirror members (MR1, MR2) and incident on the camera (120).

The image acquisition unit (100) can generate a first side view image (SVI1), which is an image of the entire display surface, obtained by light having an odd number of total reflections on the first and second mirror members (MR1, MR2). In one embodiment, the first side view image (SVI1) can be generated by light (indicated by L2) reflected only on the first mirror member (MR1). The first side view image (SVI1) can be an image corresponding to a first viewing angle (A1'). The first side view image (SVI1) can include a second target point image (TS2), which is an image of a target point (TS). The first side view image (SVI1) can be an image that is flipped left and right with respect to the front view image (FVI) with respect to the first mirror member (MR1).

The image acquisition unit (100) can generate a second side view image (SVI2), which is an image of the entire display surface, obtained by light having an even number of total reflections on the first and second mirror members (MR1, MR2). In one embodiment, the second side view image (SVI2) can be obtained by light (indicated by L3) that is emitted from the display panel (10), reflected by the second mirror member (MR2), and then reflected by the first mirror member (MR1) and is incident on the image acquisition unit (100). That is, the second side view image (SVI2) is an image of the display surface generated by being reflected a total of two times by the first and second mirror members (MR1, MR2). The first side view image (SVI1) can be an image corresponding to the second viewing angle (A2'). The first side view image (SVI1) can include a third target point image (TS3), which is an image of a target point (TS).

The image analysis unit (300) can measure (detect) image characteristics of the first to third target point images (TS1 to TS3). The image analysis unit (300) can compare the image characteristics of the first target point image (TS1) with the image characteristics of the second target point image (TS2) to determine the view angle characteristic (VAD) corresponding to the first view angle (A1'). Similarly, the image analysis unit (300) can compare the image characteristics of the first target point image (TS1) with the image characteristics of the third target point image (TS3) to determine the view angle characteristic (VAD) corresponding to the second view angle (A2').

The method of calculating the field of view characteristics (VAD) using image data (IMG) has been described in detail with reference to Fig. 3, so any redundant description will be omitted.

The third and fourth side view images (SVI3, SVI4) illustrated in FIG. 4 may correspond to images measured from different directions from the first and second side view images (SVI1, SVI2), respectively. For example, the third side view image (SVI3) may be an image observed from a different direction from the third side view image (SVI3) at a first viewing angle (A1') with respect to the display panel (10).

The third side view image (SVI3) may include a fourth target point image (TS4), and the fourth side view image (SVI4) may include a fifth target point image (TS5). The field of view characteristics (VAD) of the third and fourth side view images (SVI3, SVI4) may also be derived through comparison with the first target point image (TS1).

FIG. 5 is a drawing showing an example of the image measuring device of FIG. 1.

In FIG. 5, the same reference numerals are used for components described with reference to FIGS. 2 to 4, and redundant descriptions of these components are omitted.

Referring to FIGS. 3 and 5, the image reflection unit (200) may include a first mirror member (MR1) and a second mirror member (MR2) that are positioned opposite to each other. The image reflection unit (200) may further include a curved mirror member that reflects light emitted vertically from the display surface to the image acquisition unit.

In one embodiment, the image reflector (200) may include a first curved mirror member (CMR1) and a second curved mirror member (CMR2).

The image acquisition unit (100) can generate a first front view image (FVI1) of the entire display surface that is not reflected by the mirror members (MR1, MR2, CMR1, CMR2). The front view image (FVI1) is an image assuming a field of view of 0°.

Additionally, the image acquisition unit (100) can generate a side view image (SVI) of the entire display surface that is acquired by being reflected by one of the first and second mirror members (MR1, MR2). The side view image (SVI) can be an image corresponding to the first viewing angle (A1").

Meanwhile, a field of view from the lens of the camera (120) may exist in the remaining area except for the central area of the display panel (10) (or, the target point (TS) of FIG. 2). Accordingly, distortion due to the field of view may be recognized. For example, light emitted from a predetermined first area (AA) of the display surface is not vertically incident on the camera (120). That is, as illustrated in FIG. 5, field of view angles lower than the second field of view (A2") exist.

The first curved mirror member (CMR1) can reflect light emitted vertically from the first area (AA) and provide it to the camera (120). Accordingly, the image acquisition unit (100) can generate a second frontal view image (FVI2), which is a frontal view image of the first area (AA). In the output screen of the image data (IMG), the second frontal view image (FVI2) can be generated corresponding to an extension of the light path provided from the first curved mirror member (CMR1) to the camera (120) in the field of view (FOV).

Likewise, the second curved mirror member (CMR2) can reflect light emitted vertically from the second region (BB) and provide it to the camera (120). Accordingly, the image acquisition unit (100) can generate a third frontal view image (FVI3) which is a frontal view image of the second region (BB). In the output screen of the image data (IMG), the third frontal view image (FVI3) can be generated corresponding to an extension of the light path provided from the second curved mirror member (CMR2) to the camera (120) in the field of view (FOV).

In one embodiment, the image analysis unit (300) can determine a field of view characteristic (VAD) for a first field of view (A1") by comparing the side view image (SVI) with the first front view image (FVI1). The field of view characteristic (VAD) for the first field of view (A1") can be calculated by the methods described with reference to FIGS. 2 to 4.

The image analysis unit (300) can compare the image characteristics of the first area (AA) of the first frontal view image (FVI1) with the image characteristics of the second frontal view image (FVI2), and calculate the influence of the viewing angle on the first area (AA) based on the result of the comparison. Accordingly, viewing angle characteristics (VAD) of 0° to the second viewing angle (A") can be calculated.

In one embodiment, the image analysis unit (300) can remove the field of view component from the first frontal view image (FVI1) based on a result of comparing the image characteristics of the first area (AA) with the image characteristics of the second frontal view image (FVI2) (and/or a result of comparing the image characteristics of the second area (BB) with the image characteristics of the third frontal view image (FVI3)). For example, the image characteristics of the first area (AA) can be replaced with the image characteristics of the second frontal view image (FVI2) or corrected based on the image characteristics of the second frontal view image (FVI2).

In one embodiment, the image analysis unit (300) can compare the image characteristics of a first frontal view image (FVI1, i.e., a corrected first frontal view image) from which the field of view component has been removed with the image characteristics of a side view image (SVI) to derive the field of view characteristic (VAD) for the first field of view (A1").

That is, the image measuring device of Fig. 5 can precisely measure and calculate the viewing angle characteristics (VAD) for micro viewing angles below the second viewing angle (A"). Therefore, compared to the image measuring device of Fig. 4, the precision and accuracy of the calculated viewing angle characteristics (VAD) for all viewing angles can be further improved.

As described above, the image measuring device (1000) according to embodiments of the present invention can obtain side view images corresponding to multiple viewing angles as well as a front view image by including a plurality of mirror members in a single shot. Accordingly, the time for measuring and compensating viewing angle characteristics for viewing angles of the display panel (10) can be significantly shortened, and the process time can be shortened.

In addition, image characteristics (viewing angle characteristics (VAD)) according to viewing angles can be calculated relatively accurately by comparative analysis of acquired images. Therefore, image quality can be improved by applying these viewing angle characteristics (VAD) to the design and operation of a display device.

Although the present invention has been described above with reference to embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

10: Display panel 100: Image acquisition unit
120: Camera 200: Image Reflector
300: Image analysis section 320: Feature detection section
340: Field of view characteristic determination unit 360: Image correction unit
380: Offset determination unit 400: Image generation unit
1000: Image measuring device TS: Target point
MR1~MR3: Mirror absence CMR1, CMR2: Curved mirror absence

Claims (20)

A stage on which the display panel is mounted;
An image acquisition unit that captures an image of the display surface of the display panel and acquires an image displayed by the display panel;
An image reflection unit that reflects an image of the above display panel to the image acquisition unit; and
An image analysis unit is included to determine the viewing angle characteristics of the display panel by analyzing at least one of color and brightness information of the image obtained according to the angle at which the image is reflected.
The above image acquisition unit simultaneously acquires images corresponding to multiple reflection angles with a single capture,
The above image acquisition unit,
An image measuring device characterized by including a camera that acquires a first image using light that is emitted from a target spot of the display surface and is directly incident vertically without being reflected by the image reflector, and acquires a second image using light reflected from the target spot to the image reflector. delete In the first paragraph, the image reflector,
An image measuring device characterized by including at least one mirror member positioned within the field of view of the camera. An image measuring device according to claim 3, characterized in that the at least one mirror member is a total reflection mirror including a flat reflective surface. An image measuring device, characterized in that in claim 4, the total reflection mirror reflects light of the image of the target point to the image acquisition unit. An image measuring device according to claim 3, characterized in that the image analysis unit determines the angle between the vertical axis between the target point and the camera and the light path incident from the target point to the at least one mirror member as the viewing angle for the display panel. In the 6th paragraph, the image analysis unit,
A characteristic detection unit that analyzes the spectral tristimulus values of each of the first and second images to detect image characteristics including brightness and color information; and
An image measuring device characterized by including a viewing angle characteristic determining unit that compares a first image characteristic of the first image with a second image characteristic of the second image to determine the viewing angle characteristic of the second image with respect to the first image. In the 7th paragraph, the image analysis unit,
An image measuring device further comprising an image correction unit that generates correction parameters reflecting the optical characteristics of the mirror member and provides the correction parameters to the viewing angle characteristic determination unit. An image measuring device, characterized in that in claim 8, the viewing angle characteristic determining unit applies the correction parameter to the second image characteristic and compares the second image characteristic to which the correction parameter is applied and the first image characteristic. An image measuring device, characterized in that in claim 7, the camera further acquires a third image, which is a 2D image of the entire display surface including the first image. In the 10th paragraph, the characteristic detection unit detects the image characteristic of the third image,
The above image analysis unit,
An image measuring device further comprising an offset determining unit that compares the first image characteristic with the third image to calculate an image offset applied to an area other than the target point of the display panel. An image measuring device, characterized in that in the first paragraph, the first image is an image of a frontal view with respect to the target point, and the second image is an image of a side view corresponding to a preset viewing angle with respect to the target point. An image measuring device, characterized in that in claim 3, the at least one mirror member includes a first mirror member and a second mirror member that are arranged opposite to each other. In the 13th paragraph, the image acquisition unit,
An image measuring device characterized by generating a front view image of the entire display surface that is not reflected by the first and second mirror members, a first side view image of the entire display surface obtained by light having an odd total number of reflections against the first and second mirror members, and a second side view image of the entire display surface obtained by light having an even total number of reflections against the first and second mirror members. An image measuring device, characterized in that in claim 14, the first side view image is an image that is flipped left and right with respect to the front view image and the second side view image based on the arrangement positions of the first and second mirror members. In the 14th paragraph, the image analysis unit,
An image measuring device characterized in that it determines viewing angle characteristics corresponding to the first and second side view images by comparing the image characteristics of the first target point set in the frontal view image, the image characteristics of the second target point set in the first side view image, and the image characteristics of the third target point set in the second side view image, respectively. In the 13th paragraph, the at least one mirror member,
An image measuring device further comprising a curved mirror member that reflects light emitted vertically from the display surface to the image acquisition unit. In the 17th paragraph, the image acquisition unit,
An image measuring device characterized by generating a first front view image of the entire display surface that is not reflected by the first and second mirror members and the curved mirror member, a side view image of the entire display surface obtained by reflection on one of the first and second mirror members, and a second front view image obtained by reflection on the curved mirror member. In the 18th paragraph, the image analysis unit,
An image measuring device characterized in that it determines viewing angle characteristics by comparing image characteristics of the first frontal view image with image characteristics of the second frontal view image. In the first paragraph,
An image measuring device further comprising an image generating unit that generates a test image of a preset gradation and supplies the same to the display panel.

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