JP2006125955A - Illumination light quantity control method, inspection method, illumination light quantity controller, and inspection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method, a system, etc. having high defect detection capability wherein the light quantity of a light source is controlled, and effects causing noises are previously removed especially in defect detection inspection. <P>SOLUTION: A panel 3 for light quantity control is provided on an optical path of light emitted from the light source 1A for inspection and comprises a plurality of elements for correcting the light at respectively disposed positions based on a control signal from a panel controller 8. The panel 3 is caused to display an image plane wherein the transmission factor of a selected element is set to be an arbitrary not-minimum transmission factor while the transmission factors of the other elements are minimized. Based on picture image data taken by a camera 6, a picture image processing means 7A detects the highest luminance value in the image plane, compares the luminance value with a reference value or a reference range, determines whether a decided luminance value is the reference value or within the reference range, and decides the transmission factor of the selected element so that it is equal to or less than the reference value or within the reference range based on the determination. This is performed for each of the elements. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an illumination light amount adjustment method, an inspection method using light adjusted and determined by the method, an illumination light amount adjustment device, and an inspection system. In particular, in a system for inspecting, for example, a light-transmissive display panel, a method, apparatus, and system for adjusting and determining the amount of illumination light to eliminate the influence of illumination unevenness and the like that cause a reduction in defect detection capability It is about.

  When detecting a defect or the like to be inspected, it is desirable that the inspection can be performed so that only the defect or the like is detected. For example, when inspecting a light-transmissive display panel (display body; hereinafter referred to as a display panel), the amount of light incident on the display panel has a desired pattern distribution (for example, uniformly on the entire display surface of the panel). Distributed). However, when a lamp such as a point light source that can be regarded as emitting light from one point is used as a light source, the center tends to be brighter and darker toward the outside (for example, the same is true through a condensing lens). ).

  Here, the light transmission type liquid crystal panel utilizes the fact that the light transmittance can be controlled for each component (element, pixel; hereinafter simply referred to as an element), and the light transmitted by the light source is incident on the light transmission type liquid crystal panel. There has been disclosed an illumination control device that corrects illumination unevenness applied to an IC or the like to be inspected by controlling a light shielding rate (see, for example, Patent Document 1). An apparatus using a panel (so-called DMD (registered trademark)) having a light reflection type reflection control element instead of the light transmission type liquid crystal panel is also disclosed (for example, see Patent Document 2).

Japanese Patent Laid-Open No. 11-53923 JP 2001-235686 A

  However, the above-described apparatus is for correcting the incident light to be reflected by the inspection object and directly imaged or visually observed by the imaging apparatus. On the other hand, in the defect detection inspection of the display panel, not only the display panel is directly imaged, but also the image of the display panel enlarged and projected on the screen is imaged by the imaging means, and the image data on the screen is processed. In addition, a method of performing defect detection is also performed (a defect detection inspection by visual inspection by an inspector can also be performed). As described above, when the inspection is performed by indirectly imaging the inspection target via the screen projected on the screen, not only the illumination unevenness due to the light source (the influence of the means provided in the front stage of the display panel) but also the projection lens. Factors such as optical loss, aberration (light wraparound), screen tilt, and the like provided at the rear stage of the display panel increase factors that reduce the detection capability until the image is picked up by the image pickup means. Therefore, it is necessary to finally correct after considering these factors. In addition, since it is difficult to make a one-to-one correspondence between the light receiving element of the imaging unit and the pixels of the display panel projected on the screen, the reliability is reduced even if only the illumination unevenness is corrected. End up.

  Therefore, the amount of light from the light source can be adjusted, especially in display panel defect detection inspection, eliminating the effects of lighting, projection lenses, screens, etc. that would cause noise in defect detection in advance, and higher defect detection capability. It is an object of the present invention to provide a method, a system, and the like.

The method for adjusting the amount of illumination light according to the present invention is for adjusting the amount of light having a plurality of elements that are provided on an optical path of light emitted from a light source and adjust the amount of light by transmission or reflection of light from the light source at the respective positions. The panel is set to an arbitrary transmittance or reflectance that is not the minimum for the selected element, and the transmittance or reflectance of elements other than the selected element is minimized to transmit or reflect the light from the light source, thereby adjusting the light amount. The step of performing display based on light transmitted or reflected by each element of the panel, the step of imaging the screen obtained based on the display, and the image data of the screen obtained by imaging of the imaging unit is the most. The step of detecting a high luminance value and the detected luminance value are compared with a predetermined reference value or reference range to determine whether the detected luminance value is within the reference value or reference range. A step, based on the determination, so that the reference value or reference range, and a step of determining the transmittance or reflectance in a selected element, repeating the steps of by changing the element to be selected.
According to the present invention, it is determined whether or not each element (element) is within the reference value or the reference range, and the light from the light source is adjusted by the light amount adjustment panel adjusted for each element. Irradiation with a desired light amount distribution can be performed. As a result, for example, the inspection object can be irradiated with light with a uniform distribution without uneven illumination in inspection, and the accuracy of inspection such as defect detection can be improved. Further, even when the imaging unit cannot face the imaging target (has an angle), the image data including the influence is processed to adjust the transmittance or reflectance of each element. The influence of the imaging position of the imaging means can be removed.

In the illumination light quantity adjustment method according to the present invention, the data of the position where the highest luminance value is detected is stored in the storage means in association with the data relating to the selected element.
According to the present invention, by associating the position where the highest luminance value is detected with the selected element, for example, the position (coordinate) of the light receiving element of the imaging means and the position (coordinate) of the element of the light amount adjustment panel The correspondence can be grasped.

The illumination light amount adjustment method according to the present invention transmits or reflects light from a light source with a predetermined transmittance or reflectance to each element, and converts it into light by transmission or reflection of each element of the light amount adjustment panel. A step of performing the display based on the image, a step of the image pickup means picking up a screen obtained based on the display by the light amount adjustment panel, and transmitting or reflecting light from the light source at the transmittance or reflectance determined by each element. Determining whether the luminance value of the position corresponding to the data of each position is within the reference value or reference range based on the image data of the screen based on the light, and the luminance value of each position based on the determination The method further includes the step of determining again the transmittance or reflectance of the element corresponding to the element data associated with the data of each position so that is within the reference value or the reference range.
According to the present invention, after determining the transmittance or reflectance for each element, the transmittance or reflectance is adjusted again based on image data obtained by performing display with the determined transmittance or reflectance. Thus, for example, in the case of enlarged projection, the light from the element spreads and superimposes with the light from other elements to increase the brightness, or the brightness between the light at the edge of the screen with little overlap. Even when a difference occurs (for example, projection unevenness), the adjustment can be performed, and a desired light amount distribution can be obtained.

In the illumination light quantity adjustment method according to the present invention, the imaging means images a screen that is enlarged and projected on a screen via a projection lens.
According to the present invention, each element is adjusted based on a screen displayed by the imaging means enlarged and projected on the screen via the projection lens. In addition, the influence of the projection lens and the screen can be removed and adjusted.

In the illumination light quantity adjustment method according to the present invention, the light source, the light quantity adjustment panel, the projection lens, and the screen are arranged on the same optical axis.
According to the present invention, by arranging the light source, the light amount adjustment panel, the projection lens, and the screen on the same optical axis, the adjustment by the light amount adjustment panel particularly when trying to perform a uniform light amount distribution without uneven illumination. It becomes easy to do.

The inspection method according to the present invention irradiates the inspection target with light whose light amount is adjusted by controlling each element of the light amount adjustment panel with the determined transmittance or reflectance according to the illumination light amount adjustment method described above. It is to be inspected.
According to the present invention, since the inspection object is irradiated with light by the above-described illumination light amount adjustment method, inspection with a desired light amount distribution can be performed. This is particularly convenient when it is desired to perform a uniform light amount distribution with no illumination unevenness on the inspection object.

In addition, the illumination light amount adjusting method according to the present invention is configured such that polarized light that matches the polarization element of the inspection target is output from the light amount adjusting panel.
According to the present invention, for example, in an inspection object such as a liquid crystal panel, it is possible to cope with an inspection when a polarizing element (a polarizing plate, a polarizing filter, a polarizing film, etc.) is attached to the inspection object. .

Further, the inspection method according to the present invention is intended to inspect a transmissive display panel.
According to the present invention, it is possible to remove the influence of illumination unevenness etc. with respect to the illumination transmitted through the transmissive display panel, so that it is particularly effective for the inspection of the transmissive display panel.

The illumination light amount adjusting apparatus according to the present invention includes a storage unit that stores data of a predetermined reference value or reference range, and a plurality of elements that adjust the light amount by transmitting or reflecting light from the light source. Light that is transmitted or reflected from the light source with the light transmittance adjustment panel having an arbitrary non-minimum transmittance or reflectance for the selected element and the transmittance or reflectance of elements other than the selected element being minimized. A luminance determination unit that detects the highest luminance value from the luminance value data included in the image data obtained by imaging by the imaging unit, and a reference value or reference stored in the storage unit A comparison judgment unit that compares the range with the detected luminance value and determines whether the detected luminance value is within the reference value or the reference range, and within the reference value or the reference range based on the judgment of the comparison judgment unit Na And an image processing means for determining the transmittance or reflectance of each element by changing the element to be selected and performing processing by changing the element to be selected. It is a thing.
According to the present invention, the image processing means determines whether each element of the light amount adjustment panel is within the reference value or the reference range, and performs a process of adjusting the element for each element, thereby adjusting the light from the light source. Since the illumination light amount adjusting device to be adjusted is realized, irradiation with a desired light amount distribution can be performed. For example, since the inspection object can be irradiated with light with a uniform distribution without illumination unevenness in inspection, the accuracy of inspection such as defect detection can be improved. Further, even when the imaging unit cannot directly face the imaging target, the image data including the influence is processed and the transmittance or reflectance of each element is adjusted. The influence of the position can be removed.

Further, in the illumination light amount adjusting device according to the present invention, each time the element is changed, the luminance determining unit stores the data of the position where the highest luminance value is detected based on the image data in association with the data regarding the selected element. Each of the information stored in the storage unit is stored in the storage unit based on the image data of the screen based on the light transmitted or reflected from the light source with the transmittance or reflectance determined by each element. It is determined whether the luminance value at the position corresponding to the position data is within the reference value or the reference range, and the adjustment unit determines whether the luminance value at each position is within the reference value or the reference range based on the determination by the comparison determination unit. Then, the transmittance or reflectance of the element corresponding to the element data associated with the data at each position is determined again.
According to the present invention, after determining the transmittance or reflectance for each element, the ratio is adjusted again based on the screen obtained by controlling the element at the determined ratio, thereby spreading the light from the element. When the brightness is increased by superimposing light from other elements and there is a difference in brightness with the light at the edge of the screen where the amount of superimposition is small, the adjustment can be made and the desired light distribution Can be obtained.

Further, the inspection system according to the present invention is provided on a light source that emits light for irradiating the inspection target and an optical path of the light emitted from the light source, and based on the control signal, from the light source at each disposed position. A light amount adjustment panel having a plurality of elements that control the amount of light by transmitting or reflecting light, and a light amount adjustment control signal for controlling each element based on the transmittance or reflectance determined by the illumination light amount adjustment device described above Panel control means for transmitting to the control panel, imaging means for imaging the screen displayed by irradiating the light from the light adjustment panel to the inspection object, and transmitting the video signal including the image data of the screen, and the video signal The image processing apparatus includes at least an inspection processing device that performs processing based on the included image data and inspects an inspection target.
ADVANTAGE OF THE INVENTION According to this invention, the light of arbitrary light quantity distribution can be irradiated to test | inspection object by adjusting the light from a light source with each element of an illumination light quantity adjustment apparatus. It is possible to obtain a system that is particularly convenient when the illumination unevenness is eliminated and the amount of light is to be distributed uniformly.

The inspection system according to the present invention further includes a screen and a projection lens for enlarging and projecting the screen onto the screen.
According to the present invention, even if a projection lens and a screen are arranged at a later stage than the inspection target, it is possible to perform an inspection with these effects removed.

In the inspection system according to the present invention, an active matrix driving liquid crystal panel is used as a light amount adjustment panel.
According to the present invention, since the light quantity adjustment panel is composed of an active matrix driving liquid crystal panel and the light is adjusted by each element, the inspection object can be irradiated with a desired light quantity distribution during the inspection. it can.

In the inspection system according to the present invention, a panel that constitutes an element by a reflection control element is a light quantity adjustment panel.
According to the present invention, since the panel constituting the element by the reflection control element is the light quantity adjusting panel, the influence of unevenness other than the inspection target can be removed. Further, it is possible to reduce the loss due to the light amount adjustment panel and irradiate the inspection object with light.

Further, the inspection system according to the present invention is intended to inspect a transmissive display panel.
According to the present invention, light from which the influence of illumination unevenness and the like is removed can be used as the light for transmitting the transmissive display panel, and the inspection accuracy of the transmissive display panel can be increased.

Embodiment 1 FIG.
FIG. 1 is a diagram showing an inspection system for a light transmission type display panel according to a first embodiment of the present invention. In FIG. 1, the light emitted from the illumination device 1 is converted into parallel light by the condenser lens 2. Here, although the parallel light is obtained by condensing the light emitted from the illuminating device 1 with the condensing lens 2, it does not need to be limited to this configuration. Hereinafter, a device in which the illumination device 1 and the condenser lens 2 are combined is referred to as an inspection light source 1A.

  The light amount adjustment panel 3 is composed of, for example, an active matrix driving TFT liquid crystal panel. The elements (pixels) arranged on the panel plane can emit light by changing the light transmittance for each element and adjusting the amount of transmitted light. The light emitted from each element is displayed as a screen as a whole. The panel control device 8 controls the drive (transmittance) of each element. In the present embodiment, it is assumed that the elements are arranged in a matrix on the panel plane, and the position of each element can be represented by a two-dimensional coordinate value (hereinafter referred to as a coordinate value in the light amount adjustment panel 3). Here, in practice, it is almost impossible to set the light transmittance of each element to 0% and 100%. However, in this embodiment, hereinafter, light (light flux) incident on the element and emitted from the element are emitted. The maximum transmittance (percentage of the maximum ratio) is 100% and the minimum transmittance (percentage of the minimum ratio) is 0% with respect to the ratio (percentage of transmission) with the light (luminous flux) explain. In the present embodiment, the term “transmittance” will be used to explain. However, from the viewpoint that the light amount adjustment panel 3 limits the light from the inspection light source 1A, the limiting rate with respect to the above-described transmittance. Can also be considered. In this case, the maximum transmittance (for example, 100%) means that the limiting rate is minimum (for example, 0%), and the minimum transmittance (for example, 0%) means that the limiting rate is maximum (for example, 100%).

  The projection lens 4 is a lens for enlarging and projecting the display image of the inspection object panel 10 on the screen 5. The projection lens 4 is arranged at the rear stage of the inspection object panel 10 when viewed from the traveling direction of the light from the inspection light source 1A. Here, in this embodiment, it is assumed that the illumination device 1, the condenser lens 2, the light amount adjustment panel 3, the projection lens 4, and the screen 5 are on the same optical axis. However, since the direction can be changed using a mirror or the like (not shown), it is not necessarily arranged in series.

  The camera 6 serving as an image pickup unit is a device for picking up an image projected on the screen 5 and includes, for example, a CCD camera having a plurality of light receiving elements such as a CCD. Each light receiving element converts the amount of received light into an electrical signal, for example, and transmits it as a video signal. Here, the light receiving elements are also arranged in a matrix, and the position of each light receiving element can be represented by a two-dimensional coordinate value (hereinafter referred to as a coordinate value in the camera 6).

  The image processing apparatus 7 that performs processing for adjusting the amount of light performs processing described later on the basis of captured image data (data on the amount of light received by each light receiving element) included in the video signal transmitted from the camera 6. The transmittance of each element of the light amount adjustment panel 3 at the time of panel inspection is determined. Further, at the time of panel inspection, image data obtained by imaging a screen on which an inspection target is displayed is processed, and an inspection processing apparatus for detecting a defect in the inspection target panel 10 is obtained. The image processing apparatus 7 includes an image processing unit 7A and a data storage unit 7B. The image processing unit 7A is further composed of a luminance / position determination unit 7A-1, a comparison determination unit 7A-2, and a transmittance adjustment unit 7A-3. Composed. The luminance / position determining unit 7A-1 determines the highest luminance value and its position in the image captured by the camera 6 based on the image data (data on the amount of light received by each light receiving element) in the video signal. The comparison determination unit 7A-2 compares the maximum luminance value determined by the luminance / position determination unit 7A-1 with a predetermined luminance threshold, and the maximum luminance value is equal to or less than a threshold value that is a reference value or a reference range. It is determined whether it is within the error range. Based on the determination of the comparison determination unit 7A-2, the transmittance adjustment unit 7A-3 determines the adjustment transmittance to reduce the luminance value of the portion having a high luminance value, and adjusts the adjustment to the panel control device 8. Drive control is performed with the transmittance adjusted for the target element. Note that the luminance here is more strictly the amount of light received by each light receiving element when the camera 6 captures light transmitted through each element projected onto the screen 5 via the projection lens 4. The maximum value of luminance in the element is the amount of light received by the light receiving element that has received the largest amount of light received.

  The data storage means 7B is means for temporarily or long-term storing data for the image processing means 7A to determine the transmittance. In the data storage unit 7B, for example, the transmittance, the coordinate value in the light amount adjustment panel 3, and the coordinate value in the camera 6 are stored as data in association with each element of the light amount adjustment panel 3. In addition, since the comparison / determination unit 7A-2 performs comparison, data of a predetermined luminance threshold value or error range is stored. Further, in order for the transmittance adjusting unit 7A-3 to determine the adjustment transmittance, the difference between the predetermined luminance threshold or the maximum value of the luminance with an error range and the value of the adjusted transmittance are associated with each other. May be stored as data. Further, for example, a program for causing the image processing means 7A to execute a processing procedure to be described later may be stored.

  The panel control device 8 controls the drive (transmittance) of each element with the transmittance of each element determined by the image processing device 7 based on the instruction signal from the image processing device 7. Specifically, the voltage applied to each element is controlled in accordance with the transmittance. Here, in the present embodiment, the panel control device 8 controls the driving of the light amount adjustment panel 3 based on the instruction signal from the image processing device 7. However, for example, if a storage means for storing the transmittance of each element determined by the image processing device 7 and the coordinate value in the light amount adjustment panel 3 is provided, the panel control device 8 can be used after the transmittance is determined. The drive control of the light amount adjustment panel 3 can be independently performed.

  The inspection object panel 10 is a light transmission type panel such as a liquid crystal panel (display body). It is connected to a pattern generator (not shown), and performs a predetermined display for performing inspection by controlling the light transmittance of each pixel. This display is magnified by the projection lens 4 and projected onto the screen 5. Here, since the present embodiment relates to a process for eliminating illumination unevenness in the previous stage of inspection, the inspection object panel 10 is not used. Note that the processing of the present embodiment is not necessarily processing that must be performed before each inspection, but can be performed arbitrarily, such as when the inspection light source 1 is replaced or distribution settings are changed. Can be done if.

  FIG. 2 is a diagram showing a processing procedure for determining the transmittance of each element at the time of inspection with the image processing apparatus 7 as the center. In the present embodiment, a process performed to eliminate illumination unevenness, which is performed before the inspection is performed by projecting the image of the inspection target panel 10 onto the screen 5, will be described. Therefore, in this embodiment, the transmittance of each element of the light amount adjustment panel 3 is determined so that the luminance of the entire projected and displayed screen is as uniform as possible.

  First, an error range allowable as the maximum luminance value or the maximum luminance value in the element is set in advance as a threshold value or range and stored in the data storage unit 7B (S1). Here, in order to make the luminance of the entire screen uniform in order to eliminate illumination unevenness, the same threshold value or error range is set for all elements. In addition, a threshold value in consideration of the error may be set in advance.

  When the maximum luminance value or the error range is set, the image processing apparatus 7 selects the presence / absence of transmittance adjustment and an element for which the transmittance is determined (hereinafter referred to as an adjustment element) (S2). Here, although it is possible to select any element of the light amount adjustment panel 3 to be a determination target in any order, in the present embodiment, it is determined whether or not the transmittance is adjusted for all elements, In some cases, the transmittance is adjusted. Further, as viewed from the inspection light source 1A, the transmittance is determined by determining whether or not the transmittance is adjusted in order from the upper left element toward the right. It is assumed that the process moves to the left element and proceeds to the right. Here, when an error range is set and a determination is made based on the error range, considering that the outside tends to be dark, starting from the element on the outside (end), such as the upper left, If only the maximum value of the luminance below the error range is obtained, it is determined that the amount of light from the inspection light source 1A is small, and the inspection light source 1A can be adjusted immediately.

  Next, the panel control device 8 sets the transmittance to 100% for the selected adjustment element based on the instruction signal from the image processing device 7 and sets the transmittance to 0% for the other elements. Each element of the adjustment panel 3 is driven and controlled (S3). Light transmitted based on this drive control is projected and displayed on the screen 5 via the projection lens 4.

  The display of the screen projected on the screen 5 through the projection lens 4 is imaged by the camera 6, converted into a video signal including image data, and transmitted (S4). In the image processing device 7, the luminance / position determination unit 7 </ b> A- 1 performs sort processing on the luminance value data based on the captured image data included in the video signal, A process of searching for the maximum luminance value and the position of the luminance is performed. Then, the position where the maximum luminance value is obtained is stored in the data storage means 7B as coordinate value data in the camera 6. At this time, since the selected adjustment element is known, the coordinate value data in the light amount adjustment panel 3 and the coordinate value data in the camera 6 are stored in association with each other. Further, the comparison / determination unit 7A-2 determines whether or not the searched luminance maximum value is within the set threshold value stored in the data storage unit 7B or within the error range (S5). If it is below the threshold value or within the error range, the transmittance data at that time is stored in the data storage means 7B in association with the coordinate value data in the light amount adjustment panel 3 and the coordinate value data in the camera 6.

  On the other hand, if the comparison determination unit 7A-2 determines that the searched luminance maximum value is higher than the threshold value or the error range, the transmittance adjustment unit 7A-3 may reduce the transmittance with respect to the adjustment element. To determine the transmittance of the adjustment. Then, the panel control device 8 is driven and controlled with the adjusted transmittance (S6). As a method for determining the transmittance for adjustment, for example, the relationship between the luminance difference (difference between the searched luminance maximum value and the threshold value or error range) and the transmittance is stored in the data storage unit 7B in a table format or the like in advance. In addition, there is a method of determining the corresponding transmittance or the decrease in the transmittance based on the luminance difference. It is also possible to prepare a calculation formula using the brightness difference as a variable in advance and substitute the calculated brightness difference value into the variable to determine the transmittance or the decrease in transmittance.

  The adjustment element is controlled by the determined adjustment transmittance, and for the video signal obtained by projecting on the screen 5, the searched luminance maximum value is equal to or less than the set threshold value stored in the data storage means 7B or the error range. (S4, S5), and the process is repeated until the luminance by the adjustment element is equal to or less than a set threshold value or within an error range.

  In the image processing device 7, it is determined whether or not adjustment has been made for all elements, it is determined whether or not the transmittance determination has been completed (S7), and if it is determined that the adjustment has not been completed, the next adjustment element is selected. The processes of S2 to S7 described above are performed. When the transmittance is determined for all the elements of the light amount adjustment panel 3, the process is terminated.

  When inspecting the inspection object panel 10, the panel control device 8 controls each element of the light amount adjustment panel 3 so that the light of the inspection light source is transmitted with the transmittance determined by the image processing device 7 based on the instruction signal. To do.

  As described above, according to the first embodiment, for each element of the light amount adjustment panel 3, the image processing means 7A determines whether it is below the threshold value or within the error range, and it is determined for all the elements. Since adjustment is performed and the panel control device 8 controls each element with the transmittance adjusted when the inspection target panel 10 is inspected, it is possible to perform irradiation with a desired light amount distribution. In particular, in the case of the present embodiment, a uniform light amount distribution without illumination unevenness can be easily obtained, and the inspection object panel 10 can be irradiated. In the case of projection inspection, it is difficult to face the camera 6 directly to the inspection target panel. However, the image data to be processed when adjusting each element is affected by the imaging position, angle, and the like of the camera 6. Since the adjustment of the element is included, the influence can be removed. In the present embodiment, the projection lens 4 is used for the enlarged projection, but the influence caused by the difference in the thickness of the lens can be eliminated. Further, the coordinates of the highest luminance and the coordinates of the element are associated with each other and stored in the data storage unit 7B, whereby the position (coordinate) in the camera 6 and the position (coordinate) of the element of the light amount adjustment panel 3 are made to correspond to each other. be able to.

Embodiment 2. FIG.
In the first embodiment described above, the transmittance of the elements other than the adjustment element is set to 0%, and the luminance is determined by determining the luminance of the adjustment element. However, in actual inspection, all the elements transmit light from the inspection light source 1A with the determined transmittance. Therefore, since the transmittance of elements around a certain element is not 0%, the luminance at the position of a certain element is affected by the light transmitted through the peripheral element. As a result, the brightness tends to be higher as a whole than when only a certain element transmits light alone. However, the number of elements that affect the brightness at each position differs between the central part and the outer part, and there is also an influence of the aberration of the projection lens 4 (enlargement of the projection range of transmitted light by enlarged projection). Even if the variation in transmitted light is reduced, there is a high possibility that a luminance difference will occur between the central portion and the outer portion. In the present embodiment, in consideration of such influences, the transmittance of each adjusted element is further adjusted so that the final distribution can be obtained in order to make the distribution of illumination uniform at the time of inspection. To decide.

  FIG. 3 is a diagram showing a processing procedure for determining the transmittance of the element according to the second embodiment of the present invention. Although the processing procedure in the image processing apparatus 7 is different from that in the first embodiment, the configuration of the system is the same as that in FIG. In FIG. 3, S1 to S7 for performing the process of determining the transmittance of the adjustment element with the transmittance other than the adjustment element set to 0% will be described because the same process as described in the first embodiment is performed. Omitted. When the processing of S1 to S7 is completed, lens aberration / projection unevenness correction (transmittance adjustment and final determination) processing is performed (S8). In this example, processing for correcting lens aberration / projection unevenness will be described. However, this processing is not only for lens aberration / projection unevenness, but when the light diverges due to other causes, etc. It can also be applied to.

  FIG. 4 is a diagram illustrating a processing procedure of lens aberration / projection unevenness correction processing. The panel control device 8 controls each element of the light amount adjustment panel 3 to have the determined transmittance based on the instruction signal of the image processing device 7 (S11). The screen is displayed based on the determined transmittance.

  The image processing apparatus 7 selects an adjustment element (S12). Also in this selection, in this embodiment, selection is performed in order from the upper left element in the same manner as S2.

  The display projected onto the screen 5 via the projection lens 4 is imaged by the camera 6 and converted into a video signal (S13). In S5, the brightness / position determination unit 7A-1 searches for the maximum brightness based on the video signal, but the image obtained here is a projection of the light transmitted by all the elements with the determined transmittance. Therefore, it cannot be searched by the same method as S5. Therefore, the luminance / position determination unit 7A-1 searches the coordinate value in the camera 6 corresponding to the coordinate value in the light amount adjustment panel 3 of the selected adjustment element from the data stored in the data storage unit 7B. And the luminance value of the coordinate value in the camera 6 is extracted as data.

  The comparison determination unit 7A-2 determines whether the extracted luminance value is equal to or less than the set threshold value stored in the data storage unit 7B or within an error range (S14). If it is less than the threshold value or within the error range, the transmittance data stored in the data storage means 7B is not changed.

  On the other hand, if the comparison determination unit 7A-2 determines that the searched luminance maximum value is higher than the threshold value or the error range, the transmittance adjustment unit 7A-3 adjusts the adjustment transmittance for the adjustment element as in S6. To decide. Then, the adjustment element is controlled by the determined adjustment transmittance (S15), and the searched luminance maximum value is stored in the data storage means 7B for the video signal obtained by projection on the screen 5. It is determined whether it is below the threshold value or within the error range (S13, S14), and the process is repeated until the brightness by the adjusting element is below the set threshold value or within the error range.

  In the image processing apparatus 7, it is determined whether or not adjustment has been performed for all elements, it is determined whether or not the transmittance determination is completed (S16), and if it is determined that the adjustment has not been completed, the next adjustment element is selected. The processes of S12 to S15 described above are performed.

  Although the above processing may be performed to end the processing, in the present embodiment, the lens aberration / projection unevenness correction processing is repeated a plurality of times (S9). This does not only affect the brightness at the position where light emitted from the element is projected, but also the brightness at the position where light emitted from the surrounding elements is projected. May affect. This is because it affects the elements whose transmittance has already been determined, and there is a possibility that the luminance is shifted (increased). Therefore, by repeating the above process, the adjustment accuracy can be increased by converging the luminance shift. Usually, the accuracy increases by repeating 2 to 4 times.

  As described above, according to the second embodiment, after determining the transmittance for all the elements, the image processing means 7A re-appears based on the screen obtained by controlling all the elements with the determined transmittance. By adjusting the transmittance, for example, the light emitted from the element due to the aberration of the projection lens is projected onto the screen in a broadened manner, and the brightness is increased by superimposing the light from other elements, resulting in a screen with little overlap. Even when a difference in brightness occurs between the light at the end (projection unevenness occurs), the adjustment can be performed, and a desired light amount distribution (particularly, a uniform light amount distribution) can be obtained.

Embodiment 3 FIG.
In the above-described embodiment, in order to eliminate illumination unevenness and the like, the threshold value or error range is set so as to have a uniform distribution, and the transmittance is determined for all elements of the light amount adjustment panel 3. In the present invention, the present invention is not limited to this. For each element or group of elements, the amount of transmitted light is controlled by setting a threshold value or error range for each group. You may make it determine and control the transmittance | permeability of each element so that it may become distribution. At this time, it may be performed for any element of the light amount adjustment panel 3. Further, for example, the distribution can be changed by intentionally shifting the optical axis without facing the incident direction of light.

  Further, in the above-described embodiment, it is determined whether the luminance value when light is transmitted with the maximum transmittance for the selected element is equal to or less than a threshold value or within an error range, and the transmittance for adjustment is determined. However, the present invention is not limited to this. For example, if the selected element and its position in the screen can be specified, it is not necessary to start from the case where the transmittance is maximum. For example, the transmittance may be started from 80%, or the transmittance may be initially lowered and adjusted in the increasing direction. Here, in the above-described embodiment, the comparison determination unit 7A-2 determines whether or not it is equal to or less than the threshold value. However, if the transmittance is not maximum, it may be equal to or less than the threshold value from the beginning. In this case, for example, whether or not the threshold value is a reference value is used as a reference for comparison determination, and the adjustment transmittance is determined so as to become the threshold value.

Embodiment 4 FIG.
Although not particularly shown in the above-described embodiment, for example, a polarizing plate (polarizing filter) may be attached to the inspection target panel 10 in a liquid crystal display panel. On the other hand, a liquid crystal display panel provided with a polarizing plate polarizing filter can also be used for the light amount adjusting panel 3, but in this case, the polarization direction (light) of the polarizing plate attached to the transmission side of the light amount adjusting panel 3 The polarization direction of the polarizing plate attached to the incident side of the light quantity adjustment panel 3 is set to 90. Deg shift).

Embodiment 5. FIG.
In the above-described embodiment, for example, a case where inspection is performed using a display panel that is a component of a projector as an inspection target has been described. However, for example, inspection of a projector that is a combined product of a light source and a liquid crystal display panel, and projection of a screen are performed. The method of the present invention can also be applied to the adjustment. The method of the present invention is also particularly suitable for an inspection performed by projecting onto a screen. However, the method of the present invention can also be applied to an inspection performed by directly imaging a light transmission type display device or the like. . It can also be applied to uses other than inspection.

Embodiment 6 FIG.
In the above-described embodiment, the light intensity adjustment panel 3 that is a light transmission type panel is used to perform the above-described processing to determine the transmittance of each element and to correct illumination unevenness and the like. The present invention is not limited to this. Instead of the light amount adjustment panel 3, a panel having the above-described light reflection type reflection control element is used, and the reflectance of each reflection control element (mirror element) is adjusted. By determining and controlling, illumination unevenness and the like may be corrected. In this case, when the inspection target is a display panel as described above, the light reflected using a prism or the like is irradiated onto the display panel.

The figure showing the inspection system of the light transmission type display panel concerning a 1st embodiment. The figure which showed the process sequence which determines the transmittance | permeability of each element at the time of a test | inspection. The figure of the process sequence which determines the transmittance | permeability of the element which concerns on 2nd Embodiment. The figure which shows the process sequence of a lens aberration and projection nonuniformity correction process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Illumination device, 2 Condensing lens, 1A Inspection light source, 3 Light quantity adjustment panel, 4 Projection lens, 5 Screen, 6 Camera, 7 Image processing apparatus, 7A Image processing means, 7A-1 Luminance and position judgment part, 7A -2 Comparison judgment unit, 7A-3 Transmittance adjustment unit, 7B Data storage means, 8 Panel control device

Claims (15)

For the light quantity adjustment panel provided on the optical path of the light emitted from the light source and having a plurality of elements for adjusting the light quantity by transmitting or reflecting the light from the light source at the respective positions, the selected elements are Arbitrary transmittance or reflectance other than the minimum is selected, and the transmittance or reflectance of the elements other than the selected element is minimized so that the light from the light source is transmitted or reflected, and transmitted through each element of the light amount adjustment panel. Or a step of performing display based on light by reflection;
A step in which an imaging unit images a screen obtained based on the display;
Detecting the highest luminance value from the image data of the screen imaged by the imaging means;
Comparing the detected brightness value with a predetermined reference value or reference range and determining whether the detected brightness value is within the reference value or the reference range;
And determining the transmittance or the reflectance of the selected element so as to be within the reference value or the reference range based on the determination,
A method for adjusting the amount of illumination light, wherein the element to be selected is changed and the above steps are repeated.   2. The illumination light quantity adjusting method according to claim 1, wherein the storage unit stores the data of the position where the highest luminance value is detected in association with the data relating to the selected element. A step of causing each element to transmit or reflect light from the light source at the transmittance or reflectance determined in advance and to perform display based on light transmitted or reflected by each element of the light amount adjustment panel; ,
A step in which an imaging unit images a screen obtained based on display by the light amount adjustment panel;
Based on the image data of the screen based on the light transmitted or reflected by the light with the transmittance or the reflectance determined by each element, the luminance value at the position corresponding to the data at each position is the reference. Determining whether the value is within the reference range;
Based on the determination, the transmittance or reflectance of the element corresponding to the element data associated with the data of each position is set so that the luminance value of each position falls within the reference value or the reference range. The illumination light quantity adjustment method according to claim 2, further comprising a step of determining again.   The illumination light quantity adjustment method according to claim 1, wherein the imaging unit images the screen enlarged and projected on a screen through a projection lens.   5. The illumination light quantity adjustment method according to claim 4, wherein the light source, the light quantity adjustment panel, the projection lens, and the screen are arranged on the same optical axis.   Inspection by irradiating the inspection target with light whose light amount is adjusted by controlling each element of the light amount adjustment panel with the determined transmittance or reflectance according to the illumination light amount adjustment method according to claim 1. An inspection method characterized by:   The inspection method according to claim 6, wherein polarized light that matches a polarization element included in the inspection target is output from the light amount adjustment panel.   The inspection method according to claim 6 or 7, wherein a transmissive display panel is the inspection object. Storage means for storing data of a predetermined reference value or reference range;
For the light amount adjustment panel having a plurality of elements that adjust the light amount by transmitting or reflecting light from the light source, the selected element has an arbitrary transmittance or reflectance that is not minimum, and the elements other than the selected element The screen obtained by display with light transmitted or reflected by the light from the light source with the minimum transmittance or reflectance is selected from the luminance value data included in the image data obtained by the imaging means. A luminance determination unit for detecting a high luminance value;
A comparison determination unit that compares the reference value or the reference range stored in the storage unit with the detected luminance value and determines whether the detected luminance value is within the reference value or the reference range; ,
An adjustment unit that determines the transmittance or the reflectance of the selected element so as to be within the reference value or the reference range based on the determination of the comparison determination unit;
An illumination light amount adjusting apparatus comprising: an image processing unit that performs processing by changing the element to be selected and determines the transmittance or the reflectance of each element. Each time the element is changed, the luminance determination unit stores the data of the position where the highest luminance value is detected based on the image data in the storage unit in association with the data regarding the selected element,
Each position stored in the storage unit based on the image data of the screen based on the light transmitted or reflected by the light transmitted from the light source at the transmittance or the reflectance determined by each element. Determining whether or not the luminance value at the position corresponding to the data is within the reference value or the reference range,
Based on the determination of the comparison determination unit, the adjustment unit corresponds to element data associated with the data of each position so that the luminance value of each position falls within the reference value or the reference range. The illumination light quantity adjusting device according to claim 9, wherein the transmittance or the reflectance is determined again. A light source that emits light for irradiating the inspection object;
A light amount adjustment panel provided on an optical path of light emitted from the light source, and having a plurality of elements that control the light amount by transmitting or reflecting the light from the light source at respective positions based on a control signal; ,
Panel control means for transmitting a control signal for controlling each of the elements based on the transmittance or reflectance determined by the illumination light quantity adjusting device according to claim 9 or 10, to the light quantity adjusting panel;
Imaging means for imaging a screen displayed by irradiating the inspection target with light from the light amount adjustment panel, and transmitting a video signal including image data of the screen;
An inspection system comprising at least an inspection processing device that performs processing based on image data included in the video signal and inspects the inspection object. Screen,
The inspection system according to claim 11, further comprising a projection lens for enlarging and projecting the screen onto the screen.   13. The inspection system according to claim 11, wherein an active matrix driving liquid crystal panel is used as the light amount adjustment panel.   The inspection system according to claim 11 or 12, wherein a panel that constitutes the element by a reflection control element is used as the light quantity adjusting panel.   The inspection system according to claim 11, wherein a transmission type display panel is the inspection target.

Images