TW202146854A - Optical machine inspection method - Google Patents

Abstract

An optical machine inspection method is disclosed. The optical machine inspection method includes steps of: (a) designing a gray-scale adjustable uniform light source array to measure the gray-scale brightness variation information provided by the light source; (b) the gray-scale adjustable uniform light source array inputting a test pattern; (c) calculating an actual brightness according to the test pattern; (d)the optical machine under test shooting the test pattern and obtaining a captured brightness after calculation; (e) generating an evaluation of whether the optical machine under test needs to be calibrated according to the difference between the actual brightness and the captured brightness; and (f) automatically calibrating to provide a correct optical machine shooting environment.

Description

Optical machine inspection method

The present invention relates to optical detection technology, in particular to an optical machine inspection method.

Generally speaking, an optical machine usually includes two main components, a lens and a sensor, and its main task is data acquisition. The lens system is used to convert the object space information to the image space plane. This conversion process is easily affected by factors such as vignetting, cosine quadratic distribution, and pixel displacement caused by lens distortion, so the lens needs to be corrected. The sensor is used to convert the optical signal of the image space plane into an electrical signal and then into a digital signal. In this conversion process, factors such as exposure time and moiré need to be considered.

For example, if the exposure time is too short, the signal-to-noise ratio will be too low, resulting in poor quality of optical data, which is likely to cause a decrease in the fineness of compensation; on the contrary, if the exposure time is too long, the parts with high optical brightness are easily saturated, resulting in local compensation. abnormal. As for the moiré, it is related to the sampling frequency. Since the spatial frequency of the panel and the sensor will generate sum frequency and difference frequency, and the sum frequency within the Nyquist frequency is easy to be sampled and observed, resulting in the appearance of moiré at high gray levels. Therefore, the optical factory needs to remove it.

In addition, in the process of data acquisition by the optical machine, the following problems may also be encountered: If the lens factory adds an algorithm to the optical machine, it may cause a sand-like uneven brightness (Mura) phenomenon after compensation, which needs to be corrected. ; If the optical machine is not coaxial with the panel when shooting, the optical data will be skewed and need to be corrected; if the average brightness of the optical data provided by the optical machine does not fall on the Gamma curve, it means that the optical data The information is incorrect, the settings during shooting may be wrong, and need to be corrected.

However, because the traditional optical machine detection equipment often has poor shooting results when shooting periodic objects, but there is no other equipment that can prove that the detection equipment has problems, it is impossible to check, resulting in the optical machine collecting wrong images. The data affects subsequent applications, such as de-uniform brightness (Demura), etc., and needs to be improved urgently.

In view of this, the present invention proposes an optical machine inspection method to effectively solve the above-mentioned problems encountered in the prior art.

A specific embodiment according to the present invention is an optical machine inspection method. In this embodiment, the method includes the following steps: (a) designing a gray-scale tunable uniform light source array to measure the gray-scale brightness change information provided by the light source; (b) inputting a test pattern to the gray-scale tunable uniform light source array; (c) Calculate the actual brightness according to the test pattern; (d) The optical machine to be tested captures the test pattern and obtains the captured brightness after calculation; (e) Generates the optical machine to be tested according to the difference between the actual brightness and the captured brightness evaluation of whether the stage needs to be calibrated; and (f) automatic calibration to provide the correct optical machine shooting environment.

In one embodiment, the light source can be a laser, a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL) or other light sources.

In one embodiment, when the gray-scale adjustable uniform light source array is designed as a transmission type, the gray-scale adjustable uniform light source array includes a first lens, a second lens and a transmission unit, and the light emitted by the light source passes through the first lens in sequence. The lens, the second lens and the penetrating unit are emitted to the optical machine to be tested.

In one embodiment, when the gray-scale adjustable uniform light source array is designed as a vertical reflection type, the gray-scale adjustable uniform light source array includes a first lens, a second lens and a vertical reflection unit, and the light emitted by the light source passes through the first lens in sequence. The lens and the second lens are vertically reflected by the vertical reflection unit to the optical machine to be tested.

In one embodiment, when the gray-scale adjustable uniform light source array is designed as an oblique reflection type, the gray-scale adjustable uniform light source array includes a first lens, a second lens and an oblique reflection unit, and the light emitted by the light source passes through in sequence. The first lens and the second lens are then obliquely reflected by the oblique reflection unit to the optical machine to be measured.

In one embodiment, when the gray-scale adjustable uniform light source array is designed as a homogenizer type, the gray-scale adjustable uniform light source array includes a first lens, a first homogenizer, a second homogenizer, a second lens and Through the penetration unit, the light emitted by the light source passes through the first lens, the first homogenizer, the second homogenizer, the second lens and the penetration unit in sequence and then is emitted to the optical machine to be tested.

In one embodiment, when the gray-scale adjustable uniform light source array is designed as a light guide plate type, the gray-scale adjustable uniform light source array includes a light guide plate, a diffuser and a transparent module, and the light emitted by the light source passes through the light guide plate, diffuses and diffuses in sequence. After the film and the transparent module are shot to the optical machine to be tested.

In one embodiment, when the gray-scale adjustable uniform light source array is designed as a light guide column, the gray-scale adjustable uniform light source array includes a light guide column and a transparent module, and the light emitted by the light source passes through the light guide column and the transparent module in sequence. Shot to the optical machine to be tested.

In one embodiment, the step (c) is to convert the test pattern through an optical transfer function to generate the actual luminance.

In one embodiment, the step (e) includes the following steps: (e1) calculating a difference pattern between the actual luminance and the captured luminance; and (e2) analyzing the difference pattern through an algorithm and generating according to the analysis result whether the optical machine to be tested needs Corrected evaluation.

In one embodiment, when the difference pattern has a relatively fine moiré signal, step (e2) generates an evaluation that the setting of the integration range parameter of the optical machine to be tested needs to be corrected.

In one embodiment, when the difference pattern has moiré signals in a wide range, step (e2) generates an evaluation that the setting of the focus parameter of the optical machine to be tested needs to be corrected.

In one embodiment, when local brightness unevenness occurs in the difference pattern, step (e2) generates an evaluation that the setting of the exposure time of the optical machine to be tested needs to be corrected.

In one embodiment, when the difference pattern has large-scale uneven brightness, step (e2) generates an evaluation that the setting of the uniform field of the optical machine to be tested needs to be corrected.

Compared with the prior art, the present invention provides an optical machine inspection method, which can obtain both the actual brightness generated by the conversion of the test pattern through the optical conversion function and the captured brightness obtained after the test pattern is photographed and calculated by the optical machine to be tested. The difference pattern between the two is analyzed through an algorithm to determine whether there is any abnormality in the difference pattern, so as to determine whether the parameter setting of the optical machine to be tested needs to be corrected. Therefore, the optical machine inspection method of the present invention can achieve the specific effect of quickly inspecting the optical machine to be tested, and can correct the parameter setting of the optical machine to be tested according to the inspection result to eliminate abnormality.

The advantages and spirit of the present invention can be further understood from the following detailed description of the invention and the accompanying drawings.

Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Elements/components using the same or similar numbers in the drawings and the embodiments are intended to represent the same or similar parts.

A specific embodiment according to the present invention is an optical machine inspection method. In this embodiment, the optical machine inspection method is used to quickly check whether the optical machine to be tested is abnormal, and the parameter settings of the optical machine to be tested can be corrected according to the inspection result to eliminate the abnormality, but it is not limited thereto.

Please refer to FIG. 1 . FIG. 1 shows a flowchart of the optical machine inspection method in this embodiment. As shown in FIG. 1 , the optical machine inspection method in this embodiment may include the following steps:

Step S10 : designing a gray-scale adjustable uniform light source array to measure the gray-scale brightness change information provided by the light source;

Step S12: inputting a test pattern into a uniform light source array with adjustable gray scale;

Step S14: Calculate the actual brightness according to the test pattern;

Step S16: the optical machine to be tested captures the test pattern and obtains the captured luminance after calculation;

Step S18 : generating an evaluation of whether the optical machine to be tested needs to be calibrated according to the difference between the actual brightness and the captured brightness; and

Step S20: Correction is performed automatically to provide a correct shooting environment of the optical machine.

Please refer to FIG. 2A . FIG. 2A is a schematic diagram corresponding to step S10 in FIG. 1 . As shown in FIG. 2A , in the optical machine inspection method of the present invention, a gray-scale adjustable uniform light source array ULA can be designed to measure the gray-scale luminance change information (optical transfer function) provided by the light source through a computer PC.

Please refer to FIG. 2B . FIG. 2B is a schematic diagram corresponding to steps S12 to S16 in FIG. 1 . As shown in FIG. 2B , in the optical machine inspection method of the present invention, a test pattern TP can be input into the gray-scale adjustable uniform light source array ULA, and the computer PC1 can calculate the actual brightness AB according to the test pattern TP, and the optical machine DUT to be tested can be used to calculate the actual brightness AB. The captured luminance CB is obtained after shooting the test pattern TP and calculating by the computer PC2.

Please refer to FIG. 3 . FIG. 3 is a schematic diagram illustrating that the uniform light source array with adjustable gray scale is designed as a transmission type. As shown in FIG. 3 , when the gray-scale tunable uniform light source array 3 is designed as a penetrating type, the gray-scale tunable uniform light source array 3 includes a first lens LN1, a second lens LN2 and a penetrating unit PT. The light passes through the first lens LN1 , the second lens LN2 and the penetrating unit PT in sequence to be emitted to the optical device DUT to be tested. It should be noted that the penetration unit PT may be a liquid crystal display (Liquid Crystal Display, LCD) or a spatial light modulator (Spatial Light Modulator, SLM), but not limited thereto.

Please refer to FIG. 4 . FIG. 4 is a schematic diagram illustrating that the gray-scale tunable uniform light source array is designed as a vertical reflection type. As shown in FIG. 4 , when the gray-scale adjustable uniform light source array 4 is designed as a vertical reflection type, the gray-scale adjustable uniform light source array 4 includes a first lens LN1, a second lens LN2 and a vertical reflection unit VR. The light passes through the first lens LN1 and the second lens LN2 in sequence and is vertically reflected by the vertical reflection unit VR to the optical machine DUT to be measured. It should be noted that, the vertical reflection unit VR may be a polarization beam splitter (Polarization Beam Splitter, PBS), but not limited thereto.

Please refer to FIG. 5 . FIG. 5 is a schematic diagram illustrating that the gray-scale adjustable uniform light source array 5 is designed as an oblique reflection type. As shown in FIG. 5 , when the gray-scale adjustable uniform light source array 5 is designed as an oblique reflection type, the gray-scale adjustable uniform light source array 5 includes a first lens LN1, a second lens LN2 and an oblique reflection unit DMD, and the light source LS The emitted light passes through the first lens LN1 and the second lens LN2 in sequence, and is then obliquely reflected by the oblique reflection unit DMD to the optical machine to be measured DUT. It should be noted that the oblique reflection unit DMD may be a digital micromirror device (Digital Micromirror Device, DMD), but is not limited thereto.

Please refer to FIG. 6 . FIG. 6 is a schematic diagram illustrating that the uniform light source array with adjustable gray scale is designed as a diffuser type. As shown in FIG. 6 , when the gray-scale adjustable uniform light source array 6 is designed as a light homogenizer type, the gray-scale adjustable uniform light source array 6 includes a first lens LN1, a first light homogenizer H1, and a second light homogenizer H2 , the second lens LN2 and the penetrating unit PT, the light emitted by the light source LS passes through the first lens LN1, the first homogenizer H1, the second homogenizer H2, the second lens LN2 and the penetrating unit PT in sequence and then shoots to The optical machine DUT to be tested. It should be noted that, the first light homogenizer H1 and the second light homogenizer H2 may be formed by a plurality of lenses arranged adjacently, but not limited thereto.

Please refer to FIG. 7 . FIG. 7 is a schematic diagram illustrating that the gray-scale adjustable uniform light source array is designed as a light guide plate type. As shown in FIG. 7 , when the gray-scale adjustable uniform light source array 7 is designed as a light guide plate type, the gray-scale adjustable uniform light source array 7 includes a light guide plate LG, a diffuser DF and a penetrating unit PT. The light emitted by the light source LS depends on After passing through the light guide plate LG, the diffuser DF and the penetrating unit PT in sequence, it is emitted to the optical machine DUT to be tested, but not limited to this. It should be noted that the light source LS can be disposed outside the light incident side of the light guide plate LG, so that the light emitted by the light source LS is incident into the light guide plate LG from the light incident side of the light guide plate LG, and is disposed inside the light guide plate LG through the light source LS. The light concentrating unit condenses the light and emits the light to the diffuser DF located outside the light exit side of the light guide plate LG, and the light exit side and the light entrance side are perpendicular to each other, but not limited thereto.

Please refer to FIG. 8 . FIG. 8 is a schematic diagram illustrating that the uniform light source array with adjustable gray scale is designed as a light guide column. As shown in FIG. 8 , when the gray-scale adjustable uniform light source array 8 is designed as a light guide column, the gray-scale adjustable uniform light source array 8 includes a light guide column LP and a penetrating unit PT, and the light emitted by the light source LS passes through the light guide column in sequence. The LP and the penetrating unit PT are then shot to the optical machine DUT to be tested. It should be noted that the light source LS can be arranged outside the light incident side of the light guide column LP, so that the light emitted by the light source LS is incident from the light incident side of the light guide column LP into the light guide column LP and directed towards the light source located in the light guide column LP. The penetrating unit PT outside the light exit side, and the light exit side and the light entrance side of the light guide column LP are disposed opposite to each other, but not limited thereto.

It should be noted that in practical applications, different design methods can be used to design the gray-scale tunable uniform light source array ULA according to different requirements. The above embodiment only lists the more common design methods, but is not limited thereto.

Please refer to FIG. 9. FIG. 9 shows a flowchart of step S18 in FIG. 1 further including steps S18A-S18B. As shown in FIG. 9, step S18 may include:

Step S18A: Calculate the difference graph between the actual brightness and the captured brightness; and

Step S18B: Analyze the difference graph through an algorithm and generate an evaluation of whether the optical machine to be tested needs to be calibrated according to the analysis result.

In one embodiment, when the difference pattern calculated in step S18A has a very detailed moiré signal, then step S18B will analyze the difference pattern through an algorithm and generate the setting of the integration range parameters of the optical machine to be tested according to the analysis result. The evaluation to be corrected is used to inform the user that the setting of the integration range parameters of the optical machine under test needs to be corrected.

In another embodiment, when the difference pattern calculated in step S18A has a large range of moiré signals, step S18B will analyze the difference pattern through an algorithm and generate the setting of the focus parameters of the optical machine to be tested according to the analysis result. The evaluation of the need for correction, so as to inform the user that the setting of the focus parameters of the optical machine to be tested needs to be corrected.

In another embodiment, when the difference pattern calculated in step S18A has local brightness unevenness, step S18B will analyze the difference pattern through an algorithm and generate the exposure time setting of the optical machine to be tested according to the analysis result to be corrected. to inform the user that the exposure time setting of the optical machine to be tested needs to be corrected.

In another embodiment, when the difference pattern calculated in step S18A has large-scale uneven brightness, step S18B will analyze the difference pattern through an algorithm and generate the setting requirements of the uniform field of the optical machine to be tested according to the analysis result. Correction evaluation, in order to inform the user that the setting of the uniform field of the optical machine under test needs to be corrected.

It should be noted that, in the embodiment of step S18, only common problems of the optical machine are listed, but not limited thereto.

When the difference pattern calculated in step S18A has an abnormal pattern (as shown in FIG. 10B ), step S18B can analyze the difference pattern through an algorithm and generate an evaluation that the setting of the optical machine under test needs to be corrected according to the analysis result, so as to notify the user It is necessary to correct the settings of the optical machine to be tested.

Therefore, the user can perform correction, such as increasing the exposure time, to effectively remove uneven brightness (as shown in FIG. 10C ). On the contrary, when the difference graph calculated in step S18A has no uneven brightness (as shown in FIG. 11B ), the user does not need to correct the optical machine to be tested.

Compared with the prior art, the present invention provides an optical machine inspection method, which can obtain both the actual brightness generated by the conversion of the test pattern through the optical conversion function and the captured brightness obtained after the test pattern is photographed and calculated by the optical machine to be tested. The difference pattern between the two is analyzed through an algorithm to determine whether there is any abnormality in the difference pattern, so as to determine whether the parameter setting of the optical machine to be tested needs to be corrected. Therefore, the optical machine inspection method of the present invention can achieve the specific effect of quickly inspecting the optical machine to be tested, and can correct the parameter setting of the optical machine to be tested according to the inspection result to eliminate abnormality.

S10~S20: Steps ULA: Grayscale Adjustable Uniform Light Source Array PC: computer TP: Test Pattern DUT: optical machine to be tested PC1: Computer PC2: Computer CB: capture brightness AB: Actual brightness 3: Grayscale adjustable uniform light source array LS: light source LN1: first lens LN2: Second lens PT: penetration unit 4: Grayscale adjustable uniform light source array VR: Vertical Reflection Unit 5: Grayscale adjustable uniform light source array DMD: oblique reflection unit 6: Gray-scale adjustable uniform light source array H1: The first diffuser H2: Second Diffuser 7: Grayscale adjustable uniform light source array LG: light guide plate DF: Diffuser 8: Grayscale adjustable uniform light source array LP: light guide column S18A~S18B: Steps MURA: uneven brightness

The accompanying drawings of the present invention are described as follows: FIG. 1 is a flow chart illustrating an optical machine inspection method according to a preferred embodiment of the present invention. FIG. 2A is a schematic diagram corresponding to step S10 in FIG. 1 . FIG. 2B is a schematic diagram corresponding to steps S12 to S16 in FIG. 1 . FIG. 3 is a schematic diagram illustrating that the gray-scale tunable uniform light source array is designed as a transmission type. FIG. 4 is a schematic diagram illustrating that the gray-scale tunable uniform light source array is designed as a vertical reflection type. FIG. 5 is a schematic diagram illustrating that the gray-scale tunable uniform light source array is designed as an oblique reflection type. FIG. 6 is a schematic diagram illustrating that the uniform light source array with adjustable gray scale is designed as a light diffuser. FIG. 7 is a schematic diagram illustrating that the gray-scale tunable uniform light source array is designed as a light guide plate type. FIG. 8 is a schematic diagram illustrating that the gray-scale tunable uniform light source array is designed as a light guide column. FIG. 9 is a flowchart showing that step S18 in FIG. 1 further includes steps S18A-S18B. FIGS. 10A to 10C are schematic diagrams respectively showing that when the difference pattern has brightness unevenness (Mura), the correction for increasing the exposure time can be performed and the brightness unevenness can be effectively removed. FIGS. 11A to 11B are schematic diagrams respectively illustrating when the difference graph does not have uneven brightness (Mura) and therefore does not need to be corrected.

S10~S20: Steps

Claims (15)

An optical machine inspection method, comprising the following steps: (a) Designing a gray-scale adjustable uniform light source array to measure the gray-scale brightness change information provided by a light source; (b) inputting a test pattern to the gray-scale adjustable uniform light source array; (c) calculating an actual brightness according to the test pattern; (d) An optical machine to be tested captures the test pattern and obtains a captured luminance after calculation; and (e) According to the difference between the actual brightness and the captured brightness, an evaluation of whether the optical machine to be tested needs to be calibrated is generated. The optical machine inspection method according to claim 1, further comprising: (f) Correction is made automatically to provide the correct optical machine shooting environment. The optical machine inspection method according to claim 1, wherein the light source can be a laser, a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL) or other light sources. The optical machine inspection method according to claim 1, wherein when the gray-scale tunable uniform light source array is designed as a transmission type, the gray-scale tunable uniform light source array includes a first lens, a second lens and a A penetration unit, the light emitted by the light source passes through the first lens, the second lens and the penetration unit in sequence to be emitted to the optical machine to be tested. The optical machine inspection method according to claim 1, wherein when the gray-scale adjustable uniform light source array is designed as a vertical reflection type, the gray-scale adjustable uniform light source array includes a first lens, a second lens and a a vertical reflection unit, the light emitted by the light source passes through the first lens and the second lens in sequence and is vertically reflected by the vertical reflection unit to the optical machine to be tested. The optical machine inspection method according to claim 1, wherein when the gray-scale adjustable uniform light source array is designed as an oblique reflection type, the gray-scale adjustable uniform light source array comprises a first lens, a second lens and an oblique reflection unit, the light emitted by the light source passes through the first lens and the second lens in sequence and is obliquely reflected by the oblique reflection unit to the optical machine to be tested. The optical machine inspection method according to claim 1, wherein when the gray-scale adjustable uniform light source array is designed as a light homogenizer, the gray-scale adjustable uniform light source array includes a first lens, a first uniform light source device, a second homogenizer, a second lens and a penetrating unit, the light emitted by the light source passes through the first lens, the first homogenizer, the second homogenizer, and the second lens in sequence and the penetrating unit and then shoot to the optical machine to be tested. The optical machine inspection method according to claim 1, wherein when the gray-scale adjustable uniform light source array is designed as a light guide plate type, the gray-scale adjustable uniform light source array includes a light guide plate, a diffuser and a transparent mold The light emitted by the light source passes through the light guide plate, the diffuser and the transparent module in sequence and then is emitted to the optical machine to be tested. The optical machine inspection method according to claim 1, wherein when the gray-scale adjustable uniform light source array is designed as a light guide column type, the gray-scale adjustable uniform light source array includes a light guide column and a transparent module, the light source The emitted light passes through the light guide column and the transparent module in sequence and then is emitted to the optical machine to be tested. The optical machine inspection method as claimed in claim 1, wherein step (c) is to convert the test pattern through an optical conversion function to generate the actual luminance. The optical machine inspection method as claimed in claim 1, wherein step (e) comprises the following steps: (e1) calculating a difference graph between the actual luminance and the captured luminance; and (e2) Analyzing the difference graph through an algorithm and generating an evaluation of whether the optical machine to be tested needs to be calibrated according to the analysis result. The optical machine inspection method as claimed in claim 11, wherein when the difference pattern has a relatively fine moiré signal, step (e2) generates an evaluation that the setting of the integration range parameter of the optical machine to be tested needs to be corrected. The optical machine inspection method according to claim 11, wherein when the difference pattern has moiré signals in a wide range, step (e2) generates an evaluation that the setting of the focus parameter of the optical machine to be tested needs to be corrected. The optical machine inspection method according to claim 11, wherein when the difference pattern has local brightness unevenness, step (e2) generates an evaluation that the setting of the exposure time of the optical machine to be tested needs to be corrected. The optical machine inspection method according to claim 11, wherein when the difference pattern has large-scale uneven brightness, step (e2) generates an evaluation that the setting of the uniform field of the optical machine to be tested needs to be corrected.

Images