WO2015129531A1

WO2015129531A1 - Inspection device, inspection method, program, and recording medium

Info

Publication number: WO2015129531A1
Application number: PCT/JP2015/054526
Authority: WO
Inventors: 正敬近藤; 北島　功朗; 稲葉　豊
Original assignee: オムロン株式会社
Priority date: 2014-02-25
Filing date: 2015-02-19
Publication date: 2015-09-03
Also published as: CN105934665B; JP2015158440A; JP6318694B2; CN105934665A

Abstract

This inspection device, which inspects articles comprising sheet-shaped optical components laminated together, has an electrostatic charging unit that electrostatically charges optical components and an inspection unit that inspects an article with the optical components therein electrostatically charged.

Description

Inspection device, inspection method, program, and recording medium

The present invention relates to an inspection apparatus, an inspection method, a program, and a recording medium.

Conventionally, an inspection apparatus for inspecting an object to be inspected such as a backlight panel is known (for example, see Patent Document 1).

The inspection apparatus of Patent Document 1 includes a line sensor camera that captures an image of a backlight panel from directly above, and two line sensor cameras that capture an image of the backlight panel from obliquely above, and the imaging results of these line sensor cameras. Is configured to detect defects based on For this reason, by moving one line sensor camera, it is possible to shorten the inspection time as compared with the case of imaging the backlight panel while changing the angle of the line sensor camera with respect to the backlight panel. .

JP 2007-333449 A

Here, in the inspected object in which the sheet-like optical components are laminated, a gap is easily generated between the optical components. And if there is a gap between the optical components during the inspection by the inspection device, luminance unevenness occurs due to the gap, which makes it difficult to determine the defect. It is difficult to plan. The inspection apparatus disclosed in Patent Document 1 has the same problem.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an inspection apparatus, an inspection method, a program, and a recording medium capable of improving the accuracy of defect detection. is there.

An inspection apparatus according to the present invention inspects an object to be inspected on which sheet-like optical components are stacked, and inspects a charging unit that charges the optical component and an object to be inspected in a state where the optical component is charged. A part.

With this configuration, the gap between the optical components can be reduced by adsorbing the optical components to each other during inspection. Thereby, since the brightness nonuniformity resulting from a clearance gap can be suppressed, a defect can be made easy to detect. As a result, the accuracy of defect detection can be improved.

The inspection apparatus may include a static elimination unit that neutralizes an object to be inspected by the inspection unit.

With this configuration, it is possible to suppress the adhesion of dust and the like after the inspection and to suppress the occurrence of electrostatic breakdown.

The inspection apparatus may include a protection circuit that protects the object to be inspected.

If configured in this way, it is possible to suppress the object to be inspected from being damaged during inspection.

In the inspection apparatus, the inspection unit may include an imaging unit that images the object to be inspected and a determination unit that determines the presence or absence of a defect based on an imaging result of the imaging unit.

With this configuration, it is possible to determine the presence or absence of a defect based on the imaging result.

In the above inspection apparatus, the object to be inspected may include a backlight.

This configuration allows the backlight to be inspected.

The inspection method according to the present invention is for inspecting an object to be inspected on which sheet-like optical components are laminated. The step of charging the optical component, and the step of inspecting the object to be inspected with the optical component charged. Is provided.

The program according to the present invention is for causing a computer to execute the above-described inspection method.

The recording medium according to the present invention records a program for causing a computer to execute the above-described inspection method.

According to the inspection apparatus, inspection method, program, and recording medium of the present invention, it is possible to improve the accuracy of defect detection.

FIG. 1 is a block diagram showing a schematic configuration of an inspection apparatus according to an embodiment of the present invention. FIG. 2 is an exploded perspective view showing an example of a backlight inspected by the inspection apparatus. FIG. 3 is a circuit diagram showing a protection circuit of the inspection apparatus of FIG. FIG. 4 is a schematic diagram showing a state before the backlight is charged. FIG. 5 is a schematic diagram showing a state in which the backlight is charged. FIG. 6 is a graph showing the inspection result of the inspection apparatus according to the comparative example. FIG. 7 is a graph showing the inspection result of the inspection apparatus according to the example corresponding to the present embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, a schematic configuration of an inspection apparatus 100 according to an embodiment of the present invention will be described with reference to FIGS.

The inspection apparatus 100 (see FIG. 1) is configured to inspect the backlight 200 (see FIG. 2). Specifically, the inspection apparatus 100 is configured to determine whether or not there is a defect at each position in plan view of the backlight 200 based on luminance unevenness when the backlight 200 is turned on. Yes. As an example of the cause of the defect, there is an intrusion of foreign matter such as dust or a scratch.

Here, the backlight 200 inspected by the inspection apparatus 100 is, for example, a surface light source device that illuminates liquid crystal from the back. The backlight 200 is an example of the “inspection object” in the present invention.

As shown in FIG. 2, the backlight 200 includes a plurality of LEDs (light emitting diodes) 201, a light guide plate 202, a diffusion sheet 203,

prism sheets

204 and 205, a frame 206 that accommodates them, and a frame 206. And a reflecting plate 207 provided on the lower surface side of the. The light guide plate 202, the diffusion sheet 203, and the

prism sheets

204 and 205 are examples of the “optical component” in the present invention.

The plurality of LEDs 201 are provided on an FPC (flexible printed wiring board) 208 and are arranged along a side surface of the light guide plate 202 at a predetermined interval. The light guide plate 202 is configured to cause the light emitted from the LEDs 201 to emit light. On the upper surface of the light guide plate 202, a diffusion sheet 203 and

prism sheets

204 and 205 are laminated. A double-sided tape 209 having a light shielding property is attached to the outer edge portion of the upper surface of the prism sheet 205 and the upper surface side of the frame 206.

In such a backlight 200, the light guide plate 202, the diffusion sheet 203, and the

prism sheets

204 and 205 are thin sheet-like components. A gap H (see FIG. 4) may be generated between the diffusion sheet 203 and the prism sheet 204 and between the prism sheet 204 and the prism sheet 205. Therefore, the inspection apparatus 100 according to the present embodiment is configured to inspect the backlight 200 with the gap H reduced.

Specifically, as shown in FIG. 1, the inspection apparatus 100 includes a charging unit 1, an inspection unit 2, and a charge removal unit 3.

The charging unit 1 is provided to charge the light guide plate 202, the diffusion sheet 203, and the

prism sheets

204 and 205 of the backlight 200. The charging unit 1 is configured to generate anions N (see FIG. 4) and supply the anions N to the surface 200a of the backlight 200 (see FIG. 4).

The inspection unit 2 is configured to inspect the backlight 200 (see FIG. 5) in a state where the light guide plate 202, the diffusion sheet 203, and the

prism sheets

204 and 205 are charged. The inspection unit 2 includes an imaging unit 21 that images the backlight 200, a data processing unit 22 that processes image data captured by the imaging unit 21, and the presence or absence of defects based on the data processed by the data processing unit 22. And a determination unit 23 for determining

The imaging unit 21 is an area sensor, for example, and has a function of imaging the entire surface 200a of the backlight 200. The data processing unit 22 is configured to process the image data obtained by the imaging unit 21 based on a predetermined algorithm. The determination unit 23 is configured to determine whether or not the luminance at each position of the backlight 200 is within a predetermined range based on the data processed by the data processing unit 22. Then, the determination unit 23 determines that there is no defect in a portion where the luminance is within the predetermined range, and determines that there is a defect in a portion where the luminance is outside the predetermined range.

The neutralization unit 3 is provided to neutralize the backlight 200 inspected by the inspection unit 2. The static elimination unit 3 is configured to generate cations and anions and supply the cations and anions to the surface 200 a of the backlight 200. The neutralization unit 3 has a function of neutralizing and removing the anions N adsorbed on the surface 200 a of the backlight 200.

Further, as shown in FIG. 3, the inspection apparatus 100 is provided with a DC power supply 4 and a protection circuit 5. The DC power supply 4 is provided to turn on the backlight 200 during inspection. The protection circuit 5 is disposed between the DC power supply 4 and the backlight 200 and is provided to suppress an overcurrent from flowing through the LED 201 of the backlight 200. Specifically, the protection circuit 5 includes a Zener diode 5 a, the anode of the Zener diode 5 a is connected to the negative side of the DC power supply 4, and the cathode of the Zener diode 5 a is connected to the positive side of the DC power supply 4. .

The inspection apparatus 100 is provided with a computer (not shown) for controlling the inspection apparatus 100. The computer includes a recording medium on which a program for executing an inspection method described later is recorded. That is, the inspection apparatus 100 is controlled to perform an inspection method described later by the computer when the program is executed by the computer.

-Inspection method-
Next, an inspection method for the backlight 200 by the inspection apparatus 100 according to the present embodiment will be described with reference to FIGS.

First, the backlight 200 (see FIG. 2) to be inspected is installed in a transport device (not shown) such as an index table. Then, the backlight 200 is connected to the DC power supply 4 via the protection circuit 5 as shown in FIG. Thereafter, the backlight 200 is transported to the charged region by the transport device.

Next, as shown in FIG. 4, the anion N is generated by the charging unit 1 (see FIG. 1), and the anion N is supplied to the surface 200 a of the backlight 200. Thereby, as shown in FIG. 5, the anion N is adsorbed on the surface 200a of the backlight 200, and the backlight 200 is charged. More specifically, the upper surface side of the prism sheet 205 is positively charged and the lower surface side of the prism sheet 205 is negatively charged by the anions N adsorbed on the surface 200a. Accordingly, in the prism sheet 204, the diffusion sheet 203, and the light guide plate 202, the upper surface side is positively charged, and the lower surface side is negatively charged.

For this reason, the prism sheet 205 and the prism sheet 204 are adsorbed, the prism sheet 204 and the diffusion sheet 203 are adsorbed, and the diffusion sheet 203 and the light guide plate 202 are adsorbed. Thereby, the gap H (see FIG. 4) between the sheets is reduced. Thereafter, the charged backlight 200 is transported to the inspection area by the transport device.

Next, a current is supplied from the DC power source 4 to the LED 201 of the backlight 200, and the backlight 200 is turned on. At this time, since the voltage between the plurality of LEDs 201 connected in series does not exceed a predetermined value by the protection circuit 5, no overcurrent flows through the LEDs 201.

Then, the entire surface 200a of the backlight 200 is imaged by the imaging unit 21 (see FIG. 1). Thereafter, the data processing unit 22 (see FIG. 1) processes the image data obtained by the imaging unit 21 based on a predetermined algorithm.

Next, based on the data processed by the data processing unit 22, the determination unit 23 (see FIG. 1) determines whether or not the luminance at each position of the backlight 200 is within a predetermined range. Then, it is determined that there is no defect for a portion whose luminance is within a predetermined range, and it is determined that there is a defect for a portion whose luminance is outside the predetermined range. That is, in the present embodiment, the light guide plate 202, the diffusion sheet 203, and the

prism sheets

204 and 205 are charged, and the backlight 200 in a state where the gap H between them is reduced is inspected by the inspection unit 2.

Thereafter, the supply of current from the DC power supply 4 to the LED 201 is stopped. And the backlight 200 by which the test | inspection was complete | finished is conveyed by the conveyance apparatus to a static elimination area.

Next, the cation and the anion are generated by the static eliminating unit 3 (see FIG. 1), and the cation and the anion are supplied to the surface 200a of the backlight 200. Thereby, the anion N adsorbed on the surface 200a of the backlight 200 is neutralized and removed. For this reason, the charged state of the prism sheet 205, the prism sheet 204, the diffusion sheet 203, and the light guide plate 202 is eliminated. Thereafter, the neutralized backlight 200 is removed from the transport device.

-effect-
In the present embodiment, as described above, the charging unit 1 that charges the backlight 200 and the inspection unit 2 that inspects the charged backlight 200 are provided. With this configuration, the light guide plate 202, the diffusion sheet 203, and the

prism sheets

204 and 205 are adsorbed to each other at the time of inspection, whereby the gap H between them can be reduced. Thereby, since the brightness nonuniformity resulting from the clearance gap H can be suppressed, a defect can be easily detected. As a result, the accuracy of defect detection can be improved.

Moreover, since the gap H can be reduced without contact, the accuracy of defect detection can be improved without damaging the backlight 200.

Moreover, in this embodiment, by providing the static elimination part 3 which neutralizes the backlight 200 test | inspected by the test | inspection part 2, while suppressing that dust etc. adhere after an test | inspection, generation | occurrence | production of electrostatic breakdown is suppressed. be able to.

Further, in the present embodiment, by providing the protection circuit 5, it is possible to suppress an overcurrent from flowing through the LED 201 at the time of inspection, and thus it is possible to suppress the LED 201 from being damaged.

-Experimental example-
Next, with reference to FIG. 6 and FIG. 7, the experiment conducted in order to confirm the effect of this embodiment mentioned above is demonstrated. In this experiment, the backlight was inspected by the inspection apparatus according to the comparative example, and the backlight was inspected by the inspection apparatus according to the example corresponding to this embodiment.

In the inspection apparatus according to the comparative example, the optical components (light guide plate, diffusion sheet, and prism sheet) on which the backlight is laminated are inspected in an uncharged state. In the inspection apparatus according to the embodiment, the backlight is laminated. Inspection was performed with the optical parts charged. Further, the backlight to be inspected has defects formed in advance at a predetermined position P (see FIGS. 6 and 7), and the same backlight was used in the comparative example and the example. And the test result of the test | inspection apparatus by a comparative example was shown in FIG. 6, and the test result of the test | inspection apparatus by an Example was shown in FIG. In FIGS. 6 and 7, the vertical axis represents the luminance, the horizontal axis represents the position, and the inspection result of the predetermined linear region including the position P where the defect is formed is shown.

As shown in FIG. 6, in the inspection result of the inspection apparatus according to the comparative example, the luminance unevenness at each position of the backlight was large. This is considered to be due to the large influence of the gap generated between the optical components of the backlight. For this reason, since it is necessary to widen the predetermined range (luminance range in which it is determined that there is no defect) R1 for determining the presence / absence of a defect, the defect formed at the position P cannot be detected. That is, in the inspection apparatus according to the comparative example, the luminance unevenness due to the defect is almost the same as the luminance unevenness due to the gap, and it is difficult to discriminate these. Note that if the predetermined range R1 is narrowed in order to detect luminance unevenness due to a defect, the luminance unevenness due to the gap is erroneously detected as a defect.

On the other hand, as shown in FIG. 7, in the inspection results of the inspection apparatus according to the example, the luminance unevenness at each position of the backlight was reduced as compared with the comparative example. This is presumably because the optical components of the backlight are charged and the optical components are attracted to each other, and the gap between the optical components is reduced. Note that the luminance unevenness at the position P is caused by a defect, and therefore remains at the same level as in the comparative example. For this reason, since the brightness at the position P is outside the predetermined range R2 by narrowing the predetermined range R2 for determining the presence or absence of defects compared to the comparative example, the defect formed at the position P is appropriately detected. We were able to. That is, in the inspection apparatus according to the example, the luminance unevenness due to the defect can be made obvious by reducing the luminance unevenness due to the gap, and thus the defect can be appropriately detected. As a result, the accuracy of defect detection could be improved. In this experiment, since the luminance unevenness of the example could be reduced to about 2/3 of the comparative example, the predetermined range R2 could be set to about 2/3 of the predetermined range R1.

-Other embodiments-
In addition, embodiment disclosed this time is an illustration in all the points, Comprising: It does not become a basis of limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiments, but is defined based on the description of the scope of claims. Further, the technical scope of the present invention includes all modifications within the meaning and scope equivalent to the scope of the claims.

For example, in the present embodiment, the backlight 200 is shown as an example of an object to be inspected. However, the present invention is not limited to this, and the object to be inspected may be a laminate of sheet-like optical components.

In the present embodiment, the diffusion sheet 203 and the

prism sheets

204 and 205 are stacked on the upper surface of the light guide plate 202. However, the present invention is not limited to this. It may be something like this.

In the present embodiment, the charging unit 1 generates the negative ions N. However, the present invention is not limited thereto, and the charging unit may generate positive ions.

In the present embodiment, the example in which the imaging unit 21 is an area sensor has been described. However, the present invention is not limited thereto, and the imaging unit may be a line sensor.

The present invention can be used for an inspection apparatus, an inspection method, a program, and a recording medium for inspecting an object to be inspected on which sheet-like optical components are stacked.

DESCRIPTION OF SYMBOLS 1 Charging part 2 Inspection part 3 Static elimination part 5 Protection circuit 21 Imaging part 23 Determination part 100 Inspection apparatus 200 Backlight (inspection object)
202 Light guide plate (optical component)
203 Diffusion sheet (optical component)
204 Prism sheet (optical component)
205 Prism sheet (optical component)

Claims

An inspection apparatus for inspecting an object to be inspected on which sheet-like optical components are laminated,
A charging unit for charging the optical component;
An inspection apparatus comprising: an inspection unit that inspects the inspection target in a state where the optical component is charged.
The inspection apparatus according to claim 1,
An inspection apparatus comprising: a static elimination unit that neutralizes the object to be inspected by the inspection unit.
The inspection apparatus according to claim 1 or 2,
An inspection apparatus comprising a protection circuit for protecting the object to be inspected.
The inspection apparatus according to any one of claims 1 to 3,
The inspection apparatus includes: an imaging unit that images the object to be inspected; and a determination unit that determines presence / absence of a defect based on an imaging result of the imaging unit.
The inspection apparatus according to any one of claims 1 to 4,
The inspection apparatus includes a backlight.
An inspection method for inspecting an object to be inspected on which sheet-like optical components are laminated,
Charging the optical component; and
And a step of inspecting the inspection object in a state where the optical component is charged.
A program for causing a computer to execute the inspection method according to claim 6.
A recording medium on which a program for causing a computer to execute the inspection method according to claim 6 is recorded.