KR20080009943A - Apparatus and method for inspecting alien substances - Google Patents

Abstract

An apparatus and a method for inspecting a foreign substance in a camera module are provided to divide a foreign substance inspection operation into a macro inspection using a uniform light and a micro inspection using an intensive light and perform the foreign substance inspection according to the degree of difficulty, thereby reducing an operation time and efforts. An apparatus for inspecting a foreign substance(100) in a camera module(10) comprises a first lighting unit(160), a second lighting unit(140), and a lens unit(150). The first lighting unit is used as a subject of the camera module for a macro inspection. The second lighting unit is used as a subject of the camera module for a micro inspection. The lens unit is positioned between the second lighting unit and the camera module to concentrate light radiated from the second lighting unit to the lens of the camera module.

Description

Camera module foreign material inspection device and inspection method {APPARATUS AND METHOD FOR INSPECTING ALIEN SUBSTANCES}

1 is a schematic view showing a camera module foreign material inspection apparatus according to a preferred embodiment of the present invention;

Figure 2 is a schematic diagram showing a configuration for rotating the lens unit mounting plate of Figure 1;

3 is a schematic cross-sectional view showing a first lighting unit of FIG.

4 is a schematic diagram illustrating image information obtained by photographing the first or second lighting unit by using the camera module of FIG. 1 as a subject;

5 is a schematic diagram showing a luminance waveform obtained along the vertical line of FIG. 4;

6 is a flowchart illustrating a method of inspecting a foreign material of a camera module with the inspection device of FIG. 1;

7 is a detailed flowchart illustrating a process of inspecting a foreign material with the inspection device of FIG. 1 according to the flowchart of FIG. 6;

8 is a schematic cross-sectional view of a general camera module;

9 is a schematic view of a conventional camera module foreign material inspection apparatus; And

10 is a schematic diagram showing a luminance waveform obtained by the inspection apparatus of FIG.

<Explanation of symbols for main parts of drawing>

100: inspection device 110: fixed pillar

120: Shanghai East pillar 121: Mounting table

125: pedestal 130: moving block

131: forward and backward moving block 133: left and right moving block

135: support plate 140: second lighting unit

141: light source 145: support

150 lens unit 151 housing

152: lens unit 153: driving cylinder

154: lens unit mounting plate 155: connecting rod

156: Link 160: Article 1 lighting

161: housing 162: light source unit

163: chart 166: drive cylinder

170: camera module mounting portion 171: fixed block

175: Pin Block Zig

The present invention relates to a foreign material inspection device and an inspection method, and more particularly to a camera module foreign material inspection device and inspection method that can accurately inspect the foreign matter on the lens of the camera module or the image pickup device.

The camera module, for example, is configured as shown in FIG. The solid state imaging element 2 is mounted on the substrate 1 and the base 3 is disposed so as to cover the outer circumference thereof. In the upper part of the base 3, the base 3 is positioned so that the center axis of the cylinder part 3a may match the center of the light receiving part of the solid state image pickup device 2. The optical filter 4 is adhesively fixed to the base 3. On the outer periphery of the cylindrical part 3a of the base 3, the screw part 3b is formed coaxially with respect to the central axis. The lens 5 for forming an image on the solid state image pickup device 2 is incorporated in the rib 6b of the lens holder 6, held by the lens cap 7, and formed coaxially with respect to the optical axis of the lens 5. It is. By screwing the screw portion 6a to the screw portion 3b, the optical axis of the lens 5 and the center of the light receiving portion of the solid state image pickup device 2 are positioned to coincide. Focus adjustment is performed while the lens holder 6 is screwed and moved, and the adhesive is fixed at an appropriate position.

The camera module is subjected to a foreign material inspection operation to check whether there is any foreign matter on the lens or the image pickup device after the assembling work is completed. An example of the foreign material inspection device and inspection method used here is described in Japanese Patent Application Laid-Open No. 2002-290994. Foreign material inspection method and foreign material inspection device of the camera module.

As shown in FIG. 9, the conventional foreign material inspection apparatus includes a light source 5 for irradiating uniform light to the small camera module 1 and an image memory for storing image information output from the signal processing circuit 4 ( 6) and an arithmetic circuit 7 for calculating and processing arbitrary image information by calculating image information stored in the image memory 6, and scanning horizontal lines by image information in any one horizontal direction line. Means for detecting the position of the maximum luminance by sequentially comparing the luminance from the start position to the scan end position, means for collecting the difference in luminance between pixels adjacent to the position direction of the maximum luminance from the scanning start position on the horizontal line, and the horizontal line Means for collecting the difference in luminance between pixels adjacent to the position direction of maximum luminance from the scanning end position of; and the difference between the luminance of the reference pixel and the reference pixel Means are provided for judging the comparison pixel as bad when the difference with the luminance of the comparison pixel near the large luminance position is negative and less than the determination value.

However, since the conventional foreign material inspection apparatus having the above-described configuration uses a light source for irradiating uniform light, the illuminance is not excellent, and thus, the scanning starting position 10 from the horizontal line to the scanning end position 11 as shown in FIG. Luminance change did not appear much. Because of this, it is difficult to detect the position of the maximum luminance when the foreign material inspection using the device actually, it is difficult to increase the accuracy and reliability of the operation.

In addition, since the inspection work is made indiscriminately regardless of the difficulty of the foreign material inspection, even when the foreign material inspection is easy, the same work time and effort were required as in the case of the foreign material inspection, which was not efficient.

The present invention has been made to solve the above-mentioned problems of the prior art, the object of the present invention is to carry out the inspection work divided into two stages, that is, macroscopic inspection using uniform light and microscopic inspection using concentrated light In addition, it is possible to vary the working time and effort according to the degree of difficulty, and to provide a camera module foreign material inspection device that can increase the precision and reliability of inspection by increasing the luminance change during micro inspection.

Another object of the present invention to provide a test method for inspecting the foreign matter of the camera module using the foreign matter inspection apparatus.

In order to achieve the above object of the present invention, the present invention provides a first lighting unit that is the subject of the camera module for the macroscopic inspection, a second lighting unit that is the subject of the camera module for the microscopic examination, the second lighting unit and the camera module The camera module is provided with a foreign material inspection device, characterized in that it comprises a lens unit located between and to focus the light irradiated from the second lighting unit to the lens of the camera module.

The inspection apparatus of the present invention is characterized in that the first lighting unit includes a light source unit and a chart for irradiating uniform light, and the chart is white.

The second lighting unit is characterized in that it comprises a light source for irradiating the concentrated light, the light source is also characterized in that the coaxial light.

It is characterized in that the lens unit is installed to be movable toward the camera module, the lens unit is capable of rotating the shaft at a predetermined angle.

The lens unit is characterized in that it comprises a cylindrical objective lens.

The change in luminance of the image information obtained by the camera module photographing the first lighting unit as the subject is smaller than the change in luminance of the image information obtained by photographing the second lighting unit as the subject.

The present invention also obtains the primary image information by photographing the first lighting unit as a subject with the camera module, and (B) compares the primary image information obtained in the step (A) with the reference image information on a macroscopic basis. (C) photographing the second lighting unit as a subject to obtain secondary image information if a foreign object is not detected in (C) and (B), and (D) obtaining the second image information. Inspecting the foreign material microscopically by comparing the secondary image information with the reference image information, and (E) If the foreign material is not detected in (D), the camera module is judged as good quality. It provides a camera module foreign material inspection method comprising the step of determining and finishing the inspection.

The inspection method of the present invention is characterized in that the inspection of the step (B) includes a color point, foreign matter, horizontal or vertical inspection of the camera module.

Inspection of step (D) is characterized in that it comprises a moire, agglomeration, bond, black spots, scratches, color or uniformity inspection of the camera module.

The comparison between the primary image information, the secondary image information, and the reference image of steps (B) and (D) is performed by template matching.

Hereinafter, with reference to the accompanying drawings will be described in detail a camera module foreign material inspection apparatus and inspection method according to a preferred embodiment of the present invention.

First, the foreign material inspection apparatus according to the present embodiment will be described with reference to FIGS. 1 to 3.

As schematically shown in FIG. 1, the inspection apparatus 100 includes a stationary pillar 110, a shandong copper pillar 120, a movable block 130, a second lighting unit 140, a lens unit 150, and a first unit. The lighting unit 160 and the camera module mounting unit 170 are included.

The fixing column 110 is for supporting other parts except the camera module mounting unit 170 and is fixedly installed on the base 101 installed firmly on the ground.

Shanghai copper pillar 120 is for supporting the moving block 130, the second lighting unit 140 and the lens unit 150, the fixed pillar 110 to be moved up and down by a predetermined driving means (not shown) It is installed in). The shanghai copper column 120 has a mounting table 121 installed on the fixing column 110 and a pedestal 125 extending from the mounting table 121. The pedestal 125 is fixed to the mounting table 121.

The moving block 130 is for supporting the second lighting unit 140 and the lens unit 150, and the shank copper pillar 120 may be moved back and forth and / or left and right by a predetermined driving means (not shown). It is installed on the pedestal 125. The movement block 130 includes a front and rear movement block 131 and a left and right movement block 133. The front and rear movement block 131 is installed on the pedestal 125 so as to be movable back and forth with respect to the pedestal 125, and the left and right movement block 133 is movable back and forth with respect to the front and rear movement block 131. ) Is installed on top. The support plate 135 for supporting the second lighting unit 140 is fixedly installed on the left and right moving blocks 133. Opening plate 137 is formed in the support plate 135 to allow light to pass through a position corresponding to the light source 141.

The second lighting unit 140 is for irradiating the microscopic inspection of the foreign material of the camera module 10, that is, for the second inspection. The second lighting unit 140 serves as a light source 141 and a support 145 for supporting the light source 141. It is composed. The light source 141 uses coaxial light for irradiating concentrated light, and is installed on the support 145 to adjust the height up and down by an operator. The support 145 is installed to be fixed to the support plate 135.

The lens unit 150 is for condensing the light emitted from the second lighting unit 130 to the lens (not shown) of the camera module 10, the housing 151, the lens unit 152 and the driving cylinder 153 It consists of. The housing 151 is for storing the lens unit 152 and is installed coaxially with the light source 141 on the lower surface of the support plate 135, and the lower side thereof is opened to protrude a portion of the lens unit 152. As shown in more detail in Figure 2, the lens unit 152 is fixed to the annular lens unit mounting plate 154 as a cylindrical objective lens and a plurality of objective lenses are installed therein. The lens unit mounting plate 154 is connected to the driving cylinder 153 by the connecting table 155 and the link 156. A rectangular hole 157 is formed in the link 156 and a protrusion 158 is formed in the connecting table 155 so that the protrusion 158 of the connecting table 155 is inserted into the rectangular hole 157 of the link 156. do. Connecting table 155 and the lens unit mounting plate 154 is fixedly coupled. The link 156 may move back and forth as shown by an arrow by the driving force of the driving cylinder 153 fixedly installed on the support plate 135, and the lens unit mounting plate 154 and the lens unit 152 are clockwise in accordance with this movement. Or counterclockwise. That is, if the link 156 moves in the direction of arrow A1, the lens unit mounting plate 154 and the lens unit 152 will move in the direction of arrow A2, and if the link 156 moves in the direction of arrow B1, the lens unit mounting plate 154 will move. And the lens unit 152 will move in the direction of arrow B2.

The first lighting unit 160 is for irradiating light at the macroscopic inspection, that is, at the first inspection of the foreign material of the camera module 10, as shown in more detail in FIG. 3, the box-shaped housing 161 and the light source unit. 162 and the chart 163. The housing 161 is formed such that the storage spaces 164 and 165 for separately storing the light source unit 162 and the chart 163 therein are separated up and down. The light source unit 162 is composed of a plurality of laser light emitting diodes. The chart 163 is preferably manufactured in white to increase the luminance of the image pickup device of the camera module 10. The housing 161 of the first lighting unit 160 is installed on the support plate 167 fixed to the driving cylinder 166, and the support plate 167 is coaxial with the light source 141 of the second lighting unit 140. Open holes 168 through which light passes are formed. The driving cylinder 166 is moved back and forth with respect to the base 101, whereby the first lighting unit 160 is movable back and forth.

The camera module mounting unit 170 is for mounting the camera module 10 to be inspected and includes a fixed block 171 and a pin block jig 175. The fixed block 171 is installed to be fixed to the base 101 coaxially with the light source 141 of the second lighting unit 140, the pin block jig 175 is selected by the operator in accordance with the specifications of the camera module 10 And the fixed block 171 is installed. At this time, the fixed block 171 has a reference pin 173 is formed to help the pin block jig 175 is installed in the correct position.

FIG. 4 is an image photographed by an imaging device (not shown) of the camera module 10 by using light of the first lighting unit 160 or the second lighting unit 140 as a subject. Appear as dots. In the drawing, reference numeral '11' denotes a position where light starts to be scanned, and reference numeral '12' denotes a position where the light ends in scanning.

FIG. 5 shows a luminance waveform formed along a vertical line 1 of the image information shown in FIG. 4 by dotted lines. The luminance waveform indicated by the dotted line indicates that the peripheral luminance is low due to the lens characteristics, and the luminance of the scanning start position 11 and the scanning end position 12 of the vertical line 1 is lower than that of the lens center. The luminance difference between the center and the periphery of the lens is much larger than in the prior art because the use of the concentrated light to increase the scattering of light by the foreign material. The foreign material 2 is represented by a luminance deterioration of several pixels on the luminance waveform. The image information of the foreign material 2 can be detected precisely based on the luminance waveform.

Next, the foreign material inspection method of this embodiment will be described with reference to FIGS. 6 and 7.

For the sake of understanding, an inspection method according to the present exemplary embodiment shown in FIG. 6 divided into five steps and an operation of performing each step using the above inspection apparatus will be described while alternately matching FIG. 7.

First, the first lighting unit 160 is photographed as a subject by the camera module 10 to obtain primary image information (S110). The light scanned by the light source unit 162 of the first lighting unit 160 is uniform light as in the prior art.

In step S110, as shown in FIG. 7, the pin block jig 175 meeting the specification of the camera module 10 to be inspected is installed in the fixed block 171 and the camera to be inspected in the pin block jig 175. Module 10 is mounted. When the operation is started, the driving cylinder 166 is controlled and driven by the controller (not shown) and the first lighting unit 160 moves forward to move upward of the camera module 10 to have a stabilization time. When stabilization is performed, the camera module 10 captures the first lighting unit 160 as a subject to obtain primary image information.

Next, the first foreign material inspection is performed based on the thus obtained primary image information (S120). In this case, the macroscopic inspection is performed by comparing the primary image information and the reference image input in advance, and here, detection is possible only when the foreign material is relatively large.

In operation S120, as shown in FIG. 7, the apparatus 100 is switched to the RGB mode so that the obtained primary image information and the reference image may be subjected to color point / foreignness inspection and horizontal / vertical inspection through comparison of template matching and the like. do.

Next, when foreign matter is detected in the above step (S120), the camera module 10 is determined to be defective and the inspection operation is terminated. Otherwise, the camera module 10 uses the camera module 10 as a light source 141 of the second lighting unit 140. ) As a subject to obtain secondary image information (S130).

In step S130, as shown in Fig. 7, the operation is terminated when the rejection decision is made in the color point / foreign inspection and / or the horizontal / vertical inspection, otherwise, the apparatus 100 is switched to the Y mode and is controlled by the controller. The first lighting unit 160 is moved back to the original position by the reverse of the drive cylinder 166 that is controlled and driven. In this case, the first lighting unit 160 no longer exists above the camera module 10. Subsequently, as the shank copper pillar 120 driven by the control of the controller (not shown) descends, the lens unit 150 slightly descends toward the camera module 10, and the camera module 10 subsequently connects the light source 141. ) As a subject to obtain secondary image information. In this case, when the focus of the lens unit 150 does not match the center of the lens of the camera module 10, the moving block 130 moves back and forth and / or left and right by the controller (not shown). The focus is aligned with the lens center and the lens unit 150 is further lowered to have a stabilization time. When stabilization is performed, the camera module 10 photographs the light source 141 as a subject to obtain secondary image information.

Next, a secondary foreign material inspection is performed based on the obtained secondary image information (S140). At this time, as in step S120, the microscopic inspection is performed by comparing the secondary image information and the previously input reference image with template matching. In this case, detection is possible even when the foreign material is relatively small.

In step S140, as shown in FIG. 7, inspections such as moiré / agglomeration / bond / spot / scratch / color / uniformity are performed. If there is no abnormality in these tests, the registration setting is redone and the test such as sunspot / foreign material / screen blanking is performed again.

Finally, if the foreign matter is not detected in the above step, the camera module 10 is determined to be good and ends the inspection work. If the foreign matter is detected, the camera module 10 is determined to be defective and the inspection work ends (S150).

In step S150, as shown in Fig. 7, the lens unit in the case of a failure determination in the moiré / agglomeration / bond / black spot / scratch / color / uniformity inspection, or in the inspection such as black spot / foreign material / screen, etc. When 150 is raised and the operation is finished, even when a pass decision is made by inspection such as black spots / foreign materials / screening, the lens unit 150 is raised to complete the operation.

In the process of performing the inspection operation of the present embodiment, if there is a foreign material in the lens unit 150, the control unit (not shown) by driving the drive cylinder 153 to drive the lens unit 150 After moving to the outside of the support plate 135 by rotating in the direction, the operator can easily check the presence of foreign objects on the lens unit 150.

The foreign material inspection device and the inspection method of the present invention have been described above with reference to a preferred embodiment of the present invention, but it will be apparent to those skilled in the art that modifications, changes, and various modifications can be made without departing from the spirit of the present invention.

According to the foreign matter inspection apparatus of the camera module of the present invention, since the foreign matter inspection work is divided into two stages, that is, macroscopic examination using uniform light and microscopic examination using focused light, foreign matter inspection can be performed according to difficulty If the work is finished only by inspection, it is not necessary to perform micro-inspection, thus reducing work time and effort.

In addition, when performing the microscopic examination, since the concentrated light of the light source is concentrated on the lens, the brightness of the image information obtained by the camera module is greatly changed, thereby facilitating the inspection and increasing the accuracy and reliability of the inspection.

In addition, since the operator can visually check by rotating the lens unit, it is very easy to check when foreign matter is present in the lens unit.

Claims (13)

A first lighting unit that becomes a subject of a camera module for macroscopic examination; A second lighting unit which becomes a subject of the camera module for microscopic examination; And And a lens unit positioned between the second lighting unit and the camera module to focus light emitted from the second lighting unit to the lens of the camera module. The inspection apparatus according to claim 1, wherein the first lighting unit comprises a light source unit and a chart for irradiating uniform light. The inspection apparatus according to claim 2, wherein the chart is white. The inspection apparatus according to claim 1, wherein the second lighting unit comprises a light source for irradiating concentrated light. 5. The inspection apparatus according to claim 4, wherein the light source is coaxial illumination. The inspection apparatus according to claim 1, wherein the lens unit is installed to be movable toward the camera module. 7. The inspection apparatus according to claim 6, wherein the lens unit is capable of rotating the shaft at a predetermined angle. The inspection apparatus of claim 1, wherein the lens unit comprises a cylindrical objective lens. The inspection apparatus according to claim 1, wherein the brightness change of the image information obtained by the camera module photographing the first lighting unit as a subject is smaller than the change in brightness of image information obtained by photographing the second lighting unit as the subject. (A) photographing the first lighting unit as a subject with a camera module to obtain primary image information; (B) inspecting foreign matter macroscopically by comparing the primary image information obtained in the step (A) with reference image information; (C) obtaining foreign image information by photographing the second lighting unit as a subject when the foreign object is not detected in the step (B); (D) inspecting the foreign material microscopically by comparing the secondary image information obtained in the step (C) with the reference image information; And (E) if the foreign object is not detected in step (D), the camera module is determined to be good, and if the foreign object is detected, determining the camera module as a defective product and including inspecting the camera module. Way. The inspection method according to claim 10, wherein the inspection of the step (B) comprises a color point, a foreign material, a horizontal, or a vertical inspection of the camera module. The inspection method according to claim 10, wherein the inspection of the step (D) comprises a moire, agglomeration, bond, black spot, scratch, color or uniformity inspection of the camera module. The method of claim 10, wherein the comparison between the primary image information, the secondary image information, and the reference image in steps (B) and (D) is performed by template matching.

Images