Surface scratch detection device and detection method for optical glass

Abstract

The present invention relates to the field of detection technology, and specifically to a surface scratch detection device and detection method for optical glass, comprising a platform for mounting glass, and an XY-axis slide module mounted on the platform, wherein the platform has a through-hole design in the middle, and the XY-axis slide module is arranged in two groups, which are respectively mounted above and below the platform, and the heads on the two groups of XY-axis slide modules move synchronously and remain on the same vertical line, a laser transmitter and a laser receiver are fixedly mounted on the bottom of the upper head, and a reflector is fixedly mounted on the top of the lower head; laser light is emitted by the laser transmitter and refracted toward the upper surface of the glass, and then emitted from the inside of the glass to the surface of the reflector and reflected back to the lower surface of the glass and refracted, and finally the laser light passes through the upper surface of the glass and is received by the laser receiver, and when there is a scratch at the incident point of the laser light onto the glass surface, the laser receiver cannot receive the laser light.

Description

Technical Field

[0001] The present invention relates to the field of detection technology, and in particular to a detection device and a detection method for surface scratches of optical glass. Background Art

[0002] ‌The width of glass scratches is usually between 0.1mm and 0.5mm‌. For minor scratches with a width of less than 0.1mm, two scratches with a length of less than 50mm are allowed per square area; for scratches with a width of more than 0.1mm and less than 0.5mm, one scratch is allowed per square area‌;‌ The laser emitted by the laser transmitter can be as thin as 0.125mm‌. The quality of the laser beam is usually expressed by the M2 factor. The smaller the M2 factor, the better the beam quality, the stronger the focusing ability, and the smaller the spot‌.

[0003] There are certain quality requirements for glass before it leaves the factory, so it is necessary to check whether there are scratches on the glass surface. The traditional detection method is manual detection, but the efficiency of manual detection is relatively low and it is no longer suitable for modern assembly line production. With the development of technology, the method of using machine vision for scratch detection is gradually being used by manufacturers;

[0004] However, since scratches are formed at various angles and directions, the scratch information in a certain direction or angle cannot be collected, and lighting at different angles is required. If full-angle fill light is used, the light in the target area will be too strong, and flare will appear to cover the scratch information. For this reason, we design a new device for detecting glass scratches to provide another method for detecting scratches.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0006] The purpose of the present invention is to design a new device and method for detecting glass scratches, which can detect scratches on the glass surface without the need for multi-angle lighting, so as to solve the above-mentioned deficiencies in the technology.

[0007] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions: a surface scratch detection device for optical glass, comprising a platform for mounting glass, and an XY-axis slide module mounted on the platform, the middle of the platform is designed to penetrate, the XY-axis slide module is set to two groups, which are respectively mounted above and below the platform, the heads on the two groups of XY-axis slide modules move synchronously and remain on the same vertical line, the bottom of the upper head is fixedly mounted with a laser transmitter and a laser receiver, and the top of the lower head is fixedly mounted with a reflector;

[0008] The laser is emitted by the laser transmitter and refracted on the upper surface of the glass. Then it is reflected from the inside of the glass to the surface of the reflector and refracted back to the lower surface of the glass. Finally, the laser passes through the upper surface of the glass and is received by the laser receiver. When there is a scratch at the point where the laser enters the glass surface, the laser receiver cannot receive the laser.

[0009] The XY-axis slide module adopts a magnetic suspension linear motor module with high precision.

[0010] Preferably, the surface of the reflector that reflects the laser light is configured as a mirror surface.

[0011] Preferably, the cross section of a surface of the reflector reflecting the laser light is arranged to be arc-shaped, and there is a gap between the top surface of the reflector and the glass.

[0012] Preferably, the reflector is configured to be cylindrical, the element line of the reflector is parallel to the horizontal plane, and the straight line formed by the laser transmitter and the laser receiver is perpendicular to the element line of the reflector.

[0013] Preferably, the reflector is configured as a strip, a cross section of one surface of the strip reflector is arc-shaped, the reflector is parallel to a horizontal plane, and a straight line formed by the laser emitter and the laser receiver is perpendicular to the reflector.

[0014] Preferably, the laser receiver is perpendicular to the glass, and there is an angle between the laser transmitter and the top surface of the glass. After the laser emitted by the laser receiver enters the glass from an entry point without scratches, the laser is reflected by the reflector and then vertically emitted from the glass upward to be received by the laser receiver.

[0015] Preferably, a nozzle is installed between the laser transmitter and the laser receiver, and the nozzle is perpendicular to the top of the laser injection point.

[0016] In a second aspect, the present invention further provides a detection method for operating the optical glass surface scratch detection device for detection, the method comprising the steps of:

[0017] S1: Place the glass on the platform and turn on the laser transmitter;

[0018] S2: Adjust the angle of the laser transmitter so that there are no scratches at the point where the laser emitted by the laser transmitter hits the glass, and ensure that the laser receiver can receive the laser emitted by the laser transmitter;

[0019] S3: Start two sets of XY-axis slide modules to drive the two heads to move on the platform, so that the laser emitted by the laser transmitter moves the incident point formed on the glass surface;

[0020] S4: When the laser cannot receive the laser emitted by the laser transmitter, the two sets of XY-axis slide modules stop moving, and the nozzles are started to spray the marking liquid downward to the laser entry point on the glass surface;

[0021] S5: The two sets of XY-axis slide modules continue to move at a constant speed, and steps S3 and S4 are repeated until the entire glass surface is inspected.

[0022] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0023] The present invention uses a laser transmitter to emit laser to the glass surface, and then the laser is refracted through the glass surface and emitted to the reflector, and then reflected by the reflector to the lower surface of the glass, and finally the laser is emitted from the upper surface of the glass. If the laser receiver receives the laser, it means that there is no scratch at the laser injection point, and if the laser receiver does not receive the laser, it means that there is a scratch at the laser injection point.

[0024] The present invention sets the laser receiver vertically and sets the laser transmitter at an angle accordingly. After taking into account the reflection angle of the reflector, it is ensured that when the laser emitted by the laser transmitter enters an entry point without a scratch, the reflected laser is vertically directed upward toward the laser receiver, thereby avoiding the problem of scratches at the laser exit point affecting the laser receiver's inability to receive the laser and causing misjudgment of the laser entry point having a scratch.

[0025] At the same time, the present invention sets the mirror surface of the reflector to be arc-shaped, so that when there is a scratch at the entrance point on the glass, the angle between the laser entrance and the laser exit increases compared to when there is no scratch at the entrance point on the glass, thereby preventing the laser receiver from mistakenly receiving the laser at the entrance point with a scratch;

[0026] Compared with the prior art which uses video to obtain pictures and then directly calculates the relevant parameters of all pixels for judgment to make quality judgment, the present invention provides a new method for glass scratching.

[0027] After detecting scratches on the glass surface, the present invention will spray marking liquid onto the scratches through a nozzle. Due to the different angles and directions of the scratches, some liquids do not fall accurately into the scratches, but exist in their immediate surroundings. However, it fully satisfies the need for manual rapid locating of the scratches and repairing them in the later stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 This is a schematic diagram of the first state of the injection point without scratches of the present invention;

[0031] Figure 3 This is a schematic diagram of the second state of the injection point without scratches of the present invention;

[0032] Figure 4 A schematic diagram of a tilted state of a laser receiver of the present invention;

[0033] Figure 5 This is a schematic diagram of a first state in which a scratch exists at the injection point of the present invention;

[0034] Figure 6 This is a schematic diagram of a second state in which a scratch exists at the injection point of the present invention;

[0035] Figure 7 This is a schematic diagram of the third state in which a scratch exists on the injection point of the present invention.

[0036] Description of reference numerals:

[0037] 1. Platform; 2. XY-axis slide module; 3. Machine head; 4. Laser transmitter; 5. Laser receiver; 6. Reflector; 7. Nozzle. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0040] The present invention provides Figure 1-7The optical glass surface scratch detection device shown in the figure comprises a platform 1 for mounting the glass, and an XY-axis slide module 2 mounted on the platform 1. The XY-axis slide module 2 is arranged in two groups, which are respectively mounted above and below the platform 1. The heads 3 on the two groups of XY-axis slide modules 2 move synchronously and are kept on the same vertical line. A laser transmitter 4 and a laser receiver 5 are fixedly mounted on the bottom of the upper head 3. A reflector 6 is fixedly mounted on the top of the lower head 3. When the reflector 6 is arranged in a cylindrical shape, the element line of the reflector 6 is parallel to the horizontal plane. The laser transmitter 4 and the laser receiver 5 are fixedly mounted on the bottom of the upper head 3. 4 and the laser receiver 5 are perpendicular to the element line of the reflector 6. The reflector 6 is arranged in a strip shape. When the cross section of one surface of the strip reflector 6 is arc-shaped, the reflector 6 is parallel to the horizontal plane, and the straight line formed by the laser emitter 4 and the laser receiver 5 is perpendicular to the reflector 6. The middle part of the platform 1 is designed to be through-type, so that the laser emitted by the laser emitter 4 can pass through the through-type part of the glass and the middle part of the platform 1, so that the laser can be reflected into the glass after being irradiated on the reflector 6, and then emitted from the glass from bottom to top; Figure 2 and Figure 3 As shown: During this period, we need to install the laser receiver 5 vertically and install the laser transmitter 4 tilted, so that there is a distance between the laser transmitter 4 and the laser transmitter 4. The tilt angle setting of the laser transmitter 4 needs to ensure that the laser emitted by the laser transmitter 4, after entering the glass surface, if there is no scratch at the laser entry point, then the laser is refracted by the glass and shot from the lower surface of the glass to the mirror surface of the reflector 6, and then reflected to vertically upward into the glass, and finally received by the vertical laser receiver 5. If the laser receiver 5 is set tilted, as shown in FIG. Figure 4 As shown in FIG. 1 , although there is no scratch at the laser entry point, there is a scratch at the laser exit point on the glass surface, which will cause the laser receiver 5 to fail to receive the emitted laser, resulting in a misjudgment. However, if the laser receiver 5 is installed vertically, then Figure 3 As shown, the laser is reflected vertically from the bottom to the top from the lower surface of the glass. Even if there is a scratch at the laser emission point, it still does not affect the scratch detection at the laser entry point. At the same time, we set the surface of the reflector 6 used to reflect the laser to be an arc shape, and this shape can be achieved by using a cylinder, such as Figure 3 , Figure 4 As shown, the cylindrical part that does not reflect the laser can also be removed, leaving only the long strip with an arc cross section, which can also achieve the same effect, such as Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7As shown, when the laser is shot from the scratch on the glass, due to the glass refractive index and the certain depth of the scratch, the exit point of the laser from the lower surface of the glass will be shifted relative to the case where the laser is shot from the entry point without a scratch, that is, there is a distance between the two exit points. Because we set the mirror surface of the reflector 6 to be arc-shaped, the scratch laser will no longer be shot vertically upward after being reflected by the surface of the reflector 6, but will be shot obliquely. Compared with the plane state of the reflector 6, the angle of the laser shot from the upper surface of the glass is enlarged, and in order to let the subsequent inspectors quickly know where the defects of the glass are, we install a nozzle 7 on the machine head 3, so that the nozzle 7 is located directly above the laser entry point, and after the scratch is detected, the marking liquid can be sprayed to mark the scratch;

[0041] In combination with a surface scratch detection device for optical glass, the present invention also provides a detection method for operating a surface scratch detection device for optical glass for detection, and the method comprises the steps of:

[0042] S1: Place the glass on the platform 1 and then turn on the laser transmitter 4;

[0043] S2: Adjust the angle of the laser transmitter 4 so that there is no scratch at the point where the laser emitted by the laser transmitter 4 hits the glass, and ensure that the laser receiver 5 can receive the laser emitted by the laser transmitter 4;

[0044] S3: Start the two sets of XY-axis slide modules 2 to drive the two heads 3 to move on the platform 1, so that the incident point formed by the laser emitted by the laser transmitter 4 on the glass surface moves;

[0045] S4: When the laser cannot receive the laser emitted by the laser emitter 4, the two sets of XY-axis slide table modules 2 stop moving, and the nozzle 7 is started to spray the marking liquid downward to the laser entry point on the glass surface;

[0046] S5: The two sets of XY-axis slide table modules 2 continue to move at a constant speed, and steps S3 and S4 are repeated until the entire glass surface is inspected.

[0047] It is important to note that the construction and arrangement of the present application shown in a number of different exemplary embodiments are exemplary only. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, colors, changes in orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application.

Claims

1. An optical glass surface scratch detection device, comprising a platform (1) for mounting glass, and an XY-axis slide table module (2) mounted on the platform (1), characterized in that: The platform (1) has a through-hole design in the middle, and the XY-axis slide table modules (2) are arranged in two groups, which are respectively installed above and below the platform (1). The heads (3) on the two groups of XY-axis slide table modules (2) move synchronously and remain on the same vertical line. A laser transmitter (4) and a laser receiver (5) are fixedly installed at the bottom of the upper head (3), and a reflector (6) is fixedly installed at the top of the lower head (3); The cross-section of one side of the reflector (6) that reflects the laser light is arranged to be arc-shaped, and there is a gap between the top surface of the reflector (6) and the glass; The laser receiver (5) is perpendicular to the glass, and an angle is formed between the laser transmitter (4) and the top surface of the glass. After the laser emitted by the laser receiver (5) enters the glass from an entry point without a scratch, the laser is reflected by the reflector (6) and then vertically emitted upward from the glass to be received by the laser receiver (5); The laser is emitted by the laser emitter (4) and directed to the upper surface of the glass, where it is refracted. The laser is then directed from the inside of the glass to the surface of the reflector (6), where it is reflected back to the lower surface of the glass, where it is refracted. Finally, the laser passes through the upper surface of the glass and is received by the laser receiver (5). When there is a scratch at the point where the laser is incident on the glass surface, the laser receiver (5) cannot receive the laser.

2. The optical glass surface scratch detection device according to claim 1, characterized in that: The surface of the reflector (6) that reflects laser light is configured as a mirror surface.

3. The optical glass surface scratch detection device according to claim 1, characterized in that: The reflector (6) is arranged in a cylindrical shape, the element line of the reflector (6) is parallel to the horizontal plane, and the straight line formed by the laser transmitter (4) and the laser receiver (5) is perpendicular to the element line of the reflector (6).

4. The optical glass surface scratch detection device according to claim 1, characterized in that: The reflector (6) is configured as a long strip, a cross section of one surface of the long strip reflector (6) is arc-shaped, the reflector (6) is parallel to a horizontal plane, and a straight line formed by the laser transmitter (4) and the laser receiver (5) is perpendicular to the reflector (6).

5. The optical glass surface scratch detection device according to claim 1, characterized in that: A nozzle (7) is installed between the laser transmitter (4) and the laser receiver (5), and the nozzle (7) is perpendicular to the top of the laser injection point.

6. A detection method for operating the optical glass surface scratch detection device according to any one of claims 1 to 5 for detection, characterized in that: The following steps are involved: S1: Place the glass on the platform (1), and then turn on the laser transmitter (4); S2: adjusting the angle of the laser transmitter (4) so ​​that there is no scratch at the point where the laser emitted by the laser transmitter (4) impinges on the glass, and ensuring that the laser receiver (5) can receive the laser emitted by the laser transmitter (4); S3: Start the two sets of XY-axis slide modules (2) to drive the two machine heads (3) to move on the platform (1), so that the incident point formed by the laser emitted by the laser transmitter (4) on the glass surface moves; S4: When the laser cannot receive the laser light emitted by the laser emitter (4), the two sets of XY-axis slide table modules (2) stop moving, and the nozzle (7) is started to spray the marking liquid downward to the laser entry point on the glass surface; S5: The two sets of XY-axis slide modules (2) continue to move at a constant speed, and steps S3 and S4 are repeated until the entire glass surface is inspected.

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