Flatness testing equipment, testing parts and flatness testing methods

Abstract

The present invention discloses a flatness detection device, a detection member and a flatness detection method. The flatness detection device is used to perform flatness detection on a surface to be tested, and includes an optical network device and a detection member. The optical network device is used to provide an optical network, and the optical network is composed of a plurality of interlaced light rays forming a mesh. The detection member includes at least a supporting portion and a shielding portion. The supporting portion is used to support the surface to be tested, and the shielding portion is used to be placed in the optical network. The shielding portion is constructed so that when the supporting portion is supported on positions with different flatness on the surface to be tested, the shielding portion effectively shields different amounts of light. The flatness detection device, the detection member and the flatness detection method of the present invention place the detection member in the optical network. The detection member actually shields different amounts of light in the optical network due to different heights of the detection position. The height of the detection position can be obtained by the amount of light in the optical network shielded. The flatness detection device has a simple structure, low preparation cost, and the flatness detection method is simple and easy to operate.

Description

Technical Field

[0001] The present invention relates to the technical field of screen quality detection, and in particular to a flatness detection device, a detection member and a flatness detection method. Background Art

[0002] Nowadays, with the development of science and technology, electronic products are becoming more and more popular, especially infrared touch devices. Infrared touch devices set infrared emitting lamps and infrared receiving receivers on the side of the screen, and then obtain the touch position when an object blocks some infrared rays.

[0003] In the prior art, on the one hand, in order to reduce costs and increase the competitiveness of infrared touch devices, the transmitting lamps and receivers are changed from the original round-head plug-in lamp beads to flat-head plug-in lamp beads or flat-head patch lamp beads, the transmitting power of the lamp tube is reduced, and the position of the lamp tube in the lamp bead is closer to the glass; on the other hand, the thickness of the glass is getting thinner and thinner, and the thinner the glass is, the easier it is to deform during installation and use. Large-sized ultra-thin glass will also be deformed due to transportation and bumps when installed on the equipment. For this reason, when installing the glass, the glass is directly squeezed so that the glass is concave in the installed state, thereby reducing the deformation of the glass and improving the touch experience.

[0004] In the prior art, on the one hand, there is no flatness test on the flatness of the glass, but the glass is directly installed on the equipment. Since the lamp beads are very close to the glass, once the light is blocked due to the flatness of the glass itself, unqualified products will be caused, and the probability of unqualified products will not be directly reduced from the source of the raw materials; on the other hand, for the concavely installed glass, the prior art does not have the equipment to perform flatness tests on the concave glass. Once the concave degree of the glass is not within a reasonable range, qualified products will become unqualified during the subsequent use process such as bumps and transportation, thereby reducing the user experience. Summary of the invention

[0005] Based on the above situation, the main purpose of the present invention is to provide a flatness detection device, a detection member and a flatness detection method to solve the problem that the prior art lacks a device for flatness detection of raw materials and finished products of electronic screens.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A flatness detection device is used to perform flatness detection on a surface to be tested, comprising an optical network device and a detection member, wherein the optical network device is used to provide an optical network, wherein the optical network is formed into a mesh by a plurality of interlaced light rays, and the detection member comprises at least a supporting portion and a shielding portion, wherein the supporting portion is used to support the surface to be tested, and the shielding portion is used to be placed in the optical network, and the shielding portion is constructed such that when the supporting portion supports positions of the surface to be tested with different flatness, the shielding portion effectively blocks different amounts of the light rays.

[0008] Preferably, the optical network is a crisscrossed straight-scan optical network or a fan-shaped optical network.

[0009] Preferably, the detection member comprises a conical structure, the side surface of the conical structure constitutes the shielding portion, and the end surface of the large end of the conical structure constitutes the abutting portion.

[0010] Preferably, it also comprises a handle for easy holding, wherein the handle is connected to the small end of the tapered structure.

[0011] Preferably, the handle comprises a rod-shaped handle portion and a protruding portion, wherein the protruding portion is arranged along the circumference of the handle portion and the protruding direction forms an angle with the extending direction of the handle portion, and the protruding portion is used to indicate the extreme position of holding.

[0012] Preferably, the surface to be measured includes a plurality of detection positions, and the density of the optical network at each detection position is consistent.

[0013] To achieve the above purpose, the present invention also adopts the following technical solutions:

[0014] A detection component is used to detect the flatness of glass in an infrared touch display screen, the infrared touch display screen can form an infrared light network, the detection component includes a supporting portion and a shielding portion, the supporting portion is used to support the glass surface, the shielding portion is used to be placed in the infrared light network, the infrared light network is formed by a plurality of staggered infrared light rays forming a mesh, and the shielding portion is constructed so that when the supporting portion is against positions with different flatness on the surface to be tested, the shielding portion effectively blocks different amounts of the infrared light.

[0015] Preferably, the detection member comprises a conical structure, the side surface of the conical structure constitutes the shielding portion, and the end surface of the large end of the conical structure constitutes the abutting portion.

[0016] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0017] A flatness detection method is used to perform flatness detection on a surface to be detected, and an optical net and a detection member are provided. The optical net is formed of a plurality of interlaced light rays in a net shape. The detection member at least comprises a supporting portion and a shielding portion. The supporting portion is used to support the surface to be detected, and the shielding portion is used to be placed in the optical net. The shielding portion is configured such that when the supporting portion is supported on positions of the surface to be detected with different flatness, the shielding portion effectively shields different amounts of the light rays.

[0018] The method comprises the following steps:

[0019] S1: placing the surface to be measured on one side of the optical network;

[0020] S2: placing the shielding portion in the optical network, and placing the abutting portion at a detection position of the surface to be measured;

[0021] S3: Acquire the number of light rays of the optical network blocked by the blocking portion at the detection position;

[0022] S4: Obtain the flatness of the surface to be measured according to the number of light rays obtained in step S3.

[0023] Preferably, the detection member comprises a conical structure, the side surface of the conical structure constitutes the shielding portion, and the end surface of the large end of the conical structure constitutes the abutting portion;

[0024] The step S4 specifically includes:

[0025] S41: according to the number of light rays obtained in step S3, obtaining the distance between the position where the shielding portion shields the light rays at the detection position and the cone top;

[0026] S42: Obtain the height of the detection position according to the distance from the position where the shielding portion shields the light to the cone top obtained in step S41;

[0027] S43: Obtain the flatness of the surface to be measured according to the heights of the multiple detection positions obtained in step S42.

[0028] Preferably, in step S41, the distance H2 between the position where the shielding portion shields the light and the cone top is specifically calculated by the following formula:

[0029] H2=H1*[(N1 / N2)1 / 2];

[0030] Among them, H1 is the actual height of the large end from the cone top; N1 is the number of light rays of the optical network that can actually be blocked by the large end; and N2 is the number of light rays of the optical network that can actually be blocked by the position where the shielding part blocks the light.

[0031] Preferably, the method further comprises step S5 after step S3 and before step S4:

[0032] Step S5: Determine whether the light quantity N2 obtained in step S3 is greater than N1, if so, execute S4, if so, exit.

[0033] Preferably, the outer contour of the surface to be measured is a rectangle, and the distance between the detection position and a side of the rectangle is greater than or equal to one quarter of the distance between the side and the side opposite to the side.

[0034] Preferably, the flatness detection method uses the above-mentioned flatness detection device or the detection piece is the above-mentioned detection piece.

[0035] The flatness detection equipment, detection part and flatness detection method of the present invention place the detection part in the optical network. The detection part has different effective areas that actually block the light in the optical network due to different heights of the detection position, which leads to different numbers of light actually blocked in the optical network. The height of the detection position can be obtained by the number of light in the optical network blocked. The flatness detection equipment has a simple structure and low preparation cost. The flatness detection method is simple and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Hereinafter, preferred embodiments of the flatness detection device, the detection member and the flatness detection method according to the present invention will be described with reference to the accompanying drawings.

[0037] Figure 1 A schematic structural diagram of a detection element according to a preferred embodiment of the present invention;

[0038] Figure 2 A test principle diagram of a flatness detection method according to a preferred embodiment of the present invention;

[0039] Figure 3 For Figure 2 The corresponding top view;

[0040] Figure 4 For Figure 2 The corresponding schematic diagram of the calculation principle;

[0041] Figure 5 A schematic structural diagram of a fan-shaped optical network formed by an optical network device according to a preferred embodiment of the present invention;

[0042] Figure 6 It is a schematic structural diagram of the detection position according to a preferred embodiment of the present invention.

[0043] In the figure:

[0044] 1. Detection position 1;

[0045] 2. Detection member; 21. Shielding portion; 22. Handle; 221. Handle portion; 222. Protruding portion; 23. Abutting portion;

[0046] 3. Detection position 2;

[0047] 4. Optical network;

[0048] 5. Surface to be tested. DETAILED DESCRIPTION

[0049] In view of the problem that there is no equipment for flatness detection of raw materials and finished products of electronic screens in the prior art, the present invention provides a flatness detection equipment.

[0050] The flatness detection device of the present invention is used to detect the flatness of the surface to be tested of the test piece, for example, to detect the flatness of the glass surface, and for another example, to detect the flatness of the screen surface. In other words, the flatness test can be performed on the glass before the glass is assembled on the electronic product, and the flatness test can also be performed on the screen formed by the glass after the glass is assembled on the electronic product.

[0051] The flatness detection device includes an optical network device and a detection member 2, such as Figure 1 As shown, the optical network device is used to provide an optical network 4, such as Figure 3 As shown, the optical network 4 is formed into a network by a plurality of interlaced light rays, and the plurality of light rays can be formed by emitting light from a plurality of lamp beads, and the light rays formed by the light emission from the lamp beads can be any light rays, for example, infrared rays.

[0052] The detection member 2 at least includes a supporting portion 23 and a shielding portion 21. Figure 2 As shown, the device to be tested is placed on one side of the optical network 4, and the surface to be tested 5 of the device to be tested faces the side of the optical network, the abutting portion 23 is used to abut on the surface to be tested 5, and the shielding portion 21 is used to be placed in the optical network 4. The shielding portion 21 is constructed so that when the abutting portion 23 abuts on the position of the surface to be tested 5 with different flatness, the shielding portion 21 effectively blocks different amounts of light. The flatness of the surface to be tested 5 of the device to be tested is calculated by the effective amount of light blocked by the shielding portion 21. Preferably, the optical network 4 is a criss-crossed straight scanning optical network or a fan-shaped optical network.

[0053] The detection member 2 includes a conical structure, and the side surface of the conical structure constitutes the shielding portion 21. Figure 2As shown, the end face of the large end of the conical structure constitutes the abutment portion 23, and the conical structure can be a solid structure or a hollow structure. The conical structure is made of opaque material, so that the test result of the flatness detection equipment can be more accurate than that of semi-transparent material. Preferably, the conical structure is a conical shape. When the shielding portion 21 is placed in the optical network 4, different actual shielding positions can block different amounts of light, and the actual shielding position refers to the position where the shielding portion 21 actually blocks the light.

[0054] The detection member 2 also includes a handle 22 for easy holding. Figure 1 As shown, the handle 22 is connected to the small end of the conical structure, and the handle 22 is used to operate the detection member 2. Preferably, the handle 22 includes a rod-shaped handle portion 221 and a protruding portion 222, such as Figure 1 As shown, the protrusion 222 is arranged along the circumference of the handle portion 221 and the protruding direction is arranged at an angle to the extension direction of the handle portion 221. Preferably, there is a gap between the protrusion 222 and the shielding portion 21. More preferably, the protrusion 222 is arranged along the entire circumference of the handle portion 221. The protrusion 222 is used to mark the extreme position of holding to avoid contact between the hand and the shielding portion 21. The setting of the protrusion 222 improves the accuracy of user operation and reduces test errors.

[0055] The surface to be measured 5 includes a plurality of detection positions, and the density of the optical network at each detection position is consistent, so that it is more convenient and simple to calculate the flatness of the surface to be measured by the detection member 2.

[0056] The present invention also provides a detection component 2 for detecting the flatness of glass in an infrared touch display screen. Since the infrared touch display screen itself can form an infrared light network, no additional device is required to provide the infrared light network. Only the detection component is required to detect the flatness of the glass in the infrared touch display screen. The detection component 2 includes a supporting portion 23 and a shielding portion 21. The supporting portion 23 is used to support the glass surface, and the shielding portion 21 is used to be placed in the infrared light network formed by the infrared touch display screen itself. The infrared light network is formed of a plurality of interlaced infrared light rays in a mesh shape. The shielding portion 21 is constructed so that when the supporting portion 23 is supported on positions with different flatness on the surface to be tested, the shielding portion 21 effectively blocks different amounts of the infrared light.

[0057] The detection member 2 includes a conical structure, the side surface of the conical structure constitutes the shielding portion 21, and the end surface of the large end of the conical structure constitutes the abutting portion 23.

[0058] The present invention also provides a flatness detection method for detecting the flatness of a surface to be detected, providing an optical network 4 (the optical network 4 here can be provided by the object to be detected itself, or can be provided by another device) and a detection member 2, wherein the optical network 4 is formed of a plurality of interlaced light rays in a mesh shape, and the detection member 2 at least includes a support portion 23 and a shielding portion 21, wherein the support portion 23 is used to support the surface to be detected, and the shielding portion 21 is used to be placed in the optical network 4, and the shielding portion 21 is constructed such that when the support portion 23 is supported on positions of the surface to be detected with different flatness, the shielding portion 21 effectively shields different amounts of the light rays. Specifically, the method comprises the following steps:

[0059] S1: placing the surface 5 to be measured on one side of the optical network 4;

[0060] S2: placing the shielding portion 21 in the optical network 4, and placing the abutting portion 23 at the detection position of the surface to be measured 5;

[0061] S3: Acquire the number of light rays of the optical network 4 blocked by the blocking portion 21 at the detection position;

[0062] S4: Obtain the flatness of the surface 5 to be measured according to the number of light rays obtained in step S3.

[0063] Preferably, the step S4 specifically includes:

[0064] S41: according to the amount of light obtained in step S3, obtaining the distance from the position where the shielding portion 21 shields the light at the detection position to the cone top;

[0065] S42: Obtain the height of the detection position according to the distance from the position where the shielding portion 21 shields the light obtained in step S41 to the cone top;

[0066] S43: Obtain the flatness of the surface 5 to be measured according to the heights of the plurality of detection positions obtained in step S42.

[0067] In the present invention, in step S41, the distance H2 between the position where the shielding portion 21 shields the light and the cone top is specifically calculated by the following formula:

[0068] H2=H1*[(N1 / N2)1 / 2];

[0069] Among them, H1 is the actual height of the large end from the cone top; N1 is the number of light rays of the optical network 4 that the large end can actually block; N2 is the number of light rays of the optical network 4 that the blocking portion 21 can actually block at its blocking position.

[0070] The flatness detection method further includes step S5 located after step S3 and before step S4:

[0071] Step S5: Determine whether the light quantity N2 obtained in step S3 is greater than N1, if less, execute N4, if greater, exit.

[0072] When the light quantity N2 obtained in the step S3 is greater than N1, it means that an area of ​​the surface 5 to be tested blocks the light. If the piece to be tested is not installed on the product, the flatness test is performed after readjustment. If the piece to be tested is installed on the product, there is a problem with the product. The piece to be tested is directly shaped by installing the profile of the piece to be tested, and the flatness test is performed again after the shaping.

[0073] The optical network 4 may be a straight-scan optical network, such as Figure 3 and Figure 6 As shown, or, it can be a fan-shaped optical network, such as Figure 5 As shown, however, it is required that the density of the optical network 4 at multiple detection positions is consistent. In other words, the number of light rays of the optical network 4 is consistent within a certain area at multiple detection positions. In this way, it is more convenient and accurate to calculate the flatness of the surface 5 to be measured based on the number of light rays blocked by the blocking portion 21.

[0074] In the flatness detection method of the present invention, the test piece includes the glass to be tested and the screen of the electronic product to be tested. When the screen of the electronic product to be tested is tested, the selection of the detection position should avoid being close to the edge of the screen. Preferably, when the outer contour of the surface to be tested 5 is a rectangle, the distance between the detection position and one side of the rectangle is greater than or equal to one quarter of the distance between the one side and the side opposite to the one side. Figure 6 As shown, this is because when installing the screen, in order to avoid deformation of the screen and reduce the touch accuracy, the screen will be installed in a slightly concave state. When the screen is installed, the position near the edge of the screen is almost flat. Testing the flatness at the position near the edge cannot truly reflect the flatness of the screen, and the test error is large. Further preferably, multiple detection positions are arranged symmetrically.

[0075] In a specific embodiment, when the outer contour of the surface to be measured 5 is a rectangle, the number of the detection positions is five, one of which is the middle position of the rectangle, and each of the remaining four detection positions is selected such that the distance between each detection position and each of the two adjacent intersecting sides is respectively one-fourth of the distance between the side and the side opposite to the side, such as Figure 6As shown, specifically, taking the straight scanning optical network as an example, five detection positions are selected by adopting the detection position selection method given in the above specific implementation mode, and the screen of the electronic product with a rectangular outer contour is tested. The test process is as follows:

[0076] Step 1: Select five detection locations;

[0077] Step 2: placing the detection member 2 at the five detection positions selected in the first step respectively;

[0078] Step 3: Use the heights of the five detection positions to get the flatness of the screen.

[0079] In order to explain the test principle simply and clearly, the following only takes the test position 1 and the test position 2 as examples to give the test principle:

[0080] 1. The whole screen is concave, and no part of the screen blocks any light from the optical network 4, such as Figure 2 As shown, the flatness of the detection position 1 and the detection position 2 3 is different, and the degree of concavity of the detection position 1 is greater than that of the detection position 2 3.

[0081] 2. When the detection member 2 is placed at the detection position 1 and the detection position 2 3, the actual blocking position of the blocking portion 21 blocking the light net 4 is different, such as Figure 3 As shown, at the detection position 23, the shielding portion 21 shields a large amount of light from the light network 4.

[0082] 3. After the optical network 4 and the detection member 2 are fixed, the actual shielding position of the detection member 2 changes with the actual height of the surface to be measured. The number N of light rays in the optical network 4 blocked by the shielding portion 21 at the determined shielding position is fixed (N is related to the density of the optical network), the large end position corresponds to the cross-sectional area S1 and the number N1 of light rays of the optical network 4 blocked by the large end position is known, the distance H1 from the large end of the shielding portion 21 to the top of the cone is known, the actual shielding position corresponds to the cross-sectional area S2 and the number N2 of light rays of the optical network 4 blocked by the actual shielding position is known, and the distance H2 from the actual shielding position to the top of the cone is an unknown quantity. There is a corresponding relationship of N1 / N2=S1 / S2=(H1*H1) / (H2*H2), such as Figure 4 As shown, we can obtain: H2 = H1*[(N1 / N2)1 / 2].

[0083] 4. The height h of the detection position can be obtained according to the distance H2 from the actual blocking position to the top of the cone. The height h of the detection position is the theoretical height H0 of the optical network 4 from the screen minus the difference between H1 and H2, that is, h=H0-(H1-H2).

[0084] 5. Use the height h of the five detection positions to obtain the flatness of the screen.

[0085] It is worth noting that when the optical network 4 is not a straight-scan optical network, the selection of the detection position can be the method given in the above-mentioned embodiment, or other selection methods. When the number of light rays per unit area at the detection position is basically the same, that is, the density of the optical network 4 is consistent, the flatness test method can be made simpler. For ease of operation, the selection of the detection position can be achieved through software. When actually testing the flatness, it is only necessary to place the detection member 2 in the approximate area. The size of the detection member 2 can be determined according to the actual situation, depending on the density of the optical network 4. The denser the optical network 4, the larger the size of the large end, and the higher the test accuracy of the flatness. Of course, the size of the large end cannot be too large. When actually testing the flatness of the screen, the number of light rays that the detection member 2 can block from the optical network 4 is between dozens or hundreds. The optical network 4 is very large, and more detection positions can be selected, such as six, nine, etc., so that a more accurate flatness can be obtained.

[0086] The flatness detection method of the present invention can evaluate the initial flatness of the glass to prevent the incoming glass from being defective, which may cause the finished product to be disassembled and repaired due to the defective glass. It can also evaluate the flatness of the screen after the glass is assembled and the touch performance margin. It can screen out defective products or critical products at the production end to prevent the screen from being deformed due to insufficient margin of the whole machine and bumps during transportation, thereby reducing the touch performance of the whole machine and causing after-sales repairs.

[0087] Those skilled in the art will appreciate that, without conflict, the above-mentioned preferred solutions can be freely combined and superimposed.

[0088] It should be understood that the above-mentioned embodiments are merely illustrative and not restrictive. Without departing from the basic principles of the present invention, various obvious or equivalent modifications or substitutions that can be made by those skilled in the art to the above-mentioned details will all be included in the scope of the claims of the present invention.

Claims

1. A flatness detection device, used for detecting the flatness of a surface to be detected, characterized in that: The invention comprises an optical network device and a detection member, wherein the optical network device is used to provide an optical network, wherein the optical network is formed into a mesh by a plurality of interlaced light rays, and the detection member comprises at least a supporting portion and a shielding portion, wherein the supporting portion is used to support the surface to be tested, and the shielding portion is used to be placed in the optical network, and the shielding portion is constructed so that when the supporting portion supports positions with different flatness on the surface to be tested, the shielding portion effectively shields different amounts of the light rays.

2. The flatness detection device according to claim 1, characterized in that: The optical network is a crisscrossed straight-scan optical network or a fan-shaped optical network.

3. The flatness detection device according to claim 1, characterized in that: The detection member comprises a conical structure, the side surface of the conical structure constitutes the shielding portion, and the end surface of the large end of the conical structure constitutes the abutting portion.

4. The flatness detection device according to claim 3, characterized in that: The utility model also comprises a handle for easy holding, wherein the handle is connected to the small end of the conical structure.

5. The flatness detection device according to claim 4, characterized in that: The handle comprises a rod-shaped handle portion and a protruding portion, wherein the protruding portion is arranged along the circumference of the handle portion and the protruding direction forms an angle with the extending direction of the handle portion, and the protruding portion is used to mark the extreme position of holding.

6. The flatness detection device according to any one of claims 1 to 5, characterized in that: The surface to be measured includes a plurality of detection positions, and the density of the optical network at each detection position is consistent.

7. A detection component for detecting the flatness of glass in an infrared touch display screen, wherein the infrared touch display screen can form an infrared light network, characterized in that: The detection member includes a supporting portion and a shielding portion, the supporting portion is used to support the glass surface, the shielding portion is used to be placed in the infrared light network, the infrared light network is composed of a plurality of staggered infrared light rays forming a mesh, and the shielding portion is constructed so that when the supporting portion is against positions with different flatness of the surface to be tested, the shielding portion effectively blocks different amounts of the infrared light.

8. The detection element according to claim 7, characterized in that: The detection member comprises a conical structure, the side surface of the conical structure constitutes the shielding portion, and the end surface of the large end of the conical structure constitutes the abutting portion.

9. A flatness detection method for detecting the flatness of a surface to be detected, characterized in that: Provided are an optical net and a detection member, wherein the optical net is formed into a net shape by a plurality of interlaced light rays, the detection member at least comprises a supporting portion and a shielding portion, the supporting portion is used to support the surface to be tested, the shielding portion is used to be placed in the optical net, and the shielding portion is constructed such that when the supporting portion supports positions of the surface to be tested with different flatnesses, the shielding portion effectively shields different amounts of the light rays; the detection member comprises a conical structure, the side surface of the conical structure constitutes the shielding portion, and the end surface of the large end of the conical structure constitutes the supporting portion; The method comprises the following steps: S1: placing the surface to be measured on one side of the optical network; S2: placing the shielding portion in the optical network, and placing the abutting portion at a detection position of the surface to be measured; S3: Acquire the number of light rays of the optical network blocked by the blocking portion at the detection position; S4: Obtaining the flatness of the surface to be measured according to the number of light rays obtained in step S3; The step S4 specifically includes: S41: according to the number of light rays obtained in step S3, obtaining the distance between the position where the shielding portion shields the light rays at the detection position and the cone top; S42: Obtain the height of the detection position according to the distance from the position where the shielding portion shields the light to the cone top obtained in step S41; S43: Obtain the flatness of the surface to be measured according to the heights of the multiple detection positions obtained in step S42.

10. The flatness detection method according to claim 9, characterized in that: In step S41, the distance H2 between the position where the shielding portion shields the light and the cone top is specifically calculated by the following formula: H2=H1*[(N1 / N2) 1 / 2 ]; Among them, H1 is the actual height of the large end from the cone top; N1 is the number of light rays of the optical network that can actually be blocked by the large end; and N2 is the number of light rays of the optical network that can actually be blocked by the position where the shielding part blocks the light.

11. The flatness detection method according to claim 9, characterized in that: The method further comprises step S5 after step S3 and before step S4: Step S5: Determine whether the light quantity N2 obtained in step S3 is greater than N1, if so, execute S4, if so, exit.

12. The flatness detection method according to any one of claims 9 to 11, characterized in that: The outer contour of the surface to be measured is a rectangle, and the distance between the detection position and one side of the rectangle is greater than or equal to one quarter of the distance between the one side and another side opposite to the one side.

13. The flatness detection method according to any one of claims 9 to 11, characterized in that: The flatness detection method uses the flatness detection device described in any one of claims 1 to 6, or the detection piece is the detection piece described in claim 7 or 8.

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