Automatic focusing device of high-precision projection exposure machine

Abstract

The utility model provides an automatic focusing device of a high-precision projection exposure machine. The automatic focusing device comprises a projection module, a light splitting module, an electric displacement platform, an image detector and a main control module, the light splitting module divides a focusing projection image emitted by the projection module into a first image and a second image with the same definition; the image detector is located on a propagation path of the first image, the to-be-projected target surface is located on a propagation path of the second image, and the image acquisition port is used for receiving the first image acquired by the image detector; when the definition of the first image does not meet the preset definition requirement, the distance control port controls the electric displacement platform to drive the projection module to move in the first direction until the precision of the first image meets the preset definition requirement; according to the technical scheme, the focal length is adjusted by focusing the definition of the projected image, the adjusting precision is improved while the adjusting system is simplified, and meanwhile, the light splitting module is utilized to separate one path of the projected image for research, so that the operation is more convenient.

Description

Technical Field

[0001] The embodiment of the utility model relates to the technical field of automatic focusing, and in particular to an automatic focusing device for a high-precision projection exposure machine. Background Art

[0002] How to clearly present the image of the projection exposure machine in front of people is the basis for its performance. The acquisition of clear images is the basis for further processing and analysis of the image, which will directly affect the accuracy of the entire exposure writing system. There are many factors that restrict the clarity of imaging, such as noise interference from lighting conditions, geometric shape and distortion of the scene, physical properties of the surface, and properties of the projection exposure lens, etc. Whether the image is correctly focused is the cornerstone of the normal operation of the system.

[0003] So far, the methods for achieving focus of the projected image can be divided into active and passive methods. The active focusing method can be simply described as calculating the focus position based on the system imaging principle, and using a distance measuring device to determine the location of the CMOS. The system first accurately calculates the relationship between the various distances of the focus position, and then continuously adjusts the relative positions of the workpiece, CMOS, and lens, and uses various distance measuring sensors to measure the distance. The passive focusing method based on machine vision is a focusing process based on the criterion of image clarity. After the system collects the image data, the computer performs relevant and effective evaluation calculations on the image, and finally controls the operation of the motor based on the results and search algorithm to achieve process regulation of the entire system.

[0004] Both of the above-mentioned focusing methods have corresponding disadvantages. For example, the peripheral hardware such as the active focusing technology rack often has systematic errors, such as manufacturing and installation errors, which will affect the accuracy of the distance measurement. If the workpiece has a strong absorption effect on infrared light or ultrasound, the measurement system will not focus accurately. The distance measurement method does not provide an image clarity criterion to evaluate whether the focusing result is satisfactory to address these shortcomings. Passive focusing relies on complex algorithms and precise feedback adjustment systems. The system is relatively complex and difficult to use. Utility Model Content

[0005] The utility model provides an automatic focusing device for a high-precision projection exposure machine, which improves the focusing accuracy and simplifies the device structure.

[0006] In a first aspect, an embodiment of the utility model provides an automatic focusing device for a high-precision projection exposure machine, including a projection module, a light splitting module, an electric displacement platform, an image detector, and a main control module;

[0007] The projection module is fixed on the displacement platform, the spectroscopic module is located on the light output path of the projection module, and divides the focused projection image emitted by the projection module into a first image and a second image with the same clarity; the image detector is located on the propagation path of the first image, the target surface to be projected is located on the propagation path of the second image, and the distance between the target surface to be projected and the spectroscopic module is equal to the distance between the image detector and the spectroscopic module;

[0008] The main control module includes an image acquisition port and a distance control port. The image acquisition port is electrically connected to the image detector and is used to receive the first image collected by the image detector. The distance control port is electrically connected to the electric displacement platform. When the clarity of the first image does not meet the preset clarity requirement, the electric displacement platform is controlled to drive the projection module to move along a first direction until the accuracy of the first image meets the preset clarity requirement. The first direction is the light emitting direction of the projection module.

[0009] Optionally, the focused projection image is a two-dimensional code image with a resolution of 1920*1080 and a single pixel size of 10um.

[0010] Optionally, the projection module includes an optical machine and a lens.

[0011] Optionally, the lens is a telecentric lens.

[0012] Optionally, the wavelength range of the light source of the optical machine is 510nm-530nm.

[0013] Optionally, the main control module further includes a first brightness control port, which is electrically connected to the optomechanical device, and adjusts the intensity of the light output by the optomechanical device when the brightness of the first image does not meet a preset brightness requirement.

[0014] Optionally, the main control module further includes a second brightness control port, which is connected to the image detector and controls the exposure time of the image detector when the brightness of the first image does not meet a preset brightness requirement.

[0015] Optionally, the stroke of the electric displacement platform is 0-30nm.

[0016] Optionally, the electric displacement platform has an accuracy of 1.5 um.

[0017] Optionally, the light splitting module is a semi-transparent and semi-reflective mirror, and the transmission and reflection ratio of the semi-transparent and semi-reflective mirror is 50:50;

[0018] The image detector is located on the light transmission path of the semi-transparent and semi-reflective mirror, and the target surface to be projected is located on the light reflection path of the semi-transparent and semi-reflective mirror.

[0019] The utility model provides an automatic focusing device for a high-precision projection exposure machine, comprising a projection module, a spectroscopic module, an electric displacement platform, an image detector and a main control module; the projection module is fixed on the displacement platform, the spectroscopic module is located on the light output path of the projection module, and divides the focused projection image emitted by the projection module into a first image and a second image with the same clarity; the image detector is located on the propagation path of the first image, the target surface to be projected is located on the propagation path of the second image, and the distance between the target surface to be projected and the spectroscopic module is equal to the distance between the image detector and the spectroscopic module; the main control module comprises an image acquisition port and a distance control port, the image acquisition port is electrically connected to the image detector and is used to receive the first image collected by the image detector; the distance control port is electrically connected to the electric displacement platform, and when the clarity of the first image does not meet the preset clarity requirement, the electric displacement platform is controlled to drive the projection module to move along the first direction until the accuracy of the first image meets the preset clarity requirement; the first direction is the light output direction of the projection module; the above technical scheme adjusts the focal length by adjusting the clarity of the focused projection image, simplifies the adjustment system and increases the adjustment accuracy, and at the same time uses the spectroscopic module to separate the projection picture into one path for research, so that the operation is more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the principle of an automatic focusing device for a high-precision projection exposure machine provided by an embodiment of the utility model;

[0021] Figure 2 This is a schematic structural diagram of an automatic focusing device for a high-precision projection exposure machine provided by an embodiment of the utility model;

[0022] Figure 3 It is a schematic diagram of a focusing projection image provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0024] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. It should be noted that the directional words such as "upper", "lower", "left", "right" and the like described in the embodiments of the present invention are described at the angles shown in the accompanying drawings and should not be understood as limitations on the embodiments of the present invention. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is formed "on" or "under" another element, it can not only be directly formed "on" or "under" another element, but also indirectly formed "on" or "under" another element through an intermediate element. The terms "first", "second" and the like are only used for descriptive purposes and do not represent any order, quantity or importance, but are only used to distinguish different components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances.

[0025] The term "including" and its variations used in the present invention are open inclusions, that is, "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment".

[0026] It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish the corresponding contents, and are not used to limit the order or interdependence.

[0027] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0028] Figure 1 This is a schematic diagram of the principle of an automatic focusing device for a high-precision projection exposure machine provided by an embodiment of the utility model. Figure 2 This is a schematic diagram of the structure of an automatic focusing device for a high-precision projection exposure machine provided by an embodiment of the utility model; Figure 1 , Figure 2The device includes a projection module 10, a spectroscopic module 20, an electric displacement platform 30, an image detector 40 and a main control module 50; the projection module 10 is fixed on the electric displacement platform 30, the spectroscopic module 20 is located on the light output path of the projection module 10, and divides the focused projection image emitted by the projection module 10 into a first image and a second image with the same clarity; the image detector 40 is located on the propagation path of the first image, the target surface 60 to be projected is located on the propagation path of the second image, and the distance between the target surface 60 to be projected and the spectroscopic module 20 and the image detector 40 is The distance between the main control module 50 and the spectroscopic module 20 is equal; the main control module 50 includes an image acquisition port 51 and a distance control port 52, the image acquisition port 51 is electrically connected to the image detector 40, and is used to receive the first image captured by the image detector 40; the distance control port 52 is electrically connected to the electric displacement platform 30, when the clarity of the first image does not meet the preset clarity requirement, the electric displacement platform 30 is controlled to drive the projection module 10 to move along the first direction x until the accuracy of the first image meets the preset clarity requirement; the first direction x is the light emitting direction of the projection module 10.

[0029] Specifically, refer to Figure 1 , Figure 2 In order to ensure that the image projected by the projection module 10 onto the target surface 60 to be projected is clear enough, thereby ensuring the viewing experience of the user; therefore, a spectroscopic module 20 is provided, and the spectroscopic module 20 is used to divide the focused projection image of the projection module 10 into a first image and a second image with the same clarity; the second image is projected onto the target surface 60 to be projected, and the first image is projected onto the image detector 40, and the distance between the target surface 60 to be projected and the spectroscopic module 20 is equal to the distance between the image detector 40 and the spectroscopic module 20, thereby ensuring that the first image and the second image formed after the focused projection image is split by the spectroscopic module 20 have the same size and clarity, and the main control module 50 is used to communicate The image information of the first image is acquired from the image detector 40 through the image acquisition port 51, and the clarity of the first image is determined. When the clarity of the first image does not meet the preset clarity requirement, the clarity of the second image on the surface, that is, the image projected onto the target surface 60 to be projected, also does not meet the preset clarity requirement. Therefore, it is necessary to adjust the distance between the projection module 10 and the projection target surface 60 and the image detector 40. Therefore, the electric displacement platform 30 is controlled through the distance control port 52 to drive the projection module 10 to move along the first direction until the accuracy of the first image meets the preset clarity requirement, and accordingly, the accuracy of the second image also meets the preset clarity requirement.

[0030] The utility model provides an automatic focusing device for a high-precision projection exposure machine, comprising a projection module, a spectroscopic module, an electric displacement platform, an image detector and a main control module; the projection module is fixed on the displacement platform, the spectroscopic module is located on the light output path of the projection module, and divides the focused projection image emitted by the projection module into a first image and a second image with the same clarity; the image detector is located on the propagation path of the first image, the target surface to be projected is located on the propagation path of the second image, and the distance between the target surface to be projected and the spectroscopic module is equal to the distance between the image detector and the spectroscopic module; the main control module comprises an image acquisition port and a distance control port, the image acquisition port is electrically connected to the image detector and is used to receive the first image collected by the image detector; the distance control port is electrically connected to the electric displacement platform, and when the clarity of the first image does not meet the preset clarity requirement, the electric displacement platform is controlled to drive the projection module to move along the first direction until the accuracy of the first image meets the preset clarity requirement; the first direction is the light output direction of the projection module; the above technical scheme adjusts the focal length by adjusting the clarity of the focused projection image, simplifies the adjustment system and increases the adjustment accuracy, and at the same time uses the spectroscopic module to separate the projection picture into one path for research, so that the operation is more convenient.

[0031] Optionally, Figure 3 is a schematic diagram of a focus projection image provided by an embodiment of the utility model, referring to Figure 3 The focused projection image is a two-dimensional code image with a resolution of 1920*1080 and a single pixel size of 10um. It adopts a high-density four-color level two-dimensional code. After being transmitted to the image detector 40, due to the high resolution of the two-dimensional code image, the corresponding main control module 50 obtains the two-dimensional code image, and the accuracy and efficiency of judging the clarity are also high, thereby controlling the electric displacement platform 30 to drive the projection module 10 to move with high accuracy.

[0032] The projection module 10 includes an optical machine and a lens. The lens adopts a telecentric lens, which has the advantages of high image resolution and low distortion, thereby further improving the focusing accuracy. The wavelength range of the light source of the optical machine is 510nm-530nm.

[0033] Optionally, the main control module 50 further includes a first brightness control port 53, which is electrically connected to the optomechanical device, and adjusts the intensity of the light output by the optomechanical device when the brightness of the first image does not meet a preset brightness requirement.

[0034] The preset brightness requirement may be understood as a preset requirement based on the image clarity recognition capability of the image detector, and may be, for example, a brightness range.

[0035] Specifically, when the brightness of the first image does not meet the preset brightness requirement, for example, when the brightness of the image is low, the image detector 40 cannot identify the clarity of the image well, and thus cannot adjust the focal length according to the clarity. Therefore, it is necessary to increase the brightness of the first image, that is, adjust the intensity of the light output by the optical machine.

[0036] Optionally, the main control module 50 further includes a second brightness control port 54 , which is connected to the image detector 40 , and controls the exposure time of the image detector 40 when the brightness of the first image does not meet a preset brightness requirement.

[0037] Specifically, when the brightness of the first image does not meet the preset brightness requirement, the exposure time of the image detector 40 can also be adjusted. For example, when the brightness is too high and exceeds the preset brightness requirement, that is, exceeds the preset upper limit of the brightness range, it is necessary to reduce the exposure time of the image detector 40; and when the brightness is too low and exceeds the preset lower limit of the brightness range, it is necessary to increase the exposure time of the image detector 40.

[0038] Optionally, the travel range of the electric displacement platform is 0-30 nm, thereby achieving a better focusing effect while ensuring the compactness of the device.

[0039] Optionally, the precision of the electric displacement platform is 1.5um, so that when the electric displacement platform is displaced to adjust the clarity, higher precision can ensure better focusing effect.

[0040] Optionally, the light splitting module 20 is a semi-transparent and semi-reflective mirror, and the transmission and reflection ratio of the semi-transparent and semi-reflective mirror is 50:50; the image detector 40 is located on the light transmission path of the semi-transparent and semi-reflective mirror, and the target surface 60 to be projected is located on the reflection path of the semi-transparent and semi-reflective mirror.

[0041] Specifically, in order to ensure that the focused projection image is divided into a first image and a second image with the same clarity through the spectrometer module 20, the spectrometer module 20 is a semi-transparent and semi-reflective mirror, and the transmittance and reflection ratio of the semi-transparent and semi-reflective mirror is 50:50, that is, the first image distributed to the image detector 40 and the second image distributed to the target surface 60 to be projected are the same, so that the clarity of the second image can be obtained according to the clarity of the first image.

[0042] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A high-precision projection exposure machine automatic focusing device, characterized in that: It includes a projection module, a light splitting module, an electric displacement platform, an image detector and a main control module; The projection module is fixed on the displacement platform, the spectroscopic module is located on the light output path of the projection module, and divides the focused projection image emitted by the projection module into a first image and a second image with the same clarity; the image detector is located on the propagation path of the first image, the target surface to be projected is located on the propagation path of the second image, and the distance between the target surface to be projected and the spectroscopic module is equal to the distance between the image detector and the spectroscopic module; The main control module includes an image acquisition port and a distance control port. The image acquisition port is electrically connected to the image detector and is used to receive the first image collected by the image detector. The distance control port is electrically connected to the electric displacement platform. When the clarity of the first image does not meet the preset clarity requirement, the electric displacement platform is controlled to drive the projection module to move along a first direction until the accuracy of the first image meets the preset clarity requirement. The first direction is the light emitting direction of the projection module.

2. The automatic focusing device according to claim 1, characterized in that: The focused projection image is a two-dimensional code image with a resolution of 1920*1080 and a single pixel size of 10um.

3. The automatic focusing device according to claim 1, characterized in that: The projection module includes an optical machine and a lens.

4. The automatic focusing device according to claim 3, characterized in that: The lens is a telecentric lens.

5. The automatic focusing device according to claim 3, characterized in that: The wavelength range of the light source of the optical machine is 510nm-530nm.

6. The automatic focusing device according to claim 3, characterized in that: The main control module also includes a first brightness control port, which is electrically connected to the optomechanical device, and adjusts the intensity of the light output by the optomechanical device when the brightness of the first image does not meet a preset brightness requirement.

7. The automatic focusing device according to claim 1, characterized in that: The main control module further includes a second brightness control port, which is connected to the image detector and controls the exposure time of the image detector when the brightness of the first image does not meet a preset brightness requirement.

8. The automatic focusing device according to claim 1, characterized in that: The stroke of the electric displacement platform is 0-30nm.

9. The automatic focusing device according to claim 1, characterized in that: The accuracy of the electric displacement platform is 1.5um.

10. The automatic focusing device according to claim 1, characterized in that: The light splitting module is a semi-transparent and semi-reflective mirror, and the transmission and reflection ratio of the semi-transparent and semi-reflective mirror is 50:50; The image detector is located on the light transmission path of the semi-transparent and semi-reflective mirror, and the target surface to be projected is located on the light reflection path of the semi-transparent and semi-reflective mirror.

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