TWM648751U - Variable object distance optical detection system - Google Patents

Abstract

A variable object distance optical detection system used to detect the performance parameters of the lens to be tested. The variable object distance optical detection system includes a load-bearing structure, detection module and imaging module. The detection module is arranged on the bearing structure, and the detection module includes an imaging device and a driving motor. The imaging device includes a casing, an objective lens and an image capturing unit. The casing is arranged on the bearing structure. The objective lens is installed in the casing. The image capturing unit has a photosensitive element, and the image capturing unit is disposed on the casing movably relative to the objective lens. The drive motor is disposed on the casing and connected to the image capture unit, and the drive motor is used to provide driving force to move the image capture unit relative to the objective lens, thereby changing the distance between the photosensitive element and the objective lens. The image module corresponds to the objective lens, and the lens to be tested is disposed between the objective lens and the image module.

Description

Variable object distance optical detection system

The present invention relates to an optical detection system, in particular to a variable object distance optical detection system.

Since the quality of lenses will change due to process differences during the manufacturing process, lenses assembled from lenses must be inspected before leaving the factory to ensure that the manufactured lenses meet the original design specifications. In addition, as the pixels of lenses become higher and higher, how to accurately evaluate the performance of lenses has become a key issue of concern in this field. Generally speaking, the resolving power of a lens is the ability of the lens to reproduce the details of the scene being photographed. It can be used as an important indicator to evaluate the performance of the lens. The higher the resolving power of the lens, the clearer the image.

Existing test methods for measuring the resolving power of lenses include modulation transfer function (MTF) and contrast transfer function (CTF). Most of these test methods fix the focal length of the objective lens of the detection device at Infinity or finite distance, so it can only measure the performance parameters of the lens to be tested at a single object distance position (i.e. infinite distance or finite distance). Nowadays, the use of lenses is becoming more and more widespread and diversified. The same lens may be used to shoot scenes at finite distance and infinite distance. Therefore, there is also a need to measure the resolving power of the lens at two different object distances, namely infinite distance and finite distance. However, the existing testing method with a fixed objective lens focal length position cannot simultaneously measure the performance parameters of the lens under test at two different object distances, namely infinite and finite, through a single detection device in a single test procedure. In other words, if you want to measure the performance parameters of a lens at infinite distance and limited distance, you can only manually switch the physical distance between the detection device and the lens under test in two different test procedures, for example. , to test the performance parameters of the lens at infinite distance and finite distance.

The present invention provides a variable object distance optical detection system to solve the problem in the prior art that it is impossible to simultaneously measure the performance parameters of the lens to be tested at infinite distance and finite distance through a single detection device in a single test procedure.

The variable object distance optical detection system disclosed in one embodiment of the present invention is used to detect the performance parameters of a lens to be tested. The variable object distance optical detection system includes a carrying structure, a detection module and an image module. The detection module is arranged on the bearing structure, and the detection module includes at least one imaging device and at least one driving motor. The imaging device includes a casing, an objective lens and an image capturing unit. The casing is arranged on the bearing structure. The objective lens is installed in the casing. The image capturing unit has a photosensitive element, and the image capturing unit is disposed on the casing movably relative to the objective lens. The drive motor is disposed on the casing and connected to the image capture unit, and the drive motor is used to provide driving force to move the image capture unit relative to the objective lens, thereby changing the distance between the photosensitive element and the objective lens. The image module corresponds to the objective lens, and the lens to be tested is disposed between the objective lens and the image module.

According to the variable object distance optical detection system disclosed in the above embodiments, the distance between the photosensitive element and the objective lens is changed by automatically driving the image capture unit of the imaging device through a drive motor, without having to manually move the entire detection module relative to The movement of the lens under test saves the operating time required to manually adjust the position of the detection module, so that the performance parameters of the lens under test at infinity and at finite distance can be measured using the variable object distance optical detection system in a single test program. distance performance parameters. In this way, lens inspection of multiple object distances can be completed more efficiently.

The above description of the content of the present invention and the following description of the embodiments are used to demonstrate and explain the principles of the present invention, and to provide a further explanation of the patent application scope of the present invention.

The detailed features and advantages of the embodiments of the present invention are described in detail below in the implementation mode. The content is sufficient to enable anyone with ordinary knowledge in the art to understand the technical content of the embodiments of the present invention and implement them accordingly, and based on the disclosure in this specification With the content, patent scope and drawings, anyone with ordinary knowledge in the art can easily understand the relevant purposes and advantages of the present invention. The following examples are intended to further illustrate the concepts of the present invention in detail, but are not intended to limit the scope of the present invention in any way.

Please refer to Figures 1 to 3. Figure 1 is a three-dimensional schematic diagram of the variable object distance optical detection system and the lens to be tested according to the first embodiment of the present invention. Figure 2 is the variable object distance optical detection system of Figure 1. A three-dimensional schematic diagram of one of the imaging devices and one of the driving motors when detecting that the lens to be tested is located at an infinite distance, and Figure 3 is one of the variable object distance optical detection systems in Figure 1 detecting that the lens to be tested is located at a limited distance. A schematic three-dimensional view of the imaging device and one of the drive motors.

The variable object distance optical detection system 1 of this embodiment is used to detect the performance parameters of a lens 9 under test at different object distances. For example, the variable object distance optical detection system 1 can be used to detect the lens resolving power value, opto-electronic conversion function (OECF), gray scale or optical spatial frequency of the lens 9 under test at different object distances. Spatial Frequency Response (SFR) and other performance parameters, but the present invention is not limited to this. In addition, the variable object distance optical detection system 1 detects the lens resolving power of the lens 9 to be tested at different object distances through methods such as modulation transfer function (MTF) or contrast transfer function (CTF). numerical value.

The variable object distance optical detection system 1 includes a carrying structure 10 , a detection module 11 and an image module 13 . Among them, the detection module 11 is arranged on the bearing structure 10 , and the lens 9 to be tested is arranged between the detection module 11 and the image module 13 . The detailed structural configuration of the load-bearing structure 10 , the detection module 11 and the imaging module 13 in this embodiment will be further described in detail below.

The bearing structure 10 may include a base 100, two arc-shaped rails 102 and three extending arms 101. The two arc-shaped tracks 102 are provided on the base 100 and extend in different directions. One of the three extension arms 101 is directly fixed to the base 100 and is located between the two arc-shaped rails 102, while the other two extension arms 101 are respectively slidably disposed on the two arc-shaped rails 102. Therefore, the two extension arms 101 are indirectly arranged on the base 100 through the two arc-shaped rails 102 respectively. Among them, the three extension arms 101 all extend from the base 100 toward the image module 13 .

The detection module 11 includes three imaging devices 110 and three driving motors 112 . The three imaging devices 110 are respectively provided on the three extension arms 101 , and the three driving motors 112 are respectively provided on the three imaging devices 110 . Because the two extension arms 101 provided on the two arc-shaped rails 102 can slide along the two arc-shaped rails 102, and the two imaging devices 110 provided on the two extension arms 101 are tilted For the lens 9 to be tested, the tilt angle of the two imaging devices 110 relative to the lens 9 to be tested can be adjusted through this configuration. The tilt angles of the two imaging devices 110 relative to the lens 9 to be measured may be the same or different from each other, and the invention is not limited thereto.

Since the three imaging devices 110 have similar structural features, and the three driving motors 112 have similar structural features, unless the number is specified in particular, only one of the imaging devices 110 and its corresponding One driving motor 112 and one extension arm 101 are described, but the invention is not limited thereto.

The imaging device 110 includes a casing 1100, an objective lens 1101 and an image capturing unit 1102. Among them, the casing 1100 is fixed on the extension arm 101 of the carrying structure 10, the objective lens 1101 is set on the casing 1100, the image capture unit 1102 has a photosensitive element IMS, and the image capture unit 1102 is movably disposed on the machine relative to the objective lens 1101. Shell 1100.

The driving motor 112 is disposed on the casing 1100 of the imaging device 110 and connected to the image capturing unit 1102, and the driving motor 112 is used to provide driving force to move the image capturing unit 1102 relative to the objective lens 1101, thereby changing the image capturing unit 1102. The distance between the photosensitive element IMS and the objective lens 1101. Specifically, the driving motor 112 may include a power component 1120 and a lead screw 1122, where the power component 1120 is disposed on the casing 1100 of the imaging device 110, and one end of the lead screw 1122 is connected to the power component 1120 and the other end is connected to the Image capture unit 1102, and the power assembly 1120 is used to provide driving force to rotate the lead screw 1122, so that the lead screw 1122 can drive the image capture unit 1102 to move relative to the objective lens 1101 to change the distance between the photosensitive element IMS and the objective lens 1101 . Thereby, the performance parameters of the lens 9 to be tested under different object distances can be detected. For example, when the object distance of the lens 9 to be tested is infinite, the imaging plane formed by the lens 9 to be tested and the objective lens 1101 is relatively close to the objective lens 1101, so the image capture unit 1102 needs to be moved toward the objective lens 1101 through the drive motor 112. The photosensitive element IMS in the image capturing unit 1102 is positioned on the imaging surface, so that the light can be clearly imaged on the photosensitive element IMS after passing through the lens 9 and the objective lens 1101 to be measured. On the other hand, when the object distance of the lens 9 to be tested is limited, the imaging surface formed by the lens 9 to be tested and the objective lens 1101 is relatively far away from the objective lens 1101, so the image capture unit 1102 needs to be moved away from the objective lens 1101 through the drive motor 112. The direction is moved so that the photosensitive element IMS in the image capture unit 1102 is located on the imaging surface, so that the light can be clearly imaged on the photosensitive element IMS after passing through the lens 9 and the objective lens 1101 to be measured.

Furthermore, through the driving of the driving motor 112, the image capture unit 1102 and its photosensitive element IMS can be moved relative to the objective lens 1101 along the extension direction of the extension arm 101, and the image capture unit 1102 has a first element relatively close to the objective lens 1101. position and a second position relatively far away from the objective lens 1101 (that is, the image capturing unit 1102 is closer to the objective lens 1101 when it is in the first position than when it is in the second position). As shown in FIG. 2 , when the driving motor 112 moves the image capturing unit 1102 to the first position, the imaging device 110 is used to detect the performance parameters of the lens 9 under test at an infinite distance. As shown in FIG. 3 , when the driving motor 112 moves the image capturing unit 1102 to the second position, the imaging device 110 is used to detect the performance parameters of the lens 9 under test at a limited distance. In one implementation, the lens 9 to be tested can be zoomed through mechanical external force, for example, so that the variable object distance optical detection system 1 can detect its performance parameters at a limited distance and its performance parameters at an infinite distance.

Through the above configuration, the tester can set the variable object distance optical detection system 1 so that the variable object distance optical detection system 1 can match different object distances of the lens 9 under test in a single test program and automatically drive and take out the lens through the drive motor 112. The image capture unit 1102 of the imaging device 110 changes the distance between the photosensitive element IMS and the objective lens 1101 to respectively detect the performance parameters of the lens 9 under test when it is located at an infinite distance and a limited distance.

The image module 13 corresponds to the objective lens 1101, and the lens 9 to be tested is disposed between the objective lens 1101 and the image module 13. Specifically, there may be a detection area (not otherwise labeled) between the detection module 11 and the image module 13, and the lens 9 to be tested is arranged in the detection area. The lens 9 to be tested may be carried, for example, by a carrier (not shown) located in the detection area, but the present invention is not limited to this. In this embodiment, the two arc-shaped tracks 102 of the load-bearing structure 10 each have a fixed radius of curvature, and the respective centers of curvature of the two arc-shaped tracks 102 are located in the detection area.

Please refer to FIG. 4 , which is a schematic diagram of three target patterns projected by the image module of the variable object distance optical detection system in FIG. 1 . The image module 13 is used to project at least one of a plurality of target patterns 130 to the lens 9 to be measured, and these target patterns 130 have different patterns from each other. The three imaging devices 110 are used to capture at least one of the target patterns 130 through the lens 9 to be tested, so as to detect the performance parameters of the lens 9 to be tested. For example, the light of the target pattern 130 projected by the image module 13 passes through the lens 9 to be tested and enters the objective lens 1101 of the imaging device 110 , so that the light rays pass through the lens 9 to be tested and the objective lens 1101 to converge and form an image on the image capture unit 1102 The photosensitive element is on the IMS. The different target patterns 130 may be a resolution target to evaluate the lens resolution and detail reproduction capability, an MTF target to evaluate the lens modulation transfer function, a color correction target to evaluate the lens color reproduction capability and chromatic aberration, etc. In addition, in some embodiments, one of the target patterns 130 can be used for the imaging device 110 of the detection module 11 to detect the performance parameters of the lens 9 at an infinite distance, and one of the target patterns 130 The other one can be used by the imaging device 110 to detect the performance parameters of the lens 9 under test at a limited distance. As shown in Figure 4, there are three target patterns 130 that can be projected by the image module 13, which can be used by the imaging device 110 to detect different performance parameters of the lens 9 to be tested at a limited distance or an infinite distance. However, the present invention is not limited to the styles of these target patterns.

When using the variable object distance optical detection system 1 to detect the lens 9 to be tested, the lens 9 to be tested is placed in the detection area. The image module 13 generates an image as a target pattern 130 for detection and projects the image to the lens 9 to be tested. The three imaging devices 110 of the imaging module 13 capture the image through the lens 9 to be tested. Two of the imaging devices 110 can tilt toward the lens 9 to be tested to capture the image. Thereby, the image of the target pattern 130 used for detection can be captured by the three imaging devices 110 at various angles. Next, the image module 13 can generate another image as another target pattern 130 for detection. This other image can be captured by the image module 13 at various angles. Based on the images captured by these three imaging devices 110, the condition and quality of the lens 9 to be tested can be determined.

Please refer to Figure 5, which is a chart drawn from the data obtained by the variable object distance optical detection system in Figure 1 when detecting the lens to be tested. The variable object distance optical detection system 1 of this embodiment can further perform a through focus test on each field of view of the lens 9 to be tested. FIG. 5 shows the through-focus result of one of the field-of-view measurements of the lens 9 to be measured by one of the imaging devices 110 in the variable object distance optical detection system 1 . As shown in FIG. 5 , the image capturing unit 1102 can be moved by the driving motor 112 to move the photosensitive element IMS back and forth in front of the imaging surface, and for example, the photosensitive element IMS can be calculated at a position every 0.01 millimeters (mm) away from the imaging front and back. The MTF value of the received image can then evaluate the depth of focus and other properties of the lens 9 to be tested.

In this embodiment, the number of imaging devices 110 , drive motors 112 and extension arms 101 is three, but the invention is not limited thereto. In other embodiments, the number of imaging devices, driving motors, and extension arms may be one, two, or more than four.

According to the variable object distance optical detection system of the above embodiment, the image capture unit of the imaging device is automatically driven by the drive motor to change the distance between the photosensitive element and the objective lens, without the need to manually move the entire detection module relative to the object to be measured. The lens movement saves the operating time required to manually adjust the position of the detection module, so that the performance parameters of the lens under test at infinite distance and at a limited distance can be measured using the variable object distance optical detection system in a single test program. Performance parameters. In this way, lens inspection of multiple object distances can be completed more efficiently.

Although the present invention has been disclosed in the foregoing preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the similar art can make some modifications and modifications without departing from the spirit and scope of the present invention. Therefore, this invention The scope of patent protection for a new model shall be determined by the scope of the patent application attached to this specification.

1: Variable object distance optical detection system 10: Load-bearing structure 100: base 102: Arc track 101:Extension arm 11:Detection module 110: Image capture device 1100:Chassis 1101:Objective lens 1102:Image capture unit IMS: photosensitive element 112: Drive motor 1120: Power components 1122:Lead screw 13:Image module 130:Target pattern 9: Lens to be tested

Figure 1 is a schematic three-dimensional view of a variable object distance optical detection system and a lens to be tested according to the first embodiment of the present invention. FIG. 2 is a schematic three-dimensional view of one of the imaging devices and one of the driving motors when the variable object distance optical detection system of FIG. 1 detects that the lens to be tested is located at an infinite distance. FIG. 3 is a schematic three-dimensional view of one of the imaging devices and one of the driving motors when the variable object distance optical detection system of FIG. 1 detects that the lens to be tested is located at a limited distance. FIG. 4 is a schematic diagram of three target patterns projected by the image module of the variable object distance optical detection system of FIG. 1 to be projected by the lens to be tested. FIG. 5 is a chart drawn by the data obtained by detecting the lens to be tested by the variable object distance optical detection system of FIG. 1 .

1: Variable object distance optical detection system

10: Load-bearing structure

100: base

102: Arc track

101:Extension arm

11:Detection module

110: Image capture device

1100:Chassis

1101:Objective lens

1102:Image capture unit

112: Drive motor

13:Image module

9: Lens to be tested

Claims (8)

A variable object distance optical detection system is used to detect the performance parameters of a lens to be tested. The variable object distance optical detection system includes: A load-bearing structure; a detection module, disposed on the load-bearing structure, the detection module including at least one imaging device and at least one drive motor, the at least one imaging device including a casing, an objective lens and an image capture unit , the casing is disposed on the bearing structure, the objective lens is disposed on the casing, the image capture unit has a photosensitive element, the image capture unit is movably disposed on the casing relative to the objective lens, and the at least one drive motor Disposed on the casing and connected to the image capture unit, the at least one drive motor is used to provide driving force to move the image capture unit relative to the objective lens, thereby changing the distance between the photosensitive element and the objective lens; and an image module corresponding to the objective lens, and the lens to be tested is disposed between the objective lens and the image module. The variable object distance optical detection system of claim 1, wherein the at least one drive motor includes a power component and a lead screw, the power component is disposed on the casing, and one end of the lead screw is connected to the power component, The other end of the lead screw is connected to the image capture unit, and the power component is used to provide driving force to rotate the lead screw, so that the lead screw can drive the image capture unit to move relative to the objective lens to change the photosensitivity The distance between the element and this objective. The variable object distance optical detection system of claim 1, wherein the bearing structure includes a base and at least one extension arm, the at least one extension arm is disposed on the base and extends from the base toward the image module , the casing of the at least one imaging device is disposed on the at least one extension arm, and the photosensitive element of the image capture unit can move relative to the objective lens along the extension direction of the at least one extension arm. The variable object distance optical detection system of claim 3, wherein the number of the at least one imaging device, the at least one drive motor and the at least one extension arm is three, and the load-bearing structure further includes Two arc-shaped rails of the base, one of the extension arms is fixed to the base, and the other two extension arms are slidably disposed on the two arc-shaped rails respectively. The casings of each of the three imaging devices are respectively The three drive motors are provided on the three extension arms, and the three drive motors are respectively provided on the casings of the three imaging devices. The variable object distance optical detection system according to claim 4, wherein there is a detection area between the detection module and the image module, the lens to be tested is used to be arranged in the detection area, and the two arc-shaped tracks Each has a fixed radius of curvature, and the center of curvature of each of the two arc-shaped tracks is located in the detection area. The variable object distance optical detection system as claimed in claim 1, wherein the image capturing unit has a first position relatively close to the objective lens and a second position relatively far away from the objective lens; when the at least one driving motor drives the When the image capturing unit moves to the first position, the at least one imaging device is used to detect the performance parameters of the lens to be tested at an infinite distance; when the at least one driving motor moves the image capturing unit to the second When the lens is in a limited distance, the at least one imaging device is used to detect the performance parameters of the lens to be tested at a limited distance. The variable object distance optical detection system of claim 1, wherein the image module is used to project at least one of a plurality of target patterns to the lens to be tested, and the target patterns have different patterns from each other. The variable object distance optical detection system as described in claim 7, wherein one of the target patterns is used for the at least one imaging device to detect the performance parameters of the lens to be tested at an infinite distance, and the Another one of the target patterns is used for the at least one imaging device to detect the performance parameters of the lens to be tested at a limited distance.