TW202004120A - Measurement system and measurement method - Google Patents

Abstract

A measurement system adapted to an object is provided. The measurement system includes a light source, two splitter elements, a light guide device, and two sensing elements. One of the splitter elements is disposed on a downstream of a light path of the light source. The light guide device is disposed on a downstream of a first light path of the one of the splitter elements. The other one of the splitter elements is disposed on a downstream of a first light path of the light guide device. One of the sensing elements is disposed on a downstream of a second light path of the one of the splitter elements. The other one of the sensing elements is disposed on a downstream of a first light path of the other one of the splitter elements. In addition, a measurement method is also provided.

Description

Measuring system and measuring method

The invention relates to a measurement system and a measurement method of an optical element.

With the development of the technology industry, the types, functions and methods of optical devices are becoming more and more diverse, and the use and matching of optical components are becoming more and more extensive. In addition, due to the trend of miniaturization of optical devices, the optical components used and matched also need to be miniaturized. Therefore, it is necessary to measure optical components through precise instruments to maintain better optical quality.

However, in today's measurement technology, the optical element is mainly measured by a destructive measurement method, for example, the optical element is processed and cut into a right-angle shape for optical measurement, so that the optical element will be wasted. In today's measurement technology, multiple light sources are often used as measurement light. As a result, the measuring instruments are too complicated and the cost is high. In addition to this, there is also the problem of difficulty in optical correction. Therefore, how to design a measuring instrument that is relatively simple and does not consume optical elements and how to use it are commonly devised by those skilled in the art.

The invention provides a measurement system and a measurement method, which can perform rapid optical measurement and can simplify the structure and reduce its cost, and can solve the problem that the traditional measurement method needs to destroy the object to be measured for measurement.

An embodiment of the present invention provides a measurement system suitable for measuring an object to be measured. The measurement system includes a light source, two beam splitting elements, a light guide device, and two sensing elements. One of the two dichroic elements is located downstream of the light path of the light source. The light guide device is provided downstream of the first optical path of one of the two beam splitting elements. The other of the two beam splitting elements is located downstream of the first optical path of the light guide device. One of the two sensing elements is located downstream of the second optical path of one of the two beam splitting elements. The other of the two sensing elements is disposed downstream of the first optical path of the other of the two beam splitting elements. Therefore, the measurement system can confirm the optical properties by using a single light source to perform rapid optical measurements on both sides of the object to be measured.

Another embodiment of the present invention provides a measurement method suitable for an object to be measured. The measurement method includes the following steps: First, provide the first beam and the second beam of the measurement system to the opposite first and second surfaces of the object to be measured. Then, the first light beam and the second light beam reflected by the object to be detected are detected to obtain two first focus coordinates of the first surface and the second surface. Finally, the shape thickness of the object to be measured is calculated based on the two first focus coordinates.

Based on the above, in the measurement system and measurement method of the present invention, the measurement system can divide the light beam emitted by the single light source into the first light beam and the second light beam by the spectroscopic element, and respectively on the first surface and the second surface of the object to be measured Focus the surface to get the focus position of the first surface and the second surface, and then calculate the optical information of the test object from the focus position information. In this way, in this embodiment, the measurement system uses only a single light source to perform rapid optical measurement on the opposite sides of the object to confirm its optical properties, and can simplify the structure of the measurement system and reduce its cost. In addition, it can solve the problem that the traditional measurement method needs to destroy the object to be measured.

In order to make the above-mentioned features and advantages of the present invention more obvious and understandable, the embodiments are specifically described below in conjunction with the accompanying drawings for detailed description as follows.

FIG. 1 is a schematic diagram of a measurement system according to an embodiment of the invention. Please refer to FIG. 1. In this embodiment, the measurement system 100 is suitable for measuring the object 10 to be measured. For example, the object 10 is a non-planar lens such as a biconcave lens, a biconvex lens, a meniscus lens, a convex-concave lens, a plano-convex lens, or a plano-concave lens. The optical elements with curvatures on the surface, such as 稜鏡 or integrating column, the invention is not limited to this. In this embodiment, the object to be measured 10 is, for example, a lenticular lens.

The measurement system 100 includes a light source 110, beam splitting elements 120, 130, sensing elements 140, 150, and light guide devices 180_1, 180_2.

The light source 110 is an electronic device that can emit a light beam L, for example, a laser device (Laser device), however, the invention is not limited to its type.

The beam splitting elements 120 and 130 are optical elements that can partially reflect and partially transmit the light beam L, for example, beam splitters. In this embodiment, the beam splitting elements 120 and 130 are, for example, beam splitters with a transmittance ranging from 40% to 60%. In a preferred embodiment, the transmittance of the beam splitter is about 50%, but the invention is not limited to this.

The sensing elements 140 and 150 are electronic devices that can detect light intensity, such as a photo detector.

The light guide devices 180_1, 180_2 may be any device or optical element that can guide the light beam L to be transmitted in a specified direction. In this embodiment, the light guide devices 180_1 and 180_2 are, for example, two mirrors, but the invention is not limited thereto.

In addition, more specifically, the measurement system 100 of this embodiment further includes objective lenses 170_1, 170_2, 170_3, and 170_4 for focusing the light beam, but the present invention is not limited to this, and the number, type, and type thereof are also No restrictions.

In this embodiment, the light source 110 provides a light beam L. The spectroscopic element 120 is provided downstream of the optical path of the light source 110. The light guide devices 180_1 and 180_2 are provided downstream of the first optical path of the light splitting element 120. The spectroscopic element 130 is provided downstream of the first optical path of the light guide devices 180_1 and 180_2. The sensing element 140 is disposed downstream of the second optical path of the beam splitter 120. The sensing element 150 is disposed downstream of the first optical path of the spectroscopic element 130, as shown in FIG.

In detail, in this embodiment, when the light beam L provided by the light source 110 is transmitted to the beam splitter 120, the beam splitter 120 splits the first beam L1 and the second beam L2. The objective lens 170_1 is located between the spectroscopic element 120 and the object to be measured 10, and is used to focus the second light beam L2 transmitted by the spectroscopic element 120 on the object to be measured 10. The objective lens 170_2 is located between the spectroscopic element 120 and the sensing element 140 for focusing the second light beam L2 reflected by the object to be measured 10 on the sensing element 140. The objective lens 170_3 is located between the spectroscopic element 130 and the object to be measured 10, and is used to focus the first light beam L1 transmitted by the spectroscopic element 130 on the object to be measured 10. The objective lens 170_4 is located between the spectroscopic element 130 and the sensing element 150 for focusing the first light beam L1 reflected by the object to be measured 10 on the sensing element 150. The light guide devices 180_1 and 180_2 are located between the light splitting elements 120 and 130 to reflect the first light beam L1 transmitted by the light splitting element 120 to the light splitting element 130.

Before the measurement starts, the optical axis of the object to be measured 10 and the measurement system 100 can be corrected by standard jigs or image discrimination correction methods, but the invention is not limited to this.

FIG. 2 is a schematic diagram of measuring a test object according to an embodiment of the invention. Please refer to FIGS. 1 and 2 at the same time. During the measurement process of this embodiment, the following measurement steps may be performed to measure a shape thickness of the object 10 to be measured. Shape thickness refers to the actual thickness of a single object. Specifically, the light source 110 provides a beam L to the beam splitter 120, and the beam L is transmitted and reflected in the beam splitter 120 to form a first beam L1 and a second beam L2, respectively. The first light beam L1 is transmitted by the beam splitter 120 and reflected by the light guide devices 180_1, 180_2 to the beam splitter 130, and then reflected by the beam splitter 130 to the objective lens 170_3, and is focused on the first surface S1 of the object 10 by the objective lens 170_3 On (that is, focus C1). On the other hand, the second light beam L2 is reflected by the beam splitter 120 to the objective lens 170_1, and is focused by the objective lens 170_1 on the second surface S2 of the object to be measured 10 (that is, the focal point C2).

After the first light beam L1 and the second light beam L2 are focused on the first surface S1 and the second surface S2 of the object 10 to be measured, the first light beam L1 is reflected back to the objective lens 170_3 through the first surface S1 of the object 10 and transmitted The spectroscopic element 130 reaches the objective lens 170_4, and finally focuses to the sensing element 150 via the objective lens 170_4. The second light beam L2 is reflected back to the objective lens 170_1 via the second surface S2 of the object to be measured 10, and transmits the spectroscopic element 120 to the objective lens 170_2, and finally is focused to the sensing element 140 through the objective lens 170_2, as shown in FIG.

Therefore, in the above measurement step, the first surface S1 and the second surface can be obtained by focusing the first light beam L1 and the second light beam L2 on the first surface S1 and the second surface S2 of the object 10 to be measured, respectively The focus position of S2, and then the shape thickness of the object 10 to be measured is calculated from the focus position information. In this way, in this embodiment, the measurement system 100 can use only a single light source 110 to perform rapid optical measurement on the opposite sides of the object 10 to confirm its shape and thickness, and can simplify the structure of the measurement system 100 and reduce its Cost. In addition to this, since the object to be measured 10 can be measured without destroying it, the object to be measured 10 having a diameter of less than 10 mm can be measured.

In this embodiment, the measurement system 100 may further include a mobile platform 160 disposed between the beam splitting elements 120 and 130. The mobile platform 160 is, for example, a platform device that can move in one, two, or three dimensions, and a structure for fixing the object to be measured 10, such as an optical element holder and a movable optical stage, but the present invention is not limited to this. The position of the object 10 to be measured is recorded by the mobile platform 160 as coordinate information. Specifically, in the above measurement process, the object 10 is moved to focus the first light beam L1 on the first surface S1 and the object 10 is moved to focus the second light beam L2 on the second surface S2, Record the position of the first surface S1 and the position of the second surface S2 as two first focus coordinates, and then calculate the shape thickness of the object to be measured. However, in other embodiments, the device for moving the object 10 can also be provided by an additional fixture, and the present invention is not limited thereto.

In addition, after the above measurement step, the above measurement step can be performed on a reference object with a known shape and thickness, thereby obtaining two first focus coordinates where the first light beam L1 and the second light beam L2 are focused on opposite sides of the reference object , And the shape thickness of the object to be measured 10 is calculated by the difference between the two first focus coordinates of the object to be measured 10 and the reference object, but the invention is not limited thereto.

FIG. 3 is a schematic diagram of measuring a test object according to another embodiment of the present invention. Please refer to FIG. 1 and FIG. 3 at the same time. In the measurement process of this embodiment, subsequent measurement steps may be performed after the shape and thickness of the object 10 are obtained to further measure the material thickness of the object 10. The thickness of the material refers to the thickness of the light beam traveling in the object 10 to be measured, which is affected by the refractive index of the object 10, and the material thickness will be different from the thickness of the shape. Specifically, the first light beam L1 provided by the light source 110 is used to form a focus point (ie, focus C1) on the first surface S1 of the object 10, and the object 10 is moved toward the objective lens 170_3 to make the first light beam L1 The focal point of is transferred from the first surface S1 of the object 10 to the second surface S2 of the object 10 (that is, the focal point C2). Therefore, the sensing element 150 can detect the first light beam L1 reflected by the object 10 to obtain two second focus coordinates of the first surface S1 and the second surface S2.

In this way, the focus of the first surface S1 and the second surface S2 can be obtained by focusing the first light beam L1 on the first surface S1 and the second surface S2 of the object 10 in the above measurement step Position, and then calculate the material thickness of the object 10 from the focus position information. In this step, the material thickness of the object to be measured 10 can also be calculated by comparing with the material thickness of the reference object. The comparison method of the thickness difference is similar to the comparison method of the aforementioned measurement step, so it will not be repeated here.

FIG. 4 is a schematic diagram of measuring a test object according to another embodiment of the present invention. Please refer to FIGS. 1 and 4 at the same time. In the measurement process of this embodiment, subsequent measurement steps may be performed after the material thickness of the object 10 is obtained to further measure a radius of curvature of one side of the object 10 . Specifically, the first light beam L1 provided by the light source 110 is used to move the object to be measured 10 so that the spherical center of a focusing element coincides with the spherical center R of the first surface S1 of the object to be measured 10. When the focusing element coincides with the spherical center of the object to be measured 10, the first light beam L1 will generate total reflection on the first surface S1 of the object to be measured 10. In this embodiment, the focusing element is the objective lens 170_3, but in other embodiments, a focusing element with a known radius of curvature may be additionally configured for measurement, and the present invention is not limited thereto.

In this way, in the above measurement step, the position of the first surface S1 can be obtained by the first beam L1 reflected by the object to be measured 10, and then the radius of curvature of the object to be measured 10 can be calculated from the reflected position information . The comparison method of the difference between the curvature radius of the object to be measured 10 and the curvature radius of the focusing element is similar to the comparison method of the foregoing measurement steps, so it will not be repeated here.

-----------------------------(1) 其中： n₀ ：空氣的折射率； n：待測物的折射率； l₁ ：待測物的形狀厚度； l₂ ：待測物的材質厚度； r：待測物的第一面的曲率半徑。In addition, in this embodiment, the refractive index of the object to be measured 10 can be further calculated according to the shape thickness, material thickness and curvature radius obtained by the above three measurement steps through formula calculation. Specifically, the refractive index can be defined according to the following formula (1):

-----------------------------(1) where: n ₀ : refractive index of air; n: refractive index of the object to be measured ; L ₁ : shape and thickness of the object to be measured; l ₂ : material thickness of the object to be measured; r: radius of curvature of the first surface of the object to be measured

In this way, in the above-mentioned three different measurement steps in this embodiment, the measurement system 100 can measure the object to be measured 10 using only a single light source 110 to perform a quick optical measurement to confirm its optical properties, and then obtain the The thickness of the shape, the thickness of the material, the radius of curvature, and its refractive index can simplify the architecture of the measurement system 100 and reduce its cost.

In addition to the above measurement steps, the light source 110 of this embodiment can be further replaced to provide another light beam with a different wavelength for optical measurement. Specifically, the first light beam L1 and another light beam (not shown) are provided to form a focus point (ie, focus C1) on the first surface S1 of the object 10 to be measured, and move under different beams to be measured The object 10 moves toward the objective lens 170_3 so that the focus shifts from the first surface S1 of the object 10 to the second surface S2 of the object 10 (that is, the focal point C2). Material thickness. Therefore, the Abbe number of the test object 10 can be calculated according to this measurement method.

In addition to the above measurement steps, the measurement system of this embodiment may further mount a temperature control module, which is disposed on the object 10 to change the temperature of the object 10. For example, the temperature control module is, for example, a heatable electronic device, a heat pipe, or other various types of heating devices, and the present invention is not limited thereto. In this way, the above-mentioned optical measurement can be performed under the condition that the test object 10 is at different temperatures, and then the refractive index change value of the test object 10 at different temperatures can be obtained.

FIG. 5 is a flowchart of steps of a measurement method according to an embodiment of the invention. Please refer to FIGS. 1 and 5. The measurement method of this embodiment can be applied to at least the measurement device 100 of FIG. 1. Therefore, the measurement device 100 of the embodiment of FIG. 1 will be taken as an example below, but the invention is not limited thereto. In this embodiment, step S500 is first performed to provide the first light beam L1 and the second light beam L2 of the measurement system 100 to the opposite first surface S1 and second surface S2 of the object to be measured 10. Next, step S510 is performed to detect the first light beam L1 and the second light beam L2 reflected by the object 10 to obtain two first focus coordinates of the first surface S1 and the second surface S2. Next, step S520 is performed, and the shape thickness of the object 10 to be measured is calculated according to the two first focus coordinates. In this way, the shape and thickness of the object to be measured 10 can be obtained by the above measurement steps.

After completing the above step S520, the user can selectively continue to step S530 according to needs, provide the first light beam L1 and move the object 10 to move the focus of the first light beam L1 from the first surface S1 of the object 10 To the second surface S2 of the object to be measured 10. Then, step S540 is performed to detect the first light beam L1 reflected by the object 10 to obtain two second focus coordinates of the first surface S1 and the second surface S2. Next, step S550 is performed, and the material thickness of the object 10 to be measured is calculated according to the two second focus coordinates. In this way, the material thickness of the object to be measured 10 can be obtained by the above measurement steps.

After completing the above step S550, the user can selectively continue to step S560 according to needs, providing the first light beam L1 and moving the object to be measured 10 so that the spherical center of the focusing element (ie, objective lens 170_1 or objective lens 170_3) coincides with the first surface The heart of S1. Next, step S570 is performed to detect the first light beam L1 reflected by the object 10 to obtain the radius of curvature of the first surface S1. In this way, the radius of curvature of one side of the object to be measured 10 can be obtained by the above measurement steps.

After completing the above step S570, the user can selectively continue to step S580 according to needs, and obtain the refractive index value of the test object 10 according to the shape thickness and material thickness of the test object 10 and the curvature radius of the first surface S1. In other words, the refractive index value of the test object 10 is obtained by performing the calculation of the above formula (1) based on the optical information of the test object 10 obtained in step S520, step S550, and step S570.

In summary, in the measurement system and the measurement method of the present invention, the measurement system can divide the light beam emitted by a single light source into the first light beam and the second light beam by the beam splitter on the first surface and the second surface of the object to be measured, respectively Focus the surface to get the focus position of the first surface and the second surface, and then calculate the optical information of the test object from the focus position information. In this way, in this embodiment, the measurement system uses only a single light source to perform rapid optical measurement on the opposite sides of the object to confirm its optical properties, and can simplify the structure of the measurement system and reduce its cost. In addition, it can solve the problem that the traditional measurement method needs to destroy the object to be measured.

Although the present invention has been disclosed as above with examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be subject to the scope defined in the appended patent application.

10‧‧‧Object to be measured 100‧‧‧Measurement system 110‧‧‧ Light source 120, 130‧‧‧ Spectroscopic element 140, 150‧‧‧ Sensing element 160‧‧‧Mobile platform 170_1, 170_2, 170_3, 170_4‧‧ ‧Object lens 180_1, 180_2‧‧‧‧Light guide device C1, C2‧‧‧focus L‧‧‧beam L1‧‧‧first beam L2‧‧‧second beam R‧‧‧sphere center S1‧‧‧ S2‧‧‧Second side S500, S510, S520, S530, S540, S550, S560, S570, S580‧‧‧

FIG. 1 is a schematic diagram of a measurement system according to an embodiment of the invention. FIG. 2 is a schematic diagram of measuring a test object according to an embodiment of the invention. FIG. 3 is a schematic diagram of measuring a test object according to another embodiment of the present invention. FIG. 4 is a schematic diagram of measuring a test object according to another embodiment of the present invention. FIG. 5 is a flowchart of steps of a measurement method according to an embodiment of the invention.

10‧‧‧ test object

100‧‧‧Measurement system

110‧‧‧Light source

120、130‧‧‧Split element

140, 150‧‧‧ sensing element

160‧‧‧Mobile platform

170_1, 170_2, 170_3, 170_4‧‧‧‧Objective

180_1, 180_2‧‧‧Light guide device

L‧‧‧beam

L1‧‧‧First beam

L2‧‧‧Second beam

S1‧‧‧The first side

S2‧‧‧Second side

Claims (12)

A measurement system is suitable for measuring an object to be measured. The measurement system includes: a light source; a first beam splitting element located downstream of the light path of the light source; and a light guide device provided in the first beam path of the first branching element Downstream; a second beam splitting element, located downstream of the first optical path of the light guide device; a first sensing element, positioned downstream of the second optical path of the first beam splitting element; and a second sensing element, located at The first optical path of the second light splitting element is downstream. The measurement system as described in item 1 of the patent application scope further includes: a mobile platform disposed between the first spectroscopic element and the second spectroscopic element, and the object to be tested is disposed on the mobile platform to A splitting element moves between the second splitting element. The measurement system according to item 1 of the patent application scope, wherein the first beam splitting element and the second beam splitting element are beam splitters with a transmittance ranging from 40% to 60%. The measurement system as described in item 1 of the patent application scope further includes: a temperature control module, adjacent to the object to be measured, for changing the temperature of the object to be measured. A measurement method is suitable for an object to be measured. The measurement method includes: providing a first beam and a second beam of a measurement system to opposite first and second surfaces of the object to be detected; detecting the The first light beam and the second light beam reflected by the object to be measured to obtain two first focus coordinates of the first surface and the second surface; and calculating one of the object to be measured according to the two first focus coordinates Shape thickness. The measurement method as described in item 5 of the patent application scope, wherein the measurement method further includes one of the following steps: (1) the first light beam and the second light beam are respectively formed by a single light source through a beam splitter, (2 ) Calibrate the optical axis of the object to be measured and the measurement system with a standard jig or image discrimination correction method, (3) the method of obtaining the two first focus coordinates further includes: moving the object to be measured so that the first light beam Focusing and moving the object under test on the first surface to focus the second beam on the second surface, and recording the positions of the first surface and the second surface as the two first focusing coordinates, (4) The method of calculating the thickness of the shape of the object to be measured includes: calculating the thickness of the shape according to the difference between the thickness of a reference object and the two first focus coordinates. The measurement method as described in item 5 of the patent application scope further includes: providing the first light beam and moving the object to be measured so that the focus of the first light beam is transferred from the first surface of the object to the object The second surface of the test object; detecting the first beam reflected by the test object to obtain two second focus coordinates of the first surface and the second surface; and calculating based on the two second focus coordinates A material thickness of the object to be measured. The measurement method as described in item 7 of the patent application scope, wherein the method for calculating the material thickness of the object under test based on the two first focus coordinates includes: based on the thickness of a reference object and the two second focus coordinates To calculate the thickness of the material. The measurement method as described in item 8 of the patent application range, wherein the measurement system further includes a focusing element, and the measurement method further includes: providing the first light beam and moving the object to be measured so that the spherical centers of the focusing elements coincide A sphere center on the first surface; and detecting the first beam reflected by the object to obtain a radius of curvature of the first surface. The measurement method as described in item 9 of the patent application scope, wherein the measurement method further comprises: obtaining a value of the test object based on the shape thickness and the material thickness of the test object and the curvature radius of the first surface Refractive index value. The measurement method as described in item 10 of the patent application scope further includes: replacing the light source to provide a third light beam and moving the object to be measured so that the focus of the third light beam is from the first surface of the object to be measured Transfer to the second surface of the object under test; detect the first light beam reflected by the object under test to obtain two third focus coordinates of the first surface and the second surface; and according to the two second The focus coordinate and the two third focus coordinates calculate an Abbe number of the object to be measured, wherein the wavelengths of the first beam and the third beam are different. The measurement method as described in item 11 of the patent application scope, wherein the measurement system further includes a temperature control module, and the measurement method further includes: measuring the object to be measured at different temperatures; and measurement based on different temperatures As a result, a refractive index change value of the test object at different temperatures is obtained.

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