TWI391623B - Measuring device and measuring method - Google Patents

Description

Measuring device and measuring method

The present invention relates to a measuring device and a measuring method, and more particularly to a measuring device and a measuring method for measuring surface characteristics having high reflectivity.

In the technique of measuring surface characteristics, general mechanical contact measurement methods (such as comparative measurement, probe type measurement, capacitance measurement, and radioisotope measurement) can meet the measurement standard and accuracy of demand. However, because the measurement speed is slow, and the surface to be measured is directly damaged by the contact force. Therefore, in recent years, the non-contact measurement method based on optical measurement technology has flourished. The measuring device using the non-contact measuring method has the advantages of fast measuring speed, avoiding damage to the surface to be tested, good stability and reliability, and has been widely used in high-precision metrology. According to its application mode, optical measurement technology can be divided into passive measurement and active measurement.

Passive measurement requires multiple sets of cameras to capture images of the same surface to be tested through different viewing angles, and then combines image processing to generate a geometric model of the surface to be tested, and obtains surface characteristics by geometric model calculation. The measurement device of this type is complicated in structure and complicated in measurement steps, and can not effectively improve the measurement accuracy, so it is less used by the industry.

In addition, in the active measuring method, the structured light of the laser light or the known pattern is projected on the surface to be tested at a known angle, and the light pattern on the surface to be tested is obtained by the camera toward the surface to be tested. By analyzing the surface to be tested The light pattern obtains the surface characteristics of the surface to be tested. However, when measuring the surface of high reflectivity, the difference in the contrast of the light patterns obtained by the camera is low, which greatly affects the accuracy of the measurement, so that the application of the measuring device is limited.

Therefore, how to effectively measure the surface characteristics of the high-reflection surface to be tested is one of the problems to be solved at present.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a measuring device and a measuring method for measuring surface characteristics of a surface to be tested having high reflectance.

According to the above object of the present invention, a measuring device is provided, comprising a housing, a light source, an imaging screen and an image capturing unit. The light source is disposed in the housing for projecting a light beam, and the light beam is projected to the surface to be tested through an opening of the housing, and is reflected and projected onto the image forming screen. The imaging screen is disposed in the housing, and the beam reflected by the surface to be tested forms an image on the imaging screen. The image capturing unit is disposed in the housing for capturing an image formed on the image forming screen.

According to another object of the present invention, a method of measuring high reflectivity surface characteristics is proposed, first to project a light beam toward a surface to be tested. Then, the projected beam reflects one of the images through the surface to be tested to an imaging screen. Second, capture the image on the screen. Then, by analyzing and calculating the captured image by the arithmetic unit, one surface characteristic of the surface to be tested can be obtained.

After the light beam projected by the light source of the present invention is reflected, it is first imaged on the image forming screen, and then the image capturing unit is used to image the image on the screen. Take the image. In this way, the contrast difference of the captured image can be improved, and the image discrimination degree is improved, and the measurement accuracy is further improved. In addition, the light source, the imaging screen and the image capturing component are disposed in the housing, which can improve the integration and portability of the measuring device.

According to the measuring device and the measuring method of the preferred embodiment of the present invention, the surface characteristic measurement of the surface to be tested is measured by capturing the image formed by the reflected light beam, thereby improving the image contrast difference and improving the surface characteristic amount. The accuracy of the measurement.

First, a measurement apparatus according to a preferred embodiment of the present invention will be described. Please refer to FIG. 1 , which is a perspective view of a measuring device according to a preferred embodiment of the present invention. The measuring device 100 is configured to measure a surface S to be tested. The measuring device 100 includes a housing 101, a light source 103, an imaging screen 105, and an image capturing unit 107. The housing 101 has an opening 101a. The light source 103 is disposed in the housing 101 for projecting a light beam L. The light beam L is projected through the opening 101a to the surface S to be tested, and the surface S to be measured reflects the light beam L. The image forming screen 105 is disposed in the casing 101, and an image P is formed on the image forming screen 105 by the light beam L' reflected by the surface S to be tested. The image capturing unit 107 is disposed in the casing 101 for capturing the image P formed on the image forming screen 105. The measuring device 100 measures a surface characteristic of the surface to be tested S based on the captured image P.

Furthermore, the imaging screen 105 is disposed on an inner side surface of the housing 101 with respect to the light source 103. In various embodiments, the housing 101 The inner surface of the light source 103 can be used as the image forming screen 105 for forming the image P. The measuring device 100 and the measuring method of the preferred embodiment of the present invention are characterized in that the projected image is captured relative to the surface of the object to be directly measured by the appropriate reflection distance from the opening 101a to the imaging screen 105. The image P of the reflection is extracted and analyzed by the formula, the contrast difference of the captured image P can be improved, and the discrimination of the image P of the surface S to be measured at different levels can be improved, thereby improving the measurement accuracy. The measuring device 100 further includes a lens 109 disposed between the light source 103 and the opening 101. In this embodiment, the light source 103 is, for example, a sector-shaped laser light generator, and the light beam L projected by the light source 103 is a sector-shaped laser light, and is preferably high-monochromatic, high-brightness, and single-line type light. When the light beam L penetrates through the lens 109, it is refracted by the lens 109 into parallel light, so that the light beam L is projected to the surface to be tested and reflected to the image forming screen 105 to form the image P, which maintains the same width, so as to facilitate the same width. Subsequent calculations.

In addition, the measuring device 100 further includes at least one mask for improving the quality of the captured image P. As shown in FIG. 1 , the measuring device 100 of the embodiment further includes a first mask 111 or/and a second mask 112 . The first mask 111 is disposed between the light source 103 and the opening 101a. In more detail, the first mask 111 of the embodiment is disposed between the light source 103 and the lens 109. The first mask 111 is used to filter out the excess fan beam to avoid causing the scattered beam to increase the brightness or secondary reflection inside the casing 101, thereby improving the quality of the image capturing unit 107. The second mask 112 is disposed between the light source 103 and the port 101a. More specifically, the second mask 112 of the present embodiment is disposed between the lens 109 and the opening 101a. The second mask 112 is used to homogenize the light beam L to improve the quality of the image on the imaging screen 105. This implementation In the example, the first mask 111 and the second mask 112 are described. However, those skilled in the art to which the present invention pertains can understand that the configuration of the mask is not limited thereto. For example, the measurement device 100 may include only one of the first mask 111 and the second mask 112, or include more masks, such as a third mask. The third mask may be disposed between the light source 103 and the opening 101a for patterning the light beam L and forming a structured light, thereby further enhancing the discrimination of the change of the reflection characteristic of the light beam L' reflected by the surface S to be tested. In addition, the second mask 112 may also be disposed on the inner side surface of the housing 101 corresponding to the opening 101a to simplify the structure of the measuring device 100.

In another aspect, the measuring device 100 further includes an arithmetic unit. Please also refer to FIG. 2, which shows a functional block diagram of the measuring device of FIG. 1. The operation unit 115 is connected to the image capturing unit 107 for receiving the captured image P, thereby calculating and analyzing the surface characteristics of the surface S to be tested. In an embodiment, the computing unit 115 can be a computer (such as a notebook computer) and connected to the image capturing unit 107 by using a high speed communication protocol (such as GigaEByte). In this embodiment, the image capturing unit 107 is a Charge-Coupled Device camera. However, the image capturing unit 107 is not limited thereto, and other components that can capture the image P on the imaging screen 105 can be applied thereto.

The measuring device 100 further includes a power source 113. As shown in FIG. 1 and FIG. 2, the power source 113 is connected to the light source 103 and the image capturing unit 107 for supplying electric power. In the embodiment, the power source 113 is disposed outside the casing 101. However, in different embodiments, the power source 113 may be disposed in the casing 101 to improve the integration of the measuring device 100.

In practical applications, in the measuring device 100 of the embodiment, the light source 103 The projected fan-shaped laser beam L passes through the lens 109 to form parallel light and is projected onto the surface S to be tested. Then, the light beam L is reflected by the surface S to be measured, and the reflected light beam L' forms an image P on the image forming screen 105. After the light beam L is projected on the surface S to be tested, the light beam L projected at different positions changes due to the height of the surface S to be measured, so that the reflected light beam L' has different reflection characteristics such as line width and contour change. Then, the image P is captured by the electric coupling element camera. After the image unit P captures the image P, the analysis and calculation of the line width of the light beam L' and the contour of the center line are performed to quantify the surface characteristics of the surface S to be tested, including surface roughness, surface ripple, and surface thread printing. Before the light beam L is projected onto the surface S to be tested, it may be advantageously passed through the first mask 111, the second mask 112 or/and the third mask to filter out the scattered light beam and homogenize the light beam L passing through the lens 109. And patterning the light beam L and forming structured light.

Hereinafter, a method of measuring the surface characteristics of high reflectance according to a preferred embodiment of the present invention will be described. Please also refer to FIG. 3, which illustrates a flow chart of a measurement method in accordance with a preferred embodiment of the present invention. First, as shown in step S1, the light beam L is projected toward the surface S to be tested. In this embodiment, the light source 103 is applied to project a fan-shaped laser light. The light beam L is projected through the opening 101a of the casing 101 to the surface S to be tested. Next, in step S2, the image P of the projected light beam L reflected by the surface to be tested S is projected onto the image forming screen 105. Then, the step of capturing the image P on the imaging screen 105 is performed as shown in step S3. In this embodiment, the image capturing unit 107 is used to capture the image P formed on the imaging screen 105. Then, step S4 is executed, and according to the image P, the image P of the surface to be tested is obtained by analyzing and calculating the captured image P by the operation unit 115. In this embodiment, an arithmetic unit connected to the image capturing unit 107 is applied. 115 performs an operation to obtain surface characteristics such as surface roughness, surface waviness, and surface thread printing of the surface S to be tested.

Furthermore, the measuring method of the surface to be tested of the embodiment further includes the step of focusing the light beam L to form the light beam L into parallel light. In the measuring device 100, a lens 109 is applied to focus the light beam. In addition, the measuring method of the surface S to be tested in this embodiment may further include the steps of filtering out the scattered light beam L, the step of homogenizing the light beam L, and the step of patterning the light beam L. In this embodiment, the first mask 111 is used to filter out the excess fan beam in the measuring device 100 to reduce the influence of the scattered light beam L in the casing 101 on capturing the image P, and the second mask 112 is Used to homogenize the beam L to improve the quality of the image. The third mask is used to pattern the light beam L to form structured light, which can further enhance the discrimination of the change of the reflection characteristic of the light beam L', and is more beneficial for subsequent operations after capturing the image P.

According to the preferred embodiment of the present invention, by using the image captured on the image screen, the reflected image can be captured for the surface with high reflectivity, and the image with large contrast is obtained, which improves the measurement accuracy. The advantage of degree. In addition, by integrating the main components in the casing, the volume of the measuring device can be effectively reduced, and the portability is improved. Furthermore, as long as the light beam can be measured by being reflected onto the image forming screen through the surface to be tested, the measuring device can be set on a large area to be tested, and the surface to be tested can be cut without being tested, and can be applied to The surface to be tested with various tilt angles enhances the convenience of measurement and the range of applications.

Although the present invention has been described above in terms of a preferred embodiment, it is not intended to limit the invention, and it is obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. Invention The scope of protection is subject to the definition of the scope of the patent application attached.

100‧‧‧Measurement device

101‧‧‧shell

101a‧‧‧ openings

103‧‧‧Light source

105‧‧‧Image screen

107‧‧‧Image capture unit

109‧‧‧ lens

111‧‧‧First mask

112‧‧‧ second mask

113‧‧‧Power supply

115‧‧‧ arithmetic unit

L‧‧‧beam

L’‧‧‧ Beam

P‧‧‧ images

S‧‧‧ surface to be tested

The above and other objects, features, advantages and embodiments of the present invention will become more apparent and understood.

1 is a perspective view of a measuring device in accordance with a preferred embodiment of the present invention.

FIG. 2 is a functional block diagram of the measuring device of FIG. 1.

FIG. 3 is a flow chart showing a measurement method according to a preferred embodiment of the present invention.

100‧‧‧Measurement device

101‧‧‧shell

101a‧‧‧ openings

103‧‧‧Light source

105‧‧‧Image screen

107‧‧‧Image capture unit

109‧‧‧ lens

111‧‧‧First mask

112‧‧‧ second mask

113‧‧‧Power supply

115‧‧‧ arithmetic unit

L‧‧‧beam

L’‧‧‧ Beam

P‧‧‧ images

S‧‧‧ surface to be tested

Claims (7)

A measuring device for measuring a surface to be tested, the measuring device comprising: a housing having an opening; a light source disposed in the housing for projecting a light beam, the beam is projected through the opening To the surface to be tested, wherein the light source is a sector-shaped laser light generator, the light beam is a fan-shaped laser light; a lens is disposed between the light source and the opening, and the light beam passing through the lens is parallel light; a first mask disposed between the light source and the opening for filtering out excess scattered light beam; a second mask disposed between the light source and the opening for homogenizing the light beam; a three-mask, disposed between the light source and the opening, for patterning the light beam to form a structured light; an imaging screen disposed in the housing, the light beam reflected by the surface to be tested forms an image And an image capturing unit disposed in the housing for capturing the image; wherein the measuring device obtains a surface characteristic of the surface to be tested according to the captured image. The measuring device of claim 1, wherein the measuring device further comprises: an computing unit connected to the image capturing unit for receiving the captured image, and analyzing and calculating the image With this image, the surface characteristics of the surface to be tested can be obtained. The measuring device of claim 2, wherein the computing unit is a computer. The measuring device of claim 1, wherein the measuring device further comprises: a power source connected to the light source and the image capturing unit for providing power. The measuring device of claim 1, wherein the image capturing unit is a Charge-Coupled Device camera. The measuring device according to claim 1, wherein the surface characteristic comprises at least surface roughness, surface waviness and surface thread printing. A method for measuring surface characteristics of high reflectivity includes: projecting a light beam toward a surface to be tested; projecting the image of the light beam reflected by the surface to be tested and projecting on an image forming screen, wherein a sector-shaped laser light generator is used Generating the beam, the beam being a sector of laser light; focusing the beam to form parallel light; filtering out the excess scattered beam; homogenizing the beam; patterning the beam to form a structured light; capturing the image The image on the screen; and obtaining a surface characteristic of the surface to be tested according to the image.