JPH0554882B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a surface texture measuring device, and in particular, the flatness and glossiness of a coating film, painted surface, or other sample surface to be measured, such as waviness or orange skin. The present invention relates to a device for measuring.

[Conventional technology]

As an apparatus for measuring the flatness of a paint film or a painted surface, for example, Japanese Patent Application Laid-open No. 76004/1983 is known. This device consists of a light source, a bright/dark pattern, an imaging lens, a photoelectric conversion element, etc., and measures the flatness based on the distortion rate.

On the other hand, regarding the glossiness of the sample surface to be measured, JIS
Measurement devices compliant with Z8741 are commercially available from various companies.

[Problem that the invention seeks to solve]

Conventionally, when attempting to measure the flatness and glossiness of a surface of a sample to be measured, it has been necessary to prepare a separate flatness measuring device and a glossiness measuring device, respectively, resulting in a long measurement time.

Furthermore, it has been difficult to quantitatively evaluate the flatness and glossiness at the same position on the surface of a sample to be measured because the conditions for mounting the sample on each measuring device vary.

An object of the present invention is to provide a surface texture measuring device that can simultaneously measure flatness and gloss by mounting a sample once.

[Means for solving problems]

In order to achieve the above object, the present invention includes a light source, a grating that is placed close to the light source and repeats brightness and darkness repeatedly, and a real image of the grating after the light transmitted through the grating is reflected onto the surface of a sample to be measured. a photoelectric exchange unit installed on the imaging plane of the grating image by the lens and photoelectrically converting the light intensity distribution of the grating image, and detecting the pitch Pi of the grating image based on the conversion signal from the photoelectric conversion unit. , standard deviation σ of pitch Pi The pitch signal processing circuit outputs the flatness of the sample surface to be measured, and the contrast C is calculated from the bright part voltage VBi and the dark part voltage VDi of the grating image based on the conversion signal from the photoelectric conversion unit. × _o 〓 We proposed a surface texture measuring device consisting of a contrast signal processing circuit that calculates ⁱ⁼¹ VBi−VDi/VBi+VDi and converts it into the glossiness of the sample surface to be measured, and a display unit that displays the flatness and glossiness. It is something to do.

[Effect]

In the present invention, the bright and dark pitch and contrast are extracted from the photoelectric conversion signals of the same part of the mounted sample surface, the flatness is determined based on the pitch, and the contrast is converted into glossiness. The flatness and glossiness of the same area can be measured.

〔Example〕

FIG. 1 is a block diagram showing the configuration of an embodiment of a surface texture measuring device according to the present invention. In the figure, a light source holder 1 holds a light source 2 such as a tungsten lamp or a halogen lamp. A set of two condenser lenses 4 is attached to the light projection holder 3.
, a diffuser plate 5 made of frosted glass or opal glass, and a grid 6 in which light and dark are alternately repeated. As shown in FIG. 2, the grating 6 has a dark grating 101 of W1 = 0.1 mm, which is chromium-deposited or aluminum-deposited on a glass substrate 100, and a bright grating 102 of W2 = 0.1 mm, which is not vapor-deposited, at the same pitch. It is a grid that is repeated alternately over a length of approximately 10 mm. The projection lens 8 mounted on the lens holder 7 includes optical path bending mirrors 9, 10, 1
1 and the sample surface 13, the linear CCD 1
This is a lens that forms a grating image on 5. The linear CCD 15 is mounted on the CCD holder 14,
It is located at the imaging plane of the lattice image and photoelectrically converts the lattice image. Reference numeral 12 denotes a permanent magnet for sample attraction that fixes the sample in a predetermined position.

The analog signal generated in the linear CCD15 is
Via the high pass filter 16 and amplifier 17,
The signal is input to the A/D converter 18. The A/D converter 18 converts the output signal of the amplifier 17 into a CCD
In response to an AD/D conversion start signal from the control circuit 20, analog/digital conversion is performed successively, and the photoelectric conversion waveform of the grating image is stored in the memory circuit 19. 20 is a CCD that drives the linear CCD 15
a control circuit; 21 is a central processing unit (CPU) that controls the entire measuring device; 22 is a display that displays the results of flatness and gloss calculated by the CPU 21;
3 is a measurement switch.

The operation of the surface texture measuring device of the present invention constructed as described above will be explained next. Here, the projection lens 8
The focal length of is 50mm, the distance from grating 6 to projection lens 8 is 60mm, and from projection lens 8 to linear CCD
Assume that the distance to No. 15 is 300 mm and the projection magnification is 5x.

The light beam from the light source 2 is condensed by two condenser lenses. The condensed luminous flux passes through the diffuser plate 5
This results in a uniform intensity distribution and illuminates the grating 6. Therefore, the projection lens 8 forms a real image of the grating 6 by focusing the light that has passed through the grating 6 on the linear CCD 15 via the optical path bending mirrors 9, 10, 11 and the sample surface 13.

When the sample is a plane mirror, when the plane mirror is held by the sample adsorption permanent magnet 12, the grating image is enlarged and projected five times, and a continuous image of brightness and darkness with a pitch of 0.5 mm without distortion is formed on the linear CCD 15. be done.
The output signal photoelectrically converted by the CCD 15 is as shown in Fig. 3, and is sent to the next stage high-pass filter 16.
sent to. The high-pass filter 16 filters ambient light such as sunlight and indoor lighting into the linear CCD 1.
5, the low frequency signal superimposed on the output signal of the linear CCD 15 is removed. The output signal of the high-pass filter 16 is amplified by the amplifier 17,
The signal is input to the A/D converter 18. In the A/D converter 18, the signal of the grating image photoelectrically converted by the linear CCD 15 is sent to the CCD control circuit 20.
Analog quantities are successively converted into digital quantities in synchronization with the timing signal created by The converted digital value is stored in memory circuit 19. In the case of this embodiment, a linear CCD with a resolution of 2048 is used, digital conversion is performed by a 12-bit A/D converter 18, and the memory circuit 19
It is designed to be able to store 2048 x 12 bits of data.

When the measurement switch 23 is pressed, the CPU 21 recognizes this and stores the lattice image data of the surface 13 of the sample to be measured in the memory circuit 19. The CPU 21 reads the data stored in the memory circuit 19, and reads the peak points B31, B32, B33, . . . in the bright portions of FIG.
...or the bottom points D31, D32, D33 of the dark area
Extract... Next, the pitches P31 and P32 are extracted (in this embodiment, the pitches are obtained from the number of addresses between the bottom points). The standard deviation σ is calculated from this pitch data.

The calculated standard deviation σ is displayed on the display 22 as the flatness of the sample surface 13 to be measured.

On the other hand, the extracted peak point and bottom point voltages VB1, VB2, VB3, ... and VD1, VD2,
From VD3, . . . , calculate the contrast C of the relevant sample surface portion using the following formula.

C=1/n _o 〓 ⁱ⁼¹ VBi−VDi/VBi+VDi The calculated contrast is converted into glossiness and displayed on the display 22 in the same way as the flatness.

In the above explanation, the sample was a plane mirror, but the same applies to the case of a coating surface. Figure 4 shows the output signal obtained from the linear CCD 15 due to reflection on the coating surface. In this case, unlike the example of the plane mirror in FIG. 3, the output waveform is disturbed by the undulations or orange skin of the surface of the sample to be measured, and the peak points B41, B42, etc.
B43... and bottom points D41, D42, D4
Since the location of 3... is also a ward, Pituchi P41,
P42, P43... are also irregular.

Although the above embodiment uses a linear CCD, a combination of a linear CCD and a feeding mechanism or an area CCD may be used instead. At that time, the CCD control circuit 20 scans not only in the direction in which the linear CCDs are arranged, but also in a direction perpendicular thereto.

Similarly to the above embodiment, the CPU 21 calculates the standard deviation σi and contrast Ci on each scanning line, then calculates their average values σ and C, and displays the flatness and glossiness of the sample surface to be measured on the display 22. to be displayed.

The present invention not only measures the flatness and gloss of the waviness or shaking surface of a paint film or painted surface, but also measures
It can also be used to measure the waviness of metal surfaces, plastic surfaces, etc., and its range of applications is wide.

[Effects of the Invention] According to the present invention, by simply mounting the sample once,
A surface texture measuring device capable of simultaneously measuring flatness and gloss of a surface of a sample to be measured is obtained.

Therefore, operation is simple, measurement time is short,
It is also advantageous to apply to automated production lines.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the structure of an embodiment of the surface texture measuring device according to the present invention using a linear CCD, Fig. 2 is a diagram showing the structure of the grating of the device shown in Fig. 1, and Fig. 3 is a diagram showing the sample surface. Linear shape when is a plane mirror
A diagram showing the output waveform of the CCD. FIG. 4 is a diagram showing the output waveform of the linear CCD when the sample surface is a painted surface. 2...Light source, 4...Condenser lens, 5...
Diffusion plate, 6... Grid, 8... Projection lens, 9, 1
0, 11...Bending mirror, 12...Permanent magnet for sample attraction, 13...Sample, 15...Linear type
CCD, 16...High pass filter, 17...Amplifier, 18...A/D converter, 19...Memory circuit, 20...CCD control circuit, 21...CPU,
22...display, 23...switch.

Claims (1)

[Scope of Claims] 1. A light source, a grating that is placed close to the light source and repeats brightness and darkness many times, and a real image of the grating is formed after the light transmitted through the grating is reflected onto a surface of a sample to be measured. a photoelectric conversion unit installed on an imaging plane of the grating image by the lens and photoelectrically converting the light intensity distribution of the grating image; and detecting a pitch Pi of the grating image based on a conversion signal from the photoelectric conversion unit. and the standard deviation σ of the pitch Pi and a pitch signal processing circuit which calculates the flatness of the sample surface to be measured, and calculates the contrast C from the voltage VBi of the bright part and the voltage VDi of the dark part of the grating image based on the conversion signal from the photoelectric conversion unit. /n× _o 〓 ⁱ⁼¹ A surface texture measurement consisting of a contrast signal processing circuit that calculates VBi−VDi/VBi+VDi and converts it into the glossiness of the sample surface to be measured, and a display unit that displays the flatness and glossiness. Device.