JPH03267708A - Binary distance image sampling device - Google Patents

Abstract

PURPOSE:To properly sample a binary distance image by using discrete spectral light beams with >=3 wavelengths, focusing one wavelength light beam on a binary distance reference surface, and detecting the direction of a shift with other wavelength light beams. CONSTITUTION:A three-wavelength (RGB) light source 1 provides uniform lighting with scattered light; and only the light which has a wavelength G as to light from a point (a) on a ceramic substrate 13 to be measured is focused on a point a' on a single-plate color CCD 3 and neither of light beams having wavelengths R and B is focused because of a high-dispersion lens 2. The light having the wavelength B from a point (b) above the binary distance image reference surface of the substrate 13 is focused on a point b' on the CCD 3 and the light beam having the wavelength R from a point (c) is focused on a point c'. For the purpose, it is judged whether the defocusing of the light with the wavelength G is near of far by looking at the focusing states of the wavelengths R and B to obtain the binary distance image.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a binary distance image acquisition device, and particularly to a binary distance image acquisition device for acquiring a binary distance image used when inspecting the mounting state of components. Regarding equipment.

[Conventional technology]

Conventionally, this type of planar (two-dimensional) range finder is a rainbow range finder, interferometry, or optical probe.

There are distance meters that use triangulation.

[Problem to be solved by the invention]

The conventional binary distance image acquisition device described above is basically only for obtaining distance images, and in order to obtain only binary distance images, more data than necessary is obtained, resulting in excessive measurements. The problem is that this is done.

Furthermore, each method has the following problems.

With interferometry, measurements can be made in wavelength units, but ■0, 1
2.m laser beams do not exist, 1) parts with missing interference fringes are likely to occur, 2) it depends on the color and surface texture of the target object, so it is difficult to mount components on printed circuit boards, ceramics, or substrates. Not suitable for confirmation.

In addition, with the rainbow range finder, ■Due to the triangulation of species, shadow areas are likely to occur during component mounting, making it difficult to interpolate between them.■The amount of irradiation light cannot be increased too much. highly influenced by color,
It is quite unsuitable because it may not be possible to get a signal.

Furthermore, Metshi projection method, multi-light cutting method, etc. can be considered, but distance data can only be obtained in a very rough manner.

On the other hand, the triangulation method using a laser spot or the light cutting method using a laser slit light can be used to perform point or line measurement, but these methods tend to create shadows and take time to measure. There is a drawback that it takes a long time.

[Means to solve the problem]

The binary distance image acquisition device of the present invention includes a mechanism for acquiring an image using discrete spectrum light of three or more wavelengths using an optical system that focuses on different positions depending on the wavelength, and a mechanism for calculating corresponding points for images at each of the wavelengths. and a mechanism for evaluating the degree of focus matching.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 μ is a sectional view of a camera used in the present invention.

2 in Fig. 1, uniform illumination is performed using scattered light from a three-wavelength light source 1 having a discrete spectrum with multiple wavelengths (ζ几GB wavelength in this figure), that is, three single wavelengths with different wavelengths, so as not to cause shadows. conduct. Ceramic battery board 13 which is the object to be measured
For the light from point a, due to the high dispersion lens 2, a' is correct only for the wavelength G, and a' is placed on the single-plate color CD3.
focus as follows. On the other hand, at this time, the wavelengths of 几 and B are not in focus correctly. Further, a point on the ceramic backing board 13 that is above the second distance image reference plane 4 is focused at wavelength B on the single-plate color CCD 3 as b'. Similarly, for C, the wavelength filter focuses as C'.

FIG. 2 shows the above more schematically.

However, although it is written here as if the position of the focus plane is changing, in reality, the distance to the object side changes, so the relative position between the focus plane (the surface where the two CODs exist) and the actual focus position only has meaning.

Here, whether the focus shift of G is near or far is determined by R,
A binary distance image can be obtained by checking the in-focus state of H. Here, the position of each of the focusing reference planes 4 to 6 depends on the high dispersion lens 2. For this reason, the necessary distance comparison area 7 is obtained by combining the dispersion performance of the lens and the wavelengths used.

Note that if a sufficient size cannot be obtained with three wavelengths, it is possible to cope with this by increasing the number of wavelengths.

In the type shown in FIG. 1, adjustment is difficult because it involves lens dispersion, changing the wavelength, etc.

On the other hand, the image shift for each wavelength is small, and the calculation of corresponding points may be made to correspond approximately to the address of the captured image.

Next, FIG. 3 shows a sectional view of another type of camera used in the present invention. It is basically an RGBB board type color camera, and 8 and 9 are CCDs corresponding to each color. The lens IO used is a super achromatic lens for three colors, that is, a plan achromat type lens. CC for B
Microstages 11 and 12 for device position adjustment are attached to the D9 and R CCDs 9, respectively.

In this case, this microstage allows R2O, B
Since the relative focus matching reference plane for each color can be adjusted, there is an advantage that the distance comparison possible area 7 can be easily adjusted.

FIG. 4 shows the overall system configuration of the embodiment.

Ceramic board 1 with target chip components mounted on it
3, a three-wavelength light source 1 having a discrete spectrum performs scattering illumination. This is imaged by the RGB camera 14, and R,G
, B are stored in the multilevel video memo IJ 15. Next, each image is passed through a local multi-value processing processor 16 to create a focus matching degree image including "unknowns" from each surrounding pixel for each color, and storing it in a focus matching degree image memory 17.

Distance determiner 18vi accesses each focus matching degree image memory 17 via an address converter 19 having an address conversion function for calculating correspondence degree, and stores the obtained binary distance image in binary distance image memory 2o. That is, the address converter 19 converts the address (x, y) to the image memory center (XC).

Yc) and the constant CR9CG (=
1), with CB, x'=(X-Xc)-C,,+x
c, Y'=(Y-yc)-CR+yc and magnification adjustment is performed.

Moreover, the binary distance image is more precisely a 31-section image in which a region of 9 "unknown" exists in addition to 0.1.

〔Effect of the invention〕

As explained above, the present invention is capable of focusing one wavelength on a binary distance reference plane by using discrete spectrum light of three or more wavelengths, and is capable of focusing one wavelength on a binary distance reference plane.
Since it is possible to measure the direction in which light of wavelength or longer is shifted by surface measurement, it is possible to easily collect appropriate 21 [distance images].

Further, by increasing the number of wavelengths and changing the focus position at each wavelength, there is an effect that a binary distance image can be obtained at high speed.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a camera used in the present invention, Fig. 2a is a schematic diagram thereof, Fig. 3 is a sectional view of another type of camera used in the present invention, and Fig. 4 is a sectional view of an embodiment of the present invention. This is a professional drawing. 1...3 wavelength light source (几GB), 2...
High dispersion lens, 3...Flat type color CCD, 4
... Binary distance image reference plane (G focus matching reference plane), 5... General focusing reference plane, 6...
... B focus matching reference plane, 7... Distance comparison possible area, 8... CCD for G (fixed), 9-.
- CCD for R and B, 10. '゛°°super-colored lenses,
ll-°°...Microstage, 12...
Microstage, 13... Ceramic board,
14...RGB camera, 15...Multi-level video memo! J, 16°°°...Local multivalue processing processor, 17°°°°"°focus degree image memory,
18...Distance determiner, l9-°-゛address converter, 2o...Binary distance image memory.

Claims (1)

[Claims] It has a mechanism that collects images with discrete spectrum light of three or more wavelengths using an optical system that focuses on different positions depending on the wavelength, and a mechanism that calculates corresponding points for images at each of the wavelengths and evaluates the degree of focus. A binary distance image acquisition device characterized by: