JP2002372410A - Noncontact measurement apparatus using laser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve measurement resolution and sensitivity and monitor color images by changing the constitution of a color filter of an imaging device. SOLUTION: By arranging filters for receiving red light staggeredly and filters for receiving light with the other colors in between the filters for red light, the area of receiving red light is made larger than the area of receiving the other color.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact measuring device using a laser, and more particularly to a non-contact measuring device using a laser, which is suitable for use in a non-contact shape measuring device, a displacement meter, a dimension measuring device, and the like. The present invention relates to a contact measuring device and a color imaging device for receiving a laser beam, which is suitable for use in the contact measuring device.

[0002]

2. Description of the Related Art As shown in FIG. 1, a conventional filter for a color solid-state image sensor (hereinafter simply referred to as an image sensor) such as a CCD or a CMOS image sensor treats four pixels in a thick frame as pixels of one color. Normally, two pixels are used for a green (G) light receiving filter and a red (R) light receiving filter and a blue (B) light Only one pixel is used for each filter.

[0003]

However, only the one having a red (R) light receiving filter of one of the four elements is effective for receiving the red laser light generally used as the laser light. High resolution and sensitivity cannot be obtained.

On the other hand, if a white image sensor and a red hand-pass filter are used in combination instead of a color image sensor, all pixels can be used effectively, but data such as the color and shape of an object is lost, and measurement is not possible. There may be differences.
Further, in the case of natural light, fluorescent light, and the like, since most of the color components are included, if a bandpass filter is used, it may not be possible to determine whether the light is laser light.

The present invention has been made to solve the above-mentioned conventional problems, and it is a first object of the present invention to improve the resolution by increasing the number of red light receiving portions of a color image sensor.

Another object of the present invention is to reduce the influence of disturbance light based on color information obtained by a color image sensor.
Subject.

[0007] A third object of the present invention is to improve the detection accuracy by performing an appropriate correction based on data and color information by a laser beam.

A fourth object of the present invention is to make it possible to select an optimum laser beam.

[0009]

According to the present invention, there is provided a non-contact measuring device using a laser, comprising a color image pickup element in which the area of a red light receiving section is made larger than the area of each of the other color light receiving sections. This is a solution to the first problem.

The present invention also provides a color image pickup element capable of receiving three primary colors, wherein the area of the red light receiving section is larger than the area of each of the other color light receiving sections. Is what you do.

Further, by arranging more red light receiving filters than the other color light receiving filters, the area of the red light receiving portion is made larger than that of the other color light receiving portions only by changing the configuration of the color filters. It is.

Further, the red light receiving portions are arranged in a staggered manner, and the other color light receiving portions are arranged between the red light receiving portions.

According to another aspect of the present invention, there is provided a non-contact measuring device using a laser, wherein a color image pickup element capable of receiving three primary colors and an influence of disturbance light based on color information of each color detected by the color image pickup element. The second problem is solved by providing a means for removing the above.

The present invention also provides a color image pickup device capable of receiving three primary colors, and a color correction of a laser light image based on a change in color information of a measurement object detected by the color image pickup device due to the presence or absence of laser light. The above-mentioned third object has been achieved by providing means for performing the following.

The present invention also provides a laser light source capable of emitting a plurality of colors, a color imaging device capable of receiving three primary colors, and a laser light source based on color information of a measurement object detected by the color imaging device. By providing means for selecting a color, the fourth problem is solved.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

In the present embodiment, as shown in FIG. 2, light from a laser light source 10 applied to a measurement target 12 is received by a color image sensor 14, and edge extraction of the measurement target 12 and height or position information are performed. Applied when detecting.

Here, when the laser light source 10 is used as a surface light source having good coherence, the present invention can improve the edge extraction accuracy of the measurement object 12. When the laser light source 10 is used as a point light source focused on a surface to be measured, such as a displacement measuring device utilizing a technique of triangulation or an optical pickup, the object to be measured 12 Of the height or position information can be improved.

In this embodiment, the color image sensor 14
As shown in FIG. 3, instead of the general color filter as shown in FIG. 1, the green (G) light receiving filter and the red (R) light receiving filter are exchanged, and the red (R) light receiving filter is staggered. And a color filter having a green (G) light receiving filter and a blue (B) light receiving filter arranged therebetween.

Thus, the number of light receiving elements for red laser light is doubled only by changing the configuration of the color filter, and a resolution twice as high as that of a laser light image obtained by a normal color filter can be obtained. Further, a normal image and a laser light image can be obtained without a filter switching mechanism with one image sensor.

In the present embodiment, based on the color information obtained from the color image sensor 14, the influence of disturbance light is reduced as follows.

For example, when the intensities of red R, green G and blue B are all substantially equal (R ≒ G ≒ B), the laser light source 10
It is determined that the light is not ambient light but disturbance light such as natural light, and the data is excluded.

Alternatively, disturbance light is excluded from the intensity of red R by the following equation, and the intensity is corrected to R '.

R '= R-k (R + G + B) / 3 (1) where k is a variable.

Alternatively, in the RGB data, the laser light data is concentrated on the value of red R, so that conditions for excluding other combinations of values can be finely set to exclude disturbance light. For example, in general, when light amount detection using a red laser is performed, G (green) and B other than R (red)
(Blue) is not required. Therefore, G and B are usually cut by using a band pass filter. This can be said to be equivalent to setting G = B = 0 from the obtained data of RGB. However, in the case of white light such as a fluorescent lamp, all the color components are included, so that the R component still remains.

Therefore, normally, the white component is defined as R = G = B, the minimum value of R, G, and B is regarded as the white component, and the value is subtracted from the R component as shown in the following equation to obtain the white component. Get rid of.

R '= R-min [R, G, B] (2)

However, for example, G
When the component is present, it may not be sufficient to remove the white component. FIG. 4 shows the sensitivity of a general color image sensor. As can be seen from the figure, the sensitivities of the elements have such characteristics that they overlap each other and affect other components. Therefore, if G>R> B, G = B
After setting = 0, the peak component (here, G) is multiplied by a coefficient k and subtracted from the R component to reduce the influence from other components, as shown in the following equation.

R '= R-kG (3)

In the case of G>R> B, B is smaller than R, so the effect is small even if it is not reduced.

The above processing is performed by setting multi-stage conditions by software, and when high-speed data is required, the processing can be performed by hardware. Also, these can be combined or switched.

Specifically, in the case of a red laser, the processing as shown in FIG. 5 is performed for each data, and the values of j and k are changed depending on the state of the entire image (depending on the degree of luminance distribution around pixels) (1>). j>k> 0).

In this way, disturbance light such as natural light which cannot be removed by the red band filter can be accurately removed.

In the above description, only the acquired image is processed. However, by adding the parameters of the light projecting system and combining with the emission control of the laser light, a more accurate state of the laser light and the lighting of the laser can be achieved. The accuracy of data can be improved by detecting an image of an unmeasured object to be measured.

That is, as shown in FIG. 6, an image which does not use laser light is captured, and the data is compared with an image using laser light to reduce the influence of color data other than laser light.

More specifically, as shown in FIG. 7A, by subtracting the color information of the measuring object 12 obtained from the image data without laser light from the image data with laser light, other disturbance light can be obtained. And image data in which the influence of the color of the object to be measured is reduced.

If the S / N ratio of the R component is poor in the data, the S / N ratio is improved by increasing the amount of laser light. At that time, an increase in the amount of laser light causes
As shown in the above, when the light receiving element of the R component is saturated, the increase ΔR of the R component can be calculated based on the change ΔG of the G component as shown in the following equation.

ΔR = ΔG × k (4)

This is because, as is apparent from FIG. 4, the G component is also included in the R component.

Actually, for example, the measurement processing is performed after correcting the laser reflected light intensity of the color of each part of the measurement object 12 over the entire measurement range.

In this way, measurement errors due to the color of the object 12 can be reduced.

Further, as in the second embodiment shown in FIG. 8, various kinds of laser light sources (red light source 10R, green light source 10G, blue light source 10B) are used, and as shown in FIG. Is performed, the surface to be measured is not processed uniformly based on the color information of the image to be measured, but is switched to an optimal laser light source for each region, and a part of the image (for the selected data). Can be stored and combined with other stored image data to obtain a final measured image.

As described above, for example, in the case of a red laser, measurement of a red object to be measured cannot be performed with sufficient accuracy. The measurement of the object to be measured becomes possible.

The independent laser light source 10R for each color,
Instead of using 10G and 10B, it is also possible to use a white or multicolor (multicolor) laser light source whose color can be changed in combination with, for example, a filter or the like.

[0045]

According to the present invention, the area of the red light receiving section is
By making the area larger than the area of the other color light receiving sections, the resolution for the red laser can be improved.

Further, by removing the influence of disturbance light based on the color information of each color detected by the color image pickup device, disturbance light such as natural light which cannot be removed by the red band-pass filter can be removed.

Further, by correcting the color of the laser light image based on a change in the color information of the measurement object due to the presence or absence of the laser light, which is detected by the color image sensor, errors due to the color of the measurement object can be reduced.

By selecting the color of the laser beam based on the color information of the object to be measured detected by the color image pickup device,
It has excellent effects such as measurement of a measurement object that has been impossible in the past.

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration of a conventional color filter used in a color image sensor.

FIG. 2 is a schematic diagram showing a basic configuration of a non-contact measuring device to which the present invention is applied.

FIG. 3 is a plan view showing a configuration of a color filter used in an embodiment of the color imaging device according to the present invention.

FIG. 4 is a diagram illustrating spectral characteristics of a general color image sensor for explaining the principle of the present invention.

FIG. 5 is a flowchart showing a procedure of disturbance light removal processing in the embodiment of the present invention.

FIG. 6 is a flowchart showing processing according to the presence or absence of a laser beam.

FIG. 7 is a schematic diagram of the same.

FIG. 8 is a block diagram showing a configuration of a second embodiment of the present invention.

FIG. 9 is a flowchart showing a processing procedure according to the second embodiment;

[Explanation of symbols]

 10, 10R, 10G, 10B: Laser light source 12: Object to be measured 14: Color image sensor

Claims (7)

[Claims] 1. A non-contact measuring device using laser light, comprising: a color imaging element in which the area of a red light receiving section is larger than the area of each of the other color light receiving sections. 2. A color image pickup device for receiving laser light, wherein the color image pickup device capable of receiving three primary colors has an area of a red light receiving portion larger than an area of each of the other color light receiving portions. 3. The red light receiving filter according to claim 2, wherein an area of the red light receiving portion is larger than an area of each of the other color light receiving portions by disposing more red light receiving filters than the other color light receiving filters. Color imaging device for laser reception. 4. The laser receiving device according to claim 2, wherein the red light receiving portions are arranged in a staggered manner, and the other color light receiving portions are arranged between the red light receiving portions. Color image sensor. 5. A color image pickup device capable of receiving three primary colors, and means for removing the influence of disturbance light based on color information of each color detected by the color image pickup device. Non-contact measuring device using laser. 6. A color imaging device capable of receiving three primary colors, and means for performing color correction of a laser light image based on a change in color information of a measurement object due to the presence or absence of laser light, detected by the color imaging device. A non-contact measuring device using a laser, comprising: 7. A laser light source capable of emitting a plurality of colors, a color imaging device capable of receiving three primary colors, and selecting a color of the laser light based on color information of a measurement object detected by the color imaging device. A non-contact measuring device using a laser, comprising: