JPH1038521A - Three-dimensional measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the picture-processing speed of a three-dimensional measuring instrument with two photoreceptor elements by using the time difference between them by utilizing the fetching time of one of the elements by switching the optical paths of the elements to each other by rotating a mirror or using an optical switch, liquid crystal, etc. SOLUTION: The three-dimensional measuring instrument has two CCD devices 1 and 2 as photoreceptor elements. A picture made incident on a lens system 3 forms an image in the CCD device 1 when a shutter 4 is not pulled down. The optical path is switched to the CCD device 2 with the shutter 4 and a mirror 5 by closing the shutter 4 having a mirror function while the CCD device 1 process the optical information. When the device 2 fetches a picture, the shutter 4 is opened so that the picture can be displayed on the device 1. Therefore, the information processing time of the measuring instrument can be shortened by utilizing the response time of the CCD devices. In addition, the switching time between the two CCD devices 1 and 2 is synchronized by a CPU.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a three-dimensional measuring device.

[0002]

2. Description of the Related Art As a conventional three-dimensional measurement technique, a light-section method is described in detail in the IEICE Transactions May, 1985, "Real-Time Distance Detector Using Light-section Method". As the light receiving unit, those using a CCD or a PSD element are known. Among them, the PSD is ITEJ TEC.
HNICAL REPORT Vol. 14 No. 49
"High-speed three-dimensional measurement by light-section method and its application", IEICE Transactions, Vol. J72-D "Proposal of high-speed range finder" has a detailed description.

[0003] CCDs are most often used. As a document, JP-A-63-26523 "Signal processing method of compound eye range finder device" describes that accurate spatial coordinates can be obtained by using a plurality of cameras and slit light without being influenced by a background scene. ing. In addition, in Japanese Unexamined Patent Application Publication No. 3-269205 “Non-contact three-dimensional shape measuring device”, an independent photo sensor PD is placed on a light receiving unit,
Each PD is provided with a processing circuit to increase the speed.

[0004]

As described above, the conventional 3
Many of the dimension measuring devices use a CCD or a PSD as a light receiving unit.

However, when a CCD or PSD is used for the light receiving section, both have the following disadvantages. (1) When a CCD device is used as the light receiving unit, the response time of the CCD device is slow, and it takes a long time to take in information, and a considerable time is required until image processing is performed. There is a drawback that increasing the resolution further reduces the speed.

(2) When a PSD device is used for the light receiving section, the response speed of the PSD device is much higher than that of the CCD, and it takes less time to capture information, but the resolution is lower. When the resolution is increased, there is a disadvantage that the arrangement of the elements is increased in density, which is technically difficult.

(3) Further, if a number of signal processors are provided in the light receiving section, it is necessary to integrate the image pickup device into an IC, which requires advanced technology.

An object of the present invention is to provide a three-dimensional measuring device which solves these problems and improves the image processing speed.

[0009]

In order to solve the above-mentioned problems, the present invention utilizes a capture time by rotating a mirror, switching an optical path by an optical switch or a liquid crystal, and using a time difference. The information processing is performed by the light receiving elements.

One is to rotate a mirror to deflect an optical path, and the other is to use an optical switching element.

In a three-dimensional measuring apparatus for receiving an image through a lens by a light receiving means and performing image processing, two CCDs for light reception are used, and a mirror provided between the lens and each CCD is rotated to emit light. And the other CCD captures an image during the processing time of one CCD.

[0012] The light receiving unit is provided with two image capturing devices,
These devices were configured so that images were alternately captured by the optical switching elements during the image capture time of each device. When the hologram element is used as the optical switching element, it is configured to modulate the wavelength of the laser.

[0013]

Embodiments of the present invention will be described below.

According to the present invention, an image processing system having two light receiving elements in a light receiving section is a main part. FIG. 1 shows an overall schematic diagram. FIG. 2 shows the light receiving section.

FIG. 1 is a schematic configuration diagram of a three-dimensional measuring device. An object to be measured is illuminated by a light source, and image data is captured by a light receiving unit. Image data captured by the light receiving unit is processed by an image processor via an A / D converter and an interface, and displayed on a display via a frame buffer.

FIG. 2 shows a light receiving section which is a main part of the present invention.
It will be described according to. First, the light receiving section is a light receiving element C
It has two CD devices 1 and 2. The image that has entered the lens system 3 is a CCD image when the shutter 4 is not lowered.
Create an image on device 1. Here, the optical path is changed by the shutter 4 and the mirror 5 by closing the shutter 4 having the mirror function in the CCD device 2 during the time when the CCD device 1 processes the optical information. At this time, the CCD device 2 captures an image. When the image capture of the CCD device 2 is completed, the shutter 4 is opened and the CCD device 1 is opened.
Make sure that the image is displayed on the screen.

As described above, the information processing time is reduced by utilizing the response time of the CCD device. Of course, the conversion times of the two CCD devices are synchronized by the CPU.

[0018]

In the above-mentioned case, the information processing time is shortened by using two CCD devices. However, in the present embodiment, the light receiving section does not use a shutter but uses a diffraction grating. It utilizes properties.

As the diffraction grating, a method of using a device such as ferroelectric liquid crystal or lithium niobate known as a spatial light modulating element, or a method of converting an optical path using a hologram element can be considered. When the shutter is used as described above, the durability time is inevitably shortened.
In addition, it is conceivable that the accuracy is reduced because the mechanically movable portion is inclined with respect to the optical axis. Therefore, a method of electrically changing the optical path without using a movable part is required. That is the present embodiment. The contents are shown in FIG.
The optical switching device 6 inserted in the optical axis of FIG. 3 is configured by using the above device.

Regarding the optical switch device, when an electric field is applied, the deflection surface rotates due to the Faraday effect. By using a deflector for the light that passes through the light modulation element and then passes through the prisms with different refractive indices for S and P waves, the light comes out at an angle only when an electric field is applied. . In this way, the light is distributed to the two CCD devices 7 and 8. When a hologram element is used, the same light switching can be performed by changing the wavelength of the laser light. However, when a hologram element is used, it is necessary to devise a configuration of the slit light emitting section. Since tunable lasers are being developed, hologram elements can be used sufficiently if this device is devised.

The CCD device has a synchronization of 5 when responding.
Since it is about 0 Hz, a frequency of about 100 Hz, which is twice as high, can be expected. This means that the image processing speed is improved at the same time, so that the object of the present invention is achieved.

[0022]

As described above, according to the present invention, the image processing speed can be increased. Also, by combining with a PSD element or the like, high-speed and high-resolution measurement can be performed.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram of a three-dimensional measuring apparatus according to the present invention.

FIG. 2 is an explanatory diagram of a light receiving unit.

FIG. 3 is an explanatory diagram of an embodiment utilizing the wavelength dependence of a hologram element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CCD device 2 CCD device 3 Lens 4 Shutter 5 Mirror 6 Optical switch element 7 CCD device 8 CCD device

Claims (3)

[Claims] In a three-dimensional measuring apparatus for receiving an image by a light receiving means via a lens and performing image processing, two CCDs for receiving light are used, and a mirror provided between the lens and each CCD is rotated. A three-dimensional measuring device configured to deflect the light so that the other CCD captures an image during the processing time of the other CCD. 2. A light receiving section comprising two image capturing devices,
A three-dimensional measuring apparatus characterized in that these devices are configured so that images are alternately captured by an optical switching element during the image capturing time of each device. 3. The three-dimensional measuring apparatus according to claim 2, wherein a hologram element is used as said optical switching element, and is configured to modulate a wavelength of a laser.