SU653986A1 - Photoelectric device for linear scanning of images - Google Patents

Description

The invention relates to a measurement technique and can be used for non-contact measurement and control of linear dimensions and position of objects.

Devices for scanning shadow images of objects are known, comprising a light source, a projection system, a light-transmitting diffusing screen, photodetectors, and a scanning node 1.

These devices with sufficient performance do not provide high accuracy of measurement without significantly complicating their design. The closest to the proposed invention in terms of its technical essence and the effect achieved is a photoelectric linear image scanning device comprising a light source, a projection system, a light transmitting scattering screen, a rotating scanning element,. coupled to an electric drive and a photodetector optically coupled to the screen via scanning; element. In addition to the rotational scanning element (polyhedral mirror), the scan node in such a device

contains a light source and a device for deforming the holder and. mirror deflection 2.

However, such a device has insufficient measurement accuracy and speed due to the need to keep the collimated beam strictly at a certain point during the scanning process.

0

The purpose of the invention is to improve the measurement accuracy and speed of the device.

This is achieved by the fact that the screen in the device is made of adjacent

5 parallel optical fibers with a transparent input end, perpendicular fibers, and a matte output end made in the form of a concave cylindrical surface (the guide of which has a linear relationship between the polar angle and the abscissa).

The drawing schematically shows one of the embodiments of the proposed device.

The device contains a source of svega 1, a projection system 2 and located inside the opaque: the orpus 3, light transmitting scatter

A rotating screen is a light guide 4 rotating a scanning disk 5 with radial holes 6, connected to the actuator 7, and a photodetector 8. The rotational axis of the scanning disk 5 is aligned with the axis of the application of the spreader output end 9 of screen 4, while the photodetector 8 is mounted on the axis of rotation of the disk five.

The device works as follows.

The shadow image of the object to be monitored 10 is projected onto the transparent end face 11 of screen 4. Next, the light that falls on screen 4, diffused on the output end 9 of screen 4, forms an image of a part of object 10, the boundaries 12 of which correspond to the contour of the image of object 10 at the input end 11 screens 4,,

The passage through the holes 6 of the disk 5, rotated by the actuator 7, the radiation falls on the photodetector 8 and then on the electronic measuring unit (not shown).

With an even movement of the object 10 across the narrow entrance end 11 of the screen 4, the entire image is scanned line by line.

The linearity of the device is provided by the proposed execution of the end 9 along a guide having a linear relationship between the polar angle and the abscissa.

(,

Where

, 4 - respectively the abscissa, ordinate, and polar angle of the guide

To - the coordinate of the maximum

equals.

At a constant linear increase in f of the projection system 2 and a constant angular velocity from the scanning disk 5, the time interval t corresponding to the desired size L will be equal to:

 .g.

t

K sh

Claims (2)

1. USSR author's certificate No. 254792, cl. D 01 H 13/32, 1969, 2. US patent number 3657792, class, G 01 11/25, 1972. YU P