RU41860U1 - DEVICE OF THE OPTICAL NODE OF REGISTRATION OF IMAGE FOR CONTROL OF FOCUSING OF A LASER BEAM IN PHOTO-OUTLET AUTOMATIC MACHINES - Google Patents

Abstract

The proposed utility model relates to devices for measuring the small linear dimensions of a laser recording point and can be used in printing at the prepress stage when outputting photoforms (FF) on high-resolution photo output devices - photographic typesetters (FNA). The technical result of the proposed solution is to eliminate the disadvantages presented: providing a larger increase in combination with expanding the range of possible sizes of the studied laser point due to the use of a replaceable input lens in a microscope, as well as improving the accuracy of image transmission through the use of a microscope with a spatial filter and installation as an image receiver television camera, and simplifying the design of the device by placing elements of an optical system we are on the same axis. This object is achieved in that the device of the optical image recording unit for monitoring the focus of the laser beam in the output devices contains a microscope, which consists of an input lens and an eyepiece, and an image receiver, while the input microscope lens is configured to replace lenses and in the rear focal plane contains an aperture diaphragm with a spatial filter, and the eyepiece is placed so that in its front focal plane the input lens builds an image, while the image receiver eniya formed as a TV camera attached to the microscope eyepiece portion. All optical elements are located on one axis.

Description

The proposed utility model relates to devices for measuring the small linear dimensions of a laser recording point and can be used in printing at the prepress stage when outputting photoforms (FF) on high-resolution photo output devices - photographic typesetters (FNA).

Known control unit focusing the laser beam on the film in a photo-recording device for reproducing low-contrast images. Published: V.D.Smirnov. "Optics, optoelectronics and laser technology in printing", St. Petersburg, publishing house "Petersburg Press Institute", 2000, p. 312. It consists of a microscope and an image receiver.

The microscope has an input lens, divided into two parts by a fiber optic bundle: the first has a single magnification, the second is fixed five times. A mirror is located in front of the first lens and changes the path of the rays by 90 ° to get them into the optical system. The second lens builds an image of the laser point on the image receiver - the photosensitive surface of the charge-coupled device (CCD). A translucent mirror is placed between these elements, giving an auxiliary beam of rays perpendicular to the optical axis of the entire system. It enters the eyepiece and allows you to observe an enlarged image of the recording point visually. However, the main thing is to display it on a TV screen, where the video signal from the output of the CCD is supplied.

The main disadvantages of the device are the low quality of the final image, which serves to assess the possible defocusing of the laser beam, as well as a narrow range of sizes of the recording point to be analyzed. First

due to the manifestation of the network structure of the fiber optic bundle in the image and a small increase (5 times) of the microscope objective. The fixed value of this increase determines the second drawback. In addition, this optical unit has a rather complex structure.

The technical result of the proposed solution is to eliminate the disadvantages presented: providing a larger increase in combination with expanding the range of possible sizes of the studied laser point due to the use of a replaceable input lens in a microscope, as well as improving the accuracy of image transmission through the use of a microscope with a spatial filter and installation as an image receiver television camera, and simplifying the design of the device by placing elements of an optical system we are on the same axis, - that in combination allows to effectively treat the computer digital image recording imagesetter point obtained with CCDs.

This object is achieved in that the device of the optical image recording unit for monitoring the focus of the laser beam in the output devices contains a microscope, which consists of an input lens and an eyepiece, and an image receiver, while the input microscope lens is configured to replace lenses and in the rear focal plane contains an aperture diaphragm with a spatial filter, and the eyepiece is placed so that in its front focal plane the input lens builds an image, while the image receiver eniya formed as a TV camera attached to the microscope eyepiece portion. All optical elements are located on the same axis.

The device diagram of the optical image recording unit is shown in FIG. The numbers denote: 1 - a microscope, 2 - an image receiver (television camera), 3 - an input lens, 4 - an aperture diaphragm with a spatial filter, 5 - an eyepiece.

In the tube of the microscope 1, on the same optical axis, there is an input interchangeable lens 3, an aperture diaphragm with a filter 4 spatially aligned with the object, located in the rear focal plane of the lens 3, and an eyepiece 5, in the front focus of which the lens builds an image. On the ocular part of the microscope, an image receiver is fixed — a television camera 2 with an array photodetector at a CCD.

The principle of operation of the device: microscope 1, in the focus of which should be placed the film of the recorded FF, gives an enlarged imaginary image of the object of study - the laser point on it. In this case, the spatial filter in the plane of the aperture diaphragm 4 does not pass the low frequencies of the image signal of the point, thereby increasing its sharpness. Image registration on a matrix photodetector takes place in a television camera 2, the microcircuit of which generates a video signal that carries information about the image under study. Further, this signal is used for computer processing.

The arrangement of optical elements described above makes it possible to obtain a video signal with a high-quality digital image of a laser dot at the output. It is significant that the design was significantly simplified in comparison with the prototype. The ability to change the lenses in the input lens allows you to control the magnification of the microscope and achieve its maximum possible value. The registration of the image of the laser point with a large magnification by a television camera having a matrix photodetector provides geometric and gradation accuracy of the output signal with respect to the input signal and makes it possible to further perform a computer analysis of its characteristics.

Claims (1)

A device for an optical image recording unit for monitoring the focus of a laser beam in photo output devices, comprising a microscope that consists of an input lens and an eyepiece, and an image receiver, characterized in that the input microscope lens is configured to replace lenses and contains an aperture diaphragm in the rear focal plane with spatial filter, and the eyepiece is placed so that in its front focal plane the input lens builds an image, while the image receiver is made in the form of a body a vision camera mounted on the ocular part of the microscope, all optical elements being located on the same axis.