SU1213504A1 - Device for photographic marking of linear scales - Google Patents

Description

The invention relates to instrument making, namely, devices for the manufacture of scales, diffraction gratings, code elements.

The purpose of the invention is to improve the accuracy of marking the scales with any step size.

The drawing shows a diagram of a device for photomarking linear scales.

The device contains a flat wavefront coherent light source 1, which specifies the optical axis of the device, the platform 2 moving along the optical axis with the holder 3 for the workpiece with the photosensitive layer, the reflector 4 mounted on the platform 2, 5-7 on the optical axis, the reflector 8 and the photodetector 9 located along the rays separated by the light carrier 7, the control unit 10, which is a frequency divider of a periodic signal (for example, IKE-15) electrically connected to the photo-output Receiver 9, two electro optical shutters 11, electrically connected to the output of control unit 10, located along separated by beam splitters 5 and 6 rays converging on the surface of the holder, reflector 12 located perpendicular to beam reflected by reflector 4, and reflector 4 is attached under a certain angle T, and the reflector 12 - at an angle of 2 IP to the optical axis of the device.

The angle is defined as follows:

I., -.

)/- (one)

where D is the wavelength of the source light;

 - the period of the marked scale AND is an integer. The function of the control unit eliminates the frequency divider of the periodic signal. The division factor corresponds to the value of N, while

,

where n is an integer corresponding to the expression (. I),

213504

m is an integer, a measure of the overlap t of the exposed sections of the scale. The operation is as follows.

5 way.

The light source 1 receives a beam of light through the beam splitters 5, 6 and 7 to the reflector 4 at a certain angle of incidence Y and to the reflector 12 at a zero angle of incidence. The main beam splitters 5 and 6 direct the separated light beams through the electro-optical shutters 11 to the area where the scale marks start,

15 to form a raster (local scale) on a photosensitive one; layer. A two-beam interferometer, formed by the beam splitter 7 and reflectors 4 and 8, via photodiode 9 gives to control unit 10 information about the phase difference of the rays forming the raster. Marking is performed by exposing the photosensitive layer when the plate 25 of Form 2 is shifted by one (or several). marking scale period (raster step}; When platform 2 moves, exposure is performed automatically, as the control unit 10 controls, by short pulses, opens electro-optical gates-11 at times when the platform 2 shift (measured by the interferometer on the phase difference) is exactly a multiple of

35 period marking scale.

Claims (1)

Invention Formula Photo marking device 40 linear slksh containing a source of coherent light, a platform movable along the optical axis with a holder for the workpiece with a photosensitive layer, beam reflectors, beam splitters located on the optical axis, a control unit, a photodetector, electro-optical gates, one reflector mounted on the platform, 50 another reflector and one of the beam splitters form a two-beam interferometer, the optical output of which is connected to the input of the photodetector, and the output of the photodetector J5 through the control unit is electrically connected to the electro-optical valves, located along the path of the separated beam splitters. J1213504. converging on the surface with an additional reflector, a rasteel, which is characterized perpendicular to the beam, from that, with the aim of directing it to the exact fixed on the platform scale markings with any reflector value that is located step size, it is provided5 at an angle to the optical axis.