SU758047A1 - Light optical system for motion-picture film printing apparatus of continuous additive printing - Google Patents

Description

The invention relates to kinotehnika and can be used in the apparatus of additive printing, in which to create spectrozonal flows are used as absorption, hook and interference light filters.

Light-optical systems for continuous additive printing machines are known, in which an increase in the output aperture angle is achieved by using cylindrical lenses in a condenser [H |.

Closest to the invention is an optical-optical system for continuous additive printing machines with a spiral filament lamp, the turns of which are oriented perpendicular to the printing direction, additive light filters and a regulator, exposures installed between the condenser and the collective lens, the light guide from two inclined mirrors oriented perpendicular to planes

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passing through the optical axis in the direction of printing, and the printed window £ 2].

However, in this optical-optical system, the increase in the output aperture angle is limited due to the loss of light in the light guide. Light losses in the light conductor increase with an increase in the input aperture angle, the angle between the inclined edges of the light guide, and the length of the light guide. In addition, the light loss depends on the shape of the surface of the light guide facing the exposure regulator. The angle between the inclined edges of the light guide and its length cannot be selected less than certain values, since og the design parameters of the print unit: the width of the image of the lamp filament, the width of the printed window, the distance from the exposure control to the printed window. The input aperture angle can be reduced if the light guide is installed in parallel with the rays.

The aim of the invention is to increase the illumination and simplify the design

758047

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whilst maintaining satisfactory light-color control conditions.

This is achieved by the fact that the focal plane of the condenser is aligned with the lamp filament, and the focal plane of the collective lens with the printed window in the cross section perpendicular to the printing direction and with the plane passing through the top of the angle formed by the light guide mirrors, in the section coinciding with the printing direction .

Fig. 1 shows the optical scheme of the device described, which uses additive absorption filters for the spectrozone division; in fig. .2-4 shows options for hone rays through a collective lens and a light guide at different focal lengths of a collective lens; in fig. 5 shows the optical scheme of the device, in which additive interference light filters are used for the spectral division.

The thread of the lamp 1 is depicted with the help of the condenser 2 and the spherical cylindrical collective lens 3 in the printed window 4 in cross section perpendicular to the direction of printing. The focal planes of the condenser 2 and the collective lens 3 in this section are combined with the corresponding thread of the lamp 1 and the printed window 4. In a parallel path of rays between the condenser 2 and the collective lens 3, additive filters 5 are installed, the shape filter 6 and the passport 7, acting as an exposure regulator . In the section coinciding with the direction of printing, light is directed from the collective lens S, the printed window 4 through the light guide / consisting of two mirrors 8, equally inclined to the optical axis. In this section, the focal plane of the collective lens 3 is aligned with the plane passing through the vertex A of the angle formed by the light guide mirrors 8. For the sake of simplicity, the diagram does not show the reflector used for increasing the illumination and the heat filter.

This device uses a lamp 1 with a spiral thread, the turns of which are oriented perpendicular to the direction of printing. The thread of the lamp 1 in the section perpendicular to the printing direction is displayed directly in the printing window 4. In this case, a satisfactory uniformity of illumination of the printed Window 4 can be ensured, since the brightness distribution along the turns of the lamp 1 is uniform.

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In the section coinciding with the direction of printing, the thread of the lamp 1 is not shown in. printed window 4, as this reduces the accuracy of the level measurement and especially the uniformity of illumination due to the fact that the dimensions of the light receiver (not shown) of the film copy photometer (not shown) are comparable with the sizes of the displayed turns of the lamp 1 filament. control in this section provides continuous illumination of the printed window 4 with the help of mirrors 8 light guide.

Due to the fact that the collective lens 3 is installed in a parallel course of rays, and its focal plane in section, coinciding with the printing direction, is aligned with the plane passing through the vertex A of the angle formed by the light guide mirrors 8, the light loss in the light guide can be significantly reduced the illumination of the printing window 4. Under the above condition, the focal length of the collective lens 3 (1 ' _k ) is approximately''. .

G ^and k '·. ··

where a _to - the light size of the lens 3 in this section;

on - half the angle formed by the light guide mirrors 8. FIG. 2-4 schematically show variants of the path of the rays through a collective lens 3 and

Ί · - ι ^a *

the light guide when 1D = "3 (Fig. 2), 1 _to (Fig. 3) and ₌ (Fig. 4).

Under the accepted condition (Fig. 3), the rays exit from the light guide at lower aperture angles. Owing to this, the loss of light by multiple reflection is reduced, and a smaller part of the light-. go beam passes the printed window. Light loss is also reduced with a decrease in the scattering angle of a parallel light beam. In this device, this angle can be made smaller than the entrance aperture angle in existing devices with non-parallel ray propagation through the exposure control.

Similar light-optical system

can be performed using

additive interference light filters (Fig. 5). In a parallel course

5. 7 58С

rays between the condenser 2 and the collective lens 3 are installed additive interference light filters 5, which carry out spectroionic division.

In the three additive zones are set ₅

light valves 9 that perform the simultaneous functions of a forfilter and an exposure passport. The spiral filament lamp 1 and the light guide mirrors 8 are oriented with respect to the direction of the chatter in the same way as in the device shown in FIG. one.

This device has a simple construction and smaller size, since it does not use lenses izob- ₅ reflects in the lamp filament exposure control plane, and the exposure controller can be set closer to the condenser.

The principle of operation of the device will not change if the collective lens is replaced with several lenses, and the light guide is shortened. In this case, the condition relating to the alignment of the focal planes of the system of collective lenses, respectively, with the printed window and the apex of the angle formed by the light guide mirrors, should be observed.

Claims (1)

Claim Light-optical system for continuous copying machine 4/6 printing, containing a spiral filament lamp, the coils of which are oriented perpendicular to the print direction, additive filters and an exposure control mounted between the condenser and the collective lens, the light guide from two inclined mirrors oriented perpendicular to the plane passing through the optical axis in the print direction, and a printed window, which differs from that in order to increase the illumination and simplify the design while maintaining satisfactory light-color control conditions, the focal area bone condenser is combined with a filament lamp, a collective lens focal plane - with a printed window in a section perpendicular to the printing direction, and a plane - passing through the vertex of the angle formed by the mirrors in the lightguide, in cross section coinciding with the printing direction.