JPS59140432A - Light source device for reader printer - Google Patents

Abstract

PURPOSE:To obtain intensive illuminating light by a copying system without deteriorating film at the time of copying by placing a mirror for irradiating a reflected light to a condenser lens, in the vicinity of a linear lamp 10 of a light source, and vibrating it by a prescribed cycle. CONSTITUTION:In case of taking a copy, a mirror 20 is fixed as a full line, reflected light (full line part) LL is irradiated to only a part required for scanning on a film 3 through a condenser lens 2, and a slit exposure is executed. A picture of a desired frame of film becomes a copy by carrying a film 3. In case of projection to a screen, the mirror 20 is vibrated by a prescribed cycle centering around a shaft CL by driving a driving mechanism 21. As a result, a scanning part SC on the film 3 is moved completely, and an image is projected to the screen behind a projection lens 4. In this way, even when a light source lamp of the same light quantity is used, an intensive illuminating light is obtained, especially in a copying system, and one spot on the film is not irradiated for many hours, therefore, it is also possible to prevent the deterioration of film.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sixth structure of a light source device for a league printer.

In printers that project film (e.g. microfilm) images onto a screen or scan and expose them to make hard copies, the amount of light required for the copy system is much larger than that required for the screen system. Therefore, a large light source may be required. Figure 1 shows the optical system of such a league printer, in which luminance light L1 from a light source 1 is condensed by a condenser lens 2, and the film 3 is irradiated with the output light L2. . The light transmitted through the film 3 is input to the projection lens 4, and the light L3 from the projection lens 4 is separately switched and projected onto a screen or a photoreceptor. That is, when a film image is to be verified, the transmitted light of the film 3 is projected onto a screen placed in front of the projection lens 4, and when a hard copy of the film image is to be taken, , the transmitted light of the filter A 3 is projected onto a photoreceptor through a projection lens 4.

In this case, the intensity of the projection light may have to be made thicker when taking a bart copy than the intensity of the light when projecting the image of the film 3 onto the screen. However, if the amount of light emitted from the light source 1 is simply increased when making a hard copy, the film 3 will be exposed to radiant heat and ultraviolet rays from the light source 1 for a long time, leading to deterioration of the film 3. Therefore, the object of the present invention is to provide a light source device for printers that can provide strong illumination light in a copying system without deteriorating the film during copying.

This invention will be explained below.

As shown in FIG. 2, which corresponds to FIG.
is arranged so that the mirror 20 vibrates in a predetermined cycle. In addition, a linear lamp 10 and a mirror 2
The schematic structure of 0 is shown in FIG. 3, and the linear lamp 10 includes a long-shaped light emitting source 11 and a reflecting plate whose curved inner surface is mirror-finished, which is arranged along the back surface of the emitting source 11. 12, and a rectangular mirror 20 is disposed at a position where light from the light emitting source 11 and the reflecting plate 12 is irradiated. The mirror 20 is vibrated by a drive mechanism 21 such as a motor at a predetermined cycle (for example, 50 cycles) about the center line CL in the longitudinal direction of the mirror 20.

In such a configuration, when making a copy, the mirror 20 is fixed as shown by the solid line in FIG. Slit exposure is performed to irradiate only the area and make a hard copy. At this time, by transporting the film 3 by a desired amount according to the exposed portion, the screen of a desired frame of the film can be made into a copy.

When projecting the image of the film 3 onto a screen using electric power, the drive mechanism 21 is driven to vibrate the mirror 20 in a predetermined cycle around the axis CL. Thereby, the scanning unit SC on the film 3 can be moved entirely according to the vibration, and the image on the film 3 can be projected onto the screen disposed behind the projection lens 4.

This takes advantage of the fact that there is an afterimage in human vision, and projection unevenness can be prevented by increasing the vibration frequency of the mirror 20.

FIG. 4 shows how the image is projected on the screen, where NS shows the part not illuminated by the reflected light LL from the mirror 20, and SC shows the scanned part on the film 3 mentioned above. ing.

Here, if you want to obtain uniform irradiation light, mirror 2
When scanning with zero vibration, only the screen range (
When scanning A-B), the irradiation time near positions iA and B is longer than the irradiation time near the center C, so the irradiation is not uniform in terms of light quantity. Therefore, it is necessary to scan a range longer than area AB. Also, especially position A
By scanning only the range from to B, the peripheral area of the screen can be illuminated brighter than the central area.
This is an effective means for eliminating the so-called hot spot phenomenon in which the central portion of the screen appears bright.

In this way, by varying the scanning speed, it is possible to illuminate a part of the screen brighter than other parts.

As described above, according to the light source device of the present invention, extremely efficient illumination is possible, the power consumption of the light source can be reduced, and the capacity of the light source lamp can be reduced. Furthermore, even if a light source lamp with the same amount of light is used,
In addition to providing strong illumination light especially for copy systems, film I
- Since one point is not irradiated for a long time, deterioration of the film can also be prevented.

Claims (1)

[Claims] A light source device for a league printer in which light from a light source is irradiated onto a film L through a condenser lens, and transmitted light from the film is projected onto a screen system or a copy system through a projection lens, wherein the light source is a linear lamp. A light source device for a league printer, characterized in that a mirror for irradiating reflected light onto the condenser lens is disposed near the linear lamp, and the mirror can be vibrated in a predetermined cycle.