JPS60179728A - Lighting device of copying machine - Google Patents

Abstract

PURPOSE:To irradiate uniformly the entire lighting area of an original platen and to make the quantity of the irradiating lights uniform, by providing parabolic reflecting mirrors which reflect part of lights of flash lamps to the upper part of reflecting shades at the original platen below the flash lamps. CONSTITUTION:Stepped section 21 are respectively formed at both side walls 10c and 10c of the box body 10 of a bottom reflector 11 and parabolic reflecting mirrors 22 are installed to the stepped section 21. The parabolic reflecting mirrors 22 are constituted in such a way that flash lamps 17 are their focal points and axes B and B' are parts of their parabolas toward both end parts of an original platen 15, and they are provided so that lights of the flash lamp 17 can be reflected to the upper part A, and A' of reflecting shades 18 of the original 17 are reflected by the parabolic reflecting mirrors 22 to the upper pat A and A' of reflecting shapes 18 of the table 15, the entire lighting area of the original platen 15 can be irradiated evenly with uniform light quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an illumination device for a flash exposure type copying machine.

BACKGROUND ART FIG. 1 is a schematic explanatory diagram of a flash exposure type copying machine, and above a belt-shaped photoreceptor 1 is an illumination device. A charger 3.2 is provided around the photoreceptor 1. A developing device 4, a transfer device 5, and a cleaning device 6 are arranged in this order, and the paper 8 in the tray 7 is conveyed toward the transfer device 5 by a paper feed roll 9.

The lighting device 2 has an inner surface 10 of a box 10 that is open at the top.
Lower reflector 1 with diffusive white highly reflective paint applied to α
1 and an upper reflector I3 whose inner surface 12α of a box body 12 with an open bottom is coated with diffusive white high-reflection paint gold. A 15-karat gold original plate is provided on the upper wall 12/j, and a lower reflector 11 is provided.
0 box body] Below 0! 10b is provided with a lens 16, and both side walls 100. IOC has a flash lamp 17.1
7 and a reflective shade 18.18 coated with a diffusive white reflective paint.

The light from the flash lamps 17.17 is diffused and multiple reflected inside the lower and upper reflectors I+ and +3 to illuminate the entire surface of the document 19 on the document table 15, and the reflected light is reflected by the lens 16 and the CO84 power law. The photoreceptor 1 is illuminated through the corrector 20.

Such a lighting device has the advantage that it functions like a kind of integrating sphere and has high lighting efficiency.

However, on the other hand, since the reflective shade 18 is provided to prevent the light from the flash 2 lamp 17 from directly illuminating the original platen 15, the upper part of the reflective shade 18 in the illumination area of the original platen 15, that is, A.

The A' portion is in the shadow of the reflective shade 18, and the amount of light is smaller than other portions as shown in FIG. 2, which has the disadvantage of adversely affecting the quality of the copied image.

OBJECTS OF THE INVENTION It is an object of the invention to uniformly illuminate the entire illumination area of a document table to make the amount of light uniform.

Structure of the Invention A parabolic reflector is provided below the flash lamp to reflect a part of the light from the flash lamp onto the upper part of the reflector on the document table.

Embodiment FIG. 3 is a sectional view of the illumination device, in which the lower reflector 11
Since the lighting device is the same as the conventional lighting device shown in No. 1- with only a part of the difference, the explanation will be omitted by using the same reference numerals.

Both side walls 10C9lQC of the box body 10 of the lower reflector 11
A step portion 21 is formed in each of the step portions 21, and a parabolic reflecting mirror 22 is disposed in the step portion 21.

The parabolic reflection @22 is focused on the flash lamp 17 and the axis B
, B' has the shape of a part of a parabola facing both ends of the document placement table 15, and the light from the flash rung I7 is arranged so as to be reflected to the upper part of the reflective shade 18 of the document placement table 15, N. It is.

Because of this, a part of the flash lamp 17° 170 light is reflected by the parabolic reflector 22, 22, and the reflection shade +8. Since the light is reflected by the upper portions A and A' of I8, the light is uniformly illuminated over the entire illumination area of the document table 15, resulting in a uniform light amount distribution over the entire illumination area as shown in FIG. Become.

Therefore, there is no negative effect on the quality of the copied image.

In addition, in one or more embodiments, two flash lamps were used, but one side wall loC, lot? The same applies when a pair of flash lamps is also provided on the side wall orthogonal to the side wall.

Effects of the Invention Since the light from the flash rung 17 can be uniformly illuminated over the entire illumination area of the document table 15, a uniform light amount distribution can be achieved over the entire illumination area.

Therefore, it is possible to provide uniform illumination over the entire illumination area while maintaining the advantage of high illumination efficiency, making it possible to obtain a copy image of high quality.

[Brief explanation of drawings]

The first factor is a schematic explanatory diagram of a copying machine using the flash exposure method.
1 is a sectional view of an illumination device showing an embodiment of the present invention, and FIG. 4 is a front view showing the light amount distribution by the illumination device. 14 is a reflector, 15 is an original table, 17 is a flash lamp, 18 is a reflector, and 22 is a parabolic reflector. Applicant Fuji Xerox Co., Ltd. Agent Patent attorney Tadashi Yonehara Military patent attorney Tadashi Hamamoto Figure 2 Figure 4 (Illumination position tf2 of manuscript loading table)

Claims (1)

[Claims] 7 lash lamps 17 are provided on the side wall of the straight reflector whose inner surface is coated with a diffusive white highly reflective paint, and a reflective shade 18 is provided above the flash lamp 17. The entire mounting table 15 is provided, and a parabolic reflector 22 is provided below the flash rung 17 to reflect a part of the light from the seven flash rung f7 onto the upper part of the reflector 1g on the manuscript table 15. Copying machine lighting system as a percentage mark.