JPS62238547A - Illuminating device for copying machine - Google Patents

Abstract

PURPOSE:To illuminate an original by a sufficient light quantity, and to prevent a black band part and a gray part from being generated on a part of a copy image, by forming a white painting part, and providing an auxiliary illuminating means except a slit exposure illuminating means for illuminating this painting part. CONSTITUTION:An original 5 which has been placed on an original platen glass 1 is illuminated by a slit exposure illuminating means. In a part corresponding to the tip of the original 5 on the surface of the original platen glass 1, a white painting part 6 to which a white paint has been applied is formed, and this device is constituted so as to provide an auxiliary illuminating means 7 except the slit exposure illuminating means for illuminating this white painting part 6. In this regard, an original illuminating light source lamp 14 provided with a reflector 13 being the slit exposure illuminating means, and a reflecting plate 15 for reflecting an irradiation light from this lamp 14 and illuminating the original 15 from the opposite side are provided. That is to say, by forming the white painting part 6 on the surface of the original platen glass 1, generation of a shadow is prevented and also, the white painting part 6 is illuminated by the auxiliary illuminating means 7 except the slit exposure illuminating means, and a drop of a reflected light quantity due to providing the white painting part 6 on the surface of the original platen glass 1.

Description

[Detailed description of the invention] (Industrial field of application)
This invention relates to an illumination device for a copying machine that exposes a margin to L'n16 sides 1 small I^-1 arms (2).

(Prior Art) Conventionally, there is a lighting device of this type as shown in FIG. In this case, the document 33 is placed on the document table glass 31 supported by the support frame 32 with its leading edge abutting against the abutment surface 34 of the support frame 32 . - H Note A white portion 35 made of white paint, white paper, or the like is formed on the back surface of the document table glass 31 so as to extend along the leading edge of the document 33. Therefore, when the document 33 is illuminated from two directions by the light source 37 with the reflector 36 and the auxiliary reflector 38 to prevent the occurrence of shadows on the bonded document, when slit exposure is performed, the leading edge of one image is exposed to light from the white FfB 35. A margin is exposed by reflected light to form a leading margin at the leading edge of the copy to prevent the copy paper from being wrapped around the fixing roller of the fixing device.

(Problem to be Solved by the Invention) However, in the case of such a conventional technique, when illuminating the leading edge of the original 33, the illumination light from the auxiliary reflector 38 is blocked by the white part 35 and the original 33 is When a shadow A appears above and the illumination light from the auxiliary reflector 38 is strong, i%A becomes dark and a black band appears on the copy. Therefore, in order to prevent this, it is necessary to reduce the intensity of the illumination IN+ light from the auxiliary reflector 38, which poses a problem in that the illumination efficiency cannot be improved.

Therefore, it is conceivable to provide the white part on the surface of the document glass, but in this case, the white part will not be shaded by the white part and the copy will not have a black band, but the white part can be placed on a material such as white paper. If the white member is formed by adhering it to the surface of the original glass, there arises a problem that the white member is likely to peel off because the original comes into contact with it.

Therefore, it has been proposed to form a white portion by applying white paint to the surface of the document table glass.

However, in this case, since the white paint is applied to the surface of the document platen glass, the aperture 11 number NA for exposure imaging in the white paint is the aperture I! of the document on the document platen glass I-! Number NA
, and the amount of reflected light 11+L from the white paint decreases. Therefore, a new problem has arisen in that as the development density is increased, the portion of the copy image corresponding to the portion coated with white paint becomes dark gray.

Therefore, the present invention has been made to solve the above-mentioned problems in the prior art. Is there black 4j on the corresponding copy image part? .

An object of the present invention is to provide a lighting device for a copying machine that does not cause dark or gray areas.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an illumination device for a copying machine that illuminates a manuscript placed on a document platen glass-H by a slit exposure illumination means. In.

A white painted part coated with white paint is formed on a portion of the document table glass surface corresponding to the leading edge of the document, and an auxiliary illumination means other than the slit exposure illumination means is provided for illuminating the white painted part. There is.

(Function) In the present invention, a white painted portion is formed on the surface of the document table glass to prevent the occurrence of shadows, and the white painted portion is illuminated by an auxiliary illumination means other than the slit exposure illumination means. This also prevents a reduction in the amount of reflected light due to the provision of the white coating on the surface of the document table glass.

(Example) The present invention will be explained below based on illustrated embodiments.

FIG. 1 is a longitudinal LE tl'Ii diagram showing one embodiment of the lighting device for a copying machine according to the present invention. In the figure, l denotes a document glass plate, and the periphery of the document glass plate l is supported by a support frame 2 and a support plate 3.

The end surface of the document table glass iH of the L support frame 2 is the document abutment surface 4.
is formed.

On the part of the surface of the document platen glass 1 corresponding to the leading edge of the document, white paint such as white paint is applied from the corner of the support frame 2 to the document surface 4 by a predetermined width toward the document 5 side in the L step of the shade ( The coating is applied thinly (approximately 10 to 200 lumens) in the form of a white coating 6.

In addition, the end surface of the document table glass l is formed into a downward prism shape, and the end surface 1a of the document table glass l has the following shapes.
Auxiliary illumination means other than the slit exposure illumination means described later are arranged. As shown in FIG. 2, this auxiliary illumination means includes an auxiliary illumination light guide plate 7 of Lc scale, and a light source 8 made of a halogen lamp or a tungsten lamp shade.
The light source 8 is disposed at one end of the auxiliary illumination light guide plate 7 in the longitudinal direction f. The auxiliary illumination light guide plate 7 is made of acrylic or the like, and by allowing light to enter from an end surface 9 at one end in the longitudinal direction, it irradiates light uniformly from one side surface 10 along the longitudinal direction (the bottom surface in the illustrated example). It has the function of That is, the auxiliary illumination 1j3 light guide plate 7 extends from the first surface 11 to the bottom surface 1.
41 of the JB+i refractive index whose refractive index gradually increases toward 0 is fixed by 1, and the light incident from the end face 9 at one end in the 7X-r direction is +r of the folded book; I:+i MF to chisel side (frh艷-doi?i 10)
-*- It looks like this. A reflecting plate is attached to the north face 11 side and the end face 12 side opposite to the light source 8 of this auxiliary lighting light guide plate 7, and the lower surface 10 thereof is a diffusion-treated surface to uniformly irradiate light. .

- As the above-mentioned auxiliary lighting means, a diffuser rod made of ordinary acrylic or the like may be used as long as it satisfies the uniformity of light 1 and the longitudinal direction, or a bar-shaped fluorescent rod if cost and size are satisfied. A light or the like may also be used.

Incidentally, below the document platen glass l, there is a light source lamp 14 for document illumination equipped with a reflective shade 13 as a stage f of slit exposure illumination, and a light source lamp 14 for illuminating the document is provided to reflect the irradiated light from the light source lamp 14 to illuminate the document 5. A reflecting plate 15 is provided that illuminates from the opposite side to the lamp 14, and by illuminating the cCC 50 from opposite directions, it is possible to prevent the occurrence of shadows when the original 5 has a bonded portion. The light reflected from the original 5 is exposed onto the photosensitive drum 19 via the mirrors 16 and 17 and the lens 18.

The photosensitive drum 19 rotates in the direction of the arrow, and is first uniformly covered by the heavy equipment 20, and then the image of the white coating part 6 and then the original 5 is formed by the slit exposure and illumination stage. It is projected to form a latent image. This latent image is developed by the developing device 21, and the portion onto which the reflected light from the white painted portion 6 is projected becomes a leading edge margin area to which toner does not substantially adhere. The transfer material 22 is transferred to a pair of registration rollers 23
The paper is conveyed so that its leading edge coincides with the margin and sent to the transfer section. In the transfer section, a transfer charger 24
The toner image formed on the drum 19 is transferred onto the transfer material 22, and after the transfer, the transfer material 22 is sent to a pair of fixing rollers 25 where the toner image is fixed. On the other hand, the drum surface after the transfer is cleaned by a cleaning member 26. Note that the document may be scanned by fixing the document table glass and moving the light source lamp and mirror shade.

In the above configuration, the illumination device of the copying machine according to this embodiment illuminates the original in a primary manner. That is, the original h45 is placed on the original platen glass l, and the leading end of the original 5 is brought into contact with the abutment surface 4 of the support frame 2. In this state, the light source lamp 14 is turned on, and the original 5 is illuminated by the light emitted from the light source lamp 14, either directly or via the reflective shade 13 and the reflective plate 15. At this time, since the white coating part 6 is coated on the surface of the document platen glass l, the numerical aperture NA for exposure and imaging in the white coating part 6 is larger than the numerical aperture NA of the original 5 on the document platen glass l'-. Smaller, white painted part 6
The amount of light reflected from the However, the L warm white coating section 6 is uniformly coated by the light emitted from the light sound (8) and irradiated from the side surface 10 (shown in the figure) of the auxiliary illumination light guide plate 7 that is in close contact with the end surface 1a of the document table glass l. Therefore, the light reflected from the white painted portion 6 has sufficient light, r,:.

is on the right, and in position 1 corresponding to the leading edge of the document on the photosensitive drum 19, b; be done.

By doing this, there is no shadow on the leading edge of the document unlike in the past, so the balance of the light irradiated by the light source lamp 14, the reflector shade 13, and the reflector plate 15 can be set freely, and the reflector The size and shape of the 15 can be freely set to improve illumination efficiency, and the light emitted from the light source lamp 14, the reflector 13, and the reflector 15 can be balanced to eliminate shadows from pasted originals. It can be done easily.

(Effects of the Invention) The present invention has the above-described structure and operation, and allows the document to be illuminated with sufficient light! , 1 can be illuminated, and there is a black mark on the part of the copy image corresponding to the leading edge of the original. It is possible to prevent the appearance of gray areas and gray areas.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of the illumination device for a copying machine related to unreleased light 11, and FIG. 2 is a perspective view showing one stage of auxiliary lighting r.
FIG. 3 is a vertical cross-sectional view of a conventional lighting device for a copying machine. Explanation of the sign -)

Claims (2)

[Claims] (1) In an illumination device for a copying machine that illuminates a document placed on a document table glass using a slit exposure illumination means, a white painted portion where white paint is applied to a portion of the surface of the document table glass corresponding to the leading edge of the document. 1. An illumination device for a copying machine, comprising auxiliary illumination means other than the slit exposure illumination means for illuminating the white painted portion. (2) A copy according to claim 1, wherein the auxiliary illumination means is made of a transparent light guide whose refractive index is distributed so that light incident from one end is uniformly irradiated over a wide area. Machine lighting system.