JPS61184529A - Copying device - Google Patents

Abstract

PURPOSE:To prevent the leakage of light from the platen glass face outside of an area occupied by an original face by adding a light reflecting plate that cuts off the irradiation of light of at least one side end of an exposure lamp to the direction of a platen glass and makes incident on a reflecting mirror. CONSTITUTION:For instance, an original 13 having relative thickness is placed at the specified position of the platen glass 14 and a movable light reflection plate 16 is slid according to the position of the original while conforming it with the original 13. The rays of light from solid white part other than the original is reflected by the photosensitive body. Accordingly, the leakage of light to the face not occupied by the original on the platen glass 4 does not occur. Thus, the leakage of light can be prevented only by adding the light reflecting plate, and the developing of solid black image can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to cases where the size of the original to be copied and the copy paper are different, and the original is smaller than the copy paper and the copying operation is performed in a trench where the light of the exposure lamp leaks. The present invention relates to a copying apparatus equipped with a light reflecting plate that prevents a portion corresponding to the difference between the original and the copy paper from being transferred as solid black onto the copy paper.

Conventional Technology In the past, when copying a tall document such as a book, the platen cover was not completely closed due to its height, or the platen cover was left open to avoid light leakage. Then, in order to prevent the solid black from being transferred to the area on the document table corresponding to the difference in size between the original and the copy paper due to the light leakage, place white paper etc. around the original to prevent the light leakage. As shown in Japanese Unexamined Patent Publication No. 58-158662, the document size position is detected and a blank exposure lamp provided around the photoreceptor is operated according to the size position to perform blank exposure and eliminate unnecessary Methods have been devised to prevent the occurrence of black spots.

Problems to be Solved by the Invention This invention solves the problem that it is impossible to install a new blank exposure light source and document size/position sensor in an ultra-compact copying machine because there is no extra space, and the cost is also high. had.

In view of the above-mentioned problems, the present invention provides a document stand that can accommodate all original sizes, requires almost no space, and can be easily mounted on a copying machine. In the exposure process of a copying machine, an image of the document surface is captured by light irradiated from below the entire surface of the document placed at a predetermined position on the platen glass, and is focused on a photoreceptor. In order to prevent light leakage from the surface, a movable document illumination optical system consisting of a light source and a reflection mirror is provided with a reflection mirror that blocks the emitted light from at least one end of the exposure lamp toward the platen glass. It is equipped with a configuration in which a light reflecting plate is added to allow the light to enter.

Effect of the present invention With the above-described configuration, light leakage can be prevented by simply changing the light reflecting plate, which has a light reflection performance that can accommodate all document sizes, in accordance with the document size, and as a result, solid black appears on the photoreceptor. Only the original will be copied.

EXAMPLE An embodiment of the present invention will be described below with reference to all the drawings. FIG. 1 shows a side view (front side) of an exposure section of a copying apparatus in an embodiment of the present invention. In Figure 1, 1
2 is an exposure lamp, 11 is a reflective mirror, 13 is an original, 14
15 is a platen glass, 15 is a document cover, and 16 is a movable light reflector. 0 The movable light reflector 16 is in the optical path between the exposure lamp 12 and the platen glass 14, and the photoconductor is located at one end of the exposure rung. It is arranged perpendicularly to the running direction of the drum (not shown in the drawings) and can be moved in the direction according to the document size.In addition, when the light reflector is not in use, it can be stored, for example, by a roll type. , bellows type, or folding type.

The operation of the exposure section of the copying apparatus configured as described above will be explained below.

Place a tall original 13 on a predetermined position on the platen glass 14. According to the original position, the movable light reflecting plate 16 slides completely in accordance with the original 13. The light reflecting plate 16 covers the flat white part other than the original part, and the reflected light is exposed to light. Since it is reflected by the body, there is no possibility of leakage onto the non-document-occupied surface of the platen glass.
(One driving portion of the light reflecting plate is omitted.) FIG. 2 is a complete side view (sheet feeding side) of the exposure section of the copying apparatus.

As described above, according to this embodiment, light leakage can be prevented simply by providing a light reflecting plate, and the appearance of a solid dot image can be prevented.

Next, other embodiments of the present invention will be described with reference to the drawings.

FIG. 3 shows a side view (sheet feeding side) of the exposure section of a copying apparatus in a second embodiment of the present invention.

In the figure, 12 is an exposure lamp, 11 is a mirror, 13 is an original, 14 is a platen glass, 15 is an original cover, 16
il-1t is a movable light reflector. The difference from the configuration shown in FIG. 2 is the position of the document 11 placed on the platen glass.

In this case, unlike the previous example, the original 11 is placed at the center, and the light reflecting plate is placed between the exposure lamp 12 and the platen glass 14 in a direction perpendicular to the traveling direction of the photoreceptor drum (not shown in the drawing). They are placed in the optical path at both ends of the exposure lamp, and are moved according to the document size to prevent light leakage.

Further, the operation and other aspects are the same as those of the first embodiment.

Note that in the above two embodiments, an aluminum plate having a mirror surface is used as the light reflecting plate.

Effects of the Invention As described above, according to the present invention, when copying a tall original such as a book, if the platen cover cannot be completely closed due to the height, the light leakage may cause a flat black to be placed on the original table. It is possible to easily and inexpensively prevent the image from being transferred to the area corresponding to the difference between the original size and the copy paper, resulting in a high-quality image fJ.
J', and can also be installed in a microcopying machine, which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a side view of an exposure section of a copying apparatus according to an embodiment of the present invention, FIG. 2 is a side view of an exposure section of a copying apparatus according to an embodiment of the present invention, and FIG. FIG. 3 is a side view of the exposure section of the copying apparatus in the embodiment. 11... Reflection mirror, 12... Exposure lamp, 13... Original, 14... Platen glass, 15... Original cover, 16・・・・・・
...Movable light reflector. Name of agent: Patent attorney Toshio Nakao and 1 other person/l
Warped mirror, /l-optical A4 fiber Fig. 2 Fig. 3

Claims (1)

[Claims] In the exposure process of a copying machine, an image of the document surface placed at a predetermined position on the platen glass of the document table is captured by light irradiated from below and formed on a photoreceptor.
In order to prevent light leakage from the platen glass surface that is not occupied by the document surface, a fixed or movable document irradiation optical system consisting of a light source and a reflecting mirror is provided with a platen glass that emits light from at least one end of the light source lamp. A copying apparatus characterized in that a light reflecting plate is added for blocking radiation in a direction and making it incident on an opposite mirror.