JPS5885459A - Electrophotographic copying device - Google Patents

Abstract

PURPOSE:To prevent the stain in the peripheral part of a copied paper, by providing a shielding plate between a platen glass plate and a light souce for exposure to cover the part where an original is not placed and preventing the leakage of light from the outside part of the original to reflect the light, which is incident to this part, to the inside. CONSTITUTION:An original 3 to be copied is placed on a transparent platen glass plate 2. A switch 6 for moving a flexible shielding plate 4 is depressed to rotate normally a motor 12 and a gear 13 connected to the motor 12, and the tip of the shielding plate 4 to which a rack 14 biting the gear 13 is attached is moved left along a guide 11, and the switch 6 is released at the end of the original 3. The motor 12 is reversed by a switch 7 to move the end part of the shielding plate 4 to the right. A shielding plate 5 is moved to the other end of the original 3 by the operation of switches 8 and 9 to complete preparation; and by depression of a switch 10 for exposure, a light source lamp 15 is lit to copy the original successively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic copying apparatus, and is particularly effective when copying thick materials such as books and magazines.

Usually, an electrophotographic copying device is equipped with a flat transparent glass plate called a platen that supports the original, but the size of the original to be copied is usually smaller than the size of the original platen glass. Light from the exposure light source leaks from around the document. This may hurt the eyes of the operator.

This may cause the periphery of the copied paper to become black. For this reason, the above two problems are usually solved by providing a white plate-shaped body called a document table cover that can be opened and closed, and covering the document from above during the copying operation. However, this opening/closing operation is not only extremely cumbersome as it is necessary each time the document is replaced, but it is also necessary to completely close the document table cover as described in -1- in the case of thick documents such as books and magazines. Since it is impossible to close, it has been difficult to fully achieve its purpose.

The present invention provides an electrophotographic copying apparatus having the functions described in JZ.

The gist of this is to provide a member (hereinafter referred to as a shielding plate) that extends from the inside of the portion of the document table glass that is not occupied by the document between the transparent document table glass plate and the exposure light source. This shielding plate prevents original leakage from the area where there is no document, and also reflects the light that hits that area inward.
This is to prevent contamination of the periphery of the copy paper, and a thin plate of metal or plastic painted white can be used. Furthermore, it is necessary that this shielding plate can be moved according to the size of the original to be copied, and by using two plates that can be moved in the vertical and horizontal directions, it is possible to easily achieve the desired purpose. can be achieved. This movement can be performed manually or using an electric motor. In addition, by selecting a flexible material for the shielding plate, the degree of freedom in design can be increased, and the number of shielding plates is not limited to two, but can be more than two, or even one. You can also do it.

Next, an example in which a manual switch is used as means for moving and stopping the shielding plate will be explained with reference to the drawings. FIG. 1 is a top view of an example of an electrophotographic copying apparatus according to the present invention, and FIG. 2 is a vertical cross-sectional view of a main part thereof.

Portions not directly related to the content of the present invention are omitted from illustration. In FIGS. 1 and 2, first, an original 3 to be copied is placed on a transparent original table glass plate 2. As shown in FIG.

Next, the switch 6 for moving the flexible shielding plate 4 is pressed. Only while this switch 6 is pressed, the electric motor 12 and the gear 13 connected to the switch rotate in the normal direction, and the end of the shielding plate 4 to which the rack 14 that meshes with the gear 13 is attached is moved along the guide 11. Move it to the left. When the shielding plate 4 reaches the edge of the original 3, the suppression of the switch 6 is released and the operation is stopped. On the other hand, when the switch 7 is pressed, the electric motor 12 rotates in reverse, and the end of the shielding plate 4 moves to the right.

Next, the preparation is completed by operating the switch 8-1: or 9 and moving the shielding plate 5 to the other end of the document 3, and then pressing the exposure switch 10 turns on the light source lamp 15. After that, copying is performed using a well-known electrophotographic method. Note that 1 in the figure is the main body of the device.

FIG. 3 is a top view showing another example of the present invention.

1\16 and 17 are switch groups for moving the shielding plate 4 and the shielding plate 6, respectively. In this case, a mechanism is selected in which the tips of the shielding plates 4 and 6 move to the position of the pressed switch in the switch groups 16 and 17, respectively, and then stop.

FIG. 4 is a top view showing still another example of the present invention, in which a pair of optical sensors 18 are installed at the tips of the shielding plates 4 and 6, respectively.
19 and 20.21. That is, when the original 3 is placed at a predetermined position on the original table glass 2 and the exposure switch 1o is pressed, the shielding plates 4 and 5 begin to move, the optical sensors 18 and 2o are hidden behind the original 3, and the optical sensors 19 and 21 This is an example of automation in which the image forming apparatus stops at the exposed position, and then the exposure and subsequent copying operations are performed.

As described above, the present invention makes it possible to make good copies without having to perform a cover operation using a document table cover as in the conventional case. In addition, on the manuscript table cover.

Since it may have the effect of bringing wrinkled originals into close contact with the glass, it is desirable to use the shielding plate according to the present invention depending on the condition of the original.

Furthermore, the basic idea of the present invention is to use a movable shielding plate, and the mechanism for driving the shielding plate, detecting the stop position 9, etc. may be any mechanism other than those shown in the figures as long as it is suitable for the type and structure of the electrophotographic copying apparatus. Of course, you can choose one. For example, it goes without saying that a method of determining the copy paper size from the paper feed cassette and driving and stopping the shielding plate depending on the paper feed cassette can also be adopted.

[Brief explanation of drawings]

FIG. 1 is a top view showing an example of an electrophotographic copying apparatus of the present invention, FIG. 2 is a vertical cross-sectional view of a main part thereof, and FIGS. 3 and 4 are two-sided views showing other examples of the present invention, respectively. It is. DESCRIPTION OF SYMBOLS 1... Apparatus main body, 2... Original table glass, 3... Original, 4, 6... Shielding plate, 6
,7,8゜9.10...e switch, 11...
...Guide, 12...Electric motor, 13...
...gear, 14...ranori, 16...
Light source lamp, 16.17-...Switch group, 18
~21... Original sensor. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2

Claims (1)

[Scope of Claims] (1) Moves on a plane parallel to the document glass to cover a portion of the document glass that is not occupied by the original to be copied, and reflects the light from the exposure light source inward. An electrophotographic copying apparatus characterized in that a shielding plate having a function of preventing leakage of unnecessary light is provided between the document table glass and the light source. (b)) The stopping position of the shield plate after movement is determined by selecting a group of switches provided respectively along two adjacent sides of the document table glass. The electrophotographic copying apparatus according to item 1). (3) The electrophotographic copying apparatus according to claim (1), wherein the stopping position of the shield plate after movement is determined by detecting the dimensions of the original or copy paper to be copied.