JPS60209757A - Side-unnecessary image erasing device of electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To obtain the proper quantity of image erasure in any feed mode and to prevent the formation of black stripes at an end part by recognizing previously the proper quantity of image erasure in every feed mode and changing the quantities of image erasure according to a change in mode. CONSTITUTION:When a copy is taken by using a form of, for example, B4 size, an image outside an image area is all erased preferably. When the specified side of a drive controller 23 is B4, constant currents are supplied to light emitting diodes L1, L2, L60, and L61. At this time, when the feed mode of an original is a manual mode, the operation signal from an automatic original feeding mechanism 24 is turned off and a feed mode switching adjusting device 25 performs current control in manual feed mode to control the current flowing to a constant current source 22. When an original is sent by the automatic original feeding mechanism 24, the operation signal from the mechanism 24 is inputted to the feed mode switching adjusting device 25 to perform the current control in automatic feed mode, and its operating current is controlled so that the arrival range of irradiation light from the light emitting diodes L1, L2, L60, and L61 is expanded as compared with that in manual feed mode.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a side unnecessary image erasing device for an electrophotographic copying machine. Bolt the wound.

[Prior art]

A typical electrophotographic copying machine is as shown in Figure 1.
As the photoreceptor drum 1 rotates, the charged corotron 21 first
As a result, charges are uniformly applied to the surface of the photoreceptor drum 10,
Next, the W and Kn 4 placed on the platen 3 are connected to the light source 5.
The reflected light 6 at this time is reflected (mu 7).
The light is made incident on the photoreceptor drum through an optical system composed of lenses a, 7b and a non-optical lens 8, to form an electrostatic latent image on the surface of the photoreceptor drum corresponding to the image information of the document. This electrostatic a image is made visible by a developing device 9, and the resulting toner image is transferred by a corotron 10 to a loaded paper 11 (((transferred). After transfer, the photosensitive drum 1 itself and the remaining toner on the surface of the photoreceptor drum is neutralized by the corotron 12, and the residual toner on the surface of the photoreceptor drum is removed by the cleaning device 13. After this, static electricity is removed. Irradiating the surface of the photoreceptor drum 1 with the lamp 14,
The photoreceptor drum 1, which has been completely neutralized, is returned to its pre-charged state.
This allows the photosensitive drum to be used repeatedly.

In this way, the process returns to the first step of charging and applying a charge using the corotron 2, and the edge-flipped copying is continued.

By the way, when an electrostatic latent image is formed on the surface of a photoreceptor drum by reflected light from an irradiated document, variations in the distribution of charges applied to the photoreceptor drum,
Or, due to errors in light collection during light irradiation,
Images may be formed on unnecessary parts such as the ends of the photoreceptor drum. This not only results in forming an unnecessary image on the recording paper, but also often causes problems in subsequent steps if the image remains on the photoreceptor drum without being transferred.

Therefore, a side unnecessary image erasing means is used for erasing the electrostatic latent image formed in the unnecessary portion with light from a light emitting diode before it is visualized by the developing device.

As shown in Fig. 2, for example, 61 light emitting diodes labeled Ll...L6° and arranged in a row parallel to the main scanning direction erase images between rows and sides. Device 15 (Inter and Side
Image Lamp Assembly - Below 15
A method has been used to eliminate side non-absorption using an IL assembly (commonly referred to as an IL assembly).

For example, as shown in FIG. 3, on the surface of the photoreceptor drum 1,
Ll, L2, and L5o..." When attempting to erase the electrostatic latent image in unnecessary parts on the side by irradiating with 14 light emitting diodes of 61, the image is The distances S1 and S2 to the inner edge of the erasable area vary depending on the potential of the sensitive material on the photosensitive drum, the luminous efficiency, and the current If flowing through the light emitting diode.Therefore, the unnecessary image erasing range from the paper width W to the side ( Image erasure amount) & 1+ &
The area excluding 2 becomes the image area R. Here, since the potential of the sensitive material changes depending on the document, it cannot be controlled, but various measures have been taken to control the amount of light from the light emitting diode in order to keep the image area R constant. For example, when performing normal copying, methods such as using a constant current power supply to control the current flowing through the light emitting diode, or strictly selecting parts to keep the light emitting efficiency of the light emitting diode constant, is adjusted so that the amount of image erasure is constant and is outside the image area R.

By the way, when using an automatic document feeder, if there is an extra feed or a misalignment of the registration lane,
This is an unavoidable phenomenon, but if you adjust the side image erasure amount for normal copying (when not using the automatic document feeder), if the document is shifted diagonally due to automatic feed,
There was an inconvenience that black streaks appeared on the copy.

On the other hand, if the side erase amount is adjusted to be large for automatic document feeding, there is a problem that the erase amount is too large for normal copying.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and it adjusts the amount of image erasing to an appropriate value in any of the cases of W, automatic document feed mode, and normal copy feed mode, and To provide a side unnecessary image erasing device capable of obtaining beautiful copies without generating black streaks.

[Structure of the invention]

In order to achieve the above object, the side unnecessary image erasing device of the present invention recognizes in advance the relationship between the appropriate image erasing light in the automatic feed mode and the appropriate image erasing light in the feed mode for normal copying. Depending on the relationship,
An image erasing amount control device is provided which is configured to change the image erasing amount as the mode is changed.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

This side unnecessary image erasing device is as shown in Figure 4.
61 light emitting diodes L1...L6. are arranged in a row parallel to the main scanning direction, and these light emitting diodes L19. ．． Constant current power supply 2 for independently supplying constant current to L61
2, and a drive control device 23 for controlling the blinking of these light emitting diodes L1...L61.

Furthermore, this drive control device 23 operates in the normal case (when the automatic document feed mechanism does not operate and the oiler sets the document) while the activation signal is input from the automatic document feed mechanism 24. The transmission mode switching adjustment device 25 includes a built-in microcomputer that controls the current value If to be multiplied by a predetermined value and to increase the current value If.

Next, a side wave image erasing operation using this side unnecessary image erasing device will be explained.

First of all, when carrying out a selvage using B4 size paper, it is desirable to erase all images outside the image area R1, as shown in FIG. Assuming that the size of the drive control device is 84, the spring diode L1. L2. L6olL6. (If the document feed mode is set to manual at this time, the operation signal from the automatic document feed mechanism 24 is turned OFF), and the feed mode switching adjustment device 25 controls the current flowing through the constant current power supply 22 by controlling the current in the manual transmission mode.

Further, when the original is fed by the automatic original feeding mechanism 24, an activation signal from the automatic original feeding mechanism 24 is input to the feeding mode switching adjustment device 25. Turn off the corresponding mode! The L1 change adjustment device 25 performs current control in the automatic transfer mode, and controls the light emitting diodes L4. L2. L6o, L
61 operating type 1 streams are controlled.

In this way, the light emitting diode "11" 2 is lit.
The side defective image is erased by the irradiation light "601" 61. Image erasure fi' A 1 + a 2 at this time
(Distance from the edge of the paper to the image area) I'i In the normal feeding mode, < a 1 , as shown in Fig. 6(a).
a2"""l In the case of automatic feeding mode, the 6th (
b) As shown in the figure, a, , a2=5+m. Even in the automatic feed mode, it is possible to obtain beautiful copies without black streaks occurring at the edges of the copies.

Furthermore, in the case of normal feed mode, it is possible to widen the image area.

For comparison, an example is shown in which the automatic feed and normal feed are operated with the same current as in the past.The image erasure amount is 3. ! 5 mm, and in the case of automatic feeding, black streaks sometimes appeared at the edges of copies.

In addition, in the embodiment, a method of switching and controlling the operating current value If according to the mode has been described, but the method is not necessarily limited to this, and as shown in FIG. A movable partition plate C is provided inside the light emitting diodes arranged at the innermost side, and by moving this partition plate closer to or further away from the photoreceptor drum, the irradiated light from the light emitting diodes can reach. It is also effective to adjust the range.

〔Effect of the invention〕

As described above, according to the present invention, from among the light emitting diodes arranged in a row parallel to the main scanning direction, a predetermined number of light emitting diodes at both ends are turned on depending on the paper size to be used. However, in order to erase the uneasy electrostatic latent image prior to development, when the document is fed automatically, the irradiated light from the light emitting diode reaches the inside of the document, even when it is not normally fed. Because of this adjustment, even when using automatic paper feed, you can obtain powerful and beautiful copies with black lines at the edges of the copy, and when using normal paper feed, the image area It becomes possible to widen the area.

[Brief explanation of drawings]

FIG. 1 is a structural explanatory diagram of a general electrophotographic copying machine, FIG. 2 is a diagram showing a normal side unnecessary image erasing device, and FIG.
A diagram showing the erasure range of side non-absorption by the apparatus of FIG. 2,
Fig. 4 is a diagram showing a side unnecessary image erasing device according to an embodiment of the present invention, Fig. 5 is an explanatory diagram showing the mechanism of image erasing by the same device, and Figs. Figure 6(c) is a diagram showing the amount of image deletion when copied with the same device in the normal transfer mode and automatic transmission mode, respectively. The figure is a part of an explanatory diagram showing another embodiment of the present invention. 1... Photosensitive drum, 2... Charged corotron, 3...
... Noraten, 4... Manuscript, 5... Light source, 6...
Reflected light, 7a, 7b... Reflecting mirror, 8... Condensing lens, 9... Developing device, 10... Transfer corotron, 11
... Paper, 12 ... Static elimination corotron, 13 ... Cleaning device, 14 ... Static elimination lamp, 15 ... Side barren image erasing device, 21 ... 15IL assembly,
22... constant current power supply, 23... drive control device, 24
... Automatic document feed mechanism, 25 ... Feeding mode switching adjustment device, L, ... L61 ... Light emitting diode,
R, R...image area, aa...unnecessary image 1 1 l
2 Amount of erasure. Figure 1 4 knee j'4

Claims (1)

[Claims] Light-emitting diodes arranged in a row parallel to the main scanning direction are used to create a photoreceptor drum that carries an electrostatic latent image by lighting up a predetermined number of light-emitting diodes at both ends depending on the paper size used. Side unnecessary image f3 for erasing an unnecessary image of soil prior to development: an effective light irradiation area on the photoreceptor drum by the light emitting diode, depending on whether or not the automatic document feed mode is selected in the erasing device. An electrophotographic copying machine characterized in that a switching adjustment means for switching the switching mode is set to A, and when an automatic document feeding mode is selected, the reachable range of the irradiated light of the light emitting diode is expanded. The side of the slump was slightly removed.