JPS6287981A - Copying device - Google Patents

Abstract

PURPOSE:To obtain constant images independently of the length of a leaving time by forming a selenium group photosensitive body and a destaticizing lamp and controlling respective elements so that the destaticizing lamp is lighted up for a fixed period when a main switch of a copying device is turned on to irradiate the rotating photosensitive body. CONSTITUTION:After setting up an original on an original platen and pressing the original by a platen cover 15, the number of copies is inputted from ten keys 14 and a copy starting button 11 is depressed, so that the photosensitive body 1 and a developing device 4 are rotated in the arrow A and B directions respectively, a high voltage is impressed to an electrostatic charger 2, a transfer charger 5 and a paper separating charger 6 and an inter-image erasing lamp 8, the destaticizing lamp 9 and an auxiliary exposure lamp 10 are simultaneously turned on. The lamp 10 is turned off after lighting for 1sec, the lamp 8 is also turned off after lighting for 2.5sec and the original image is exposed to the surface of the photosensitive body 1 by an image exposing device 3 to form its latent image. The latent image on the surface of the photosensitive body 1 is developed by a developing device 4 and the developed image is transferred to copying paper fed in synchronism with the rotation of the photosensitive body 1 and inserted between the photosensitive body 1 and the charger 5. Consequently, copies with almost constant image density can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a copying apparatus such as an electrostatic transfer copying machine, which is office equipment.

(Prior art) A photoreceptor has the disadvantage that when it is used repeatedly, its surface potential decreases as the number of uses increases.Therefore, there is a problem in that the image density of copies that are continuously copied gradually decreases. Ta.

As a countermeasure to this problem, there are methods to apply light to the photoconductor immediately before charging starts copying, to give the photoconductor a state similar to fatigue in advance, and to keep the surface potential constant according to the number of copies, or to apply light to the photoconductor according to the number of copies. A method has been adopted in which the amount of light irradiated onto the body is gradually weakened (Japanese Patent Application Laid-Open No. 49-4337).

(Problems to be Solved by the Invention) However, these measures require complicated control to gradually change the amount of light irradiation according to the number of copies in order to keep the surface potential of the photoreceptor constant. Additionally, the degree of recovery from photoreceptor fatigue varies depending on whether it is immediately after the previous copying process or after a considerable amount of time has passed. There was a problem in that it required complicated control to change the amount of light.

The present invention solves the above problems, and by selecting the wavelength range of irradiation light that causes fatigue to the photoreceptor, the fatigue state is maintained for a long time, the surface potential is kept constant, and the number of copies is increased. A constant image can be obtained regardless of the length of time the image is left after copying. An object of the present invention is to provide a copying apparatus that does not require complicated control.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a selenium-based photoreceptor, a selenium-based photoreceptor with a wavelength of 380 nm to 600 nm, and 720 nm
Immediately after the main switch of the copying machine is turned on, the photoreceptor is rotated and its surface is irradiated with the above-mentioned static elimination lamp for a certain period of time immediately after the main switch of the copying apparatus is turned on.

(Operation) With the above configuration, the photoconductor is activated only when the main switch of the copying machine is turned on.

When irradiated with a static elimination lamp for a certain period of time, the irradiation light in the selected wavelength range produces fatigue that lasts for a long time. Irradiation control becomes unnecessary.

(Example) Embodiments of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a block diagram showing the main parts of a copying apparatus according to the present invention. 1, a developing device 4 that rotates in the direction of arrow B that visualizes the latent image, and a transfer charger 5 that transfers the developed image onto copy paper. , a paper separation charger 6 that peels off the copy paper after the transfer from the surface of the photoreceptor 1;
A cleaning device 7 for removing developer remaining on the surface of the photoreceptor 1 after transfer is provided, and an inter-image erasing lamp 8 is provided after the charger 2. A static elimination lamp 9 and an auxiliary exposure lamp 10 are installed in front of the cleaning device 7, respectively.

Note that the photoreceptor 1 described above is a selenium-based photoreceptor made of arsenic and selenium. The inter-image erasing lamp 8 is a light emitting diode (L
The static eliminating lamp 9 emits light with a wavelength of 380 nm to 600 nm and 720 nm or more to erase the surface of the photo conductor 1 that has been cleaned. Electrostatically uniform. The auxiliary photosensitive lamp 1o is a tungsten light bulb, and when a copy start button 11, which will be described later, is pressed, the auxiliary photosensitive lamp 1o is turned on for a certain period of time and irradiates the photosensitive member 1. Although not shown in the figure, a copy paper supply device and a fixing device for images transferred thereto are provided.

FIG. 2 is a perspective view of the above-mentioned copying apparatus.The copying apparatus has a main switch 13. A numeric keypad 14 for setting the number of copies and a copy start button 11 are provided, and a platen cover 15 for holding down the document placed on the document table is also attached. The main switch 13 is a switch that turns on the power of the copying device. When turned on, preparations for copying will be completed after a certain period of time. 6 Copy start button 11 commands the copying device that has completed copying preparations to start copying. It is something to do. Therefore, main switch 1
3 and the copy start button 11 have different roles.

Regarding the operation of the copying apparatus having such a configuration, two control methods and their functions will be explained.

In the first embodiment, first, the main switch I of the copying machine is
3, the fuser (not shown) starts to be energized,
A fuser indicator lamp (not shown) provided in the copying apparatus main body 12 flashes, and at the same time, the photoreceptor 1 and the developing device 4 begin to rotate in the directions shown by arrows A and B, respectively.
The static elimination lamp 9 lights up. After about 40 seconds, the photoreceptor 1 and the developing device 4 stop rotating, and the static elimination lamp 9 goes out.

On the other hand, the fuser continues to be energized, and when it warms up to the set temperature, the energization stops and the fuser indicator lamp (not shown) goes out.
Displays copy preparation complete. It takes approximately 4 minutes to complete the copy level.

Next, place the original on the original table and press it with the platen cover 15, then input the number of copies using the numeric keypad 14, and press the copy start button 1.
Press 1. When the copy start button 11 is pressed, the photoreceptor 1 and the developing device 4 begin to rotate in the directions of arrows A and B, respectively, and a high voltage is applied to the charger 2, transfer charger 5, and paper separation charger 6. , and at the same time the inter-image erasing lamp 8. The static elimination lamp 9 and the auxiliary exposure lamp 10 are turned on. The auxiliary exposure lamp 10 is turned on for 1 second, the inter-image erasing lamp 8 is turned on for 2.5 seconds, and then turned off. At the same time, the image of the document is irradiated onto the photoreceptor 1 by the image exposure device 3, and a latent image is formed. Photoreceptor 1
The latent image on the surface of is visualized by the developing device 4, and a copy sheet fed in synchronization with the rotation of the photoreceptor 1 enters between the photoreceptor 1 and the transfer JiF M1 device 5 and is transferred. The copy paper on which the image has been transferred is peeled off from the photoreceptor 1 by the action of the one-sheet separation charger 6, fixed by a fixing device (not shown), and discharged as a copy. On the other hand, photoreceptor 1
After the developer remaining on the surface of the developer is cleaned by the cleaning device 7, it is made electrostatically uniform by the static eliminating lamp 9, and the same cycle is repeated again.

Therefore, when a plurality of sheets is set, the main rotation of the photoreceptor 1 and the developing device 4 continues, and the charger 2, transfer charger 5,
High voltage continues to be applied to the paper separation charger 6, and the static elimination lamp 9
remains lit. However, the inter-image erasing lamp 8 blinks in synchronization with image irradiation, and the auxiliary exposure lamp 10
It lights up for only 1 second after 1 is pressed.

Note that the method for starting copying is exactly the same whether copying one sheet at a time or multiple sheets at a time, and there is no need to change the light intensity of the static elimination lamp 9 or the auxiliary exposure lamp 10. There is no need to change it depending on the length of time it is left. This is because the static elimination lamp 9 lights up for about 40 seconds when the main switch 13 is turned on, causing continued fatigue on the photoreceptor 1, and the next time copying is performed, the surface potential of the photoreceptor 1 This is because it remains almost constant.

Furthermore, when the main switch 13 is turned on, the photoconductor 1 and the developing device 4 rotate together, and the developer adhered to the surface of the photoconductor 1 by van der Waalska acts as a lubricant, causing the contact between the cleaning device 7 and the photoconductor 1 to rotate. reduce friction between

The cleaning device 17 also has the function of removing moisture and other foreign matter adhering to the photoreceptor 1 after the copying operation is completed.

In this way, when you press the copy start button 11, you can copy from the first copy.
A clean copy with no fogging in the margins was obtained up to the 0th page.

In the second embodiment, using the same copying apparatus as in the first embodiment, first, when the main switch 13 of the copying apparatus is turned on, power supply to the fixing device (not shown) is started.

A fuser indicator lamp (not shown) provided on the copying apparatus main body 12 flashes, and at the same time, the photoreceptor 1 and the developing device 4 begin to rotate in the directions shown by arrows A and B, respectively.
A high voltage is applied to the charger 2 to start corona discharge, and the static elimination lamp 9 and the inter-image erasing lamp 8 are turned on. After about 60 seconds, the photoreceptor 1 and the developing device 4 stop rotating, the high voltage applied to the charger 2 is cut off, and the static elimination lamp 9 and the inter-image erasing lamp IO are turned off. On the other hand, the fuser (not shown) continues to be energized, and after about 4 minutes, when the temperature reaches the set temperature, the energization is stopped, and the fuser indicator lamp (not shown) stops blinking and the copying You will be notified that the preparation operation has been completed.

Under the above preparatory operations, even when the copy start button 11 was pressed, clean copies with no fogging in the margins were obtained for all copies from the first to the tenth. Furthermore, even if you press the copy start button 11 after leaving it for 60 minutes, 10 copies will be made from the first copy.
I was able to obtain clean copies with no overlapping in the margins for each copy.

In order to compare with these first and second embodiments, when the main switch 13 was turned on, only the fuser (not shown) was energized, and the copy preparation operation was completed when the temperature reached the set temperature. When the copy start button 11 was pressed, 10 copies were obtained using the same process as in the first embodiment. The first to third copies had a lot of fogging in the margins, and the fourth to 10th copies showed no change. The image density of the black portion of the first to tenth copies was constant at approximately 1.25.

(Effects of the Invention) As explained above, according to the present invention, the wavelength is 38 Or
+m to 600nm and a static elimination lamp that emits light of 720nm or more is used to irradiate the photoreceptor, which rotates once only when the main switch is turned on, to fatigue the surface of the photoreceptor, thereby making it almost constant during subsequent copying operations. A copy of the image density is obtained. moreover.

The photoreceptor can be irradiated only when the main switch of the copying device is turned on, and there is no need to change the amount of light depending on the number of times the photoreceptor is used, and the control can be extremely simple.

The fatigue given to the photoreceptor when the main switch is turned on is 4.
．． It has been confirmed that it lasts for 5 hours.

Therefore, even if the copying apparatus is used intermittently, the static elimination lamp is turned on and the photoreceptor is irradiated each time copying is performed, so that the fatigue state of the photoreceptor is maintained at an appropriate level, and a practically constant number of copies can be obtained. When the photoconductor is not used for a long period of time, such as at night or on holidays, the fatigue will recover, but the main switch will always be turned off at that time. The photoreceptor is subjected to fatigue conditions.

As described above, according to the present invention, it is possible to provide a copying apparatus that can always produce beautiful copies with constant image density without requiring complicated control.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the main parts of a copying apparatus according to the present invention, and FIG. 2 is a perspective view of its external appearance. DESCRIPTION OF SYMBOLS 1... Photoreceptor, 2... Charger, 3... Image exposure device, 4... Developing device, 5... Charger for transfer, 6... Charger for paper separation, 7... ...Cleaning device, 8. Inter-image erasing lamp, 9.. Static elimination lamp, 10.. Auxiliary exposure lamp, 11.. Copying start button. 12... Copying device body, 13... Main switch, 14... Numeric keypad, 15... Platen cover. Patent applicant: Matsushita Electric Industrial Co., Ltd. Figure 1 1 - Sad offering 2°・l! fL 翳3 Dethronement 4 Yuan Yatsuka 8 I trench F/I cleansing lamp ゛Fig.・・・Jin＼− 15゛Fadeshiba I

Claims (1)

[Claims] In a copying machine equipped with at least a photoreceptor and a static elimination lamp, a selenium-based photoreceptor and a wavelength of 380 nm to 600 nm are used.
Equipped with a static elimination lamp that emits light components of 720 nm and above, when the main switch of the copying machine is turned on,
A copying apparatus characterized in that the above-mentioned static elimination lamp is controlled to be lit for a certain period of time and to irradiate a rotating photoreceptor.