JPS6197666A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To obtain high-quality electrophotographs from the begining, by adjusting the sensitivity of a photosensitive body by operating an electrostatic charge section and destatizing section while the photosensitive body rotates by a prescribed quantity after power supply is made. CONSTITUTION:When a power supply is turned on, destatiazing lamp 8, charger 3, and photosensitive body 2 are turned on in the described order and, after the photosensitive body 2 is rotated by a prescribed number of times, the charger 3 and lamp 8 are turned off and the surface potential of the photosensitive body 2 becomes lower. Then ordinary main processing is started. When the power supply is again made after it is once turned off, the main processing is started by operating a specific switch and thus, the main processing operation is quickly started. Since the sensitivity of the photosensitive body is lowered to the same condition as that when the photosensitive body is used one or two times, high-quality printing which is uniform in brightness can be performed from the begining.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention includes at least a charging section, an exposing section, a developing section, and a static eliminating section arranged in sequence along the direction of movement of the surface of a photoreceptor, and the charging section is charged. The present invention relates to an improvement in an electrophotographic apparatus in which an image is formed on the photosensitive surface of a photoconductor in an exposure section, roughly developed in a development section to obtain a photographic image, and the photoconductor is neutralized in a discharging section to prepare for the next charging.

[Prior Art] Conventionally, in this type of electrophotographic apparatus, exposure and development were performed sequentially without taking any measures to prevent the surface potential of the photoreceptor from becoming abnormally high due to charging by the charging section. It was used to obtain electronic photographs.

[Problems to be Solved by the Invention] By the way, in this type of device, when the photoconductor is in a new state, and when it is used for the first time or after not being used for a while, it is difficult to clean the photoconductor for the first few sheets. The sensitivity may become too good and the surface potential due to charging may become abnormally high. However, in such a case, the above-mentioned conventional apparatus has a problem in that image formation by exposure is insufficient, resulting in an electrophotograph that is too dark, making it impossible to obtain a high-quality electrophotograph.

This invention was made to solve this problem. When the power is turned on, the photoreceptor is automatically charged and removed until it rotates a predetermined amount, lowering the sensitivity of the photoreceptor, and reducing the surface of the photoreceptor. To provide an electrophotographic device that can prevent an abnormally high potential and immediately start an electrophotographic production operation with a simple operation when there is no need to lower the sensitivity of a photoreceptor.

[Means for Solving the Problems] This invention provides at least a charging section, an exposing section, a developing section, and a static eliminating section arranged in sequence along the moving direction of the surface of the photoconductor, and the photoconductor charged in the charging section. In an electrophotographic apparatus in which an image is formed on the photoreceptor surface in the exposure section and further developed in the development section to obtain a photographic image, the photoreceptor is neutralized in the charge removal section and waits for the next charging, when the power is turned on. A photoconductor sensitivity adjustment means that operates a static charge removal section together with a charging section until the photoconductor rotates a predetermined amount prior to an electrophotographic creation operation, and a switch that is operated at the same time when the power is turned on and prohibits control by the photoconductor sensitivity adjustment means. It has been established that

[Function] In the present invention having such a configuration, if the switch is not operated when the power is turned on, the sensitivity of the photoreceptor is increased by charging and eliminating static electricity until the photoreceptor rotates a predetermined amount prior to the operation of creating an electrophotograph. When the voltage is lowered and this processing is not required, by operating a switch when the power is turned on, preliminary charging and neutralization are prohibited, and an electrophotographic production operation can be started immediately.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

In this embodiment, the present invention will be described as applied to an electrophotographic printer using a laser.

FIG. 1 shows the overall configuration, and 1 is a casing. A photosensitive drum 2 as a photosensitive member having a photosensitive surface formed along the outer periphery is installed in the center of the housing 1, and the photosensitive drum 2 is rotated at a constant speed by a motor (not shown). Along the circumference of the photosensitive drum 2,
A charger 3 forming a charging section, a generator 5 for scanning laser beam 4 forming an exposure section, a developing section 6, a transfer section 7 having a transfer charger, a static elimination lamp 8 forming a snow removal section, and a wiping roller 9 are provided. has been done.

An insertion slot 1 for a paper feed cassette 10 is provided at the lower side of the housing 1.
1 is formed between the insertion opening 11 and the transfer section 7, and a paper feed roller 13 and a paper feed id 1 for guiding the paper 12 stored in the paper feed cassette 10 to the transfer section 7.
4 is provided.

Note that a paper insertion section 15 for manually feeding paper is also provided on the side surface of the housing 1.

On the opposite side of the transfer section 7 to the paper feed guide 14, there is a conveyor 16 and 2° fixing rollers 17a, 1.
A fixing section 18 consisting of 7b is provided.

As shown in FIG. 2, the laser beam generating device 5 includes a laser light emitting element 51 that is turned on and off according to information;
A rotating polygon mirror 52 and an fθ lens 53 that horizontally scan the laser light from the light emitting element 51, a scan start position sensor 54, a scan end position sensor 55, and each sensor 54, 55 are irradiated with laser light, respectively. Reflecting mirrors 56 and 57 direct the laser beam to the photosensitive drum 2.
and a mirror 58 for directing the light to the photosensitive surface.

FIG. 3 is a block diagram showing the circuit configuration, in which 21 is a CPLI (central processing unit) that constitutes a control section, 22 is a CP (J
21 is a ROM (read only memory) in which program data for controlling each part is stored; 23 is a character generator; 24 is an area for storing information for printing; an area for storing flags for control; A RAM (random access memory) in which a counter etc. are formed, 25 an interface for taking in information from the outside, 26 various sensors 27 such as the scan start sensor 54 and the scan end sensor 55, the static elimination lamp 8, etc. various lamps 28, the charger 3,
Various chargers 29 such as a transfer charger, various motors 301 such as a motor for rotationally driving the photosensitive drum 2 and a motor for rotationally driving the rotating polygon mirror 52, and input/output control for various key switches 31 such as a print start key switch are performed. This is an I10 port that controls the output of information to the laser beam generator 5. Said CPU2
1, ROM 22, character generator 23, RAM
24, interface 25, and I10 boat 26 are connected by a path line 32. The cpu2i
stores the information inputted from the outside via the interface 25 in the RAM 24, and when the information is to be printed later, the information is converted into character pattern information by the character generator 23 and then sent via the board 26. The output to the laser beam generator 5 is controlled. Further, the CPU 21 selectively controls various sensors 27, various lamps 28, various chargers 29, various motors 30, and various key switches 31 via the I10 port 26 based on program data in the ROM 22.

FIG. 4 shows the main control performed by the CPLI 21. When the power is turned on, initial processing such as RAM clearing is first performed, and then a specific key switch among the various key switches 31 is selected, e.g. Check whether the print start key switches are operated at the same time. If this specific key switch operation is not performed at the same time, the static elimination lamp 8 is turned ON, and the static electricity charger 3 is turned ON.
, the photosensitive drum 2 is sequentially rotated. Next, a time counting operation is started, and the photosensitive drum 2 rotates a predetermined number of times (for example, 1~
Count the time required to complete the rotation (approximately 2 rotations). When the time has elapsed, the charger 3 is set to 0FFL, and the static elimination lamp 8 is turned off. In this manner, an operation is performed to lower the surface potential of the photosensitive drum 2 before entering the main process. When this operation is completed, main processing is started. Furthermore, if a specific key switch operation is performed at the same time as the power is turned on, the sensitivity adjustment operation for the photosensitive drum 2 is prohibited and the main processing is immediately started. In the main process, an image of information is formed on the surface of the photosensitive drum 2 using a laser beam from a laser beam generator 5, followed by development with toner in a developing section 6, and then an image is formed from a paper feed cassette 10 in a transfer section 7. The image is transferred to the fed paper, and the transferred paper is roughly fixed by the fixing row 517a117b and then discharged to the outside. In this way, paper on which information is printed is obtained through the main processing.

In the apparatus according to the embodiment of the present invention having such a configuration, when the power is turned on without operating a specific key switch, the charger 3 and the neutralization lamp 8 are automatically operated prior to the information printing operation, and the photosensitive drum 2 is Just for printing 1
It will be in the same state as when it has been used twice, and the sensitivity of the photosensitive surface will decrease, and the surface temperature will decrease. Therefore, when actually printing on paper, image formation by laser exposure can be performed well, and the brightness of the paper is almost constant from the beginning, making it possible to perform high-quality printing and always producing high-quality electrophotography. Obtainable. Also, once turn off the power
Ft... If you turn on the power again after a relatively short period of time, there is no risk that the sensitivity of the photosensitive surface of the photosensitive drum 2 has increased abnormally, so in this case, operate a specific key switch to turn on the power. throw into. As a result, the main processing is performed immediately after the initial processing, and the printing operation can be started quickly.

In the above embodiments, the present invention was applied to a laser electrophotographic printer, but the present invention is not necessarily limited to this, and can also be applied to a normal copying machine.

[Effects of the Invention] As detailed above, according to the present invention, when the power is turned on, the photoreceptor is automatically charged and neutralized until it rotates a predetermined amount to lower the sensitivity of the photoreceptor and increase the surface potential of the photoreceptor. Therefore, it is possible to provide an electrophotographic apparatus which can prevent an abnormally high level of the photoreceptor from becoming abnormally high and can immediately start an electrophotographic production operation with a simple operation when there is no need to reduce the sensitivity of a photoreceptor.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, and FIG. 1 is a diagram showing the overall configuration, FIG. 2 is a perspective view showing the configuration of the laser beam generator, FIG. 3 is a block diagram showing the circuit configuration, and FIG. The figure is a flowchart showing main control by the CPU. 2... Photosensitive drum (photoreceptor), 3... Charger (charging section), 5... Laser beam generator (exposure section), 6... Developing section, 8... Static elimination lamp (static elimination section) ),
2l-CPU (central processing 1itu>, 22-ROM(
Read-only memory), 24...RAM (Random Access Memory), 31...Various key switches. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] At least a charging section, an exposing section, a developing section, and a static eliminating section are sequentially arranged along the moving direction of the surface of the photoreceptor, and the exposing section forms an image on the photosensitive surface of the photoreceptor charged by the charging section. Further, in an electrophotographic apparatus in which a photographic image is obtained by developing in the developing section, and the photoreceptor is neutralized in the static eliminating section to wait for the next charging, when the power is turned on, the above-mentioned step is performed prior to the electrophotographic creation operation. A photoconductor sensitivity adjustment means for operating a static eliminating section together with the charging section until the photoconductor rotates by a predetermined amount, and a switch that is operated at the same time when the power is turned on and prohibits control by the photoconductor sensitivity adjustment means. An electrophotographic device featuring: