JPH03245166A - Electrophotographic copying device - Google Patents

Abstract

PURPOSE:To eliminate the variation of printing start position by varying a time from detecting a material to be transferred till starting exposure in accordance with the adjustment of a timer measuring time. CONSTITUTION:The time from detecting the material to be transferred by a detection means 13 until starting the exposure by an exposing means 5 is varied in accordance with the adjustment of the timer 35 measuring time by adjusting means 33 and 34. In the case deviation occurs at the printing start position on a paper, the time from detecting the material to be transferred by the detection means 13 until starting the exposure by the exposing means 5 is adjusted by the simple adjusting operation of the means 33 and 34 so as to correct the deviation. Thus, the variation of printing start position caused by the mechanical error, etc., of a system for conveying a material to be transferred is easily compensated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to electrophotographic devices such as printers and copying machines.

[Prior Art] As shown in FIG. 3, a conventional electrophotographic apparatus of this type has a charging section 4, an exposing section 5, and a developing section arranged around a photoreceptor 3 rotating in the direction of arrow M in the figure according to an electrophotographic process. 6. Transfer section 7
are arranged respectively, and the photoreceptor 3 is charged by the charging section 4.
Image information is formed as an electrostatic latent image in the exposing section 5, and the electrostatic latent image is developed into a visible image using toner in the developing section 6, and the image is transferred along a transport path (not shown) in the direction of arrow N in the figure. The visible image is transferred in the transfer section 7 onto the transferred material being conveyed.

In this device, a sensor 13 for detecting the transferred material is provided on the upstream side of the conveyance path, and the timing of the print sequence is controlled in accordance with the detection output of this sensor 13. That is, the exposure position of the photoreceptor 3 by the exposure unit 5 is A, the image transfer position of the transfer unit 7 to the transferred material is B, the mounting position of the sensor 13 is C, and the image transfer position it B is from the light position A. When the distance from the image transfer position B is Ll, and the distance from the sensor installation position C to the image transfer position B is L,
When the rotational speed of the photoreceptor 3 and the conveyance speed of the transfer material are equal, the transfer start position of the transfer material is at the position By starting exposure when the latent image is located, the leading edge of the latent image exposed at point A will coincide with the transfer start position of the transfer material at point B. Therefore, the time (-distance M
A timer is provided to measure the transfer speed (L2/transfer speed of the transferred material).
When the sensor 13 detects the transfer material, the timer starts counting, and when the timer times out, the exposure section 5 starts exposure.

[Problems to be Solved by the Invention] As described above, in the conventional electrophotographic apparatus of this type, the time from when the transfer material reaches the sensor 13 until the exposure section 5 starts exposing the photoconductor is short. is controlled to be constant by a timer, and exposure of the photoreceptor 3 is started in response to the timeout of this timer. However, in the conveyance system for the transferred material, slight deviations occur due to mechanical errors caused by each device. For this reason, the printing start position of the transfer material varies from device to device, and depending on the device, a suitable printing start position cannot be achieved and the product cannot be shipped. In such cases, the conveyance system was adjusted to ensure the quality of the product, but this required a great deal of man-hours and precision.

In view of this, the present invention allows the printing start position to be corrected due to mechanical errors in the transfer target conveyance system, etc. by arbitrarily adjusting the exposure start timing by the exposure means. - The purpose is to provide an electrophotographic device that can easily compensate for irregularities and ensure high quality products without requiring special effort.

[Means for Solving the Problems] An electrophotographic apparatus of the present invention includes a photoreceptor, an exposure means for forming an electrostatic latent image on the photoreceptor, and a developing means for developing the electrostatic latent image into a visible image. , 61; a transfer means for transferring a visual image onto a material to be transferred; a conveyance stage f-stage for the material to be transferred; a detection means for detecting the material to be transferred by the conveyance means; a timer means for starting time measurement in response to detection; an adjustment means for adjusting the time measured by the timer means; and an exposure means for starting exposure by the exposure means when the timer means measures the measurement time adjusted by the adjustment means. and a control means, the time from when the transfer material is detected by the detection means until the exposure is started by the exposure means can be varied according to the adjustment of the timer measurement time by the adjustment means. .

[Function] If such a measure causes a deviation in the printing start position on the paper, a simple adjustment operation of the adjusting means will cause the detecting means to detect the material to be transferred and then the exposing means By adjusting the time until the exposure starts, it is possible to correct the smearing.

[Example] The following is an example in which the present invention is applied to an EEH, an emitter, and a ray head.
I will explain while referring to j.

Figure 1 shows the overall structure of this embodiment device.
A tram is provided in the center of the printer body. This tram has 21 sections, including a photoconductor. This photoreceptor 3 is driven to rotate once in the , jj directions, and a charging means is applied around the photoreceptor 3 to uniformly electrify the photoreceptor 3 according to an electrophotographic process. c! an exposure device 5 as an exposure means for recording and forming an electrostatic latent image; a lower developing stage for applying toner, which is a developer, to the exposed photoreceptor 3 and developing a visual image; 1. a developing device 6, a transfer charger 7 as a transfer means for transferring the RIJ visual image onto a transfer material, a charge eliminating charger 7 for eliminating the charge 6:I remaining on the paper, and a photoreceptor 3.
A cleaner for removing toner from the photoconductor 3; a destaticizing device 9; and a discharging lamp for discharging the photoreceptor 3] are provided in this order. Near the front entrance of the transfer charger 7, there is a pickup roller 12 for feeding and transporting the transfer material stored in the paper feed section 11 toward the transfer charger 7 at a predetermined timing, and this pickup roller. ] A transfer material detection sensor 13 is provided to detect the conveyance, size, and jam of the transfer material picked up by the transfer material 2.

Further, behind the transfer charger 7, a thermal fixing device 14 and a uF paper roller 1516 for thermally checking the transferred material are provided in this order.

Further, inside the printer main body 1, there are conveyance plates 17,
The fan motor 18, DC type Fi, IQ, and V interlock switch 2[1 for detecting opening of the casing are discussed.

Here, the conveyance morph 17, the paper discharge row 71516, and the pickup roller 12 constitute a means for conveying the transfer material.

FIG. 2 is a block diagram showing a schematic circuit configuration of this embodiment device, in which 21 is a CPU (central processing unit) that constitutes the main body of the control unit, 22 is program data and various tables etc. used by this CPU 21 to control each part, etc. ROM with
(read-only memory), 23 is a RAM (random access memory) that stores image information and various processing data sent from an external host computer;
24 is the I10 boat, these are the pass line 25
connected by.

The I10 boat 24 includes a motor drive circuit 26 for driving and controlling the transport motor 17, a high voltage power supply circuit 27 for supplying high voltage to the exposure device 5, the charger 4 and the transfer charger 7, and A toner sensor circuit 30 that receives signals from the two provided toner empty sensor 28 and two toner full sensors. An operation panel 31 as an operation section, the transfer material detection sensor 13, the fan motor 18, an interface 32 for receiving image information from a host computer, and first and second dip switches 33 and 34 are connected, respectively. .

The interlock switch 20 is inserted into a 24y supply line connected to the DC type M, one motor drive circuit 26, the exposure device 5, the high voltage power supply circuit 27, and the fan motor 18, and is connected to the casing of the printer main body 1. It detects when the body is released and shuts off this 24y supply line.

Further, the CPU 21 has a built-in timer 35. As shown in FIG. 3, the exposure position on the photoreceptor 3 by the exposure device 5 is set to A, the image transfer position to the transferred material by the transfer charger 7 is set to 81, and the mounting position of the transferred material detection sensor 13 is set to C1 exposure position. When the distance from A to the image transfer position B is Ll, and the distance from the sensor mounting position C to the image transfer position B is L, if the rotational speed of the photoreceptor 3 and the conveyance speed of the transfer material are equal, then , the transfer start position of the transfer material is detected by the sensor 13.
Distance from ML2 (L-Ll' + Ll-Ll')
By starting exposure when the material is at the transported position X, the beginning of the latent image exposed at point A will coincide with the transfer start position of the transfer material at point B. . Therefore, the timer 35 is set to measure the time (-distance ML2/conveying speed of the transferred material) from when the sensor 13 detects the transferred material until the transfer start position of the transferred material reaches position lfx. In response to the sensor 13 detecting the transfer material, the timer 35 starts counting time, and when the timer 35 times out, the exposure device 5 starts exposure.

By the way, the time measured by the timer 35 is the same as the first.
It is variably set by the on/off combination of the second dip switches 33 and 34.

This is done by forming a timer data table 40 in the ROM 22, as shown in FIG. Sometimes the first.
The timer data corresponding to the states of the second dip switches 33 and 34 is read out from the table 40 and stored in the RAM 23.
This is possible by writing the data into the timer 35 and using the data as the counting time of the timer 35.

That is, the CPU 21 is program-controlled to execute the processes shown in the flowcharts of FIGS. 5 and 6. When the power is turned on, first the first. Read the states of the second dip switches 33 and 34. Next, the RO
With reference to the timer data table 40 of M22, the first
．． The timer data corresponding to the states of the second dip switches 33 and 34 is read out and stored in the RAM 23. Thereafter, when printing is started, the timer data in the RAM 23 is set in the timer 35. Further, as a pre-print process, the photoreceptor 3 is charged by the charger 4, and the pickup roller 12 is driven to pick up the transfer material from the paper feed section 11.

Then, when the transferred material picked up by the pickup roller 12 is detected by the transferred material detection sensor 13, a timer is started. As a result, an interrupt is generated to the CPU 21 at the timer cycle, and each time this interrupt occurs, the timer data of the timer 35 is
-1" increments.

) and set the timer data of the upper self timer 35 to "0"
When the CPU 21 detects that the exposure bag W5 has reached , the CPU 21 starts exposure using the exposure bag W5 to form image information as an electrostatic latent image on the photoreceptor 3, and then executes a series of print sequences.

The above process is repeated every time printing starts until the power is turned off.

As described above, in this embodiment, the first . By operating the second dip switches 33 and 34, the time from when the transfer material detection sensor 13 detects the transfer material until the exposure device 5 starts exposure can be variably set. Now, one count of timer 35 is 10m
5, for example, when the first dip switch 33 is turned off and the second dip switch 34 is turned on, the timer data is set to 51 and the measurement time is 510 seconds. At this time, assuming that the distance MLI from the exposure position A to the image transfer position [B and the distance [L1' from the transfer position B to the position 1'X where the exposure starts] are equal, the first
．． When both the second dip switches 33 and 34 are turned "off", "48" is set as the timer data, the measurement time is shortened by 480111 seconds, and the distance 111LI' becomes 1 mm longer than the distance L1. In other words, the exposure device 5 starts exposure at a point where the distance L2 from the sensor position C is 11 cm shorter. Similarly, turn on the first dip switch 33 and turn on the N2 dip switch 3.
4 is set to ``off'', the timer data is set to ``54'', the measurement time becomes 540m5, and the distance Ll'
is 11II shorter than the distance L1. In other words, at a point where the distance L2 from the sensor position C is 1+u+ longer, the exposure device 5
exposure is started. 1st. When both the N2 dip switches 33 and 34 are turned on, the timer data is set to 57, the measurement time is 570 m5, and the distance 111tL1' is 2 mm shorter than the distance L1. That is, the distance L2 from the sensor position C is 2+nm.
Exposure by the exposure device 5 is started at the long point.

Generally, there is only a slight deviation in the conveyance system of the transferred material due to mechanical error depending on each device, and this slippage causes variations in the printing start position of the transferred material. This variation in printing start position can be adjusted by setting the second dip switches 33 and 34. Therefore, the manufacturer can easily adjust the irregularity of the printing start position to IJ1 at the time of shipment, thereby ensuring high quality of the product.

Further, the printing start position may shift due to changes over time during use, but correction in this case can be easily performed.

It goes without saying that the present invention is not limited to EEH printers, but can be applied to general electrophotographic devices such as laser printers and copying machines.

[Effects of the Invention] As described in detail above, according to the present invention, by arbitrarily adjusting the exposure start timing of the exposure means, it is possible to easily eliminate variations in the printing start position due to mechanical errors in the transfer material conveyance system, etc. It is possible to provide an electrophotographic device that can compensate for the damage and ensure high quality products without requiring special effort.

[Brief explanation of drawings]

The figures show an embodiment in which the present invention is applied to an EEH printer, in which Fig. 1 is a structural diagram of the EEH printer, Fig. 2 is a circuit diagram of the EEH printer, and Fig. 3 is a timer setting time. FIG. 4 is a diagram for explaining the configuration of a timer data table formed in the ROM, and FIGS. 5 and 6 are flowcharts showing the main program processing of the CPU. 3... Photoreceptor, 4... Charger, 5... Exposure device (n light means) 6... Developing device (developing means) 7.
. . . Transfer charger (transfer means), 12 . . . Pick up roller, 13 . CPU (exposure control means) 33°34・
...First. Second dip switch (adjustment means), 35
...Timer (timer means), 40...Timer data table.

Claims (1)

[Claims] a photoreceptor, an exposure means for forming an electrostatic latent image on the photoreceptor, a developing means for developing the electrostatic latent image into a visible image, and a transfer means for transferring the visible image onto a transfer material; a conveyance means for the transfer material; a detection means for detecting the transfer material conveyed by the transfer means; and a timer means for starting time measurement in response to the detection of the transfer material by the detection means; It comprises an adjusting means for adjusting the measurement time by the timer means, and an exposure control means for starting the exposure by the exposure means when the timer means measures the measurement time adjusted by the adjusting means. An electrophotographic apparatus characterized in that a time period from when a transfer material is detected to when exposure is started by the exposure means is varied in accordance with adjustment of a timer measurement time by the adjustment means.