JPH0312668A - Automatic registration adjusting device of paper feeder - Google Patents

Abstract

PURPOSE:To reduce the size of a registration detection sensor by moving the registration detection sensor to a passing position at a side end of recording paper according to the size signal of the recording paper. CONSTITUTION:The registration detection sensor 1 is provided reciprocally movably almost at right angles to the recording paper conveying direction of a paper feeding path A. Then sensor reciprocal driving means 41 - 44 move the registration detection sensor to the passing position at the side edge of the recording paper P according to the size signal of the recording paper P. Therefore, the side edge of the recording paper P passes the nearly constant detected position of the registration detection sensor 1 irrelevantly to the size of the recording paper. Consequently, the registration detection sensor 1 of the device is reducible in the width l of the detection part of its solid-state image pickup element 1A and the processing program for its driving and detection signals is simplified to reduce the cost of the device.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic registration adjustment device for paper feeding devices in digital copiers, laser printers, and the like.

(Prior Art) Paper feeding devices in copying machines, printers, etc., adjust the registration of recording paper that is conveyed toward an image forming device consisting of a photoreceptor, an exposure optical system, a developing device, etc. that forms an image of a JV document. Quality is a major factor in determining the appropriateness of the image forming position with respect to the recording paper.

Registration adjustment in conventional paper feeding devices involves aligning the side edge of the recording paper with the side edge of the image formed by the image forming device using a side fence (side plate) of the paper feeding cassette or paper feeding tray. , while adjusting the horizontal registration of the recording paper, the vertical registration of the recording paper is adjusted by abutting the leading edge of the recording paper against the nip of the registration roller disposed immediately before the image forming device. It was done by method.

However, with such a mechanical registration adjustment method, the recording paper may become skewed in the middle of the paper feeding path from the paper feeding position where the paper feeding cassette etc. is placed to the image forming device, or the registration rollers may become skewed. The leading edge of the recording paper is not properly bitten into the nip portion, resulting in a delay in the timing of feeding the leading edge of the recording paper to the image forming device, which may cause misalignment in the horizontal and vertical registrations of the recording paper.

In order to eliminate these drawbacks of mechanical resist adjustment devices, an automatic resist adjustment device based on a completely new idea was previously proposed. That is, in the conventional registration adjustment, the leading edge and side edges of the recording paper are registered in accordance with the image writing position of an image forming device, for example, the leading edge and side edges of a document image formed on a photoreceptor. On the other hand, this registration automatic adjustment device controls the image writing timing on the image forming device side in accordance with the leading edge position of the recording paper being conveyed through the paper feed path, and adjusts the leading edge and edge of the document image side. It is configured to register the formation position of the side edge. Specifically, a solid-state imaging device (CCD) and a light source (lamp) are placed on the sides of the paper feed path for recording paper conveyed toward the image forming apparatus, facing each other across the paper feed path. A registration detection sensor is provided, and this registration detection sensor detects the leading edge and side edges of the recording paper conveyed through the paper feeding path, and the image forming device operates based on the recording paper detection signal of this registration detection sensor. It is configured to control image writing timing. Namely, this resist! According to the I1g device, the leading edge position and side edge position of the recording paper transported along the paper feeding path are accurately determined for each recording paper by the solid-state image sensor of the registration detection sensor. Registration adjustment with the image can be automatically performed for each sheet of recording paper. Therefore.

With this registration adjustment device, even if the position of the recording paper is slightly shifted during the paper feeding path, it is possible to accurately register the recording paper and the image.

Note that the image writing timing of the above-mentioned image forming device is controlled by
Ordinary copiers and printers that use lenses and mirrors to expose original images tend to have somewhat complex configurations because they vary the lamp lighting timing and lens position. Digital copiers, laser printers, etc. that use beam-based optical writing units to form original images can electrically control the writing timing and position of original images, so there is no need to change the configuration. can be executed.

(Problem to be Solved by the Invention) By the way, the above-mentioned automatic registration adjustment device uses a solid-state image sensor (
A CCD) and a light g (lamp) are arranged opposite to each other across the recording paper feeding path, and a solid-state image sensor is used to capture the front and side edges of the recording paper conveyed along this paper feeding path. configured to detect. Therefore, in this automatic registration adjustment device, even if the sizes of the recordings conveyed through the paper feed path are different, such as when the recording paper is postcard size or A3 size, the leading edge and side edge of each recording paper is fixed. It is necessary to form it so that it can be detected by an image sensor.

For this reason, in the case of a one-sided reference paper feeding device in which the recording paper is conveyed using one side edge as the reference surface.

By placing a registration detection sensor at the edge of this reference plane, it is possible to detect the leading and side edge positions of recording paper of various sizes. In the case of a paper feed device, the registration detection sensor is moved from the side edge of the paper feed path to the center so that the solid-state image sensor and light source face the leading and side edge positions of recording paper of various sizes. It has to be formed into a very long length in the direction, and the drive and detection signal processing programs are complicated and the cost increases.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention disposes the registration detection sensor so as to be movable back and forth in a direction substantially perpendicular to the recording paper conveyance direction of the paper feed path. At the same time, the registration detection sensor is configured to be moved to a position where the side edge of the recording paper passes by a sensor reciprocating drive means driven based on a size signal of the recording paper.

(Function) According to the present invention, the registration detection sensor detects the size of the recording paper conveyed through the paper feeding path based on the size signal of the recording paper.

It is reciprocated in a direction substantially perpendicular to the recording paper transport direction of the paper feed path and faces the passing position of the side edge of the recording paper, so that the side edge of the recording paper can be registered regardless of its size. It passes through a substantially constant detection area of the detection sensor.

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

The registration detection sensor 1 of the automatic registration adjustment device according to the present invention is disposed on the side of the paper feed path A of the recording paper P, as shown in FIGS. 1 to 3.

The paper feed path A is formed by a pair of guide plates 2 and 3 that are arranged opposite to each other. The registration detection sensor 1 includes a solid-state image sensor (CCD) IA, which is disposed facing each other across the paper feed path A, and a light g (lamp) IB.
It is made up of. In addition, the resist detection sensor 1 is
It is disposed so as to be able to freely reciprocate in a direction (in the direction of arrow A) substantially perpendicular to the conveyance direction of recording paper P in paper feed path A (direction of arrow a in FIG. 2). This resist detection sensor 1
The reciprocating movement of is performed by the sensor reciprocating drive means 40.

The sensor reciprocating drive means 40 is the home position sensor 4
1. Mobile body 42. Drive shaft 43. and a drive motor 44 (see FIG. 1).

The home position sensor 41 is the registration detection sensor 1
, that is, the side plate 45 near the side edge of the recording paper P.
It is located in This home position sensor 41 detects a detection piece 41a formed at a portion facing the side plate 45 of the registration detection sensor 1, and outputs a sensor start signal.

The moving body 42 supports the registration detection sensor 1,
The guide stay 46 and the guide member 47 are supported in a reciprocating manner by a guide stay 46 and a guide member 47 arranged along the reciprocating direction of the registration detection sensor 1 (see FIG. 3). and a bracket 48 disposed opposite to this side plate 45.

The drive shaft 43 is rotatably disposed between the side plate 45 and the bracket 48 along the moving direction of the moving body 42 . A guide screw 43a is attached to the shaft portion of this drive shaft 43.
A half nut 42a formed on the movable body 42 meshes with this guide screw 43a (see FIG. 3).

The drive motor 44 has a drive gear 44b attached to its main shaft 44a, and is in mesh with the drive gear 44b.
#! via another drive gear 43b coaxially attached to #! The moving shaft 43 is rotated forward and backward (see Fig. 1).

The automatic registration adjustment device configured as described above operates as follows.

First, in FIG. 3, when the paper feed cassette 5 containing the recording paper P is set in the paper feed section of a laser printer or the like, a detection filler 5a for detecting the size of the recording paper P is inserted.
The size of the 29 paper P is detected by the paper size detection sensor 5b and the paper size detection sensor 5b.
When the paper size detection signal is given to a control device (not shown) (such as a microcomputer) built in a laser printer or the like, this control device outputs a reverse rotation command to the drive motor 44, and the drive motor 44 is rotated in the reverse direction. be rotated. As a result, the drive motor 44 is driven by the drive gear 44b,
The drive shaft 43 is reversely rotated via 43b.

By the reverse rotation of the drive shaft 43, the moving body 42 is moved in a direction approaching the side plate 45 via the guide screw 43a and half nut 42a. Due to this movement of the moving body 42, the registration detection sensor 1 reaches its starting position, and its detection piece 41a is detected at the home position 41. When the home position detection signal from the home position sensor 41 is given to the control device, a forward rotation command is output from the control device to the drive motor 44. The drive motor 44 that received the forward rotation command rotates the a-movement gear 4
4b and 43b, the drive shaft 43 is rotated forward by an amount commensurate with the size of the recording paper P. The amount of forward rotation of the drive shaft 43 is preset according to the size of the recording paper P to be fed. memorized RO
The program is programmed to read the forward rotation amount of the drive motor 44 suitable for the size of the recording paper P to be fed from the ROM and apply it to the drive motor 44 according to the paper size detection signal of the size detection sensor 5b. has been done.

That is, this program moves the registration detection sensor 1 to a predetermined position on the paper feeding path A, that is, to a position where the center of the solid-state image sensor IA faces the passing position of the side edge of the recording paper P being fed. It is set in advance so that it stops when Therefore, when the drive motor 44 is rotated forward according to the program, the drive shaft 43 is rotated forward by a predetermined amount, and the registration detection sensor 1 detects the size of the recording paper P to be fed. (see Fig. 2).

Then, when the print switch (not shown) is turned on with the movement of the registration detection sensor 1 completed,
The paper feed roller 6 rotates to feed the recording paper P from the paper cassette 5.
will be delivered. The recording paper P first hits the nip of the registration rollers 7 arranged at the entrance of the paper feed path A, and the skew is corrected.Next, when the registration rollers 7 rotate, the recording paper P is conveyed along paper feed path A. When the leading edge pb of the recording paper P (see FIG. 2) reaches the registration detection sensor 1, the optical path of the solid-state image sensor IA and the light glB is blocked by the recording paper P, and the leading edge pb of the recording paper P (see FIG. 2) is blocked by the recording paper P. At the same time as a detection signal is output, the position of the side edge Pa of this recording paper P is detected by the solid-state image sensor IA, and a paper side edge detection signal is output.

The control device receives the paper leading edge detection signal and the paper side edge detection signal from the registration detection sensor 1, controls the writing timing of the original image onto the photoreceptor 11 of the image forming device IO, and writes the original image onto the photoreceptor 11. As is well known, the image forming device 1O automatically adjusts the vertical and horizontal registrations between the original image to be written and the recording paper P. Charger 1
2. Laser writing unit 13. Developing unit 14. Transfer charger 152 Separate charger 16. and a cleaning unit 17. The recording paper P is transported toward the photoreceptor 11 by the transport roller 8, so that the original image written on the photoreceptor 11 is transferred in alignment (registered) with the leading edge pb and side edge Pa of the recording paper P. Thereafter, it is fixed by a fixing unit (not shown) and discharged.

As mentioned above, this resist automatic! l'! According to the device No. 1, a registration detection sensor 1 reciprocates in a direction b substantially perpendicular to a recording paper conveying direction a of a paper feeding route A based on a size signal of a recording paper P conveyed through a paper feeding route A. Since the side edge Pa of the recording paper P is moved and faces the passing position of the side edge Pa of the recording paper P, the side edge Pa of the recording paper P is a substantially constant detection area of the registration detection sensor 1 regardless of its size, that is,
It passes through approximately the center of the solid-state image sensor (COD) LA. Therefore, in the resist detection sensor 1 in this device, the detection portion 411Q of the solid-state image sensor IA can be made extremely small (see FIG. 1).

By the way, the guide plate 2 that forms the paper feed path A for the recording paper P
．． 3 on the side as shown in FIG.

Slits 2a and 3a are formed to allow the registration detection sensor 1 to move back and forth. This slit 2a,
It is desirable that l1lid of 3a be as small as possible in order to convey the recording paper P smoothly.
For example, as in the above embodiment, the solid-state image sensor IA and the light source I
If the solid-state image sensor IA and the light source IB are separated from each other without being integrated with the light source IB and configured to be moved back and forth individually, the light flux of the light MIB will pass through #d of the slits 2a and 3b. It can be formed to just the width.

(Effects of the Invention) According to the present invention, the resist detection sensor can be made extremely compact, and the drive and detection signal processing programs can be simplified to reduce the cost of the apparatus.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is a perspective view showing the operating mode of the embodiment, and FIG. 3 is a schematic diagram of a printer embodying the present invention. DESCRIPTION OF SYMBOLS 1... Registration detection sensor, LA... Solid-state image sensor, IB... Light source, 40... Sensor reciprocating drive means, 4
1... Home position sensor, 42... Moving object, 4
3... Drive shaft, 44... Drive motor, P... Recording paper, A... Paper feeding path. Agent Toru Kabayama

Claims (1)

[Claims] A resist detection sensor consisting of a solid-state image sensor and a light source is placed on the side of the paper feed path of the recording paper conveyed toward the image forming device that forms the image, and is placed opposite to each other across the paper feed path. In a paper feeding device that detects the leading edge and side edge of the recording paper conveyed through the paper feeding path and controls the image writing timing of the image forming device based on the recording paper detection signal, the recording paper of the paper feeding path The registration detection sensor is disposed so as to be reciprocally movable in a direction substantially perpendicular to the conveying direction, and a sensor reciprocating drive means driven based on a size signal of the recording paper allows the side edge of the recording paper to pass. An automatic registration adjustment device for a paper feeding device, characterized in that the registration detection sensor is moved to a certain position.