JPH04277150A - Sheet transfer device - Google Patents

Abstract

PURPOSE:To remove noise due to loop drive and at the same time realize skew correction at which jam occurrence is extremely low regardless of a sheet basis weight, by providing a sheet guide member regulating the width direction of a transported sheet, providing a control means conducting movement control after a sheet width direction size. CONSTITUTION:Rollers R that act as transport means butting against a sheet P from the upper part of the sheet P, have a drive source B, and rotate in an arrow direction, and in addition, they have a movement means and are made to be capable of being moved in CC' directions. A guide member that is provided at both ends of a sheet P and regulates a sheet P width direction, consists of a guide plate G and a width adjusting plate HP and the stop position of the plate HP is made to be changeable in (a)(a') directions by means of a conversion means W. Also, a sheet width size housed in a housing cassette 151 is inputted beforehand at a control circuit C acting as a control means, and the stop position of the plate HP is controlled at a regular position through the means W.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to a conveying device for sheet materials (hereinafter referred to as "sheets") such as transfer paper and film used in image forming apparatuses such as copying machines and laser beam printers. The present invention relates to a sheet conveyance device equipped with a skew correction mechanism so that sheets can be conveyed in proper positions so that prevention, perforation, and lamination can be performed accurately.

0002

[Prior Art] Conventionally, the amount of skew of a sheet has been corrected by bringing the sheet into contact with a pair of rollers (registration rollers) that stop the sheet, creating a loop of a certain amount, and then driving the rollers again. was.

0003

[Problem to be Solved by the Invention] However, in such conventional technology, when the amount of skew is corrected by the pair of registration rollers as described above, the loop is suddenly canceled when the rollers start driving. The noise generated was unpleasant to the ears, and the noise was particularly noticeable in cardboard sheets having a large basis weight.

[0004] Furthermore, when the basis weight is extremely large or conversely when the basis weight is small (so-called stiff sheets), there are problems in that it is difficult to create loops and jams are likely to occur.

The present invention has been made to solve the problems of the prior art described above, and its purpose is to provide a sheet guide member that regulates the width direction of a sheet to be conveyed, By providing a control means that controls the movement according to the width direction size of the sheet to be moved,
It is an object of the present invention to provide a sheet conveying device capable of always accurately conveying sheets by correcting skew of conveyed sheets.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a conveying means for conveying a sheet in a predetermined direction, and a conveying means for conveying the sheet in a predetermined direction, and a conveying means for guiding the sheet, and a conveying means for guiding the sheet so as to sandwich the sheet. a pair of sheet guide members disposed on the side, at least one of which is movable in the width direction of the sheet; a converting means for switching the stop position of the sheet guide member; and the converting means into which the widthwise size of the sheet to be conveyed is input in advance. and control means for controlling the stop position of the sheet guide member by issuing a signal to the sheet guide member.

[0007]

[Function] Even if the sheet is conveyed obliquely, the sheet guide member regulates the width direction of the sheet, so the oblique conveyance is corrected and the sheet is always conveyed accurately.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on the illustrated embodiments. FIG. 1 shows an overview of a sheet conveying device according to the present invention. In the same figure, (a) shows a plan view, and (b) shows a side view of the same. In the figure, P is a sheet conveyed in the direction of arrow D. A roller R serving as a conveyance means contacts the sheet P from above, and has a drive source B to rotate in the direction of the arrow. Furthermore, this roller R has a known moving means as shown in FIG.
It is movable in the C' direction.

[0009] A guide plate G and a width adjusting plate HP are disposed at both ends of the sheet P so as to regulate the width direction of the sheet P. These form a pair, and the width adjustment plate HP is converted to a by the conversion means W.
The stop position can be changed in the a' direction.

Furthermore, C shown in FIG. 1(a) is a control circuit as a control means, in which the width size of the sheet stored in the sheet storage cassette 151 is inputted in advance, and the width adjustment plate HP is inputted via the conversion means W. The stop position of the machine is controlled to the normal position. In addition, in this embodiment, when moving the width-adjusting plate HP, the control circuit C uses the drive source B.
The rotation of the roller R is stopped and the roller R is also controlled to be moved in the C' direction. The control contents of this control circuit C are performed according to the flowchart shown in FIG.

In the figure, S indicates a sensor that detects the passage of the sheet, and 159 indicates a conveyance roller that further conveys the sheet.

Further, in the above configuration, only the width adjustment plate HP, which is one of the sheet guide members, is movable, but it is of course possible to configure only the guide plate G or both of them to be movable.

The sheet conveyance device of the present invention has been described in detail above, and the operation will also be described with reference to FIG. 4 when the device of this embodiment is applied as a sheet supply section of an image forming apparatus.

First, the image forming apparatus will be briefly described.In the main body 100, 101 is an original table glass on which an original is placed, 103 is an illumination lamp (exposure lamp) that illuminates the original, 104 is a pressure plate 105 that presses the original, 107,
109 is a scanning reflecting mirror (scanning mirror) that changes the optical path of the reflected light from the original, 111 is a lens having focusing and magnification functions, and 113 is a fourth reflecting mirror (scanning mirror) that changes the optical path. be. 115 is an optical system motor that drives the optical system, and 110, 117, and 121 are sensors, respectively. 131 is a photosensitive drum, 133 is a main motor that drives the photosensitive drum 131, 135 is a high pressure unit, 137 is a blank exposure unit, 139 is a developing device,
141 is a transfer charger, 143 is a separation charger, and 14
5 is a cleaning device.

A is a sheet feeding section to which the sheet conveying device of the present invention is applied. In the figure, 151 is a cassette storing sheets, R is a supply roller as a conveying means, and 1
59 is a conveyance roller. Further, 161 is a conveyor belt that conveys the sheet on which an image has been recorded to the fixing side, and 163 is a fixing device that fixes the conveyed sheet by heat fixing. 1
65 is a discharge roller.

The surface of the photosensitive drum 131 described above is made of a seamless photosensitive member using a photoconductor and an electric conductor. The motor 133 starts rotating in the direction of the arrow in the figure. Next, when the predetermined rotational control and potential control processing (preprocessing) of the drum 131 are completed, the original placed on the original platen glass 101 is illuminated by the illumination lamp 103 that is integrated with the first scanning mirror 105. The reflected light from the original is reflected by the first scanning mirror 105,
The drum 131 passes through the second scanning mirror 107, the third scanning mirror 109, the lens 111 and the fourth scanning mirror 113.
image on top.

The drum 131 is corona charged by a high pressure unit 135. After that, the image (original image) irradiated by the illumination lamp 103 is exposed to slit light, and the well-known N
An electrostatic image is formed on the drum 131 using the P method.

Next, the electrostatic latent image on the photosensitive drum 131 is
It is developed by the developing roller 140 of the developing device 139 and visualized as a toner image, and the toner image is transferred to the transfer charger 14.
1 onto the sheet.

Now, to explain the supply unit A, based on the sheet size information from the cassette 151 (that is, the size of the sheet P) installed in the image forming apparatus, the control circuit C adjusts the width adjustment plate according to the size width of the sheet P. The HP is moved by a certain amount in a direction (a→a') perpendicular to the conveying direction D of the sheet P. The sheet P in the cassette 151 is started to be supplied by the supply roller R driven by the drive source B. When the supply roller R has supplied a certain amount of the sheet P, it is stopped by the control means C and lifted by the driving source B in the vertical direction C→C'. Width adjustment plate HP
is a fixed amount (width of sheet P - guide plate G) by control circuit C.
(the amount that corresponds to the distance between the width adjusting plate HP) and the width adjustment plate HP). In other words, even if the sheet P is conveyed obliquely as shown in FIG.
The skew is corrected by being suppressed by (see FIG. 2(b)).

After the skew correction, the supply roller R is lowered by the drive source B from the control circuit C and driven again. sheet P
The leading edge of the latent image and the leading edge of the sheet are accurately aligned by controlling the driving unit B based on a signal from a sheet edge detection sensor S placed in the conveying direction of the sheet.

Thereafter, the sheet passes between the transfer charger 141 and the drum 131, so that the toner image on the drum 131 is transferred onto the sheet. After the transfer, the sheet is separated from the drum 131 by a separation charger 143, guided to a fixing device 163 by a conveyor belt 161, fixed by pressure and heat, and then discharged from the main body 100 by a discharge roller 165.

[0022]

Effects of the Invention The present invention has the structure and operation described above, and is provided with a means for conveying a sheet and a guide member for correcting the skew of the sheet, and is moved by a control means, unlike the conventional method. A sheet conveying device that eliminates the need to create sheet loops to correct skew feeding, eliminates noise caused by loop drive, and at the same time is capable of skew correction with extremely low occurrence of jams regardless of the basis weight of the sheet. can be provided as.

[Brief explanation of the drawing]

FIG. 1 shows an outline of a sheet conveying device according to an embodiment of the present invention, in which (a) is a plan view and (b) is a side view.

FIGS. 2(a) and 2(b) are diagrams showing how skew correction is performed.

FIG. 3 is a flowchart showing the details of control by the control circuit.

FIG. 4 is a diagram showing an example in which the sheet conveying device of the present invention is applied to an image forming apparatus.

[Explanation of symbols]

R Conveying means (roller) G, HP Sheet guide member (G guide plate, HP
(width shifting plate) C Control means (control circuit) D Conveying direction P Sheet

Claims (1)

[Claims] 1. A conveyance means for conveying a sheet in a predetermined direction, and a pair of conveyance means disposed on both sides of the sheet so as to sandwich the sheet in order to guide the sheet, at least one of which is movable in the width direction of the sheet. a sheet guide member, a conversion means for switching the stop position of the sheet guide member, and a control means that receives a width direction size of the sheet to be conveyed in advance and sends a signal to the conversion means to control the stop position of the sheet guide member. A sheet conveying device comprising: