JPH0627955B2 - Sheet material feeder - Google Patents

Description

The present invention relates to a paper feed failure detection device for an image support material of an image forming apparatus such as an electronic copying machine, which is provided in, for example, a manual paper feed unit.

In an electronic copying apparatus capable of copying using sheet materials of different sizes, it is extremely important to always hold the position of the sheet material constant and guide it to the transfer portion. That is, if the sheet material is supplied to the transfer portion while the position of the sheet material is deviated, the transferred image may be deviated and may not be detachable when the sheet is detached from the photosensitive drum.
This tendency is more often in the case where the sheet material is fed from the manual feeding section than in the case where the sheet material of a predetermined size is automatically fed from the sheet feeding device.

The reason for this is that in the case of automatically feeding the sheet, the sheet material is usually placed in a sheet feeding cassette or the like. That is, it is correctly installed at the determined position. On the other hand, in the case of manual feeding, there is a high possibility that the user will arbitrarily set the sheet material.

In order to prevent such a defect, among the conventional apparatuses, a sheet material detecting means is provided at a position corresponding to the end portion of the sheet material in the direction orthogonal to the sheet material conveying direction during the paper feeding process. (Japanese Utility Model Publication No. 57-19711).

The purpose of the above apparatus is to detect the jammed sheet material and stop the operation of the apparatus such as the electronic copying apparatus. However, what is most desirable for the device is to prevent jamming.

The present invention reliably feeds and conveys the sheet material even if the set of the sheet material is somewhat uncertain in the case of manual sheet feeding, etc. It is an object of the present invention to provide a sheet feeding device that stops a copying operation and prevents an accident such as a separation failure.

The present invention is a separation means for separating the sheet material from the image carrier,
A sheet material guide that regulates the position of the sheet material along the sheet material transportation direction upstream of the sheet material transportation path from the separating means; and a skew feeding means that transports the sheet material in a direction along the sheet material guide. A sheet material feeding device for an image forming apparatus, the sheet material detecting means being disposed between the oblique feeding means and the separating means and arranged on a line along the sheet material conveying direction passing through the separating means. A sheet material feeding device of the image forming apparatus, the control means controlling the image forming apparatus according to the signal of the detecting means.

Embodiments of the present invention will be described in detail below with reference to the drawings.

The embodiment shows a paper feeding device of an electronic copying machine as shown in FIG. A case where paper is used as the sheet material will be described.

FIG. 1 is a perspective view mainly showing a transfer position and a separating mechanism. A corona discharger which is a latent image forming means, an exposure optical system, and a developing device which is a means for developing the formed latent image are provided around the photosensitive drum 1 having a photosensitive layer around the image bearing member. (Not shown) are sequentially arranged at predetermined positions along the rotational direction of the arrow of the photosensitive drum 1.

A skew feeding unit 4 is provided on a transfer path 3 for the transfer sheet 2 that has passed a sheet feeding roller (not shown).

As shown in FIG. 2, the skew feeding means 4 is provided with a transfer path 3 for the transfer paper 2.
The drive roller 5 is provided through the hole 6 for the drive roller 5 so that the uppermost surface of the drive roller 5 is slightly seen, and is rotated in the direction of the arrow by the drive means (not shown). At the center of the uppermost part of the drive roller 5, a driven ball 7 that is pressed against the drive roller 5 by its own weight and is rotated by the drive roller 5 is held by a fixed housing 8. The traveling direction of the upper surface of the drive roller 5 is a direction B which is slightly leftward from the normal moving direction A of the transfer paper 2.

A paper guide 9 is provided on the left side of the transfer path 3 for the transfer paper 2,
The front end of the paper guide 9 and the feed roller pair 10 provided next
A paper detection switch 11 having a contact member seen from the lower surface to the upper surface of the conveyance path is fixed at a position within the separation width b from the left end of the conveyance path 3 between the above and.

Separation means 12 is provided in contact with the left end of the photosensitive drum 1. The separating means 12 has a separation guide 13 made of, for example, a thin metal or polyester film, one end of which is fixed above the transport path 3 and extends in the moving direction of the transfer paper.
Of the tension spring 15 is fixed to the lower end of the tension spring 15, the upper end of which is fixed. The separating means 12 is not limited to the above,
You may use a separating claw or the like.

The distance between the right edge of the separation guide 12 and the paper guide 9 is the above-described separation width b.

Further, a corona discharger 16 is provided downstream of the developing device in the rotation direction of the photosensitive drum 1 and between the feed roller pair 10 and the separating means 12 and close to the photosensitive drum 1.

When the copying operation is started, the photosensitive drum 1 rotates in the direction of the arrow, and the latent image formed by the exposure optical system is developed by the developing device.

On the other hand, the transfer paper 2 fed by the paper feed roller moves in the direction of the arrow A in the conveyance path 3, and if the transfer paper 2 does not move along the paper guide 9, the drive roller 5 and the driven ball 7 are moved. During the movement, the drive roller 5 and the driven ball 7 move to the left and move forward (that is, in the direction of arrow B), and then move along the paper guide 9.

Next, if the paper detection switch 11 comes into contact with the transfer paper 2, the paper detection switch 11 continues the copying operation by a control means (not shown), but if the transfer paper 2 does not come into contact with the paper detection switch 11, control is performed. Means stops the electronic copying machine.

When the transfer paper 2 comes into contact with the paper detection switch 11 and the copying operation is continued, the front end of the transfer paper 2 reaches the feed roller pair 10, the rotating photosensitive drum 1 and the developing position are synchronized and further moved. Then, the photosensitive drum 1 by the corona discharger 16
An electric charge having a polarity opposite to that of the electric charge is applied to the developed developer particles, and the developer particles are transferred to the transfer paper 3 side,
After the transfer process is completed, the transfer paper 2 that is in close contact with the photosensitive drum 1 is separated from the photosensitive drum 1 by the separating means 12, and reaches the fixing device (not shown).

On the other hand, the developer remaining on the photosensitive drum 1 during the transfer is removed by the cleaning means.

The case where the sheet material is manually fed in the electronic copying apparatus has been described above, but a good result is naturally obtained even in the electronic copying apparatus in which the sheet feeding apparatus automatically feeds the sheet material.

As described above, the present invention provides a separating means for separating the sheet material from the image carrier, and a sheet material guide for regulating the position of the sheet material along the sheet material conveying direction upstream of the separating means in the sheet material conveying path. A sheet material feeding device for an image forming apparatus, the sheet material feeding device conveying the sheet material along the sheet material guide in a direction along the sheet material guide, the sheet material feeding device being located between the oblique feeding means and the separating means. Since there is a sheet material detecting means arranged on a line passing through the separating means along the sheet material conveying direction and a control means for controlling the image forming apparatus by the signal of the detecting means, the manual feeding guide is somewhat uncertain. Even so, even if the sheet is reliably corrected and the manual sheet feeding guide is so bad that the sheet cannot be straightened to the proper sheet material conveying path and the sheet material is not guided to the position where it passes through the separating means. , Image forming device operation To prevent the occurrence of the stop jam in advance. Further, even if the sheet cannot be corrected, the operation of the image forming apparatus is stopped, so that the transferred image is prevented from being displaced with respect to the sheet material.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG. 2 is an enlarged sectional side view showing a skew feeding means. 1 ... Photosensitive drum, 2 ... Transfer paper, 3 ... Transport path, 4 ...
... oblique feeding means, 5 ... drive roller, 6 ... hole, 7 ... driven ball, 9 ... paper guide, 10 ... feed roller pair, 11
…… Paper detection switch, 12 …… Separation means.

Claims (1)

[Claims] 1. A separating means for separating a sheet material from an image carrier, a sheet material guide for regulating the position of the sheet material along the sheet material conveying direction upstream of the separating means in the sheet material conveying path, A sheet material feeding device of an image forming apparatus, comprising: a skew feeding unit that conveys a sheet material in a direction along a sheet material guide, wherein the separating unit is provided between the skew feeding unit and the separating unit. A sheet material feeding device for an image forming apparatus, comprising: a sheet material detecting means arranged on a line along the sheet material conveying direction; and a control means for controlling the image forming apparatus according to a signal from the detecting means.