JPH058892A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent unfolding of the flap part of an envelope during conveyance of the envelope between a transfer part and a fixing part. CONSTITUTION:A press conveying means 14 to press both sides in a conveying direction of an envelope 2' for conveyance is located between a transfer/ separating charger 8 and a fixing device 9. The press conveying means 14 comprises upper and lower press rollers 15 and 16. By locating the proper number of the press conveying means 14 each comprising the upper and lower press rollers 15 and 16 between the transfer/separating charger 8 and the fixing device 9, the flap part thereof is prevented from opening even when the envelopes 2' are conveyed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention transfers a visible image formed on an image carrier to a transfer material fed to a transfer section, separates the transfer material from the image carrier and conveys it to a fixing section. The present invention relates to an image forming apparatus such as a laser printer and a copying machine.

[0002]

2. Description of the Related Art In an image forming apparatus such as a laser printer, an envelope is passed through in order to print an address on an image recording portion of the envelope. In this case, the envelope is provided with a flap portion, but at the time of printing, the flap was closed and paper was passed.

[0003]

However, even if the envelope is passed through the printer with the flap section closed, the envelope cannot be sandwiched and conveyed by the conveyance rollers or the like during the conveyance between the transfer section and the fixing section. Sometimes the parts were turned over and transported. Then, if the flap portion of the envelope enters the fixing device with the flap portion turned over, when the envelope passes through the fixing roller pair, the glue of the flap portion is melted by heat, and the glue adheres to the fixing roller pair, jams and then Problems such as soiling the transferred transfer material occurred.

The present invention solves the above-mentioned conventional problems,
An object of the present invention is to provide an image forming apparatus capable of preventing the flap portion of the envelope during conveyance between the transfer portion and the fixing portion from being turned over.

[0005]

The structure of the present invention for achieving the above object is as follows. (1) In the image forming apparatus, which transfers a visible image formed on an image carrier to a transfer material fed to a transfer section, separates the transfer material from the image carrier and conveys it to a fixing section, An image forming apparatus, comprising: a pressing / conveying unit that presses both sides of the transfer material in the conveyance direction with pressing members to convey the transfer material between the fixing unit and the fixing unit.

(2) In the image forming apparatus described in (1), the pressing member of the pressing conveying means presses the non-image area of the transfer material.

(3) In the image forming apparatus described in (1) 1, the pressing member of the pressing and conveying unit is moved in a direction orthogonal to the transfer material conveying direction, and the width of the envelope as the transfer material. An image forming apparatus comprising: a size detecting unit for detecting a size, and controlling a movement amount of the moving unit by a size signal of the size detecting unit.

(4) In the image forming apparatus described in the above (1), a releasing means for moving the pressing member of the pressing conveying means between an operating position for pressing the transfer material and a retracted position away from the transfer material, and An image forming apparatus comprising: a paper type detection unit for detecting the type of transfer material, and controlling the operation of the releasing unit by a signal from the paper type detection unit.

[0009]

According to the above construction (1), since the pressing and conveying means for pressing the both sides of the transfer material in the conveying direction with the pressing members to convey the transfer material is provided between the transfer portion and the fixing portion, the envelope passage You can prevent the flaps from flipping over when printing.

According to the above configuration (2), since the pressing and conveying means presses the non-image area of the envelope, the unfixed toner image transferred to the envelope can be conveyed without disturbing it.

According to the above configuration (3), the moving means for moving the pressing member of the pressing and conveying means in the direction orthogonal to the transfer material conveying direction is the size detecting means for detecting the width size of the envelope as the transfer material. Since the amount of movement of the moving means is controlled by the size signal, envelopes of various sizes can be conveyed without the flap portion flipping.

According to the above configuration (4), the releasing means for moving the pressing member of the pressing and conveying means between the operating position for pressing the transfer material and the retracted position away from the transfer material is used to detect the type of the transfer material. Since the operation of the releasing means is controlled by the signal of the paper type detecting means, the transfer material can be held and conveyed only when the transfer material is an envelope.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an overall schematic view of a laser printer showing an embodiment of the present invention. In FIG. 1, a recording paper 2 as a transfer material, which is conveyed from the paper feeding device 1 in the direction of arrow A, is conveyed by a registration roller pair 3 to a latent image carrier composed of a drum-shaped photoconductor 4 at a timing. . The photoconductor 4 is rotationally driven in the counterclockwise direction, the surface of the photoconductor 4 is charged by the charging charger 5, and the laser beam L from the laser optical system 6 is irradiated to form an electrostatic latent image on the photoconductor. This latent image is visualized by toner as it passes through the developing device 7, and this visible image is transferred / separated by a charger 8.
Thus, the recording paper 2 transferred to the photoconductor 4 is transferred, and the recording paper 2 in close contact with the photoconductor 4 is electrostatically separated. After that, a visible image is fixed on the recording paper 2 by the fixing device 9, and the recording paper 2 is conveyed in the direction of the arrow B and discharged to the paper discharge unit 11 on the printer body 10. On the other hand, after the visible image is transferred, the photoconductor 3 is destaticized by the destaticizing device 13 having an LED, the residual toner is removed by the cleaning device 12, and the removed toner is collected by the cleaning device 12.

This laser printer conveys an envelope 2'as a transfer material and can print a name and the like on the surface of the envelope 2 '. However, since the envelope 2'cannot be nipped and conveyed during the conveyance between the transfer section and the fixing section, the flap section is turned over and conveyed, and the adhesive adheres to the fixing roller pair, which causes a jam or a contamination of the transfer material to be conveyed next. As mentioned above, there are some problems such as the occurrence of problems.

The present invention takes the following measures to solve such a problem.

In FIGS. 1 and 2, between the transfer portion of the transfer / separation charger 8 and the fixing portion of the fixing device 9, there is provided a pressing and conveying means 14 for pressing and conveying both sides of the envelope 2'in the conveying direction. Has been. This presser feeding means 14
As shown in FIG. 3, is composed of an upper pressing roller 15 and a lower pressing roller 16. In this case, since the laser printer is of the upper conveyance and lower writing type, the upper pressing roller 15 is provided with a roller portion which is longer than the width of the envelope 2'on the roller shaft 15a. On the other hand, the lower pressing roller 16 is provided with short roller portions on the roller shaft 16a at positions corresponding to the non-image areas M on both sides of the image area L in the width direction of the envelope 2 '. Then, the vertical pressing roller 15,
By providing an appropriate number of pressing and conveying means 14 composed of 16 between the transfer / separation charger 8 and the fixing device 9, even if the envelope 2'is conveyed in the direction of arrow A, the flap portion thereof is opened and sent to the fixing device 9. Can be reliably prevented. Moreover, since the lower pressing roller 16 is in contact with the non-image area M of the envelope 2 ′, it is possible to prevent the unfixed toner image transferred to the envelope 2 ′ from being disturbed.

By the way, in the above embodiment, there is no problem when printing on envelopes 2'having a fixed size, but when printing envelopes 2'of various sizes, the non-image area M is printed.
Is also displaced, the lower presser roller 16 touches the image area L,
There is a possibility that the width of the envelope 2'is too small to be pressed by the lower presser roller 16 or the like. Further, the holding and conveying means 14 is necessary only when the envelope 2'is passed through the sheet, and it is better not to use it for the sheet-shaped recording sheet 2.

Therefore, in the present invention, as shown in FIG. 4, the lower presser roller 16 of the presser conveying means 14 is divided into right and left and each lower presser roller 16 is moved in the arrow C direction orthogonal to the conveying direction. Means (not shown) are provided. Further, the laser printer is provided with a size detecting means (not shown) for detecting the width size of the envelope 2 ', and as shown in FIG. 5, the movement amount of the moving means is changed by the envelope width detecting signal of the size detecting means. Have control.

According to this structure, envelopes of various sizes can be conveyed without the flaps turning up. A mechanism having a motor, a solenoid, or the like as a drive source can be used as the moving means.

Further, the roller shafts 15a, 16a of the upper pressing roller 15 and the lower pressing roller 16 of the pressing conveying means 14 are respectively bent and fixed to the rotating shafts 15b, 16b. Then, when the rotating shafts 15b and 16b are swung or rotated by a releasing means (not shown), the upper pressing roller 15 and the lower pressing roller 16 are moved between an operating position for pressing the transfer material and a retracted position away from the transfer material. It is configured to be able to move between. Further, the laser printer is provided with a paper type detecting means for detecting the type of the transfer material, that is, the type of the envelope 2'and the sheet-shaped recording paper 2. When the transfer material is the envelope 2 ', as shown in FIG. 6, the upper pressing roller 15 and the lower pressing roller 16 are moved to the operating position by the detection signal of the paper type detecting means, and the transfer material is a sheet-shaped recording paper. At the time of 2, the upper presser roller 15 and the lower presser roller 16 are controlled to move to the retracted position.

According to this structure, the upper pressing roller 15 and the lower pressing roller 16 of the pressing conveying means 14 are moved to the operating position when the transfer material is the envelope 2 ', and to the retracted position when the transfer material is the sheet-shaped recording paper 2. Therefore, only when the transfer material is an envelope, it is possible to carry it by pressing.

As the releasing means, a mechanism using a motor, a solenoid or the like as a drive source can be used. Further, by adding timing control to the control of FIGS. 5 and 6,
Even the same envelope can be passed from various directions. That is, although the envelope 2'is different in the size of the flap portion and the position of the flap portion, it is possible to pass the paper by adding the timing control to the control regardless of which envelope is changed in the direction of the flap portion during conveyance.

[0023]

According to the above construction, the present invention can prevent the flap portion from being turned up when the envelope is passed, and the pressing and conveying means presses the non-image area of the envelope, so that the unfixed toner image can be prevented from being disturbed. .

Furthermore, envelopes of various sizes can be conveyed without the flaps turning up, or can be held and conveyed only when the transfer material is an envelope.

[Brief description of drawings]

FIG. 1 is an overall schematic view of a laser printer to which the present invention is applied.

FIG. 2 is a plan view showing a main part of the image forming apparatus according to the present invention.

FIG. 3 is a perspective view showing an embodiment of an image forming apparatus according to the present invention.

FIG. 4 is a perspective view showing another embodiment of the image forming apparatus according to the present invention.

FIG. 5 is a block diagram showing the relationship between size detection and moving means.

FIG. 6 is a block diagram showing the relationship between paper type detection and moving means.

[Explanation of symbols]

4 photoconductor 8 Transfer / separation charger 9 Fixing device 14 Presser feeding means 15 Upper presser roller 16 Lower presser roller

Claims (4)

[Claims] 1. An image forming apparatus for transferring a visible image formed on an image carrier to a transfer material fed to a transfer part, and separating the transfer material from the image carrier to convey it to a fixing part. An image forming apparatus, comprising: between the transfer unit and the fixing unit, a pressing / conveying unit that presses both sides of the transfer material in the conveying direction with pressing members to convey the transfer material. 2. The image forming apparatus according to claim 1, wherein the pressing member of the pressing conveying unit presses the non-image area of the transfer material. 3. The image forming apparatus according to claim 1, wherein the pressing means of the pressing and conveying means is moved in a direction orthogonal to the transfer material conveying direction, and the width size of the envelope as the transfer material is detected. An image forming apparatus, comprising: a size detecting unit for controlling a moving amount of the moving unit according to a size signal of the size detecting unit. 4. The image forming apparatus according to claim 1, wherein the releasing member that moves the pressing member of the pressing conveying unit between an operating position for pressing the transfer material and a retracted position away from the transfer material, and the transfer material. And a paper type detecting means for detecting the type of the paper type, and the operation of the releasing means is controlled by a signal from the paper type detecting means.