JPS6311961A - Electrostatic copying machine - Google Patents

Abstract

PURPOSE:To prevent occurrence of a disturbance in an electrostatic latent image and/or developed picture in the copying process after a paper jam, by activating a main electric motor coupled with a photosensitive body and moving the photosensitive body when the stopping operation of an emergency stopping means is cancelled. CONSTITUTION:If a manual operation cancelling switch 362 is operated after removing jammed copying paper when the copying process of an electrostatic copying machine is emergency-stopped due to a paper jam, a rotating drum 12 is rotated in excess of a prescribed quantity by the action of a preparatory driving means 364. Then a developing device 24 which also functions as a cleaning means, destaticizing corona discharger 28, and destaticizing lamp 30 are actuated while the rotating drum 12 is rotated. In such a way, residual electric charges and/or toner particles remaining on the photosensitive body due to the previous copying process intermitted by the occurrence of a paper jam are sufficiently removed before starting the next copying process.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to an electrostatic copying machine, and more particularly to a type of electrostatic copying machine that transfers a developed image (toner image) or an electrostatic latent image formed on a photoreceptor onto copy paper. Regarding electronic copying machines.

<Prior Art> In recent years, electrostatic copying machines have been known to form an electrostatic latent image corresponding to the image of a document to be copied on a photoreceptor, and then apply toner particles to this electrostatic latent image to form a developed image. 2. Description of the Related Art Electrostatic copying machines of a developing image transfer type that perform a copying process of developing and then transferring the developed image on a photoreceptor to copy paper are widely used in practice. In current image transfer type electrostatic copying machines such as A photoreceptor is provided that is moved through a shaped travel path (ie, a circular or other suitable shaped endless travel path defined by the surface of a rotating drum or endless belt-like member). Then, along the moving path of the photoreceptor, sequentially, as viewed in the direction of movement of the photoreceptor,
An electrostatic latent image forming area, a developing area, and a transfer area are located. In the electrostatic latent image formation area, a charging corona discharger generally applies a corona discharge onto the photoreceptor, thus charging the photoreceptor to a particular polarity. The image of the document to be copied placed on the transparent plate of the document placement mechanism is projected onto the photoreceptor by the action of the optical system, and the photoreceptor is thus exposed to light and the charge on the photoreceptor is selectively erased. An electrostatic latent image corresponding to the image of the original to be copied is formed. In the development zone, toner particles are attached to the electrostatic latent image on the photoreceptor according to its charge by the action of the development device, and thus the electrostatic latent image becomes the developed image (
toner image). Further, in the transfer area, the current image on the photoreceptor is transferred onto the copy paper that is conveyed through the transfer area, and thus a current image corresponding to the image of the original is generated on the copy paper.

Charges and toner particles remaining on the photoconductor after the transfer of the developed image in the transfer zone are removed from the photoconductor after the transfer of the developed image in the transfer zone in order to avoid adversely affecting the subsequent copying process. be done. Removal of residual charges is accomplished by exposing the entire surface of the photoreceptor to light using a static elimination lamp and/or by applying corona discharge onto the photoreceptor using a static elimination corona discharger. On the other hand, residual toner is removed by applying a cleaning means such as a cleaning blade or a magnetic brush mechanism to the surface of the photoreceptor. When the above-mentioned developing device is constituted by a magnetic brush mechanism, the developing device can function not only as a developing means but also as a cleaning means.

In addition, an electrostatic copying machine of an electrostatic latent image transfer type rather than a developed image transfer type, in other words, an electrostatic latent image formed on a photoreceptor is directly transferred to copy paper without development, and then the electrostatic latent image is transferred onto copy paper. Toner particles are applied to the electrostatic latent image transferred to the image to develop it,
Electrostatic copying machines have also been proposed that differ from the above-mentioned current image transfer type electrostatic copying machines in that they generate a current image corresponding to a document on copy paper.

As is well known to those skilled in the art, in the electrostatic copying machine of the above-mentioned image transfer type or electrostatic latent image transfer type, generally, when a so-called paper jam occurs in the copy paper conveyance path, a paper jam detection means for detecting the paper jam and generating a paper jam signal; an emergency stop means for stopping the copying process by the electrostatic copying machine in response to the paper jam signal; A manual release switch is also provided which can be manually operated after the paper has been removed to deactivate the emergency stop means and resume performance of the copying process.

<Problems with the Prior Art> However, in conventional electrostatic copying machines, when the manual operation release switch is operated after removing the jammed copy paper, the normal copying process is resumed without any special action being performed. For example, when at least a part of the current image remains on the photoreceptor without being transferred onto the copy paper, the following problems occur. Even if a copy paper jam occurs, the copying process of the electrostatic copying machine is immediately stopped by the action of the detection means and emergency stop means, so that at least a portion of the current image remains on the photoreceptor. The copying process may be aborted in this state. In such a case, if you directly restart the copying process after removing the jammed copy paper and operating the manual operation release switch, the jammed copy paper may remain on the photoreceptor as it is easily understood. The next copying process is carried out without sufficient static neutralization and/or cleaning action being performed on the current image in the previous copying process (i.e., the copying process was aborted due to the occurrence of a paper jam), and therefore the previous copying process is Residual charge and/or residual toner particles from one copying step disturb the electrostatic latent image and/or developed image formed by the next copying step.

<Problems to be Solved by the Invention> The problems to be solved by the present invention are to prevent electrostatic latent images and/or developed images from forming in the copying process after removing the jammed copy paper, even in a pigeonhole where a copy paper jam occurs at any point in time. An object of the present invention is to improve an electrostatic copying machine so that disturbances are reliably prevented from occurring.

<Solution Means of the Invention> According to the present invention, when the jammed copy paper is removed and the manual operation release switch is further operated to release the stopping action of the emergency stop means, the main unit drivingly connected to the photoreceptor is released. A preparatory drive means is provided for energizing the electric motor to move the photoreceptor.

That is, according to the present invention, a having a having, a photoreceptor disposed within the housing so as to be movable through an endless movement path defined within the housing, and a photoreceptor positioned along the movement path of the photoreceptor. a charging corona discharger for applying corona discharge to the photoreceptor in the electrostatic latent image forming area; an optical system for exposing the photoreceptor to light in the electrostatic latent image forming area; a copy paper conveyance system for conveying the copy paper through a predetermined conveyance path passing through a transfer area located along the movement path of the photoreceptor downstream of the electrostatic latent image forming area as viewed in the movement direction;
Paper jam detection means for detecting a copy paper jam when it occurs in the copy paper conveyance path and generating a paper jam signal; and emergency stop means for stopping execution of the copying process in response to the paper jam signal. and a manual operation release switch for releasing the stop action of the emergency stop means; when the manual operation release switch is operated to release the stop action of the emergency stop means, the photosensitive An electrostatographic copying machine is provided which also includes a preparatory drive means for energizing a main electric motor drivingly connected to the body to move the photoreceptor through the endless travel path.

<Specific Examples of the Invention> Hereinafter, an image transfer type electrostatic copying machine, which is a specific example of an electrostatic copying machine improved according to the present invention, will be described in detail with reference to the accompanying drawings.

First, with reference to FIGS. 1 and 2, the overall structure of the illustrated electrostatic copying machine will be outlined.

The illustrated electrostatic copying machine has a generally rectangular parallelepiped-shaped housing, which is generally designated by the number 2. On the top surface of this housing 2,
A document placement mechanism 4 for holding a document to be copied is provided. The document placement mechanism 4 includes a support frame 6 mounted movably in a predetermined direction (i.e., left and right in FIG. 2) using an appropriate method, and a document fixed to the support frame 6 on which the document to be copied is placed. A transparent plate 8 (FIG. 2) and one edge (the upper edge in FIG. 1) are rotatably connected to the support frame 6, and a document placed on the transparent plate 8 and its upper surface is The part that covers i! ! (the position shown in FIGS. 1 and 2) and an open position that exposes the transparent plate 8 and the original placed on the upper surface thereof. There is. When the electrostatic copying machine is not in operation, the document mounting device 1ffIt4 is located at the stop position shown by the solid line in FIGS. When performing the scanning movement, it moves from the above-mentioned stop position 1 to the right in FIG. 2 to the scanning movement start position shown by the two-dot chain line 4A in FIG. 2,
Next, from this scanning movement start position, the scanning movement is carried out leftward in FIG. 2 to the scanning movement end position shown by the two-dot chain a4B in FIG. 2, and then to the right in FIG.
The upper front of the housing 2, which is preferably of a type that can be moved back to , is equipped with operating elements such as a main switch, a copy number setting knob, an exposure intensity adjustment knob, etc., which are well known in itself, and an indicator lamp. Display elements are arranged.

As briefly illustrated in FIG. 2, a cylindrical rotating drum 12 is rotatably mounted in the housing 2, and a photoreceptor is disposed on at least a portion of the circumferential surface of the rotating drum 12. Thus, instead of a zero rotation drum 12 in which rotation of the rotating drum 12 causes the photoreceptor to move through a circular endless travel path defined by the circumferential surface of the rotating drum 12, the photoreceptor may be moved in the form of an endless belt, as is well known to those skilled in the art. It is also possible to install the member in the housing 2 and arrange a photoreceptor on at least a portion of the surface of the endless belt-like member. In this case, the photoreceptor is moved through an endless movement path defined by the surface of the endless belt-like member by movement of the endless belt-like member.

Rotating drum 12 rotated in the direction shown by arrow 14
, and thus along the path of movement of the photoreceptor disposed on the rotating drum 12 , the electrostatic latent image forming area 16 , the developing area 18 and the transfer area are sequentially arranged as viewed in the direction of movement of the photoreceptor. Area 2
0 is placed.

A charging corona discharger 22 is disposed in the electrostatic latent image forming area 16 for applying corona discharge to the surface of the photoreceptor to charge it to a specific polarity.

The developing area 18 functions as a developing means for applying toner particles to the electrostatic latent image on the photoreceptor to develop it, and in the illustrated example, the developed image on the photoreceptor is transferred onto copy paper in the transfer area 20. A developing device fi24 is provided which also functions as a cleaning means for removing residual toner particles remaining on the photoreceptor after being transferred. A transfer corona discharger 26 is disposed in the transfer area 20 for applying corona discharge to the back surface of the copy paper when transferring the current image on the photoreceptor onto the copy paper.

Furthermore, as seen in the rotational direction of the rotary drum 12 shown by the arrow 14, and therefore in the moving direction of the photoreceptor, there is a transfer area downstream of the transfer area 20 and upstream of the electrostatic latent image forming area 16. A static elimination corona discharger 28 and a static elimination lamp 30 are used to remove or eliminate residual charges remaining on the photoconductor after the current image on the photoconductor is transferred onto copy paper at step 20.
is installed. The static elimination corona discharger 28 applies corona discharge to the photoreceptor for static elimination, and the static elimination lamp 30 exposes the entire surface of the photoreceptor.

In the housing 2, above the rotating drum 12, an optical system 32 is disposed for projecting an image of the original placed on the transparent plate 8 of the original placing mechanism 4 onto the photoreceptor. The optical system 32 includes an original irradiation lamp 36 that irradiates the original through an exposure opening 34 formed on the upper surface of the housing 2, a first reflecting mirror 38 that projects reflected light from the original onto a photoreceptor, and an in-mirror. It has a lens 40, a second reflecting mirror 42, and a third reflecting mirror 44. The optical system 32 is mounted on the transparent plate 8 of the document placement mechanism 4, as shown by the dashed arrow in FIG. 5! The image of the overturned original is transferred to the electrostatic latent image forming area 16.
The light is projected onto the photoreceptor at a position immediately downstream of the charging corona discharger 22 when viewed in the rotational direction of the rotating drum 12 therein. In the illustrated example, the image of the document is scanned and exposed on the photoreceptor by scanningly moving the document placement mechanism 4. However, instead of this, at least a portion of the optical system 32 may be scanningly moved. By doing so, it is also possible to scan and expose the image of the original onto the photoreceptor.

The illustrated electrostatic copying machine is further provided with a copy paper transport system generally indicated by the numeral 46. The copy paper transport system 46 includes a copy paper cassette 50 whose tip end is inserted into a cassette receiver 48 in the housing 2 through an insertion opening formed in the right end wall of the housing 2, and a copy paper cassette 50 formed on the top surface of the copy paper cassette 50. copy paper cassette 50 through the opening
Copying paper that feeds the sheet-like copying paper one by one from the copying paper cassette 50 by being engaged with the uppermost one of a plurality of sheet-like copying papers stored in a stacked state in the copy paper cassette 50 and being rotationally driven. A pair of conveying rollers 55 for conveying the sheet-like copy paper sent out by a mechanism between the feeding roller 52 and the transfer area 20, and a rotating drum 1 in the transfer area 20.
2 includes a separating roller 56 for separating the copy paper that is in close contact with the surface of the photoreceptor 2 from the photoreceptor and transporting it out of the transfer area 20. The copy paper carried out from the transfer area 20 is passed through a housing, through a fixing mechanism generally designated by numeral 58, for fixing the current image transferred from the photoreceptor onto the copy paper in the transfer area 20 onto the copy paper. The liquid is discharged into the receiving tray 60 through a discharge opening formed in the left end wall of No. 2 . Note that although the copy paper transport system 46 in the illustrated specific example is equipped with a copy paper feed mechanism 54 that utilizes a copy paper cassette 50, it is noted that such a copy paper feeder [54] Alternatively, in addition to this, a copy paper feeding mechanism of a type that unwinds a roll of copy paper, cuts it to a required length, and sends it out can also be installed in the copy paper transport system 46.

To summarize the operation of the electrostatic copying machine as described above, first, while the rotating drum 12 is rotated in the direction shown by the arrow 14, static electricity is applied to the surface of the photoreceptor in the electrostatic latent image forming area 16. A latent image is formed. The formation of an electrostatic latent image is
The charging corona discharger 22 applies corona discharge to the photoreceptor to charge it to a specific polarity, and then the image of the document placed on the transparent plate 8 is projected onto the photoreceptor by the optical system 32. It is carried out by When the image of the original is projected onto the photoreceptor by the optical system 32, as described above, the original W@ellipse 4 is moved two points to the left from the scanning movement start position shown by the two-dot chain line 4A in FIG. The scanning movement is made to the scanning movement end position shown by the chain line 4B. Next, development area 1
At 8, toner particles are applied to the electrostatic latent image on the photoreceptor by the action of developer device 24, thus developing the electrostatic latent image on the photoreceptor. On the other hand, the copy paper transport system 46 transports the copy paper to the transfer area 20 in synchronization with the rotation of the rotary drum 12, and the current image on the photoreceptor is transferred onto the copy paper in the transfer area 20. The copy paper to which the current image has been transferred is fixed to the fixing mechanism a 58.
After receiving the fixing action of Even after the current image on the photoreceptor is transferred onto the copy paper, the rotating drum 12 continues to rotate, preferably at least one rotation, particularly preferably two or more times. The residual charge on the photoreceptor is removed or eliminated by the actions of the static elimination corona discharger 28 and the static elimination lamp 30, and the developing device 24 also functions as a cleaning means to remove the residual toner on the photoreceptor.

The above-described configuration and operation of the illustrated electrostatic copying machine are merely an example of an electrostatic copying machine to which the present invention is applied, and therefore, their details will be described in the patent application, which is the so-called original application of the present application. Application No. 55-49497 (Japanese Unexamined Patent Publication No. 56-1461)
No. 55), and will be omitted in this specification.

- Well, 2.

As is well known to those skilled in the art, electrostatic copying machines generally have a paper jam detection system that detects a so-called paper jam in the copy paper transport path and generates a paper jam signal. and emergency stop means for stopping the electrostatic copying machine from performing the copying process in response to the paper jam signal;
Further, a manual operation release switch is provided which is manually operated after removing the jammed copy paper to cancel the action of the emergency stop means and restart the copying process.

The illustrated electrostatic copying machine also includes a paper jam detection means, an emergency stop means (these means are not shown), and a manual operation release switch 3, whose configurations may be well-known.
62 (Fig. 3) is equipped.

As mentioned above, in conventional electrostatic copying machines, when the manual operation release switch is operated after removing the jammed copy paper, the normal copying process is resumed without any special action being performed. Since the system is configured to restart, the following problem occurs. For example, even if a copy paper jam occurs when at least a part of the current image on the photoreceptor still remains without being transferred onto the copy paper, the detection means and the emergency stop means Due to this action, the copying process of the electrostatic copying machine is immediately stopped, and therefore, the copying process may be terminated with at least a portion of the current image remaining on the photoreceptor. In such a case, if you directly restart the copying process after removing the jammed copy paper and operating the manual operation release switch, the jammed copy paper may remain on the photoreceptor as it is easily understood. The next copying process is carried out without sufficient static neutralization and/or cleaning action being performed on the current image in the previous copying process (i.e., the copying process was aborted due to the occurrence of a paper jam), and therefore the previous copying process is Residual charge and/or residual toner particles from one copying step disturb the electrostatic latent image and/or developed image formed by the next copying step.

In order to solve the above-mentioned problems in conventional electrostatic copying machines, the present invention removes the jammed copy paper and further releases the emergency by operating the manual release switch 362 (FIG. 3). Preparatory drive means are provided for energizing a main electric motor (not shown) drivingly connected to the photoreceptor to move the photoreceptor upon release of the stop action of the stop means (not shown). This is very important.

Referring to FIG. 3, in the illustrated example, the preparation drive means 364 is configured to operate the manual operation release switch 3.
When 62 is closed by manual operation, it is actuated only by the time required to rotate the rotating drum 12 on which the photoreceptor is disposed by more than the required amount, preferably one or more revolutions, particularly preferably two or more revolutions. It consists of a timer. When the preparatory drive means 364 is activated, it supplies a signal to the main electric motor energizing circuit 366 to activate it. When the main electric motor energizing circuit 366 is activated, the main electric motor (not shown) is energized, which causes the rotary drum 12 to rotate in the illustrated electrostatic copying machine and also functions as a cleaning means. The developing device 24 is activated. In addition, in the illustrated electrostatic copying machine, when the main electric motor energizing circuit 366 is activated, the charge eliminating corona discharger 28 is activated.
The static elimination lamp 30 (FIG. 2) is also activated.

As such, the preparation drive means 3 according to the invention
In the illustrated electrostatic copying machine equipped with the electrostatic copying machine 64, when the copying process by the electrostatic copying machine is brought to an emergency stop due to the occurrence of a paper jam, the jammed copy paper is removed and the manual operation release switch 362 is activated. , the preparatory drive means 364 causes the rotary drum 12 to rotate more than the required amount, and the developing device 24, which also functions as a cleaning means, the static eliminating corona discharger 28, and the static eliminating lamp 30 rotate the rotating drum 12 by a predetermined amount. The rotation of the photoreceptor is opened, and thus, prior to performing the next copying process, residual charges and/or residual charges remaining on the photoreceptor due to the previous copying process that was interrupted due to the occurrence of a paper jam are removed. Toner particles are thoroughly removed.

The illustrated electrostatic copying machine is of a so-called current image transfer type; however, the preparation drive means 364 can be used not only for a current image transfer type electrostatic copying machine but also for an electrostatic latent image transfer type electrostatic copying machine. Needless to say, it is obvious that this can be applied to

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a specific example of an electrostatic copying machine constructed according to the present invention. FIG. 2 is a simplified sectional view of the electrostatic copying machine shown in FIG. 1. FIG. 3 is a block diagram illustrating the control electrical circuitry including the preparation drive means. 2...Housing 4...Manuscript! i! Device structure 12...Rotating drum 16...Electrostatic latent image forming area 18...Developing area 20...Transfer area 22...Charging corona discharger 24...Developing device 26... Transfer corona discharger 28... Static elimination corona discharger 30... Static elimination lamp 32... Optical system 46... Copy paper conveyance system 362... Manual operation release switch 364... Preparation drive means

Claims (1)

[Scope of Claims] 1. A housing, a photoreceptor disposed within the housing so as to be movable through an endless movement path defined within the housing, and a photoreceptor positioned along the movement path of the photoreceptor. a charging corona discharger for applying corona discharge to the photoreceptor in the electrostatic latent image forming area; an optical system for exposing the photoreceptor to light in the electrostatic latent image forming area; a copy paper conveyance system for conveying the copy paper through a predetermined conveyance path passing through a transfer area located along the movement path of the photoreceptor downstream of the electrostatic latent image forming area as viewed in the movement direction; Paper jam detection means for detecting a copy paper jam when it occurs in the copy paper conveyance path and generating a paper jam signal; and emergency stop means for stopping execution of the copying process in response to the paper jam signal. and a manual operation release switch for releasing the stop action of the emergency stop means; when the manual operation release switch is operated to release the stop action of the emergency stop means, the photosensitive An electrostatographic copying machine comprising a preparatory drive means for energizing a main electric motor drivingly connected to the body to move the photoreceptor through the endless travel path. 2. The electrostatic copying machine according to claim 1, wherein the preparation drive means comprises a preparation drive timer that operates for a predetermined period of time from the time when the manual operation release switch is operated. 3. On the photoreceptor in a development area located downstream of the electrostatic latent image forming area and upstream of the transfer area along the movement path of the photoreceptor when viewed in the direction of movement of the photoreceptor. A developing device is disposed for applying toner particles to develop the electrostatic latent image formed on the electrostatic latent image, and the developing device includes a cylindrical rotating sleeve drivingly connected to the main electric motor, and a rotary cylindrical sleeve disposed within the sleeve. a magnetic brush developer application mechanism that retains the developer on the circumferential surface of the sleeve by the action of a magnetic field generated by the magnet, and is formed on the photoreceptor. In addition to the development action of applying toner particles to an electrostatic latent image and developing it, toner particles remaining on the photoreceptor after the developed image formed on the photoreceptor is transferred to copy paper in the transfer area. An electrostatic copying machine according to claim 1 or claim 2, which also performs a cleaning action of removing.