JPH0721672B2 - Charge erasing means supporting device for image forming apparatus - Google Patents

Description

The present invention relates to a charge erasing means supporting device for an image forming apparatus in which an image carrier is removable.

(B) Conventional Technology Some image forming apparatuses such as copying machines have a charge erasing unit for erasing charges in an unnecessary image area on an image carrier such as a photosensitive drum. This unnecessary image area is an unexposed area that occurs at the edge of the photosensitive drum when variable-magnification copying is performed, or a specific unnecessary specified when copying with image editing such as masking or trimming. Areas, etc. In particular, in recent years, many light emitting diode (LED) arrays have been used as charge erasing means, and it has become possible to erase unnecessary images with high resolution. But this LED
Since the array emits a small amount of light, it is necessary to bring the array close to an image carrier such as a photosensitive drum in order to secure the amount of light necessary for erasing charges. In addition, especially when performing image editing, the LED array is approximately 1 to 2 mm from the photosensitive drum because the boundary between the required image area and the unnecessary image area must be made clearer.
It is necessary to dispose them close to each other. Therefore, when the photoconductor drum is attached or detached, there is a problem that the photoconductor drum comes into contact with the LED array or the supporting member thereof and is easily damaged.

In order to solve this problem, Japanese Patent Application Laid-Open No. 60-32080 discloses a method of separating the photosensitive drum and the LED array.

(C) Problems to be Solved by the Invention In short, the one disclosed in Japanese Patent Laid-Open No. 60-32080 is a shift mechanism support fixed to the main body of the image forming apparatus, and this shift mechanism support. It comprises a sliding means disposed on the body and sliding in a predetermined direction, and a charge erasing means which is interlocked with the sliding of the sliding means and shifts in a direction away from the image carrier. Is very complicated,
Further, with this configuration, it is difficult to make the distance between the image carrier and the charge erasing means sufficiently large.

Also, if such an image forming device is used for a long time, the LED
Since the light emitting surface of the array becomes dirty due to toner adhesion and the like, it is necessary to regularly clean the light emitting surface, but in the above publication, no consideration is given to such a case.

Therefore, a main object of the present invention is to provide a charge erasing means supporting device for an image forming apparatus, which is configured to solve the above-mentioned problems with a simple structure.

(D) Means for Solving the Problems In order to solve the above problems, the present invention provides a detachable image carrier and an unnecessary charge on the image carrier, which is disposed close to the image carrier. In the image forming apparatus provided with the charge erasing means for erasing, the charge erasing means is rotatably installed in the vicinity of the detachable developing means with an axis parallel to the rotation axis of the image carrier as a spindle. It is characterized in that it is rotated toward the space formed when the developing means is detached.

(E) Action As described above, the charge erasing means is rotatably installed in the vicinity of the detachable developing means with the shaft parallel to the rotation axis of the image carrier as a support shaft, and is in the detached state of the developing means. By rotating to the formed space side, not only the charge erasing means and the image carrier can be easily separated by a sufficient distance, but also the space can be secured in the rotated state.

(F) Embodiment FIG. 1 is an overall configuration diagram of one embodiment of the present invention used in an electronic copying machine. The details of the operation of the electronic copying machine and the like will be omitted here, and only the configuration around the photosensitive drum, which is the image carrier, will be briefly described.

Reference numeral (1) is a photosensitive drum, which rotates in the direction of arrow (A) about the axis (2). Photoconductor drum (1)
A charging corotron (3), a light source (4), and a short focus lens array (5) are provided around the photosensitive drum (1) to transfer an electrostatic latent image of the original placed on the original table (6) to the photosensitive drum (1). ) Is formed on the peripheral surface. After that, a toner image corresponding to the electrostatic latent image is formed on the photosensitive drum by the developing device (7), and the toner image is transferred to a transfer paper (not shown) by the transfer corotron (8). After that, the toner remaining on the peripheral surface of the photosensitive drum is scraped off by the cleaning blade (10) provided in the cleaning unit (9),
The static elimination LED array (11) is turned on to eliminate residual charges on the peripheral surface of the photosensitive drum.

(12) is an LED array which is a charge erasing means, and is composed of LED chips (13) each having a width of about 4 mm arranged continuously along the longitudinal direction of the photosensitive drum (1). There is. The copying machine of this embodiment is not equipped with a variable-magnification copying function, and this LED array (12) is used for image editing and copying. For example, an electrostatic latent image formed on the photosensitive drum (1) is used. When it is desired to erase only a specific designated area in the latent image, the LED chip corresponding to the position of the designated area may be turned on while synchronizing with the rotation speed of the photosensitive drum (1). At this time, in order to clarify the boundary between the illuminated area and the non-illuminated area on the photoconductor drum by the lighting LED chip, the distance between the LED chip (13) and the photoconductor drum (1) is close to 1 to 2 mm. Need to let. The LED array (12) is rotatable about the shaft (14) as a fulcrum, which will be described later in detail.

The photoconductor drum (1) is detachable along the rotation shaft (2) thereof, and the charging corotron (3), the developing device (7), and the cleaning unit (9) can be installed in appropriate ways. It is configured to be removable.

The present invention will be described below in the copying machine configured as described above.

2 is a configuration diagram of only a main part around the photosensitive drum (1) in FIG. 1, and FIG. 2 (a) is a front view seen from the axial direction of the photosensitive drum (1). FIG. 1B is a plan view thereof. However, the side views (20) are omitted in all of the front views in FIGS. 2 to 6 below. Unlike FIG. 1, FIG. 2 is not a cross-sectional view, and therefore has a slightly different shape. (1) is a photosensitive drum, (7) is a developing device, (9) is a cleaning unit, and (4) is a light source. The supporting members (15) and (16) of the light source (4) include a charging corotron (3), a short focus lens array (5), and an LED.
An array (12) is installed. LED array (12)
An end portion of the LED array (12) is rotatably installed around a shaft (14) as a fulcrum on another support member (17) (18) fixed to the support member (15) (16). It can be easily rotated by a lever (19) fixed to the.
(20) and (21) are side walls of the copying machine body. The figure shows a case where the LED array (12) is in a normal use position, and in this state, the lever (19) prevents the photosensitive drum (1) from being disengaged along the axis (2). I understand. In other words, the LED array (12) is the photosensitive drum (1)
The photoconductor drum (1) cannot be detached when the photoconductor drum (1) is close to.

In a normal use state, the bearing member for holding the shaft (1) of the photoconductor drum is attached to the side wall (2
It is installed in 0), but it is not shown here.

When the photosensitive drum (1) is to be removed in this state, the lever (19) is rotated counterclockwise as shown in FIG. As a result, the LED array (12) also has the axis (1
It is rotated about 4) as a fulcrum, and a sufficient space is formed between it and the photosensitive drum (1). In this state, as is apparent from the figure, the photoconductor drum (1) is connected to the lever (19).
Therefore, the photoconductor drum (1) can be easily pulled out along the shaft (2) because the removal thereof is not hindered.

In order to extract the photosensitive drum (1) more safely, all of the developing device (7), the charging corotron (3), and the cleaning unit (9) as shown in FIG. It is desirable to separate from the surroundings of 1).

Next, a case where the photosensitive drum (1) is detached and then the photosensitive drum is mounted again will be described.

FIG. 5 shows the state after the photoconductor drum (1) is mounted. As described above, the cleaning unit (9), the charging corotron (3), the developing device (7) and the like are essential for image formation. Since it is an element that cannot be forgotten, it is thought that their mounting will not be forgotten and can be done with relative certainty. However, like the LED array (12) in this invention, the one that is simply rotated is the original state. It is easy to forget to return to. Therefore, by using the bearing member (22) for holding the shaft (2) of the photosensitive drum (1),
It prevents you from forgetting to return the LED array (12) to its original position. The bearing member (22) has a bearing portion (23),
The shaft (2) is positioned by inserting the shaft (2) of the photosensitive drum into the hole (24) (2
5) is aligned with a screw hole (not shown) provided in the side wall (20) and is fixed to the side wall (20) with screws (26) (27) as shown in FIG. is there. However, the side wall (20) is not shown in FIGS. 5 (a) and 6 (a). Now, as shown in FIG. 5, when it is attempted to mount the bearing member (22) while rotating the LED array (12) counterclockwise and keeping it separated from the photosensitive drum (1), As shown in FIG. 5 (b), the lever (19) is formed by the bearing member (22) and the recess (28) is formed.
Therefore, the bearing member (22) cannot be mounted. That is, if the bearing member (22) is to be installed at a proper position, the end portion (29) of the lever and the bottom portion (30) of the holding member come into contact with each other.

On the other hand, as shown in FIG. 6, when the LED array (12) is installed in the proper use position by rotating the lever (19) clockwise, the lever (19) moves to the bearing member (22). The bearing member (22) is mounted at an appropriate position on the side wall (20) and can be fixed by the screws (26) and (27) so as to be engaged with the recessed portion (28) formed in the.

Next, another effect of the present invention will be described. In general,
It is inevitable that the optical system and the like will be contaminated by the adhesion of the toner powder when the image forming apparatus for dry development is used for a long time. In particular, as in the embodiment of the invention,
When the LED array for charge erasing is arranged near the developing device, toner is inevitably attached to the light emitting surface thereof, and depending on the degree, the charge erasing action is adversely affected.

FIG. 7 shows a method for cleaning the light emitting surface of the LED array in order to deal with this problem, and shows a configuration diagram around the photosensitive drum (1). LED array (12)
If the light-emitting surface (31) of is dirty, first set the original platen (6).
Is moved in the direction of arrow (B), then the inner lid (32) is opened in the direction of arrow (C), and a developing device (not shown) is taken out in the direction of arrow (D). The alternate long and short dash line (33) shows the position where the developing device was installed, and in this state, a wide space is formed at this position.
As described above, the bearing member (not shown) is removed and the lever (not shown) is rotated to rotate the LED array (12) counterclockwise about the shaft (14) as a fulcrum. At the same time as separating from (1), the light emitting surface (31) is moved closer to the space formed by taking out the developing device. After that, the hand can be inserted into the main body of the copying apparatus as shown by the arrow (E), and the light emitting surface (31) can be cleaned with a suitable cloth or the like.

Although the embodiment of the present invention has been described above, the charge erasing means may be one for erasing an unnecessary area during variable-magnification copying, or may be a normal discharge lamp. Is.

(G) Effect of the Invention As described above, according to the present invention, the charge erasing unit and the image carrier can be easily and sufficiently separated with a simple structure, and an image can be safely generated. The carrier can be attached and detached.

Further, since the charge erasing means is rotated toward the space formed when the developing means is detached, the side of the charge erasing means facing the image carrier faces the space secured in the rotated state to clean the worker. Space can be provided.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an example of a copying machine as an embodiment of the present invention. FIG. 2 is a block diagram of the charge erasing means of the embodiment of the present invention. FIG. 3 and FIG. 4 are operation explanatory views of the charge erasing means of the embodiment of the present invention. 5 and 6 are explanatory views showing another effect by the embodiment of the present invention. FIG. 7 is an explanatory view showing still another effect by the embodiment of the present invention. In the figure, (1) is a photosensitive drum, (12) is a charge erasing LED array, (14) is a rotation axis of the LED array, and (19) is a LE.
The lever for D array rotation, (22) indicates a bearing member.

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-60-32080 (JP, A) JP-A-56-155952 (JP, A) JP-A-60-181756 (JP, A) JP-A-59- 151170 (JP, A) JP 62-258477 (JP, A) JP 61-145576 (JP, A) JP 62-209546 (JP, A) Actual development JP 56-88243 (JP, U) Actual opening Sho 59-38456 (JP, U) Actual opening Sho 62-149046 (JP, U) Actual opening Sho 58-144363 (JP, U) Actual opening Sho 63-4551 (JP, U) Actual opening Sho 54-1251 (JP, Y2) Jitsuko Sho 54-22437 (JP, Y2)

Claims (1)

[Claims] 1. An image forming apparatus comprising a detachable image carrier and a charge erasing unit which is disposed in the vicinity of the image carrier and erases unnecessary charges on the image carrier. Is rotatably installed in the vicinity of the detachable developing means with a shaft parallel to the rotation axis of the image carrier as a support shaft, and is rotated toward the space formed in the detached state of the developing means. An apparatus for supporting charge erasing means of an image forming apparatus, characterized in that.