JPH06175536A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain the copied image of high quality in an inexpensive structure and to eliminate a fear that the size of a device is made large, in the device provided with an image forming function except the copying function of a printer function, etc. CONSTITUTION:A light source 10 irradiating a material to be read B on an original supporting plate 2 with light is provided. On the outer peripheral side of the material to be read B, an exposing lens 11 guiding reflected light so as to irradiate a photosensitive drum 5 with the reflected light from the material to be read B is arranged. An exposing unit 12 composed of an LED 12a is disposed inside the photosensitive drum 5. When an action as a printer is taken, the photosensitive drum 5 is irradiated with the light by the exposing unit 12 in the photosensitive drum 5, to form an electrostatic latent image thereon. On the other hand, when a copy is made, the photosensitive drum 5 is directly irradiated with the reflected light from the material to be read on the original supporting plate 2 via the exposing lens 11, to form the electrostatic latent image on the drum 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic recording type image forming apparatus applied to, for example, a facsimile machine, a copying machine, a printer or the like.

[0002]

2. Description of the Related Art Conventionally, some image forming apparatuses of this type have two functions, for example, a printer function and a copy function. That is, when used as a printer, based on the input image data, a photoconductor is irradiated with light by an exposure device composed of a plurality of LEDs, and an electrostatic latent image is formed on the photoconductor. Then, toner is attached to the electrostatic latent image by the developing device, and the toner is transferred onto the sheet by the transfer device. Also, when making a copy,
The image on the object to be read is read by an image sensor such as a CCD, and the read image data is temporarily stored in the memory. Then, based on the image data in the memory, light is irradiated onto the photoconductor by the same exposure device as described above, and an electrostatic latent image is formed on the photoconductor. Then, as in the printing operation described above, toner is attached to the electrostatic latent image by the developing device, and the toner is transferred onto the paper by the transfer device.

[0003]

However, when copying is performed in the above conventional apparatus, the image on the object to be read is read by the image sensor, and the read image data is temporarily stored in the memory, and the memory is stored in the memory. An electrostatic latent image is formed by the exposure device based on the image data in the image. That is, the resolution of the copy image formed on the paper depends on the performance of the image sensor and the exposure device. Therefore, in order to improve the resolution of the copied image, it is necessary to use an expensive image sensor or an exposure device having excellent resolution, which causes a problem of increasing the manufacturing cost of the device. Further, in the conventional apparatus, since the image forming operation is started after the read image data is once stored in the memory, there is a delay from the start of reading the image on the object to the output of the copy image. It took a lot of time.

Therefore, when copying is performed, light is emitted from the light source onto the object to be read, and the reflected light from the object to be read is directly applied onto the photosensitive member through a lens or the like. It is also conceivable to adopt a so-called analog system for forming an electrostatic latent image on the same photoconductor. In this analog system, the image reading operation and the image forming operation are performed at the same time, so that it is possible to shorten the time until the copy image is output. Moreover, since the electrostatic latent image is formed by directly irradiating the photoconductor with the reflected light from the object to be read, it is possible to obtain a high-resolution copy image with an inexpensive structure.

However, around the photosensitive member, a charging device for uniformly charging the photosensitive member, an exposing device for forming an electrostatic latent image on the photosensitive member during printing, a developing device for forming a toner image, and a toner image on a paper sheet. Various devices such as a transfer device for transferring onto the top and a cleaner for cleaning the photoconductor are provided. Therefore, in addition to these devices, it is very difficult to secure an optical path around the photoconductor for guiding the reflected light from the object to be read onto the photoconductor due to the arrangement space. In addition, since the image forming operation is performed by a series of processes of each of the above devices, the position of the optical path is limited, and it becomes more difficult to secure the optical path. Further, in order to secure a light path by allowing a space for arrangement of each device, it is necessary to make the photosensitive member large, but this causes a problem that the device becomes large in size. Occur.

The present invention has been made to solve the above problems, and an object thereof is to provide a high quality copy image at a low cost in an apparatus having an image forming function other than the copy function such as a printer function. It is an object of the present invention to provide an image forming apparatus that can be obtained with various configurations and that does not cause an increase in size of the apparatus.

[0007]

In order to achieve the above object, in the present invention, image forming is provided with exposure means for irradiating a photoconductor with light to form an electrostatic latent image on the photoconductor. In the apparatus, the exposure means is provided on the outer peripheral side of the photoconductor, and first exposure means for guiding the reflected light from the object to be read onto the photoconductor and the inside of the photoconductor. And a second exposure means for irradiating the photoconductor with light from the inside thereof.

[0008]

Therefore, according to the present invention, when operating as a printer, for example, based on the input image data,
The second exposure means provided inside the photosensitive member irradiates the photosensitive member with light to form an electrostatic latent image on the photosensitive member. Further, when performing copying, the reflected light from the object to be read is guided onto the photoconductor by the first exposure means provided on the outer peripheral side of the photoconductor, and an electrostatic latent image is formed on the photoconductor. It is formed.

At the time of this copying operation, the reflected light from the object to be read is directly radiated onto the photoconductor through the first exposure means to form an electrostatic latent image, so that the structure is inexpensive. It is possible to obtain a high quality copy image.
Further, since the first exposure means is provided inside the photoconductor, only the second exposure means needs to be provided as the exposure means around the photoconductor, and two exposure means are provided around the photoconductor. There is no need to provide it. Therefore, it is not necessary to increase the diameter of the photoconductor in order to provide the two exposing means.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in an image forming apparatus having a printer function and a copy function will be described below with reference to the drawings.

As shown in FIG. 1, a document support base 2 made of a transparent glass plate or the like is supported on the upper part of the apparatus frame 1 so as to be capable of reciprocating in the horizontal direction (left and right direction in FIG. 1). An object to be read B such as a book is placed and supported on the table 2.
A rack 3 is fixed to one side of the document support table 2, and the pinion 4 meshing with the rack 3 is rotated in the forward and reverse directions by a moving motor 27 shown in FIG. Is moved back and forth to.

A photosensitive drum 5 as a photosensitive member is rotatably supported in the apparatus frame 1. The photosensitive drum 5 is provided on the outer peripheral surface of a transparent cylindrical body 6 made of glass or the like.
Similarly, it is formed by forming a transparent electrode layer 7 and a photoconductive layer 8. The charger 9 is arranged to face the outer periphery of the upper portion of the photosensitive drum 5, and uniformly charges the photoconductive layer 8 to a predetermined potential.

A light source 10 made of a fluorescent lamp or the like is fixedly arranged in the apparatus frame 1, and when the original support 2 is moved in one direction,
The object B to be read on the support base 2 is irradiated with light through the support base 2. Exposure lens 11 as first exposure means
Is formed by arranging a large number of rod lenses 11a in parallel, and is arranged so as to be adjacent to the charger 9 and to face the outer periphery of the upper portion of the photosensitive drum 5.

Then, the reflected light of the light emitted from the light source 10 to the object to be read B is guided to the exposure lens 11 through the document support base 2 and is also irradiated onto the photosensitive drum 5 via the exposure lens 11. The photoconductive layer 8 is exposed. As a result, an electrostatic latent image having a predetermined potential corresponding to the image on the object B to be read is formed on the photoconductive layer 8.

The exposure device 12 as the second exposure means comprises a large number of LEDs 12a arranged side by side, and is arranged inside the photosensitive drum 5 so as to face the exposure position of the exposure lens 11. Then, the exposure device 12 irradiates the photoconductive drum 5 with light from the inner surface of the photoconductive drum 5 to expose the photoconductive layer 8, and the photoconductive layer 8 is exposed to the electrostatic latent image of a predetermined potential. An image is formed.

The developing device 13 has a toner case 14 for accommodating the toner T, and a developing roller 15 arranged at the lower end opening of the toner case 14 so as to closely face the outer periphery of the side of the photosensitive drum 5. is doing. Then, a predetermined potential is applied to the toner T by the developing roller 15, the toner T is attached to the electrostatic latent image based on the difference between the potential and the potential of the electrostatic latent image, and the electrostatic latent image becomes the toner. It is visualized as an image.

In the present embodiment, the regular developing system is adopted, and on the photoconductive layer 8 of the photosensitive drum 5, a portion other than the portion exposed by the exposure lens 11 and the exposure device 12 and having the potential lowered is electrostatic. It becomes a latent image. Therefore, in the above-described developing step, the toner T is attached to the unexposed portion of the photoconductive layer 8.

The transfer roller 16 is rotatably arranged so as to face the outer periphery of the lower portion of the photosensitive drum 5. Then, the paper P transferred from a paper supply unit (not shown) such as a paper feed cassette via the pair of feed rollers 17 and the like,
The transfer roller 16 makes close contact with the outer periphery of the photosensitive drum 5. At the same time, a predetermined potential is applied to the contact portion by the transfer roller 16, and the toner image is transferred onto the paper P based on the difference between the potential and the potential of the toner image.

The discharging lamp 18 is used for the photosensitive drum 5 after the transfer.
The outer peripheral surface of is irradiated with light to eliminate the electric charge. The cleaner 19 cleans the toner T remaining on the photosensitive drum 5 after transfer.

The heat fixing device 20 is disposed downstream of the photosensitive drum 5, and has a positively rotatable heating roller 21 and a pressure roller 22 which comes into contact with the heating roller 21 with a sheet transfer path interposed therebetween. ing. Then, the paper P is sent between the heating roller 21 and the pressure roller 22, and the toner image on the paper P is heated and fixed. The sheet P after the image fixing is sent out of the apparatus via a guide roller or the like (not shown).

The photosensitive drum 5, the developing roller 15,
Transfer roller 16, feed roller 17, and heating roller 21
Is rotationally driven by a drive motor 28 shown in FIG. 2 via a gear transmission mechanism or the like (not shown).

Next, the circuit configuration of the main components of the image forming apparatus will be described. The control circuit 25 is for controlling the operation of the entire apparatus. Image data is externally input to the control circuit 25. Also, the control circuit 25
From the above, the moving motor 27, the drive motor 28, the light source 10, the exposure device 12, the charge eliminating lamp 18, and the heat fixing device 2
For 0, an operation or stop signal is output. Further, the control circuit 25 applies a predetermined potential to the charger 9, the developing roller 15, and the transfer roller 16. A key input unit 26 is connected to the control circuit 25, and various operation keys such as a copy key 26a for starting a copy operation are provided in the key input unit 26.

Then, when image data is input from the outside, the control circuit 25, based on the input image data,
Start the printing operation. That is, the control circuit 25 operates the drive motor 28, the exposure device 12, the charge eliminating lamp 18, and the heat fixing device 20, and at the same time, applies a predetermined potential to the charger 9, the developing roller 15, and the transfer roller 16 to move them. The motor 27 and the light source 10 are not operated. Therefore, the photoconductive layer 8 is exposed from the photosensitive drum 5 by the exposure device 12, an electrostatic latent image based on the input image data is formed on the photoconductive layer 8, and the paper P is formed on the basis of the electrostatic latent image. A toner image is formed on.

On the other hand, if the copy key 26a is operated while the object B to be read is placed on the original support table 2, the control circuit 25 performs a copy operation based on the image on the object B to be read. Let it start. That is, the control circuit 25 includes the moving motor 27, the drive motor 28, the light source 10, the static elimination lamp 18,
And the heat fixing device 20 is operated, and the charging device 9,
A predetermined potential is applied to the developing roller 15 and the transfer roller 16, and the exposure device 12 is not operated. Therefore, the document support table 2
When moving in one direction, light is emitted from the light source 10 to the object to be read B on the support base 2, and the reflected light is emitted to the photosensitive drum 5 via the exposure lens 11 to cause photoconduction. The layer 8 is exposed. Thereby, on the photoconductive layer 8,
An electrostatic latent image corresponding to the image on the object to be read B is formed, and a toner image is formed on the paper P based on the electrostatic latent image.

When the image forming apparatus configured as described above operates as a printer, the exposure device 12 provided inside the photosensitive drum 5 causes the image to be formed on the photosensitive drum 5 based on the input image data. By being irradiated with light, an electrostatic latent image is formed on the drum 5. On the other hand, when making a copy, the reflected light from the object B to be read on the original support 2 is directly radiated onto the photosensitive drum 5 via the exposure lens 11, so that an electrostatic latent image is formed on the drum 5. An image is formed.

Therefore, unlike the conventional printer having two functions of a printer function and a copy function, when copying is performed, an image on an object to be read is read by an image sensor and the read image data is read. It is not necessary to temporarily store in the memory and form an electrostatic latent image by the exposure device based on the image data in the memory. Therefore, the resolution of the copy image does not depend on the performance of the image sensor or the exposure device, and by adopting the so-called analog method in which the electrostatic latent image is formed by direct irradiation of the reflected light from the object B to be read. A high-resolution copy image can be obtained with an inexpensive structure. In addition, the image forming operation is not started after the read image data is once stored in the memory, and the image reading operation and the image forming operation are performed at the same time. It takes only a short time to output.

Further, in this embodiment, there are provided two exposing means, that is, the exposing device 12 used during the printing operation and the exposing lens 11 used during the copying operation. However, since the exposure device 12 is provided inside the photosensitive drum 5, only the exposure lens 11 needs to be provided as an exposing means around the photosensitive drum 5, and it is not necessary to provide two exposing means around the drum. . Therefore, despite the provision of the two exposure means, the number of devices arranged around the photosensitive drum 5 does not increase as compared with a normal electrophotographic recording type process unit. Therefore, there is no fear of complicating the configuration, and it is not necessary to increase the diameter of the photosensitive drum 5 in order to provide the two exposing means, and hence there is no fear of increasing the size of the apparatus.

The present invention is not limited to the above-mentioned embodiment, and the configurations of the respective parts can be modified and embodied as follows without departing from the gist of the present invention. (1) In the above embodiments, the image forming apparatus having the copy function and the printer function is embodied, but in addition to that, the facsimile communication function is added. Specifically, in addition to the configuration of the above embodiment, it comprises a modem for modulating and demodulating transmitted / received image data, an NCU for controlling the connection of a telephone line, a CCD for reading an image on the object B to be read, and the like. Provide an image sensor, etc.

In this case, the received image data is recorded on the paper P based on the light irradiation onto the photosensitive drum 5 by the exposure device 12. Alternatively, image data read by the image sensor may be temporarily stored in the memory, and the exposure device 12 may perform exposure based on the image data in the memory to form an image. That is, not only can the copy be performed in real time based on the exposure by the exposure lens 11, but the read image data can be stored in the memory and then appropriately output as a copy image based on the exposure by the exposure device 12. . (2) To be embodied in an apparatus having a copy function and a facsimile communication function without providing a printer function.

[0030]

As described above in detail, according to the present invention, in an apparatus having an image forming function other than the copy function such as a printer function, a high quality copy image can be obtained with an inexpensive structure. Moreover, it has an excellent effect that there is no fear that the size of the device is increased.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of an image forming apparatus embodying the present invention.

FIG. 2 is a block diagram showing a circuit configuration of main components of the image forming apparatus.

[Explanation of symbols]

5 ... Photosensitive drum as photoconductor, 11 ... Exposure lens as first exposure means, 12 ... Exposure device as second exposure means, B ... Object to be read.

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical indication location G03G 15/00 115 15/04 111 9122-2H H04N 1/29 Z 9186-5C

Claims (1)

[Claims] 1. An image forming apparatus comprising an exposing means for irradiating light on a photoconductor to form an electrostatic latent image on the photoconductor, wherein the exposing means is provided on an outer peripheral side of the photoconductor. A first exposure unit that guides the reflected light from the object to be read so that the reflected light is irradiated onto the photosensitive member; and a second exposure unit that is provided inside the photosensitive member and irradiates the photosensitive member with light from the inside. And an image forming apparatus including the exposing unit.