JPH0623877B2 - Digital image forming device - Google Patents

Description

The present invention relates to a digital image forming apparatus in which a writing unit can be independently attached to and detached from an apparatus main body.

[Background of the Invention]

A digital image forming apparatus is roughly classified into a reading device that sequentially forms an optical image obtained by exposure scanning of a document surface on a line image sensor and outputs the document image as an electrical image signal, and a reading device that receives the image signal. A writing unit for scanning and projecting an optical image by a laser beam of a semiconductor laser on a surface of a photoconductor to form an electrostatic latent image of an original on the photoconductor, and further developing and transferring the latent image including the photoconductor described above and cleaning systems. It is composed of each part of an image forming unit that controls image processing.

Each of these parts is fixed in a stacked state due to the space, and is formed as a device.
Regarding the arrangement of the respective parts, the reading device is located at the uppermost position because of the provision of the document table, and the image forming section occupies the lowermost position because the volume and weight are large, as is well known, and therefore the writing unit is the same. It is common that it is attached in a form sandwiched between the two.

[Problems to be solved by the invention]

On the other hand, since the writing unit houses many optical components such as a rotary polygon mirror, they are often removed from the image forming apparatus for cleaning or replacing the components.

However, for its removal, it is necessary to remove and place it with the reading device fixed above for the above-mentioned reason, so that the work requires a lot of labor and time.

As a result of solving and improving this point, an object of the present invention is to provide a digital image forming apparatus in which only a writing unit can be independently attached to and detached from an image forming apparatus without removing a reading device.

[Means for solving problems]

The above-mentioned object is to provide a reading device which is provided with a document table, converts a light image obtained by exposing and scanning the document surface on the document table into an electric image signal and outputs the image signal, and a reading device which receives the image signal from the reading device. A writing unit for scanning and projecting an optical image by a laser beam onto the surface of the photoconductor drum to form an electrostatic latent image of an original on the photoconductor, and an image forming unit for forming an image on the surface of the photoconductor drum. In a digital image forming apparatus in which the reading device is disposed on the upper surface and the writing unit is provided between the reading device and the image forming unit, the writing unit is detachable from the apparatus main body in the lateral direction. A position reference member for providing positional accuracy of the writing unit with respect to the photosensitive drum is provided between the device body and the tip of the writing unit, and the position reference member is provided outside the device body by the fastening member. Rank Is accomplished by the digital image forming apparatus characterized by in contact with the reference member configured to fixedly said writing unit.

〔Example〕

 One embodiment of the present invention is shown in FIGS. 1 and 2.

FIG. 2 shows the structure of a digital image forming apparatus of the color system, in which a color image is formed as follows.

In FIG. 2, A is a reading device, B is a writing unit,
C is an image forming unit, and D is a paper feeding unit.

In the reading device A, 1 is a platen glass, and the original 2 is placed on the platen glass 1. The original 2 is illuminated by fluorescent lamps 5 and 6 provided on a carriage 4 that moves on a slide rail 3. Movable mirror unit 8
Mirrors 9 and 9'are provided on the slide rail 3 to move the first mirror 7 on the carriage 4.
The light image of the original 2 on the platen glass 1 is led to the lens reading unit 20 in combination with.

The carriage 4 and the movable mirror unit 8 are driven by a stepping motor 10 via a wire 15;
12, 13, 14 are driven in the same direction at speeds of V and 1/2 V, respectively. Standard white plates 16 and 17 are provided on the back surfaces of both ends of the platen glass 1 so that a standard white signal can be obtained before the start of scanning the document and after the scanning.

The lens reading unit 20 includes a lens 21 as a reading lens system, a prism 22 as a photolytic means, a first reading substrate 24, a red channel (hereinafter referred to as R-ch) CCD 25 which is a line image sensor, a second reading substrate 26, and cyan. It is composed of a channel (hereinafter referred to as C-ch) CCD27.
The original light image transmitted by the first mirror 7, the mirror 9, and the mirror 9'is focused by the lens 21, and the R-ch image and the C-ch image are formed by the dichroic mirror provided in the prism 22.
R- which is separated into an image and is provided on the first reading substrate 24.
chCCD25 and C-chCCD provided on the second reading substrate 26
An image is formed on each of the 27 light-receiving surfaces.

As the fluorescent lamps 5 and 6, commercially available warm white fluorescent lamps are used to prevent a specific color from being emphasized or attenuated depending on the light source when reading a color original document, and are turned on by a high frequency power source of 40 KHz to prevent flicker. It is kept warm by a heater using a posistor to keep the tube wall at a constant temperature or to promote warm-up.

The image signals output from the R-ch CCD 25 and the C-ch CCD 27 are processed by a signal processing unit (not shown), and color signals separated according to the toner color are output and input to the writing unit B. And an image by the laser beam generated by the semiconductor laser is sequentially projected on the peripheral surface of the photosensitive drum 31, and the developing rollers I and I are respectively projected for each projection.
A color image with three color toners is formed through development processing by I and III.

Then, the color image on the peripheral surface of the photoconductor drum 31 is transferred to the recording paper conveyed from the paper feed section D at the transfer separation pole 32, and then the recording paper is separated and discharged to the outside of the apparatus via the fixing device 33. The reproduction of the color image is completed.

In the digital image forming apparatus, the reading apparatus A is integrally attached to form the apparatus main body 50 having the outline of the shape shown by the alternate long and short dash line in FIG. 1. A rectangular opening 51, which is also shown by a one-dot chain line, is provided in a portion corresponding to the writing unit B, and the writing unit B is unitized through the opening 51 and can be attached to and detached from the apparatus main body 50. I am trying.

That is, in the portion corresponding to the writing unit B, a deep space having the opening 51 as a frontage is provided, and the bottom surface of the space guides the attaching / detaching operation of the writing unit B and fixes it in the mounting position. The backing plate 60 is fixed.

The receiving plate 60 is formed by integrally forming a rising portion 61 on both side surfaces of the flat bottom portion when viewed in the lateral direction, and a falling portion 62 on both sides of the notch 62a on the front side. The portion 62 is fixed in a state of being in contact with the side surface of the device body 50.

On the other hand, a substrate 70 for the writing unit B having a sufficient flatness with a sufficient thickness is prepared separately from the receiving plate 60, and the writing unit B is configured with respect to the substrate 70 in a single state. Laser oscillator 81, rotating polygon mirror 82, fθ
The lens 83, the cylindrical lens 84, the reflecting mirror 85, and other constituent members can be attached to form a sub-assembly.

Since the substrate 70 has a width dimension that slides in contact with the rising portion 61 of the receiving plate 60, the substrate 70 maintains the optical axis position of the writing unit B when inserted into the opening 51. It is accommodated in 50 and the depth is a pair of notches 73 provided in the substrate 70.
Is determined at the position where it abuts on the stop pin 63 which is a position reference member fixed to the receiving plate 60.

Further, the substrate 70 is in a state of being pressed downward by the pair of left and right holding plates 65, which are elastic members attached to the rising portion 61 of the receiving plate 60, at the position where the substrate 70 is accommodated in the receiving plate 60. , A front side portion 71 that shields the front surface of the upper substrate 70.
A pair of left and right protrusions 72 derived downward from the receiving plate 60.
As a fastening member to be screwed to the falling portion 62, for example, a small screw 75 having a head with a large outer diameter dimension is tightened in the lateral direction to be tightly fixed.

That is, at the position where the substrate 70 is fixedly attached to the receiving plate 60, the writing unit B incorporated on the substrate 70 automatically occupies the prescribed relational position with respect to the image forming section C in the apparatus main body 50. In other words, the optical image of the original screen projected from the writing unit B through the cable connection with the reading device A passes through the slits 74 and 65 of the substrate 70 and the receiving plate 60 which are aligned with each other to form the photoconductor. It reaches the peripheral surface of the drum 31 and is formed as an electrostatic latent image.

When the cable connection with the reading device A is released and the above-mentioned fastening member is removed, the substrate 70 can be easily pulled out, and the writing unit B can be easily taken out from the device main body 50 to perform cleaning or parts replacement work. Can be carried out easily.

〔The invention's effect〕

According to the present invention, the work of attaching / detaching the writing unit part to / from the main body of the apparatus is extremely simple, and therefore, the work such as cleaning, inspection and replacement of parts is performed thoroughly, and a digital image forming apparatus having high performance and excellent image quality is provided. became.

[Brief description of drawings]

 FIG. 1 is a perspective view of an essential part of a digital image forming apparatus of the present invention. FIG. 2 is a sectional configuration diagram of the device. A: reading device B: writing unit C: image forming unit D: paper feeding unit 50: device body 60: receiving plate 61: rising part 62: falling part 63: stop pin 70 …… Substrate 72 …… Projection 73 …… Notch

Claims (1)

[Claims] 1. A reading device comprising a document table, which converts an optical image obtained by exposing and scanning the document surface on the document table into an electric image signal and outputs the image signal, and an image signal from the reading device. A writing unit that receives and scans and projects as a light image by a laser beam on the surface of the photoconductor drum to form an electrostatic latent image of an original on the photoconductor, and an image forming unit that forms an image on the surface of the photoconductor drum are provided. In the digital image forming apparatus, in which the reading device is disposed on the upper surface and the writing unit is provided between the reading device and the image forming unit, the writing unit is attached / detached laterally to / from the apparatus body. A position reference member for providing the positional accuracy of the writing unit with respect to the photosensitive drum is provided between the main body of the apparatus and the tip of the writing unit, and by a fastening member attached to the outside of the main body of the apparatus. The above A digital image forming apparatus, wherein the writing unit is fixedly mounted in a state of being in contact with a position reference member.