JPH02220072A - Writing optical device installing device for image forming device - Google Patents

Abstract

PURPOSE:To facilitate inserting a reference pin and to improve positioning accuracy by providing a taper part, which is engaged with a taper part of the reference pin, in a reference hole on the writing optical device side when combined. CONSTITUTION:For an installation stay 37, the reference hole provided with a reference hole part 37a and a screw part 37a on the same axis is provided. On the reference side installation part 31 of an optical device 12, a taper hole 32 whose top is widened is provided, and for an installation part 33 following the reference, an oblong hole 34 with a taper is provided. On the reference pin 36, a taper part 36a whose top is widened and that possesses a same taper as the reference hole taper part is provided. The taper part 36a of the reference pin 36 is fitted in the taper part of the optical device side reference holes 32 and 34, positioned, adhered and fixed by inserting and screwing down the reference pin 36 into the optical device side reference hole 32 and 34 from the top.

Description

DETAILED DESCRIPTION OF THE INVENTION Production 2 - The present invention provides a color image recording device having a plurality of latent image carriers and a writing optical device in which a single casing is provided with an emitting section for writing and scanning a light beam on the latent image carriers. Mounting the writing optics of the forming device relates to the device.

One of the color image forming apparatuses using the 1 to 1 Arashi electrophotographic process is equipped with a plurality of photoreceptors (latent image carriers).

Optical writing is performed on these photoconductors using a laser beam modulated by image information signals obtained by color-separating the original, and toner images of different colors formed on each photoconductor by an electrophotographic process are printed on each photoconductor. There is an image forming apparatus using a color separation image superimposition transfer method in which color images are superimposed and transferred by aligning the images onto transfer sheets that are conveyed in sequential contact with a photoconductor, and are fixed to form a color image.

FIG. 1 is a diagram showing a schematic configuration of one example.

This device consists of a document reading section 1, an image processing section 2, and a printer section 3.

A Kalani original placed on the original placing table 4 of the original reading section 1 is optically scanned by a white lamp 5, and the reflected light is
．． 2.3 Through the mirror 6.7.8 and lens 9, the dichroic prism 10 separates the light into three color lights of blue, green, and red, and each color light is imaged and read on COD, 11B, 11G, and IIR, Output as a digital signal.

The digital signals of each color are subjected to necessary processing in the image processing section 2, and the digital signals of each color (hereinafter referred to as Y, M
, C, BK) are converted into image information signals to be developed, inputted to the laser fighting section of the laser writing optical device 12 of the printer section 3, and modulated by the image information signals of each color by the semiconductor laser. Laser beam 24Y, 24M,
24C124BK is emitted. Each laser beam is incident on one of two rotating polygon mirrors, and the Fθ lens 26
Y, 26M, 26G, 26BK; After passing through the mirror 27, the light is emitted from an exit opening extending in the main scanning direction in the writing optical device casing at a position opposite to the writing position of the photoreceptors 14Y, 14M, and 14C114BK, respectively. , main scan each photoreceptor drum. Each photoreceptor drum 14 (subscripts Y, M,
C and BK indicate equipment attached to the photoreceptor to be developed in yellow, magenta, cyan, and black, respectively, and will be omitted hereinafter. ), a charging charge 15, the writing position, a developing device 16, and a transfer charger 17 are provided to constitute a four-color recording device 13. The paper feed section 1 is fed by the paper feed roller 18.
The transfer paper sent out from 9 is conveyed by a transfer belt 21 via a register roller 20 and sequentially through a transfer section between each transfer charger 17 and a photoreceptor 14, and at each transfer section BK, C, M, Y is transferred. After the toner images of each color are aligned and transferred, they are fixed by the fixing device 22 and discharged from the machine by the discharge roller 23, thereby completing the recording.

In the overlapping transfer type color image forming apparatus having the above configuration, the colors and images of the document are reproduced by overlapping the toner images of four colors, so that the laser emitted from each exit of the laser writing optical bag Wt12 If the main scanning range of light does not match the width direction of the photoreceptor drum, color shift occurs and the quality of one image deteriorates. Therefore, before attaching the laser writing optical device to the main body of the image forming apparatus, the exposure scanning range of the four color image lights is adjusted using a jig, etc., and then the laser writing optical device is prepared with a reference pin. The image forming apparatus is accurately positioned and attached to the image forming apparatus using the holes.

FIGS. 2(a) and 2(b) are diagrams showing an example of a conventional positioning and mounting apparatus for a laser writing optical device.

Writing optical bag! ! Reference numeral 12 attaches left and right mounting portions 33 and 31 of the writing optical device to a pair of left and right stays 37 extending between the front and rear side plates of the printer section 3 of the main body of the image forming apparatus.

It is placed so that the center of the reference hole 34.32 drilled in the mounting part coincides with the reference hole 37a bored in the stay 37, and the reference pin 35 is inserted from above and the threaded part 35C provided at the end thereof. The stay 37 is positioned and attached to the printer section of the image forming apparatus by being screwed into the internal threaded portion 37b formed at the lower part of the reference hole 37a of the stay 37 and tightened.

By the way, conventionally, the reference hole and the reference pin are straight, and from the viewpoints of replacement of the writing optical device i12, ease of assembly, prevention of deformation due to thermal expansion, etc., it is difficult to fit the reference hole 32, 34 on the optical device side and the reference pin 35. A clearance fit is usually used. Further, in order to release the difference in thermal expansion caused by the temperature difference between the optical device and the image forming device, one of the reference holes (sub-reference side) on the optical device 12 side is an oval hole. Figure 2(a)
As shown, the optical device! ! There is a gap C1 between the reference hole 32 drilled in the right side (reference side) attachment part 31 of 12 and the straight cylindrical part of the reference pin 35, and there is an ellipse bored in the left side (sub-reference side) attachment part 33. Short diameter part of hole 34 and reference pin 35
If there is a gap C2 between the optical device! The fixed position of 12 varies within this range with respect to the main body of the image forming apparatus.

The optical device 12 is fixed to a jig at the position shown by the solid line in FIG.
Assume that the positions of the plurality of laser beams are adjusted so that the exposure width (scanning range) is (only Y is shown). When this optical device is attached to the main body of the image forming apparatus, the optical device is fixed somewhere between the position shown by the solid line and the position shown by the chain line.

If it is installed at the position shown by the solid line, the scanning range of each laser beam will be adjusted with a jig), but if it is fixed at a position tilted in the opposite direction to the solid line position, as shown by the chain line, The scanning range of the two laser beams at both ends is indicated by e in the figure.
This results in a shift in the main scanning direction by an amount indicated by . e is (C + C,) X day. The tolerance of the reference hole and pin is H
7. Assuming the F7 tolerance x, the maximum gap is considered to be about 50 μm, and the inclination C+C2 between the reference pins is about O,inn.

- Large cannot be made very small due to space constraints, etc., so in the end e cannot be made very small from about O, lao. A deviation of 0.1 degrees will appear as a color shift in the output image, degrading the image quality.

Furthermore, in the case of a clearance fit, there is a gap between the reference pin and the reference hole, so the optical device may vibrate relative to the image forming device. In particular, if the optical device is fixed to the main body via a spring or the like to prevent thermal expansion, if the writing optical device vibrates during 0 image writing where vibration is likely to occur,
The exposure position relative to the photoreceptor changes, causing unevenness in density called jitter in the image, leading to a reduction in image quality.

The present invention to be solved eliminates the above-mentioned drawbacks of the conventional positioning and mounting device of the laser writing optical device of the color image forming apparatus having the above-mentioned configuration. The positioning and mounting of optical devices does not hinder the work efficiency of replacing and assembling optical devices, and there is no gap between the reference pin and reference hole, and there is no variation in the fixed position, preventing one color shift or jitter. The task is to provide equipment.

In order to solve the above-mentioned problems, the positioning and mounting device of the present invention provides a tapered portion in the part of the reference pin that fits into the reference hole on the writing optical device side, and The present invention is characterized in that a taper portion is provided which has the same taper as the taper portion of the reference pin described above and which engages in pressure contact with the taper portion of the reference bottle when coupled.

Since the structure is configured as described above, when the reference pin starts to be inserted into the reference hole on the optical device side, there is a gap between the tapered part of the reference pin and the tapered part of the reference hole, which is difficult to replace or assemble. The necessary gap is formed, and the reference pin can be easily inserted into the reference hole, and as it is inserted, the tapered part of the reference pin naturally follows the tapered part of the reference hole, and the reference pin is positioned with high precision. The optical device is fixed to the image forming apparatus main body by screwing the tip into the threaded portion of the reference hole on the apparatus main body side and tightening it.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Below, embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 3(a) and 3(b) are a plan view and a side sectional view of a writing optical device mounting device according to a first embodiment of the present invention. The mounting stay 37 is provided with a reference hole in which a reference hole portion 37a and a threaded portion 37b are coaxially provided. On the other hand, the reference-side mounting portion 31 of the optical device 12 is provided with a tapered hole 32 that widens at the top, and the sub-reference mounting portion 33 is provided with a tapered oblong hole 34 . Both holes are provided with a straight portion having a certain length below the tapered portion and connected to the periphery of the lower end of the taper.

The reference pin 36, which is fitted into the reference hole of the stay 37 and the reference hole on the optical device side to fasten the optical device 12 to the image forming apparatus, has a tapered portion 36a that widens at the top and has the same taper as the tapered portion of the reference hole. A straight reference pin portion 36b and a threaded portion 36c are coaxially provided, and the reference pin 36 is inserted into the optical device side reference hole 32.34 from above, and the lower end threaded portion 36c is inserted into the stay side reference hole. The reference pin 36 is screwed into the threaded hole 37b at the lower part of the reference pin 36, and the screwdriver is engaged with the slotted groove at the top and tightened.
The tapered portion 36a is positioned and fixed in close contact with the tapered portion of the reference hole 32, 34 on the optical device side. In this way, there is no gap between the reference bottle and the reference hole, so if you adjust the scanning range of each laser beam before installing the optical device, you can readjust it while it is installed on the device main body. Even without it, color shift will not occur.

Further, since there is no gap between the reference pin and the reference hole, vibration of the optical device is prevented, and jitter caused by vibration during writing can be prevented.

FIG. 4 is a side sectional view of a second embodiment of the present invention. This embodiment is a fixing means that takes into account the thermal expansion of the writing optical device, and the reference pin 36 has a tapered portion 3 that widens as it goes downward.
6a, a straight reference bottle portion 36b is provided at the bottom thereof, and a threaded portion is provided above the tapered portion. The straight reference pin portion 36b is press-fitted into a reference hole 37a provided in the stay 37 and fixed. A tapered hole 32.34 that widens at the bottom is bored in the mounting portion 31.33 on the writing optical device 12 side. In this case as well, the reference hole 34 on the secondary reference side is an oblong tapered hole.

When the tapered reference hole 32.34 on the optical device 12 side is fitted onto the tapered reference bottle 36 and lowered, the tapered portion of the reference hole 32.34 becomes the tapered portion 36 of the reference pin.
The writing optical system 12 is positioned at a predetermined position as shown in a. By placing the nut 38 over the threaded portion at the upper end of the reference pin 36 and tightening it, the tapered portion 36a of the reference pin and the tapered portion of the reference hole are brought into pressure contact, eliminating any gap and positioning and fixing with high accuracy. A compression spring 38 is interposed between the nut 36 hooked onto the threaded portion of the reference pin 36 on the secondary reference side and the upper surface of the optical device mounting portion 33, and a tapered surface is provided to prevent expansion and contraction of the optical device 12 due to thermal expansion. It is possible to slip and miss.

As described above, according to the present invention, when the writing optical device is attached to the main body of the image forming apparatus, vibration is generated because there is no gap between the reference pin and the reference hole for positioning and mounting. This prevents the occurrence of jitter, and even when the writing optical device is removed for maintenance etc., it is accurately positioned at the specified position, there is no need to readjust the exposure scanning range, and the color Misalignment can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing a schematic configuration of an example of a color image forming apparatus to which the present invention is applied, and FIGS. 3(a) and 3(b) are a top view and a side sectional view of the first embodiment of the present invention, and FIG. 4 is a side sectional view of the second embodiment of the present invention. It is. Second prisoner (a) 12...Writing optical device 14Y, 14M, 14c, 14BK...Photosensitive drum (latent image carrier) 31.33...Writing optical device side mounting portion 32.34.・
・Reference hole 36...Reference pin 36a...Tapered part 36b...Reference pin part (b) 1st

Claims (1)

[Claims] A plurality of latent image carriers are optically scanned with polarized light beams emitted from exit ports provided at different positions of a single writing optical device casing and extending in the main scanning direction. Write the image,
The toner images of different colors obtained by developing the latent images formed on each latent image carrier are aligned and superimposed and transferred onto transfer paper that is conveyed in sequential contact with each latent image carrier. An apparatus for attaching a writing optical device to an apparatus main body of an image forming apparatus, the apparatus comprising:
The reference pins, which are fitted without gaps into the reference holes provided in at least two locations on the image forming apparatus main body side mounting portion, are fitted with the reference holes provided on the writing optical device side mounting portion, and fixed. In a mounting device for positioning and attaching a writing optical device to a predetermined position of an image forming apparatus, a tapered portion is provided in the portion of the reference pin that fits into a reference hole on the writing optical device side, and a tapered portion is provided in a portion of the reference pin that fits into a reference hole on the writing optical device side. A mounting device comprising: a tapered portion having the same taper as the tapered portion of the reference pin described above, and which engages in pressure contact with the tapered portion of the reference pin when coupled.