JPH0980851A - Color image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix an optical system for an image exposure to a focusing position, without requiring an adjusting mechanism and an attaching member. SOLUTION: This color image forming device adopts a supporting member 20 which holds an exposure optical system 12, to make a position adjustable and is for attaching the exposure optical system 12 and an adjusting device for supporting a CCD on which an image is formed by the focus of the exposure optical system 12. Further, an irreducibly minimum gap considering the solid difference between the members, a deviation in adjustment, etc., is previously provided between the exposure optical system 12 and the supporting member 20 and coated/filled with a low shrinkable adhesive whose shrinkage factor (volume) is <=10%, to fix the exposure optical system 12 and the supporting member 20 by the hardening of the adhesive, after the focusing position of the exposure optical system 12 is set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image forming apparatus for forming a color image by superposing a plurality of toner images on the peripheral surface of an image forming body, and more particularly to an optical system as an image exposing means and a light source. The present invention relates to a digital type color image forming apparatus using an integrated exposure optical system.

[0002]

2. Description of the Related Art As a method for forming a multicolor image, a monochromatic toner image formed on each photoconductor is intermediately transferred by equipping the photoconductor with the same number of images as necessary, a charger and a developing device. A device that creates a color image by overlaying it on the body (A)
Or a device (B) for forming a color image by repeating charging, image exposure and development for each color by rotating one photoconductor a plurality of times, or similarly, charging and image for each color within one rotation of one photoconductor. There is known an apparatus (C) for forming a color image by sequentially performing exposure and development.

However, the above-mentioned device (A) has a drawback that the volume of the device is increased because a plurality of photoconductors and intermediate transfer members are required, while the device (B) has a charging means, an image exposing means and a photoconductor. However, there is a restriction that the size of an image to be formed is limited to the surface area of the photoconductor or less, although the volume is reduced, and in that point, the device (C) has one photoconductor. However, there are many advantages in that there is no restriction on the size of the image and high-speed printing is possible.

[0004]

However, in the apparatus (C) described above, the optical system is set with high accuracy so that all of the plurality of image exposure means are accurately connected to the surface of the photoconductor, and the registration accuracy of the image exposure is improved. It is necessary that the image exposure position of the image exposure to be superposed is always correctly synchronized with the image plane.

As a result of solving and improving this point, the present invention provides
It is an object of the present invention to provide a color image forming apparatus capable of adjusting and fixing the image exposure means to the surface of the photoconductor with high precision and easy work.

[0006]

The above-mentioned object is to form a plurality of toner images on the image forming body by superposing a plurality of toner images on the image forming body by repeating charging, image exposure and development during one rotation of the drum-shaped image forming body. In a color image forming apparatus for collectively transferring the formed multicolor toner images onto a transfer material, the image exposing means sets a focal position by an adjusting device, and then, on a supporting member via a low-curing shrinkable adhesive. A color image forming apparatus (invention according to claim 1), and a plurality of image forming bodies that are repeatedly charged, image-exposed and developed during one rotation of the drum-shaped image forming body. In the color image forming apparatus, in which the formed toner images are superposed on each other and then the formed multicolor toner images are collectively transferred onto the transfer material, the image exposing means has at least focal positions for the plurality of two-dimensional CCDs. Three A color image forming apparatus (invention according to claim 2) characterized in that the focus position is predicted and set by measuring the half-width or the maximum brightness after the above change, and a drum-shaped image forming body. Electrified during one rotation,
In the color image forming apparatus, in which a plurality of toner images are superimposed and formed on the image forming body by repeating image exposure and development, and then the formed multicolor toner images are collectively transferred to a transfer material. The means is supported by a sticking member that is transparent to ultraviolet rays, and is fixed on the supporting member via an adhesive agent that is ultraviolet curable (the invention according to claim 4).

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to the description of each embodiment, the structure and operation of a common color image forming apparatus will be described with reference to FIGS.

Although FIG. 1 shows a color image forming apparatus provided with a so-called internal type image exposing means for accommodating the image exposing means inside the image forming body, the present invention places the image exposing means outside the image forming body. The present invention is also applied to a color image forming apparatus of the arrangement type.

Reference numeral 10 denotes a drum-shaped image forming body, that is, a photosensitive drum, which is formed by coating an organic photosensitive layer (OPC) composed of a transparent conductive layer on a basic outer periphery formed by a transparent member such as optical glass or transparent acrylic resin. Then, it is rotated clockwise while being grounded.

Reference numeral 11 denotes a scorotron charger, which is a charging means. The scorotron charger 11 performs a charging operation on the above-described organic photosensitive layer of the photosensitive drum 10 by a grid held at a predetermined potential and a corona discharge by a discharge wire. A uniform electric potential is applied to the drum 10.

Reference numeral 12 denotes an exposure optical system which is an image exposure means, and includes LEDs, FL, E arranged in the axial direction of the photosensitive drum 10.
It is composed of light emitting elements such as L and PL and a Selfoc lens. The image signals of the respective colors read by the separate image reading device are sequentially taken out from the memory and input as electric signals to the respective exposure optical systems 12.
The emission wavelength of the light emitting device used in this example is from 500 to
It is in the range of 900 nm.

Each of the exposure optical systems 12 is mounted on a columnar support member 20 and housed inside the base of the photosensitive drum 10. The exposure optical system 12 may be composed of a combination of an optical shutter member such as LCD, LISA, PLZT and the like, and an image forming lens such as a SELFOC lens, in addition to the above light emitting element.

Reference numerals 13Y, 13M, 13C and 13K denote developing units which are developing means for containing yellow (Y), magenta (M), cyan (C) and black (K) developers, respectively.
The developing sleeves 130 rotate in the same direction while maintaining a predetermined gap with respect to the peripheral surface of the photoconductor drum 10.

Each of the developing devices 13 is the charging device 1 described above.
The electrostatic latent image formed on the photosensitive drum 10 by the charging by 1 and the image exposure by the exposure optical system 12 is reversely developed in a non-contact state by applying a developing bias voltage.

Next, the process of the color image forming apparatus in this apparatus will be described.

The original image is temporarily read as an image signal for each color of Y, M, C and K from an image read by an image pickup device or an image edited by a computer in an image reading apparatus separate from this apparatus. Stored and stored in memory.

When the image recording is started, the photoconductor drive motor is rotated to rotate the photoconductor drum 10 clockwise.
At the same time, the application of a potential to the photosensitive drum 10 is started by the charging action of the charger 11 (Y).

After a potential is applied to the photosensitive drum 10, the exposure optical system 12 (Y) starts image exposure with an electric signal corresponding to the first color signal, that is, the image signal of yellow (Y), and the drum is started. An electrostatic latent image corresponding to the yellow (Y) image of the original image is formed on the photosensitive layer on the surface by the rotational scanning of.

The latent image is reversal-developed by the developing device 13 (Y) with the developer on the developing sleeve in a non-contact state, and a yellow (Y) toner image is formed according to the rotation of the photosensitive drum 10.

Next, the photoconductor drum 10 is given a potential on the yellow (Y) toner image by the charging action of the charger 11 (M), and the second color signal of the exposure optical system 12 (M), that is, Image exposure is performed by an electric signal corresponding to the magenta (M) image signal, and non-contact reversal development by the developing device 13 (M) causes the magenta (M) toner on the yellow (Y) toner image. The images are sequentially superimposed and formed.

By the same process, the charger 11 (C),
The cyan (C) toner image corresponding to the third color signal is further generated by the exposure optical system 12 (C) and the developing device 13 (C), and finally, the charger 11 (K) and the exposure optical system 12 are used.
(K) and the developing device 13 (K) sequentially form a black (K) toner image corresponding to the fourth color signal, and the color image is formed on the peripheral surface of the photosensitive drum 10 within one rotation. A toner image is formed.

The color toner image thus formed on the peripheral surface of the photosensitive drum 10 is a transfer material which is conveyed from the paper feed cassette 15 in the transfer device 14A and is fed in synchronization with the driving of the timing roller 16. It is transferred to transfer paper.

The transfer paper on which the toner image has been transferred is removed from the charge by the static eliminator 14B and separated from the peripheral surface of the drum. Will be ejected onto the tray.

On the other hand, the photosensitive drum 10 from which the transfer paper is separated
The cleaning device 19 removes and cleans residual toner to continue forming the toner image of the original image, or temporarily stops and waits for formation of a new toner image of the original image.

As shown in FIG. 2, the photosensitive drum 10 has flange members 10A and 10B at both ends for engaging and fixing the photosensitive drum 10, which are directly or indirectly borne by a drum shaft 110 which is erected and fixed to the main body of the apparatus. A gear G, which is rotatably supported and is integral with the flange member 10B, is engaged with a drive gear on the apparatus main body side and driven to rotate in a predetermined direction.

The drum shaft 110 is the photosensitive drum 1
The support member 20 for mounting and fixing each of the above-described exposure optical systems 12 is inserted into the inside of 0 and fixed integrally.

FIG. 3 shows a color image forming apparatus of another embodiment, in which an exposure optical system 12 is provided outside the photosensitive drum 10.
The configuration in which is arranged is shown. The photoconductor drum 10 described above.
As described above with reference to FIG. 2, the flange members 10A and 10B at both ends for engaging and fixing the same are rotatably supported by being directly or indirectly supported by the drum shaft 110 which is erected and fixed to the apparatus main body. The gear G, which is integral with the flange member 10B, is rotated in a predetermined direction by being driven by meshing with a drive gear on the apparatus body side.

FIG. 4 shows the exposure optical system 1 of the embodiment shown in FIG.
2 shows a single component of the support member 40 that holds 2. The supporting member 40 is a cylindrical member that encloses the photosensitive drum 10 and is concentric with the photosensitive drum. Each exposure optical system 12 is fixed to the peripheral surface of the supporting member 40. Support member 4 shown in FIG.
The slit hole opened at 0 is provided for inserting each developing device 13 and each exposure optical system 12.

Each of the inventions described below relates to a method of mounting and fixing each exposure optical system 12 to the support member 20 or the support member 40.

An adjusting device 100 as shown in FIG. 5A is used to set the mounting position of each exposure optical system 12 with respect to each supporting member 20 in the color image forming apparatus shown in FIG.

The adjusting device 100 includes a fine movement stage 110 that clamps and holds the exposure optical system 12, a slide table 120 that supports a CCD and moves in parallel along a linear scale,
Rotation angle setting means 1 provided with a rotary encoder that supports the support member 20 and rotates it by a required degree to set the position of the mounting surface.
The image forming surface of the CCD, which is composed of 30 and 30, is moved parallel to the axis of the supporting member 20 while being accurately set at a position corresponding to the photosensitive surface of the photosensitive drum 10. It has become.

The fine movement stage 110 has the exposure optical system 12 held by fine adjustment of the horizontal and vertical angles.
After adjusting the angle and position of the exposure optical system 12 with respect to the CCD surface, the exposure optical system 12 is finely moved in the direction perpendicular to the CCD surface to expose the exposure optical system 1 as shown in a sectional view (FIG. 5B).
The focal point of 2 is focused on the CCD surface, and the relative positional relationship of the exposure optical system 12 with respect to the support member 20 is adjusted. The focus position of the entire exposure optical system 12 with respect to the CCD surface is adjusted by moving the slide base 120 in parallel at two positions near at least both ends of the exposure optical system 12.

On the other hand, in the case of the color image forming apparatus shown in FIG. 3 in which the exposure optical system 12 is arranged outside the photosensitive drum 10, the exposure optical system is utilized by utilizing the notch portion of the supporting member 40 as shown in FIG. A fine movement stage 110 capable of holding 12 inside the support member 40, a slide base 120 capable of moving parallel to the axis of the photosensitive drum (the axis of the support member 40) inside the support member 40, and the support member. A rotation angle setting means (not shown) including an encoder that supports 40 and rotates a required angle to set the position of the mounting surface is used. Also in this case, the focus of the exposure optical system 12 is set to the CCD as in the case described with reference to FIG.
Focusing on the surface, the relative positional relationship of the exposure optical system 12 with respect to the support member 40 is adjusted.

(Embodiment 1) An embodiment of the invention according to claim 1 will be described with reference to FIG.

Each exposure optical system 12 includes the adjusting device 10 described above.
After adjusting the position with respect to the CCD by 0, it is attached and fixed to the supporting member 20 via an adhesive.

The gap between the back surface of the exposure optical system 12 and the mounting surface of the support member 20 which is set in advance includes individual differences including variations in the focal length of the exposure optical system 12, an adjustment error when setting the focus position, or the support member. In consideration of the manufacturing error of 20 itself, the minimum gap including the application amount of the adhesive is set, and the adhesive is applied and filled in the gap.

As the above-mentioned adhesive, an adhesive having a shrinkage rate (volume) of 10% or less, such as a UV-curable modified acrylic resin-based adhesive or epoxy resin-based adhesive, which has a low shrinkage upon curing and has a low curing shrinkage. Is used. Generally, by increasing the dimensional accuracy of the related parts, the amount of gap required for adjustment is reduced, and it is sufficient to set the amount of the gap to 0.5 mm at the maximum. The accompanying variation in the exposure optical system 12 is at most 0.
It will be within 02 mm or less, and it can be stopped within the amount of deviation of the in-focus position allowed in the fixed state.

Therefore, according to the present invention, the exposure optical system 1
2 is highly accurately fixed to a predetermined position of the support member 20 only by an adhesive, and as a result, a fine adjustment mechanism for supporting the exposure optical system which has been conventionally used and a fixing device for fixing the exposure optical system to the support member. Since the screw members and so on are not required, the cost can be reduced by simplifying the mechanism and reducing the labor.

(Embodiment 2) An embodiment of the invention according to claim 2 will be described with reference to FIG.

According to the present invention, the focus position of the image exposure means, which has been conventionally adjusted visually, can be automatically adjusted.

The optical characteristics of the exposure optical system 12 are investigated in advance, and the change in the half-value width or the maximum luminance as shown in FIG. The following approximate expression is programmed and stored in the focus position adjusting memory. FIG.
As is clear from the above, the half value width is the minimum value and the maximum brightness is the maximum value at the in-focus position.

On the other hand, the slide base 120 of the adjusting device 100 described above.
The CCD supported by is a two-dimensional area type CCD, and the above CCDs are installed at two locations on the linear scale so as to correspond to the vicinity of both ends of the exposure optical system 12 set at a predetermined position in the main scanning direction. To be done.

When adjusting the position of the exposure optical system 12 to the in-focus position, the full width at half maximum or the maximum brightness is measured before and after the inferred in-focus position and at least three points, and the measurement is performed. The values are plotted (substituted) on the above program (an approximate expression of a quaternary expression or less) to perform the calculation processing of the focus position, and the exposure optical system 12 is automatically moved to the CCD by an amount based on the calculation result. The position of the exposure optical system 12 is controlled, and the position of the exposure optical system 12 is set with the stop position of the exposure optical system 12 as the in-focus position. In Figure 8, the black circle is 3
The measurement points are indicated by X, and X indicates the in-focus position obtained by the arithmetic processing.

Further, by using the two-dimensional CCD, it is possible to automatically set the position of the exposure optical system 12 in the main scanning and sub scanning directions by providing a mounting reference position on the CCD, and the focus position is adjusted. It is possible to completely automate the position setting of the exposure optical system 12 by automatically and sequentially performing the position setting in the main scanning / sub scanning direction after the setting.

(Embodiment 3) An embodiment of the invention according to claim 4 will be described with reference to FIG.

Each exposure optical system 12 corresponds to the adjusting device 10 described above.
After determining the position with respect to the CCD by 0, the supporting member 2
A pair of sticking members are interposed between the sticking member and 0, and the sticking member is stuck and fixed via an adhesive.

The above-mentioned adhesive member is made of a material that transmits ultraviolet rays efficiently, and an ultraviolet-curable adhesive agent is used as the adhesive agent.

The exposure optical system 12 shown in FIG. 9 (a) has the adhesive members 120A provided at both ends thereof integrated with each other, and the adhesive applied and filled between the adhesive member 12A and the mounting surface of the supporting member 20. Is cured and fixed by irradiation with ultraviolet rays that pass through the adhesive member 120A.

The exposure optical system 12 shown in FIG.
It is adapted to be attached to the attachment surface of the support member 20 via the letter-shaped attachment member 120B. Application and filling between the attachment member 120B and the exposure optical system 12, and between the attachment member 120B and the attachment surface of the support member 20. The ultraviolet curable adhesive thus obtained is cured and fixed by irradiation of ultraviolet rays which are dispersed and transmitted through the coating member 120B.

Further, the exposure optical system 12 shown in FIG. 9C is provided with a supporting member 20 via a wedge-shaped attaching member 120C for adjustment.
Can be attached to the attachment surface of the attachment member 12
The adhesive applied and filled between 0C and the mounting surface of the support member 20, between the sticking member 120C and the exposure optical system 12 is cured and fixed by irradiation with ultraviolet rays that pass through the sticking member 120C and are reflected by the inner surface.

Therefore, the work of adhering each exposure optical system to the support member shown in FIGS. 9A to 9C is extremely easily and efficiently performed in a bright room, and ultraviolet rays are irradiated at the time of adjustment. Immediately, the exposure optical system 12 can be accurately fixed to the adjusted position.

[0052]

According to the present invention, a plurality of image exposing means can be fixed accurately and firmly at a predetermined position with respect to the surface of the photoconductor by shortening the adjusting time without incorporating an adjusting mechanism or a fixing member in the apparatus. As a result, a color image forming apparatus which has a simple structure and can be expected to reduce the cost is realized.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram of an internal exposure type color image forming apparatus.

FIG. 2 is a cross-sectional view showing a support structure of an image exposure unit in the case of internal exposure.

FIG. 3 is a cross-sectional configuration diagram of an external exposure type color image forming apparatus.

FIG. 4 is a perspective view of a support member of an image exposure unit used for external exposure.

5A and 5B are a perspective view and a cross-sectional view of an essential part showing a configuration of an adjusting device.

FIG. 6 is an explanatory view showing a mounting form on a support member used for external exposure.

FIG. 7 is an explanatory view showing a method of directly fixing the image exposure means with an adhesive.

FIG. 8 is a graph of an approximate expression used for predicting a focus position of the image exposure unit.

FIG. 9 is an explanatory view showing an indirect fixing method of the image exposure means via a sticking member.

[Explanation of symbols]

 10 Photosensitive Drum 11 Charging Device 12 Exposure Optical System 13 Developing Device 14A Transfer Device 14B Electrifying Device 15 Paper Feed Cassette 16 Timing Roller 17 Fixing Device 19 Cleaning Device 20, 40 Supporting Member 100 Adjusting Device 110 Fine Movement Stage 120 Sliding Base 130 Rotation Angle setting means 120A, 120B, 120C Sticking member

Front page continuation (72) Inventor Satoshi Haneda 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Stock Company (72) Inventor Toshihide Miura 5-14-14 Midori-cho, Koganei-shi, Tokyo

Claims (6)

[Claims] 1. A charge is made during one rotation of a drum-shaped image forming body,
In the color image forming apparatus, in which a plurality of toner images are superimposed and formed on the image forming body by repeating image exposure and development, and then the formed multicolor toner images are collectively transferred to a transfer material. The color image forming apparatus is characterized in that the means is fixed on the supporting member via an adhesive having a low curing shrinkage after the focal position is set by the adjusting device. 2. The charging during one rotation of the drum-shaped image forming body,
In the color image forming apparatus, in which a plurality of toner images are superimposed and formed on the image forming body by repeating image exposure and development, and then the formed multicolor toner images are collectively transferred to a transfer material. The color image forming apparatus is characterized in that the means changes the focus position for each of the plurality of two-dimensional CCDs at least at three or more places and predicts and sets the focus position by measuring the half-value width or maximum brightness. 3. The color image forming apparatus according to claim 2, wherein the setting of the focus position, the main scanning and the sub-scanning direction are sequentially performed. 4. The charging is performed during one rotation of the drum-shaped image forming body,
In the color image forming apparatus, in which a plurality of toner images are superimposed and formed on the image forming body by repeating image exposure and development, and then the formed multicolor toner images are collectively transferred to a transfer material. The color image forming apparatus is characterized in that the means is supported by a sticking member that is transparent to ultraviolet rays, and is fixed on the supporting member via an ultraviolet curable adhesive. 5. The color image forming apparatus according to claim 4, wherein the sticking member is provided at a site that can be irradiated with ultraviolet rays. 6. The color image forming apparatus according to claim 4, wherein the supporting member has an adhesive surface of the pasting member as an ultraviolet reflecting surface.