JPH06301262A - Color electrophotographic device - Google Patents

Abstract

PURPOSE:To provide a compact and lightweight desk top type color electrophotographic device capable of maintenance of a photosensitive, body, etc., by a user and color matching with high accuracy of <=100mum and has excellent handleability. CONSTITUTION:Four color developing units 50, 52, 54 and 56 are horizontally installed and one endless belt-like photosensitive body 14 is arranged in a roughly elliptic shape in the lower side of the developing units and brought into contact with a transfer body 40 on the end surface of the length side of the photosensitive body 14, to transfer each color toner image. Moreover, the photosensitive body 14 is a cartridge type, to make the maintenance by the user easy and constituted to execute positioning with respect to a device main body with high accuracy. Pulleys 10-12 on which the photosensitive body 14 is extended have the same diameter and simultaneously, the diameter of the transfer body 40 is the integral multiple of that of the pulley, to reduce the influence of the eccentricity of the pulley, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color electrophotographic apparatus, and more particularly to a desktop type small laser printer.

[0002]

2. Description of the Related Art The life of a photoconductor is shorter than the life of the device, and it is necessary to replace the photoconductor until the life of the device is reached. In the market of small laser printers, maintenance such as photoconductor replacement is required to be performed by the user, and the photoconductor must be realized by a cartridge configuration that can be easily attached and detached by the user.

On the other hand, highly accurate color matching is an essential specification for a color electrophotographic apparatus. The required color matching accuracy is approximately 100 μm or less, and in order to realize this accuracy, the average accuracy needs to be 60 μm or less.

An apparatus satisfying both the convenience of market needs and the basic specifications of color electrophotography has not been realized so far.

A conventional device is, for example, Japanese Patent Laid-Open No. 3-1.
As described in JP-A-06736, the photosensitive drums are arranged in a row in the lateral direction for each of the four colors, and an endless intermediate transfer belt is provided so as to contact the lower portion of the photosensitive drums.

Further, as disclosed in Japanese Unexamined Patent Publication No. 4-326373, developing means for four colors is installed side by side below one photosensitive member in the form of an endless belt, and four color developing means are arranged on the photosensitive member. The toner images are superposed.

[0007]

In the apparatus disclosed in Japanese Unexamined Patent Publication (Kokai) No. 3-106736, the developing process for each color on the photoconductor is equivalent to that for a single color, and the toner image is transferred to the intermediate transfer body. Since they are superimposed on each other, there is no deterioration in print quality and the structure is suitable for high image quality, but it is difficult to reduce the size and weight due to the complicated structure.

On the other hand, the apparatus disclosed in Japanese Unexamined Patent Publication No. 4-326373 has the advantages that the structure is simple and the size and weight can be reduced. However, since the respective colors are superposed on the photoconductor, The deterioration of the printing quality causes the deterioration of the performance of exposure and development due to the superposition of the toner images, which deteriorates the printing quality and is not suitable for high image quality.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems, and to provide a small-sized, lightweight, high-quality color electrophotographic apparatus with high-precision color matching that enables user maintenance.

[0010]

In order to achieve the above object, a structure in which toner images of respective colors are once superposed on an intermediate transfer member to achieve high image quality is provided above a single endless belt-shaped photosensitive member. The four-color phenomenon means were arranged side by side, and the toner images of the respective colors on the photoconductor were transferred by contacting with the transfer body on the major axis side of the photoconductor which was formed into a substantially elliptical shape.

Further, the photosensitive member is a cartridge type so that the user can easily perform maintenance, and even if the user replaces the photosensitive member, the apparatus main body and the photosensitive member cartridge can be positioned with high accuracy.

Specific embodiments of the color electrophotographic apparatus of the present invention are as follows.

An endless belt-shaped photosensitive member on which an electrostatic latent image is formed by exposure, developing means for forming a toner image on the electrostatic latent image formed on the photosensitive member, and a toner by contacting a part of the photosensitive member. In a color electrophotographic apparatus provided with a transfer body to which an image is transferred, a plurality of developing means are arranged in a row in a row, and a single endless belt-shaped photoreceptor is provided to be in contact with these developing means.

Further, an endless belt-shaped photosensitive member on which an electrostatic latent image is formed by exposure, developing means for forming a toner image on the electrostatic latent image formed on the photosensitive member, and a portion of the photosensitive member are brought into contact with each other. In a color electrophotographic apparatus provided with a transfer body to which a toner image is transferred, a plurality of developing means are arranged in a row in a row, and one endless belt shape is provided below the plurality of developing means so as to contact each developing means. The photoconductor of No. 1 was passed horizontally so as to have a substantially elliptical shape, and the endless belt and the transfer member were arranged side by side so that the end surface of the endless belt on the major axis side was in contact with the transfer member.

In the above structure, the developing means may be provided for four colors. Further, the endless belt-shaped photosensitive member may be constructed by being stretched over three or more pulleys. Further, a cartridge in which an endless belt-shaped photoconductor is bridged over three or more pulleys is provided, and the cartridge can be easily attached to and detached from the color electrophotographic apparatus from a direction parallel to a plane substantially parallel to the arrangement direction of the developing device. You may.

In addition, an endless belt-shaped photoconductor is laid over 3
One of the above pulleys, except for the pulley that supports the drive pulley for driving the endless belt-shaped photoconductor with sufficient rigidity and freely rotatably supported by the device, and that applies the tension to the endless belt-shaped photoconductor. The pulley may be rotatably supported in the device in a two-dimensional direction.

Further, the drive pulley and the pulley rotatably supported in the two-dimensional direction on the apparatus may be provided with load means for applying pressure from the apparatus in the axial direction of both pulleys or in the axial direction of either one of the pulleys. . The load means may be a leaf spring provided in a pulley mounting portion provided on the device side.

The surfaces of all the pulleys that apply tension to the endless belt-shaped photoreceptor may be covered with a material softer than the base material of the endless belt, and the material may be rubber.
A rubber layer is provided on the surface of the drive pulley, and its thickness is 2 m.
It may be m or less.

Further, another embodiment of the color electrophotographic apparatus of the present invention is as follows.

An endless belt-shaped photosensitive member on which an electrostatic latent image is formed by exposure, developing means for forming a toner image on the electrostatic latent image formed on the photosensitive member, and a toner by contacting a part of the photosensitive member. In a color electrophotographic apparatus provided with a transfer body on which an image is transferred, a single endless belt-shaped photoconductor which is passed in a laterally long shape so as to have a substantially elliptical shape and brought into contact with a developing means, and an endless belt-shaped photoconductor. The endless belt and the transfer member are arranged side by side so that the end surface on the major axis side of the body is in contact with the transfer member, and the endless belt-shaped photosensitive member is a structure in which the endless belt-shaped photosensitive member is bridged over three or more pulleys. All the pulleys except the pulley that applies tension to the photoconductor have the same outer diameter dimension, and are configured to have an integer ratio with an accuracy of 0.5% or less with respect to the outer diameter dimension of the transfer member.

In this structure, a plurality of developing means are provided,
It is also possible to arrange the plurality of developing units in a horizontal row and to dispose a single endless belt-shaped photosensitive member below the plurality of developing units.

As still another mode, the color electrophotographic apparatus having the above-mentioned structure is provided with three legs for installation on a desk on the bottom surface. Further, the height of the device body is set to 370 mm or less.
Furthermore, the weight of the device was set to 50 kg or less.

[0023]

When each color toner image on the photoconductor is transferred onto the transfer body one by one, the positioning accuracy between the photoconductor and the transfer body is required to be 50 μm or less after the entire apparatus is assembled. In addition, even after the user attaches and detaches the photoconductor cartridge, the accuracy after mounting must be always maintained.

Further, since the main body of the apparatus is manufactured to be small and lightweight and at low cost, the flatness of the desk on which it is installed causes
Bending, twisting, or the like, which exceeds the required color matching accuracy, may occur. This is unavoidable for user maintenance products.

When the above-mentioned means is used, when the photoconductor cartridge is mounted, it can be positioned by urging the photoconductor cartridge to a designated position with a constant pressure, and the pulley that bridges the photoconductor has the same diameter. In addition, the influence of eccentricity of the pulley is reduced by making the diameter of the transfer body an integral multiple of the pulley diameter.

Further, the positioning of the photoconductor cartridge is performed at the minimum necessary portion, that is, at the drive pulley which directly receives the external force and at another point, so that even if the mechanical precision of the photoconductor cartridge is insufficient, the precision of the main body of the apparatus is imitated. It is configured.

Further, even if the main body of the apparatus is distorted due to user maintenance, the bottom surface of the apparatus can always be kept flat by installing it on a desk with three legs, and the distortion of the apparatus can be suppressed.

By these actions, the developing means for four colors are arranged in a horizontal row, and one endless belt-shaped photoconductor is provided to be in contact with these developing means, and the long diameter side of the endless belt comes into contact with the transfer body. As described above, a structure in which an endless belt and a cylindrical transfer member are arranged side by side can be adopted, and a disc top type color electrophotographic apparatus capable of highly accurate color matching has been realized.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

One embodiment of the present invention is shown in FIG. FIG. 1 shows a desktop type color electrophotographic apparatus 1 according to the present invention installed on a desk. Desk 100 placed indoors
Above, the front foot 101, the rear foot 103 and the front foot 10 provided on the bottom plate
The apparatus main body 1 is installed with the foot 102 not shown by the shadow of 1.

An endless belt-shaped photoconductor 14 on which an electrostatic latent image is formed by laser light emitted from the exposure device 2 in the direction of the arrow, and a toner image is formed on the electrostatic latent image formed on the photoconductor. A yellow developing device 50, a magenta developing device 52, a cyan developing device 54, and a black developing device 56 are arranged in a horizontal row, and are constituted by a cylindrical transfer drum 40 that contacts a part of the photoconductor 14 and a toner image is transferred. It

The developing devices arranged in a horizontal row are arranged above,
As shown in the figure, the photoconductor 14 is horizontally extended so as to come into contact with each of the developing devices so as to have a substantially elliptical shape.

The photoconductor 14 is composed of a removable cartridge 3 which is bridged over four pulleys. The pulley includes a drive pulley 10 for driving the photoconductor 14, a pulley A11 for limiting the exposure position, a pulley B12 for ensuring a contact width between the transfer drum 40 and the photoconductor 14, and a photoconductor 14. It is composed of a tension pulley 13 for applying an initial tension. Each pulley is rotatably supported by the cartridge side plates 31, 31 '(see FIG. 2) of the cartridge 3.

Next, the developing procedure will be described. First, the charger A
The photosensitive member 14 is uniformly charged by 18, and the exposure device 2 irradiates the photosensitive member 14 with a laser beam in the direction of the arrow shown in the drawing to form a yellow electrostatic latent image.

A yellow toner image is formed on the yellow electrostatically attracted image by the yellow developing device 50, and the transfer drum 40
And is conveyed to the contact portion between the photosensitive member 14 and the photosensitive member 14. At this time, the magenta developing device 52, the cyan developing device 54, the black phenomenon device 56 and the photoconductor 14 are separated from each other. The yellow toner image is transferred to the transfer drum 40. After transfer, photoconductor 1
The yellow toner remaining on the No. 4 is the blade cleaner 17
To be cleaned.

Thereafter, magenta, cyan, and black toner images are superimposed on the transfer drum 40 by the same process to form a color toner image.

At the time of development, it is necessary to maintain the gap (for example, 0.4 mm) between the yellow mag roll 51, the magenta mag roll 53, the cyan mag roll 55, the black mag roll 57, and the photoconductor 14 with high accuracy, and especially the photosensitivity. It is difficult to maintain and manage the voids in the structure using the endless belt for the body 14. In order to maintain this gap with high accuracy, in the device of this embodiment, the gap between the yellow mag roll 51 and the photoconductor 14 is
Yellow Magroll 51 and its Yellow Magroll 51
The gap between the magenta mag roll 53, the cyan mag roll 55, and the photoconductor 14 is controlled by the drive pulley 10 that faces the magenta mag roll 53 and the cyan mag roll 55 via a belt. A16,
The gap between the black mag roll 57 and the photoconductor 14 was managed by the stay B15 by the black mag roll 57 and the tension pulley 13.

By managing the voids for each color in this way, high accuracy can be realized.

The sheets are deposited in the hopper 73 or prepared in the manual hopper 70. The paper in the hopper 73 is conveyed one by one by the paper feed roller 74 and guided by the paper feed guide 75. The sheet feeding state is monitored at the detection timing of the detection sensor A76. On the other hand, the sheet prepared in the manual feed hopper 70 is detected by the detection sensor B71, and the feeding roller 72 is driven to be conveyed to the sheet feeding roller 74.

The skew of the sheet is corrected by starting and stopping the registration roller 77 at the detection timing of the detection sensor A76.

The corrected sheet is pressed against the transfer drum 40 by the transfer roller 78, and the toner image formed on the transfer drum 40 is transferred onto the sheet. This toner image may be one color, multi-color, or full color depending on the type of color transferred to the paper.

The sheet on which the toner image has been transferred is guided by the transfer guide 79 and then to the fixing device 80. After the toner image is fixed on the sheet by the fixing device 80, the sheet is detected by the detection sensor C81 to monitor the sheet conveyance state. After that, the paper is discharged to the discharge tray 83 by the discharge roller 82.

After the toner image is transferred to the paper, the residual toner on the transfer drum 40 is cleaned by the cleaner 41, and the process for transferring the toner image from the next photosensitive member 14 onto the transfer drum 40 is started.

The cartridge 3 for holding the photoconductor 14 of the color electrophotographic apparatus 1 can be easily attached to and detached from the color electrophotographic apparatus 1 to enable the user maintenance shown in FIG.

The cartridge 3 has handles 24 and 24 'on both sides of the cartridge 3 for easy carrying by the user. Further, in order to easily mount the cartridge 3 on the color electrophotographic apparatus 1, the cartridge 3 is fixed to the cartridge holder 22 having the holder guide rail 25. In the cartridge holder 22,
A handle 23 is provided, and the cartridge 3 is attached to the color electrophotographic apparatus 1 shown in FIG. When the handle 23 is tilted downward after the cartridge 3 is mounted, the hooks 20 provided on both sides of the rotating shaft of the handle 23 are coupled to the pins 38 fixed to the side plate of the main body of the color electrophotographic apparatus 1 and the cartridge Holder 22
The cartridge 3 is fixed to the color electrophotographic apparatus 1 via the.

A gear 21 for transmitting a driving force is attached to one shaft end of the drive pulley 10. In this embodiment, the gear 2
Although a helical gear is used as the gear 1, other gears such as a spur gear may be used. The both ends of the tension pulley 13 are rotatably supported by links whose center of rotation is coaxial with the pulley B12. Then, this link is pulled by a spring 19 in a direction in which tension is applied to the photoconductor 14.

The tension pulley 13 has a portion abutting against the photoconductor slightly shorter than the width of the photoconductor 14 and has a taper at the end, and the photoconductor 14 is biased to both sides in the width direction of the photoconductor 14. The ribs (not shown) provided on the inner peripheral surface of the vehicle tilt on the shaft end portion of the tension pulley 13 to tilt. Due to this inclination, the deviation of the photoconductor 14 can be corrected by the movement loci of the photoconductor 14 and the tension pulley 13. At this time, a material 13 'for increasing the friction coefficient is coated between the photoconductor 14 and the tension pulley 13 so that slip does not act. In this example, rubber was used.

The space between the photoconductor 14 and each color mag roll is
Both ends of the stays A16 and B15 fixed to the cartridge side plates 31 and 31 'of the cartridge 3 are in contact with the gap rings provided in each color developing device so that they can be managed.

An example of mounting the cartridge 3 on the color electrophotographic apparatus 1 will be described with reference to FIG.

The cartridge 3 is fixed to the cartridge holder 22 by holding the handles 24 and 24 '. At this time, the protrusion 26 provided on the shaft end of the pulley A11 of the cartridge 3 and on the lower part of the center of the substantially oval cartridge 3 in the major axis direction.
Is fitted and fixed in the concave portions 28 and 29 provided on the end surface portion of the cartridge holder 22 in the mounting direction. Pulley A
Reference numeral 11 has a structure in which the shaft end portion can be rotated while being fitted in the concave portion 29. Further, an opening is provided on the bottom surface of the cartridge holder 22 so that the photoconductor 14 of the cartridge 3 can be irradiated with laser light from the exposure device 2.

Next, the cartridge holder 22 to which the cartridge 3 is fixed is inserted from the mounting opening on the front part of the color electrophotographic apparatus 1. The mounting opening is the cartridge cover 111.
It can be exposed and installed by opening. The guide rails 25, 25 'of the cartridge holder 22 are provided on the color electrophotographic apparatus 1 and the guide rails 3 on both sides in the mounting direction are provided.
Cartridge holder 2 while making contact with 9, 39 '
2 is inserted into the color electrophotographic apparatus 1, the cartridge 3 hits the stopper provided in the color electrophotographic apparatus 1, and when the cartridge 3 cannot be further inserted, the handle 23 is tilted,
The hook 20 is scratched and fixed to the pins 38, 38 '(see FIG. 4).

Yellow developing device 50, magenta developing device 5
2. In order to maintain the developing gap between the mag rolls of the cyan developing device 54 and the black developing device 56 and the photoconductor 14 with high accuracy, when the photoconductor 14 is attached to the color electrophotographic apparatus 1, the magenta image follows the stay B15. The structure is such that the cyan mag roll 55 follows the mag roll 53, the stay A16, the yellow mag roll 51 follows the drive pulley, and the black mag roll 57 follows the tension pulley 13 (see FIG. 2).

The manner in which the cartridge 3 is guided and mounted in the color electrophotographic apparatus 1 will be described in detail with reference to FIGS.

FIG. 4 shows the guiding means for the cartridge 3. The cartridge 3 is fixed to the cartridge holder 22, and the handle 23 is raised. At this time, as shown in the figure, the hook 20 is laterally oriented at the portion connected to the device side.

FIG. 4 shows only the parts necessary for fixing the cartridge 3 in the mounting portion of the color electrophotographic apparatus 1. The alternate long and short dash line indicates the portion where the pulley B12 is supported. The pins 38, 38 'for scratching the hook 20 are
It is fixed to both side plates of the color electrophotographic apparatus 1. Also,
The guide rails 39, 39 'and the holders B37, 37' for supporting the pulley B12 are also fixed to both side plates of the color electrophotographic apparatus 1 by screws, press fitting or adhesion.

While the holder guide rails 25 and 25 'of the cartridge holder 22 are brought into contact with the guide rails 39 and 39' provided on both sides of the color electrophotographic apparatus 1 from the mounting opening, the cartridge 3 together with the cartridge holder 22 is subjected to color electrophotography. Insert into device 1. And the pulley B12
Both ends of the holder are the fixing parts 36, 36 'of the holder B37, 37'.
Get in and stop. Then, the handle 30 is tilted downward, the hook 20 is raised, and the cartridge 38 is fixed to the color electrophotographic apparatus 1 by hooking on the pins 38 and 38 '.

A mounting mechanism for putting the pulley B12 in the holders B37 and 37 'for accurate positioning will be described in detail with reference to FIG.

A holder B37 is fixed to the side plate 120 of the color electrophotographic apparatus 1. Outer circumference 12 'of pulley B12
In order to protect the photoconductor 14, a rubber material which is a soft material is coated. Both shaft ends of the pulley B12 have sliding bearings 123.
Is rotatably supported by the cartridge side plate 31 of the cartridge 3. Then, the slide bearing 123 is positioned by being two-dimensionally constrained by the holder B37 in the vertical direction and the lateral direction.

A wave washer 121 is inserted between the slide bearing 123 and the holder B37 via the top 122 to press the slide bearing 123, and the cartridge side plate 31 and the pulley B12.
Is urged in the direction of the holder B37 'fixed to the side plate of the other color electrophotographic apparatus 1 to perform positioning. The wave washer 121 may be a leaf spring or a coil spring. As a result, the cartridge 3 and the pulley B12 can be positioned, so that the position in the direction perpendicular to the moving direction of the photoconductor 14 can be determined.

FIG. 6 shows an outline of positioning of the cartridge 3 in the insertion direction. A quadrangular prism shaft 12 rotatably supported by a cartridge holder 22 to which the cartridge 3 is attached.
A handle 23 is attached to 5. Quadratic prism shaft 12
5 is rotated by the rotation of the handle 23, and is rotatably supported by a prismatic bearing 124 attached to the side plate of the cartridge holder 22.

At both ends of the quadrangular prism shaft 125, hooks 2 are provided.
0, 20 'are attached, and the hooks 20, 20' and the handle 23 rotate by the same angle. When the handle 23 is rotated in the direction of arrow A, the hook 20 'opens the pin 38' provided on the side plate of the color electrophotographic apparatus 1. Conversely, when the handle 23 is tilted in the direction opposite to the arrow A direction, the hook 2
0'scratches pin 38 '.

When the handle 23 is tilted so that the hook 20 'is surely scratched by the pin 38', the bending spring resistance of the square pole shaft 125 from the side plate of the cartridge holder 22 to the mounting position of the hook 20 'causes the pin 38'. The force that pulls in is acting.

As a result, the cartridge holder 22 and the cartridge 3 are pushed and moved in the direction of the transfer drum 40, and the stopper provided on the side plate of the color electrophotographic apparatus 1
The shaft of the drive pulley 10 abuts and is accurately positioned.
Regarding the relationship between the hook 20 'and the pin 38', the side opposite to the illustrated side has the same configuration.

By adopting the above configuration, the cartridge can be easily and accurately positioned even if the user mounts it on the apparatus.

Next, the relationship between the pulley forming the cartridge 3 and the photosensitive member 14 will be described with reference to FIG. ◆ The diameter D1 of the drive pulley 10, the diameter D2 of the pulley A11, and the diameter D3 of the pulley B12, which are rotatably supported by the cartridge side plate 31, are made the same. The diameter of each pulley is a value after coating the surface with rubber or the like. Diameter D4 of tension pulley 13
Only need not have the same diameter as the other pulleys. The diameter of the transfer drum 40 in contact with the photoconductor 14 is the diameter D1 of the drive pulley 10, the diameter D2 of the pulley A11, and the pulley B1.
The diameter D3 of 2 is approximately an integral multiple.

The diameter D1 of the drive pulley 10, the diameter D2 of the pulley A11, and the diameter D3 of the pulley B12 are configured so that the outer diameter Φ110 mm of the transfer drum 40 is an integer ratio with an accuracy of 0.5% or less. Eccentricity of each pulley is 50μ
Assuming that m and the integer ratio are approximately 1/4, if the pixel pitch unevenness due to the positional difference between the contact positions of the respective pulleys and the transfer drum 40 caused by the error of the integer ratio is 2 μm or less, The calculated diameter tolerance of the pulley is 0.1%. However, as a result of various studies, it was confirmed that if the diameter tolerance is 0.5% or less, the pixel pitch unevenness cannot be visually confirmed under the above conditions.

FIG. 8 shows the measurement result of the positional deviation between the transfer drum 40 and the photosensitive member 14. Transfer drum 40
The misalignment between the photosensitive drum 14 and the photoconductor 14 represents the eccentricity of the drive pulley 10, the pulley A11, and the pulley B12 as 1 dimensionlessly, and the displacement of the transfer drum 40 is different from that when the transfer drum 40 rotates at a constant speed. The vertical axis shows the difference between the two that occurs according to the speed change. For example, when each of the drive pulley 10, the pulley A11, and the pulley B12 has an eccentricity of 50 μm, the maximum positional displacement in the absolute coordinate system is 200 μm, which is four times 50 μm, but the configuration of this embodiment is adopted. As a result, this misregistration occurs in the same manner for each color, that is, for each rotation of the transfer drum 40, so that no relative color misregistration occurs.

According to this structure, even if each pulley has an eccentricity, as shown in FIG. 8, the transfer drum rotates once when each pulley rotates four times. Since a positional shift occurs between the transfer drum 40 and the photoconductor 14 in a similar pattern for each rotation of the transfer drum, it does not appear as a color shift. Although an error as the absolute position of the pixel occurs, it is not conspicuous, so that it is possible to expand to the range where the manufacturing tolerance of each pulley and the transfer drum 40 can be realized.

In order to ensure the above performance, the rotary axes of the transfer drum 40, the drive pulley 10, the pulley A11 and the pulley B12 are required to be parallel. However, the distortion caused by the mechanical manufacturing tolerance and the color electrophotographic apparatus 1
It is important to put the present invention into practical use to what extent the distortion that occurs when placed on an uneven desk is tolerable.
Therefore, increasing the strength of the chassis is one solution, but unlike floor-standing type color electrophotographic devices that have been commercialized so far, desktop and compact color electrophotographic devices are featured. The first issue is how flexible the structure is to maintain the accuracy of the housing.

FIG. 9 and FIG. 9 show the results of studying the feet provided on the bottom plate of the casing, which is one of the configurations of such a color electrophotographic apparatus that is small enough for a disc top and realizes high accuracy of transfer. This will be described with reference to 10.

FIG. 9 is a perspective view of a disc top type color electrophotographic apparatus in which three legs are provided on the bottom plate of the housing. As shown in the figure, the color electrophotographic apparatus 1 of this embodiment has a height of 370 mm, a width of 565 mm, a depth of 520 mm, and a weight of 50 kg or less, excluding the foot portion. Therefore, two people can transport and install the device.

In the color electrophotographic apparatus 1, rear feet 103 are provided on a rear bottom plate provided with a fixing device 80 at a position where a lateral weight can be balanced, and front feet 101 are provided on both lateral sides of the front bottom plate. , 102 are provided.

As a result, as long as the housing of the color electrophotographic apparatus 1 can support its own weight, a structure that is not affected by the unevenness on the desk becomes possible.

With three legs, the color electrophotographic apparatus 1 is temporarily used.
When a load is applied to one side on the rear side of the, the housing of the color electrophotographic apparatus 1 is distorted until the bottom plate comes into contact with the desk. In order to limit this distortion amount to a certain value or less, as shown in FIG.
It is also possible to provide four and 105 and have five legs. Further, without providing the auxiliary legs 104 and 105, it is possible to limit the height of the three legs to limit the distortion.

FIG. 11 shows the experimental result of the distortion of the casing of the color electrophotographic apparatus 1.

The horizontal axis shows the distortion of the housing when the color electrophotographic apparatus 1 is placed on a table having irregularities, and the vertical axis shows the distortion of the cartridge. In the conventional method in which the bottom plate is provided with four legs, if the unevenness of 2 mm on the desk directly causes the distortion of the housing, the distortion of about 1 mm occurs in the cartridge.

On the other hand, in the method of this embodiment in which three legs are provided, the unevenness of 2 mm on the desk is 0.5 m in the cartridge.
Only distortion of m or less occurs. Therefore, the transfer drum 40,
It is possible to obtain the parallel accuracy of the rotation axes of the drive pulley 10, the pulley A11, and the pulley B12.

According to the present embodiment, it is possible to obtain a small-sized, lightweight, desktop-type color electrophotographic apparatus capable of user maintenance capable of highly accurate color matching.

Another embodiment of the present invention will be described with reference to FIG. In this embodiment, the cartridge 3 is mounted on the color electrophotographic apparatus 1 from a direction perpendicular to the conveying direction of the recording medium in the apparatus. Therefore, as shown in the figure, a mounting port is provided on the cover 112 side of the device.

The cartridge 3 is fixed to the cartridge holder 22 by the same method as in the above embodiment. The cartridge holder 22 is inserted from the mounting opening on the cover 112 side of the color electrophotographic apparatus 1. The photoconductor 14 is carried by the user while holding the grips 24 and 24 ′, and while the holder guide rails 27, 27 ′ of the cartridge holder 22 are aligned with the guide rails on the apparatus side from the mounting opening of the color electrophotographic apparatus 1, the handle 30 is provided. Raise and insert.

Then, when the cartridge 3 hits the stopper provided in the color electrophotographic apparatus 1 and cannot be further inserted, the handle 30 is tilted and the hook 20 is hooked to the pins 38 and 38 'to be fixed. Then, the cartridge cover B115 is closed.

In this embodiment, since the cartridge can be mounted in the direction perpendicular to the conveying direction of the recording medium in the apparatus, it is impossible to load the recording medium from the conveying direction due to the location where the apparatus is used. effective. Therefore, by combining with the above-described embodiment, the mounting of the cartridge can be arbitrarily changed according to the direction of use by the user

[0083]

According to the present invention, a color electrophotographic apparatus capable of user maintenance such as a photoconductor, which is small and lightweight,
Print quality is high and high quality recording with little color shift is possible.

Since it is small and lightweight, it can be installed and moved easily and can be made into a desktop type.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a state in which a color electrophotographic apparatus of the present invention is installed on a desk.

FIG. 2 is a perspective view of a photoconductor cartridge.

FIG. 3 is a perspective view illustrating how the cartridge is mounted on the apparatus.

FIG. 4 is a perspective view illustrating a guide means when the cartridge is mounted.

FIG. 5 is a sectional view of a preload mechanism portion of a holder-B.

FIG. 6 is a perspective view of a preload mechanism in a cartridge insertion direction.

FIG. 7 is a side view showing the arrangement of cartridge pulleys and a photoconductor.

FIG. 8 is a diagram showing a measurement result of a positional deviation between a transfer drum and a photoconductor.

FIG. 9 is a perspective view illustrating the arrangement of feet on the bottom surface of the device.

FIG. 10 is a perspective view illustrating another arrangement of feet.

FIG. 11 is a diagram showing the relationship between the distortion of the housing and the distortion of the cartridge.

FIG. 12 is a perspective view for explaining the mounting of the cartridge on the apparatus according to another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Color electrophotographic device, 2 ... Exposure device, 3 ... Cartridge, 10 ... Drive pulley, 11 ... Pull A, 12 ... Pull
Re-B, 13 ... tension pull, 13 '... rubber, 14 ...
Photoconductor, 15 ... Stead B, 16 ... Stead A, 17 ... Blade cleaner, 18 ... Charger A, 19 ... Spring, 20 ... Hook, 21 ... Helical gear, 22 ... Cartridge holder, 23 ... Handle, 24, 24 '... Handle, 25 ... Holder-guide rail, 31, 31' ... Cartridge side plate,
37, 37 '... Holder-B, 38, 38' ... Pin, 3
9, 39 '... Guide rail, 40 ... Transfer drum, 41 ... Cleaner, 50 ... Yellow-developing device, 51 ... Yellow-maguro, 52 ... Magenta developing device, 53 ... Magenta tuna
54, cyan developing device, 55 ... cyan magnole, 5
6 ... Black developing device, 57 ... Black tuna roll, 70
... Manual feed hopper, 71 ... Detection sensor-B, 72 ... Feed roller, 73 ... Hopper, 74 ... Paper feeding roller, 75 ... Paper feeding guide, 76 ... Detection sensor-A, 77 ... Registration roller La, 78 ... Transfer roller, 79 ... Transfer guide, 80
... Fixer, 81 ... Detection sensor-C, 82 ... Discharge roller,
83 ... Ejection tray, 100 ... Desk, 101, 102 ... Front foot, 103 ... Rear foot, 111 ... Cartridge cover, 11
2 ... Cover 115, Cartridge Cover B, 120 ...
Side plates, 121 ... wave washers, 122 ... coma, 123 ... plain bearings, 125 ... quadrangular prism shaft.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuro Akasaki 1-1-1, Higashitaga-cho, Hitachi-shi, Ibaraki Hitachi, Ltd. Information & Video Media Division (72) Inventor Tomio Hayano Higashi-taga-cho, Hitachi, Ibaraki 1-1, 1-1, Information & Video Media Division, Hitachi, Ltd. (72) Inventor, Shoji Houji, 1-1-1, Higashi-Tagacho, Hitachi City, Ibaraki Pref., Information & Media Division, Hitachi, Ltd.

Claims (16)

[Claims] 1. An endless belt-shaped photosensitive member on which an electrostatic latent image is formed by exposure, developing means for forming a toner image on the electrostatic latent image formed on the photosensitive member, and a part of the photosensitive member. In a color electrophotographic apparatus provided with a transfer body to which the toner image is transferred upon contact, a plurality of developing means are arranged in a horizontal row, and a single endless belt-shaped photoconductor is provided to contact these developing means. A color electrophotographic device characterized in that 2. An endless belt-shaped photosensitive member on which an electrostatic latent image is formed by exposure, a developing unit for forming a toner image on the electrostatic latent image formed on the photosensitive member, and a part of the photosensitive member. In a color electrophotographic apparatus provided with a transfer body to which the toner image is transferred, a plurality of developing means are arranged in a row in a row, and the one developing device is arranged below the plurality of developing means so as to come into contact with each developing means. The endless belt-shaped photoconductor is passed in a lateral direction so as to be substantially elliptical, and the endless belt and the transfer body are arranged side by side so that the end surface on the major axis side of the endless belt comes into contact with the transfer body. Color electrophotographic device. 3. The color electrophotographic apparatus according to claim 1, wherein the developing means is provided for four colors. 4. The color electrophotographic apparatus according to claim 1 or 2, wherein the endless belt-shaped photoconductor is bridged over three or more pulleys. 5. The color electrophotographic apparatus according to claim 1 or 2, wherein the endless belt-shaped photoconductor is a cartridge that is bridged over three or more pulleys, and the cartridge is substantially parallel to the arrangement direction of the developing means. A color electrophotographic apparatus characterized in that it can be easily attached to and detached from the color electrophotographic apparatus from a direction parallel to a flat plane. 6. The color electrophotographic apparatus according to claim 4 or 5, wherein the endless belt-shaped photosensitive member is bridged over.
Of the above pulleys, a drive pulley that drives an endless belt-shaped photoconductor is rotatably supported by the device, and one pulley is freely rotatable except a pulley that applies tension to the endless belt-shaped photoconductor. A color electrophotographic apparatus, which is supported by the apparatus in a two-dimensional direction. 7. A color electrophotographic apparatus according to claim 6, wherein the driving pulley and the pulley rotatably supported in the apparatus in a two-dimensional direction are arranged in the axial direction of both pulleys or in the axial direction of either one of the pulleys. A color electrophotographic apparatus comprising a load means for applying a pressure from the color electrophotographic apparatus. 8. The color electrophotographic apparatus according to claim 7, wherein the load means is a leaf spring provided in a pulley mounting portion provided on the apparatus side. 9. The color electrophotographic apparatus according to claim 4 or 5, wherein the surfaces of all the pulleys that apply tension to the endless belt-shaped photoreceptor are covered with a material softer than the base material of the endless belt. A color electrophotographic device. 10. The color electrophotographic apparatus according to claim 9, wherein the material softer than the base material of the endless belt is rubber. 11. A color electrophotographic apparatus according to claim 6, wherein a rubber layer is provided on the surface of the driving pulley, and the rubber layer has a thickness of 2 mm.
A color electrophotographic apparatus having a size of not more than mm. 12. An endless belt-shaped photosensitive member on which an electrostatic latent image is formed by exposure, developing means for forming a toner image on the electrostatic latent image formed on the photosensitive member, and a part of the photosensitive member. In a color electrophotographic apparatus provided with a transfer body to which the toner image is transferred in contact, a single endless belt-shaped photosensitive body which is horizontally long and is in contact with the developing means so as to be substantially elliptical. The endless belt and the transfer member are arranged side by side so that the end surface on the major axis side of the endless belt-shaped photosensitive member is in contact with the transfer member, and the endless belt-shaped photosensitive member is bridged over three or more pulleys. The outer diameter of all pulleys except the pulley that applies tension to the endless belt-shaped photoconductor is the same, and the integer ratio is 0.5% or less with respect to the outer diameter of the transfer body. Color electrophotographic apparatus characterized by being configured as described above . 13. A color electrophotographic apparatus according to claim 12, wherein a plurality of developing means are provided, the plurality of developing means are arranged in a row in a row, and the one endless belt-like member is provided below the plurality of developing means. A color electrophotographic apparatus, in which the photoconductor of 1 is arranged. 14. The color electrophotographic apparatus according to claim 1, wherein the bottom surface of the color electrophotographic apparatus is provided with three legs for installation on a desk. Photographic equipment. 15. The color electrophotographic apparatus according to claim 1, wherein the height of the apparatus main body is 370 m.
A color electrophotographic apparatus characterized by having a thickness of m or less. 16. A color electrophotographic apparatus according to claim 1, wherein the weight of the apparatus is 50 kg or less.