JPS62287264A - Image forming device using process cartridge - Google Patents

Abstract

PURPOSE:To form a latent image by one exposing means and to save space by holding an image formation unit which has a photosensitive drum and a developing device on a rotating body. CONSTITUTION:A rotary frame for supporting four process cartridges 2a-2d of cyan, magenta, yellow and black rotatably is held on a support shaft 3 and rotates according to the timing of development. The rotary frame 1 rotates by 90 deg. to rotate the respective cartridges by 90 deg. each, and then a cartridge moves to the lower-most image formation position and stops and is fixed. When this rotary frame 1 rotates, a reture mirror 4 and a pre-exposure light irradiating means 5 move so that they do not impede the cartridge, and move back to their original positions after the respective cartridges move. An image forming process is carried out for every four cartridge and toner particles of the four colors are laminated on a transfer material on a transfer drum 12.

Description

[Detailed description of the invention] 3. Detailed description of the invention (Field of industrial application of the invention) The present invention relates to a color imaging device.

(Conventional technology) In conventional devices of this type, R and G are printed on the photosensitive drum.

Forms latent images corresponding to each color of B, cyan, magenta,
The process is to develop with yellow and black toner and transfer each color to paper that is in close contact with the transfer drum (repeatedly. Units that include a developing device for black toner, a photosensitive drum, a charger, and a cleaner are lined up for the number of toner colors, and a latent image corresponding to each color is formed on each drum, then developed, and then sequentially printed on paper. It is being transcribed into

However, in any of the above-mentioned methods, it is necessary to arrange a large number of developing devices or to arrange a unit of a drum and a developing device, which is not suitable for miniaturizing the apparatus. Furthermore, either method is difficult to replace toner, dispose of waste toner, maintain the charger, and be serviceable, making it unsuitable for use as a small, service-free color image recording device.

On the other hand, one method to improve serviceability and maintainability is the so-called process cartridge system.
In this method, multiple protrusions are attached to a part of the exterior of the cartridge, and a microswitch on the main body of the copying machine is turned to 0N.
-OFFL/, the image exposure conditions, ie, the halogen lamp voltage and laser power, were changed by the combination of turning on a plurality of microswitches.

However, with this method, it is necessary to change the latent image formation conditions and development conditions depending on each cartridge and developer, but with the condition setting method described above, it is difficult to set multiple conditions, and it is complicated. It becomes the composition.

Especially when you want to change latent image formation conditions and development conditions at the same time,
There are limitations to the method using microswitches as described above. Furthermore, when the cartridge rotates, it is even more difficult to press the microswitch reliably.

(Problems to be Solved by the Invention) As described above, the present invention improves the shortcomings of the conventional color image forming apparatus, is small in size, has good image quality, and greatly improves serviceability and user operability. It is a purpose. Further, as a further improvement, image forming conditions for each cartridge can be automatically set.

(Example) FIG. 1 shows an outline of an example using the present invention.

1 in the figure shows four process cartridges 2a, 2b, 2c, 2 of cyan, magenta, yellow, and black.
It is a rotating frame for rotatably supporting d, and the support shaft 3
is held and rotated in accordance with the timing of development.

The configuration of each cartridge containing four color toners is the same, only the toner is different. The structure of this process cartridge and the image forming process will be described in detail with respect to the process cartridge 2a stopped at the image forming position in FIG.

The process cartridge 2a includes a photosensitive drum 8 made of a sensitized organic photoconductor, a primary charger 10, and a cleaner unit 1.
1. On the other hand, a semiconductor laser device (not shown) is provided outside the process cartridge 2a, and the light emitted from this laser is exposed and scanned on the photosensitive drum 8 in the axial direction by a polygon 6 which is rotated at a constant speed by a motor. do. On the way, the laser beam is focused on the photosensitive drum by a lens system 7 and has an f-θ characteristic. 4 in the diagram
is a folding mirror that changes the direction of the laser beam.

A semiconductor laser is modulated by an image signal, a photosensitive drum 8 is exposed according to this signal, and this electrostatic latent image is developed by a developing device 9. On the other hand, the transfer material is fed by a paper feed roller 14 and is evenly wrapped around the surface of the transfer drum 12. A transfer charger 13 applies a corona having a polarity opposite to that of the toner from behind onto the wound transfer material, and the toner on the photosensitive drum 8 is transferred to the transfer material.

The toner remaining after the transfer is collected by the cleaner unit 11 and stored in the cleaner unit 11. The photosensitive drum whose surface has been cleaned receives light from the pre-exposure irradiation means 5 to reduce various memories stored in the photosensitive drum 8, and the photosensitive drum 8 stops rotating. Next, the rotating frame is rotated 90 degrees, and each cartridge is rotated 90 degrees at a time, so that cartridge 2b moves to the lowest image forming position, stops, and is fixed.

When this rotary frame rotates, the folding mirror 4 and the pre-exposure irradiation means 5 move to a position where they do not come into contact with the cartridges 2a, 2b, and return to their original positions after each cartridge has moved.

An image is then created using cartridge 2b. To do this, a semiconductor laser is modulated according to an image signal corresponding to the color of the toner in the cartridge 2b, and the cartridge 2b is
After forming a latent image, it is developed and transferred onto the previous toner on the transfer material wound around the transfer drum 12. The following process is the same as for cartridge 2a.

In this way, the image forming process is performed for each of the four cartridges, and toners of four colors are layered on the transfer material on the transfer drum 12. The transfer material onto which the four color toners have been transferred is separated from the transfer drum 12 by a separating claw 15, conveyed on a conveyor belt 16, fixed by a fixing device 17, and discharged onto a tray 18.

Figure 2 shows how the process cartridge 2 is inserted into the opening 3 from the main body 30.
The process cartridge is shown pulled out through opening 31 when rotating frame l rotates and comes up.
It is designed so that it can be extracted from

The barcode 32 is the exterior part 1 of the process cartridge 2.
It is attached to the surface of 9.

A bar code 32 as shown in FIG. 4 is attached to the outer frame 19 of the cartridge 2, and a reading device shown in FIG. 4 62 for reading this bar code is installed on the main body side corresponding to this position. .

FIG. 3 is a diagram showing the control system of this embodiment.

The signal read from the barcode reading device 40 is
The logic circuit 41 makes the determination, and the signal from the logic circuit 41 is applied to a level switching circuit 46 that switches the level of the developing bias applied from the power supply 47 to the developing device. This circuit 4
6 switches the level of the high-voltage power supply 48 according to the signal to switch the bias voltage applied to the developing device.For example, in the case of AC bias, the bias power supply to be switched is:
Effective voltage, frequency, DC component, and DC bias are DC voltages. On the other hand, the signal from the logic circuit 41 is also applied to a level switching circuit 42 that switches the output level of a power supply 45 for driving the laser 51.

Circuit 42 switches the current from power supply 45 depending on the signal. The low, medium, or high level current corresponding to the signal is further level-corrected in accordance with the beam wavelength via a level adjustment circuit 43 such as a variable resistor, and is applied to the laser drive circuit 49. The adjustment circuit 43 is provided on the main body C side,
The resistance value is adjusted according to the oscillation wavelength of the semiconductor laser 51 built into the main body C side. That is, as the laser beam wavelength becomes longer, the laser drive current increases and the amount of laser exposure to the photoreceptor increases.

In this way, when an indicating means such as a bar code is used, a plurality of image forming conditions can be set depending on the characteristics of the cartridge, such as the latent image forming characteristics of the photosensitive drum and the developing characteristics of the toner.
For example, in a laser beam printer, it is possible to switch the laser light intensity and the development bias singly or both, and many switching levels can be set.

FIG. 5 shows an electrical signal when the barcode 32 shown in FIG.
Select settings for latent image conditions and development conditions. The information of this barcode is read by a reading head that fixes the moving barcode just before the rotating frame 1 rotates and faces the transfer drum 12. In this case, the barcode is installed on the exterior of the cartridge so that the bar is in a direction perpendicular to the direction of rotation of the rotating frame l.

As another example, the barcode may be read contactlessly when the cartridge is at rest. In this case, the process would be as follows.

FIG. 6 shows a device for reading the barcode 32 attached to the outer frame 19 of the cartridge. 63b
The bar code 32 is scanned from end to end by being driven by the bar code 32, and the pattern of the bar code 32 is read by a reflective sensor. The reading device 62 is a semiconductor laser or LE.
It consists of a light source 60 such as D, a lens system for focusing the light emitted from the light source, and a light receiving element 61 that detects the light reflected by the barcode 32 and returned. If the light source is likely to be affected by external light, it is better to use infrared light.
In this case, it is advisable to use a filter that passes only infrared light on the light-receiving element side as well.

Barcode reading is performed every time the laser beam printer is turned on. When the power is turned on, the reading device 31 scans the barcode 20 from end to end, reads the optical pattern, and converts it into an electrical signal.

In the above embodiment, the image forming conditions to be changed were explained using the laser power and developing bias in the laser beam printer, but the halogen voltage for image exposure in the electrophotographic device, the high voltage current of the primary charger, the grid voltage, and the transfer charger are also used. It may be the transfer current, the pre-exposure amount, the development bias conditions mentioned above, or a combination of a plurality of these conditions. Further, in the embodiment described above, a reflection type sensor was used to scan and read the symbol written on the cartridge, but other methods such as a hologram scanner may also be used.

In the above embodiment, each cartridge was configured to face the same direction on the rotating frame like a gondola, but if there is less leakage of toner from the developer or cleaner, the seventh cartridge
As shown in the figure, each cartridge may be fixed on the rotating frame so as to always be radial. In this case, since the cartridge does not rotate, it does not take up much space, and there is no need to move the folding mirror or the pre-exposure irradiation means.

Furthermore, in the above embodiment, the image was written on the photoconductor using a semiconductor laser, but this is an analog color copying machine that separates the original image into colors using filters and sequentially projects each color component onto the photoconductor of each cartridge. However, the present invention can be implemented in the same manner.

(Effects) As explained above, by holding an image forming unit with a small number of photosensitive drums and developing devices on a rotating body, a latent image can be formed with a single exposure means, and space can be saved. It is possible.

Further, as described above, by using a symbol such as a bar code to switch the level of the image forming means of the cartridge, it is possible to switch between a plurality of image forming means and at the same time, it is possible to set a large number of switching levels.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a color laser beam printer used for detailed explanation of the present invention, FIG. 2 is a diagram showing how the cartridge used in the laser beam printer of FIG. 1 is installed, and FIG. 4 is a diagram showing the state of control, FIG. 4 is an explanatory diagram of the barcode, FIG. 5 is a diagram showing the electrical signal corresponding to the barcode in FIG. 4, and FIG. 6 is a plan view of another embodiment of the reading device. FIG. 7 shows explanatory diagrams of other embodiments. In the figure, 1 is a rotating frame, 2a to 2d are process cartridges, 12 is a transfer drum, 13 is a transfer corona discharger,
32 is a barcode, and 62 is a reader.

Claims (2)

[Claims] (1) It has a plurality of electrophotographic process cartridges that are removable from an electrophotographic apparatus main body that includes at least an electrophotographic photoreceptor and a developing device containing toner of a plurality of different colors;
An image forming apparatus using a process cartridge in which the cartridge is supported so as to be replaceable with respect to an image forming position. (2) The cartridge has a pattern indicating image forming conditions, and a detection means installed on the main body reads the pattern in a non-contact manner to control the image forming conditions to suit the cartridge. An image forming apparatus using the process cartridge according to claim (1).