JPS6127564A - Image forming device - Google Patents

Abstract

PURPOSE:To execute easily processing when a paper jam has been generated, and to improve the operability by providing independently plural carrying devices for holding and carrying transfer paper, on one side of a transfer paper carrying path, and executing transfer to each separate color on the transfer paper by each carrying device. CONSTITUTION:Carrying devices 27C, 27M, 27Y and 27BK having a screen belt 26 are provided on every photosensitive drum 7 of laser beam printers 1-4 for generating a signal in accordance with each color. The photosensitive drum 7 forms a latent image of each color on the photosensitive drum 7 by a laser beam L corresponding to each color, and transfers an image on a form P which is developed 9, and fed from the direction of a guide 17, on the screen belt 26 by a transfer part 10. Color matching is executed by starting each photosensitive drum 7 which has detected the tip of the form P by a photointerrupter 24. The screen belt 26 is pressure-welded to the photosensitive drum 7 by an oscillation arm 33, and in the event of a fault such as a paper jam, etc., the arm 33 is detached and only its part is taken out. In this way, the fault is limited locally, and the repair processing is executed easily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] "Industrial Application Field" The present invention relates to an image forming apparatus, particularly a color image forming apparatus.

``Prior Art'' 2 - Methods such as an electrophotographic method, an inkjet method, a thermal transfer method, and the like have been proposed as means for obtaining an image, and image forming apparatuses using each method have been put into practical use. Generally, to obtain a color image, it is necessary to transfer each image (for example, to obtain a full color image, yellow, magenta, cyan, and black images) onto one recording material in layers. . Therefore, a common problem in each of the above-mentioned systems is how to efficiently arrange the means for holding the recording material and the means for forming and transferring images of each color onto the recording material.

Possible placement formats include a method in which a recording material is held and images of each color are transferred while the recording material is moved back and forth or rotationally, and a method in which images of each color are transferred while the recording material is moved in one direction. According to the former method, although the apparatus itself can be made smaller, the printing speed decreases because the recording material is moved back and forth. Although the latter requires larger equipment, the printing speed is much faster and the configuration is simpler than the former, so it is thought that demand for color printers will continue to grow in the future. Since printing speed is a major factor in determining the performance of a printer, it is expected that color printers using the latter method (hereinafter referred to as Dadrum format) will become mainstream.

The following is an explanation of the Dadrum format color printer.

FIG. 1 is a side view of a Dadrum type color printer. Reference characters i, a, , y, and lI are laser beam printers with substantially the same configuration, which are sequentially arranged from the right side to the left side in the figure in the main machine box 3 of the apparatus. Each printer includes an electrophotographic photosensitive drum as an image bearing member which is rotationally driven in the direction of the arrow around a shaft 6, a charger g1, a developing device 9, a transfer discharger 10, and a charger g1, which are arranged sequentially in the rotational direction of the photosensitive drum. ri17-
It consists of a scanning device//, a laser beam scanner l-, etc. disposed above the photosensitive drum.

The laser beam scanner/J consists of a semiconductor laser, a polygon mirror, a lens, a light-shielding plate, etc., and receives the input number of a time-series electrical digital pixel signal S calculated and output from an image reading device or an electronic computer (not shown in the figure). A laser beam L modulated in accordance with the signal is oscillated to scan a portion of the surface of the photosensitive drum 7 between the charging device S and the developing device in the drum generatrix direction, thereby exposing the surface of the photosensitive drum 7. However, the printer
cyan (C) developing toner is used in the developing device, magenta (M) developing toner is used in the print speed, yellow (Y) developing toner is used in the printer 3, and black (BK) developing toner is used in the printer 3. It is used to store toner. Further, the laser beam scanner 7.2 of the printer 1 has a pixel signal S (M) corresponding to the cyan component image of the color image, and the laser beam scanner 7.2 of the printer 1 has a pixel signal S (M) corresponding to the magenta component image. ), the laser beam scanner/J of the printer 3 receives the pixel signal 5 (Y) corresponding to the yellow component image, and the laser beam scanner of the printer 3 receives the pixel signal 5 (sx/J) corresponding to the black component image. ) are input respectively.

Beneath the printers i, a, s, and q are belt drive rollers /3, /3, which are driven with high precision by a drive source (not shown).
A screen belt/J-car is suspended around the screen belt/J-ka.The screen belt/3 is composed of a mesh of Tetron fiber, and is attached to each photosensitive drum between each photosensitive drum and each transfer discharger IO. They are placed close together in the same state and move in the direction of the arrow.

The paper feed device /6 is installed obliquely on the right side of the main machine box 3, and its lower end is close to the right end of the screen belt /l, and a fixing device (not shown) follows the left end of the screen belt /l. A paper ejection means (not shown) is provided.

When the device is powered on, each printer "l'13,
The laser beam scanner/J and other required process equipment are energized or rotated, and the apparatus performs a warming-up operation. Then, when the laser is turned on and the scanner reaches a predetermined rotational speed, it becomes ready.

When a sheet of transfer paper P is inserted into a paper feed guide of a paper feeder, its leading edge is detected by a photointerrupter and a start signal (print sequence start signal) is generated.

This start signal causes each printer/, :1. J,l
The photosensitive drum begins to rotate. Belt driven roller/
7. /II is also driven at the same time, and screen belt /3 also starts running in the direction of the arrow.

The transfer paper P is a register pair/9. Paper feed guide - 〇, register pair ko 11 Pass through paper feed guide a, screen belt/-
3 is supplied on top. screen bell)/& top transfer paper P
is the adsorption charger 3eb.

, 2. ? Receives corona discharge from tl and is reliably adsorbed to the screen belt.

The black tapes (not shown) on the screen pelt lj correspond to the photointerrupters 2QO and IM on the downstream side.

When J4IY and KO1IBK are shut off, image formation on each pre-rotating photosensitive drum of each printer/, 1, J, and 1I is sequentially started in response to the signal.

That is, a cyan image as a color component of a color image is on the 7th surface of the photosensitive drum of the printer 1, a magenta image is on the 7th surface of the photosensitive drum of the printer, and a yellow image is on the 7th surface of the photosensitive drum of the printer 3. A black image is formed on each surface of the photosensitive drum 7, respectively.

And the transfer paper P is the belt screen L! The rotation of the printer moves the printer toward the fixing device; 3. The paper is transported sequentially through the lower part of the printer, and during the passage, each printer's
- /, ko, transfer paper P by 3,4t transfer discharger io
The sides of each printer L, C, 3. Cyan image, magenta image, yellow image formed on the shoe photosensitive drum,
The black images are sequentially superimposed and transferred, and a color image is compositely formed on the surface of the transfer paper P. When the transfer paper P passes through the printer, the static electricity is removed by the separation static eliminator 3 to which an AC voltage is applied, and the transfer paper P passes through the screen belt 1 without producing a discharge pattern.
Separated from 3. After the transfer paper P is discharged outside the machine, all rotations except the scanner and laser are stopped, and one print cycle is completed. Then, the superimposed images of each color transferred to the transfer paper P are fixed by a fixing device (not shown).

``Problems to be Solved by the Invention'' Let us consider what to do when a transfer paper feeding failure occurs in the color printer shown in FIG.

First, if a paper feed failure occurs on the path to the paper feed guide 22, if each paper feed guide is configured so that it can be moved, there will be no problem. . Next, when a feeding failure occurs on the screen belt ls, in order to take out the transfer paper P that caused the feeding failure, the screen belt is and each printer /, ! , ,7. It is necessary to release the + button, move the screen belt IS downward in FIG. 1, and take out the poorly fed paper.

However, moving the screen belt 15 entirely causes new problems as described below. First, since the screen belt 15 is long and there are many parts attached to the screen belt 13, the weight of the unit of the screen belt 15 to be moved becomes heavy, making it extremely difficult to attach and detach the screen belt unit from the viewpoint of operability of the device. Become something. Second, if a feeding failure occurs during a large number of prints, the screen belt 15 is lowered entirely to remove the defective transfer paper.

Then, the other transfer paper P that has been sent normally and on which each image has been transferred is once separated from the printer /, 2, 3 degrees, and the transfer paper is transferred to the printer /, 2.
, I, and II, the state will not be exactly the same as before the feeding failure, so the other transfer papers P must be discarded in the same way as the feeding failure paper. This results in a waste of transfer paper P. Thirdly, printer/, ,2.
．． 7. Since the distance between the laser beam scanner/J and the photosensitive drum 7 is strictly determined in step 1, it is necessary to bring the screen belt 13 into the same contact or close position to the photosensitive drum.

However, as can be seen from the explanation of FIG. 1, since the exposed portion of each printer's photosensitive drum 3.41 covers a wide range, the long screen belt 15 must be placed in the same positional relationship with respect to each photosensitive drum. difficult to maintain.

As mentioned above, a number of problems have arisen due to the integral construction of the transport path in Dadrum type printers. Therefore, it is necessary to pay more attention to feeding defects on the conveyance path than in conventional printers, and it is necessary to configure the conveyance path so that if a feeding defect occurs, it can be dealt with easily and quickly. becomes important.

An object of the present invention is to provide a Dadrum-type image forming apparatus having a transfer paper conveyance path from which only the poorly fed transfer paper can be taken out when a transfer paper feeding failure occurs. purpose.

[Structure of the invention]

"Means for Solving the Problem" The present invention provides an image forming apparatus having a plurality of image forming devices, which includes a plurality of conveyance devices on one side of a transfer paper conveyance path for holding and conveying transfer paper, In addition, each of the conveying devices is capable of coming into contact with and separating from the microscopic image forming apparatus independently of the other conveying devices.

"Example" Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a side view showing an embodiment of the present invention.

Components with the same reference numerals as in FIG. 1 have the same configuration and the same function, so a description thereof will be omitted. FIG. 3 is a perspective view showing a set of the conveying apparatus shown in FIG. 1. Laser beam printers arranged horizontally at equal intervals as in Figure 1/, 3. The respective horizontal parts of the screen belts 2B are placed close to the lowest part of the photosensitive drum 2B in the same state, and the conveying device K0, 27M with the same configuration is installed.
27'l.

Each core BK is a laser beam printer, 7.
They are arranged corresponding to lI.

Therefore, regarding the conveying device, for example, the conveying device core a will be explained as a representative example.

A machine frame 31 of a conveying device 70 is rotatably fixed to three shafts of belt drive rollers supported on the main machine box 3. A belt drive roller and a tension roller 30 are fixed to a machine frame 31 of the conveyance device, and a screen belt 6 is wound around the belt drive roller and tension roller 30. Adsorption charger, 2.7a, ,
2.71) is fixed to the machine frame J/Jζ by sandwiching the roller plate t between the roller plate and 3θ, and the transfer discharger lθ is placed inside the screen belt and 26 at a position facing the lowest part of the photosensitive drum, and the machine frame J / is fixed. In the photointerrupter 2, for example, the transmitting part 41a is fixed to the main machine box j, and the receiving part eb is fixed to the machine frame 31, facing each other.

The separated static eliminator a5 is fixed to the main machine box 5 facing the left end of each screen belt λ6.

A swinging arm 3J and a handle 3S are fixed to a swinging shaft 3S that is supported by the main machine box 5, is located almost below the three shafts of the belt drive roller 2g, and is parallel to the three shafts. Install the rail J/ on the lower side between the roller J and roller de on one side.
, is provided so that it can come into contact with three rollers supported on the tip of the swing arm Jj. A positioning pin 3g is fixed to the upper right side of the machine frame 31, and comes into contact with a positioning member (not shown) provided on the main machine box j in the state shown in FIG.

The main machine box 3 is provided with a removable fixture (not shown), and when the positioning pin 3S comes into contact with the positioning member (not shown), it is fixed to the removable fixture and positioned at a desired position. There is.

The drive wheel l/ is connected to the shaft 3 via an electromagnetic clutch l/-o.
It is connected to a wheel 39 fixed to the wheel. The drive wheels of printer/, J, j, and II are engaged with each other by one check 7 (not shown) and rotated synchronously. Alternatively, each of the three axes may be independently driven by an electric motor and synchronized.

When the transfer paper P is transferred from the conveyance device 170 to the conveyance device 27M, the separation static eliminator λj of the conveyance device 470 works to separate it from the screen belt roller of the conveyance device λ70, transfer it to the screen belt λ6 of the conveyance device JAM, and transfer it to the conveyance device 470. Rich M
It is fixed by the adsorption chargers KOJA and 2JB and moves on the screen belt roller. Transport device, 2? Y, 27B
Similarly, BK is separated by a repeating conveyance device 27, a BK separation static eliminator S, and transferred to a fixing device (not shown).

Suppose now that a feeding failure has occurred between printer 3 and printer DA for some reason. In that case, the electromagnetic clutch qo is disconnected, the unillustrated fixing device of the conveyance device BK is removed, and the swinging arm 33 is rotated clockwise by rotating the handle Sa clockwise, and the conveyance device 27BK is rotated. Rotate around the three axes, lower the right side of the transport device and 27BK,
Remove the poorly fed paper, and then rotate the handle 31I counterclockwise again to rotate the swinging arm 33 counterclockwise, bringing the positioning pin 3g into contact with a positioning member (not shown), and attaching the fixing tool. , the conveyor core BK is returned to its original position, and the clutch is engaged.

In other words, the conveyor device Koku O, J7. Y,,J? Each color on M □ It is possible to dispose of poorly fed paper without applying physical force to the normal transfer paper P on which the image has been transferred. The transfer paper P other than the paper with the feeding error is returned to the printer /,,,2.
．． When 7, 4I is operated, it can be used as printable transfer paper P, so waste of transfer paper P can be avoided. The state of the sending device 27BK at that time is
It is shown by a two-dot chain line in the figure.

Since the conveying device for moving is smaller than the conveying device shown in FIG. 1, it is not heavy during operation, and operability is improved. Since each of the printers l, λ, J, and 'l has its own conveyance device, it is possible to obtain a desired and accurate position of the screen bell (JA) with respect to the surface of the photosensitive drum 70. Furthermore, since the drive of the screen belt rollers of each conveyance device is controlled to the same speed, color misregistration does not occur due to differences in conveyance speed.

In the example shown in Figure 2, each transport device rotates around three shafts, but the drive source and three shafts are connected with a universal joint so that only the front side of the transport device is lowered. The frame 31 may also be supported with the same result.

Figure 1 is a side view showing another embodiment of the present invention. The laser beam printer is arranged in a plane in FIG. 1, but in this embodiment, it is arranged in a vertical plane, and the entire length of the conveyance path rises vertically. The conveyance devices KOKU C, KOKU M, KOKU Y, and 27BK are also provided facing the printers t, s, s, and lI. Components with the same reference numerals as those in FIG. 2 have the same configuration and function, so redundant explanation will be avoided. Since the transfer paper P is conveyed to the left along the upper side of the conveyance device 27BK and sent to the fixing device 11.2 arranged at the upper left of the main machine box 3, the rollers on which the screen belt rollers are stretched are used.

In addition to 30, a belt roller +/ is added.

Belt rollers lIl are also added to the other conveyor devices C2, 2M and core Y, but there is no need to add them if they are not necessary for the structure of the conveyor, screen belt arrangement, etc. When the fixing device (not shown) is removed and the swinging arm 33 is rotated counterclockwise around the shaft 33, the conveying devices Koku C, Koku M, 27Y, and 27BK move counterclockwise around the belt drive rollers. It is possible to dispose of poorly fed paper as described above.

In the printer shown in Figure 1, if a conventional single transport path is adopted, the transport path can be moved in two ways: by moving the entire transport path in parallel to the left, or by setting the center of rotation either up or down. There are ways to make it move.

In the former case of parallel movement, the structure of the parallel movement becomes complicated, and the proportion of space occupied by the parallel movement mechanism in the entire printer device increases.

In the latter case, the space obtained when the conveying device moves around the photosensitive drum 7 of each printer mechanism becomes uneven, and there are places where it is difficult to remove poorly fed paper. In other words, if the conventional conveyance path is used, the device will be disadvantageous.

〔effect〕

As described above, the present invention provides an image forming apparatus having a plurality of visual image forming devices, which includes a plurality of conveyance devices on one side of a transfer paper conveyance path for holding and conveying transfer paper,
In addition, since each conveyance device can be brought into contact with and separated from the microscope image forming apparatus independently of other conveyance devices, when processing defective paper, only the conveyance device at the location where the defective feeding occurs is operated. Light to handle and easy to operate.

Since the other conveying devices remain the same, the transfer paper other than the paper that has failed to feed can be used as is, resulting in high transfer paper utilization efficiency.

At this time, since the structure for moving the conveying device is simple and compact, less space is required for operation, and the entire device is small.

No matter where the poorly fed paper occurs, there is no place where it is difficult to remove the poorly fed paper. We were able to further improve performance compared to the conventional example.

[Brief explanation of the drawing]

FIG. 1 is a side view of a Dadrum type color printer, FIG. 2 is a side view showing a color printer according to an embodiment of the present invention, FIG. 3 is a perspective view showing a set of the conveying device shown in FIG. FIG. 4 is a side view of another embodiment of the present invention. S...Main machine box...Photosensitive drum a. , 2.71)...Adsorption charger Ko4Ic! ,,2 da M
, CogY. , 2 FBK... Photo interrupter 3... Separation static eliminator Coro - Screen belt KOKU C. Rich M, Core Y, Rich BK - Conveyance device Coff @ - Belt drive roller 31... Machine frame 3 pieces... Shaft 33... Swinging arm 34t, Φ handle 3S... Swinging axis 36
...Rail 3g...Positioning pin.

Claims (1)

[Claims] 1. In an image forming apparatus in which a conveyance path for holding and conveying a recording material and a plurality of microscopic image creation devices are arranged on one side of the recording material conveyance path, the conveyance path is equal to the number of the microscopic image creation devices. Accordingly, an image forming apparatus is constructed by being divided into a plurality of parts, and each transporting apparatus constituting a transporting path is capable of approaching and separating from the image forming apparatus independently of other transporting apparatuses. .