JPH0331156A - Image forming device - Google Patents

Abstract

PURPOSE:To surely return a buffer roller to a correct position by providing a returning means returning the buffer roller to the home position at the time of automatic loading after moving it by a fixed quantity in the withdrawing direction of a medium sheet when a leader sheet at the top of the medium sheet is automatically loaded. CONSTITUTION:A front cover is closed, a switch is turned on, the drive section of the motor of a buffer roller 64 and a clutch are turned on, and the buffer roller 64 is moved in the arrow A direction for a fixed period. The motor is reversely rotated to move the buffer roller 64 in the arrow B direction, and the HP sensor S1 of the buffer roller 64 is turned on after a preset period elapses. This position indicates the home position 64 when an image is formed. Reverse rotation is further continued, the HP sensor S1 is turned off, and this position is the home position 64 at the time of automatic loading. The motor of the buffer roller 64 is stopped at this position, and the buffer roller 64 is returned to this position 64.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to an image forming apparatus that uses a rolled media sheet, and more particularly to an image forming apparatus that includes a buffer roller for pulling out the media sheet.

(bl Prior Art) Images using a media sheet coated with microcapsules containing a photocurable material and an image forming agent, which have been developed in recent years, and an image receiving sheet coated with a developing material that reacts with the image forming agent to form a color. The formation method is performed as follows.

When an image-receiving sheet is placed on a media sheet on which a selectively cured image has been formed by exposure of the original image and pressure is applied by a pressure roller, the uncured image forming agent in the microcapsules flows out and reacts with the developing material on the image-receiving sheet. The color develops and an image is formed.

Therefore, in general, media sheets are stored in a media cartridge in the form of a roll in order to prevent exposure to external light and destruction of microcapsules due to external force until the original image is exposed.

The media cartridge is detachably attached to the main body of the image forming apparatus to improve operability.

On the other hand, when forming an image, it is necessary to pull out the media sheet, and after pulling it out, it is necessary to convey it smoothly while always applying tension so that it does not loosen. For this reason, generally, a buffer roller provided in front of the pressure roller is moved as appropriate.

Here, the home position is set so that the pull-out length of the media sheet can be accurately controlled. The home position during image formation is SHP (exposure start home position).

After clearing a jam, when the front cover is closed, when the print switch is operated, when the power switch is turned on, etc., if the buffer roller is not in the SHP, the S
Return to HP.

Furthermore, in order to code the media sheet to each roller of the main body when the media cartridge is attached to the main body of the image forming apparatus, various measures have been taken, such as connecting a rigid league sheet to the tip of the media sheet to make the work easier. Automation of loading has also been developed and proposed (Japanese Patent Laid-Open No. 632173530).

During autoloading, since the media sheet is set on a plurality of rollers such as a pressure roller, it is necessary to make the movement of the media sheet as easy as possible. Therefore, RI (P (loading home position)) is set as the second home position for the He' sofa roller.

When replacing the media cartridge, turn the buffer roller to R.
After returning to the HP, start loading the media sheet.

(C1 Problem to be Solved by the Invention In an image forming apparatus using a roll-shaped media sheet as described above, the media sheet is smoothly fed out from the media cartridge, and smoothly wound onto the take-up shaft after going through each process. If the sheet is fed diagonally, it may become wrinkled or damaged, increasing the load on pressure rollers, etc., and leading to problems such as drive locking.In other words, the entire image forming apparatus Thereafter, it is determined whether or not the media operates normally.Smooth conveyance of the media sheet depends on whether or not the leader sheath 1 at the leading end of the media sheet is correctly loaded.

However, even though the leadership 1 is rigid,
The film has a thickness of 100 to 250 μm, and because the pressure roller is subjected to a high load overcurrent, it is difficult to insert the leading edge of the leader sheet correctly perpendicular to the roller axis. If there is some kind of disturbance, such as a buffalo roller not returning to the correct home position during autoloading, or a slight disturbance in the image forming path to the pressure roller, the leading edge of the league sheet may become slanted or get stuck on the roller. It may bend or bend, making it impossible to load correctly.

On the other hand, when a media cartridge runs out during an image forming operation and the media cartridge is replaced, a new media cartridge is generally installed and a league sheet is inserted. Autoloading begins when the media cartridge is properly installed. At this time, the buffalo roller was moved from the SHP to the RHP as pre-processing during autoloading. However, in many cases, the buffalo did not reliably return to RHP. If Buffalora does not definitely return to RHP,
The image forming path of the media sheet leading to the pressure roller cannot be formed correctly, and there is a high possibility that a mistake will occur in the autoloading of the league sheet.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus in which the buffer roller reliably returns to the home position during autoloading.

(Means for Solving Problem d1) This invention includes an autoloading means for setting a media sheet stored in a media cartridge in an image forming path including a buffer roller, and moves the buffer roller to remove the media from the media cartridge. In an image forming apparatus in which a home position of a buffalo roller during image formation for drawing out a sheet and a home position of the buffalo roller for O1-rope inking are set, the buffalo roller is used for drawing out a media sheet during autoloading. The present invention is characterized in that a return means is provided for returning to the home position at the time of autoloading after moving a certain amount in the direction 'FJJ'.

(81 Effect) In the image forming apparatus according to the present invention, when a media cartridge is installed and autoloaded, the buffer roller is moved a certain amount in the direction of pulling out the media sheet in the preprocessing operation, and then returned to the RHP. By moving the RA to the almost opposite side of the RHP, the RH
After keeping an appropriate distance from P, move towards RHP.

This gives momentum to the buffalo and allows the buffalo to reliably return to RHP. Therefore, autoloading is started after a correct image forming path is formed at the correct position during autoloading. The league sheet is correctly conveyed to the pressure roller and wrapped around the take-up shaft of the media cartridge, so that autoloading errors do not occur due to the position of the buffer roller (f) Embodiment FIG. 5 shows the implementation of the present invention. 1 is a schematic configuration diagram of an example image forming apparatus.

A document table 2 is disposed on the upper surface of the image forming apparatus main body l, and an optical device 3 including a light source, a mirror, a lens, etc. is arranged below the document table 2.
is installed. A media cartridge 5 that stores a media sheet 51 is installed in a bucket 50 located slightly to the left of the center of the main body 1, and the media sheets 1 to 51 include a tractor roller 61, an exposure plate 62, a conveyance roller 63, a buffer roller 64, and a pressure roller. 65, transported through 66,
It is wound up on the winding shaft 53 of the media cartridge 5.

A paper feeding section 4 is disposed at the lower right side of the main body 1, and feeds the image receiving sheet to a pressure developing section 6. A glossing device 7 is provided on the left side of the pressure developing section, and a wandering paper section 8 is provided on the left side of the main body 1.

Next, the image forming operation will be explained.

First, the optical device 3 scans a document placed on the document table 2. At this time, the buffer roller 64 is moved from the image forming home position (SHP) 64°'' in the direction of arrow A, the media sheet 51 is pulled out, and the reflected light from the document is irradiated onto the media sheet on the exposure plate 62. Exposure to light, thus forming a selectively cured image on the media sheet.

When the exposure is completed, the buffer roller 64 is moved in the direction of arrow B to convey the area where the selectively cured image has been formed to the pressure developing section 6. The buffer roller 64 stops when it returns to 5HP64'''. The image receiving sheet is fed from the paper feeding section 4,
The image is sent to the pressure developing section in synchronization with the selectively cured image on the media sheet 1-. Note that 64゛ is the original position of the buffer roller at the time of autoloading.

The media sheet and the image receiving sheet are pressed by pressure rollers 65 and 66 in a superimposed state.

Then, the uncured microcapsules on the media sheet are destroyed, and the image forming agent flows out and reacts with the developing material on the image receiving sheet 1 to develop color.

The media sheet that has undergone pressure development is wound up on the winding shaft of the media cartridge, and the image receiving sheet is sent to the glossing device 7.
It undergoes heat treatment and is discharged to the discharge section 8.

Also, on the upper right side of the main body, there is a cover switch S3 that is turned on and off by opening and closing the front cover (not shown), an HP sensor S1 that detects the home position of the buffalo roller 64, a pressure roller 66 and a winding shaft near the buffalo roller. Various sensors such as a winding detection sensor S2 for detecting winding around the winding shaft 53 are arranged at appropriate positions between the winding shafts 53 and 53.

FIG. 3 is an external perspective view of the buffalo roller and its HP sensor.

The buffer roller 64 is pivotally supported by the guide 11.

A bearing portion 12 is formed at one end of the guide 11, and a support rod 1 fixed to the image forming apparatus main body is attached to the bearing portion 12.
3 is inserted, and the bearing portion 12 slides along the support rod 13. The longitudinal direction of the support rod 12 is the direction of arrows A and B in FIG. Also, guide 1
A roller 14 is pivotally supported at the other end of the rail 15.
Rotate between 16. The wire 17 is looped around the guide 11. Wire 17 coming out from guide 11
After being wound around the winding roller 18, the upper pressure roller 66
The guide 11 is returned to the guide 11 via a pulley (not shown) disposed on the side surface of the guide 11. When the winding roller 18 rotates in the direction of arrow A, the buffer roller 64 moves in the direction of arrow A, and when it rotates in the direction of arrow E, it moves in the direction of arrow B. The shaft 19 is pivotally supported by the frame of the main body of the image forming apparatus. T-I
The P sensor S1 is disposed almost at the border of each home position of the buffer rollers on the rail 15 and 16, and
A detection plate 11a is formed at the end on the rail side.

FIG. 4 is a diagram showing the positional relationship between the home position of the buffalo roller and the HP sensor.

As described above, the buffer roller 64 has a home position (SHP) 64'' during image formation and a home position (RHP) 64'' during autoloading.

The HP sensor S1 is provided almost at the boundary between the RHP and SHP. A detection plate 11a is attached to the buffer roller 64, and the detection plate 11a moves together with the buffer roller. The length of the detection plate 11a is β, which is RI-I P 6
Matches the distance between 4' and 5HP64''.Sensor S
1 is a transmission type optical sensor, and this sensor S1 is a detection plate 11.
The buffer roller 64 is turned on when the detection start edge of a is detected, and the buffer roller 64 is located at S I-I P. When the detection end edge is detected, the buffer roller 64 is turned off and the buffer roller is turned on.
Located on HP.

Next, the automatic loading operation of the media sheet will be explained.

Open the front cover (not shown), set a new media cartridge 5 in the brush plate 50, fit the leader sheet L connected to the tip of the media sheet 51 into the tractor roller 61, set the bald plate 50 in the main body, and the sensor (not shown) etc. It enters autoloading mode. next,
When the front cover is closed 1 2 , the cover switch S3 is turned on. Using this signal as a trigger, the drive section of the buffalo roller motor and the buffalo roller clutch (not shown) are turned on to move the buffalo roller 64 in the direction of arrow A for a predetermined period of time. Thereafter, the buffalo roller 64 is moved in the direction of arrow B by reversing the buffalo roller motor. If no trouble occurs, the HP sensor S1 of the buffalo roller 64 is turned on at a certain time after the buffalo roller starts reversing. At this time SHP
Therefore, if the reverse rotation continues further, the HP sensor S1 turns off. When this is turned off, it is the autoloading RHP, so the buffer roller motor is stopped at this time.

As described above, since the buffalo roller is moved to the almost opposite side of the RHP and then returned to the RHP, the buffalo roller is given momentum and can reliably return to the RHP.

After the buffer roller 64 reliably returns to RI-IP, autoloading is started. That is, the tractor roller 61 is rotated, the pressure roller 65 and the take-up shaft 53 are rotated, and the leader sheet is conveyed. At this time, since the buffer roller 64 is located at the RHP, the image forming path is formed correctly and loading errors are less likely to occur. When the leading edge of the leader sheet passes through the pressure roller and comes into contact with the adhesive portion of the winding shaft 53 and is securely wrapped, the leader sheet on the conveyance path becomes taut and the winding detection sensor S2 is turned on.

Thereafter, the take-up shaft is rotated by a predetermined amount to complete autoloading.

FIG. 2 is a block diagram of a part of the control section of the image forming apparatus.

A ROM 21 and a RAM 22 are connected to the CPU 20.
Via 1023, the drive section 24 of the main motor 25, the drive section 26 of the buffer roller motor 27, the control circuit 28,
A sensor group 31 including sensors such as a cover switch S3, HP sensor S1, and wrapping detection sensor S2 is connected.

A clutch 29 that transmits the rotation of the buffer roller 64 to the main motor, and a clutch 30 that transmits the rotation of the main motor to the pressure roller 65 are connected to the control circuit.

The CPU 20 controls the entire image forming apparatus, and the ROM 2
1 has a control program written in advance. RAM
Other working areas such as a timer are assigned to 22. When the cover switch S3 is turned on, the CPU 20 takes in the signal via the l1023 and outputs an on signal to the motor drive unit 26 and control circuit 28 of the buffer roller. This turns on the clutch 29, transmits the rotation of the motor to the buffalo roller 64, and moves the buffalo roller. The timer allocated in the RAM 22 starts at the same time as the buffer roller motor starts rotating.
After a certain period of time has elapsed, the HP sensor S1 is turned on. After that, since the buffalo continues to move, HP Senna S1 is turned off. The CPU 20 takes in this on/off signal via l1023 and outputs an off signal to the motor drive section 26 and control circuit 28 of the buffer roller.

As a result, the clutch 29 is turned off, the motor is stopped, and the buffer roller 64 is stopped. In this way Buffalora 6
4 returns to the home position at autoloading.

FIG. 1 is a flowchart of the autoloading control operation of the image forming apparatus.

Open the front cover (not shown) of the main unit (nl), and install or set the media cartridge (n2). If you close the media car 1 ridge correctly and close the front cover (n
3) Cover switch S3 is turned on (n4). Then, the motor and clutch 29 that drive the buffer roller are turned on (n5), and the buffer roller is moved. At the same time, timer T is reset and started (n6). When a certain period of time T has elapsed (nl), the buffer roller motor is reversed (n8), and the timer T is reset and started again (n9). When the predetermined time T2 has elapsed, the HP sensor S1 is turned on (n11). If the HP sensor S1 is not turned on even after the predetermined time T2 has elapsed, it is assumed that some abnormality has occurred and the process is performed accordingly. HPsen・su°S1
Immediately after turning on, Sl turns off (r+12). As a result, it is confirmed that the buffer roller has returned to the home position at the time of autoloading as described above, and the conveyance of the leader seat 1 is started (n14) in this correct image forming path state. Note that T, , and T2 are each constant set values.

In the above configuration, n5 to n12 correspond to the buffer roller return means of the present invention.

In this example, it was confirmed that the buffalo roller was located at the RHP when one HP sensor was turned on and off. There are ways to check.

(g) Effects of the Invention As described above, according to the present invention, when autoloading the leader sheet 1 at the leading end of a media sheet in an image forming apparatus in which a media cartridge is installed, the return means moves the buffer roller partially into the sheet. Move it almost to the opposite side of the pull-out direction, and then return it to the home position during autoloading. This gives the buffalo a boost and ensures that it returns to the correct home position during autoloading. Therefore, when autoloading is started thereafter, the leader sheet is correctly conveyed, reaches the pressure roller, and wraps around the take-up shaft of the media cartridge, so that loading errors do not occur due to the position of the buffer roller.

Therefore, the occurrence of troubles during autoloading of the leader sheet is reduced, and operability is improved.

[Brief explanation of drawings]

FIG. 1 is a flowchart of an autoloading control operation of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram of a part of the control section of the image forming apparatus. FIG. 3 is an external perspective view of the buffalo roller of the image forming unit 11 and its HP sensor. FIG. 4 is a diagram showing the positional relationship between the home position of the buffalo roller and the HP sensor. FIG. 5 is a schematic configuration diagram of the image forming apparatus. 7 8 3-Optical device, 5-Media cartridge, 51-Media sheet, 52-Supply shaft, 53-Take-up shaft, 64-Buffer roller, 65.66-Pressure roller, S1-HP sensor, L-IJ- Dashit.

Claims (1)

[Claims] (1) A buffer during image formation that includes an autoloading means for setting a media sheet stored in a media cartridge in an image forming path including a buffalo roller, and that moves the buffalo roller to pull out a media sheet from the media cartridge. In an image forming apparatus in which a home position of the buffer roller and a home position of the buffer roller during autoloading are set, the buffer roller is moved a certain amount in the direction of pulling out the media sheet during autoloading, and then the home position of the buffer roller during autoloading is set. An image forming apparatus characterized by being provided with a return means for returning to a position.