JPH0420453A - Control method for transport of media sheet - Google Patents

Abstract

PURPOSE:To prevent generation of scratches on a receiver sheet by continuing the media sheet transport process at the same speed as receiver sheet, in case the length of receiver sheet is greater than the latent image length, even after the pressure developing process is ended. CONSTITUTION:In case the length of a receiver sheet is greater than the latent image length, the trailing edge of the receiver sheet has not passed the pressure developing part P2 yet at the point of time, and the transport process is contin ued by transport rollers, etc., which are arranged behind. Also the transport process of a media sheet 4 is continued along with the transport of the receiver sheet. This transport is made with a buffer roller 5. The pressurization by pressure rollers 6a, 6b is disengaged, and the buffer roller 5 is moved in the direction of arrow B by a buffer motor until an HPS is put on, and the media sheet 4 is transported. The transport speed of the media sheet 4 at this time is twice as high as the buffer roller 5 moving speed, being the same as the receiver sheet transport speed.

Description

DETAILED DESCRIPTION OF THE INVENTION (AL Industrial Field of Application) This invention relates to image formation in which a latent image is formed on a long media sheet, and this latent image is transferred to a receiver sheet in the form of a cut sheet to form an image. The present invention relates to a media sheet conveyance control method in a method.

fbl Conventional technique (Toe) A long photosensitive pressure-sensitive media notebook is irradiated with imaging light such as reflected light from the original to form a latent image, and a receiver is attached to this latent image.
There is an image forming apparatus that transfers a latent image onto a receiver sheet to form an image by overlapping and applying pressure to the receiver sheet. In such an image forming apparatus, due to the photosensitive and pressure sensitive nature of the media sheet, the media sheet is wound around a supply shaft, stored in a cartridge, and the end portion is pulled out from the cartridge and passed through an exposure section and a pressure development section. It was wound onto a shaft. Exposure processing is performed in the exposure section, and pressure processing (pressure development processing) is performed in the pressure development section. Conventionally, this pressure development process has been carried out using a pressure row that can be pressurized/released.

(C1 Problem to be Solved by the Invention) In the conventional pressure roller, pressure was applied when the latent image on the media sheet faced the pressure roller, and the pressure was released at other times. Conveyance of the media sheet in the forward direction (from the supply shaft to the take-up shaft) was stopped.

However, if the conveyance of the media sheet in the forward direction is stopped at the same time as the pressure is released, the following problems may occur. In other words, if the length of the receiver sheet is longer than the length of the latent image, the pressure on the pressure roller will be released when the rear end of the latent image reaches the pressure developing section, but since the receiver sheet is long, the pressure on the pressure roller will be released. Continue to pass through the pressure development section. At this time, since the conveyance of the media sheet is stopped, the receiver sheet comes into sliding contact with the media sheet, and the rear end of the receiver sheet is scratched by the sliding contact with the media sheet. Such scratches are undesirable because they degrade image quality.

An object of the present invention is to provide a media sheet conveyance control method that prevents scratches from occurring at the rear end of the receiver sheet even when the receiver sheet length is longer than the latent image length.

(d+Means for Solving the Problems) This invention provides an image forming method in which a receiver sheet is superimposed on a latent image formed on a media sheet and pressed, and the image is transferred to the receiver sheet. When the length of the receiver sheet is longer than the length of the latent image, the pressurizing force on both sheets is released after the media sheet is fed by the length of the latent image, and then at least the rear end of the receiver sheet passes through the pressure developing section. It is characterized by conveying the media sheet at the same speed as the receiver sheet until it passes.

(e) Effect In this invention, when the receiver sheet length is longer than the latent image length, even after the pressing force pressing both sheets is released, at least until the rear end of the receiver sheet reaches the pressure developing section, the media The sheet continues to be conveyed. At this time, since the conveyance speed of the media sheet is the same as the conveyance speed of the receiver sheet, the receiver sheet and the media sheet will not rub against each other, and the surface of the receiver sheet will not be scratched. .

ff) Embodiment FIG. 3 is a schematic front view of a copying machine that forms an image using a media sheet.

A document table 1 is mounted on the E side of the copying machine body, and a document to be copied is placed thereon. An optical system 2 including a light source, a mirror, a lens, etc. is provided on the lower side of the document table 1, and guides reflected light from a document placed on the document table 1 to an exposure section to be described later.

On the other hand, a media cartridge 3 is detachably provided on the left side of the center inside the main body of the copying machine. The media cartridge 3 includes a supply shaft 3a and a take-up shaft 3b, and an unused media sheet 4 is wound around the supply shaft 3a. Supply shaft 3
a. The take-up shaft 3b is connected to a motor (not shown), and can be used in the forward direction (the direction in which the media sheet is sent from the supply shaft 3a to the take-up shaft 3b) or in the reverse direction (the direction in which the media sheet is sent from the take-up shaft 3b to the supply shaft 3a). ). media sheet 4
This is a photocurable material (2) in which microcapsules encapsulating a color-forming dye, etc. are coated on a support made of a resin film, and is paired with a receiver notebook to be described later.

A developing material that causes the color-forming dye to develop is applied to the receiver sheet, and when the microcapsules of the media sheet are destroyed and the color-forming dye flows out, the color is developed. Note that there are also media sheets with different configurations. For example, the media sheet may be coated with a photocurable material or microcapsules encapsulating a colored dye, or the media sheet may be coated with a developing material along with microcapsules encapsulating a color-forming dye. In this case, the receiver sheet may be any paper sheet.

The media sheet 4 is the supply shaft 3a of the media cartridge.
The sheet is pulled out from the main body of the copying machine, passes through the exposure section PI, the buffer roller 5, and the pressure development section P2 on the copying machine main body side, and is then wound onto the winding shaft 3b. As described above, the reflected light from the original placed on the original platen 1-H is guided to the exposure section PI, and
to form a latent image on the media sheet. Further, the pressure developing section P2 is composed of a pair of pressure rollers 6a and 6b. The pressure rollers 6a and 6b can be pressurized/released by a pressure mechanism including a spring and a cam (not shown). Note that 6c and 6c are backup rollers for applying pressure uniformly to the pressure rollers 6a and 6b in the axial direction.

There are paper cassettes 7a, 7t) on the right side of the copying machine body.
<m is provided, and a receiver sheet 8 is housed therein. Receiver sheets of different sizes are stored in paper cassettes 7a and 7b, and during image formation, receiver sheet 8 is fed from one of the cassettes according to a selection from an operation section on the top of the copying machine main body. The fed receiver sheet 8 is stopped once by a timing roller 9 in front of the pressure rollers 6a, 6b, and is fed to the pressure rollers 5a, 5b by rotating the timing roller 9 at a predetermined timing. The latent image is then superimposed on the latent image on the media sheet E in the pressure development section P2, and pressure development processing is performed.

A driving force is transmitted to the buffer roller 5 from a motor (not shown), and the buffer roller 5 is movable in the directions of arrows A and B. The home position (HP) of the buffer roller 5 is the position of the home position sensor (HPS), and movement control in the directions of arrows A and B is performed with this position as a reference. Also ICHP
S (image cut home position sensor) is a sensor used when the length of the receiver sheet is shorter than the length of the latent image.

FIG. 1 is a flowchart showing a media sheet conveyance control procedure according to the present invention, and FIG. 2 is a diagram showing the conveyance state of a media sheet and a receiver sheet.

First, the supply shaft 3a is unlocked, the take-up shaft 3b is locked,
With the pressure rollers 5a and 5b in a pressure released state, the buffer roller 5 moves in the direction indicated by the arrow, and during this time, the original on the original platen 17 is scanned by the optical system 2, and its reflected light is guided to the exposure section P1 (nl→ n2). At this time, the leading end of the latent image 41 formed on the media sheet 47 by exposure is designated 412, and the trailing end is designated 41b (see FIG. 2(A)). When the exposure process is completed, the movement of the buffer roller 5 is stopped, the supply shaft 3a is locked, and the take-up shaft 3b is unlocked (n3). Then, the buffer roller 5 starts moving in the direction of arrow B, and at the same time, the timer starts (n4→n5). This timer measures Ta time n6
), during this time the leading end 41a of the latent image 41 reaches the pressure developing section P2 (FIG. 2(B)). At the same timing as the end of this latent image reaches, the end of the receiver sheet 81 reaches the pressure developing section P.
The receiver 1-81 is fed by 1-81 cm so as to reach the sheet 2, and pressure rollers 6a and 6b are applied with the leading ends of both sheets 41 and 81 overlapped (n7).

After this, the buffalo roller 5 continues in the direction of arrow B, I
It moves until the CHPS turns on, and stops moving when the ICHPS turns on as shown in Figure 2 (C) (n8
→n9). Then, the lock of the supply shaft 3a is released, and the media sheet 4 is ejected from the supply shaft until the rear end of the latent image 41 reaches the pressure development section P2, that is, until time Tb has elapsed, and is subjected to pressure development processing. continues. (nl
O→nll→n12).

FIG. 2(D) shows the state at the end of the pressure development process. As shown in the figure, at this point, the rear end of the latent image 41 on the media has reached the pressure developing section P2.
The pressure development process has now been completed.

However, if the length of the receiver sheet 81 is longer than the length of the latent image 41, the receiver sheet 1-81 is
The rear end has not yet passed through the pressure developing section P2, and the transport process is continued using the vj and transport roller keys located at the rear. Corresponding to the conveyance of the receiver sheet 81, the conveyance process of the media sheet 4 is also continued. This conveyance is performed by the buffer roller 5. Pressure roller 6a
, εib pressure is released, and the buffer motor moves the buffer roller 5 in the direction of arrow B until the HPS is turned on to convey the media sheet (n 13→n
14-+n15-+n16-+n17→n18) The moving speed of the camera 5 and the receiver
This is the same speed as the conveyance speed of the table 81.

In this manner, after the pressure development process, by transporting the media sheet by moving the buffer roller 5, it is possible to transport the media sheet at the same speed as the receiver sheet, thereby preventing scratches.

A mechanism for moving the buffer roller 5 at a positive constant speed is easier to construct than a mechanism for moving a winding shaft or the like whose diameter changes with use at an accurate constant speed. In this example, the distance between HPS and ICHPS / Alternatively, for example, by finding the difference between the latent image length and the receiver sheet length,
The position of ICHPS may be moved accordingly. Furthermore, it is also possible to use a timer for control instead of a sensor.

(g) Effects of the Invention As described above, according to the present invention, when the receiver sheet length is longer than the latent image length, the conveyance process of the media sheet continues at the same speed as the receiver sheet even after the pressure development process is completed. Ru. Therefore, the media sheet and receiver sheet do not rub against each other, and the receiver sheet
No scratches will occur.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing the media sheet conveyance control procedure according to the present invention, FIGS. 2 (A) to (D) are diagrams showing the conveyance state of the media sheet, and FIG. 3 is an image formation using the media sheet. 1 is a schematic front view of a copying machine that performs 3a-supply shaft, 3b-take-up shaft, 4-media sheet, 5
-Buffalo roller, 6a, 6b-Pressure roller, HPS-
Home position sensor, I CHPS-Easy cut home position sensor.

Claims (1)

[Claims] (1) In an image forming method in which a receiver sheet is superimposed on a latent image formed on a media sheet and pressure is applied to transfer the image to the receiver sheet, the length of the receiver sheet is longer than the length of the latent image formed on the media sheet. When the media sheet is long, the pressing force on both sheets is released after the media sheet is fed by the length of the latent image, and then the media sheet is transported at the same speed as the receiver sheet until at least the rear end of the receiver sheet passes through the pressure developing section. A media sheet conveyance control method characterized by: