JPH056069A - Electrostatic recording method - Google Patents

Abstract

PURPOSE:To prevent the stain on an image due to remaining developer in a developing device when color image recording is excuted with a notary developing device. CONSTITUTION:Developing position is one developing device 19a and electrostatic recording paper 10 is sent in a recording direction (A direction) and recorded then developed. Thereafter the developing device 19a is moved to the opposite direction of the recording and the developing position is center position between the developing receptacle 19a and next developing receptacle 19d, then in this state, the electrostatic recording paper 10 is unwound. In such a manner, the drying groove side of the developing receptacle 19a used immediately before makes an approach to the electrostatic recording paper at the time of the unwinding of the electrostatic recording paper. Since little developer remains at the drying groove side, the stain on the image part of the electrostatic recording paper by the remaining developer is not generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electrostatic recording in which a recording medium is reciprocated a plurality of times through a recording position and a developing position, and electrostatic latent image formation and development of images of a plurality of colors are repeated to obtain a color image. More specifically, the present invention relates to an electrostatic recording method using a rotary developing device.

[0002]

2. Description of the Related Art In this type of electrostatic recording method, development of each color of black, cyan, magenta and yellow is generally required.

Conventionally, for such multi-color development, a plurality of independent developing devices arranged in series along a conveyance path of a recording medium (electrostatic recording paper) have been used, or a rotating body has been used. A so-called rotary developing device is used in which a plurality of developing devices provided are selectively moved to a developing position by rotation of a rotating body. Examples of such a rotary developing device are disclosed in, for example, JP-A-63-41871 and JP-A-6-41871.
No. 3-149664, JP-A-63-191169, and JP-A-64-62672.

Generally, the structure using the rotary developing device is different from the structure using a plurality of developing devices arranged in series,
The arrangement space is small, which is advantageous for downsizing of the apparatus, and the control of the position of the developing device becomes easy. An example of this rotary developing device will be described with reference to FIGS. The rotary developing device 18 includes a rotating body 20 arranged to rotate at a predetermined position below the electrostatic recording paper 10, and four developing units arranged on the rotating body 20 at equal intervals in the circumferential direction. That is,
The developing device 19a for black, the developing device 19b for cyan, the developing device 19c for magenta, and the developing device 19d for yellow are provided. Each of these developing devices is provided with a plurality of developing grooves 24 through which a developing solution circulates, an air groove 25, and a drying groove 26 through which vacuum suction is performed, and
A developer circulating system (not shown) for circulating the developer of the corresponding color is connected. Further, a rotating body drive system (not shown) is connected to the rotating body 20 so as to rotate the rotating body 20 and stop it at a predetermined position so that a desired developing device or an intermediate position between the developing devices is a developing position. Has been done.

An electrostatic recording operation using such a rotary developing device 18 has been performed in the procedure shown in FIGS. 7 (a) to 7 (j). That is, in the ready state of (a), the intermediate position between the yellow developing device 19d and the black developing device 19a of the rotary developing device 18 is located at the developing position for the electrostatic recording paper 10. From this state, first, as shown in (b), the rotating body 20 of the developing device 18 rotates counterclockwise to move the black developing device 19a to the developing position and stop,
In this state, the electrostatic recording paper 10 is conveyed in the direction of arrow A (recording direction), and a black image is recorded. afterwards,
As shown in (c), the rotator 20 further rotates counterclockwise, and the black developing device 19a and the cyan developing device 19b are rotated.
Is in the intermediate position, and in that state, the arrow A on the electrostatic recording paper 10
Direction dry feed and the opposite direction (arrow B direction)
Is rewound. After the rewinding is completed, as shown in (d), the rotating body 20 further rotates in the counterclockwise direction so that the cyan developing device 19b reaches the developing position.
0 is conveyed in the direction of arrow A, and a cyan image is recorded. Thereafter, as shown in (e), the rotating body 20 further rotates counterclockwise to reach the intermediate position between the cyan developing device 19b and the magenta developing device 19c, and in this state, the direction of the arrow A of the electrostatic recording paper 10 is reached. And the rewinding in the opposite direction. Hereinafter, by repeating the same operation as shown in (f), (g), and (h), magenta,
Each yellow image is recorded. After the recording of the final color (yellow) is completed, as shown in (i), the rotating body 20 rotates in the opposite direction from the previous time, that is, in the clockwise direction, and the magenta developing device 19c and the yellow developing device 19d are rotated. The intermediate position is reached, and in that state, the dry feed and discharge in the direction of the arrow A are performed, and thereafter, the rotating body 20 further rotates in the clockwise direction as shown in (j) to return to the ready state shown in (a).

[0006]

However, according to such a construction, there is a problem that the developing solution remaining in the developing device adheres to the electrostatic recording paper, and the recorded image is deteriorated.

As a result of examining the cause of the above problem, it was found that the problem was caused by the following reasons. Hereinafter, the reason will be described by taking the black developing device 19a as an example. During development,
As shown in FIG. 5, the electrostatic recording paper 10 travels in the recording direction (direction of arrow A) on the black developing device 19a, and the electrostatic latent image formed on the electrostatic recording paper 10 has a developing groove 24. The developing solution in the inside is applied, and the excess developing solution is sucked and removed by the drying groove 26. During the development, the developer is often attached to the end portion 27 of the developing device 19a on the side of the developing groove 24. After the development is completed, as shown in FIG. 6, the rotating body 20 is rotated counterclockwise, and the electrostatic recording paper 10 is rewound in the arrow B direction with the intermediate position between the developing device 19a and the developing device 19b as the developing position. At that time, since the end portion 27 of the developing device 19a, to which the developing solution is attached, is located close to the electrostatic recording paper 10, the developing solution is applied to the electrostatic recording paper 10 when the electrostatic recording paper 10 is rewound. It adheres to the and stains the image.

The present invention has been made in view of the above-mentioned problems, and it is possible to obtain an excellent recorded image without adhering the developing solution remaining in the developing device to the developed recording medium. The purpose is to provide a recording method.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention sets a recording medium in a recording direction with one of a plurality of developing devices provided in a rotary developing device being in a developing position. To the recording medium, the recording means forms an electrostatic latent image on the recording medium, and the electrostatic latent image is developed by the developing device. After the recording is completed, the intermediate position between the developing device and the adjacent developing device is set to the developing position. In the method of moving the recording medium in a direction opposite to the recording direction, after the development is completed, the developing device used for the development is moved in a moving direction at the time of recording of the recording medium, that is, a direction opposite to the recording direction. Rotate the rotary developing device,
The intermediate position between the developing device and the adjacent developing device is set as the developing position.

[0010]

According to the present invention, when the developing device used for the development is moved from the developing position by rotating the rotary developing device after the completion of the development, the developing device has the end portion on the drying groove side. Is close to the recording medium, and the end on the side of the developing groove is far from the recording medium, so only the end on the side of the dry groove where almost no developer remains remains in contact with the recording medium. Does not stain.

[0011]

1 is a schematic perspective view showing the overall construction of an electrostatic recording apparatus used for carrying out the electrostatic recording method of the present invention.
In FIG. 1, 10 is a long electrostatic recording paper (recording medium), which is fed from a roll 11. 12 is an electrostatic recording paper 10
In the A direction (traveling direction during recording, that is, recording direction), a braking force is applied to the roll 11 and the B of the electrostatic recording paper 10 is applied.
It is a motor that rotationally drives the roll 11 during directional conveyance, that is, during rewinding. Reference numeral 13 is a winding roller for winding the electrostatic recording paper 10, and 14 is a motor for driving the roller. Although not shown, the roller for transporting the electrostatic recording paper 10 is provided at an appropriate position, like the conventional apparatus.

Reference numeral 15 is a recording head for forming an electrostatic latent image on the electrostatic recording paper 10 at the recording position, and 16 is a pad roller for pressing the electrostatic recording paper 10 against the recording head 15.

Reference numeral 18 is a rotary developing device for developing the electrostatic latent image on the electrostatic recording paper 10 at the same developing position by using developing liquids of black, cyan, magenta and yellow. This device basically has four developing units, that is, a developing unit 19a for black, a developing unit 19b for cyan,
The magenta developing device 19c and the yellow developing device 19d are arranged on the rotating body 20 at equal intervals in the circumferential direction, and have a structure similar to that shown in FIGS. Each developing unit has
A developer circulating system (not shown) that circulates a developer of a corresponding color is connected, and a rotating body drive system (not shown) that rotates the rotating body 20 and stops it at a predetermined position is connected to the rotating body 20. No) is connected. The rotation order of the rotating body 20 by this rotating body drive system will be described later.

Reference numeral 21 is an edge detector equipped with a line image sensor for detecting the edge of the electrostatic recording paper 10. Reference numeral 22 is a recording head 15 based on detection signals from the edge detector 21 and a mark detector (not shown). It is a control device that generates a recording timing cycle, controls the drive of the motors 12 and 14 and a conveyance roller (not shown), and controls the operation of the rotary developing device 18.

Next, an embodiment of the electrostatic recording method of the present invention using the electrostatic recording apparatus having the above structure will be described.

In the ready state before the start of recording, the developing device 1
As shown in FIG. 2A, the rotating body 20 of No. 8 is stopped at a position where the intermediate position between the yellow developing device 19d and the black developing device 19a is the developing position for the electrostatic recording paper 10. When performing recording, first, as shown in FIG. 2B, the rotating body 18 is rotated counterclockwise to move the black developing device 19a to the developing position and stop at that position. In this state, the electrostatic recording paper 10 in FIG.
Traveling in the direction (recording direction), the recording head 15 forms an electrostatic latent image of a black image, and the latent image forming position passes through the black developing device 19a and is developed by it.

When the recording and development of the black image are completed,
The rotating body 20 is rotated clockwise this time, that is, the developing device 19a used is moved in the direction opposite to the moving direction (direction of arrow A) of the electrostatic recording paper 10 at the time of recording.
As shown in (c), the intermediate position between the yellow developing device 19d and the black developing device 19a is the developing position for the electrostatic recording paper 10. As a result, the black developing device 19a that has been used up to now, as shown in FIG.
The 6 side is a position close to the electrostatic recording paper 10. In this state, the dry feed of the electrostatic recording paper 10 in the direction of arrow A and the rewinding in the opposite direction (direction of arrow B) are performed. Here, the end portion 27 of the developing device 19a on the side of the developing groove 24 immediately after use
The developer is often attached to the
Is greatly separated from the electrostatic recording paper 10, and only the drying groove 26 side where the developer is hardly adhered is the electrostatic recording paper 10.
Therefore, the residual developer of the developing device does not adhere to the image portion of the electrostatic recording paper 10 during the rewinding.

After the rewinding of the electrostatic recording paper 10 is completed, the rotating body 20 of the developing device 18 is rotated again in the counterclockwise direction, as shown in FIG.
As shown in (d), the cyan developing device 19b is positioned at the developing position and stopped. In this state, the electrostatic recording paper 10
Runs in the direction of arrow A, and a cyan image is recorded and developed. After that, the rotating body 20 of the developing device 18 is again rotated so that the developing device 19b being used moves in the direction opposite to the moving direction (direction of arrow A) of the electrostatic recording paper 10 at the time of recording. As shown in 2 (e), the black developing device 1
9a and the cyan developing device 19b at an intermediate position between the electrostatic recording paper 1
The development position is set to 0. Then, in that state, dry feed and rewinding are performed.

After that, as shown in FIG.
0 is rotated again in the counterclockwise direction and the magenta developing device 19
c is the developing position, and in that state, the electrostatic recording paper 10 shows the arrow A.
Traveling in the direction, recording and development of a magenta image are performed.
Thereafter, the same operation is repeated as shown in FIGS. 2G and 2H to record a yellow image. After the recording of the final color (yellow) is completed, as shown in FIG. 2 (i), the rotating body 20 is rotated clockwise so that the intermediate position between the magenta developing device 19c and the yellow developing device 19d becomes the developing position. To do. Then, in that state, dry feed and discharge in the direction of arrow A are performed. After that, as shown in FIG. 2 (j), the rotating body 20 is rotated in the clockwise direction to set the intermediate position between the yellow developing device 19d and the black developing device 19a as the developing position. As a result, the original ready state is restored. This completes one color image recording operation.

As described above, in the above steps, the developing device, which has completed the development, always moves in the direction opposite to the moving direction of the electrostatic recording paper 10 (direction of arrow A), and As shown in FIG. 3, the drying groove 26 side is close to the electrostatic recording paper 10 and almost no developer is attached to the drying groove 26 side. It is possible to obtain a good image without the residual developing solution of the developing device adhering to.

In the above embodiment, the black developing device 19a, the cyan developing device 19b, the magenta developing device 19c, and the yellow developing device 19d are arranged in this order in the clockwise direction on the rotating body 20 of the developing device 18. Although they are mounted side by side, the mounting order of the developing devices 19 can be appropriately changed.
FIG. 4 shows a case where the black developing device 19a, the yellow developing device 19d, the magenta developing device 19c, and the cyan developing device 19b are attached to the rotating body 20 in this order so as to be arranged in the clockwise direction. When the developing device having this arrangement is used, the rotary member 20 is initially set from the ready state in FIG.
Is rotated counterclockwise to position the black developing device 19a at the developing position [see FIG. 4 (b)] to record and develop a black image. Next, the rotating body 20 is rotated in the clockwise direction, and as shown in FIG.
9b and the developing device 19a for black are set to the developing position, the dry feed and the rewinding are performed, and then,
By rotating the rotator 20 clockwise, as shown in FIG. 4D, the cyan developing device 19b is set to the developing position to record and develop a cyan image. Hereinafter, the same operation is performed as shown in FIG.
After recording and developing the yellow image as shown in (f), (g), and (h), the rotating body 20 is moved clockwise as shown in FIG. Developing device 19
Dry feed and discharge are performed with the intermediate position between a and the yellow developing device 19d as the developing position. As described above, as shown in FIG. 4 (j), the original ready state is restored.

Even in the procedure shown in FIG. 4, the developing device, which has completed development, always moves in the direction opposite to the moving direction of the electrostatic recording paper 10 (the direction of arrow A), and therefore the developing device shown in FIG. As described above, the dry groove 26 side comes to a position close to the electrostatic recording paper 10 and almost no developer is attached to the dry groove 26 side. A good image can be obtained without the residual developer adhering. In the procedure shown in FIG. 4, the rotating body 20 always rotates in the clockwise direction except the first step, so that there is an advantage that the rotation control is easy.

[0023]

As is apparent from the above description, according to the present invention, the recording medium is moved in the recording direction with one of the plurality of developing devices provided in the rotary developing device being in the developing position. , Forming an electrostatic latent image on the recording medium by recording means and developing it with a developing device, and after recording is completed, an intermediate position between the developing device and an adjacent developing device is set to a developing position,
In the method of moving the recording medium in the direction opposite to the recording direction, after the development is completed, the developing device used for the development is rotated so as to move in the moving direction of the recording medium, that is, the direction opposite to the recording direction. Since the developing device is rotated and the intermediate position between the developing device and the adjacent developing device is the developing position,
At that time, in the developing device, the end on the dry groove side is close to the recording medium, and the end on the developing groove side is far from the recording medium.
Only the end on the dry groove side where almost no developer remains remains in contact with the recording medium, so that the recording medium is not contaminated by the remaining developer, and a good recorded image can be obtained. ing.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an example of an electrostatic recording device used for carrying out a method of the present invention.

FIG. 2 is a schematic side view illustrating a setting order of developing devices in the electrostatic recording apparatus.

FIG. 3 is a schematic cross-sectional view showing an enlarged relationship between the electrostatic recording paper and the developing device in FIG. 2 (c).

FIG. 4 is a schematic side view illustrating a setting order of developing devices in another embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view showing a rotary developing device used in a conventional electrostatic recording device in a state of being developed.

6 is a schematic cross-sectional view showing the rotary developing device shown in FIG. 5 in a state of rewinding electrostatic recording paper after completion of development.

FIG. 7 is a schematic side view illustrating a setting order of developing devices in a conventional electrostatic recording device.

[Explanation of symbols]

 10 Electrostatic Recording Paper 11 Roll 15 Recording Head 16 Pad Roller 18 Rotary Developing Device 19a, 19b, 19c, 19d Developing Device 20 Rotating Body

Claims (1)

Claim: What is claimed is: 1. A transporting unit that reciprocally moves a recording medium through a recording position and a developing position; a recording unit that forms an electrostatic latent image on the recording medium at the recording position; In an electrostatic recording apparatus having a plurality of developing devices attached to the body and a rotary developing device that moves a desired developing device to the developing position by rotation of a rotating body, one developing device is in the developing position The recording medium is moved in the recording direction, an electrostatic latent image is formed on the recording medium by the recording means, and the electrostatic latent image is developed by a developing device. After the recording is completed, the developing device moves the recording medium during recording. The rotary developing device is rotated so as to move in the direction opposite to the direction so that the intermediate position between the developing device and the adjacent developing device becomes the developing position, and in that state, the recording medium is reversed from the recording direction. Recording medium The image forming area is pulled back to the front of the recording means, and thereafter the operation of rotating the rotary developing device to bring the next developing device to the developing position is repeated to form a color image. ..