JPH10161430A - Electrostatic recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic recorder capable of sucking liquid toner by sufficiently producing negative pressure with a sucking part, ever if a recording medium has damage such as a cut and a fold. SOLUTION: A toner sucking part 51 sucking/recovering the liquid toner is constituted of plural sucking chambers 56a, 56b and 56c and plural sucking pumps 55a and 55b. A part in which a required image is finally recorded is sucked by the sucking chamber 56a and the sucking pump 55a and the other part is sucked by using the residual chambers 56b and 56c and the sucking pump 55b. By such a constitution, even if the liquid toner remains because the negative pressure can not be obtained in the sucking chambers 56b and 56c, due to the existence of the damage of the end part of the recording medium 1, the finally required image part can be sucked without any influence of the remaining of the liquid toner, in the sucking chamber 56a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic recording apparatus for forming an electrostatic latent image on a recording medium and developing it with a liquid toner, and more particularly, to suctioning excess toner after developing the electrostatic latent image. To a suction device.

[0002]

2. Description of the Related Art An electrostatic recording apparatus forms an electrostatic latent image on a recording medium with an electrostatic recording head, and then develops the image with a liquid toner in a developing section to obtain an image.
Hereinafter, the structure of a general electrostatic recording device will be described with reference to FIG. FIG. 4 is a diagram showing an electrostatic recording head for forming an electrostatic latent image of the electrostatic recording apparatus and a part of a development processing unit for developing the same. The recording medium 1 wound in a roll shape is first formed with an electrostatic latent image in the electrostatic recording head 2 while moving in the direction of the arrow shown in the figure, and then is conveyed to the development processing unit 3. The electrostatic recording head 2 is composed of a needle-shaped main electrode (not shown) and an auxiliary electrode provided in the vicinity thereof, and discharges between the electrodes corresponding to each pixel of the image data to charge the recording medium 1. Let it. The recording medium 1 that has passed through the electrostatic recording head 2 is
2 is applied. The liquid toner 32 is obtained by dissolving toner particles in a solvent such as Isopar, and the toner particles are charged to a polarity opposite to that of the electrostatic latent image on the recording medium 1. Therefore,
The toner particles applied on the recording medium 1 by the toner roller 31 are attracted to the electrostatic latent image by the electrostatic force, and adhere to the surface layer on the recording medium 1 by the electrostatic force to develop the electrostatic latent image.

[0003] The recording medium 1 after the development is removed from the toner suction unit 5 in order to remove excess liquid toner 32 remaining on the surface.
After the liquid toner 32 is sucked, the solvent is dried and removed by passing through the drying device 4. FIG. 5 is a perspective view of the toner suction unit 5. The toner suction unit 5 includes a vacuum channel 51, a vacuum hose 52, and a vacuum pump 5.
The suction is performed by applying a negative pressure to the groove portion 54 of the rectangular parallelepiped of the vacuum channel 51 by the vacuum pump 53. Groove portion 54 of vacuum channel 51
Is formed with a width smaller than the recording width of the recording medium 1, and
A vacuum hose 52 is connected to a hole penetrating the bottom portion. Since the groove portion 54 is formed with a width smaller than the entire width of the recording medium 1, the groove portion 54 is formed by the recording medium 1.
Is sealed and a negative pressure is obtained.

The recording medium 1 on which the development has been completed is moved in the direction of the arrow in FIG.
2 is sucked and removed, and the sucked liquid toner 32 is once collected and used again for development. However, the recording medium 1 may be damaged when transported or loaded into an electrostatic recording device. The damage is generally considered to be a cut or a fold at the end of the recording medium 1. In this case, a gap is formed between the recording medium 1 in which the groove portion 54 is sealed and the groove portion 54, so that air enters through the gap and a negative pressure cannot be obtained. As a result, FIG.
As shown in (1), in the recording medium 1, the liquid toner 32 remains on the surface of the recording medium 1 without suction of the entire recording width at a portion where the edge is damaged, and a desired image is obtained. Absent.

FIG. 6 shows a single-pass type color electrostatic recording apparatus. The same components as those in FIG. 4 are denoted by the same reference numerals. FIG. 4 shows only one set of the electrostatic recording head 2 and the development processing unit 3 and the like. However, in FIG. 6, since the electrostatic recording heads 2a and the like for four colors are provided, it is possible to carry Images can be obtained. Generally, a color image is obtained by superimposing four colors of cyan, magenta, yellow, and black. First, black is recorded, and then the other three colors are sequentially superimposed. This is for recording a positioning mark called a tick mark on the end of the recording medium 1. After a tick mark is recorded in black, the timing of superimposing another color is measured by detecting the tick mark, and each color can be recorded at a predetermined position. The tick mark at the end is finally cut off, and only an image portion is obtained.

[0006] The toner roller 31 of the development processing unit 3 is used to generate a tick mark at the end of the recording medium 1.
The liquid toner 32 is applied to the entire width of the recording medium 1. However, as described above, the vacuum channel 51 of the toner suction unit 5 sucks only the area narrower than the width of the recording medium 1, so that the outside is not sucked. If the liquid toner 32 applied by the toner roller 31 is not sucked by the vacuum channel 51, the liquid toner 32 adheres to the electrostatic recording head of the next color, and causes contamination of the head. At this time, if moisture remains in the liquid toner 32 on the surface of the recording medium 1, the liquid toner 32 moves toward the center of the width of the recording medium 1 in the gap between the recording medium 1 and the electrostatic recording head 2 by capillary action. Permeates. When the penetrated liquid toner 32 hits the tick mark or further reaches the image portion, color matching could not be performed, and image stains occurred.

If the width of the electrostatic recording head 2 is made slightly smaller than the width of the recording medium 1 so that the remaining liquid toner 32 does not adhere to the electrostatic recording head 2, A fold occurs in the recording medium 1 at the corner, which may cause the suction in the vacuum channel 51 to be disabled as described above.

[0008]

As described above, in the conventional electrostatic recording apparatus, the liquid toner 32 could not be sucked due to damage such as a cut or a fold at the end of the recording medium 1.
Further, when the liquid toner 32 after development is sucked, the liquid toner 32 attached to the end of the recording medium 1 is not sucked by the vacuum channel 51, so that it penetrates into the gap between the recording medium 1 and the electrostatic recording head 2. In some cases, tick marks for color matching and images were stained.

The present invention provides an electrostatic recording apparatus which can generate a sufficient negative pressure in the vacuum channel 51 to suck the liquid toner 32 even if the recording medium 1 is damaged such as a cut or a fold. The purpose is to: A second object of the present invention is to prevent the liquid toner 32 applied by the toner roller 31 from remaining on the extreme end of the recording medium 1 which cannot be suctioned due to the structure of the suction unit 5 and contaminate the surface of the recording medium. In other words, the present invention is to apply an electrostatic recording device capable of performing the above.

[0010]

According to a first aspect of the present invention, there is provided an electrostatic recording apparatus for forming an electrostatic latent image on a recording medium and developing the electrostatic latent image. A developing means, and a toner suction means for sucking and collecting the liquid toner adhering to the recording medium after the development is performed by the developing means, wherein the toner suction means is provided with a suction unit comprising a plurality of suction chambers, It is characterized by comprising a pump.

Another feature of the present invention is that suction is performed by a suction pump through an opening formed at the bottom of the suction section. According to another feature of the present invention, the suction section is formed in one groove shape divided into three suction chambers in the width direction of the recording medium, and the center suction chamber of the three suction chambers has suction on both sides. It is characterized by being larger than the room.

Another feature of the present invention is that the suction section is formed in one groove shape divided into three suction chambers in the width direction of the recording medium, and a central suction chamber among the three suction chambers is provided. The suction pump is provided to be larger than the suction chambers on both sides, and the suction pump includes a first suction pump for suctioning the suction chamber in the center and a second suction pump for sucking suction chambers on both sides. is there.

A still further feature of the electrostatic recording apparatus of the present invention is that an electrostatic recording head is provided with a toner discharge groove on a surface which is in sliding contact with a recording medium. According to a further feature of the present invention, the toner discharge groove is formed on a surface of the electrostatic recording head which is in sliding contact with the recording medium, and is used for recording an alignment mark on the recording medium or an image to be finally output. The recording medium is located outside the width direction of the recording medium from the portion where it is located.

Another feature of the present invention is that the toner discharge groove is formed on both sides in the width direction of the recording medium on the surface of the electrostatic recording head which is in sliding contact with the recording medium.
Further features of the electrostatic recording apparatus of the present invention include: an electrostatic recording head for forming an electrostatic latent image on a recording medium; a developing unit for developing the electrostatic latent image; A toner suction means for sucking and collecting the liquid toner adhering to the recording medium, and forming a toner discharge groove at both ends of a surface of the electrostatic recording head in sliding contact with the recording medium, in the same direction as the recording medium travel direction. The toner discharge groove is formed on the surface of the electrostatic recording head that is in sliding contact with the recording medium, and is positioned in the width direction of the recording medium from a position where an alignment mark or a finally output image is recorded on the recording medium. The toner suction means, which is located on the outside, comprises a single groove-shaped suction portion partitioned into a plurality of portions, and a suction pump.

With the above-described configuration, the electrostatic recording apparatus of the present invention is capable of maintaining the liquid toner remaining during development even if damage such as a cut or a fold exists at the end of the recording medium. It is possible to prevent leakage of the air to be sucked in the suction unit for sucking the ink, and to eliminate the suction error of the suction unit due to the damage of the recording medium. Further, with the above configuration, the liquid toner adhering to the end of the recording medium that could not be sucked by the suction unit does not penetrate between the recording medium and the electrostatic recording head, thereby preventing the image forming area from being stained. be able to.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing the vicinity of an electrostatic recording head and a developing section of an electrostatic recording apparatus according to the present invention. The recording medium 1 is conveyed in the direction of the arrow in the drawing, and an image is sequentially formed. The edge 11 of the recording medium 1 is narrower in the width direction of the recording medium 1 than the electrostatic recording head 2 and is always in sliding contact with each other. Does not occur. The electrostatic recording apparatus according to the present embodiment is a single-pass type color electrostatic recording apparatus. Therefore, a plurality of electrostatic recording heads 2 are provided as shown in FIG. Although not shown in the figure, a plurality of development processing units and the like exist in pairs with the electrostatic recording head. The figure also shows a cross-sectional view of portions A and B.

The electrostatic recording head 2a is an electrostatic recording head of a color for which recording is performed first among a plurality of electrostatic recording heads 2. Assume that the color is black. First, image information corresponding to black of an input image is input to the electrostatic recording head 2a, and a discharge is generated between a needle-shaped main electrode (not shown) and the auxiliary electrode 22 on the electrostatic recording head 2a, thereby causing the recording medium 1 to be discharged. An electrostatic latent image corresponding to black is formed on the recording surface.

Next, the recording medium 1 that has reached the toner roller 31 is coated with the black liquid toner 32 over the entire width of the paper. The toner particles applied on the recording medium 1 by the toner roller 31 are attracted to the electrostatic latent image by electrostatic force, and adhere to the surface on the recording medium 1 to develop the electrostatic latent image. After the development, the recording medium 1 sucks the liquid toner 32 through the vacuum channel 51 in order to remove the excess liquid toner 32 remaining on the surface. FIG. 2 is a diagram showing the vacuum channel 51 in detail, and FIG. 3 is a perspective view thereof. The lower part of FIG. 2 is a sectional view of the part A. The vacuum channel 51 has a groove formed in a rectangular parallelepiped housing, and is constituted by three suction chambers 56a, 56b, and 56c by four partitions 52. Suction chamber 5
6a is provided slightly larger than the finally required image width. Therefore, the liquid toner 3 remaining in the image portion
2 are all sucked in the suction chamber 56a.

The suction chambers 56b and 56c are provided on both sides of the suction chamber 56a, and a partition 52 at an end of the suction chamber 56a is provided.
And a partition 52 slightly inside the end of the recording medium 1. What is sucked here is the liquid toner remaining when the tick marks for alignment of the four color images used for generating the color image are recorded. Liquid toner remaining in portions outside the suction chambers 56b and 56c is hardly sucked.

The suction in the suction chamber 56 utilizes a negative pressure generated by suction by the suction pump 55. Suction pump 5
5 is connected to the suction chamber 56 through an opening 53 formed at the bottom of the suction chamber 56 and a suction pipe 54. Here, the suction pump 55 is connected to the suction pump 55 connected to the suction chamber 56a.
a and a suction pump 5 connected to the suction chambers 56b and 56c.
5b are provided. With this structure, the suction pump 55a can suck only the liquid toner 32 remaining in the finally required image portion, and the suction pump 55b can suck only the liquid toner 32 near the ends of the recording medium 1 on both sides. .

The vacuum channel 51 having such a structure
Then, if the recording medium 1 having a damaged end portion is conveyed, a gap is formed between the recording medium 1 and the vacuum channel 51, so that air leaks from the gap and causes the suction chamber 56b or the suction chamber 56c. Cannot obtain negative pressure. However, the suction chamber 56a where an image is formed is
Partition 52 between suction chamber 56b and suction chamber 56c
Is provided, the sealed state is maintained, and since the suction pump 55a is connected only to the suction chamber 56a, a negative pressure is obtained and suction can be performed.

It is conceivable that the recording medium 1 may be damaged so much that it reaches the suction chamber 56a and a negative pressure cannot be obtained.
In that case, it is the case that the damage has been reached to the image portion, and it is practically the range that could not be used originally. FIG. 3 shows a state of the recording medium 1 when the recording medium 1 having a break at the end is conveyed and suction is performed by the vacuum channel 51. Since a negative pressure cannot be obtained at the cut portion, the liquid toner 32 remaining after the development is not removed. In this embodiment, the suction chambers 56b and 56c on both sides are suctioned by one suction pump 55b. Therefore, if a negative pressure is not obtained in one suction chamber 56, a negative pressure is not obtained in another suction chamber 56, and as a result, the liquid toner 32 remains on both ends of the recording medium 1 as shown in FIG. . Each suction chamber 56b, 5
If the suction pump 55 is provided for each 6c, it is possible to prevent negative pressure from being obtained only on one side.

Next, when the suction of the residual liquid toner 32 in the vacuum channel 51 of FIG.
After the drying operation, the electrostatic recording head 2 of the next color
b. At this time, the both ends in the width direction of the recording medium 1 not sucked by the vacuum channel 51 are:
Despite the drying operation, the liquid toner 32 may remain. In this case, in the conventional electrostatic recording apparatus, the liquid toner penetrates between the electrostatic recording head 2b of the next color and the recording medium 1 due to a capillary phenomenon, and the surface of the recording medium 1 becomes dirty.

In the electrostatic recording head 2a of the electrostatic recording apparatus according to the present embodiment, a toner discharge groove 23 is formed on a part of the surface that comes into sliding contact with the recording medium 1. The toner discharge groove 23 is provided outside the position corresponding to the tick mark position formed on the recording medium 1, that is, further outside the outermost electrode. The liquid toner 32 at the end of the recording medium 1 that has not been removed by the vacuum channel 51 is
It adheres to the electrostatic recording head 2b and spreads by capillary action between the recording medium 1 and the recording medium. However, unlike the conventional electrostatic recording head 2, the liquid toner that has reached the toner discharge groove 23 does not spread to the image portion any more.

When the color image is finally recorded, the recording medium 1 is located outside the unnecessary tick mark.
Disconnected from

[0026]

As described above, in the electrostatic recording apparatus of the present invention, the partition is provided in the suction chamber of the vacuum channel of the suction section for suctioning the excess liquid toner remaining on the surface of the recording medium after the development processing. Since the suction system is changed between the part that finally outputs as an image and the part that does not, the part that finally outputs as an image even if a recording medium that has damage such as cuts or folds is used. Can be performed normally, and a desired image can be obtained.

Further, in the electrostatic recording apparatus of the present invention, since the toner discharging groove is provided in the electrostatic recording head, even if the liquid toner adheres to the end of the recording medium and is conveyed, the liquid toner is used as an image. It does not penetrate to the part, so that the stain on the image part can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic view of the vicinity of an electrostatic recording head of an electrostatic recording apparatus according to an embodiment of the present invention.

FIG. 2 is a detailed view (a plan view and a sectional view) of a vacuum channel of the electrostatic recording device of the present invention.

FIG. 3 is a perspective view of a vacuum channel of the electrostatic recording device of the present invention.

FIG. 4 is a schematic view showing the vicinity of an electrostatic recording head of a conventional electrostatic recording device.

FIG. 5 is a perspective view of a vacuum channel of a conventional electrostatic recording device.

FIG. 6 is a schematic view of a single-pass type color electrostatic recording apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording medium 2, 2a, 2b Electrostatic recording head 3 Developing part 4 Drying device 5 Suction part 11 Recording medium edge 22 Auxiliary electrode 23 Toner discharge groove 31 Toner roller 32 Liquid toner 51 Vacuum channel 52 Partition 53 Opening 54 Suction pipe 55 Suction pump 56 Suction chamber

Claims (8)

[Claims] An electrostatic recording device that forms an electrostatic latent image on a recording medium; a developing unit that develops the electrostatic latent image; and a developing unit that develops the electrostatic latent image. An electrostatic recording apparatus comprising: a toner suction unit that suctions and collects liquid toner adhering to a recording medium; wherein the toner suction unit includes a suction unit including a plurality of suction chambers and a suction pump. . 2. The electrostatic recording apparatus according to claim 1, wherein the suction unit performs suction by the suction pump from an opening formed in a bottom part. 3. The suction section has a single groove shape partitioned into three suction chambers in the width direction of the recording medium, and a central suction chamber among the three suction chambers is larger than suction chambers on both sides. The electrostatic recording device according to claim 1, wherein: 4. The suction section has a single groove shape partitioned into three suction chambers in the width direction of the recording medium, and a central suction chamber of the three suction chambers is provided to be larger than suction chambers on both sides. The suction pump according to claim 1, wherein the suction pump includes a first suction pump that sucks a suction chamber in a center, and a second suction pump that suctions suction chambers on both sides. Electrostatic recording device. 5. An electrostatic recording apparatus according to claim 1, wherein a toner discharge groove is formed on a surface of said electrostatic recording head which is in sliding contact with said recording medium. 6. The toner discharge groove is formed on a surface of the electrostatic recording head that is in sliding contact with the recording medium, and is used for recording a positioning mark on the recording medium or an image to be finally output. 6. The electrostatic recording apparatus according to claim 5, wherein the recording medium is located outside the recording medium in a width direction of the recording medium. 7. The recording medium according to claim 1, wherein the toner discharge groove is formed on both sides of the electrostatic recording head in sliding contact with the recording medium in both directions in the recording medium width direction and in parallel with the recording medium advancing direction. The electrostatic recording device according to claim 5. 8. An electrostatic recording apparatus, comprising: an electrostatic recording head for forming an electrostatic latent image on a recording medium; a developing means for developing the electrostatic latent image; A toner suction unit that suctions and collects liquid toner adhering to the recording medium, and at both ends of a surface of the electrostatic recording head that slides on the recording medium,
Form a toner discharge groove in the same direction as the recording medium travel direction,
The toner discharge groove is formed on the surface of the electrostatic recording head that is in sliding contact with the recording medium, and is positioned in the width direction of the recording medium from a position where an alignment mark on the recording medium or a finally output image is recorded. Wherein the toner suction means comprises a single groove-shaped suction section divided into a plurality of sections, and a suction pump.