JPS6238484A - Recording device - Google Patents

Abstract

PURPOSE:To prevent recording paper from useless consumption at the time of no recording by arranging an image forming medium so as to abut it upon a recording paper carrying means. CONSTITUTION:At the time of no transfer, a transfer drum 60 is separated from respective recording units 67, 70. A test cycle is formed before actual recording and the recording units are driven to check whether respective parts of respective recording units are normally functioned or not. Simultaneously, the characteristics of a photosensitive drum and a developer are stabilized to prepare recording. The 2nd recording unit 70 is moved so as to be contacted with a transfer drum around which recording paper is wound by using a motor 72 and a feed screw at the time of transfer, and at the end of recording, the 2nd recording unit 70 is separated from the transfer drum. Consequently, the recording paper can be prevented from useless consumption at the time of no recording and the photosensitive drum can be prevented from damage and friction.

Description

[Detailed Description of the Invention] [Summary of the Invention] A recording device that uses a plurality of photoreceptors in an electrophotographic process, in which the positioning of the recording paper and the image formed on the photoreceptor is accurate, and the recording paper is not wasted. Prevent use.

[Industrial application field]

The present invention relates to a recording device using an electrophotographic process, and particularly to a transfer device that can perform accurate positioning.

[Conventional technology and problems]

A recording device proposed by the present inventors as a multicolor recording method using an electrophotographic process (Japanese Patent Application No. 16051/1983)
I will explain about it.

FIG. 2 shows the configuration of a multicolor recording apparatus. As shown in FIG. 2, this multicolor recording device arranges two two-color recording units that form two-color toner images on a photosensitive drum, and sequentially transfers the toner images onto recording paper. It is a recording device that can obtain images.

Hereinafter, a method for forming two-color toner images on the photosensitive drum 101 will be explained using FIG. 3, which shows the surface potential of the photosensitive drum, and FIG. 4, which shows the triboelectric charging series of carrier and toner.

The photosensitive drum 101 is charged using the initial charger 102 as shown in FIG.
As shown in 1), it is uniformly charged. Thereafter, negative exposure (first exposure) is performed by the first exposure device 103 using a semiconductor laser, and an electrostatic latent image shown in FIG. 3(2) is formed. Next, reversal development is performed in the first developing device 104 having the toner of the first color, and a first toner image is formed on the photosensitive drum as shown in FIG. 3(3).

Next, recharging is performed using the recharging device 105, as shown in FIG. 3 (4).
Make the potential on the photosensitive drum uniform as shown in .

Next, negative exposure (second exposure) is performed using the second exposure device 106.
The electrostatic latent image shown in FIG. 3 (5) is formed.

Next, reversal development is performed using the second developing device 107 having toner of the second color to obtain a two-color toner image on the photosensitive drum, as shown in FIG. 3(6).

In this second development, a soft-touch development method that does not destroy the first toner image on the photosensitive drum is applied.

For example, a microcarrier development method in which the carrier particle size is reduced to 5 to 100 μm, or a non-contact development method in which an alternating current bias voltage is applied to a developing device to cause toner to fly from the developer for development is used.

The two-color toner images on the photoreceptor are transferred all at once onto a recording paper 112 by a transfer corotron 108 in a transfer section.

Thereafter, the photosensitive drum 101 is charged with a static eliminator 109 to remove residual toner, and is cleaned with a cleaner 110.
Further, the static electricity is removed by an optical static eliminator 111, and it is used repeatedly.

In this conventional method, in order to prevent color mixing of the second toner image caused by the first toner getting mixed into the second developing device and accumulating, a method was also proposed in which the first toner is separated from the second developer. (Refer to Japanese Patent Application Laid-open No. 105713/1983)
In this method, the triboelectric charging series of carrier and toner is
Select as shown. The first toner and the second toner are each a first carrier.

It is charged to a positive polarity by frictional charging with the second carrier.

However, when the first toner mixes with the second developer, the polarity is reversed due to frictional electrification with the second developer, and becomes negative polarity or approximately O. The first toner of negative polarity is electrostatically combined with the second toner of positive polarity, and the apparent charge amount is approximately O. As a result, the binding force with the carrier is weakened, and the first. The first toner, which remains electrostatically bound to the second toner or whose charge amount is approximately zero, is scattered and separated from the sleeve of the developing device by centrifugal force. Therefore, the first toner does not accumulate in the second developing device, and good development can be stably performed.

Although image formation on the photosensitive drum 101 has been described above, two-color toner images can be formed on the photosensitive drum 201 in the same manner.

In this case, by setting the toner of the third developing device 204 and the fourth developing device 207 to a different color from the toner of the first developing device 104 and the second developing device 107, multi-color recording can be performed. can. In FIG. 2, 202 is an initial charger, 203 is a third exposure device, 205 is a recharging device, 206 is a fourth exposure device, 208 is a transfer corotron, 209 is a corona static eliminator, 210 is a cleaner, and 211 is a photo static eliminator. are shown respectively.

Next, a method of transferring the image from the photosensitive drum to the recording paper will be explained. FIG. 2 shows a case where a belt 301 is used to convey recording paper. Recording paper 112 is conveyed by a belt and contacts photoreceptor 101 at a transfer portion. Corona irradiation is performed from the back side of the recording paper with a transfer corotron 108,
The toner image on the photoreceptor 101 is transferred. Subsequently, the recording paper is conveyed by a belt, and the toner image on the photosensitive drum 201 is transferred in the same manner as on the photoreceptor 101, so that a multicolor toner image is obtained on the recording paper.

Next, the toner is melted and fixed by the fixing device 302 to obtain a permanent multicolor recorded image. 303 is a delivery roller.

However, when recording at a high resolution such as 20 dots/mm, the toner images on the photosensitive drum 101 and the toner image on the photosensitive drum 201 are transferred respectively by conveying the paper using the belt or roller. Accurate positioning on the recording paper is difficult due to uneven feeding of the recording paper and partial stretching of the recording paper. If such a positional shift of the toner images of each color occurs, the quality of the recorded image will be significantly degraded, such as image disturbance and two-color unevenness.

Therefore, the inventors of the present invention proposed in Japanese Patent Application No. 124273/1988 that accurate positioning can be performed by using a transfer drum to which recording paper is brought into close contact.

FIG. 5 shows the configuration of the recording device. Around the photosensitive drum 1, there are an initial charger 2, a first exposer 3, a first developer 4, a recharger 5, a second exposer 6, a second developer 7, a static eliminator 8, a cleaner 9, and an optical static eliminator. 10 are arranged. Similarly,
An initial charger 12 and a third exposure device 1 are also provided around the photosensitive drum 2.
3, third developing device 14, recharging device 15, fourth exposing device 16,
A fourth developing device 17, a static eliminator 18, a cleaner 19, and an optical static eliminator 20 are arranged. On these two photosensitive drums,
According to the method described above, toner images of each two colors are formed.

A transfer drum 21 is provided so as to be in contact with these two photosensitive drums. As shown in FIG. 6, the transfer drum 21 has a screen mesh in the area around which the recording paper is wound. A recording paper 25 is wound around the transfer drum 21, and rotates at the same peripheral speed as the photosensitive drums 1 and 11.

At a transfer portion where the photosensitive drum 1 and the transfer drum are in contact, a transfer corotron 22 irradiates the recording paper with corona through a screen mesh, thereby transferring a toner image. Further, at the portion in contact with the photosensitive drum 2, the transfer corotron 23
Corona irradiation is performed on the recording paper through the screen mesh, and the toner image on the photosensitive drum 2 is transferred to the recording paper.

The toner on the recording paper is fused and fixed by a fixing device 24, and sent out by a delivery roller 26. The roller 27 is used to apply back tension so that the recording paper comes into close contact with the transfer drum.

Here, as a method of aligning the circumferential speeds of the photosensitive drum 1, the photosensitive drum 11, and the transfer drum 21, there is a method using a belt and a pulley as shown in FIG.

A pulley 30 directly connected to the rotating shaft of the photosensitive drum 1, a pulley 32 directly connected to the rotating shaft of the photosensitive drum 11, three pulleys directly connected to the shaft of the transfer drum, and an idle pulley 3.
4 is driven by a driving pulley 33 using a timing belt 35. By making the diameter ratio of the photosensitive drum pulley and the transfer drum pulley the same as the diameter ratio of each drum, the circumferential speed of all drums can be made the same.
It is possible to prevent deterioration of the recorded image, color unevenness, etc. due to misalignment of the four-color toner images on the recording paper. For more precise positioning, photosensitive drums 1 and 11, transfer drum 2
A servo motor is used for all drums, and electrical control is performed so that the three drums have the same circumferential speed. By doing so, accurate positioning becomes possible, and more accurate recording can be performed.

However, when actually using a printer, there are times when you want to rotate the photosensitive drum without performing transfer (for example, when you want to rotate the photosensitive drum as a dummy without exposing it to stabilize the characteristics of the photosensitive drum and developer, or when performing maintenance. In such cases, if the recording paper is conveyed in accordance with the circumferential speed of the photosensitive drum, there is a drawback that the recording paper is wasted. In addition, if the conveyance of the recording paper is stopped and the photoconductor drum is rotated, the photoconductor drum will be rubbed by the recording paper, causing damage to the surface of the photoconductor drum and causing wear, which will shorten the life of the photoconductor drum. There are drawbacks.

An object of the present invention is to provide a recording apparatus in which recording paper is not wasted when recording is not actually performed, such as during a test cycle.

[Means for solving problems]

According to the present invention, the above-mentioned problem can be solved in a recording apparatus that performs transfer by keeping the circumferential speed of a plurality of image forming media and the conveying speed of a recording paper conveying means in close contact with a plurality of image forming media to be the same. The problem is solved by a recording device that is characterized in that it can come into contact with a recording paper conveyance means.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a schematic diagram illustrating an embodiment of a recording apparatus according to the present invention.

Inside the first recording unit 67, there is a first photosensitive drum 40, and around the photosensitive drum 40 there is an initial charger 41, a first exposure device 42, a first developing device 43, a recharging device 44, a second exposure device 45. , a second developing device 46, a static eliminator 47, a cleaner 48, and an optical static eliminator 49 are arranged.

Further, there is a second photosensitive drum 50 inside the second recording unit 1-70, and an initial charger 5 is provided around the photosensitive drum 50.
1, third exposure device 52, third developing device 53, recharging device 54,
A fourth exposing device 55, a fourth developing device 56, a static eliminator 57, a cleaner 58, and an optical static eliminator 59 are arranged.

Further, a recording paper 63 is wound around the transfer drum 60, and a first transfer corotron 61 and a second transfer corotron 62 are arranged inside the transfer drum 60.

Furthermore, 65 is a fixing device, 66 is a feed roller, 6
A roller 4 applies back tension to bring the recording paper into close contact with the transfer drum 60.

The first recording unit 67 is supported by a linear bearing (not shown) and is installed so as to be movable in a direction in which it comes into contact with the transfer drum 60. Further, 68 is a feed screw, which is rotated by a motor 69 to move the first recording unit 67.
It makes contact with and separation from the transfer drum 60. Similarly, the second recording unit 70 is brought into contact with and separated from the transfer drum 60 by a feed screw 71 and a motor 72.

2 on each of the first photosensitive drum 40 and the second photosensitive drum 50.
The method for obtaining color toner images is the same as the conventional method described above.

The operation of the parts related to the present invention will be explained below.

When not performing transfer, the transfer drum 60 and each recording unit 67 and 70 are separated. Before actually recording, a test cycle is set up in which the recording units are operated to check whether each part of each recording unit is functioning properly.

At the same time, the characteristics of the photosensitive drum and the characteristics of the developer are stabilized in preparation for recording. At this time, since each recording unit and the transfer drum are separated, there is no need to rotate the transfer drum, and no recording paper is wasted.

Next, the case where a recording operation is actually performed will be explained with regard to the first recording unit. The photosensitive drum 4 is recorded using the first recording unit.
At the same time as the formation of a toner image on the recording paper 63 starts, the transfer drum 60 around which the recording paper 63 is wound starts to rotate. After making the circumferential speed of the transfer drum 60 the same as the circumferential speed of the photosensitive drum 40, the motor 69 is used to rotate the feed screw 68, and the first Move the recording unit. At the same time, using the transfer corotron 61, corona irradiation is performed from the transfer drum side.
The toner image on the photosensitive drum 40 is transferred to recording paper.

When recording is finished, the transfer corona irradiation is stopped, and the motor 69 is used to rotate the feed screw 68 in the opposite direction to that at the start of recording, so that the photosensitive drum 4 is moved from the recording paper wound around the transfer drum.
The first recording unit is moved so that 0 is separated. Thereafter, the rotation of the transfer drum 60 and the photosensitive drum 40 is stopped.

Similarly to the first recording unit, when performing transfer, the second recording unit 70 is moved using the motor 72 and the feed screw 71 so as to come into contact with the transfer drum on which recording paper is wound. .

Similarly, at the end of recording, the second recording unit is separated from the transfer drum.

By performing such an operation, the photosensitive drum and the recording paper come into contact only when the photosensitive drum is rotating at the same circumferential speed as the recording paper, which prevents damage caused by the photosensitive drum being rubbed by the recording paper. Wear can be eliminated.

A servo motor is used to rotate the photosensitive drum and the transfer drum, and during transfer, the circumferential speeds are electrically controlled to be the same. In addition, when performing multicolor recording by overlapping four color toner images, the accuracy of positioning each toner image is a problem, but since the transfer is performed with the recording paper in close contact with the transfer drum, the accuracy of the transfer position is It is possible to obtain records with good positional deviation. Note that alignment of the two color toner images on the same photosensitive drum can be performed relatively easily by using a detection means such as a rotary encoder for the rotational position of the photosensitive drum. Of course, it is necessary to change the exposure timing for each exposure device in consideration of the difference in the position of the exposure device and the difference in the transfer position, but this control can be easily performed.

Furthermore, if the two-color toner of the first recording unit is sufficient for recording, the second recording unit does not need to be brought into contact with the transfer drum and does not need to be operated.
This has the advantage of extending the life of each part of the second recording unit. Conversely, if recording can be performed only with the second recording unit, there is no need to operate the first recording unit.

Further, when loading recording paper, it is necessary to rotate the transfer drum, but the recording unit does not need to be operated at this time either.

Furthermore, when performing maintenance, each recording unit and transfer drum section can be inspected separately, which is convenient.

In the above embodiment, a motor and a feed screw are used as means for moving the recording unit, but other methods such as a cam, a solenoid, etc. may also be used.

Also, although we have explained the case where there are two recording units,
A similar effect can be obtained even if the number is increased to three or more.

In the above embodiment, a screen mesh was used as the transfer drum to perform corona transfer. A similar effect can be obtained by using so-called roller transfer.

Furthermore, although the above embodiment uses a method in which the recording unit is moved and brought into contact with the transfer drum, it is also possible to use a method in which the recording unit is fixed and the transfer drum is moved and brought into contact with the recording unit. .

〔Effect of the invention〕

As explained above, according to the present invention, by bringing the photosensitive drum and the transfer drum wrapped with recording paper into contact during transfer, and keeping them apart at other times, the recording paper is wasted when recording is not actually performed. Never used. Further, damage and wear of the photosensitive drum can also be prevented.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, FIG. 2 is a schematic diagram explaining a multicolor recording device, FIG. 3 is a schematic diagram showing the potential on a photosensitive drum, and FIG. The figure shows a carrier,
FIG. 5 is a diagram illustrating the triboelectric charging system of toner, FIG. 5 is a diagram showing the configuration of a multicolor recording device using a conventional transfer method, FIG. 6 is a diagram showing a transfer drum, and FIG. is a photosensitive drum. FIG. 3 is a diagram illustrating a drive system of a transfer drum. 1... Photosensitive drum, 2, 12, 41, 51... Initial charger, 3,
13, 42... 1st n optical device, 4, 14, 43...
...First developing device, 5, 15, 44, 54... Recharging device, 6, 16, 45... Second exposure device, 7,
17, 46...second developing device, 8, 18, 47
, 57...Static eliminator, 9, 19, 48, 58...
・Cleaner, 10, 20, 49, 59... Optical static eliminator, 21, 60... Transfer drum, 22... Transfer corotron, 24, 65... Fixing device, 25
, 63... Recording paper, 26, 66... Feeding roller, 30, 31, 32... Pulley, 35... Timing belt, 33... Driving pulley, 40... First photosensitive drum , 50... Second photosensitive drum, 52... Third exposure device, 53... Third developing device, 5
5... Fourth exposure device, 56... Fourth developing device, 61
...First transfer corotron, 62...Second transfer corotron, 67...First recording unit, 68...Feed screw, 69...Motor, 70
...Second recording unit.

Claims (1)

[Scope of Claims] 1. In a recording apparatus that performs transfer at the same peripheral speed of a plurality of image forming media and the conveying speed of a recording paper conveying means in which recording paper is brought into close contact with the recording paper, the image forming medium is A recording device characterized in that it can come into contact with a conveying means. 2. The recording apparatus according to claim 1, wherein each image forming medium is provided with toner image forming means of two or more colors. 3. Claim 1, characterized in that a transfer drum is used as the recording paper conveyance means in which the recording paper is brought into close contact with the recording paper.
Recording device as described in section. 4. The recording apparatus according to claim 3, wherein the transfer drum is provided with a screen mesh. 5. The recording apparatus according to claim 3, wherein the surface of the transfer drum is a conductor. 6. The recording apparatus according to claim 1, wherein the image forming medium is provided with an image forming medium moving means for bringing the image forming medium and recording paper into contact with each other. 7. To bring the image forming medium and the recording paper into contact,
2. The recording apparatus according to claim 1, wherein said recording paper transport means is provided with a moving means. 8. To bring the image forming medium and the recording paper into contact,
2. The recording apparatus according to claim 1, wherein moving means is provided for both the image forming medium and the recording paper transport means.