JP4516223B2 - Printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printing machine that forms an image on the surface of a photosensitive drum with liquid toner and transfers the image onto a printing paper via a transfer roller.
[0002]
[Background]
2. Description of the Related Art Conventionally, there has been known a printing machine that forms an image with liquid toner on the surface of a photosensitive drum and transfers the image onto a printing sheet disposed between the transfer roller and a backup roller via a transfer roller. .
This printing machine includes a charger that charges the surface of the photosensitive drum to impart photosensitivity, an exposure device that exposes the photosensitive drum based on drawing data to create an electrostatic latent image, and an electrostatic on the photosensitive drum. A developing unit that develops the latent image, and the developing unit includes a developing roller that supplies liquid toner to the photosensitive drum.
[0003]
The liquid toner is supplied from the developing roller to the photosensitive drum by using electrophoresis that supplies the liquid toner by the difference between the voltage of the exposed portion of the photosensitive drum and the other surface and the voltage of the developing roller. Is called. That is, the developing roller and the photosensitive drum are brought close to each other to a predetermined distance, and when the distance between the developing roller and the photosensitive drum reaches a predetermined distance, the liquid toner moves from the developing roller to the photosensitive drum, thereby forming an image. It has become.
The distance between the two is determined by the operator based on experience and intuition in consideration of the rotational speed of the photosensitive drum, the rotational speed of the developing roller, the characteristics of the liquid toner, and the like.
Note that such a printing press can also be used as a proofreading printing press that performs proof printing.
[0004]
[Problems to be solved by the invention]
By the way, when liquid toner is supplied from the developing roller to the photosensitive drum and an image is formed on the surface of the photosensitive drum, if the distance between the developing roller and the photosensitive drum is too close, excessive liquid toner is supplied due to capillary action. Therefore, the image becomes unclear, and conversely, if the distance between the developing roller and the photosensitive drum is too long, the liquid toner cannot move and image formation is not performed.
On the other hand, the printed matter to be printed by the printing machine having the above-described configuration, for example, the size of the printing paper such as A1 size, A2 size, B1 size, or the thickness of the printing paper is different. There are various types according to needs. In the case of multicolor printing, all the colors are often superimposed one after another, and the thicknesses of these colors are also related. Therefore, the rotational speed of the photosensitive drum, the rotational speed of the developing roller, and the characteristics of the liquid toner each time different types of printing are performed. In accordance with the above, it is necessary to adjust the distance between the developing roller and the photosensitive drum to an optimum state in which the image is the clearest.
However, in the past, the operator has determined the distance between the developing roller and the photosensitive drum based on experience and intuition, so that there is a subtle difference in the print completion for each type of printing under different conditions. The problem of adversely affecting the image quality arises.
[0005]
An object of the present invention is to provide a printing machine capable of suppressing an influence on an image and maintaining a high image quality when an image is formed on the surface of a photosensitive drum using liquid toner.
[0006]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a photosensitive drum on which an image is formed, a charging unit for charging the surface of the photosensitive drum, and the surface of the photosensitive drum is exposed to electrostatic charge after charging by the charging unit. Exposure means for creating a latent image, development means for developing the electrostatic latent image on the surface of the photosensitive drum by supplying liquid toner to the surface of the photosensitive drum by electrophoresis after exposure by the exposure means, and the developing means A transfer roller for receiving the image after development by the image forming apparatus, a backup roller for transferring the image on the transfer roller to the printing paper, and each of these means and a control means for controlling each of the rollers. The means includes a developing machine main body that stores the liquid toner, and a developing roller that is provided in the developing machine main body and supplies the liquid toner to the photosensitive drum for development. The distance between the surface of the image roller and the surface of the photosensitive drum can be adjusted, and the transfer roller can be engaged with and disengaged from the photosensitive drum, and the backup roller can be engaged and disengaged from the transfer roller. And the transfer roller is disengaged from the photosensitive drum until the development of the photosensitive drum by the developing unit is completed, and the backup roller receives the printing paper from the transfer roller. The printing machine is characterized in that the mutual engagement is disengaged until it is arranged between the backup roller and the transfer roller .
[0007]
In the present invention, since the distance between the surface of the developing roller and the surface of the photosensitive drum can be adjusted, the rotational speed of the photosensitive drum, the rotational speed of the developing roller, and the liquid toner each time different types of printing are performed. The interval can be determined according to the characteristics of As a result, since the liquid toner can be supplied at an optimal interval at which the image is clear, the influence on the image can be suppressed and the image quality can be maintained at a high level.
In the present invention, the development of multicolor printing can be performed on the surface of the photosensitive drum without being obstructed by the transfer roller, and the printing paper can be fed without being obstructed by the backup roller. As a result, smooth printing can be performed.
[0008]
According to a second aspect of the present invention, in the printing machine according to the first aspect, the main body of the developing machine includes a plurality of toner storage chambers that store liquid toners corresponding to a plurality of printing colors, and the developing roller includes: Each of the plurality of toner storage chambers is provided.
[0009]
In the present invention, the liquid toner corresponding to the printing color can be stored for each color in the toner storage chamber, and a developing roller is provided in each storage chamber, so that multicolor printing can be performed without mixing the colors. Can meet the needs of diverse customers.
[0010]
According to a third aspect of the present invention, in the printing press according to the second aspect, the photosensitive drum and the transfer roller are formed to have the same diameter, and a drawing region where drawing is performed and a drawing are not performed, respectively. The developing machine main body and the developing roller corresponding to a predetermined printing color among the plurality of printing colors are moved within the non-drawing area of the photosensitive drum. Is.
[0011]
In the present invention, since the developing machine main body and the developing roller are moved using the non-drawing area, this movement does not affect the drawing, and the drawing of the next color can be quickly performed. Since the drawing area and the non-drawing area are provided, the size of the printing paper can be dealt with by changing the range of the non-drawing area. Accordingly, a single photosensitive drum and transfer roller can be used for various types of printing paper, and the production and installation of the photosensitive drum and the like are facilitated.
[0014]
According to a fourth aspect of the present invention, in the printing machine according to the second or third aspect , the photosensitive drum, the transfer roller, and the backup roller are rotationally driven by the control unit in synchronization with each other. It is characterized by.
[0015]
In the present invention, since the photosensitive drum, the transfer roller, and the backup roller are driven to rotate synchronously, the drawing portion is not displaced and high-quality printing is possible.
[0016]
According to a fifth aspect of the present invention, in the printing press according to any one of the second to fourth aspects, each of the developing rollers provided in the plurality of toner storage chambers is independent of the photoreceptor. The said space | interval with respect to a drum can be adjusted, It is characterized by the above-mentioned.
[0017]
In the present invention, since the intervals between the plurality of developing rollers can be independently adjusted with respect to the photosensitive drum, manufacturing errors and mounting errors of the developing rollers can be absorbed. Since the interval can be maintained, high-quality printing is possible.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a printing press according to the present invention will be described based on the drawings.
As shown in FIG. 1, the printing machine 1 according to the present embodiment forms an image by sequentially superposing colors such as yellow, magenta, cyan, and black on drawing data created based on print image data. On-image printing is performed, and a photosensitive drum 2 on which an image is formed is provided.
[0019]
In the vicinity of the photosensitive drum 2, a charger 3 as a charging unit that imparts electrostatic charge to the photosensitive drum 2 to impart photosensitivity, and light is applied to the charged photosensitive drum 2 for a certain period of time. An exposure unit 4 is provided as exposure means for forming an electrostatic latent image on the body drum 2.
Further, a developing unit 19 for developing the electrostatic latent image formed on the photosensitive drum 2 with liquid toner is provided below the photosensitive drum 2, for example, above the photosensitive drum 2. There are provided a transfer roller 6 for pressure-transferring the printed image on the surface, and a backup roller 7 for backing up from above the transfer roller 6 to prevent escape of pressing due to the deflection of the transfer roller 6 and applying a strong printing pressure to the whole. Furthermore, a control means 20 is provided for controlling the entire printing machine 1 including driving of the photosensitive drum 2 and the transfer roller 6 described above.
[0020]
The photosensitive drum 2 is provided with a first servo motor 8, the transfer roller 6 is provided with a second servo motor 9, and the backup roller 7 is provided with a third servo motor 10, and these servo motors 8, 9, 10 are provided. By driving, the photosensitive drum 2, the transfer roller 6, and the backup roller 7 are configured to be driven synchronously under the control of the control means 20.
[0021]
The photosensitive drum 2 and the transfer roller 6 have the same diameter, and the backup roller 7 and the photosensitive drum 2 have the same diameter.
The transfer roller 6 can be attached to and detached from the photosensitive drum 2 by a transfer roller attaching / detaching actuator 47 (see FIG. 6), and the backup roller 7 is transferred by a backup roller actuator 48 (see FIG. 6). The roller 6 is detachable.
The backup roller 7 and the photosensitive drum 2 may have different diameters.
[0022]
As shown in FIG. 2, the exposure device 4 includes a polygon scanner 91 that rotates at a constant rotation, an fθ lens 92 that collects laser light from the polygon scanner 91, and a laser diode 93 that is incident on the polygon scanner 91. The laser beam that is configured and output from the laser diode 93 is incident on the polygon scanner 91 and reflected, and scans the photosensitive drum 2 through the fθ lens 92.
[0023]
Here, as shown in FIG. 3, a drawing area H, a non-drawing area I, and the like are formed on the photosensitive drum 2.
That is, a drawing area H having a predetermined size is formed at the center of the circumferential length G of the photosensitive drum 2, and non-drawing areas I are formed at both ends thereof. And the other side end is the final drawing line B. On the other hand, a scanning width E in which scanning by the polygon scanner 91 is performed is determined with respect to the width F of the photosensitive drum 2, and in the scanning width E, one end of the scanning start line, that is, the drawing start line A is the drawing origin C. The drawing end point D is the scanning end line, that is, the other end of the final drawing line B. Then, the encoder detection angle of the scanning origin C is stored in the phase synchronization control unit 40.
[0024]
When the laser light output from the laser diode 93 scans the photosensitive drum 2, as shown in FIG. 4, the dummy signal is first transmitted from the process control unit 35 through the exposure control unit 30 to synchronize with the drawing position. A synchronous signal for drawing is output from the exposure device 4 in response to the dummy signal, but the laser beam reflected from the polygon scanner 91 and reflected again by the mirror 95 through the fθ lens 92 is used for synchronous detection. The detection position detected by the photodetector 94 is output as the drawing synchronization signal. Then, after a predetermined time t has elapsed from the synchronization signal detection position, drawing is started by the drawing signal, and drawing data is created.
A control circuit for the laser diode 93 and a control circuit for the polygon scanner 91 are provided in the exposure control unit 30.
[0025]
Returning to FIG. 1, the developing means 19 includes a developing machine main body 5 and a developing roller 15 provided in the developing machine main body 5.
The developing machine body 5 includes a base 5A and a plurality of toner storage chambers 5B, 5C, 5D, and 5E provided on the base 5A.
The toner storage chamber 5B stores the liquid toner of the first color among the four process colors, for example, yellow plate, and the toner storage chamber 5C stores the second color of the four process colors, for example, red plate. Liquid toner is stored, and the toner storage chamber 5D stores the third of four process colors, for example, indigo liquid toner. The toner storage chamber 5E stores the four process colors. A fourth color, for example, a black plate of liquid toner is accommodated.
[0026]
The developing roller 15 includes a first developing roller 15B provided in the toner containing chamber 5B, a second developing roller 15C provided in the toner containing chamber 5C, a third developing roller 15D provided in the toner containing chamber 5D, and a toner containing chamber. The developing roller 15E provided in 5E can supply the liquid toner in the storage chambers 5B, 5C, 5D, and 5E to the photosensitive drum 2 by the developing roller 15B and the like. ing.
[0027]
Each of these developing rollers 15B to 15E is selected corresponding to each color electrostatic latent image formed on the photosensitive drum 2. In this selection, based on a command to the developing machine moving motor 11 output from the process control unit 35 described later, the developing machine moving mechanism 12 is driven by the motor 11 and the developing rollers 15B to 15E are moved to the developing positions. It is realized by positioning. Further, the driving of each of the developing rollers 15B to 15E maintains a predetermined fixed speed ratio with respect to the photosensitive drum 2.
[0028]
Each of the developing rollers 15B to 15E is independently connected to the developing roller driving motor 17 and the developing roller interval adjusting motor 18, and is rotationally driven by the developing roller driving motor 17, and the developing roller interval adjusting motor 18 rotates the photosensitive drum. 2, the interval L can be adjusted as shown in FIG. 5 while maintaining a predetermined fixed speed ratio.
Here, the distance L between the developing rollers 15B to 15E and the photosensitive drum 2 is such that the liquid toner moves by electrophoresis when the developing rollers 15B to 15E are brought close to the photosensitive drum 2, but in the capillary phenomenon, the liquid toner is moved. Is an interval that does not move, and is set to an optimum dimension capable of forming a clear image. The interval L is a dimension obtained based on experience and experiment in advance corresponding to the rotational speed of the photosensitive drum and the developing roller, the characteristics of the liquid toner, and the like, and the dimension is stored as a parameter shown in FIG. Stored in the unit 45.
[0029]
The printing paper W is supplied between the backup roller 7 and the transfer roller 6 from a paper transport actuator 49 (see FIG. 6) constituting the printing paper transport means so that the print image on the transfer roller 6 is pressure-transferred. It has become.
[0030]
FIG. 6 shows the control means 20 of the printing press 1 as described above, and this control means 20 includes a drawing data creation unit 25, an exposure control unit 30, a process control unit 35, and a phase synchronization control unit 40. Has been.
[0031]
The drawing data creation unit 25 edits and prints drawing data to be drawn based on print image data using a small computer system such as a personal computer or a workstation to create a publication. The drawing data created using a DTP (desktop publishing) system is output using, for example, a PS file, a PDF (Portable Document Format) file, a TIFF (Tagged Image File Format) file, or the like.
The drawing data creation unit 25 possesses functions corresponding to the respective file formats, and creates drawing data to be used by the printing press 1 using the functions. Note that the drawing data creation unit 25 also performs processing for four color separation processing, RIP (Raster Image Processor) processing, and the like corresponding to the file format.
[0032]
The created drawing data is transmitted to the exposure control unit 30, and the exposure control unit 30 converts the drawing data into a signal (exposure signal) for driving the exposure unit 4, and the exposure signal is transmitted to the exposure unit 4. The
[0033]
Next, the phase synchronization control unit 40 will be described with reference to FIG.
The phase synchronization control unit 40 includes a DSP (digital signal processor) unit 41, a servo controller unit 42, and an input / output I / F 53 that operate as an integrated control unit.
The servo controller unit 42 includes a first servo controller 43, a second servo controller 44, and a third servo controller 45. Each of the servo controllers 43, 44, 45 includes the first servo motor 8 and the second servo motor. 9 and the third servo motor 10, and exchanges drive command signals and phase signals between the process control unit 35 and the exposure control unit 30 via the input / output I / F 53.
[0034]
The DSP unit 41 simultaneously gives a single position command (rotation angle) signal to each servo controller 43, 44, 45 of the servo controller unit 42.
The position command signals output to the servo controllers 43, 44, 45 are sent to the first servo amplifier 46, the second servo amplifier 47, and the third servo amplifier 48, respectively. A drive signal corresponding to the position command signal is output to the first servo motor 8, the second servo motor 9, and the third servo motor 10, respectively, and the first encoder 50, the second encoder 51, and the third encoder 52 are output. Are input to the servo controllers 43, 44, and 45, respectively.
[0035]
The first, second, and third servo controllers 43, 44, and 45 constitute position loops 55, 56, and 57 having fixed periods (servo system sampling periods), respectively, and are software servos that control each servo system. Has function.
The DSP unit 41 maintains a time interval corresponding to the speed command during low speed operation, and continuously transmits a position command signal to each servo controller 43, 44, 45. At this time, the synchronization of the photosensitive drum 2, the transfer roller 6, and the backup roller 7 is maintained by software synchronization of the DSP unit 41.
Further, at the time of acceleration and deceleration, a position command signal is continuously transmitted while maintaining a rate of change according to an acceleration time and a deceleration time according to a predetermined target angular acceleration, and the photosensitive drum 2 is synchronized with software of the DSP unit 41. The synchronism between the transfer roller 6 and the backup roller 7 is maintained.
[0036]
Here, the DSP unit 41 calculates the position command (rotation angle) to the third servo controller 45 for the backup roller 7 from the position command (rotation angle) to the first servo controller 43 for the photosensitive drum 2. The calculation of the position command (rotation angle) to the third servo controller 45 from the position command (rotation angle) to the second servo controller 44 for the transfer roller 6 is performed as a backup roller diameter set in advance as a parameter. The speed ratio between the backup roller / backup roller servomotor and the speed ratio between the transfer roller / transfer roller servomotor are used.
[0037]
That is,
Db: Backup roller diameter Gb: Backup roller / backup roller servo motor speed ratio Nm: Backup roller servo motor speed Dt: Transfer roller diameter Gt: Transfer roller / transfer roller servo motor speed ratio N: Transfer roller servo motor speed (= Transfer roller servo motor position command: command to give position change per unit time)
V: When the peripheral speed is
The peripheral speed (web speed) around the transfer roller is
V = N · Gt · πDt (1)
Also, since the peripheral speed on the backup roller is the same as the transfer roller peripheral speed,
V = Nm · Gb · πDb (2)
Therefore, from the equations (1) and (2), Nm = N × Gt · Dt / Gb · Db
From this equation, a position command (rotation angle) signal (command to give a position change per unit time) that becomes “Nm” is backed up from a position command (rotation angle) signal given to the second servo controller 44 for the transfer roller 6. It can be seen that it may be given to the third servo controller 45 for the roller 7.
[0038]
The photosensitive drum 2 is driven by the first servo motor 8 as described above, and the rotation angle of the photosensitive drum 2 is recognized by the output from the feedback encoder 50 as shown in FIG. Each process (printing procedure) is executed by recognizing the rotation angle.
[0039]
Next, the printing procedure of this embodiment will be described based on FIG.
First, the drawing origin C is provided on the photosensitive drum 2 (see FIGS. 2 and 3), and the encoder detection angle is stored in the phase synchronization control unit 40.
In step (hereinafter referred to as ST) 1, the interval L between the developing rollers 15B to 15E and the photosensitive drum 2 is set to a predetermined dimension at which an image is formed in an optimum state. In ST2, the drawing origin is set. When C reaches the charging position of the charger 3, the charger 3 is turned on to charge the photosensitive drum 2. Next, when the exposure position of the exposure device 4 is reached, in ST3, the exposure control unit 30 draws one line for drawing the first color, for example, yellow plate, while maintaining the synchronization with the drawing position. The peripheral speed of the photosensitive drum 2 is set in advance so that the polygon scanner 91 moves by one dot in one surface scanning time, and the photosensitive drum 2 is drawn until a predetermined final line is drawn. Drawing is executed while maintaining the two-dimensional synchrony of the circumference and width of the.
[0040]
In ST4, development is performed when the drawing origin C reaches the development position, and the liquid toner of the first color is transferred from the development roller 15B for the first color onto the latent image on the surface of the photosensitive drum 2 to form a print image. . At this time, the interval L between the developing roller 15B and the photosensitive drum 2 is set so that the liquid toner can be transferred in an optimum state as described in ST1.
After the development of the last line of the first color is completed, the developing means 19 is moved for development of the second color in ST5.
[0041]
In parallel with this, when the drawing origin C reaches the drawing position, the exposure control unit 30 starts drawing the second color in ST6. Synchronization with the rotation of the photosensitive drum 2 at this time is performed in the same manner as the first color, and thereafter, similarly, the second color development is performed in ST7, the developing means 19 is moved in ST8, the third color is drawn in ST9, and the third color development is performed in ST10. The developing means 19 is moved in ST11, the fourth color drawing is performed in ST12, and the fourth color development is performed in ST13. After the fourth color development, the developing means 19 is moved to the initial position by the developing machine moving mechanism 12.
[0042]
Until the above ST13, the transfer roller 6 is disengaged from the photosensitive drum 2, and after the development of the fourth color is completed, the transfer roller 6 is attached to the photosensitive drum 2 in ST14. In ST15, the backup roller 7 is attached to the transfer roller 6. In ST16, the image is transferred from the photosensitive drum 2 to the transfer roller 6. In ST17, the image is transferred from the transfer roller 6 to the printing paper W, and printing is completed. .
The charger 3 is turned off after the last line of the fourth color passes the position of the charger 3.
[0043]
As described above, a full-color print image is formed on the photosensitive drum 2 by the image-on-image, but the movement of the developing unit 19 is performed while the section between the drawing final line B and the drawing origin C is at the developing position. The photosensitive drum 2 and the transfer roller 6 are attached, and the transfer roller 6 and the backup roller 7 are also attached while the section between the drawing final line B and the drawing origin C is at the contact position of the photosensitive drum 2 and the transfer roller 6. .
[0044]
That is, after a full-color print image is formed on the surface of the photoconductive drum 2, in ST13, the final drawing line B passes through the contact position between the photoconductive drum 2 and the transfer roller 6 and then the transfer roller 6 is attached, and the drawing origin is set. From C to the final drawing line B, the print image on the photosensitive drum 2 is pressure-transferred onto the transfer roller 6, and in ST14, the position at which the image on the transfer roller 6 reaches the contact position with the backup roller 7 is determined. Detected by the encoder angle of the photosensitive drum 2, the printing paper W is supplied from the paper transport mechanism between the backup roller 7 and the transfer roller 6, and the image on the transfer roller 6 is sequentially drawn from the drawing start line A to the last line in ST17. The pressure up to B is transferred onto the printing paper W.
[0045]
In the embodiment configured as described above, the following effects can be obtained.
(1) Since the distance L between the surfaces of the first to fourth developing rollers 15B to 15E and the surface of the photosensitive drum 2 can be adjusted, the rotation of the photosensitive drum 2 is performed every time different types of printing are performed. The interval L can be determined in accordance with the speed, the rotation speed of the developing rollers 15B to 15E, the characteristics of the liquid toner, and the like. The interval L may be selected in advance from various dimensions obtained based on experience and experiment and stored in the storage unit 45. As a result, the liquid toner can be supplied at an optimal interval at which the image becomes clear. Therefore, the influence on the image can be suppressed and the image quality can be maintained at a high level.
[0046]
(2) The liquid toner corresponding to the printing color can be stored for each color in the toner storage chambers 5B to 5E, and the developing rollers 15B to 15E are provided in the storage chambers 5B to 5E, so that the colors are not mixed. Multi-color printing is possible and can meet the needs of various customers.
[0047]
(3) Since the developing machine main body 5 and the developing roller 15 are moved using the non-drawing area I, this movement does not affect the drawing, and the drawing of the next color can be quickly performed. Further, since the drawing area H and the non-drawing area I are provided, the size of the printing paper can be dealt with by changing the range of the non-drawing area I. Accordingly, the single photosensitive drum 2 and the transfer roller 6 can handle various types of printing paper, and the production and installation of the photosensitive drum and the like are facilitated.
[0048]
(4) The transfer roller 6 is disengaged from the photosensitive drum 2, and the transfer roller 6 is disengaged from the photosensitive drum 2 until the development of the photosensitive drum 2 by the developing means 19 is completed. Since the mutual engagement is disengaged until the printing paper W is disposed between the backup roller 7 and the transfer roller 6 with respect to the transfer roller 6, the development of multicolor printing on the surface of the photosensitive drum 2 is performed by the transfer roller. 6, and the printing paper W can be fed without being interrupted by the backup roller 7. As a result, smooth printing can be performed.
[0049]
(5) Since the photosensitive drum 2, the transfer roller 6 and the backup roller 7 are rotationally driven by the control means 20 in synchronism with the respective phases, the drawing portion is not shifted and high-quality printing is performed. It becomes possible.
(6) The first to fourth developing rollers 15B to 15E respectively provided in the plurality of toner storage chambers 5B to 5E can independently adjust the interval L with respect to the photosensitive drum 2. Therefore, manufacturing errors and mounting errors of the developing rollers 15B to 15E can be absorbed, and the developing rollers 15B to 15E can maintain a uniform interval, thereby enabling high-quality printing. .
[0050]
In addition, this invention is not limited to the said embodiment, The following modifications may be sufficient as long as the objective of this invention can be achieved.
That is, in the embodiment, the printing machine 1 is used for printing, but the printing machine 1 can also be used for test printing, that is, for calibration.
[0051]
In the above-described embodiment, the first to fourth developing rollers 15B to 15E can independently adjust the interval L with respect to the photosensitive drum 2. Thus, the interval L with respect to the photosensitive drum 2 may be adjustable.
[0052]
【The invention's effect】
According to the printing machine of the present invention, since the interval between the surface of the developing roller and the surface of the photosensitive drum can be adjusted, the rotational speed of the photosensitive drum, the rotational speed of the developing roller, and The interval can be determined according to the characteristics of the liquid toner. As a result, since the liquid toner can be supplied at an optimal interval at which the image is clear, the influence on the image can be suppressed and the image quality can be maintained at a high level.
[Brief description of the drawings]
FIG. 1 is an overall view showing an embodiment of a printing machine according to the present invention.
FIG. 2 is a view showing an example of an exposure system in the printing press of the embodiment.
FIG. 3 is a diagram illustrating a drawing area, a non-drawing area, a drawing origin, and the like on the photosensitive drum in the printing machine according to the embodiment.
FIG. 4 is a diagram illustrating an example of synchronization detection timing at the start of drawing in the printing press according to the embodiment.
FIG. 5 is a diagram illustrating a relationship between the photosensitive drum and the developing device of the embodiment.
FIG. 6 is a diagram illustrating a control mechanism in the printing press according to the embodiment.
FIG. 7 is a diagram showing a phase synchronous drive system in the printing press of the embodiment.
FIG. 8 is a flowchart of processing in the printing machine of the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Printing machine 2 Photoconductor drum 3 Charger 4 Exposure device 5 which is exposure means Developer body 5B-5E which constitutes development means Toner storage chamber 6 Transfer roller 7 Backup roller 15 Development rollers 15B-15E First to fourth development Roller 19 Developing means 20 Control means 25 Drawing data creation section 30 Exposure control section 35 Process control section 40 Phase synchronization control section 45 Storage section

Claims (5)

A photosensitive drum on which an image is formed; and
Charging means for charging the surface of the photosensitive drum;
Exposure means for exposing the surface of the photosensitive drum after charging by the charging means to create an electrostatic latent image; and
Developing means for developing the electrostatic latent image on the surface of the photosensitive drum by supplying liquid toner to the surface of the photosensitive drum by electrophoresis after exposure by the exposing means;
A transfer roller for receiving an image developed by the developing means;
A backup roller for transferring the image on the transfer roller to printing paper;
Each of these means and a control means for controlling each roller,
The developing means includes a developing machine main body that stores the liquid toner, and a developing roller that is provided in the developing machine main body and supplies the liquid toner to the photosensitive drum and develops the surface. The distance from the surface of the photosensitive drum can be adjusted,
The transfer roller is formed to be engageable with and disengaged from the photosensitive drum, and the backup roller is formed to be able to engage with and disengage from the transfer roller. Until the development of the photosensitive drum is completed by the means, and the backup roller engages with the transfer roller until the printing paper is disposed between the backup roller and the transfer roller. A printing machine characterized in that the joint is separated.   2. The printing machine according to claim 1, wherein the developing device main body includes a plurality of toner storage chambers that store liquid toners corresponding to a plurality of printing colors, and the developing rollers are provided in the plurality of toner storage chambers, respectively. A printing machine characterized by the above.   The printing press according to claim 2, wherein the photosensitive drum and the transfer roller are formed to have the same diameter, and each has a drawing area where drawing is performed and a non-drawing area where drawing is not performed, The printer according to claim 1, wherein movement of the developing machine main body and the developing roller corresponding to a predetermined printing color among a plurality of printing colors is performed within a non-drawing area of the photosensitive drum. 4. The printing machine according to claim 2 , wherein the photosensitive drum, the transfer roller, and the backup roller are rotationally driven by the control unit in synchronization with each other.   5. The printing press according to claim 2, wherein each of the developing rollers provided in the plurality of toner storage chambers independently adjusts the interval with respect to the photosensitive drum. 6. A printing machine, characterized in that it is possible.

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