JPS5920034B2 - electrophotographic method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic method using a laser beam, and particularly to an electrophotographic method using a wide transfer material such as a fabric.

Conventionally, roller printing, screen printing, and transfer printing have been used as methods for printing images on fabrics.

However, all of these methods have advantages and disadvantages as will be described later, and improvements in the technology have been desired. In recent years, consumer needs have diversified, the production volume of fabrics printed with the same image has decreased, and the trend toward producing a wide variety of products in small quantities has become stronger.

For example, the printing method using electrophotography was developed in
35, is known from Japanese Patent Publication No. 47-12237.

However, these methods merely demonstrated the applicability of electrophotography as a means of textile printing, and it is difficult to call them textile printing methods that meet the current situation. As shown in the block diagram of FIG. 1, the textile printing method to which the present invention is applied is based on the following configurations (1) to (5).

(1) A computer that outputs graphic information to be printed;
(2) an interface means for converting computer terms into control signals for an electrophotographic printer; (3) an electrostatic latent image is formed on the electrophotographic photoreceptor by signals from the interface means, and the developed image is developed; An electrophotographic printer section that transfers images onto fabrics and performs other processes necessary for electrophotography if necessary.

(4) The electrophotographic printer section includes eight laser light sources, CR
Exposure means such as T optical system, exposure control means for controlling the exposure means (B) Electrophotographic photoreceptor (q Image forming means for forming an electrostatic latent image on the electrophotographic photoreceptor and developing it with toner) , image forming control means for controlling the image forming means (image transfer means for transferring the toner image onto fabrics)
It is composed of other means necessary for electrophotography.

(5) Toner that is no longer needed after the toner image transferred onto the fabric is fixed on the fabric, or the dye in the toner is dyed onto the fabric by steaming, heating, chemical treatment, etc. Image dyeing means to remove components and complete the print. The textile printing apparatus with the above configuration has the following features.

(2) Conventionally, it took a long time to make printing rollers, screens, etc., but this time is greatly shortened. Also, plate making was extremely expensive. However, according to the present invention, plates can be made extremely easily and in a short time, making print production more flexible and eliminating the economic burden caused by hit-or-miss print patterns in the planning aspect of print production. The amount of printed fabric can be reduced to a large extent, and any printed fabric that meets the demand can be supplied at will. (B) Patterns can be replaced by replacing the computer's input means (for example, perforated tape, magnetic tape, ferromagnetic disk, etc.), and colors can be replaced by replacing the developing device (developing brush unit, developing tank unit, etc.). Since it can be easily replaced, the operating rate of the apparatus is improved, and the complicated and dirty work such as washing the plate, which was conventionally performed, can be omitted.

Due to the above two reasons, it is possible to produce a wide variety of printed patterns in small quantities, which are becoming increasingly fashion-oriented, and to reduce the economic burden on producers, it is possible to significantly reduce the cost of printed fabrics. . In particular, the electrophotographic photosensitive plate used in this method has a conductive substrate with Se,
．． Se-Te. Those coated with Se alloy such as Se-Te-As by vapor deposition or binder resin, and CusC
It is advantageous to use a photosensitive plate with a seamless three-layer structure in which a photoconductive layer such as CdS activated by lactic acid is coated with a binder resin and an insulating layer is used because it is physically and chemically stable. It is.

However, it goes without saying that the present invention can also be applied to a two-layer photosensitive plate consisting of a photoconductive layer and a conductive substrate. Furthermore, as an image forming method, when an electrostatic latent image is formed by applying the Carlson method to a photosensitive plate having a two-layer structure, a residual potential tends to remain in the 1-light area, and it is difficult to obtain a potential contrast.

When the electrophotographic method described in Japanese Patent Publication No. 42-23910 of the present applicant is applied, the light part has a polarity opposite to that of the dark part, and the contrast is high.

When printing on fabrics, so-called fog contaminates the white background and greatly reduces the product value. Therefore, the potential contrast is high (bias voltage can be applied to the developing brush to prevent fogging) and 1ig
It has been found that the two characteristics of the ht portion having opposite polarity (less fogging even without a developing bias) are extremely advantageous in putting the electrophotographic printing method into practical use.

Next, the present invention will be described in detail based on examples and with reference to the drawings.

FIG. 2 is a diagram schematically showing the basic configuration of this embodiment.

A laser beam oscillated by a laser oscillator 1 is guided to an input aperture of a modulator 3 via a reflecting mirror 2.

It is inserted to bend the optical path in order to reduce the space of the reflecting mirror 2K device, and can be removed if it is not needed. For the modulator 3, an acousto-optic modulation element using a known acousto-optic effect or an electro-optic element using an electro-optic effect is used.

In the modulator 3, the laser beam is modulated in intensity according to the input signal to the modulator 3.

In addition, when the laser oscillator is a semiconductor laser, a gas laser, etc. that can perform current modulation, or an internally modulated laser that incorporates a modulation element in the oscillation optical path, The modulator 3 is omitted and the beam is guided directly to the beam expander 4. The beam diameter of the laser beam from the modulator 3 is expanded by a beam expander while it remains a parallel beam.

Furthermore, the laser beam with enlarged beam diameter cuts the mirror surface by 1
The light is incident on the polyhedral rotating mirror 5, which has one or more polyhedral rotating mirrors. The polyhedral rotating mirror 5 is mounted on a shaft supported by a high-precision bearing (for example, an air bearing), and is driven by a motor 6 that rotates at a constant speed (for example, a hysteresis synchronous motor, a DC servo motor). , the horizontally swept laser beam 12 is imaged as a spot on the photosensitive drum 8 by an imaging lens 7 having f-θ characteristics. In a general imaging lens, when the incident angle of a light ray is θ, there is a relationship as follows regarding the imaging position r on the image plane, where f is the focal length of the imaging lens, and as in this example, it is constant. Laser beam 12 reflected by rotating polyhedral mirror 5
The angle of the imaging lens changes linearly over time. Therefore, the moving speed of the imaged spot position on the photosensitive drum 8, which is the image surface, changes non-linearly and is not constant. That is, the moving speed increases at the point where the angle of incidence increases. Therefore, at regular time intervals, the laser beam is
When a row of spots is drawn on the photosensitive drum 8, the distance between them is wider at both ends than at the center. In order to avoid this phenomenon, the imaging lens 7 is designed to have the following characteristics.

Such an imaging lens 7 is called an f-θ lens.

Furthermore, when collimated light is imaged into a spot by an imaging lens, the minimum diameter Dmin of the spot is given by: f; focal length λ of the imaging lens; wavelength A of the light used; Therefore, if f1λ is constant, a smaller spot diameter Dmin can be obtained by increasing A.

The beam expander 4 mentioned above is used to provide this effect. Therefore, if the required Dmin can be obtained by the beam diameter of the laser oscillator, the beam expander 4 is omitted. The beam detector 18 consists of a small entrance slit and a photoelectric conversion element with a fast response time (for example, a PIN diode).

The beam detector 18 detects the position of the swept laser beam 12, and uses this detection signal to determine the start timing of the input signal to the modulator 3 for providing desired optical information on the photosensitive drum. do. As a result, errors in the division accuracy of each reflecting surface of the polyhedral rotating mirror 5 and synchronization deviations in horizontal signals due to uneven rotation can be greatly reduced, and high-quality images can be obtained, and the polyhedral rotating mirror 5 And the tolerance range of accuracy required for the drive motor 6 becomes larger,
It can be manufactured at a lower cost. However, the fabrics that are generally printed are about 1m50C7rL.

When the width of the drum surface to be swept is 1m50cm4 degrees, it is difficult to install just one beam detector at the end.
It is difficult to suppress the synchronization deviation due to the other end to within an allowable value. In such a case, it is desirable to adopt the multi-beam detection method described later. As described above, the deflected and modulated laser beam 12 is irradiated onto the photosensitive drum 8, visualized by an electrophotographic processing process, and then transferred to a fabric.
It is dyed and a textile print is created.

Dyeing here refers to transferring a toner colored with pigment dye etc. and dyeing it onto fabrics by steaming etc., transferring invisible toner onto fabrics and dyeing it by coloring process, dyeing on fabrics etc. This refers to partially erasing the color of fabrics using transferred toner, resist dyeing treatment, etc.

Next, the printing section 20 will be explained with reference to FIG. 3.

As an example of the electrophotographic process applied to this embodiment, a photosensitive plate whose basic constituents are a conductive support, a photoconductive layer, and an insulating layer, as described in Japanese Patent Publication No. 42-23910 of the present applicant. The surface of the insulating layer of 8 is charged with a first corona charger 9
The charged insulating layer is uniformly charged positively or negatively in advance, and charges with the opposite polarity to the charged polarity are captured at the interface between the photoconductive layer and the insulating layer or inside the photoconductive layer, and then the surface of the charged insulating layer is Simultaneously with the irradiation of the laser beam 12, an AC corona discharge is applied by an AC corona discharger 10 to form a pattern on the surface of the insulating layer due to a difference in surface potential that occurs according to the light and dark pattern of the laser beam 12, The entire surface of the insulating layer is uniformly exposed to light to form a high-contrast electrostatic image on the surface of the insulating layer, and the electrostatic image is further developed by a developing device 13 using a developer mainly composed of charged colored particles.
After developing and visualizing the visible image, the visible image is transferred to a transfer material 11 such as cloth using an internal or external electric field, and then the transferred image is transferred using a fixing means 15 such as an infrared lamp or a hot plate. An electrophotographic print image is obtained by fixing, and after transfer, the surface of the insulating layer is cleaned by a cleaning device 16 to remove remaining charged particles, and the photosensitive plate 8 is used repeatedly.

The developer used in the development process is: (1) dyes, pigments, etc. are dispersed in a resin, and the resin powder is pulverized to about 5 to 30μ and mixed with iron powder, glass beads, etc. to charge it to a certain polarity. Dry developer (2) A wet developer in which dyes, pigments, resins, etc. are dispersed in a nonpolar solvent (e.g., isoparaffin) and the charge is controlled so that the dispersed particles are charged to a constant polarity. Often.

When a pigment is used as the coloring agent in the developer, the pigment is fixed and dyed on the fabric with a resin in the same way as in general pigment printing methods, and dyed with acid dyes, basic dyes, disperse dyes, vat dyes, When a reactive dye or the like is used, the dye is applied to the fabric by steaming, chemical treatment, or the like.

If unnecessary components in the developer remain on the fabric after dyeing, they are removed by water washing, noping, solvent treatment, etc.

Refer to Figure 4 for further details on the phenomenon that occurs on the photoreceptor when the surface of the insulating layer, which has been uniformly charged in advance, is attenuated by alternating current corona discharge to attenuate the charge on the surface of the insulating layer and simultaneously irradiated with laser light. I will explain it in detail.

FIG. 4 shows the state of change in surface potential on the surface of the insulating layer of the photoreceptor.

FIG. 4a shows a case where the frequency of the alternating current of the alternating current corona discharge is relatively low.

At this time, the potential of the surface of the insulating layer during AC neutralization can take an intermediate value between the curve shown by the solid line and the curve shown by the dotted line due to the difference in the potential sum of the AC voltage. However, the laser beam is irradiated for a very short time, for example, 50 nanoseconds in this embodiment, for a specific location on the photoreceptor. For this reason, due to the difference in the potential of the surface of the insulating layer when the laser beam is irradiated, the potential of the electrostatic image obtained after the entire surface is exposed varies, even though the amount of laser beam irradiation is constant.
It won't be constant. Therefore, unevenness synchronized with the frequency of the alternating current occurs in the developed image. This phenomenon does not occur because exposure is performed over the entire AC static neutralization area during application to copying machines and the like, so the influence of the phase is averaged out and does not appear. In order to eliminate this uneven phenomenon, when the frequency of AC static elimination is increased (Fig. 4b), the amplitude of the fluctuation in the surface potential of the insulating layer that is synchronized with the AC frequency does not change the overall static elimination time. decreases.

Therefore, the difference in potential on the surface of the insulating layer during laser beam irradiation is reduced, and the unevenness in the developed image becomes practically negligible. This is explained by the equivalent circuit shown in FIG. In Figure 5, E is the voltage applied to the discharge electrode of the AC corona discharger, Rc is the resistance when corona current flows between the discharge electrode and the photoreceptor, and Cp is the photoreceptor considered as a load with only capacitance. It shows the capacitance of the photoreceptor at the time. At this time, the potential on the surface of the insulating layer immediately before AC static elimination due to temporary charging is VO, and the voltage applied to the AC corona discharge electrode is E -
When EOcOs (Wt+ 0 ), the potential Vp of the surface of the insulating layer during AC static elimination is expressed as follows.

From equation (4), the static elimination time is given by the second term on the right side, and its time constant T is CpRc.

Further, the amplitude of the fluctuation due to the frequency of AC corona discharge is given by 7 tetetei 〒te==゛ from the first term.

Also, from Figure 6, the AC static elimination time Td is v; drum peripheral speed 1: Given by the width of the static elimination area.

Furthermore, the amount corresponding to Cp in the equivalent circuit of FIG. 5 is proportional to the surface area of the photoreceptor that passes through the static elimination area per unit time.

A: Proportional constant Here, assuming that static electricity is sufficiently removed under the conditions of C, = CPI, Rc = Rcl, and V = V1, the time constant of static electricity removal in equation (4) is then AC discharge Frequency W. It is assumed that the amplitude WO of the fluctuation caused by is large enough to cause density unevenness in the developed image.

By setting w=W, (W,>W.), we get W
1 is assumed to be sufficiently small so as not to cause the density unevenness.

In this way, by changing the frequency of AC corona discharge, the density unevenness can be removed without changing the static elimination time.

Next, assuming that the circumferential speed of the drum is v - Av, = V, the static elimination time must therefore be equal to the static elimination time constant in order for the static electricity to be sufficiently eliminated within the static elimination time Td.

In practice, changing Rc is achieved by changing the distance between the discharge electrode wire and the photoreceptor.

At this time, the amplitude of the fluctuation due to the frequency of the AC corona discharge is as follows.If we find the condition of W for the prefecture to be equal to 05), we can see that in order to prevent the unevenness of the visible image from occurring, It is necessary to apply an AC corona frequency greater than the value, and the value is proportional to the circumferential speed of the drum.

In this example, the circumferential speed v of the drum is 30 CTrL/
Sec, static elimination area width 3cm x 1m50CT! L, the capacitance C of the photosensitive plate is 5PF/Cd, and the current for AC static elimination is 4
00ftArms, voltage 7KV, frequency f 1KHz,
It was carried out at an electrostatic contrast of about 500V. The development was carried out using liquid development and reversal development. From these experiments, it was possible to remove the unevenness of the forehead image under conditions where the frequency f of AC static elimination was satisfied.

That is, it means that the pitch according to the local wave number of AC corona discharge on the photosensitive drum is 0.3 ml. Therefore, the effect of the above formula A6) is obtained under more general conditions. P is a constant determined by the capacitance of the photoreceptor, the width of the static elimination area, the development conditions, etc., and in the above example, it is 0.0.
It was 3.

As still another example, the present applicant's Japanese Patent Publication No. 42-19
An electrophotographic electrostatic image forming process such as that described in Japanese Patent No. 748 is applied.

That is, using a photosensitive plate whose basic constituents are a conductive support, a photoconductive layer, and a late edge layer, the surface of the insulating layer is uniformly positively or negatively charged in advance by a corona discharge, and becomes photoconductive. A charge having a polarity opposite to the charged polarity is captured on the surface of the insulating layer and the photoconductive layer, and an alternating current corona discharge is applied to the charged surface to attenuate the charge on the surface of the insulating layer, and then, The process of irradiating the laser beam as an information signal, forming an electrostatic image on the surface of the insulating layer according to the brightness of the laser beam, and then developing the electrostatic image is the same as in the first embodiment. It is. The photoreceptor and laser oscillator used in the first and second embodiments were as follows.

Combination A (a) Laser oscillator: He-Ne gas laser, wavelength: 632.8 mμ (b) Photoreceptor: Cadmium sulfide 907 activated by copper for 10y
of vinyl chloride, a small amount of thinner, and the resulting photosensitive material was placed on an aluminum foil approximately 100μ thick.
Apply by spraying to a thickness of 0μ.

Next, a Mylar film with a thickness of about 25 mm was closely laminated on the surface of this photoconductive coating using an adhesive to obtain a photosensitive plate, and the photosensitive member was further wound around a drum made of aluminum. . In the case of this photoreceptor, the charge polarity of the first charge is positive. Combination B (a) Laser oscillator He-Cd laser wavelength 441.6 mμ (b) A Te layer with a thickness of about 1μ is vacuum deposited on the photoreceptor aluminum base, and a layer of Se containing 5% Tel is further applied with a thickness of about 90μ. In the case of this photoreceptor, the first charging polarity is negative.

Furthermore, various laser light sources currently announced or to be announced in the future may also be applied to the first and second latent image forming processes.

It is important to devise a combination of photoreceptors whose spectral sensitivity characteristics match the wavelength of each laser. Laser: Ar gas laser Kr〃 Ar+Kr〃 (visible) semiconductor laser Dye laser Double wavelength conversion using nonlinear crystal of infrared laser light Ikoz21
/′． +fl etc. can be used.

Next, the operation from receiving figures and information from a computer to producing a desired print using the apparatus shown in this embodiment will be explained with reference to FIG.

Information from the computer can be transmitted directly or via magnetic tape.
The data is input to the interface circuit 22 of this device in a specified format via a storage medium such as a magnetic disk. Various instructions from the computer are decoded and executed by instruction execution circuit 24. Data is stored in the data memory 23 in fixed amounts. In the case of graphic information, the data format may be pixel-based data constituting the graphic, or data of lines constituting the graphic (so-called vector data). These modes are specified in advance of the data, and the instruction execution circuit 24 controls the data memory 23 and line data generator 26 to process the data according to the specified mode. The line data generator 26 generates final data for one scan line. Even when the data is graphic information, the data is converted into scan line data to create data for sequentially modulating the laser beam for one line scan.

Data for one scan line is input alternately to line buffer 1 (27) and line buffer 2 (28), which are composed of shift registers and the like, each having a number of bits equal to the surface prime number for one scan line, under the control of a buffer switch control circuit. be done.

Furthermore, the data of line buffer 1 (27) and line buffer 2 (28) is transmitted for one scan line using the beam detection signal from the beam detector 32 as a trigger signal.
Bit by bit is read out sequentially and applied to the modulator control circuit. While one reflective surface scans the photosensitive drum along a line perpendicular to the rotation direction, data for one scan line stored in the line buffer is applied to the modulator, and the bright and dark pattern of one scan line is created. applied to the photosensitive drum 8.

Data is read out alternately from line buffers 1 and 2 (27) and (28) under the control of the buffer switch control circuit. These temporal relationships are shown in FIG. That is, when reading from one line buffer, writing is performed to the other line buffer. This method allows all data to be applied to the modulator when the polyhedral rotating mirror sweeps over the photosensitive drum and the distance between one reflecting surface and the next reflecting surface is very short. While scanning one scan line, the photosensitive drum continues to rotate at a constant speed and moves by an appropriate scan line interval.

Next, a method for enlarging and outputting a figure will be described in detail.
Instead of reading data by alternately switching line buffers 1 and 2 for each scan as described above, when enlarging, data is read out by repeating scanning for each line buffer according to the enlargement ratio.

As a result, at a constant scanning speed and constant drum rotation, the output figure can be enlarged by an integral number of times in the direction perpendicular to the scanning direction. Next, from among the data for one scan in each line buffer, only the target image signal is read out at a bit rate corresponding to an arbitrary enlargement ratio (the vertical and horizontal enlargement ratios may be the same or different). With this, one. [At a constant scanning speed, any part of the figure or data in the line buffer can be arbitrarily enlarged in the scanning direction. As described above, using the same data, figures, etc. can be independently enlarged or transformed in both vertical and horizontal directions and output.

FIG. 10 shows an example of an original output figure and an enlarged deformed output figure.

FIG. 9 shows the time relationship of alternate reading and writing of line buffers 1 and 2 during enlargement and deformation.

Further, upon receiving a start command from the instruction execution circuit 24, the printer control circuit 33 starts printer operation and returns a printer ready signal to the instruction execution circuit 24. When a signal is applied to the modulator 3 and the first data is written to the photosensitive drum, the timing is set so that the written data is transferred to a certain position on the fabric at the transfer position. Fabrics 11 are sent out by the supply mechanism. Thus, the graphical information from the computer 21 is output as a clear print on the fabric. Note that if the rotating photosensitive drum is scanned with a laser beam having an image signal in a direction parallel to the axial direction of the photosensitive drum, the scanning line on the photosensitive drum will be somewhat inclined. To correct this, it is better to tilt the scanning line in advance. (See FIGS. 11A and 11b) In this case, if only the polyhedral rotating mirror is tilted, the scanning line will curve as shown in FIG. 9c. In the present invention, the first
2. As shown in Figure 2, the entire optical system is placed on a bench, and the bench is installed obliquely with respect to the photosensitive drum in a direction that corrects the inclination of the scanning line.

This makes it possible to correctly record images on fabrics as shown in FIG. 11b. Next, an embodiment of the beam multiple detection method will be described using FIGS. 13 and 14. In the figure, before entering the optical modulator 3, a laser beam 12 is split into two beams by a half mirror 101, only one of which is modulated by an external signal by the modulator 3, and the beam passes through a beam expander 4 as necessary. The diameter is expanded.

The optical path of one beam is bent by a fixed mirror 102.
The two beams are reflected by the same surface of the rotating mirror 5 and scanned as a detection beam 103 and an exposure beam 12, respectively. The detection beam 103 does not necessarily have to be a beam emitted from the same laser oscillator 1, but may be a beam emitted from another oscillator. The detection beam 103 is further bent by a fixed mirror 104 in the receiving direction of the plurality of beam detectors u.

Conventionally, in order to reduce the synchronization deviation of horizontal signals due to errors in the division accuracy of each reflective surface of the multifaceted rotating mirror 5 and uneven rotation, the beam position is detected and the start timing of the input signal to the modulator 3 is given. It is common knowledge that this method is used.

However, simply determining the start timing of one scan will inevitably increase the jitter as the scan progresses toward the end.

In particular, if the scanning distance, that is, the recording width is very long, the jitter at the end of the scan cannot be ignored.For example, as in this embodiment, the recording width is 1m50CTn1 per scan
If it is 0 dot, there will be a deviation of 3.5 dots (0.75 dragons) at the end in the case of uneven rotation and surface accuracy of 1/2000. The purpose of this embodiment is to eliminate the imbalance in image quality between the start and end of scanning as described above.

The beam position detection beam 103 is turned into a beam position signal by a plurality of arrayed beam position detectors 18, and the timing of the input signal to the modulator 3 is corrected at each detection position, resulting in a high-quality image. . Next, the signal processing in this embodiment will be specifically explained.

In FIG. 15, the line data generator 26 generates data for one scan. Line buffer 1 and line buffer 2 each consist of a shift register or the like having a number of bits equal to the number of pixels for one scan, and are each divided into blocks equal to the number of beam position detectors 18. In the illustrated example, there are four beam position detectors 18, buffer 1 (27) and buffer 2 (28).
Each block (called an area) consists of 1875 bits. Line buffer 1 and line buffer 2 are line
The position detection signal 1, which is alternately read out from the data generator 26 and outputted to the modulator, the relationship of which is shown in FIG. 16, plays the main role in each scan.

Next, the details of writing, that is, modulation signal output when using the four beam position detectors of this embodiment, will be described using the example of the line buffer 1 in FIG. 17.

First, flip-flop 1 (F/F1) turns ON with the pulse of beam position detector 1 (D1), and at the same time gates the clock from the master clock oscillator and starts sending it to countdown clock A. Start counting clocks. The purpose of this count down clock counter is to reduce the synchronization difference between the clock and the gate. The counted down write clock is sent to area 1 of the line buffer, and the data in area 1 is output. If a signal is received from the second beam position detector 2 before all pixels (1875 bits) in area 1 are clocked, the countdown clock counter B starts counting the master clock by synchronizing that signal. The flip-flop (F/F1) has been reset, the count-down clock counter A no longer outputs a clock, no more data is output from area 1, and the modulated signal becomes the data of area 2. Next, if all the pixels in area 1 have been clocked and no signal is still received from beam position detector 2, area clock counter A and flip-flop A will stop the master clock from counting any more, and From then on, the last pixel is left out, waiting for the data in area 2 to come out.

Eventually, when a signal is input from the beam position detector 2, data of area 2 is output. The same applies to area 3 thereafter. At the end of area 4 is area clock counter B.
The total number of dots is counted and data output ends.
The same operation can be performed for the line buffer 2 by simply switching the line buffer write signal.

By implementing the above steps, the jitter at the seams between areas will be reduced to zero.
．． Very high quality printing with only 9 dots (0.18u) has become possible.

It has been confirmed that this method is particularly effective for designing striped patterns perpendicular to the scanning direction. So far, one-color printing has been described.

The case of multicolor printing is described below. FIG. 18 shows the printing section for two-color printing.

D...Drum (CdS three-layer seamless structure) 1
11...Primary, +112...AC static eliminator (- can also be used) 113...Laser for image exposure He-Nell4...Full irradiation lamp 115
...Developer 116...Post charger (polarity can be either positive or negative, but preferably the same polarity as the toner) 117...
...Transfer roller, conductive ground or transfer bias application (opposite polarity to post) 118...Cleaning unit 120...Set charger (same polarity as post, first color toner is on drum side) 121... Earth electrode 122... Fixing roller A roller heated by an electric or steam heater, respectively.

After fixing, the cloth undergoes processes such as steaming, soaping, and solvent dyeing to complete the print.

In FIG. 18, the transfer process uses a transfer roller 117. Fabrics that have a width of more than 1 m and that have been subjected to washing and removal treatment before transfer have many wrinkles, and it is not possible to obtain a sufficient transferred image by simple corona transfer.

For this reason, in the printing fabric manufacturing process, the most suitable method is roller transfer, in which the fabric is transferred while being pressed against the photosensitive drum using a roller.

The lower the rubber hardness of this transfer roller, the better the transfer rate, giving a good image, and the less damaging the photosensitive drum, but if the rubber hardness is too low, it will be difficult to achieve processing accuracy. The transfer roller used in the present invention preferably has a hardness of 15 to 60 degrees in a JIS spring type hardness tester.
The roller may have a multilayer structure made of different materials, but in that case, it is sufficient to apply a hardness meter to the surface of the roller and find that the value falls between the above values. The transfer roller must be conductive, but rollers made of conductive rubber mixed with carbon black, etc., or rollers made of ordinary rubber or foamed elastic material with a conductive film layer coated or wrapped around them can be used. be exposed. Is the optimum resistance value for the transfer roller a surface specific resistance of 108Ω? Below, preferably 105Ω? The following are preferred. To obtain multicolor prints of three or more colors, just add as many units as necessary within the dotted lines. The role of the post charger 116 in FIG. 18 is to charge the toner forming the image to further improve the transfer rate, and at the same time to charge the non-image area. Although the charging polarity of the post charger may be either positive or negative, the transferred toner image, which is better to have the same polarity as the toner in liquid development, is charged by the set charger 120 to the same polarity as the post charger 116. As a result, the toner image on the fabric, the drum surface of the second color, and the toner image have the same polarity, so that a high-quality print can be obtained without the toner image on the fabric being retransferred onto the drum. In addition, when creating multicolor prints, it is necessary that the polarities of the toner on the fabric, the toner on the drum, and the drum surface be the same during transfer.
, 120 may have the same charging polarity.

Next, an example in which two-color prints were produced using the apparatus shown in FIG. 18 will be described in detail.

CdS three-layer photosensitive plate drum He shown in combination A
Bright area - 100V dark area +
A 400V latent image was created and developed using the developer shown below. Green toner polyester resin 1007 Low molecular weight polyethylene 20y Phthalocyanine Green 77 (Highly chlorinated copper phthalocyanine) The above mixture was kneaded and mixed in a roll mill at 130°C, cooled, and crushed in a hammer mill to obtain a green toner having a particle size of 10 to 20μ. Obtained.

Yellow toner Instead of the green pigment used in the green toner, Benzidine Yellow 1C. I. A yellow toner was obtained by the same treatment using PigmentYellOwl2.

The electrostatic latent image was developed by mixing the toner 137 with 100f of iron powder EFV25O-400 (250-400 mesh manufactured by Nippon Steel Powder), and then transferred onto a cotton cloth.

The drum surface potential after post-charging during transfer is 800V to 10
00V is desirable. If it exceeds 1000V, the transferred image is likely to be distorted.

At this time, the transfer roller was grounded. After the two-color toner image was transferred, the fabric was heated in a chamber at 150° C. for 30 seconds. Through this treatment, the toner image was firmly fixed on the cotton cloth, resulting in a high-quality two-color print.

In the same manner, development was performed using the following toner combination and post-processing was performed to obtain good prints.

Maleic anhydride-polyvinylethe 100yl copolymer (manufactured by GAF, trade name: Gantoretsu) Sumikalon Violet RLlO7 (manufactured by Sumitomo Chemical, sublimable dye) The above components were dissolved in ethanol:water (2/1) 11, and the solution was prepared. 100ml of IsOparH (isoparaffinic solvent, manufactured by Etsuso) 11? ．． Dispersed in lecithin 0.1
7 was added to negatively charge the dispersed particles.

The electrostatic latent image was developed with this developer, and the developer was transferred onto a polyester cloth. The transferred polyester cloth is heated at 120℃,
After drying for 30 seconds, it is heated to 200℃, and then soaped,
It was washed with water to give a good purple print. A block diagram of the control operation in the case of two-color printing of A and B colors is shown in FIG.

The format of the data stored in the data memory 23 is, for example, pixel unit data or so-called vector data, and in addition to specifying these data modes, it also has a color mode.

The line data generators 26 and 26' are of color A, respectively.
Generate final data for one scan of B color.

The timing control circuit 35 is a circuit that controls the exposure timing of each color to prevent color shift. The scanner 1 drive control circuit 34 controls the rotation of the two scanners.

A laser power source 30 and a laser oscillator 1 may be prepared for each color, or the beam may be divided and used.

Some of the timing control methods mentioned above will be explained.

Marks are simultaneously recorded on the edge of the fabric to be printed in the first color at the time of printing the first color.

The marks of the first color are printed at certain reference intervals, and the first color marks are detected and the scanning line number of the second color is corrected to match the first color. The mark may be a code or a point.

The mark detector is made up of a light emitting element and a light receiving element (for example, a light emitting diode and a photodiode). 2. When the fabric is fed by a conveyor belt or the like, the conveyor belt has marks at its ends and is controlled in the same way as in 1.

3. The same control as 1 may be performed by obtaining a signal corresponding to a mark by counting the number of teeth of the fabric conveyance roller or detecting the reference tooth position.

According to the present invention, when a wide electrophotographic photoreceptor is used to form an image on a wide transfer material, even if the laser beam is scanned over a long period, image shift at the end of the scan can be minimized. This provides the effect of being able to obtain high-quality images while keeping the size small.

Although the present invention has been described above in detail with reference to embodiments, it is not limited to the embodiments and includes various modifications within the scope of the claims.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the configuration of one embodiment of the present invention, FIG. 2 is an explanatory diagram of the configuration of one embodiment of the present invention, and FIG.
4 is a diagram showing changes in the surface potential of the insulating layer of the photoconductor, and FIGS. 5 and 6 are equivalent circuits and enlarged explanatory diagrams when performing AC static elimination on the photoconductor. Figure 7 is a process diagram for producing a hard copy from the same figure/information, Figure 8 is a signal waveform diagram in each part of Figure 7, and Figure 9 is an enlarged and modified output character for Figure 8. FIG. 10 is an explanatory diagram of an example of enlarging the output figure and text. FIGS. 11 and 12 are explanatory diagrams of a method for correcting the slope of the scanning line on the photosensitive drum and its apparatus. Figures 13-14
The figures are an explanatory diagram of the configuration of another embodiment and a cross-sectional view of the same stamping part, FIG. The figure is a block diagram for detecting the four beam positions.
19 is a diagram illustrating the configuration of a printing section for two-color printing, and FIG. 19 is a control block diagram of the embodiment shown in FIG. 18.

Claims (1)

[Claims] 1. In an electrophotographic method in which an electrophotographic photoreceptor is scanned with a laser beam modulated by an image information signal to form an electrostatic latent image, and an image corresponding to the electrostatic latent image is transferred to a wide transfer material, An electrophotographic method characterized in that the laser beam is sequentially modulated based on a signal from each element using beam position detection elements.