JPH074945B2 - Electrostatic recording method and device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic recording method and an apparatus therefor used in a printer, a facsimile, etc., and in particular, it generates ions according to an image signal to electrostatically The present invention relates to an electrostatic recording method and apparatus for recording an image.

[Conventional technology]

Conventionally, as this type of electrostatic recording device, there is the following one. That is, as shown in FIG. 16, the electrostatic recording head 101 is arranged so as to face the surface of the dielectric drum 100, and a desired electrostatic latent image is formed on the surface of the dielectric drum 100 by this electrostatic recording head 101. Form.

As shown in FIGS. 17 and 18, the electrostatic recording head 101 includes a plurality of drive electrodes 103, 103 ... On the surface of an insulating substrate 102.
Are provided in parallel with each other, and a plurality of control electrodes 10 are provided on the back surface thereof so as to intersect these drive electrodes 103, 103 ...
4 are provided, and the electrodes 103, 103 ... And 104, 104 ... Form a matrix. Then, the control electrode 10
Openings 105, 105 ... Are formed as discharge generating regions at positions intersecting the drive electrodes 103, 103. Openings 105, 105 ... Formed in these control electrodes 104, 104 ...
Are provided at the positions where the drive electrodes 103, 103 ... And the control electrodes 104, 104 ... Which form the matrix intersect, so that these openings 105, 105 ... Also, as shown in FIG.
It constitutes a matrix.

Further, as shown in FIGS. 19 and 20, a screen electrode 107 is provided on the lower surface of the control electrodes 104, 104 ... Through an insulating layer 106, and these insulating layer 106 and the screen electrode 107 are provided. As shown in FIG. 20, the control electrode 104,
The openings 10 are provided at positions corresponding to the openings 105, 105 ...
8 and 108 and openings 109 and 109 for extracting ions are formed.

Then, the electrostatic recording head 101 applies an alternating electric field to the drive electrodes 103 and a DC voltage to the screen electrodes 107 as shown in FIG. Also, control electrode 1
A high voltage corresponding to the image signal is selectively applied to 04, 104 ... In a pulsed manner.

By doing so, a creeping corona discharge is generated in the openings 105, 105, between the drive electrodes 103, 103, ... And the control electrodes 104, 104, to which the voltage is selectively applied, as shown in FIG. The ion stream generated by the creeping corona discharge is accelerated or absorbed by the electric field formed between the control electrodes 104, 104 ... And the screen electrode 107, and the ion emission is controlled to control the dielectric drum 100. An electrostatic latent image by ions is formed on the upper surface in accordance with an image signal.

At that time, since the openings 105, 105 ... Of the control electrodes 104, 104 ... Which generate ions form a matrix, by controlling the emission of ions from these openings 105, 105. ... and control electrodes 104, 1 so that a desired electrostatic latent image can be formed on the dielectric drum 100.
04 ... is driven as follows in synchronization with the rotation of the dielectric drum 100.

That is, as shown in FIG. 16, an encoder 110 is attached to the rotation shaft of the dielectric drum 100, and the rotation speed of the dielectric drum is detected by this encoder 110. Then, while the pulse from the encoder 110 is output for one cycle T, as shown in FIG.
.. are sequentially driven one by one with a predetermined pulse width Tw, and a pulse voltage is applied to the control electrodes 104, 104 ..

By doing so, the drive electrode 10 to which the voltage is applied is
Opening 10 between 3, 103 ... And control electrodes 104, 104 ...
A creeping corona discharge is generated on 5, 105, and the ion current generated by this creeping corona discharge is applied to the control electrodes 104, 104 ...
It is accelerated or absorbed by an electric field formed between the screen electrode 107 and the screen electrode 107, and the emission of ions is controlled to form an electrostatic latent image by ions on the dielectric drum 100 according to an image signal.

For example, when a linear image is recorded by the electrostatic recording head 101, as shown in FIG. 22, the drive electrodes 103, 103, ... Are sequentially synchronized with the rising edge of the output pulse from the encoder 110. While applying an alternating electric field, a pulse voltage is applied to the control electrodes 104, 104 ... In synchronization with the drive electrodes 103, 103. That is, the control electrode is turned on when the No. 1 drive electrode is driven first. Next, the electrostatic latent image formed at that time is transferred to the dielectric drum 10
With the movement of 0, the control electrode is turned on when it comes under the No. 2 drive electrode (while the movement is in progress, the control electrode is turned off.) By repeating this operation, the dielectric drum As shown in FIG. 23, a linear electrostatic latent image is formed on 100 as the dielectric drum 100 moves.

In this way, the electrostatic latent image formed on the dielectric drum 100 is developed into a toner image by the developing unit 111, and the toner image is formed between the dielectric drum 100 and the pressure roller 112 that is in pressure contact with the dielectric image. On the recording paper 113 supplied to the nip part of
An image is recorded on the recording sheet 113 by fixing the image at the same time as the transfer by the pressure. In the figure, 114 is a cleaner for removing the toner remaining on the surface of the dielectric drum 100 after the toner image is transferred and fixed as described above, and 115 is a static eliminator for erasing the electric charges remaining on the surface of the dielectric drum 100. Are shown respectively.

[Problems to be Solved by the Invention]

However, the above conventional technique has the following problems. That is, in the case of the electrostatic recording device,
The toner image formed on the surface of the dielectric drum 100 is transferred and fixed onto the recording paper 113 by the pressure between the dielectric drum 100 and the pressure roller 112 that is in pressure contact with the dielectric drum 100. Therefore, when the recording paper 113 enters the nip portion between the dielectric drum 100 and the pressure roller 112 as shown in FIG. 24 (A), the pressure contact pressure between the dielectric drum 100 and the pressure roller 112 is instantaneous. Therefore, the rotation speed of the dielectric drum 100 instantaneously decreases as shown in A of FIG. 25, and then the vibration is repeated to return to the original speed. Then recording paper
While 113 passes through the nip portion between the dielectric drum 100 and the pressure roller 112 as shown in FIG. 24 (B), the rotation speed of the dielectric drum 100 is constant as shown in FIG. 25B. Maintain a predetermined speed. Then, when the recording paper 113 exits the nip portion between the dielectric drum 100 and the pressure roller 112 as shown in FIG. 24 (C), the pressure contact pressure between the dielectric drum 100 and the pressure roller 112 is momentarily. Since the rotation speed of the dielectric drum 100 becomes low, the rotation speed of the dielectric drum 100 instantaneously rises as shown in C of FIG. 25, and then the vibration is repeated to return to the original speed.

In this way, the rotation speed of the dielectric drum 100 is set to the recording paper 1
When 13 passes through the nip portion between the dielectric drum 100 and the pressure roller 112, it greatly fluctuates. Therefore, the dielectric drum 100
As shown in FIG. 26, the output pulse of the encoder 110 for determining the drive timing of the electrostatic recording head 101 by detecting the rotation speed of the recording sheet 113 also has its cycle as the recording sheet 113 passes through the nip portion. T changes.

On the other hand, the drive signal of the electrostatic recording head 101 output based on the output signal from the encoder 110 has its output synchronized with the rising edge of the output pulse from the encoder 110, as shown in FIG. Each driving electrode is started with a constant pulse width T _W and a constant interval Td set in advance.
It is output in the state of a pulse signal so as to sequentially drive 103, 103 ...

As a result, the rotation speed of the dielectric drum 100 is set to the recording paper 113.
When the cycle of the output pulse of the encoder 110 becomes longer than a predetermined interval as the speed of the encoder 110 passes through the nip portion of the, the head drive signal becomes relatively slow as shown in FIG. Is shortened by Δt1. Also a dielectric drum
When the rotation speed of 100 rises above the predetermined speed and the output signal of the encoder 110 becomes shorter than the predetermined interval, the 26th
As shown in the figure, the head drive signal becomes relatively longer by Δt2.

Therefore, the interval of the dot-like ions emitted from the openings 109, 109 of the electrostatic recording head 101 driven by the head drive signal is not synchronized with the rotation of the dielectric drum 100, and As shown in FIG. 27, the image recorded on the image (for example, when the character of “Kanji” is being recorded by the electrostatic recording head 101) is irregular as the recording paper 113 passes through the nip portion. However, there is a problem in that the image quality is deteriorated due to various disturbances.

[Means for Solving the Problems]

Therefore, the present invention has been made in order to solve the above-mentioned problems of the prior art, and an object of the present invention is to allow a recording member to project into a nip portion between a latent image carrier and a pressure roller pressed against the latent image carrier. Even if the rotational speed of the latent image carrier fluctuates due to such factors, by controlling the drive timing of the electrostatic recording head, it is possible to record high-quality images without causing image distortion. An object is to provide an electronic recording method and an apparatus thereof.

That is, according to the electrostatic recording method of the present invention, the electrostatic latent image is recorded on the rotating latent image carrier by the electrostatic recording head that records the electrostatic latent image by emitting ions in a matrix according to the image signal. In an electrostatic recording method in which an image is formed and the electrostatic latent image is developed to record the image, the rotational speed of the latent image carrier is detected and the rotational speed of the latent image carrier is changed. Is configured to control the drive timing of the electrostatic recording head.

The electrostatic recording apparatus according to the present invention includes an electrostatic recording head that discharges ions in a matrix according to an image signal to record an electrostatic latent image, and an electrostatic recording head formed by the electrostatic recording head. Based on a rotatable latent image carrier that carries a latent image, pulse generating means that generates a pulse at a predetermined cycle in accordance with the rotation of the latent image carrier, and a cycle of pulses output from the pulse generating means. An output control pulse generating means for generating an output control pulse of the electrostatic recording head,
And a control means for controlling the output of the output control pulse from the output control pulse generation means based on the cycle of the pulse output from the pulse generation means. As the control means, for example, the period of the pulse output from the pulse generation means is measured, and 1 / n of the measured pulse period (where n is a number characterizing the matrix of the electrostatic recording head) is calculated. 1 / n cycle measuring means for calculating and 1 measured by the 1 / n cycle measuring means
/ n period is used to subtract a pulse width of a predetermined output control pulse to obtain an output interval of the output control pulse.

Further, as the control means, in addition to those described above, a cycle measuring means for measuring the cycle of the pulse output from the pulse generating means, and an output control pulse optimum for the cycle measured by the cycle measuring means You may use what is equipped with the memory | storage means which memorize | stores a period.

Furthermore, as the control means, for example, when the cycle of the pulse output from the pulse generation means is shorter than a predetermined value, a control means for controlling the output control pulse to be output according to a predetermined pattern. used.

The present invention forms an electrostatic latent image on a rotating latent image carrier by an electrostatic recording head that ejects ions in a matrix according to an image signal to record an electrostatic latent image. After the electrostatic latent image is developed and visualized, the visualized developed image is provided on the recording member supplied to the nip portion between the latent image carrier and the pressure roller pressed against the latent image carrier, In an electrostatic recording method of recording an image in an electrostatic recording method of recording an image by transferring and fixing by pressure,
Although it is particularly effective, the present invention is not limited to this, and it is needless to say that the present invention can be applied to a device other than the device for recording an image by transferring and fixing the developed image visualized on the latent image carrier. Is.

[Action]

In the electrostatic recording method according to the present invention, the rotational speed of the latent image carrier is detected, and the drive timing of the electrostatic recording head is controlled according to the change in the rotational speed of the latent image carrier. Therefore, even if the rotational speed of the latent image carrier changes due to the recording member passing through the nip portion between the latent image carrier and the pressure roller that is in pressure contact with the latent image carrier, Since the drive timing of the electrostatic recording head is controlled according to the change in the moving speed, the electrostatic recording head can be driven always in synchronization with the rotation speed of the latent image carrier.

Further, in the electrostatic recording apparatus according to the present invention, an electrostatic recording head for discharging ions in a matrix according to an image signal to record an electrostatic latent image, and an electrostatic recording head formed by the electrostatic recording head. A rotatable latent image carrier that carries an electrostatic latent image, a pulse generation unit that generates a pulse at a predetermined cycle in accordance with the rotation of the latent image carrier, and a pulse cycle output from the pulse generation unit. Output control pulse generating means for generating an output control pulse of the electrostatic recording head based on the above, and output control output from the output control pulse generating means based on the cycle of the pulse output from the pulse generating means And a control means for controlling the output of the application pulse, the pulse generation means detects the rotational speed of the latent image carrier, and outputs from the pulse generation means. In order to control the output of the output control pulse from the output control pulse generating means by the control means based on the cycle of the generated pulse, the nip between the latent image carrier and the pressure roller pressed against the recording member Even if the rotational speed of the latent image carrier fluctuates by passing through the section, the head drive signal does not become shorter by Δt1 nor longer by Δt2 as shown in FIG. The electrostatic recording head can always be driven in synchronization with the rotation speed of the latent image carrier.

〔Example〕

 The present invention will be described below based on the illustrated embodiments.

FIG. 2 shows an embodiment of the electrostatic recording apparatus according to the present invention. In the figure, reference numeral 1 denotes a dielectric drum as a latent image carrier, and the dielectric drum 1 can be rotated in the direction of the arrow by a driving means (not shown). An electrostatic recording head 2 is arranged above the dielectric drum 1 so as to face each other with a predetermined gap.

As shown in FIG. 3, the electrostatic recording head 2 includes a first insulating substrate 3 having a rectangular shape in plan view. As shown in FIG. 4, a plurality of linear drive electrodes 4, 4, ... Are provided in parallel with each other on the front surface of the first insulating substrate 3, and on the back surface of the insulating substrate 3, Drive electrodes 4, 4 ...
A plurality of control electrodes 5, 5, ... Are provided so as to intersect with, and a matrix is formed by both electrodes 4, 4 ,. As shown in FIGS. 3 and 4, in the control electrodes 5, 5, ..., Circular openings 6, which serve as spatial regions in which a corona discharge along the road is generated, at positions intersecting with the drive electrodes 4, 4 ,. 6 ... are provided. Since the drive electrodes 4, 4, ... And the control electrodes 5, 5, ... Form a matrix, these openings 6, 6, ... Are provided at the intersections of these electrodes 4, 4 ,. The openings 6, 6 ... Also form a matrix as shown in FIG. Then, the first insulating substrate 3, the drive electrodes 4, 4, ... And the control electrodes 5, 5, ... Form an ion generating section 7 as shown in FIG.

As shown in FIG. 5, a spacer layer 8 serving as a second insulating substrate is formed on the lower surface of the control electrodes 5, 5, ... Of the ion generator 7.
The screen electrode 9 is provided with the intervening. As shown in FIG. 6, the spacer layer 8 is formed in a plane rectangular shape having a length that is substantially the same as that of the first insulating substrate 3 and a width that is slightly narrower. Three
Is stuck to. As shown in FIG. 5, the spacer layer 8 has openings 10, 10 larger than the openings 6, 6 ... at positions corresponding to the openings 6, 6 ,.
... is provided. The screen electrode 9 is also provided with openings 11, 11 ... As ion derivation regions at positions corresponding to the openings 6, 6 ... Of the control electrodes 5, 5.

In FIG. 4, reference numeral 12 denotes a head substrate that covers the surfaces of the drive electrodes 4, 4, ....

Further, as will be described later, a pulsed drive signal is applied to the drive electrodes 4 and the control electrodes 5, and the drive electrodes 4, 4, ... And the control electrodes to which a voltage is selectively applied. As shown in FIG. 7, creeping corona discharge R is generated in the openings 6, 6 between the creeping corona discharge 5 and the ion current S generated by the creeping corona discharge.
6 is accelerated by an electric field formed between the screen electrode 9 and the screen electrode 9, and the ion flow S is controlled and emitted from the openings 11, 11 ...
To form an electrostatic latent image according to the image signal.

The head drive signal applied to the drive electrode 4 and the control electrode 5 is composed of a drive electrode signal and a control electrode signal, as will be described later, and an opening portion to which both electrode signals are applied at the same time.
Ions are ejected in a dot shape only from 11, 11. In FIG. 8, when the pulse voltage is simultaneously applied to the first drive electrode 4 and the first control electrode, the dot d1 is printed. Then, as will be described later, while the encoder outputs one pulse, the drive electrode signals are from the 1st to the nth (n is the number of drive electrodes 4; 5 in the illustrated example) at a predetermined interval Td. The dots d1, d2, d3, d4, d5 are sequentially printed because the control electrodes are driven sequentially and are driven in synchronization with their respective timings. Then, by the next pulse from the encoder accompanying the rotation of the dielectric drum 1, the dots are sequentially driven from the first drive electrode, and the dot d6 is printed at a position on the upstream side of the dot d1 as the dielectric drum 1 rotates. To be done. After that, the pulses are sequentially printed as d11, d16, d21, d26, d31, d36, d41 for each pulse output from the encoder as the dielectric drum 1 rotates. As a result, the d41'th dot is printed side by side next to d5 'printed fifth by the first pulse from the encoder.

By driving the drive electrodes 4 and the control electrodes 5 forming the matrix as described above, for example, letters of the alphabet F are printed as shown in FIG.

Thus, the electrostatic recording head 2 causes the dielectric drum 1 to move.
The electrostatic latent image formed on the surface of is, as shown in FIG.
The toner image is visualized by the developing device 16 arranged on the side of the dielectric drum 1 to form a toner image. The toner image formed on the surface of the dielectric drum 1 is fixed at the same time as being transferred onto the recording paper 17 supplied in synchronization with the rotation of the dielectric drum 1 from a paper feeding device (not shown).

Transfer and fixing of the toner image is performed as follows.
That is, the pressure roller 18 is pressed against the surface of the dielectric drum 1 at a predetermined pressure (for example, 150 to 200 kg / cm ² ),
By supplying the recording paper 13 to the nip portion between the dielectric drum 1 and the pressure roller 18, the toner image formed on the dielectric drum 1 is simultaneously fixed onto the recording paper 17 by the pressure transfer. Has become.

As described above, the cleaner 19 removes the toner and the like remaining on the surface of the dielectric drum 1 for which the toner image transfer and fixing process has been completed, and the static eliminator 20 erases the charges remaining on the surface.

By the way, in this embodiment, a pulse generating means for generating a pulse at a predetermined cycle with the rotation of the latent image carrier is provided. That is, the dielectric drum 1
As shown in FIG. 10, an encoder 22 as a pulse generating means is attached to the rotary shaft 21 thereof, and the encoder 22 detects the rotational speed or position of the dielectric drum 1. There is.

As shown in FIG. 11, the encoder 22 is fixed to the rotary shaft 21 of the dielectric drum 1, and a rotary disk 23 having slits 23a, 23a ... Engraved on its outer peripheral edge at a predetermined pitch. The slits 23a, 23 are arranged on the outer peripheral edge of the rotating disk 23.
Transmissive optical sensor 24 that optically detects the passage of a ...
And the output of this optical sensor 24 is amplified and the slits 23a, 23a
It is composed of an amplifier 25 that outputs a pulse signal synchronized with the passage of a.

The encoder 22 is a rotary shaft of the dielectric drum 1.
The optical sensor 24 detects the rotation of the rotary disc 23 fixed to the optical disc 21, and the amplifier 25 outputs a pulse signal in synchronization with the rotation of the rotary disc 23 to determine the rotational speed or position of the dielectric drum 1. It is designed to detect.

The block diagram in FIG. 2 shows the signal processing unit of the electrostatic recording apparatus according to this embodiment. In the figure, 26 is an image memory for storing print data sent from a host computer (not shown), and 27 is print data stored in the image memory 26 for the drive electrodes 4, 4, ... And control electrodes of the electrostatic recording head 2. A data assembler for rearranging according to a matrix of 5, 5, ..., 28 is an image buffer for temporarily holding print data sent from the data assembler 27 to the electrostatic recording head 2, and 29 is an electrostatic recording head 2.
, A timing generator for generating a timing signal for driving based on the print data held in the image buffer 28, and 30 is a predetermined voltage applied to the drive electrodes 4, 4 ... Reference numeral 31 denotes a drive circuit for applying a voltage to drive the drive circuit, and reference numeral 31 denotes a control circuit for controlling a timing signal for driving the electrostatic recording head 2 in accordance with a signal from the encoder 22.

FIG. 12 further shows the configuration of the control circuit in detail. In the figure, 32 is a timing signal generation circuit for generating a predetermined timing signal, 33 is a pulse width Tw of a pulse voltage applied to the drive electrodes 4, 4 ... Or the control electrodes 5, 5 ... Of the electrostatic recording head 2. A pulse width setting circuit 34 measures the period T of the pulse signal output from the encoder 18 based on a reference clock, and obtains 1 / n of this period T T / n
Cycle measurement circuit, 35 is a subtraction circuit for subtracting the pulse width Tw set by the pulse width setting circuit 33 from the T / n cycle measured by the T / n cycle measurement circuit 34, and 36 is initially stored A FIFO memory circuit that outputs signals in sequence, 37 is an encoder that stores the signals stored in this FIFO memory circuit 36.
Number of lines n for pulse signals input sequentially from 22
It is an n-line setting circuit that decides whether to output with a delay.

The output pulse 40 from the encoder 22, the output signal 41 of the pulse width setting circuit, and the output signal 42 from the FIFO memory circuit 36 are all output to the timing generator 29.

With the above configuration, the electrostatic recording apparatus according to this embodiment electrostatically records an image as follows. That is, as shown in FIG. 2, the print data sent from the host computer (not shown) and written in the image memory 26 is rearranged by the data assembler 27 in accordance with the matrix of the electrostatic recording head 2 and the image buffer 28. Entered in. And this image buffer 28
The print data input to is output to a drive circuit 30 according to a timing signal generated by a timing generator 29, and the drive circuit 30 drives the electrostatic recording head 2 to record an electrostatic latent image. Is done.

At that time, the generation of the timing signal by the timing generator 29 is controlled by the control circuit 31 as follows.
That is, the control circuit 31 changes the cycle T of the pulse signal 40 output from the encoder 22 to T /
The n-cycle measuring circuit 34 performs measurement based on the reference clock and calculates a T / n cycle corresponding to 1 / n of the cycle T of the pulse signal 40. And this T / n period measurement circuit
Pulse signal 40 from encoder 22 determined by 34
The T / n period signal is input to the subtraction circuit 35, and is subtracted from the pulse width Tw preset in the pulse width setting circuit 33 by the subtraction circuit 35 to obtain the interval Td between the pulse signals. The interval Td between the pulse signals is sent to the FIFO memory circuit 36 and temporarily stored therein, and the signals are output from the FIFO memory circuit 36 in the order in which they are initially stored. At that time, the above FIFO
The signal 42 output from the memory circuit 36 is delayed by the number of lines n set by the n line setting circuit 37 with respect to the pulse signal 40 sequentially input from the encoder 22. In addition, the interval Td between the pulse signals
At the same time, the pulse width Tw preset in the pulse width setting circuit 33 and the output pulse T from the encoder 22 are output to the timing generator 29.

Therefore, in the timing generator 29, the control circuit 31
Based on the interval Td between the pulse signals sent from, the pulse width Tw preset in the pulse width setting circuit 29, and the output pulse T from the encoder 18, the timing of the print data is generated as follows.

That is, the drive signal of the electrostatic recording head 2 is composed of the drive electrode signal 38 and the control electrode signal 39 as shown in FIG. 13, and the drive electrode signal 38 and the control electrode signal 39 are turned on at the same time. When it is turned on, a latent image is printed. Then, the drive electrode signal 38 is sequentially turned on, such as the first drive electrode 41, the second drive electrode 42, and the third drive electrode 43, in synchronization with the rising edge of the output pulse T from the encoder 22. . At that time, the drive electrode signal 38 is not simply sequentially turned on based on the preset pulse width, but is synchronized with the rising of the output pulse T from the encoder 22 and the first drive electrode signal 381. Is turned on for the pulse width Tw, but when the interval Td between the pulse signals sent from the control circuit 31 has elapsed thereafter, the second drive electrode signal 382 is turned on for the pulse width Tw. Thereafter, the same process is repeated to print the latent image of one line. At that time, the control electrode 5 receives the control electrode signal 39 according to the print data and in synchronization with the drive electrode signal 38.
Is applied in pulse form.

By the way, as shown in FIG. 12, the interval Td between the pulse signals sent from the control circuit 31 is obtained by dividing the period T of the pulse signal from the encoder 22 into n equal parts T / n to the pulse width T.
It is the w subtracted. Therefore, the value obtained by adding the pulse width Tw and the interval Td between the pulse signals and multiplying by n is equal to the period T of the pulse signal from the encoder 22, that is, (Tw + Td)
× n = T. Therefore, even if the period T of the pulse signal from the encoder 22 changes due to uneven rotation of the dielectric drum 1 or the like, the head drive signals 38 and 39 are always output from the encoder 2
Since the pulse signal from 2 is output in accordance with the change of the cycle T, and also in conformity with the cycle T, the encoder
Even if the period T of the pulse signal from 22 changes, the recorded electrostatic latent image is not disturbed.

As described above, in the electrostatic recording apparatus according to this embodiment, the electrostatic recording head 2 that records the electrostatic latent image by ejecting ions in a matrix according to the image signal, and the electrostatic recording head 2 And a rotatable dielectric drum 1 that carries an electrostatic latent image formed by the above, and an encoder 22 that generates a pulse at a predetermined cycle T as the dielectric drum 1 rotates.
And a timing generator 29 for generating an output control pulse of the electrostatic recording head 2 based on the period of the pulse T output from the encoder 22, and a period T of the pulse output from the encoder 22. Since the control circuit 31 for controlling the drive electrode signal 38 and the control electrode signal 39 output from the timing generator 29 is provided, the rotation speed of the dielectric drum 1 is detected by the encoder 22. Based on the period T of the pulse output from the encoder 22, the control circuit 31 controls the output of the drive electrode signal 38 and the control electrode signal 39 output from the timing generator 29. Even if the rotation speed of the dielectric drum 1 fluctuates by passing through the nip portion between the body drum 1 and the pressure roller 18 pressed against the body drum 1, the It is possible to drive the electrostatic recording head 2 in synchronization with the rotation speed of the drum 1. Therefore, it is possible to record a high quality image without causing a disorder or the like in the recorded image.

FIG. 14 shows another embodiment of the present invention. When the same parts as those of the above embodiment are designated by the same reference numerals and explained, in this embodiment, the rotation speed of the dielectric drum is predetermined. All the drive signals can be output to the electrostatic recording head even when the speed becomes higher than the speed and the cycle T of the pulse output from the encoder becomes shorter than a predetermined value.

That is, when the rotation speed of the dielectric drum 1 becomes higher than the predetermined speed and the cycle T of the pulse output from the encoder 22 becomes shorter than the predetermined value, the pulse width Tw is constant, and therefore the timing generator 29. Even if the interval Td between the pulse signals output from is output to zero, all drive signals can be output during the period T of the pulses output from the encoder 22, as shown in FIG. 15 (b). Can not
The recorded image may be chipped.

Therefore, in this embodiment, even if the period T of the pulse 40 output from the encoder 22 becomes shorter than a predetermined value, all the drive signals are output during the period T of the pulse output from the encoder 22. To enable this, the pulse width Tw and the interval Td between the pulse signals are changed depending on whether 1 / n of the period T of the output pulse from the encoder 22 is a predetermined value or less.

FIG. 14 is a block diagram showing the control circuit. In the figure, 50 is a limit setting circuit for setting a value T0 that determines whether the circuit of this embodiment operates when the cycle T of the output pulse from the encoder 22 becomes a predetermined value T0 or less, and 51 is this limit setting circuit 50. Calculate the value of 1 / n of the value T0 set in T0 / n
A table conversion circuit, 52 is a comparator for comparing the value T / n output from the T / n cycle measuring circuit 34 with the value T0 / n output from the previous period T0 / n table conversion circuit 51, and 53 is a comparator 52. The output from the first pulse width setting circuit 54
And selectors for switching between the second pulse width setting circuit 55 and the second pulse width setting circuit 55, respectively.

In this embodiment, when the pulse output from the encoder 22 is input to the control circuit 31, 1 / n of the period T of this pulse is T
/ n is measured by the cycle measuring circuit 34, this value T / n is set in the limit setting circuit 50 by the comparator 52,
The value T0 / n converted by the T0 / n table conversion circuit 51 is compared, and if the value T / n is larger than the value T0 / n, the output signal from the comparator 52 causes the selector 53 to output the first pulse. The width setting circuit 54 is selected, and the electrostatic recording head 2 has the same pulse width Tw1 and pulse interval Td1 set in the first pulse width setting circuit 54 as in the above embodiment.
It is driven as shown in FIG.

On the other hand, when the value T / n is less than or equal to the value T0 / n, the output signal from the comparator 52 causes the selector 53 to output the second value.
Pulse width setting circuit 55 is selected, and the electrostatic recording head 2 is driven by the pulse width Tw2 set in the second pulse width setting circuit 55. The pulse width Tw2 is set shorter than the pulse width Tw1 set in the first pulse width setting circuit 54.

By doing so, even if the period T of the pulse 40 output from the encoder 22 becomes shorter than a predetermined value,
As shown in FIG. 15 (c), by setting the pulse width of the pulse for driving the drive electrode 4 and the like to a pulse width Tw2 shorter than usual, and shortening the interval Td2 between the pulses accordingly, the encoder It is possible to output all the head drive signals during the period T of the pulse output from 22, and it is possible to prevent the occurrence of defects in the recorded image.

Since other configurations and operations are the same as those in the above embodiment,
The description is omitted.

[Advantages of the Invention] The present invention has the above-described configuration and action, and the rotational speed of the latent image bearing member is increased by the protrusion of the recording member into the nip portion between the latent image bearing member and the pressure roller pressed against the latent image bearing member. Provided is an electrostatic recording method and apparatus capable of recording a high-quality image without causing image disturbance by controlling the drive timing of the electrostatic recording head even when fluctuation occurs. it can.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the principle of the electrostatic recording method according to the present invention, and FIG. 2 is a configuration diagram showing an electrostatic recording device to which the electrostatic recording device according to the present invention can be applied, FIGS. 3 and 4. FIG. 5 is a plan view and a cross-sectional view showing the ion generating part of the electrostatic recording head,
6 and 6 are sectional views and plan views showing the electrostatic recording head, and FIG. 7 is a sectional view showing the operation of the electrostatic recording head, and FIG.
FIGS. 9 and 10 are explanatory views showing the recording operation of the electrostatic recording head, FIG. 10 is a perspective view showing the end of the dielectric drum, FIG. 11 is a block diagram showing the encoder, and FIG. 12 is a control. FIG. 13 is a block diagram showing the circuit, FIG. 13 is a timing chart showing the operation of the control circuit, FIG. 14 is a block diagram of the control circuit showing another embodiment of the present invention, and FIGS. 15 (a), (b),
FIG. 16C is a timing chart showing the operation of the embodiment, FIG. 16 is a configuration diagram showing a conventional electrostatic recording device, and FIG.
18 and 19 are a plan view and a sectional view showing an ion generating portion of the electrostatic recording head, FIGS. 19 and 20 are a plan view and a sectional view showing the electrostatic recording head, and FIG. 21 is an electrostatic recording head. 22 and 23 are timing charts and explanatory views showing the recording operation of the electrostatic recording head, and FIG.
24 (A), (B), and (C) are explanatory views showing a state in which the recording paper passes through the nip portion of the dielectric drum and the pressure roller, and FIG. 25 shows the fluctuation of the rotation speed of the dielectric drum. FIG. 26 is a graph, FIG. 26 is an explanatory diagram showing a recording operation, and FIG. 27 is an explanatory diagram showing a recorded image. [Description of symbols] 1 ... Dielectric drum 2 ... Electrostatic recording head 4 ... Drive electrode 5 ... Control electrode 11 ... Opening 22 ... Encoder 31 ... Control circuit 34 ... T / n period measurement Circuit 35 ... Subtraction circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akimasa Komura 2274 Hongo, Ebina City, Kanagawa Fuji Xerox Co., Ltd. Ebina Works (56) References JP-A-60-216357 (JP, A)

Claims (4)

[Claims] 1. An electrostatic latent image is formed on a rotating latent image carrier by an electrostatic recording head which records an electrostatic latent image by ejecting ions in a matrix according to an image signal, and the electrostatic latent image is formed. In an electrostatic recording method for developing an electrostatic latent image to record an image, the rotational speed of the latent image carrier is detected, and an electrostatic recording head is driven according to the change in the rotational speed of the latent image carrier. An electrostatic recording method characterized by controlling timing. 2. An electrostatic recording head for recording an electrostatic latent image by emitting ions in a matrix according to an image signal, and a rotatable rotatable electrostatic latent image formed by the electrostatic recording head. A latent image carrier, pulse generating means for generating a pulse at a predetermined cycle with the rotation of the latent image carrier, and the electrostatic recording head of the electrostatic recording head based on the cycle of the pulse output from the pulse generating means. Output control pulse generating means for generating output control pulses; and control means for controlling the output of the output control pulses from the output control pulse generating means based on the cycle of the pulses output from the pulse generating means. An electrostatic recording device comprising: 3. The control means measures the period of the pulse output from the pulse generating means, and 1 / n of the measured pulse period (where n characterizes the matrix of the electrostatic recording head). 1 / n period measuring means for calculating
It is characterized by further comprising: subtraction means for subtracting the pulse width of a predetermined output control pulse from the 1 / n cycle measured by the 1 / n cycle measurement means to obtain an output interval of the output control pulse. The electrostatic recording device according to claim 2. 4. The control means comprises limiter means for outputting an output control pulse according to a predetermined pattern when the period of the pulse output from the pulse generating means is shorter than a predetermined value. The electrostatic recording apparatus according to claim 2, wherein: