JP2926930B2 - Electrostatic recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic recording device used for a printer, a facsimile, and the like, and particularly to a case where a failure occurs in an electrostatic recording head during an image recording operation. The present invention relates to a compatible electrostatic recording device.

[Conventional technology]

Conventionally, the electrostatic recording device includes the following. That is, as shown in FIG. 23, the electrostatic recording head 101 is arranged so as to face the surface of the dielectric drum 100,
A desired electrostatic latent image is formed on the surface of the dielectric drum 100 by the electrostatic recording head 101.

As shown in FIGS. 24 and 25, the electrostatic recording head 101 has 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, and a matrix is formed by the two electrodes 103, 103, and 104, 104. Then, the control electrode 10
Openings 105, 105 as discharge generation regions are formed in the 4, 104,... At positions intersecting the drive electrodes 103, 103,. The openings 105, 105,... Formed in these control electrodes 104, 104,.
Are provided at positions where the drive electrodes 103, 103... Constituting the matrix intersect with the control electrodes 104, 104..., As shown in FIG.
It constitutes a matrix.

Also, as shown in FIGS. 26 and 27, a screen electrode 107 is provided on the lower surface of the control electrodes 104, 104,... With an insulating layer 106 interposed therebetween. As shown in FIG. 27, the control electrode 10
At the positions corresponding to the openings 105, 105,
Are formed, and openings 109, 109 for deriving ions are formed.

Then, the electrostatic recording head 101 applies an AC voltage between the drive electrode 103 and the screen electrode 107 and also applies a DC voltage to the screen electrode 107, as shown in FIG. Further, a pulse voltage according to an image signal is selectively applied to the control electrodes 104, 104,...

As a result, as shown in FIG. 28, creeping corona discharge is caused in the openings 105, 105 between the drive electrodes 103, 103, to which the voltage is selectively applied, and the control electrodes 104, 104,. , And accelerates or absorbs the ion flow generated by the creeping corona discharge by an electric field formed between the control electrodes 104, 104,. An electrostatic latent image due to ions is formed thereon in accordance with an image signal.

The electrostatic latent image formed on the dielectric drum 100
As shown in FIG. 3, the toner image is developed by a developing device 111, and the toner image is supplied to a nip portion between the dielectric drum 100 and a pressure roller 112 which is in pressure contact with the dielectric drum 100.
On the recording paper 113, an image is recorded by simultaneously fixing the image on the recording paper 113 with the transfer by pressure. In the figure, reference numeral 114 denotes the dielectric drum 100 after the toner image is transferred and fixed as described above.
Cleaner that removes toner remaining on the surface of
Denotes a static eliminator for erasing electric charges remaining on the surface of the dielectric drum 100.

[Problems to be solved by the invention]

However, the prior art has the following problems. That is, the electrostatic recording device selectively applies a DC voltage between the driving electrode 103 and the screen electrode 107 of the electrostatic recording head 101 and a DC voltage to the screen electrode 107, thereby selectively changing the voltage. A creeping corona discharge is generated in the openings 105, 105 between the applied drive electrodes 103, 103 ... and the control electrodes 104, 104 ..., and an ion flow generated by the creeping corona discharge is formed on the screen electrode 107. Are discharged from the openings 109, 109 ... to form an electrostatic latent image. Therefore, in the electrostatic recording head 101, the openings 109, 109 of the screen electrode 107 that emits the ion current are clogged by paper dust or the like, or the drive electrodes 103, 103, and the control electrodes 104, 104 are disconnected. Occurs, the openings 109, 109 ...
Ions are no longer emitted in response to the image signal,
The recorded electrostatic latent image is chipped. Therefore, there has been a problem that the reproducibility of an image essentially required for an electrostatic recording device used as a printer or the like cannot be secured.

In particular, when the electrostatic recording apparatus is used as an output printer such as a computer that continuously records images in large quantities, the openings 109 of the screen electrode 107 in the electrostatic recording head 101 are clogged. When this occurs, there is a problem that a large amount of printed matter having a bit defect that is not printed on the recorded image is generated.

[Means for solving the problem]

Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to perform recording even when clogging or the like occurs in an opening of a screen electrode in an electrostatic recording head. An object of the present invention is to provide an electrostatic recording apparatus capable of preventing a large amount of printed matter having a bit defect that is not printed on an image from being generated.

That is, the present invention provides an ion generating section formed by laminating a plurality of drive electrodes and a plurality of control electrodes on an insulating substrate in a matrix with a first insulating layer interposed therebetween, and a control electrode side of the ion generating section. An electrostatic recording head having an ion flow control unit composed of a screen electrode laminated with a second insulating layer interposed therebetween, and an electrostatic latent image carrier for carrying an electrostatic latent image formed by the electrostatic recording head Developing means for making the electrostatic latent image formed on the electrostatic latent image carrier a remarkable image; and intersection of a plurality of drive electrodes and a plurality of control electrodes with the electrostatic recording head at a predetermined timing. Of the ion generating units formed in a matrix in the unit, at least the adjacent ion generating units do not simultaneously emit the ion current, but output a test pattern that emits the ion current independently from each ion generating unit. Test pad And over emissions output means it is configured to include a failure detection means for detecting a failure of the electrostatic recording head is detected and the electrostatic recording head the operating state of which is based on the output of the test pattern output means.

As the test pattern output means, for example, a means for outputting a test pattern for each drive electrode of an electrostatic recording head is used.

Further, as the failure detecting means, a means for detecting a failure by detecting the density of a developed image formed on an electrostatic latent image carrier and visualized by an output from a test pattern output means, for example, is used. However, the present invention is not limited to this. As the failure detecting means, a means for detecting a charge amount of ions emitted from the electrostatic recording head by an output from the test pattern output means and detecting a failure is used. Of course, it is good.

Further, the timing at which a test pattern is output from the test pattern output means is set, for example, every time a fixed number of sheets are recorded.

Further, a means for notifying the failure when the failure is detected by the failure detection means may be provided.

[Action]

In the present invention, a test pattern output unit that outputs a test pattern to the electrostatic recording head at a predetermined timing, and an operation state of the electrostatic recording head based on an output of the test pattern output unit is detected to detect the electrostatic state of the electrostatic recording head. Since it is configured to include a failure detection unit that detects a failure of the recording head, a test pattern is output to the electrostatic recording head by the test pattern output unit at a predetermined timing, and the electrostatic latent image is output by the electrostatic recording head. An image recording operation is performed, an operation state of the electrostatic recording head is detected based on an output of the test pattern output unit, and a failure of the electrostatic recording head is detected by a failure detection unit.

Further, according to the present invention, the test pattern output from the test pattern output means may be formed in at least an adjacent one of the ion generators formed in a matrix at the intersection of the plurality of drive electrodes and the plurality of control electrodes. Since this is a test pattern that outputs a test pattern that emits an ion current independently from each ion generation unit without simultaneously discharging an ion flow from the unit, the ion flow is output independently from at least the adjacent ion generation units. By detecting the test pattern formed by discharge, when the electrostatic recording head is used, clogging or the like occurs in any of the openings of the screen electrode of the electrostatic recording head, and the test pattern is discharged from the ion generation unit. For example, when the amount of ions in the ion stream is reduced, it is possible to reliably detect this and detect a failure of the electrostatic recording head.

〔Example〕

 Hereinafter, the present invention will be described based on the illustrated embodiment.

FIG. 1 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
It is rotatable in the direction of the arrow by driving means (not shown). An electrostatic recording head 2 is disposed above the dielectric drum 1 so as to face the same at a predetermined interval.

As shown in FIG. 2, the electrostatic recording head 2 includes a first insulating substrate 3 having a rectangular shape in a plane. As shown in FIG. 2, a plurality of linear drive electrodes 4, 4,... Are provided in parallel with each other on the surface of the first insulating substrate 3, and on the back surface of the insulating substrate 3, Drive electrode 4, 4
Are provided so as to intersect with..., And a matrix is formed by the two electrodes 4, 4,. The control electrodes 5, 5,.
As shown in FIG. 3 and FIG. 3, circular openings 6, 6,... As space regions where creeping corona discharge occurs are provided at positions intersecting the drive electrodes 4, 4,. The openings 6, 6,... Are provided at the intersections of the electrodes 4, 4,. The openings 6, 6,... Also form a matrix, as shown in FIG. The first insulating substrate 3, the driving electrodes 4, 4,... And the control electrodes 5, 5,... Constitute an ion generating section 7, as shown in FIG.

The lower surfaces of the control electrodes 5, 5,...
As shown in FIG. 4, a screen electrode 9 is provided with a spacer layer 8 as a second insulating substrate interposed. As shown in FIG. 5, the spacer layer 8 is formed in a flat rectangular shape having a length substantially equal to that of the first insulating substrate 3 and a slightly narrower width. 3 is fixed. The spacer layer 8 includes a fourth
As shown in the figure, at positions corresponding to the openings 6, 6,... Of the control electrodes 5, 5,.
10, 10, ... are provided. Also, the screen electrode 9 is provided with openings 11, 11,... As ion extraction regions at positions corresponding to the openings 6, 6,. In FIG. 3, reference numeral 12 denotes a head substrate that covers the surfaces of the drive electrodes 4, 4,...

As shown in FIG. 4, an AC power supply 13 is connected between the drive electrode 4 and the screen electrode 9, and an AC voltage is applied between the electrodes 4 and 9 by the AC power supply 13. It has become so. On the other hand, the control electrodes 5, 5
, A pulse voltage is selectively applied by the ion control power supply 14, and a DC voltage is applied to the screen electrode 9 by the DC power supply 15. By doing so, the drive electrode 4, to which a voltage is selectively applied,
4 and the control electrodes 5, 5,.
Then, as shown in FIG. 6, a creeping corona discharge is generated,
The ion flow generated by the creeping corona discharge is accelerated or absorbed by an electric field formed between the control electrodes 6, 6,... And the screen electrode 9, and the ion flow is controlled and released from the screen electrode 11 by the dielectric. An electrostatic latent image by ions is formed on the body drum 1 according to an image signal.

As described above, the electrostatic recording head 2 allows the dielectric drum 1
As shown in FIG. 1, the electrostatic latent image formed on the surface of
The image is visualized by a developing device 16 disposed 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 the transfer onto a recording sheet 17 supplied in synchronization with the rotation of the dielectric drum 1 from a sheet feeding device (not shown).

The transfer and fixing of the toner image is performed as follows. That is, the surface of the dielectric drum 1 has a pressure roller
18 is pressed at a predetermined pressure (for example, 150 to 200 kg / cm ² ), and the nip between the dielectric drum 1 and the pressure roller 18 is
Pass the recording paper 13. By doing so, the toner image formed on the dielectric drum 1 can be simultaneously transferred and fixed onto the recording paper 17 by pressure.

The toner remaining on the surface of the dielectric drum 1 on which the toner image transfer / fixing step has been completed as described above is removed by the cleaner 19 and the charge remaining on the surface is erased by the charge remover 20.

By the way, in this embodiment, a test pattern output unit that outputs a test pattern to the electrostatic recording head at a predetermined timing, and an operation state of the electrostatic recording head based on an output of the test pattern output unit is detected to detect the operation state. It is configured to include a failure detection unit that detects a failure of the electrostatic recording head.

That is, as shown in FIG. 7, image data is sent to the electrostatic recording head 2 from a host computer or the like (not shown). The image data is input to the control circuit 21. The control circuit 21 outputs a timing signal for driving the electrostatic recording head 2 according to a signal from an encoder (not shown) that detects the rotation of the dielectric drum 1. Further, the timing signal from the control circuit 21 is output to the drive circuit 22. The drive circuit 22 drives the drive electrodes 4, 4,... And the control electrodes 5, 5,.

A test pattern output circuit 23 is connected to the control circuit 21, and a test pattern is output from the test pattern output circuit 23 to the electrostatic recording head 2 at a predetermined timing.

Further, as shown in FIG. 1, an optical head 24 constituting a failure detecting means is disposed around the dielectric drum 1 downstream of the developing device 16. This optical head 24
Has a built-in reflection type optical sensor, and detects the density of the toner image formed on the dielectric drum 1 by irradiating the surface of the dielectric drum 1 with light and measuring the intensity of the reflected light. Is what you do. The optical head 24 is arranged so as to be able to reciprocate along the axial direction of the dielectric drum 1 so that all the toner images formed on the dielectric drum 1 can be detected.

The optical head 24 includes an amplifier 25 as shown in FIG.
The output signal from the optical head 24 is amplified by the amplifier 25 and input to the failure determination circuit 26. The failure determination circuit 26 detects the operation state of the electrostatic recording head 2 based on the output of the test pattern output circuit 23, and detects a failure of the electrostatic recording head 2.

In the above configuration, in the electrostatic recording device according to this embodiment, a failure of the electrostatic recording head is detected as follows. That is, when normal image recording is performed by the electrostatic recording device, as shown in FIG. 7, the control circuit 21 drives the drive circuit in accordance with print data sent from the host computer or the like (not shown) to the control circuit 21. The electrostatic recording head 2 is driven in accordance with print data to form an electrostatic latent image on the dielectric drum 1. Then, the electrostatic latent image formed on the dielectric drum 1 is developed by a developing device 16 to form a toner image, and the toner image is formed in a nip portion between the dielectric drum 1 and a pressure roller 18 in pressure contact with the dielectric drum. An image is recorded on the recording sheet 17 by simultaneously fixing the image onto the recording sheet 17 supplied with the pressure and transfer.

By the way, in the electrostatic recording apparatus according to this embodiment, as shown in FIG. 7, the test pattern output circuit 23 outputs a predetermined test pattern to the electrostatic recording head 2 at a predetermined timing, for example, at every predetermined number of prints. Then, an electrostatic latent image of a test pattern is formed on the dielectric drum 1 by the electrostatic recording head 2.

While this test pattern is being output, for example, a Busy signal is transmitted from the electrostatic recording device to the host computer, and the host computer does not transmit print data while detecting the Busy signal. . When the failure detection based on the test pattern is completed, the electrostatic recording device stops sending the Busy signal to the host computer and outputs a Ready signal. When the host computer detects the Ready signal, the printing data of the print data is output. Restart output.

The electrostatic latent image of the test pattern formed on the dielectric drum 1 is developed by the developing device 16 to become a toner image.

As the test pattern, for example, the one shown in FIG. 9 is output. This test pattern shows the case where the number of the drive electrodes 4, 4,... Of the electrostatic recording head 2 is four, and the test pattern output circuit 23 outputs one drive electrode 4, 4,. Are sequentially applied, and at the same time, the voltage is continuously applied to all the control electrodes 5, 5,. In this way, the opening 1 of the first driving electrode 4 and the control electrodes 5, 5.
An ion stream is emitted from 1, 11,... For a predetermined time, and a linear test pattern 30− is formed along the circumferential direction of the dielectric drum 1.
1, 30-5, 30-9 ... are recorded. Next, an ion stream is emitted for a predetermined time from the openings 11, 11, ... intersecting all the control electrodes 5, 5, ... in correspondence with the second drive electrode 4, and the ion flow is directed along the circumferential direction of the dielectric drum 1, The linear test patterns 30-2, 30-6, 30-10,... Are recorded. as a result,
As shown in FIG. 8, a lattice-like ladder pattern is recorded on the surface of the dielectric drum 1.

As shown in FIG. 1, the toner image of the test pattern formed on the dielectric drum 1 is disposed downstream of the developing device 16 and optically scanned along the axial direction of the dielectric drum 1. Detected by head 24. At this time, the dielectric drum 1 is stopped.

The output signal from the optical head 24 is amplified by an amplifier 25 and then input to a failure determination circuit 26. The failure determination circuit 26 detects the operation state of the electrostatic recording head 2 based on the output of the test pattern output circuit 23, that is, the state of the test pattern formed on the dielectric drum 1, and To detect a failure.

If the electrostatic recording head 2 does not have any clogging of the openings 11, 11... And the electrostatic recording head 2 is operating normally, the linear image of each test pattern can be obtained as shown in FIG. As shown in FIG. Therefore, the output signal of the optical head 24 obtained when the linear image of the test pattern is scanned by the optical head 24, as shown in FIG. When scanning, the predetermined current value i2 is maintained, and when scanning the linear image portion of the test pattern, the current value decreases to the predetermined current value i1 or less. Therefore, the failure determination circuit 26
Is the optical head 24 obtained from all test patterns
Is monitored, and this output current is shown in FIG. 10 (a).
In the case where the electrostatic recording head 2 changes in the state shown in FIG.

However, if the openings 11, 11,... Of the electrostatic recording head 2 are completely clogged, a linear image of the test pattern is not formed as shown in FIG. 10 (b). Therefore, the linear image of the test pattern is
As shown in FIG. 10 (b), the output signal of the optical head 24 obtained when scanning is performed on the portion other than the linear image of the test pattern, as a matter of course,
Even when the linear image portion of the test pattern is scanned, the current value does not decrease from the predetermined current value i2. Therefore, the failure determination circuit 26 determines that the electrostatic recording head 2 has failed, displays the fact, and stops the operation of the electrostatic recording device. At this time, the failure determination circuit 26 can also display the information on which of the openings 11, 11,... Of the electrostatic recording head 24 does not emit ions, thereby facilitating the repair.

Next, if the openings 11, 11,... Of the electrostatic recording head 2 are partially clogged, the linear image of the test pattern is shifted to a predetermined width as shown in FIG. Is also formed with a narrow width. Therefore, when the linear image of the test pattern is scanned by the optical head 24, the output signal of the optical head 24 is obtained by scanning the linear image portion of the test pattern as shown in FIG. Even when the current is flowing, the current does not decrease to the predetermined current value i1. Therefore, the failure determination circuit 26 also determines that the electrostatic recording head 2 has failed, displays the fact, and stops the operation of the electrostatic recording device.

When an abnormal discharge occurs from the openings 11, 11,... Of the electrostatic recording head 2, the linear image of the test pattern becomes wider than a predetermined width as shown in FIG. May be formed. Therefore, the output signal of the optical head 24 obtained when the linear image of the test pattern is scanned by the optical head 24 is a portion other than the linear image of the test pattern as shown in FIG. , The position x1 where the current value should be i2
And x2, the current value drops to i1. for that reason,
The failure determination circuit 26 also determines that the electrostatic recording head 2 has failed, displays a message to that effect, and stops the operation of the electrostatic recording device.

Furthermore, if the ion emission from the openings 11, 11,... Of the electrostatic recording head 2 is not stable, a linear image of the test pattern will be displaced in this longitudinal direction as shown in FIG. A chip may occur partially along. Also in this case, similarly to the case shown in FIG. 10 (e), the output signal of the optical head 24 obtained when the linear image of the test pattern is scanned by the optical head 24 is shown in FIG. 10 (e).
As shown in (2), the current does not decrease from the predetermined current value i2 depending on the position in the longitudinal direction of the linear image of the test pattern. Therefore, the failure determination circuit 26 also determines that the electrostatic recording head 2 has failed, displays the fact, and stops the operation of the electrostatic recording device.

When ions are emitted from the openings 11, 11... Of the electrostatic recording head 2 where ions are not originally emitted, a linear image of the test pattern is formed as shown in FIG. 10 (f). However, a linear image 30-7 is recorded at a position where an image should not be originally recorded. In this case, the tenth
As shown in FIG. 10F, the output signal of the optical head 24 obtained when the linear image of the test pattern is scanned by the optical head 24 is obtained as shown in FIG.
At a position where there should be no image, the current value drops to a predetermined current value i2 or less. Therefore, the failure determination circuit 26 also determines that the electrostatic recording head 2 has failed in this case, displays the fact, and stops the operation of the electrostatic recording device. Test pattern output circuit for outputting a test pattern to the electrostatic recording head 2
23, and a failure determination circuit 26 that detects an operation state of the electrostatic recording head 2 based on an output of the test pattern output circuit 23 to detect a failure of the electrostatic recording head 2. Therefore, a test pattern is output to the electrostatic recording head 2 by the test pattern output circuit 23 at a predetermined timing, and an operation of recording an electrostatic latent image is performed by the electrostatic recording head 2. The operation state of the electrostatic recording head 2 is detected on the basis of the above, the failure of the electrostatic recording head 2 is detected by the failure determination circuit 26, and the operation of the electrostatic recording apparatus is stopped. Therefore, even if clogging or the like occurs in the openings 11, 11,... Of the screen electrode 9 in the recording head 2, it is possible to prevent a large amount of printed matter having bit defects that are not printed on the recorded image. .

At this time, the failure determination circuit 26 may include means for notifying the failure when the failure of the electrostatic recording head 2 is detected. As the notification performed by the failure determination circuit 26, a warning sound may be generated, or the failure may be displayed on the display unit of the host computer. In addition, as shown in FIG. 11, a spare electrostatic recording head 2 is prepared, and when a failure occurs in the electrostatic recording head 2, the electrostatic recording head 2 is replaced with a spare one. It may be.

In the above embodiment, the case where the optical head 24 is moved along the axial direction of the dielectric drum 1 to detect the toner image formed on the dielectric drum 1 has been described.
However, it is not limited to this.

That is, as shown in FIG.
4, 24… are used in combination, and these optical heads 24, 24…
, A plurality of images formed by the electrostatic recording head 2 can be simultaneously detected, and these optical heads 24, 24.
Is moved a plurality of times along the axial direction of the dielectric drum 1, the time required for detecting the toner image on the dielectric drum 1 can be reduced.

FIG. 13 shows a case where an elongated head capable of simultaneously detecting the toner image on the dielectric drum 1 over the entire width is used as the optical head 24. In this case, the presence / absence of ion emission from the openings 11, 11,... Of the individual electrostatic recording heads 2 cannot be detected. Therefore, as shown in FIG. 14, the total output current from the optical head 24 is detected, and if this output current value is within a predetermined width range, it is determined that the output current is normal, and otherwise, it is determined that the output current is abnormal. ing.

Note that an image sensor used for a scanner or the like of an OA device may be used instead of the optical head 24,
In this case, the optical density of all the areas on the dielectric drum 1 can be detected. In order to detect the toner image on the dielectric drum 1 using the image sensor, an image of the toner image on the dielectric drum 1 may be formed on the image sensor via a selfoc lens. ,
Alternatively, the image of the toner image on the dielectric drum 1 may be formed on an image sensor via a reduction optical system.

FIG. 15 shows another embodiment of the present invention, in which the same parts as those of the above embodiment are denoted by the same reference numerals. It is configured to detect a failure by detecting the amount of charge of ions emitted from the electrostatic recording head according to the output from the printer.

That is, when a test pattern is output from the test pattern output circuit 23, the probe 40 for detecting the amount of charge of ions is disposed below the electrostatic recording head 2 as shown in FIG. As shown in FIG. 16, the charge amount detection probe 40 includes a plurality of detection electrodes 41, 41... Divided corresponding to the control electrodes 5, 5,. , Are connected to ammeters 43, 43 via amplifiers 42, 42, respectively.

The output signal from the charge amount detection probe 40 is amplified by the amplifier 42, and then the current is detected by the ammeters 43, 43, and is input to the failure determination circuit 26.
The failure determining circuit 26 operates the electrostatic recording head 2 based on the output of the test pattern output circuit 23, that is, as shown in FIG.
Are detected as shown in FIG. 3 to detect a failure of the electrostatic recording head 2.

If the electrostatic recording head 2 has no clogging of the openings 11, 11... And the electrostatic recording head 2 is operating normally, the electrostatic latent image of the test pattern is detected by the charge amount detecting probe 40. As shown in FIG. 18A, the output signal in this case maintains a predetermined current value between the current value i2 and the current value i1 when scanning the test pattern portion. Therefore,
The failure determination circuit 26 monitors the output current of the charge amount detection probe 40 obtained from all the test patterns, and if the output current changes in the state shown in FIG. 2 is determined to be normal.

However, if the openings 11, 11,... Of the electrostatic recording head 2 are clogged, the output signal obtained when the electrostatic latent image of the test pattern is detected by the charge amount detecting probe 40 will be as shown in FIG. As shown in (b), the current value is equal to or less than a predetermined current value i1. Therefore, the failure determination circuit 26 determines that the electrostatic recording head 2 has failed, displays the fact, and stops the operation of the electrostatic recording device. At this time, the failure determination circuit 26 can also display the information on which of the openings 11, 11,... Of the electrostatic recording head 24 does not emit ions, thereby facilitating the repair.

Next, when an abnormal discharge occurs from the openings 11, 11,... Of the electrostatic recording head 2, the electrostatic latent image of the test pattern
As shown in FIG. 18 (c), the width is formed to be wider than the predetermined width, and is equal to or more than the predetermined current value i2. Therefore, the failure determination circuit 26 also determines that the electrostatic recording head 2 has failed, displays the fact, and stops the operation of the electrostatic recording device.

Further, when an abnormal discharge in which the discharge continues from the openings 11, 11,... Of the electrostatic recording head 2 occurs, the electrostatic latent image of the test pattern is changed to a current value as shown in FIG. The current value is maintained between the predetermined current value i2 and the current value i1, but the current value is maintained at the time t 'and t "where the current value must be a low value in a portion other than the latent image of the original test pattern. Therefore, the failure determination circuit 26 also determines that the electrostatic recording head 2 has failed, displays the fact, and displays the operation of the electrostatic recording apparatus. To stop.

Note that, as described above, the current waveform obtained by scanning all the drive electrodes has the openings 1-1, 1-2, 1-3, and 1 of the electrostatic recording head 2 as shown in FIG. -4 continuously appears.

Other configurations and operations are the same as those of the above-described embodiment, and the description thereof will be omitted.

In the above embodiment, the charge amount of the ion stream emitted from each of the openings 1-1, 1-2,... Of the electrostatic recording head 2 is measured using the charge amount detection probe 40 shown in FIG. The case of measuring individually has been described. However, the present invention is not limited to this. As shown in FIG. 20, the electrostatic latent image on the dielectric drum 1 is simultaneously detected over the entire width as the charge amount detecting probe 40 as shown in FIG. A possible elongated member may be used.
In this case, the opening 1-of each electrostatic recording head 2
.. Cannot be detected. Therefore, as shown in FIG. 21, the total output current from the charge amount detection probe 40 is detected, and this output current value is between the predetermined width range i5 and i6, and the minimum value is i7 or less. In the case of, normal is detected, otherwise, an abnormality is detected.

Further, in the above embodiment, the charge amount detecting probe 40 is moved below the electrostatic recording head 2 to
Is configured to detect the amount of ion emission from
Without being limited to this, as shown in FIG. 22,
The electrostatic recording head 2 may be moved onto the charge amount detecting probe 40 disposed on the side thereof.

〔The invention's effect〕

The present invention has the above configuration and operation, and even when clogging or the like occurs in an opening of a screen electrode in an electrostatic recording head, a large amount of printed matter having a bit defect that is not printed on a recorded image is generated. Thus, it is possible to provide an electrostatic recording device capable of preventing the occurrence of the problem.

Further, according to the present invention, the test pattern output from the test pattern output means may be formed in at least an adjacent one of the ion generators formed in a matrix at the intersection of the plurality of drive electrodes and the plurality of control electrodes. Since this is a test pattern that outputs a test pattern that emits an ion current independently from each ion generation unit without simultaneously discharging an ion flow from the unit, the ion flow is output independently from at least the adjacent ion generation units. By detecting the test pattern formed by discharge, when the electrostatic recording head is used, clogging or the like occurs in any of the openings of the screen electrode of the electrostatic recording head, and the test pattern is discharged from the ion generation unit. For example, when the amount of ions in the ion stream is reduced, it is possible to reliably detect this and detect a failure of the electrostatic recording head.

[Brief description of the drawings]

FIG. 1 is a structural view showing an embodiment of the electrostatic recording apparatus according to the present invention, FIG. 2 is a plan view showing an ion generating portion of the electrostatic recording head, FIG. 3 is a sectional view of the same, and FIG. FIG. 5 is a plan view showing the electrostatic recording head, FIG. 6 is a cross-sectional view showing an operation state of the electrostatic recording head, FIG. 7 is a block diagram showing a control system, and FIG. 8 is an optical head. FIG. 9 is a plan view showing a test pattern, FIGS. 10 (a) to 10 (f) are explanatory diagrams showing test pattern detection states, and FIGS. 11 (a) and 11 (b). ) Is an explanatory view showing the replacement state of the electrostatic recording head, FIG. 12 is a perspective view showing another example of the optical head, and FIGS. 13A and 13B are detection diagrams showing another example of the optical head. Explanatory diagram and perspective view of the state, FIG. 14 is a graph showing the operation of the optical head, FIG. 15 is a configuration diagram showing another embodiment of the present invention, 16 view (a), (b) is a perspective view and a cross-sectional view showing a charge amount detection probe, FIG. 17 is an explanatory view showing an opening for ion emission of the electrostatic recording head,
18 (a) to 18 (d) are graphs each showing a detection state of a test pattern, FIG. 19 is a graph showing a detection state of a test pattern, and FIGS. 20 (a) and (b) are charge amount detection probes. 21 is a perspective view and a cross-sectional view showing another embodiment, FIG. 21 is a graph showing a detection state of a test pattern, FIG. 22 is a configuration diagram showing another embodiment of the present invention, and FIG. FIG. 24 is a configuration diagram showing a recording apparatus, FIG. 24 is a plan view showing an ion generating portion of the electrostatic recording head, FIG. 25 is a cross-sectional view thereof, FIG. 26 is a plan view showing the electrostatic recording head, and FIG. FIG. 28 is a sectional view showing an operation state of the electrostatic recording head. [Explanation of Symbols] 1 ... Dielectric drum 2 ... Electrostatic recording head 23 ... Test pattern output circuit 26 ... Failure determination circuit

Continuation of the front page (72) Inventor Koga Komura 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Co., Ltd. Ebina Works (56) References JP-A-63-283960 (JP, A) JP-A-1-205192 (JP) , A) JP-A-1-121223 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41J 2/41 G03G 15/00 115

Claims (6)

(57) [Claims] 1. An ion generator formed by laminating a plurality of drive electrodes and a plurality of control electrodes on an insulating substrate in a matrix with a first insulating layer interposed therebetween, and a second electrode formed on a control electrode side of the ion generator. An electrostatic recording head having an ion flow control section composed of screen electrodes stacked and interposed via two insulating layers; an electrostatic latent image carrier for carrying an electrostatic latent image formed by the electrostatic recording head; Developing means for making an electrostatic latent image formed on the electrostatic latent image carrier noticeable, and an intersection of a plurality of drive electrodes and a plurality of control electrodes on the electrostatic recording head at a predetermined timing; A test for outputting a test pattern in which each of the ion generating units independently emits an ion current without simultaneously emitting an ion current from at least an adjacent ion generating unit among the ion generating units formed in a matrix. Pattern output An electrostatic recording apparatus, characterized by comprising: a stage, a failure detection means for detecting a failure of the electrostatic actuation state of the recording head to detect by the electrostatic recording head based on the output of the test pattern output means. 2. The electrostatic recording apparatus according to claim 1, wherein said test pattern output means outputs a test pattern for each drive electrode of the electrostatic recording head. 3. The apparatus according to claim 1, wherein said failure detecting means detects a failure by detecting a density of a developed image formed on the electrostatic latent image carrier and made conspicuous by an output from the test pattern output means. The electrostatic recording apparatus according to claim 1 or 2, wherein: 4. The apparatus according to claim 1, wherein said failure detecting means detects a failure by detecting an electric charge amount of ions emitted from the electrostatic recording head based on an output from the test pattern output means. 3. The electrostatic recording device according to claim 2. 5. The electrostatic recording according to claim 1, wherein a timing of outputting a test pattern from said test pattern output means is for every fixed number of recordings. apparatus. 6. An electrostatic recording apparatus according to claim 1, further comprising means for notifying a failure when said failure detection means detects a failure. .