JPH10329353A - Image-forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of shortcircuiting and discharging, by dividing a plurality of control electrodes of a charge body control means to a plurality of groups, and arranging on an insulating substrate so that the same voltage can be impressed to adjacent control electrodes of different groups. SOLUTION: A copper foil pattern of leading wire parts 3 and control electrodes 4 formed on an insulating sheet of an aperture electrode body are formed in a TAB tape formation process. Although joint parts 28 are periodically generated at exposure groups in a longitudinal direction of a TAB tape at this time, the control electrodes 4 adjacent to each other via the joint 28 are connected mutually at a position of the leading wire part 3. A pitch of the joints of a divided exposure is dependent on a feed accuracy. However, even when the leading wire parts 3 and control electrodes 4 of adjacent exposure groups are formed with low fed accuracy, the same voltage is impressed to the adjacent electrodes via the joint 28, thereby preventing discharging because of a shortcircuit of adjacent electrodes at the part. Stable printing is hence enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus which can be used for a copying machine, a printer, a plotter, a facsimile, and the like.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus that controls the passage of toner particles through an aperture by applying an image signal to an electrode having an aperture (opening) to obtain an image on a support is disclosed in U.S. Pat. No. 689,935.

The image forming apparatus described in US Pat. No. 3,689,935 has a shield electrode continuous on one side with an insulator layer interposed therebetween, and a plurality of shield electrodes insulated from each other on the other side. An aperture electrode body having an aperture that is a through-hole formed at least in a row corresponding to each of the plurality of control electrodes that are insulated from the control electrode; and the control electrode and the shield electrode. Means for selectively applying a voltage between the aperture electrode body, means for supplying charged toner particles to the aperture of the aperture electrode body, and a high voltage which is disposed on the opposite side of the aperture electrode body with the support therebetween. And a means for moving the support relative to the aperture electrode body to position the support in the particle flow path.

However, according to the image forming apparatus having the above-described structure, the recording quality is deteriorated due to the clogging of the aperture with the toner particles, and the recording speed cannot be increased too much.

[0005] The present applicant has further studied, and
Japanese Patent Laid-Open No. 155798 proposes an image forming apparatus capable of greatly improving recording characteristics by arranging a carrier holding a toner and an aperture electrode body in contact with each other. According to this image forming apparatus, the aperture is not clogged, the image quality is remarkably improved, and the size and cost of the image forming apparatus can be reduced.

[0006]

Here, the aperture electrode body having the above-mentioned structure is formed on a TAB tape substrate provided with fine wiring of control electrodes made of copper foil on a polyimide insulating substrate.
Drive elements such as C are connected to TAB (Tape Automat
In a process called "ed bonding", the fine wiring is mounted on one end of the fine wiring, and an opening is formed near the other end by a method such as laser processing. Hereinafter, the above-mentioned T which is an intermediate product in the above-mentioned manufacturing process and a constituent element of the aperture electrode body will be described.
The AB tape substrate will be described with reference to a plan view of FIG. 6 and an enlarged view of a main part of FIG.

[0007] The TAB tape substrate is a sprocket 7
By performing lithography for each of several tens of millimeter square frames (exposure groups) on the polyimide tape with a long copper foil of 20 m or more provided with the above, by melting the copper foil of the non-wiring pattern portion by etching, The conductive portion 3 and the control electrode 4 in the form of the fine wiring are formed.

In the lithography process, as described above, since pattern exposure corresponding to the pattern of the conductive wire portion 3 and the control electrode 4 is performed for every several tens of mm square, it is inevitable at the boundary of each frame. Consequently, a seam 28 as shown in FIG. 7 is generated.

In the lithography process, it is very difficult to make the pitch Ph of the conductor 3 and the control electrode 4 over both sides of the joint 28 equal to the pitch Pk of the other portions. If the dimensional tolerance between Pk and Pk is strict, the yield will be reduced and the manufacturing cost will increase. On the other hand, when the dimensional tolerance is loosened, the joint 28
When a different voltage is applied to the control electrode 4 adjacent to this portion when the pitch Ph in the area becomes narrow, a short circuit occurs due to discharge, and the applied voltage to the control electrode 4 is controlled by an overcurrent at the time of the discharge. There has been a problem in that a driving element such as an IC is destroyed or the aperture electrode itself is broken by heat generated during the discharge. Further, when the pitch Ph between the adjacent control electrodes at the joint 28 is widened to prevent discharge, the electric field intensity distribution in the aperture of the portion changes, and an appropriate contrast may not be obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide an image forming apparatus having excellent image quality and easy to manufacture.

[0011]

In order to achieve this object, an image forming apparatus according to a first aspect of the present invention is provided with a charged member passing portion, and is provided in the vicinity of the charged member passing portion. Charged body control means having a large number of control electrodes to which a predetermined voltage is applied in order to form an electric field for controlling the passage of the charged body in the charged body passing section in the charged body passing section,
A charged body supply means for supplying a charged body to the charged body control means, and the charged body supply means includes a back electrode provided on the opposite side of the charged body control means, and is provided by the charged body supply means. Controlling the passage of the supplied charged body in the charged body control unit, and forming an image by flying the charged body onto a support positioned on the side of the back electrode, wherein the charged body control means On the insulating substrate, the large number of control electrodes are divided into a plurality of groups, arranged and formed, and the same voltage can be applied to adjacent control electrodes belonging to different groups in adjacent portions of each group. It is characterized by:

Therefore, since different voltages are not applied between the two control electrodes belonging to different groups and adjacent to each other, the above-mentioned two voltages are not applied due to the fluctuation of the adjacent pitch.
Even if the two control electrodes are very close to each other, no short circuit or discharge occurs, and the charged body control means is not damaged.

According to a second aspect of the present invention, in the image forming apparatus, the charged body control means is configured by connecting adjacent control electrodes belonging to different groups at adjacent portions of the respective groups by conducting wires. I have.

That is, two control electrodes belonging to different groups and adjacent to each other are always electrically connected to each other by the conducting wire, so that the same voltage is always applied. Therefore, even if the adjacent pitch fluctuates, trouble such as discharge does not occur, and highly reliable image formation is guaranteed.

According to a third aspect of the present invention, in the image forming apparatus, the charged body control means connects adjacent control electrodes belonging to different groups in adjacent portions of each group to the same output terminal of the same drive element. It is characterized by having been constituted.

That is, two control electrodes belonging to different groups and adjacent to each other are electrically connected to each other by being connected to the same output terminal of the same drive element, so that the same voltage is always applied. Will be. Therefore, even if the adjacent pitch fluctuates, trouble such as discharge does not occur, and highly reliable image formation is guaranteed.

According to a fourth aspect of the present invention, in the image forming apparatus, the charged body control means transmits the same image data to adjacent control electrodes belonging to different groups in adjacent portions of each group. It is characterized by having comprised.

That is, since the same image data is always transmitted to two control electrodes belonging to different groups and adjacent to each other, the same voltage is always applied. Therefore, even if the adjacent pitch fluctuates, trouble such as discharge does not occur, and highly reliable image formation is guaranteed.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus according to the present embodiment.

Aperture electrode body 1 as charged body control means
On the upper side, a columnar back electrode roller 22 as a back electrode is disposed rotatably with respect to a main body frame (not shown) of the image forming apparatus, with a gap of about 1 mm. Is configured to be able to be transported in a direction indicated by an arrow in FIG.

A toner supply device 10 is provided below the aperture electrode body 1, and the support body 20 is connected to the aperture electrode body 1 and the back electrode roller 22 on the carry-in side of the support body 20. A transport roller 29 for transporting the sheet between them is rotatably disposed, and a fixing device 26 is disposed in the forward direction of the support 20 transported by the back electrode roller 22, and is supported by the main body frame. Is done.

Next, the details of each component will be described.

The toner supply device 10 includes a toner case 11 also serving as a housing,
It is composed of a toner 16 housed therein, a supply roller 12, a toner carrying roller 14, and a toner layer regulating blade 18.

The toner carrying roller 14 carries the toner 16 as a charged body in a layer on the surface thereof and transports the toner 16 toward the aperture electrode body 1. The supply roller 12 is provided with the toner carrying roller. The toner 16 is supplied to the surface 14.

The supply roller 12 and the toner carrying roller 14 are supported in the toner case 11 so as to be rotatable in the direction shown by the arrow, and are arranged so that they are in contact with each other. The toner layer regulating blade 18 is for adjusting the amount of the toner 16 carried on the toner carrying roller 14 to be uniform on the roller surface and for uniformly charging the toner 16. , Is pressed against the toner carrying roller 14.

As shown in FIG. 2 and FIG. 3, the aperture electrode body 1 has a rectangular opening formed in a 25 μm-thick polyimide insulation sheet 2 penetrating the insulation sheet 2. A large number of apertures 6 as passage portions are arranged in a line at equal intervals, and two of the peripheral edges of the apertures of the apertures 6 on the upper surface side of the insulating sheet 2 are opposed to each other.
The control electrode 4 and the conductor 3 for controlling an electric field formed in the aperture 6 are formed of copper foil having a thickness of 8 μm so as to face the side. A plurality of drive ICs 5 for applying a predetermined voltage to the electrodes 4 are arranged. Then, the aperture electrode body 1 having the above-described structure is, as shown in FIG.
In a state where the control electrode 4 is opposed to the control electrode 4, the control electrode 4 is disposed in contact with the toner 16 on the toner carrying roller 14 at the aperture position of the insulating sheet 2.

The copper foil patterns of the conductor 3 and the control electrode 4 formed on the insulating sheet 2 in the aperture electrode body 1 are formed by the above-described TAB tape manufacturing process. At this time, the joint 28 of the exposure group is
It occurs periodically in the longitudinal direction of the B tape.

FIG. 3 is an enlarged view of the vicinity of the control electrode 4. The control electrode 4 is provided so as to be in close contact with the left and right sides of the aperture 6 in FIG. The control electrode 4 has a drive I
C5 is formed integrally with the conductive wire portion 3 on which is mounted. As shown in the figure, in the case of a resolution of 300 DPi, the aperture 6 has a line width of the control electrode 4 of 0.02 μm and a pitch of 0.085 μm.

FIG. 4 shows an enlarged portion corresponding to the joint 28 in FIG. The control electrodes 4 adjacent to each other across the joint 28 are connected to each other at the position of the conductive wire portion 3 so that the same voltage is applied. Specifically, as a mask pattern used for the divisional exposure of the lithography, a pattern corresponding to both ends of the array of the conductive wire portions 3 is configured to increase the line width to the outside, respectively. Since the portions where the line widths are widened overlap each other between the adjacent exposure groups, the conductive portions 3 adjacent to each other across the joint 28 and the exposure mask therebetween overlap by the subsequent etching. The portion becomes the remaining portion of the copper foil pattern, and a wiring pattern as shown in FIG. 4 is obtained.

In FIG. 4, the control electrodes 4 adjacent to each other with the joint 28 interposed therebetween are configured so that the same voltage can be applied by integrating the conductive wire portion 3. May be configured to always have the same potential, and the configuration is not limited to the configuration in FIG.

The control voltage application circuit 8 transmits an image data signal to the drive IC 5 connected to the control electrode 4 of the aperture electrode body 1 based on image data from an image data input unit (not shown). And the driving IC 5
Is +40 V (ON voltage) or −20 V to the control electrode 4 according to the image data signal (ON / OFF of dot formation by the toner 16) from the control voltage application circuit 8.
V (OFF voltage) can be selectively applied.

The back electrode roller 22 is arranged to face the toner carrying roller 14 via the aperture 6 of the aperture electrode body 1. As described above, the back electrode roller 22 is disposed with a gap of about 1 mm from the aperture electrode body 1, and is rotatably supported by a main body frame (not shown). A DC power supply 24 is connected to the back electrode roller 22, and the DC power supply 24 is configured to be able to apply a high voltage of +1 kV to the back electrode roller 22.

The support 20 is transported by a pair of transport rollers 2.
9, the back electrode roller 22, and the fixing device 26. Support 20 inserted from insertion opening (not shown)
Are transported to the fixing device 26 through the gap between the back electrode roller 22 and the aperture electrode body 1 which are image forming positions. Fixing device 2
Reference numeral 6 includes a heat roller having a heat source therein and a pressure roller pressed against the heat roller. The support 20 on which the image is formed is sandwiched between the heat roller and the pressure roller in the fixing device 26, and after the toner image is heat-fixed, is discharged from a discharge port (not shown) to the outside of the image forming apparatus.

Next, the operation of the image forming apparatus configured as described above will be described.

When an image forming command is input from an external device (not shown) to an image data input unit (not shown) of the image forming apparatus, first, the toner carrying roller 14 and the supply roller 12
Starts rotating in the direction of the arrow shown in FIG.

The toner 16 conveyed by the surface of the supply roller 12 is rubbed against the surface of the toner carrying roller 14 to be negatively charged and carried on the surface of the toner carrying roller 14 by the toner layer regulating blade. 18
After being uniformly thinned and charged substantially uniformly, the toner is transported toward the aperture electrode body 1 by the rotation of the toner carrying roller 14 and rubbed by the insulating sheet 2 of the aperture electrode body 1 under the aperture 6. Supplied to

On the other hand, the support 20 is transported between the aperture electrode body 1 and the back electrode roller 22 while being sandwiched by the transport rollers 29.

Here, based on the image data, the control electrode 4
Is applied with a predetermined voltage. An ON voltage (+40 V) is applied to a portion where a print dot is formed, and an OFF voltage (−20 V) is applied to a portion where a print dot is not formed. Applied under the control of IC5.

When an ON voltage (+40 V) is applied to the control electrode 4, the potential difference between the control electrode 4 and the toner carrying roller 14 causes the toner carrying roller 1 to move from the control electrode 4.
4 are formed. As a result, the negatively charged toner 16 receives an electrostatic force in the direction of higher potential, passes through the aperture 6 from above the toner carrying roller 14, and is drawn out to the control electrode 4 side. Pulled out toner 16
Is + 1k applied to the back electrode roller 22
By the electric field formed between the support 20 and the aperture electrode body 1 by the voltage of V, it flies toward the support 20. As a result, the toner 1 flying toward the support 20
6 are deposited on the support 20 to form pixels.

The OFF voltage (−20) is applied to the control electrode 4.
When V) is applied, electric lines of force from the toner carrying roller 14 to the control electrode 4 are formed. as a result,
The negatively charged toner receives an electrostatic force in a direction pressed against the carrying roller 14 and does not pass through the aperture.

The support 20 is conveyed by one pixel in the direction perpendicular to the aperture row by the support conveying unit 40 while one line of pixels is formed by the toner 16 on the surface. Then, by repeating this process, a toner image representing a desired image is formed on the entire surface of the support 20. After that, the formed toner image is fixed on the support 20 by the fixing device 26. Finally, the support 20 on which the toner image has been formed is discharged out of the image forming apparatus from a discharge port (not shown).

According to the image forming apparatus of the present embodiment described above, the following effects unique to the present invention can be obtained.

When the aperture electrode body is formed on the basis of the TAB tape substrate manufactured by lithography based on the divided exposure, the pitch at which the divided exposure is connected depends on the feeding accuracy of the long polyimide tape with copper foil. In general, the feed accuracy is determined by a clearance between a sprocket formed at both ends of the TAB tape and a transport mechanism that transports the TAB tape so as to mesh with the sprocket.
Due to fluctuations in the feed speed of the motor etc. that drives the transport
It tends to be quite low.

However, according to the image forming apparatus of the above-described embodiment, even if the lead portions and the control electrodes of the adjacent exposure groups are formed due to the above-described low feeding accuracy, the conductive portions and the control electrodes adjacent to each other with the seam interposed therebetween are formed. Since the same voltage is applied to each other, a discharge due to a short circuit between adjacent electrodes in this portion does not occur, and stable printing can be always performed. That is, even if the connection accuracy is low in production, the problem does not occur in actual printing, and there are many contributions in production.

By applying the same voltage to adjacent control electrodes, two dots are formed in the main scanning direction (control electrode arrangement direction) for the same data. The dot diameter is about 80 microns, and there is no problem in both character output and image output in consideration of human visual recognition ability.

The present invention is not limited to the embodiment described in detail above, and various changes can be made without departing from the gist of the present invention.

In the above embodiment, the potentials of both control voltages are made the same by connecting the conductors of the control electrodes adjacent to each other with the joint therebetween. However, it is also possible to select such that the same voltage is applied to the adjacent control electrodes when mounting them on the drive IC, without using the same conductor portion or control electrode. FIG. 5 shows a mounting state on the driving IC in this case.

In FIG. 5, the driving IC 5 is provided with a plurality of output pads 9 for selecting and outputting a voltage.
Normally, the output pad 9 and the conductive wire portion 3 are wire-bonded one-to-one with gold or aluminum wire. For the conductor 3 adjacent to the joint 28,
By hitting the wire twice from the same output pad 9, the same voltage can be applied. This makes it possible to apply the same voltage without changing the shape of the adjacent conductor portion 3 in particular, thereby contributing to the reliability of printing.

In the above-described embodiment, the same voltage is applied by changing the configuration of the so-called aperture electrode body, but it may be realized by a print control method. That is, the image data may be created in advance so that the same voltage is always applied to the control electrodes adjacent to each other across the joint. According to this method, stable printing can be performed without particularly changing the head portion.

In the present embodiment, the so-called toner, which is a dry powder, has been described. However, the present invention can be applied to any printing material for a charged body. For example, a good effect is exerted on a liquid developing material such as a liquid toner and a charged ink.

Furthermore, in the present embodiment, a so-called monochromatic unit has been described, but it is obvious that the present invention can be applied to a color machine or the like in which a plurality of units are arranged.

[0053]

As is clear from the above description,
According to the image forming apparatus of the first aspect of the present invention, when a large number of control electrodes are divided into a plurality of groups, an image is formed at an adjacent portion of each group, for example, at a joint portion at the time of divided exposure by lithography. Since no discharge or short circuit occurs due to the application of the voltage corresponding to the signal, there is no problem that the driving element such as an IC or the charged body control means itself is destroyed. Therefore, it is possible to provide an image forming apparatus having excellent image quality and easy to manufacture.

According to the image forming apparatus of the second aspect,
Since the charged body control means is formed by connecting adjacent control electrodes belonging to different groups in the adjacent portion of each group with a conductive wire, the same voltage is always applied to the adjacent control electrodes in the adjacent portion. You. Therefore, even if the adjacent pitch of the control electrodes fluctuates, trouble such as discharge does not occur, and reliable image formation is guaranteed.

According to the image forming apparatus of the third aspect,
Since the charged body control means is configured by connecting adjacent control electrodes belonging to different groups in the adjacent part of each group to the same output terminal of the same drive element, the charged body control means is connected to the adjacent control electrode in the adjacent part. On the other hand, the same voltage is always applied. Therefore, even if the adjacent pitch of the control electrodes fluctuates, trouble such as discharge does not occur, and reliable image formation is guaranteed.

According to the image forming apparatus of the fourth aspect,
Since the charged body control means is configured to transmit the same image data to adjacent control electrodes belonging to different groups in an adjacent portion of each group,
The same voltage is always applied to adjacent control electrodes in the adjacent portion. Therefore, even if the adjacent pitch of the control electrodes fluctuates, trouble such as discharge does not occur, and reliable image formation is guaranteed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment of the invention.

FIG. 2 is a perspective view illustrating a configuration of an aperture electrode body used in the image forming apparatus.

FIG. 3 is an enlarged plan view of the vicinity of an aperture in the aperture electrode body.

FIG. 4 is an enlarged plan view of a main part of the aperture electrode body.

FIG. 5 is an enlarged plan view of a main part of an aperture electrode body in an image forming apparatus according to another embodiment of the present invention.

FIG. 6 is a plan view showing an entire configuration of the aperture electrode body.

FIG. 7 is an enlarged plan view of a main part of a conventional aperture electrode body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Aperture electrode body 3 Conductor part 4 Control electrode 6 Aperture 14 Toner carrying roller 28 Joint

Claims (4)

[Claims] An electric field is provided in the vicinity of the charged body passing section and the charged body passing section, and an electric field for controlling the passage of the charged body in the charged body passing section is formed in the charged body passing section. Charged body control means having a number of control electrodes to which a predetermined voltage is applied, charged body supply means for supplying a charged body to the charged body control means, and the charged body supply means sandwiching the charged body control means And a back electrode provided on the opposite side to control the passage of the charged body supplied by the charged body supply means in the charged body control unit, and the charged body is provided on the support positioned on the side of the back electrode. In the image forming apparatus for forming an image by flying the plurality of control electrodes, the charged body control means divides the plurality of control electrodes into a plurality of groups on an insulating substrate and forms an array. An image forming apparatus characterized in that applied configured to be able to same voltage to the control electrode adjacent belonging to the group that. 2. The image forming apparatus according to claim 1, wherein said charged body control means is configured by connecting adjacent control electrodes belonging to different groups in adjacent portions of each of said groups with a conductive wire. apparatus. 3. The charged body control means is characterized in that adjacent control electrodes belonging to different groups are connected to the same output terminal of the same drive element in the adjacent portion of each group. The image forming apparatus according to claim 1. 4. The apparatus according to claim 1, wherein said charged body control means transmits the same image data to adjacent control electrodes belonging to different groups in an adjacent portion of each group. The image forming apparatus as described in the above.