JPH0890826A - Image forming apparatus - Google Patents

Abstract

PURPOSE: To enable a wide drawing by using a plurality of small-sized recording units in an image forming apparatus for forming an image on an image recording medium by flying toner. CONSTITUTION: Five recording units 10a-10e are arranged in a zigzag manner in the lateral direction of an image recording medium 20, and back electrode rollers 22a-22e are disposed by providing gaps of 1mm at the position opposed to an aperture electrode 1 on the units 10a-10e. The medium 20 is inserted to be conveyed to the gap of 1m. Toner image is formed on the medium 20 by the five units 10a-10e, and fixed on the medium 10 by a fixing roller 26.

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 in copying machines, printers, plotters, facsimiles and the like.

[0002]

2. Description of the Related Art Conventionally, as one of image forming apparatuses, toner particles pass through an aperture by applying a drive signal based on an image signal to an aperture electrode body having a plurality of small holes (hereinafter referred to as apertures). An image forming apparatus which obtains an image on an image recording medium such as a printing paper by controlling and passing the toner particles is disclosed in JP-A-6-155798.

In such an image forming apparatus, as shown in FIG. 8, the toner carrying roller 114 and the image recording medium 120 are opposed to each other with the aperture electrode body 101 interposed therebetween.
A rear electrode roller 122 is provided on the rear surface of the image recording medium 120. In addition, the image forming apparatus 100
As shown in FIG. 9, the aperture electrode body 101 used in step 1 is formed by forming a 25 μm-thick polyimide insulating sheet 102 in a rectangular shape and disposing it in parallel with the toner carrying roller 114. Further, this aperture electrode body 101 is shown in FIG.
As shown in an enlarged view of FIG. 0, a plurality of apertures 106, which are holes having a diameter of 100 μm, are formed in a line in the longitudinal direction of the aperture electrode body 101, and a copper foil having a thickness of 1 μm and a width of 20 μm is provided around the aperture 106. Control electrode 104 consisting of
Are formed respectively. Further, a conducting wire 105 is connected to the control electrode 104, and the conducting wire 105 is an IC for switching a control voltage to the control electrode 104 as shown in FIG.
Each is connected to the chip 103. This conductor 10
5 is an extremely fine wiring, for example, 200 DPI
In the case of the image forming apparatus 100 corresponding to the image recording medium of A4 width at the resolution of 1,600 or more are wired.

Further, as shown in FIGS. 8 and 9, the aperture electrode 1 is provided below the aperture electrode body 101.
A toner carrying roller 114 for supplying the toner 116 to the aperture 106 of 01 is provided in parallel with the aperture electrode body 101 with a length substantially the same as the length of the aperture electrode body 101, and on the lower left of the toner carrying roller 114, A toner supply roller 112 for supporting the toner 116 on the toner carrying roller 114 is provided, and a toner layer regulation for making the toner 116 carried on the toner carrying roller 114 into a uniform layer and uniformly charging the toner is provided above the toner supply roller 112. Blade 11
8 are provided.

[0005]

However, the aperture electrode body of the image forming apparatus described above has a large number of extremely fine conductive wires formed on an insulating sheet having a thickness of only 25 μm, and also corresponds to the number of pixels. Since it is necessary to make holes for a large number of apertures and to connect the IC chips to the conductor wires for mounting a large number of IC chips, it has been difficult to manufacture them. In particular, when it is used for a plotter or the like, it is necessary to form a continuous aperture electrode body having a drawing width of 1 m, for example. In this case, at a resolution of 200 DPI, it is necessary to form approximately 8000 apertures and control electrodes and to mount an IC chip that controls these control electrodes, and it is not possible to provide an aperture electrode body without defects in such a large number of mechanisms. It was very difficult, and the yield of finished products of aperture electrode bodies was very poor.

Further, it is difficult to manufacture the toner carrying roller, which is an important part, while keeping the tolerances related to drawing such as runout and cylindricity. Especially, the wide and long ones have the required tolerances. It was very expensive to manufacture in consideration.

Further, regarding the toner layer regulating blade,
It was difficult to make the length longer with accuracy.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an image forming apparatus capable of drawing a wide image by using a plurality of small toner flying control means.

[0009]

In order to achieve this object, an image forming apparatus according to a first aspect of the invention has an image recording medium on which an image is recorded by the flight of toner according to an image signal, and the flight of the toner. In order to control, a plurality of toner fly control means dividedly arranged in the width direction of the image recording medium orthogonal to the conveying direction of the image record medium, and a toner supply means for supplying toner to the toner fly control means. I have it.

Further, in the image forming apparatus according to the invention of claim 2, the toner supply unit is divided into a plurality in the width direction of the image recording medium which is orthogonal to the conveying direction of the image recording medium. I am trying.

Further, the image forming and toner flying control means of the invention of claim 3 is characterized in that a plurality of openings are formed and each opening is an electrode array having a control electrode.

[0012]

In the image forming apparatus of the present invention having the above structure, the toner is supplied to the toner flying control means by the toner supply means, and the toner is supplied in the width direction of the image recording medium orthogonal to the conveying direction of the image recording medium. Each of the toner flight control means, which is provided in a divided manner and is provided in plurality, controls the flight of the toner onto the image recording medium according to the image signal. Here, since a plurality of toner flight control means are divided and arranged in the width direction of the image recording medium orthogonal to the conveyance direction of the image recording medium, one toner flight control means has a width equal to the width of the image recording medium. Since a small unit having a size of a fraction of one is sufficient, each member of the image recording medium can be easily and accurately produced. Therefore, wide drawing can be performed by using a small unit which has a low manufacturing cost and a good recording quality.

In the image forming apparatus according to the second aspect of the present invention, a plurality of toner supplying means for supplying toner to the toner flying control means are also divided and arranged in the width direction of the image recording medium orthogonal to the conveying direction of the image recording medium. Therefore, one toner supply unit may be a fraction of the width of the image recording medium. Therefore, by using a toner supply means that is inexpensive and has a high yield,
Wide drawing is possible.

In the image forming apparatus according to the third aspect of the present invention, since a plurality of openings are formed and the flight of the toner onto the image recording medium is controlled by the electrode array in which each opening has a control electrode, it is simple. With an electrode array of various configurations,
Wide drawing is possible.

[0015]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the structure of an image forming apparatus according to an embodiment of the present invention.

The image forming apparatus 50 includes five recording units 10a, 10b, 10c and 10 as shown in FIG.
d and 10e are provided on the lower side of the image recording medium 20, and the recording units 10a, 10b, 10c, 10d and 10e are provided.
Are not shown in a so-called zigzag arrangement in the width direction of the image recording medium 20 (hereinafter referred to as the “width direction of the image recording medium 20”) orthogonal to the conveying direction of the image recording medium 20 (the direction of arrow A in FIG. 1). It is fixed to the body frame. That is, the three recording units 10a, 10b, 10c are arranged in a row at a constant interval in the width direction of the image recording medium 20, and the gaps between the recording units 10a and 10b are closed with respect to the gap. The recording unit 10d is arranged on the downstream side in the transport direction of the image recording medium 20 (direction of arrow A shown in FIG. 1). Also, the recording unit 10b
The recording unit 10e is arranged similarly to the recording unit 10d so as to close the gap between the recording unit 10c and the recording unit 10c. That is, the recording unit 10d and the recording unit 10e
Are arranged in a line in the width direction of the image recording medium 20, and are arranged in parallel with the recording units 10a, 10b, 10c.

A back electrode roller 22a is axially supported on a body frame (not shown) at a position facing the aperture electrode body 1 of the recording unit 10a with the image recording medium 20 interposed therebetween. Further, the rear electrode roller 22b is provided at a position facing the aperture electrode body 1 of the recording unit 10b.
However, the back electrode roller 22c is located at a position facing the aperture electrode body 1 of the recording unit 10c, the back electrode roller 22d is located at a position facing the aperture electrode body 1 of the recording unit 10d, and the aperture electrode body of the recording unit 10e. 1, a back electrode roller 22e is pivotally supported on a main body frame (not shown) at a position facing 1 in the same manner as the back electrode roller 22a. Further, each of the back electrode rollers 22a to 22e is configured to be driven by the stepping motor 23 shown in FIG.

The above-mentioned back electrode rollers 22a to 22e,
A gap of 1 mm is provided from the aperture electrode body 1 provided in each of the recording units 10a to 10e.
The image recording medium 20 can be inserted and conveyed in the space of m.

Further, the recording units 10a to 10e.
On the other hand, on the downstream side in the transport direction of the image recording medium 20, the image recording medium 20 is formed by the recording units 10a to 10e.
A fixing roller 26 and a driven roller 27 for fixing the image formed by the toner formed above are pivotally supported by a body frame (not shown). The fixing roller 26 is a heat roller having a built-in electric heater, and fixes the toner image on the image recording medium 20 by heating.
The toner image is not limited to the heat roller and may be fixed by pressure.

Next, the structure of the recording units 10a to 10e will be described with reference to FIGS.

FIG. 3 is a front view showing the structure of the image forming apparatus 50 of this embodiment.

Since all the recording units 10a to 10e have the same structure, the structure of the recording unit 10a shown in FIG. 3 will be described as a representative. The recording unit 10a is provided with a toner case 11 which also serves as a housing. The toner 16 is stored in the right side portion of the toner case 11, and the upper surface of the toner case 11 is connected to the image recording medium 20. An aperture electrode body 1 having an aperture 6 which is a large number of holes is provided so as to face each other.

In this aperture electrode body 1, as shown in FIG. 4, a plurality of apertures 6 which are holes having a diameter of about 100 μm are formed in a row on an insulating sheet 2 made of polyimide having a thickness of 25 μm, and on the upper surface thereof. A control electrode 4 having a thickness of 1 μm is formed around each aperture 6. Then, as shown in FIG. 3, the aperture electrode body 1 includes an image recording medium 20.
With the control electrode 4 facing the side, the toner case 11
Is disposed on the upper surface of.

Next, the internal structure of the recording unit 10 will be described with reference to FIG.

Below the aperture electrode body 1 provided on the upper surface of the toner case 11 of the recording unit 10, a toner carrying roller 14 for supplying the toner 16 to the aperture electrode body 1 is provided. The toner case 11 is axially supported along the longitudinal direction and is driven by the step motor 15 shown in FIG. The toner carrying roller 14 is made of aluminum and has a cylindrical shape, and a large number of very fine irregularities are formed on the surface thereof, so that the toner 16 is easily carried.

A toner supply roller 12 for supplying the toner 16 to the toner carrying roller 14 is provided in parallel to the toner carrying roller 14 so as to contact the toner carrying roller 14 at the lower right of the toner carrying roller 14. It is pivotally supported.

Further, in the vicinity of the toner carrying roller 14 above the toner supply roller 12, the toner 16 carried on the toner carrying roller 14 is regulated into a uniform layer on the roller surface of the toner carrying roller 14, and A toner layer regulating blade 18 that evenly charges the toner 16 is provided. The toner layer regulating blade 18 is fixed to the toner case 11 by pressing one end of the toner layer regulating blade 18 against the toner carrying roller 14.

Next, the positional relationship between the aperture 6 of the aperture electrode body 1 and the toner carrying roller 14 provided on the recording unit 10a will be described in detail. As shown in FIG. 5, each aperture 6 has an aperture. The center line 30 of the toner carrying roller 1 and the uppermost part of the peripheral surface of the toner carrying roller 14
It is arranged so as to pass through on a straight line connecting the central axis 32 of No. 4 of FIG. As a result, the aperture 6 uniformly contacts the toner carrying roller 14 at the uppermost part of the toner carrying roller 14 and passes through the lower surface of each aperture 6 of the toner carrying roller 1.
It is possible to make the distribution of the toner 16 carried on the toner 4 uniform throughout the entire area of the aperture 6. Further, since the wall surface of the aperture 6 and the flying direction of the toner 16 are parallel to each other, the toner can be stably jetted.

Further, the aperture electrode body 1 itself, as shown in FIG.
It is pressed so that it bends slightly to the left and right with the center at. As a result, the contact area between the aperture electrode body 1 and the toner carrying roller 14 can be increased, and the lower periphery of the aperture 6 can be pressed uniformly to the left and right, so that the toner is carried to the aperture 6 by the toner carrying roller 14. It is possible to suppress the occurrence of uneven density of the toner 16 as much as possible.

Next, the control circuit of the image forming apparatus 50 will be described with reference to FIG.

The image forming apparatus 50 receives and stores an image signal transmitted from an external computer, a communication line or the like, and also transmits the image signal to a central control circuit 28 described later, which is an image signal receiving circuit 29. Is provided.
The image signal receiving circuit 29 is connected to the central control circuit 28. The central control circuit 28 includes a well-known CPU, a ROM for recording control programs and the like, and a RAM for storing various data such as image signals, and controls the entire image forming apparatus 50. . To the central control circuit 28, a toner carrying roller drive circuit 31 for controlling the drive of the toner carrying roller 14 is connected,
A step motor 15 for driving the toner carrying roller 14 is connected to the toner carrying roller drive circuit 31.

Further, the central control circuit 28 is connected to a control voltage application circuit 8 for controlling application of a control voltage to each control electrode 4 provided on the aperture electrode body 1, and the control voltage application circuit 8 is connected. The control electrode 4 is connected to. The control voltage application circuit 8 is configured to apply 0 V and +50 V to the control electrode 4 based on the image signal. However, the control voltage applied to the control electrode is not limited to 0 V and +50 V described above, and may be, for example, -30 V.
And + 50V, -30V and + 30V, 0V and +30
Any negative voltage such as V, 0V and + 20V or a combination of a voltage of 0V and a positive voltage may be used.

Further, the central control circuit 28 is connected to a DC power source 24 for applying a voltage of +1 kV to the back electrode rollers 22a to 22e. Back electrode rollers 22a to 22e are connected to the DC power supply 24.
The toner carrying roller 14 is connected to the ground side of the image forming apparatus 50, and each of the above voltages is a voltage for the ground side.

The central control circuit 28 is connected to a back electrode roller drive circuit 33 for controlling the step motor 23 for driving the back electrode roller 22, and the back electrode roller drive circuit 33 is connected to the step motor 23. Are connected.

Each of the recording units 10a to 10e described above
1 are arranged in the width direction of the image recording medium 20 in a zigzag arrangement as shown in FIG. 1 with some of them overlapping each other. Therefore, each aperture electrode body 1 provided in each recording unit 10a to 10e is arranged. As shown in FIG. 6, the rows of the apertures 6 are arranged without a break in the width direction of the image recording medium 20, and it is possible to draw without a break in the width direction of the image recording medium 20. Become.

Next, the image forming operation of the image forming apparatus 50 configured as described above will be described with reference to FIGS.

First, when an image signal from an external device (not shown) is transmitted to the image signal receiving circuit 29, it is temporarily stored in the image signal receiving circuit 29, and then from the image signal receiving circuit 29 to the central control circuit 28. The image signal is transmitted. Then, the central control circuit 28 sends a signal for instructing the driving of the step motor 15 to the toner carrying roller drive circuit 31.

Next, a step pulse is transmitted from the toner carrying roller drive circuit 31 to the step motor 15,
The step motor 15 rotates, and the toner carrying roller 14 of each recording unit 10 rotates in the direction of arrow B shown in FIG. At the same time, the toner supply roller 12 is also driven in the direction of arrow C by a motor (not shown), and the toner 16 stored in the toner case 11 is rubbed against the toner carrying roller 14 by the rotation of the toner supply roller 12, and a minus It is charged on the toner carrying roller 14 and carried on the toner carrying roller 14. The carried toner 16 is the toner carrying roller 1
By rotating 4 in the direction of arrow B, the toner layer regulating blade 18 comes into contact with the toner layer regulating blade 18 and is pressed by the toner layer regulating blade 18 against the toner carrying roller 14 to be thinned and charged. Then, the toner carrying roller 14
By the rotation in the direction of arrow B, the sheet is conveyed toward the aperture 6 of the aperture electrode body 1. Then, the toner 16 on the toner carrying roller 14 is supplied below the aperture 6 while being rubbed by the insulating member 2 of the aperture electrode body 1.

Further, at this time, the central control circuit 28 divides the image signal transmitted from the image signal receiving circuit 29 into the signals for respective portions where the five recording units 10a to 10e record. Next, among the recording units 10a to 10e arranged in a staggered manner, three recording units 10a, 1 located on the upstream side in the transport direction of the image recording medium 20.
The image signal of the portion in which 0b and 10c draw first is transmitted to the control voltage application circuit 8 and the image recording medium 20 to the three recording units 10a, 10b and 10c.
Of the recording units 10d, 10 located on the downstream side in the transport direction of the
The image signal of the portion drawn by e is once stored in the central control circuit 28.
It is stored in a RAM (not shown).

Then, a control voltage of +50 V is applied from the control voltage application circuit 8 to the control electrode 4 on the aperture electrode body 1 of the three recording units 10a, 10b, 10c. As a result, an electric force line from the control electrode 4 toward the toner carrying roller 14 is formed in the vicinity of the aperture 6 corresponding to the image portion due to the potential difference between the control electrode 4 and the toner carrying roller 14. As a result, the negatively charged toner receives an electrostatic force in the direction of higher electric potential, passes through the aperture 6 from the toner carrying roller 14, and is drawn out to the control electrode 4 side. The toner 16 pulled out is further applied to the image recording medium 2 by the voltage applied to the back electrode 22.
By the electric field formed between 0 and the aperture electrode body 1,
The image recording medium 20 flies toward the image recording medium 20.
Deposit on top to form pixels.

A voltage of 0V is applied from the control voltage application circuit 8 to the control electrode 4 of the aperture electrode body 1 of each recording unit 10 corresponding to the non-image portion. As a result, since no electric field is formed between the toner carrying roller 14 and the control electrode 4, the toner 16 on the toner carrying roller 14 does not receive the electrostatic force and therefore does not pass through the aperture 6.

At this time, the three recording units 10
With respect to the two recording units arranged on the downstream side in the transport direction of the image recording medium 20 with respect to a, 10b, and 10c, the drawing operation is not yet performed.

Here, the three recording units 10a,
When one line of pixels is formed on the image recording medium 20 by the drawing operation of 10b and 10c, the central control circuit 28 sends a signal to the back electrode roller drive circuit 33, and the back electrode roller drive circuit 33 sends the signal to the step motor 23. A step signal is transmitted, the step motor 23 rotates, the back electrode rollers 22a to 22e rotate in the direction of arrow D shown in FIG. 3, and the image recording medium 20 is fed in the direction of arrow A by one line.
Then, by repeating the above-mentioned image forming process, pixels are formed line by line.

Next, the pixel portion of one line formed at the beginning is the three recording units 10a, 10
When it is sent up to the line connecting the rows of the apertures 6 on the recording units 10d and 10e arranged on the downstream side of the sheet conveyance direction with respect to b and 10c, it is stored in the RAM of the central control circuit 28. Recording units 10d and 10e
The image signal for drawing is transmitted to the control voltage applying circuit 8. Then, a control voltage is applied from the control voltage application circuit 8 to each control electrode 4 on the aperture electrode bodies 1 of the recording units 10d and 10e, and one line of pixels is formed by the toner 16 that has passed through the aperture 6. Therefore, here, for the first time, complete recording of one line of pixels is completed over the entire width direction of the image recording medium 20.

Thereafter, the central control circuit 28 sends a signal to the back electrode roller drive circuit 33, and a step signal is sent from the back electrode roller drive circuit 33 to the step motor 23.
The step motor 23 rotates to rotate the back electrode rollers 22a to 2a.
2e is rotated in the direction of arrow D shown in FIG. 3, and the image recording medium 20 is fed by one line in the direction of arrow A. After that, the recording unit 10a, 10b, 10c causes the portion of the pixel formed on the second line to be the recording unit 1
When sent to the line connecting the rows of apertures 6 on 0d and 10e, the recording units 10d and 10e stored in the RAM of the central control circuit 28 are in charge of drawing 2.
The image signal for the line is transmitted to the control voltage application circuit 8 and the toner 16 that has passed through each aperture 6 in the same manner as described above forms a pixel for one line. Thereafter, a similar image forming process is repeated to form a toner image on the entire surface of the image recording medium 20. After that, the formed toner image is fixed on the image recording medium 20 by the fixing device 26.

As described above in detail, in the image forming apparatus of this embodiment, the formation of the pixels in the width direction of the image recording medium 20 is performed.
Since it can be performed by the five recording units 10a to 10e arranged in a divided manner, the aperture electrode body 1, the toner carrying roller 14, and the toner supply roller 12 having a length sufficient to cover the width of the image recording medium 20. It is not necessary to manufacture the toner layer regulation blade 18 and the wide width image can be drawn by using the aperture electrode body 1 having a short length, the toner carrying roller 14 and the like. Therefore, the aperture electrode body 1, the toner carrying roller 14 and the like need only have a short length, are easy to manufacture, and improve the yield of finished products. Therefore, an image forming apparatus capable of wide drawing can be manufactured at low cost.

Further, by combining a plurality of recording units as in this embodiment to form one image forming apparatus, it is possible to make the manufacturing extremely easy.

Further, since the divided recording units are miniaturized, the manufacturing apparatus having a small moving stroke can be used in flowing the manufacturing line, so that the accuracy can be improved and the yield can be improved.

In the completed image forming apparatus, even if one of the recording units is defective and cannot be repaired,
The function of the image forming apparatus can be easily restored by replacing only one of the recording units.

The present invention is not limited to the embodiments described in detail above, and various modifications can be made without departing from the spirit of the invention.

In the above embodiment, the units are arranged in a staggered arrangement, but they may be arranged in a slanted manner in one direction as shown in FIG. 7, for example.

Further, in the above embodiment, the control voltage of the aperture corresponding to the non-image portion is set to 0V, but this may be a negative voltage. In this case, an image with less fogging can be obtained. Further, in the above embodiment, the aperture electrode body is used as the toner flow control means, but it is also possible to use, for example, a knitted electrode body as described in the specification of US Pat. No. 5,036,341.

[0054]

As is apparent from the above description, since the image forming apparatus of the present invention is composed of the recording units divided in the width direction, it is possible to perform wide drawing by using a small recording unit. Therefore, each member of the recording unit can be easily and accurately created. Therefore,
It is possible to provide an image forming apparatus having a high yield, a low manufacturing cost, and a good recording quality.

Further, even when the recording unit of the image forming apparatus fails, only the relevant unit needs to be replaced, so that repair can be performed easily and at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing the configuration of an image forming apparatus that is an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a control device of the image forming apparatus according to the present exemplary embodiment.

FIG. 3 is a front view of the image forming apparatus according to the present exemplary embodiment.

FIG. 4 is a perspective view showing a configuration of an aperture electrode body used in the image forming apparatus of this embodiment.

FIG. 5 is a diagram showing a positional relationship between an aperture electrode body and a toner carrying roller used in the image forming apparatus of this embodiment.

FIG. 6 is a plan view showing the arrangement of aperture electrode bodies used in the image forming apparatus of this embodiment.

FIG. 7 is a plan view showing an arrangement of aperture electrode bodies of an image forming apparatus according to another embodiment of the present invention.

FIG. 8 is a front view showing a configuration of a conventional image forming apparatus.

FIG. 9 is a plan view of an aperture electrode body used in a conventional image forming apparatus.

FIG. 10 is an enlarged view around an aperture of an aperture electrode body used in a conventional image forming apparatus.

[Explanation of symbols]

 1 Aperture electrode body 2 Insulating sheet 4 Control electrode 6 Aperture 8 Control voltage application circuit 10a Recording unit 10b Recording unit 10c Recording unit 10d Recording unit 10e Recording unit 11 Toner case 12 Toner supply roller 14 Toner carrying roller 16 Toner 22a Rear electrode roller 22b Rear electrode roller 22c Rear electrode roller 22d Rear electrode roller 22e Rear electrode roller 24 DC power supply

Claims (3)

[Claims] 1. An image recording medium on which an image is recorded by the flight of toner according to an image signal, and a width of the image recording medium orthogonal to the transport direction of the image recording medium for controlling the flight of the toner. An image forming apparatus comprising: a plurality of toner flight control means arranged in a divided manner in a direction; and a toner supply means for supplying toner to the toner flight control means. 2. The toner supply unit is divided into a plurality in a width direction of the image recording medium which is orthogonal to a conveying direction of the image recording medium.
The image forming apparatus according to item 1. 3. The toner flying control means is an electrode array in which a plurality of openings are formed and each opening has a control electrode.
The image forming apparatus according to item 1.