JPH0642185U - Image recorder - Google Patents

Abstract

(57) [Abstract] [Purpose] The amount of controllable toner flow is increased, and the rise and break of the toner flow is improved to increase the density and contrast of the image area, and to prevent non-images due to tailing. (EN) Provided is an image recording device capable of preventing stains on a line portion and obtaining a high quality image. [Structure] The toner push-out device 19 includes a push-out member 1.
8, a support member 17 that guides the pushing member 18, and a driving device 16 that controls the driving of the pushing member 18. The toner push-out device 19 is provided with an opening 2 for adjusting the toner flow in the opening 2 of the aperture plate 1.
By arranging it immediately below, the flow of the toner T passing through the opening 2 is controlled.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an image recording device that can be used in copiers, printers, plotters, facsimiles and the like.

[0002]

[Prior art]

 Conventionally, an image recording apparatus for controlling the passage of toner particles through an opening by applying an image signal to an electrode of an aperture electrode plate and recording an image on an image receptor is disclosed in US Pat. No. 3,689,935 and the drawings. Proposed. This image recording device is composed of a reference electrode that is continuous on one side with an insulating layer sandwiched between it and a plurality of control electrodes that are insulated from each other on the other side. Aperture electrode plate having at least one row of openings through the layer, means for selectively applying a potential between the control and reference electrodes, and supplying charged particles near the openings And means for moving the image receptor and the aperture electrode plate relatively to position the image receptor in the particle flow path.

[0003]

[Problems to be solved by the device]

 However, it is difficult to control the toner that passes through the opening of the aperture electrode plate with an electric signal, and the toner may drop out without passing through the image area (ON, the position where the toner passes through the opening). The toner passes through the non-image area (OFF, the position where the toner does not pass through the opening), causing fog.

Further, when ON, the toner passes through the opening because only the toner existing in the vicinity of the opening is sucked up by the electric field leaking to the toner feeder side of the reference electrode. The density of the image area was low.

Further, when the electrodes are turned on and off, there is a time lag when the toner flow passes through the opening, the rise and break of the toner flow are poor, and the image becomes unsightly due to dropout or tailing.

The present invention has been made in order to solve the above-mentioned problems, and by increasing the controllable amount of toner flow and improving the rise and break of the toner flow, An object of the present invention is to provide an image recording apparatus capable of obtaining a high-quality image by increasing the density and contrast, preventing stains on non-image areas due to tailing and the like.

[0007]

[Means for Solving the Problems]

 In order to achieve this object, an image recording apparatus of the present invention comprises an aperture plate having a plurality of openings, a toner cloud forming means for forming a toner cloud, and a counter electrode provided opposite to the aperture plate. And a toner pushing-out means for pushing out the toner of the toner cloud in the direction of the opening.

[0008]

[Action]

 According to the image recording apparatus of the present invention having the above structure, the toner cloud forming means forms the toner cloud, and the toner pushing means pushes the toner of the toner cloud toward the opening of the aperture plate. Due to the wind pressure at this time, the toner enters the inside of the opening, and the toner is further propelled toward the counter electrode to form an image on the image receptor provided between the counter electrode and the aperture plate.

[0009]

【Example】

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of the image recording apparatus of this embodiment.

First, the structure of the apparatus will be described. A side portion of the apparatus exterior 25 is provided with an insertion port 23 for inserting the image receiving body P and an outlet 24 for taking out the image receiving body P to the outside. There is. A recording unit 21 and a fixing unit 22 are provided inside the apparatus.

In the recording unit 21, an aperture electrode 1, a toner case 14 provided near the aperture electrode 1 for storing the toner T, and a toner T passing through the opening 2 of the aperture plate 1 are provided. And a counter electrode 6 for attracting to the image receptor P. Inside the toner case 14, a brush roller 11 formed of an insulator and rotatably provided, and a toner pushing device 19 are provided, and a scraping member 12 is provided upstream of the brush roller 11 in the direction of the arrow. , And a supply roller 13 are provided. Further, a charge removal brush 26 is provided in contact with the brush roller 11 downstream of the brush roller 11 in the direction of the arrow. The static elimination brush 26 is grounded. A layer thickness regulating member 15 is provided close to the supply roller 13.

As shown in FIG. 2, the aperture plate 1 is composed of an insulating layer 3, a ground electrode 4, and a large number of openings 2. The openings 2 are opened through the insulating layer 3 and the ground electrode 4 and arranged in a line. The base portion (insulating layer) of the aperture plate 1 is made of an insulator (resin or the like) in this embodiment, but it may be made of metal, resin, ceramic or the like. Give.

A piezoelectric element 9 is provided at the end of the aperture plate 1. The piezoelectric element 9 is deformed by an oscillating voltage applied from the oscillator 8 so that the aperture plate 1 vibrates. Here, a vibration frequency that causes the aperture plate 1 to resonate is selected. When the aperture plate 1 is resonated, its amplitude is maximized, and a vibration amplitude several thousand times that obtained when the aperture plate 1 is not resonated is obtained. Generally, the aperture plate 1 is designed so that the resonance frequency is a value of 20 kilohertz or more. Vibrations with a frequency of 20 kilohertz do not cause noise because they are beyond the audible range of humans.

The toner push-out device 19 is basically considered to be an impact head used in an impact printer.

FIG. 5 shows a schematic configuration diagram of an example of such an impact head. A yoke 43, an armature 41, and an elastic body 47 are installed on the support 46. A core ball 45 is installed on the yoke 43, and a coil 44 is wound around the core ball 45. The coil 44 is connected to the image signal voltage applying means S. A print wire 42 is installed at the tip of the armature 41, and the print wire 42 is supported by a supporting member 57 at the tip portion.

The operation of this impact head will be described. When the image signal voltage (image area) is applied to the coil 44 wound around the core ball 45 by the image signal voltage applying means S, the armature 41 is attracted to the core ball 45 by the magnetic force (arrow 49). direction). As a result, the print wire 42 projects. In the non-image area, the print wire 42 returns in the direction of the arrow 50 and is stored in the support member 57.

The toner push-out device 19 is shown in FIGS. 3 and 4. FIG. 3 shows the state when the image data is in the image area (ON), and FIG. 4 shows the state when the image data is in the non-image area (OFF).

The toner push-out device 19 controls the drive of the push-out member 18 (corresponding to the print wire 42 of the impact head), the support member 17 for guiding the push-out member 18, and the push-out member 18 (the same armature 41). , The yoke 43, the coil 44, the core ball 45, the support 46, and the elastic body 47). The drive device 16 drives and controls the push member 18 to be pushed outward (see FIG. 3) and stored in the support member 17 (see FIG. 4). The pushing member 18 is grounded, and the driving device 16 is connected to the image signal voltage applying means S. The toner push-out devices 19 are installed in the same number as the openings 2 so that the push-out members 18 are arranged immediately below the openings 2 of the aperture plate 1.

In this embodiment, the pushing member 18 has a length of about 1 mm protruding from the supporting member 17, and the average particle diameter of the toner is 10 μm. The distance from the tip to the opening 2 was set to about 1.2 mm. Normally, the distance from the tip of the pushing member 18 stored in the supporting member 17 to the opening 2 is larger than the average particle size of the toner T used and the length of the pushing member 18 protruding from the supporting member 17. Take big. For example, in the present embodiment, when a toner having an average particle diameter of 10 μm is used, this distance must be larger than 10 μm and the length of the pushing member 18 protruding from the supporting member 17 must be larger than 1 mm (1000 μm). I won't. Therefore, since it is 1000 μm or more, it is set to 1100 μm, for example. Further, the area of the tip of the pushing member 18 may be larger or smaller than the area of the opening 2. The diameter was set to 200 μm.

The counter electrode 6 is connected to a power source V, and a voltage having a polarity opposite to the charging polarity of the toner T that has passed through the opening 2 of the aperture plate 1 is applied (minus (−) in this embodiment). Is).

The image receptor P is inserted from the insertion port 23, guided to the guide 33 and the pair of guide rollers 34, and is adsorbed and held by the counter electrode 6. Then, at this place, the toner T is adsorbed onto the image receiving body P. Further, the image receptor P is configured to be peeled off from the counter electrode 6 after passing through the recording unit 21, sent to the fixing unit 22, and then taken out from the take-out port 24.

The fixing unit 22 includes a heat roller 31 and a press roller 32. These rollers are arranged so as to face each other, the image receiving body P passes between them, and is thermally fixed by the heat of the heat roller 31.

Next, the operation will be described.

In the recording unit 21, the toner T is carried on the supply roller 13, and the layer thickness regulating member 15 forms a uniform toner layer on the supply roller 13. Then, a uniform amount of toner T is supplied to the brush roller 11. At this time, the toner T is rubbed while being in contact with the supply roller 13 and the brush roller 11, and is charged positively, for example. Then, the positively charged toner T is carried on the brush roller 11.

Then, the brush of the brush roller 11 is scratched by the scraping member 12 in the vicinity of the aperture plate 1. Therefore, due to elasticity, when the brush returns to its original position, the toner T carried by the brush in an appropriate amount jumps up. The toner T that has jumped up is moved by the wind force of the brush of the brush roller 11, and is supplied to the upper portion of the toner pushing device 19.

Then, the supplied cloud of the toner T is modulated by the toner pushing device 19 just below the opening 2 of the aperture plate 1. That is, when the image data is applied to the image line portion (ON) by the image signal voltage applying means S, the pushing member 18 in the toner pushing device 19 is driven by the driving device 16 to project toward the opening 2. The toner T enters the inside of the opening 2 due to the wind pressure at this time, and the toner T passes through the opening 2 by the electric field formed between the ground electrode 4 and the pushing member 18 and the counter electrode 6, and the counter electrode Fly in 6 directions. Further, at the position where the image data is in the non-image area (OF F), since the pushing member 18 is stored, the toner cloud does not pass through the opening 2.

At this time, a part of the toner T that does not pass through the opening 2 tries to adhere to the aperture plate 1 due to an image force or the like, but the aperture plate 1 vibrates due to the vibration by the piezoelectric element 9. Further, even if the toner T adheres, it is removed by sieving. The vibration frequency at this time is, for example, 30 kilohertz.

The toner cloud that has not been used for recording passes through the upper portion of the toner pushing-out device 19, is then discharged by the discharging brush 26, and is collected again in the toner case 14. Further, the brush roller 11 carrying the toner T which has not been flipped up by the scraping member 12 further rotates and is discharged by the charge removing brush 26, and at the same time, the carried toner T is collected again in the toner case 14. .

On the other hand, the image receptor P inserted from the insertion port 23 is adsorbed to the counter electrode 6 via the guide 33 and the pair of guide rollers 34. Then, the image receiving body P is conveyed to the upper part of the recording unit 21. At this position, the positively charged toner T which has been modulated by the toner pushing device 19 and has passed through the opening 2 is generated by the electric field formed between the ground electrode 4 and the pushing member 18 and the counter electrode 6 by the power source V. The image receptor P is adsorbed in flight.

The image receiving body P with the toner T attached thereto is separated from the counter electrode 6 and is conveyed to the fixing unit 22. Then, the toner T on the image receiving body P is thermally fixed by the fixing unit 22. Since this heat fixing method is a known technique, detailed description thereof will be omitted.

The image receptor P that has passed through the fixing unit 22 is conveyed to the take-out port 24 via the guide 33, and taken out from there.

As is apparent from the above description, in the image recording apparatus of this embodiment, the toner pushing device 19 pushes the toner T of the toner cloud toward the opening 2 of the aperture plate 1, and the wind pressure at this time causes The toner T enters the inside of the opening 2, and the toner T flies toward the counter electrode 6 to form an image on the image receiving body P. This allows more toner particles to be controlled at one time than in the conventional toner flow that is controlled by the electric field formed by the electrodes of the aperture electrode plate, resulting in better rise and breakage of the toner flow. Become. As a result, an image with high density and high contrast can be obtained.

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

For example, the toner pushing-out device is not necessarily required to have the number of apertures of the aperture electrode, and a method of moving the head having one to several tens of pushing-out members along the row of the apertures to modulate the toner flow is also available. is there. In this case, since it is not necessary to provide the push-out member for the toner push-out device by the number of the openings 2, the device can be further reduced in weight, simplified, and reduced in cost.

There is also a method of applying a voltage having the same polarity as the charging polarity of the toner to the pushing member. In this case, the electric field formed between the pushing member 18 and the counter electrode 6 facilitates the modulation of the toner flow.

In the toner pushing-out device, for example, a vibration control member applying a piezoelectric element or the like may be used as the pushing-out member.

Further, a toner pushing device can be used as an assist device for toner flow modulation by the aperture electrode plate of the prior art.

In these cases, the conventional technique can be used almost as it is, and more toner flow can be controlled accurately.

Finally, as the aperture plate, the reference electrode (earth electrode) of the aperture electrode plate of the prior art may be abolished and only the control electrode may be used as the aperture plate. In this case, since an ON / OFF electric field is formed between the control electrode and the pushing member 18, a larger amount of toner flow can be reliably controlled.

[0040]

[Effect of device]

 As is clear from the above description, in the image recording apparatus of the present invention, the toner cloud forming means forms the toner cloud, and the toner pushing means pushes the toner of the toner cloud toward the opening of the aperture plate. Due to the wind pressure at this time, the toner enters the inside of the opening, and the toner is further ejected toward the counter electrode to form an image on the image receptor provided between the counter electrode and the aperture plate. As a result, many toner particles can be controlled at once as compared with the conventional toner flow controlled by the electric field formed by the electrode of the aperture electrode plate, and the rise and break of the toner flow are improved. As a result, an image with high density and high contrast can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an image recording apparatus of this embodiment.

FIG. 2 is an enlarged perspective view showing an aperture plate.

FIG. 3 is an enlarged plan view of the toner pushing-out device with a pushing-out member protruding.

FIG. 4 is an enlarged plan view of the toner pushing-out device in a state where the pushing-out member is stored.

FIG. 5 is an enlarged sectional view of an impact head.

[Explanation of symbols]

 T toner P image receptor 1 aperture plate 2 opening 6 counter electrode 11 brush roller 12 scraping member 19 toner pushing device

Claims (1)

[Scope of utility model registration request] 1. An aperture plate having a plurality of openings, a toner cloud forming means for forming a toner cloud, and a counter electrode provided so as to face the aperture plate,
Passing the toner of the toner cloud through the opening,
In an image recording apparatus configured to further fly in the direction of the counter electrode and form an image with the toner on an image receiving body provided between the counter electrode and the aperture plate, the toner of the toner cloud is opened in the opening portion. An image recording apparatus comprising a toner pushing-out unit that pushes out in a direction.