JP3018469B2 - Toner jet recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner jet recording apparatus that performs recording by directly controlling a toner flow.

2. Description of the Related Art A toner jet recording apparatus is disclosed in, for example, US Pat.
This is a recording device that is reported in the specification and is a recording device including a toner crowder, an aperture electrode, and a counter electrode. The toner cloud is a means for generating a cloud of charged toner and supplying the toner cloud to the vicinity of the aperture electrode. The aperture electrode is a control unit that modulates and controls the flow of toner from the toner cloud. The aperture electrode includes a plurality of apertures, an insulating layer having openings, and a first electrode layer provided on one surface of the insulating layer. , A plurality of second electrodes provided on the other surface of the insulating layer and provided independently for each of the plurality of apertures. Further, the counter electrode is for holding a recording medium such as paper by suction, and is arranged to face the aperture electrode. In the toner jet recording apparatus configured as described above, the toner flow supplied by the toner crowder is controlled by an electric signal applied to the aperture electrode and the counter electrode, and is recorded on a recording medium such as paper.

However, when recording is performed by the toner jet recording apparatus, there is a problem that the aperture portion of the aperture electrode is clogged with toner. That is, for example, in order to obtain a recording density of 240 DPI, since the size of the dot is 100 μm at maximum, it is necessary to reduce the inner diameter of the aperture of the aperture electrode to about 50 μm at maximum. There is a problem that the toner particles accumulate on the electrode, and as a result, the aperture electrode is clogged by the toner particles, and it is difficult to always obtain a stable image output.

Accordingly, a patent application has been filed by the present applicant for a device that vibrates the aperture electrode to prevent the accumulation of toner particles. According to this method, a toner particle that is to be deposited on an aperture electrode is applied with a repulsive force larger than the above-described image force or the like that causes the deposition by the vibration acceleration generated by the vibration excited by the aperture electrode, so that the toner particle This is a method that attempts to prevent the accumulation of ash.

[Problems to be Solved by the Invention] However, as a method of exciting vibration to the aperture electrode, a method of exciting the aperture electrode by resonating itself can be easily considered. However, in general, the aperture electrode is very thin. The resonance frequency of the vibration excited in the aperture becomes very low, and it becomes difficult to give a sufficiently large vibration acceleration to the aperture electrode. As a result, it is difficult to obtain a sufficient effect of preventing the accumulation of toner particles. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to make the metal plate or the like having a thickness t.
Is attached to the elastic body by exciting an ultrasonic vibration whose resonance frequency is desirably 20 kHz or more to the elastic body. It is possible to easily excite ultrasonic vibrations to the aperture electrode, and furthermore, to sufficiently increase the vibration acceleration near the aperture to easily and effectively prevent clogging of the aperture portion, and to obtain a stable image at all times. An object of the present invention is to provide a toner jet recording apparatus capable of obtaining an output.

Means for Solving the Problems In order to achieve this object, a toner jet recording apparatus of the present invention has a plurality of openings and a control electrode for controlling charged toner passing through the openings. An aperture electrode; and excitation means provided on both ends of the arrangement of the plurality of openings on the aperture electrode, wherein each excitation means includes an elastic body and an ultrasonic vibration provided on the elastic body. A vibration mode in which the aperture electrode is excited by the excitation means has a maximum amplitude point at a portion where the plurality of openings are arranged on the aperture electrode. It is characterized by being.

Further, the toner jet recording apparatus of the present invention exhibits a higher effect by setting the resonance frequency of the ultrasonic vibration excited by the elastic body to be approximately 20 kHz or more.

[Operation] In the toner jet recording apparatus of the present invention having the above-described configuration, the vibration mode of the vibration in which the aperture electrode is excited by the excitation unit is a portion where the plurality of openings are arranged on the aperture electrode. By vibrating easily and effectively a vibration having a vibration mode having a maximum amplitude point and a vibration that can easily obtain a sufficiently large vibration acceleration in a portion where a plurality of openings are arranged, the toner Clogging of the opening can be prevented.

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

The configuration of the toner jet recording apparatus according to the present embodiment will be outlined with reference to FIG.

3, the toner jet recording apparatus 100 includes a recording unit 101 and a heat fixing unit 102. An insertion port 117 and an extraction port 118 are provided on the side of the toner jet recording apparatus 100. In the recording unit 101, an image or the like is recorded on a medium P such as plain paper entered from the insertion port 117. Then, in the heat fixing unit 102, an image or the like on the medium is fixed. Further, the medium P is sent to the outlet 118 via the guide 115.

The recording unit 101 includes a rotatable brush roller 103, the aperture electrode 1, and a counter electrode 112. Around the brush roller 103, a supply roller 104 and a scraping member 110 that are rotatable according to the rotation direction of the brush roller 103 are provided in contact with the brush roller 103, respectively. The supply roller 104 includes a supply blade 111.
Are provided in contact with each other. The toner T is stored on the supply blade 111. Then, the toner T is forcibly supplied to the supply roller 104 by the supply blade 111. Supply roller 104 and supply blade
111 is covered by the case K.

The aperture electrode 1 is provided above the brush roller 103.

In FIG. 1, the aperture electrode 1 has a number of apertures 11, an insulating layer 106, a reference electrode layer 107, a number of control electrode layers 108, and a bending vibration shown in FIG. And an exciting device 2 for exciting. The apertures 11 are provided in the insulating layer 106 in the vicinity of the center of the aperture electrode 1 in the Z direction and are provided in the insulating layer 106, and are arranged in a line in the X direction to form an aperture row 12. Further, the reference electrode layer 107 is provided on the brush layer 103 side of the insulating layer 106. Further, the control electrode layer 108 includes the insulating layer 1
06 is provided independently around the aperture 11 on the upper surface. The reference electrode layer 107 is connected to ground, and the control electrode layers 108 are connected to a number of signal sources S (not shown). Further, the excitation device 2 is attached to the insulating layer 106 by means such as adhesion.

The excitation device 2 has a rectangular elastic body 21 having a length L, a width W, and a thickness t, and is mounted on the elastic body 21 to excite the bending vibration shown in FIG. And a piezoelectric element 22 to be used. The piezoelectric element 22 mounted on the elastic body is electrically connected to a drive circuit (not shown). In the vibration shown in FIG. 2, if the vibration of the elastic body 21 is considered to be the vibration of a free-end vibrator, its resonance frequency fr
Is expressed as fr = (πλt / 2L ² ) × [{E / {12 (1-ν ² ) ρ}] ^1/2 . In this equation, E is Young's modulus, ρ is density, ν is Poisson's ratio, and λ is a constant determined by the order of the vibration mode. For example, in the vibration shown in FIG. 2, λ = 3.
5 An aperture electrode 1 is attached to the vibration device 2. The aperture t is such that the thickness t 'of the aperture electrode and the thickness t of the elastic body 21 satisfy the relationship of t >>t'. Since the electrode 1 and the elastic body 21 are configured, the resonance frequency fr of the elastic body 21 calculated by the above equation substantially matches the resonance frequency of the vibration mode shown in FIG. Here, if, for example, duralumin is selected as the material of the elastic body 21, the material constant in duralumin is E = 6.85 × 10 ¹⁰ [N / m ² ], the density is ρ = 2695 [kg / m ³ ]. When the Poisson's ratio is calculated as ν = 0.3, fr = 2.396 × 10 ³ × λt / L ² .

Further, the dimensions of the elastic body 21 are selected so that the thickness t satisfies the relationship of t >> t 'with the thickness t' of the aperture electrode 1 as described above.
And the thickness t, the resonance frequency calculated from the above equation is approximately 20
Selected to be in kilohertz or more.

That is, for example, in order to make the resonance frequency of the elastic body 21 approximately 30 kilohertz, the length L may be 50 mm, the width W may be 10 mm, and the thickness t may be 9 mm.

With the aperture electrode 1 interposed, the brush roller 10
On the opposite side of 3, the counter electrode 112 is provided with a specific space from the aperture electrode 1. The medium P that has entered this space from the insertion opening 117 and has been sent via the guide 115 and the pair of auxiliary rollers 116 passes therethrough. This counter electrode 112 is connected to a power supply E2 (minus (-)). By this voltage application, the toner T passing through the aperture 11 of the aperture electrode 1 is moved and adsorbed on the medium P.

The heat fixing unit 102 includes a heat roller 113 having a heat source and a press roller 114. The heat roller 113 and the press roller 114 are arranged so that the medium P can pass between them.

Next, the operation of the toner jet recording apparatus will be described with reference to FIG. Medium P inserted from insertion port 117
Is transported to the recording unit 101. In the recording unit 101, the toner T is pressed against the supply roller 104 by the supply blade 111 and is carried. The toner T is supplied to the brush roller 103 by the supply roller 104.
Supplied to At this time, the toner T is supplied to the supply roller 104,
In addition, it is rubbed while being in contact with the brush roller 103, and is, for example, positively (+) charged. The toner T charged to plus (+) is carried on the brush roller 103.

The brush roller 103 is scraped by the scraping member 110 near the aperture electrode 1. When the brush returns to its original state due to elasticity, the toner T carried by the brush in an appropriate amount jumps up. As a result, the toner T is supplied to the aperture electrode 1 in the form of a cloud.

Then, the flow of the toner T is modulated by the voltage applied from the signal source S to the control electrode layer 108 of the aperture electrode 1.

At this time, when an electric signal having a frequency fr [kHz] is applied from a drive circuit (not shown) to the piezoelectric element 22 attached to the aperture electrode 1, the bending vibration shown in FIG. The action of this vibration will be described later in detail. At this time, even if the charged toner particles try to adhere to the vicinity of the aperture row 12 due to the image force or the like, a large vibration acceleration due to the vibration is generated at the position of the aperture row 12 near the antinode of the vibration. Because it cannot be attached. As a result, the toner flow is always stably modulated by the signal source S and recorded on the medium P.

The positive (+) charged toner T modulated by the negative (−) power supply E2 connected to the counter electrode flies toward the counter electrode. The toner T is used as a guide
It is sucked by the medium P guided to the pair of auxiliary rollers 116 and 115.

Thereafter, the medium P is transported to the heat fixing unit 102. Then, at this location, the image on the medium P is
The image is fixed by being pressed by the press roller 113 and the press roller 114. Since this fixing method is a general method, a detailed description is omitted. Finally, the medium P on which the image has been formed passes through the guide 115 and is taken out of the outlet 1.
Transported to 18 and removed.

Next, the action of the vibration of the aperture electrode 1 configured as described above will be described in more detail with reference to FIGS. When an electric signal of a predetermined frequency fr [kHz] is applied to the piezoelectric element 22 from a drive circuit (not shown), the aperture electrode 1 has a zero-order in the X direction as shown in FIG.
A third-order bending vibration is excited. This vibration is a bending vibration in which the positions indicated by AA ′, BB ′ and CC ′ in FIG. 2 are the vibrations indicating the positions of the abdomen of the bending vibration. It is provided in the vicinity of the position BB ′. Aperture electrode 1 thus configured
Since the aperture 11 is provided in the vicinity of the abdomen BB ′ of the vibration, that is, in the vicinity of the position where the maximum vibration acceleration is obtained, the toner does not adhere to the vicinity of the aperture 11 of the aperture electrode 1, As a result, clogging of the aperture 11 can be prevented.

In this embodiment, the vibration excited in the aperture electrode has been described by taking the bending vibration shown in FIG. 2 as an example. However, the vibration is not limited to this vibration, and the vicinity of the aperture row is the antinode of the vibration. The same effect can be obtained with a vibration having a vibration mode.

Further, in the present embodiment, a piezoelectric element is used as an excitation device that excites vibration in the aperture electrode.However, the present invention is not limited to this, and other elements that can convert electric energy into mechanical energy, for example, an electrostrictive element, A magnetostrictive element or the like may be used.

Furthermore, in the present embodiment, duralumin is exemplified as the material of the elastic body, but the material is not limited to this, and other materials such as brass, metals such as stainless steel, and nonmetals such as ceramics may be used. . Furthermore, the dimensions and the resonance frequency of the elastic body are not limited to the values exemplified in this embodiment.

Various other modifications are possible without departing from the spirit of the present invention.

[Effects of the Invention] As is apparent from the above description, according to the toner jet recording apparatus of the present invention, the vibration mode of the vibration in which the aperture electrode is excited by the excitation means has a plurality of openings on the aperture electrode. Is a vibration mode in which the amplitude maximum point is located in the portion where is arranged, so that it is easy and effective to excite the ultrasonic vibration to the aperture electrode in order to prevent the charged toner from depositing on the aperture electrode. It becomes possible.

[Brief description of the drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a perspective view showing the structure of an aperture electrode, and FIG. 2 is a vibration mode of bending vibration excited by the aperture electrode. FIG. 3 is an explanatory view showing a schematic configuration of a toner jet recording apparatus using the aperture electrodes shown in FIG. In the figure, 1 is an aperture electrode, 2 is an exciting device, 21 is an elastic body, 22 is a piezoelectric element as an exciting body, and 100 is a toner jet recording device.

Continuation of front page (56) References JP-A-4-53974 (JP, A) JP-A-3-57658 (JP, A) JP-A-58-10771 (JP, A) JP-A-4-80053 (JP, A) JP-A-61-174560 (JP, A) JP-A-4-34451 (JP, A) JP-A-57-70451 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B41J 2/385

Claims (1)

(57) [Claims] An aperture electrode having a plurality of openings, a control electrode for controlling charged toner passing through the openings, and two ends of an arrangement of the plurality of openings on the aperture electrodes. Provided, wherein each of the excitation means includes an elastic body and an excitation body for exciting ultrasonic vibration provided on the elastic body, and the aperture electrode is excited by the excitation means. The toner jet recording apparatus according to claim 1, wherein a vibration mode of the vibration is a vibration mode having a maximum amplitude point in a portion where the plurality of openings are arranged on the aperture electrode.