JP3013422B2 - 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 suitable for use in a copying machine, a printer, and the like.

[Related Art] Conventionally, a toner jet recording apparatus used for a copying machine, a printer, and the like has a well-known toner crowder, an aperture electrode, and a counter electrode.

The toner cloud is a toner supply unit that generates a cloud of charged toner and supplies the toner cloud to the vicinity of the aperture electrode.

The aperture electrode is a control unit for modulating the toner flow from the toner crowder, and includes an insulating layer having a large number of apertures, a first electrode layer, and a large number of second electrodes.

The first electrode layer is provided on the toner layer side of the insulating layer.

The second electrode layer is provided independently around the aperture on the opposite side of the insulating layer from the first electrode layer.

The counter electrode mounts and holds printing paper or the like, and is arranged to face the aperture electrode.

The first electrode layer of the aperture electrode is grounded, and the second electrode layer is connected to each signal source. Further, a toner flying voltage (a voltage having a polarity opposite to the charging polarity of the toner, for example, a minus (−electrode voltage) when plus (+) charged toner is used) is applied to the opposite electrode.

[Problems to be Solved by the Invention] However, in the above-described conventional toner jet recording apparatus, the first electrode layer of the aperture electrode is grounded, and the two electrode layers are connected to respective signal sources. . Further, a toner flying voltage, that is, a voltage having a polarity opposite to the charged polarity of the toner, for example, plus (+) is applied to the opposite electrode.
When a charged toner is used, a negative (-) polarity voltage is applied. In this case, there is a disadvantage that it is difficult to form a print image having a desired high density contrast on the print output.

The present invention has been made in view of the above, and an object of the present invention is to provide an excellent toner jet recording apparatus capable of forming a high-contrast print image with high density on a print output by increasing a supply amount of toner to a print medium. Is to do.

[Means for Solving the Problems] In order to solve the above problems, a toner jet recording apparatus of the present invention includes a toner supply unit for supplying a charged toner, and a first toner supply unit provided on the toner supply unit side. An electrode layer, an insulating layer having an opening formed therein, and an aperture electrode for modulating the charged toner by sequentially disposing the second electrode layer; and the charged toner so that the charged toner flies in the direction of the first electrode layer. And a power source for applying a constant bias voltage having a polarity opposite to the charging polarity to the first electrode layer.

[Operation] In the toner jet recording apparatus of the present invention configured as described above, a constant bias voltage having a polarity opposite to the toner charging polarity such that the charged toner flies in this direction is applied to the first electrode layer. As a result, the supply amount of the toner increases with respect to the print medium, whereby a print image having a high density contrast can be formed on the print output.

Next, an embodiment of a toner jet recording apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a configuration diagram showing an embodiment, FIG. 2 is a perspective view showing a configuration of an aperture electrode, and FIG. 3 is a diagram showing a density contrast ratio of a print output with respect to a toner flying voltage.

In FIG. 1, reference numeral 10 denotes a toner jet recording device, which includes a recording unit 12, a heat fixing unit 14, and an insertion port provided on a side portion.
18 and an outlet 20 are provided.

In the recording unit 12, an image is formed on a print medium P such as plain paper inserted through the insertion port 18, and the image on the print medium P is fixed by the heat fixing unit 14. Subsequently, the print medium P
Is led out of the outlet 20 by the guide 24.

The recording unit 12 includes a rotating brush roller 30, an aperture electrode 32 and a rotating counter electrode 34. Around the brush roller 30, a supply roller 36 is arranged in the rotation direction.
And a layer thickness regulating member 38 and a scraping member 40 are provided in contact with the brush roller 30, respectively. The brush roller 30 is grounded, the supply roller 36 is covered by a toner case K, and the toner T is stored inside the toner case K.

 FIG. 2 shows the aperture electrode 32.

Aperture electrode 32 disposed above brush roller 30
Is composed of a number of apertures 44, an insulating layer 46, and a first electrode layer 48.
And a number of second electrode layers 50. Aperture
44 is provided as an opening in the insulating layer 46, and is arranged as an example. Further, the first electrode layer 48 is formed of the brush roller 30 of the insulating layer 46.
It is provided on the side.

The second electrode layer 50 is provided independently on the upper surface of the insulating layer 46 around the aperture 44.

The first electrode layer 48 is connected to a negative (-) DC power source E1, and a number of second electrode layers 50 are connected to a signal source S which is image data.
It is connected to the.

On the opposite side of the brush roller 30 with the aperture electrode 32 interposed therebetween, a counter electrode 34 is provided at a predetermined interval from the aperture electrode 32.

The print medium P inserted through the insertion port 18 and introduced via the guide 24 and the pair of auxiliary rollers 56 passes through the space. This counter electrode 34 is connected to a DC power supply E2 (minus (-)). By applying the voltage from the DC power supply E2, the toner T passing through the aperture 44 of the aperture electrode 32 is moved and absorbed by the print medium P.

The heat fixing unit 14 includes a heat roller 60 as a heat source and a press roller 58, and is arranged at an interval through which the print medium P passes.

 Next, the operation in the above configuration will be described.

In FIG. 1, the print medium P inserted from the insertion port 18 is shown.
Is transported to the recording unit 12. In the recording unit 12, the toner T is supplied to the brush roller 30 by the supply roller. At this time, the toner T frictionally contacts the supply roller 36 and the brush roller 30 and is charged, for example, positively (+). The toner T charged to plus (+) is a brush roller 30
It is carried on. Then, the toner T excessively supplied to the brush roller 30 is scraped off by the layer thickness regulating member 38. As a result, a uniform toner layer is formed on the brush roller 30.

Then, in the vicinity of the aperture electrode 32, the scraping member 40
Thereby, the brush roller 30 is scraped. Then, 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 32 in the form of a cloud.

The cloud of the toner T charged to the plus (+) is attracted to the first electrode layer 48 connected to the minus (-) power supply E1. The flow of the toner T is modulated by the voltage applied from the signal source S to the second electrode layer 50 of the aperture electrode 32.

For example, a maximum of -250 V is applied to the second electrode layer 50 as a toner passing voltage, and 100 V is applied as a toner cutoff voltage.

Next, the modulated positively (+) charged toner T flies toward the counter electrode 34 by the negative (−) DC power supply E2 connected to the counter electrode 34. Then, the toner T is attracted to the print medium P guided by the guide 24 and the pair of auxiliary rollers 56.

Thereafter, the print medium P is transported to the heat fixing unit 14. At this location, the image on the print medium P is fixed by being pressed by the heat roller 60 and the press roller 58. Since this fixing method is conventional, detailed description is omitted.

Finally, the print medium P on which an image has been formed is conveyed to the take-out port 20 via the guide 24, and thereafter taken out.

Here, the density contrast ratio of the print output is represented by the following equation (1).

Density contrast ratio = D _MAX / D ₀ D _MAX is the maximum toner passing voltage (-250 V) on the second electrode layer 50
Is applied to the print medium P when the toner flow is modulated, and the toner density D ₀ attached to the print medium P is applied to the second electrode layer 50 by applying the toner cutoff voltage (100 V) to the print medium P when the toner flow is modulated. Density of Toner Attached to P FIG. 3 shows the relationship between the toner flying voltage (0 to -200 V) applied to the first electrode layer 48 and the density contrast ratio.

In this figure, it can be seen that the higher the toner flying voltage applied to the first electrode layer, the higher the density contrast ratio of the print output. This is because the supply amount of the toner to the print medium P increases when the toner flying voltage is applied to the first electrode layer 48.

Further, when a toner cutoff voltage is applied to the second electrode layer 50, a strong toner cutoff electric field is generated inside the aperture 44 due to the toner flying voltage applied to the first electrode layer, and the toner to the print medium P The blocking is effected effectively.

[Effects of the Invention] As described above, according to the toner jet recording apparatus of the present invention, the first electrode layer has a constant bias having a polarity opposite to the charge polarity of the charged toner so that the charged toner flies in this direction. Since the supply of the toner to the print medium is increased by the application of the voltage, it is possible to form a print image with a sufficiently high contrast for print output.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a toner jet recording apparatus of the present invention, FIG. 2 is a perspective view showing a configuration of an aperture electrode provided in the embodiment of FIG. 1, and FIG. FIG. 4 is a diagram illustrating a density contrast ratio of a print output. 10: toner jet recording device, 12: recording unit, 14: heat fixing unit, 18: insertion port, 20: take-out port, 24: guide, 30: brush roller, 32: aperture electrode, 34 ... counter electrode, 36 ... supply roller, 38 ... layer thickness regulating member, 40 ... scraping member, 44 ... aperture, 46 ... insulating layer, 48 ... first electrode layer, 50 ... second Electrode layer, 52 ... Insulating layer, 56 ... Auxiliary roller, 58 ... Heat roller, 60 ... Press roller, E1, E2 ... DC power supply, K ... Toner case, P ... Print medium, S ... Signal source, T: toner.

Claims (1)

(57) [Claims] 1. A toner supply means for supplying a charged toner, a first electrode layer provided on the toner supply means side, an insulating layer having an opening formed therein, and a second electrode layer are sequentially provided. An aperture electrode that modulates the charged toner by applying a bias voltage to the first electrode layer having a polarity opposite to that of the charged toner so that the charged toner flies in the direction of the first electrode layer. A toner jet recording apparatus comprising: a power supply;