JPH0453974A - Image forming device - Google Patents

Abstract

PURPOSE:To improve the quality of an image by dividing a slit formed on a substrate into toner passing holes by plural grids and applying ultrasonic vibration to a pair of grids which are adjacent to each other so that toner may pass through the respective toner passing holes. CONSTITUTION:The slit 32 of the substrate 31 is divided along the longitudinal direction into the plural toner passing holes 31a by the plural grids 33. Then, the ultrasonic vibration is applied to a pair of grids 33 which are adjacent to each other by an ultrasonic generating means 40 driven by an image information generating means 50. Therefore, toner passes through the toner passing holes 31a between the slit 32 and a pair of grids 33 to form the image on a recording paper 70. Thus, the high-quality image is formed.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an image forming apparatus using powder toner.

(Prior Art) An image forming apparatus that forms small-diameter dots using powdered toner and forms an image using an aggregate of many dots is disclosed in, for example, Japanese Patent Laid-Open No. 2-22071. . The image forming apparatus disclosed in this publication includes a flat electrode and a large number of grid electrodes, each of which is parallel to the flat electrode.

Each grid electrode is parallel to each other with equal spacing between them, and by controlling the electric field between each grid electrode and the flat plate electrode, toner charged to a predetermined polarity is passed between the grids. to form an image.

(Problems to be Solved by the Invention) In such an image forming apparatus, in order to further improve image quality, it is necessary to reduce the interval between grid electrodes through which toner passes, thereby making toner dots smaller. However, if the spacing between the grid electrodes is narrowed, there is a risk that toner will become clogged between the grid electrodes. Furthermore, if the interval between the grid electrodes becomes narrow, there is a risk that the electric field will affect grid electrodes that do not need to pass toner. As a result, dots may be formed in areas where dots do not need to be formed, and the quality of the formed image may be significantly degraded.

The present invention solves the above-mentioned conventional problems, and its purpose is to provide an image forming apparatus that can form high-quality images.

(Means for Solving the Problems) The image forming apparatus of the present invention is provided above recording paper that is advanced in a predetermined direction,
A substrate having a slit extending in a direction intersecting the traveling direction of the recording paper; and a plurality of holes provided on the upper surface of the substrate so as to divide the slit into a plurality of toner passage holes along the longitudinal direction. a grid; means for supplying toner onto each grid from above the substrate; ultrasonic vibration generating means for applying ultrasonic vibration to each grid; and ultrasonic vibration generating means for a pair of mutually adjacent grids. An image information generating means that is driven according to the image information and causes the toner to fall into the toner passage hole between both grids, and a pair of electrodes that form an electric field so that the toner that has passed through the slit in the substrate falls onto the recording paper. The above object is thereby achieved.

(Function) In the image forming apparatus of the present invention, the slit of the substrate is divided into a plurality of toner passage holes along the longitudinal direction by a plurality of grids, and a pair of mutually adjacent grids are driven by an image information generating means. By applying ultrasonic vibrations by the ultrasonic generating means, the toner passes through the slits and the toner passage holes between the pair of grids, and an image is formed on the recording paper.

(Example) Examples of the present invention will be described below.

As shown in FIG. 1, the image forming apparatus of the present invention includes a toner container 10 containing powder toner. The upper part of the toner storage container 10 communicates with a toner storage section such as a toner hopper, and the toner storage container 10 is sequentially replenished with toner. An opening 11 is provided at the lower part of the space where the toner is stored in the toner storage container 10, and a toner supply roller 20, such as a sponge roller, is disposed within the opening 11 as a toner supply means.
The upper part of the is fitted. The toner contained in the toner container 10 is sequentially supplied downward by the rotation of the toner supply roller 20 .

Below the toner supply roller 20, a toner control means 30 is provided.
is provided in close proximity to the toner supply roller 20. The toner control means 30 includes an image information generation means 50.
An image signal is given from The image information generating means 50 is
It operates in response to signals from a device such as a word processor, facsimile, or computer, and generates electrical signals in accordance with image information.

According to this electric signal, the powder toner fed from the toner supply roller 20 is controlled to fall downward by the toner control means 30, and a predetermined toner image is formed on the recording paper 70. The toner control means 30 may be in pressure contact with the toner supply roller 20.

A base electrode 60 is provided below the toner control means 30 so as to face the toner control means 30 .

On the base electrode 60 is a recording paper 7 on which a toner image is formed.
0 is placed. The recording paper 70 is advanced in the direction shown by arrow A. The base electrode 60 may move in the direction of arrow A together with the recording paper placed thereon, or the base electrode 60 may be fixed and only the recording paper 70 may be moved by the recording paper transport means. good. When a predetermined toner image is formed on the recording paper 70 by the toner control means 30, the recording paper 70 is conveyed to a predetermined fixing device (not shown), and the toner image is transferred to the recording paper 7 by the fixing device.
Fixed to 0.

The toner control means 30 has a horizontal substrate 31, as shown in FIGS. 2 and 3. As shown in FIGS. The substrate 31 has a horizontally long slit 32 that passes through it in the vertical direction.

The slit 32 is elongated in the axial direction of the toner supply roller 20, and therefore in a direction perpendicular to the traveling direction of the recording paper 70.

A large number of linear grids 33 are arranged on the upper surface of the substrate 31 so as to be substantially perpendicular to the longitudinal direction of the slits 32 . The grids 33 are arranged at predetermined equal intervals in the longitudinal direction of the slit 32, and each grid 33 divides the slit 32 into a large number of toner passage holes 31a along the longitudinal direction. Each grid 33 is preferably arranged close to each other in order to downsize and increase the density of the toner passage holes 31a. Toner supplied from the toner supply roller 20 is placed on each grid 33 . The interval between adjacent grids 33 is sufficiently small, and there is no possibility that the toner supplied from the toner supply roller 20 will pass between them under normal conditions.

Between the substrate 31 and each grid 33, there is an ultrasonic vibration generating means 40.40 using, for example, a piezo element, which applies ultrasonic vibration to each grid 33. ...is provided. Each ultrasonic vibration generating means 40 includes:
Image signals output from the image information generating means 50 are respectively provided. This image information generating means 50 is configured to operate the ultrasonic vibration generating means 40 of each grid, respectively, in order to selectively vibrate ultrasonic waves in a pair of adjacent grids 33 and 33 according to the image signal.

A common electrode 35 is attached to the lower surface of the substrate 31, and is provided with an opening 35a having the same shape as the slit 32. The opening 35a of the common electrode 35 is the slit 3.
2 is in a consistent state.

Below the common electrode 33, the base electrode 60 is disposed horizontally, as described above. The base electrode 60 and the common electrode 35 attached to the lower surface of the substrate 31 form a predetermined electric field therebetween.

The toner that has passed through the toner passage hole 31a in the toner control means 30 is formed by a common electrode 35 on the toner supply side of the toner control means 30 and a base electrode 6o provided on the toner passage side of the toner control means 3o. The recording paper 7 placed on the base electrode 6o is
o. The potential difference between the base electrode 6° and the common electrode 35, that is, the electric field strength, is determined by the voltage changing means 61.
It is set to be changed by.

An image forming process using an image forming apparatus having such a configuration will be described.

When the toner supply roller 2o rotates, the toner storage container 1
0 toner is supplied onto each grid 33 of the toner control means 3o.

Since the interval between adjacent grids is sufficiently narrow, the toner that has fallen onto each grid 33 may naturally fall into each toner passage hole 31a divided by each grid 33 in the slit 32 of the substrate 31. In such a state, in order to apply ultrasonic vibration to a pair of grids 33 sandwiching the toner passage hole 31a through which the toner is to pass, the image information generating means 50 activates a predetermined ultrasonic vibration generating means 4o, respectively. As a result, ultrasonic vibrations are applied to a pair of mutually adjacent grids 33, and the toner on each grid 33 falls between the two grids 33.

When the toner passes through the portion of the slit 32 corresponding to the toner passing hole 31a, the toner is attracted to the base electrode 60 by the electric field formed between the common electrode 35 and the base electrode 60, and the toner is attracted to the base electrode 60. It adheres to the recording paper 70 on top of the recording paper 60 .

The image information generating means 50 controls the ultrasonic vibration generating means 40 of each grid 33 so that ultrasonic vibrations are not applied to adjacent grids 33 when there is no need to form an image.
is controlled.

The electric field strength between the common electrode 35 and the base electrode 60 is appropriately changed by the voltage changing means 61, and the toner passing through the toner passage hole 31a in the slit 32 is transferred to the recording paper 7.
0 to form a dot of an appropriate diameter. By changing the dot diameter, the density of the image formed on the recording paper 70 is changed.

(Effects of the Invention) As described above, the image forming apparatus of the present invention divides the slit formed in the substrate into toner passage holes by a plurality of grids, and applies ultrasonic vibration to a pair of mutually adjacent grids. By applying the toner, the toner is allowed to pass through each toner passing hole, so that the toner passing holes can be made denser and smaller, and the image quality can be further improved.

4. Figure 1 is a block diagram showing an example of the image forming apparatus of the present invention, Figure 2 is a block diagram of its main parts, and Figure 3 is a plan cross-sectional view thereof.

DESCRIPTION OF SYMBOLS 10... Toner storage container, 20... Toner supply roller, 30... Toner control means, 31... Substrate, 31
a... Toner passage hole, 32... Slit, 33...
- Grid, 35... Common electrode, 50... Image information generating means, 60... Base electrode.

that's all

Claims (1)

[Claims] 1. A substrate having a slit provided above the recording paper that is advanced in a predetermined direction and extending in a direction intersecting the traveling direction of the recording paper; a large number of grids provided on the upper surface of the substrate so as to be divided into a plurality of toner passage holes along the substrate; means for supplying toner onto each grid from above the substrate; and ultrasonic vibration for each grid. an image information generating means for driving the ultrasonic vibration generating means of a pair of mutually adjacent grids according to image information to cause the toner to fall into the toner passage hole between the two grids; An image forming apparatus comprising: a pair of electrodes that form an electric field so that toner that has passed through a slit in a substrate falls onto recording paper.