# US 5,144,343 A · Image recording method and apparatus

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- Number: US 5,144,343 A
- Document ID: US5144343A
- Status: Granted
- Kind: A
- Application number: 07/541,313
- Filed: 1990-06-21
- Granted: 1992-09-01
- Earliest claimed: 1989-06-21
- Assignees: Hitachi, Ltd.; Hitachi Metals, Ltd.; Hitachi Koki Co., Ltd.
- Inventors: Sayoko Oba; Kenji Okuna; Katsumi Muroi; Katsubumi Ouchi; Tsutomu Iimura; Ryoji Kojima
- Web page: https://patentgrep.com/patent/US5144343A

## CPC

- G03G 15/348: {using a stylus or a multi-styli array}
- G03G 2217/0033: where the toner is held behind a gate electrode array until being released
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

An image recording apparatus including a recording electrode having electrode needles aligned in columns, a driving circuit for individually applying an image recording voltage to the electrode needles of the recording electrode, a recording medium composed of a conductive layer and a surface insulating layer, and a voltage circuit for applying a predetermined voltage between the recording medium and the electrode needles, whereby fog on the recorded image can be avoided.

## Claims

### Claim 1

An image recording apparatus comprising:
a recording electrode having electrode needles aligned in columns;
a driving circuit for individually applying an image recording potential and a non-image recording potential to said electrode needles;
a recording medium composed of an insulating layer with an electrically conductive layer on the surface thereof;
voltage applying means for applying a D.C. potential to said conductive layer relative to the non-image recording potential, whereby electrically conductive toner is supplied between said recording electrode and said recording medium, said driving circuit individually applying an image potential to said electrode needles to record a toner image on said recording medium.

### Claim 2 (depends on 1)

An image recording apparatus according to claim 1, wherein said voltage applying means applies a D.C. potential of -5 V to +5 V.

### Claim 3

An image recording apparatus comprising:
a recording electrode having electrode needles aligned in columns;
a recording medium composed of an insulating layer with an electrically conductive layer on the surface thereof;
means for supplying electrically conductive toner between said recording electrode and said recording medium;
a driving circuit for individually applying an image recording potential and a non-image recording potential to said electrode needles to provide a toner image on said recording medium; and
bias voltage applying means for adding a bias voltage to said image recording potential and said non-image recording potential relative to said electrically conductive layer.

### Claim 4

An image recording method for use in an image recording apparatus comprising a recording electrode having electrode needles aligned in columns; a recording medium composed of an insulating layer with an electrically conductive layer on the surface thereof; and a driving circuit for individually applying an image recording potential and a non-image recording potential to said electrode needles to provide a toner image on said recording medium; said image recording method comprising the steps;
supplying electrically conductive toner between said recording electrode and said recording medium;
activating said driving circuit to individually and selectively apply an image recording potential and a non-image recording potential to said electrode needles to record a toner image on said recording medium; and
applying a biasing potential to said electrically conductive layer to cause the potential at said electrically conductive layer to be relatively different from the image recording voltage and the non-image recording voltage.

### Claim 5 (depends on 4)

An image recording method according to claim 4, wherein said bias potential applying means causes the potential difference between the recording potential and the potential at said electrically conductive layer to be larger than the potential difference between the non-image recording potential and the potential at said electrically conductive layer.

### Claim 6 (depends on 5)

An image recording method according to claim 5, wherein the potential difference between the non-image recording potential and the potential at said electrically conductive layer is 0 V to +5 V.