# US 6,715,858 B1 · Image-forming device

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- Number: US 6,715,858 B1
- Document ID: US6715858B1
- Status: Granted
- Kind: B1
- Application number: 09/979,225
- Filed: 2002-05-10
- Granted: 2004-04-06
- Earliest claimed: 1999-05-19
- Assignees: Matsushita Electric Industrial Co., Ltd.
- Inventors: Katsutoshi Ogawa; Masahiro Aizawa; Akira Kumon; Akira Fukano
- Web page: https://patentgrep.com/patent/US6715858B1

## CPC

- B41J 2/4155: {for direct electrostatic printing [DEP]}
- G03G 2217/0025: where the toner starts moving from behind the electrode array, e.g. a mask of holes
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

An image forming device includes a developer carrier (1) for carrying a charged developer (2), and a developer passing controller (3) for applying a voltage corresponding to an image. signal to a plurality of control electrodes (10) to control the passing of said developer (2), the developer passing controller having a plurality of developer passing holes (4) through which the developer (2) passes and said control electrodes being arranged to surround the surroundings of the developer passing holes. The width (W1) of a control electrode row (5) in the longitudinal direction where the control electrodes (10) are arranged is wider than the width (W2) of an image forming area, and both ends (B1, B2) of the control electrode row (5) in the longitudinal direction are arranged outside the width (W2) of an image forming area.

## Claims

### Claim 1

An image forming device comprising:
a developer carrier (1) for carrying a charged developer (2);
a developer passing controller (3) for controlling the passing of said developer (2) by applying a voltage corresponding to an image signal to a plurality of control electrodes (10), the developer passing controller having a plurality of developer passing holes (4) through which the developer (2) passes and said control electrodes being arranged to surround the surroundings of the developer passing holes;
an image receiving member (7) for receiving said developer (2) passed through; and
a backside electrode (6) for drawing said developer (2), the backside electrode being installed at the back side of said image receiving member (7),
wherein the width of a control electrode row (5) in a longitudinal direction, where the control electrodes (10) are arranged, is wider than a width of an image forming area in a direction perpendicular to a moving direction of the image receiving member (7), and both ends of the control electrode row (5) in the longitudinal direction are arranged outside the width of an image forming area.

### Claim 2 (depends on 1)

The image forming device according to claim 1, wherein a voltage is applied to a portion outside the width of an image forming area of the control electrode row (5) so as to obstruct the passing of said developer (2) through the developer passing hole (4) at least during time when image formation is operated.

### Claim 3 (depends on 1)

The image forming device according to claim 1, wherein said developer passing holes (4) are formed only in the portion arranged inside from the maximum width of an image forming area of the control electrode row (5).

### Claim 4 (depends on 1)

The image forming device according to claim 1, further comprising a correction member for correcting an address of said control electrode (10), where the image signal is supplied, based on a relative position of said developer passing controller (3) to the image receiving member (7).

### Claim 5 (depends on 4)

The image forming device according to claim 4, wherein said correction member comprises a detection member (17) for detecting the relative position of said developer passing controller (3) to said image receiving member (7), a calculating member (18) for calculating correcting data based on the detection signal sent from said detection member (17), and a storage member (20) for storing the correcting data obtained from the calculating member (18).

### Claim 6 (depends on 5)

The image forming device according to claim 5, wherein said detection member (17) and said calculating member (18) are detachable from the image forming device.

### Claim 7 (depends on 4, 5, 6)

The image forming device according to any of claims 4 to 6, wherein a plurality of said developer carriers (1) and a plurality of said developer passing controllers (3) opposed to said developer carriers (1) are installed.

### Claim 8 (depends on 4, 5, 6)

The image forming device according to any of claims 4 to 6, wherein said developer passing controller (3) is detachable from a main body of the image forming device and the correcting operation by the correction member is executed every time when said developer passing controller (3) is attached in the main body of the image forming device.

### Claim 9

An image forming device comprising:
a developer carrier (1) for carrying a charged developer (2);
a developer passing controller (3) for controlling the passing of said developer (2) by applying a voltage corresponding to an image signal to a plurality of control electrodes (10), the developer passing controller having a plurality of developer passing holes (4) through which the developer (2) passes and said control electrodes being arranged to surround the surroundings of the developer passing holes;
a voltage supplying member (16) for supplying a voltage corresponding to the image signal to the control electrodes (10);
an image receiving member (7) for receiving the developer (2) passed through; and
a backside electrode (6) for drawing the developer (2), the backside electrode being installed at the back side of the image receiving member (7),
wherein an external electrode (22) receiving a desired voltage is installed outside at both ends of a control electrode row (5) where the control electrodes (10) are arranged.

### Claim 10 (depends on 9)

The image forming device according to claim 9, wherein said external electrode (22) is extended in parallel to a lead line (23) connecting said control electrode (10) with the voltage supplying member (16).

### Claim 11 (depends on 9, 10)

The image forming device according to any of claims 9 and 10, wherein a voltage of the same polarity as that of developer (2) is always applied to the external electrode (22).

### Claim 12 (depends on 9, 10)

The image forming device according to any of claims 9 and 10, wherein an alternating current voltage is superimposed to said external electrode (22).

### Claim 13 (depends on 9, 10)

The image forming device according to any of claims 9 and 10, wherein a voltage applied to the control electrode (10), which obstructs the passing of developer (2), is applied to said external electrode (22) during time of the operation of image formation.

### Claim 14

An image forming device comprising:
a developer carrier (1) for carrying a charged developer (2);
a developer passing controller (3) for controlling the passing of said developer (2) by applying a voltage corresponding to an image signal to a plurality of control electrodes (10), the developer passing controller having a plurality of developer passing holes (4) through which the developer (2) passes and said control electrodes being arranged to surround the surroundings of the developer passing holes;
an image receiving member (7) for receiving said developer (2) passed through; and
a backside electrode (6) for drawing said developer (2), the backside electrode being installed at the back side of the image receiving member (7),
wherein the width of an electrode row (31), arranged in an area which is adjacent to said developer carrier (1) in said developer passing controller (3), is narrower than the width of a developer layer held on said developer carrier (1), viewed from a direction perpendicular to a moving direction of said image receiving member (7), and both ends of the electrode row (31) are arranged inside both ends of the developer layer.

### Claim 15

An image forming device comprising:
a developer carrier (1) for carrying a charged developer (2);
a developer passing controller (3) for controlling the passing of said developer (2) by applying a voltage corresponding to an image signal to a plurality of control electrodes (10), the developer passing controller having a plurality of developer passing holes (4) through which the developer (2) passes and said control electrodes being arranged to surround the surroundings of the developer passing holes;
a maintaining member (32) for maintaining a distance from a developer layer on said developer carrier (1) to said developer passing controller (3) constantly by contacting a developer layer on said developer carrier (1) and the developer passing controller (3);
an image receiving member (7) for receiving said developer (2) passed through; and
a backside electrode (6) for drawing said developer (2), the backside electrode being installed at the back side of the image receiving member (7),
wherein the width of an electrode row (31), arranged in an area which is adjacent to said developer carrier (1) in said developer passing controller (3), is narrower than the width of the maintaining member (32), viewed from a direction perpendicular to a moving direction of the image receiving member (7), and both ends of the electrode row (31) are arranged inside both ends of said maintaining member (32).

### Claim 16

An image forming device comprising:
a developer carrier (1) for carrying a charged developer (2);
a developer passing controller (3) for controlling the passing of said developer (2) by applying a voltage corresponding to an image signal to a plurality of control electrodes (10), the developer passing controller having a plurality of developer passing holes (4) through which the developer (2) passes and said control electrodes being arranged to surround the surroundings of the developer passing holes;
an image receiving member (7) for receiving said developer (2) passed through; and
a backside electrode (6) for drawing said developer (2), the backside electrode being installed at the back side of the image receiving member (7),
wherein the width of said image receiving member (7) is wider than the width of the backside electrode (6), viewed from a direction perpendicular to a moving direction of said image receiving member (7), and both ends of said image receiving member (7) are arranged outside both ends of the backside electrode (6).

### Claim 17

An image forming device comprising:
a developer carrier (1) for carrying a charged developer (2);
a developer passing controller (3) for controlling the passing of said developer (2) by applying a voltage corresponding to an image signal to a plurality of control electrodes (10), the developer passing controller having a plurality of developer passing holes (4) through which the developer (2) passes and said control electrodes being arranged to surround the surroundings of the developer passing holes;
an image receiving member (7) for receiving said developer (2) passed through; and
a backside electrode (6) for drawing said developer (2), the backside electrode being installed at the back side of the image receiving member (7),
wherein the width of the developer passing controller (3) is wider than either of the width of the developer carrier (1) and the width of the backside electrode (6), viewed from a direction perpendicular to a moving direction of said image receiving member (7), and both ends of the developer passing controller (3) are arranged outside either of both ends of the developer carrier (1) and both ends of the backside electrode(6).

### Claim 18

An image forming device comprising:
a developer carrier (1) for carrying a charged developer (2);
a developer passing controller (3) for controlling the passing of said developer (2) by applying a voltage corresponding to an image signal to a plurality of control electrodes (10), the developer passing controller having a plurality of developer passing holes (4) through which the developer (2) passes and said control electrodes being arranged to surround the surroundings of the developer passing holes;
a maintaining member (32) for maintaining a distance from a developer layer on said developer carrier (1) to said developer passing controller (3) constantly by contacting the developer layer on said developer carrier (1) and the developer passing controller (3);
an image receiving member (7) for receiving said developer (2) passed through; and
a backside electrode (6) for drawing said developer (2), the backside electrode being installed at the back side of the image receiving member (7),
wherein the width of the developer layer is narrower than the width of the maintaining member (32), viewed from a direction perpendicular to a moving direction of the image receiving member (7), and both ends of the developer layer are arranged inside from both ends of the maintaining member (32).

### Claim 19

An image forming device comprising:
a developer carrier (1) for carrying a charged developer (2);
a developer passing controller (3) for controlling the passing of said developer (2) by applying a voltage corresponding to an image signal to a plurality of control electrodes (10), the developer passing controller having a plurality of developer passing holes (4) through which the developer (2) passes and said control electrodes being arranged to surround the surroundings of the developer passing holes;
a maintaining member (32) for maintaining a distance from a developer layer on said developer carrier (1) to said developer passing controller (3) constantly by contacting the developer layer on said developer carrier (1) and the developer passing controller (3);
an image receiving member (7) for receiving said developer (2) passed through; and
a backside electrode (6) for drawing said developer (2), the backside electrode being installed at the back side of the image receiving member (7),
wherein the width of the developer passing controller (3) is wider than the width of the maintaining member (32), viewed from a direction perpendicular to a moving direction of the image receiving member (7), and both ends of the developer passing controller (3) are arranged outside both ends of the maintaining member (32).

### Claim 20

An image forming device comprising:
a developer carrier (1) for carrying a charged developer (2);
a developer passing controller (3) for controlling the passing of said developer (2) by applying a voltage corresponding to an image signal to a plurality of control electrodes (10), the developer passing controller having a plurality of developer passing holes (4) through which the developer (2) passes and said control electrodes being arranged to surround the surroundings of the developer passing holes;
a maintaining member (32) for maintaining a distance from a developer layer on said developer carrier (1) to said developer passing controller (3) constantly by contacting the developer layer on said developer carrier (1) and the developer passing controller (3);
an image receiving member (7) for receiving said developer (2) passed through; and
a backside electrode (6) for drawing said developer (2), the backside electrode being installed at the back side of the image receiving member (7),
wherein the width of said developer carrier (1) is wider than the width of the maintaining member (32), viewed from a direction perpendicular to a moving direction of said image receiving member (7), and both ends of said developer carrier (1) are arranged outside both ends of said maintaining member (32).

### Claim 21

An image forming device comprising:
a developer carrier (1) for carrying a charged developer (2);
a developer passing controller (3) for controlling the passing of said developer (2) by applying a voltage corresponding to an image signal to a plurality of control electrodes (10), the developer passing controller having a plurality of developer passing holes (4) through which the developer (2) passes and said control electrodes being arranged he to surround the surroundings of the developer passing holes;
an image receiving member (7) for receiving said developer (2) passed through;
a backside electrode (6) for drawing said developer (2) with electromagnetic force, the backside electrode having an opening (33) and being installed at the back side of the image receiving member (7); and
an airflow generating member (34) for drawing said developer (2) adhered to the developer passing controller (3) with airflow,
wherein the width of the opening (33) is wider than the width of an electrode row (31) located in a region which is adjacent to the developer carrier (1) in said developer passing controller (3), viewed from a direction perpendicular to a moving direction of said image receiving member (7), and both ends of the opening (33) are arranged outside both ends of the electrode row (31).

### Claim 22

An image forming device comprising:
a developer carrier (1) for carrying a charged developer (2);
a developer passing controller (3) for controlling the passing of said developer (2) by applying a voltage corresponding to an image signal to a plurality of control electrodes (10), the developer passing controller having a plurality of developer passing holes (4) through which the developer (2) passes and said control electrodes being arranged to surround the surroundings of the developer passing holes;
an image receiving member (35) for receiving said developer (2) passed through, the image receiving member (35) having a second opening (38);
a backside electrode (6) for drawing said developer (2) with electromagnetic force, the backside electrode having a first opening (33) and being installed at the back side of the image receiving member (35); and
an airflow generating member (34) for drawing said developer (2) adhered to the developer passing controller (3) to the first opening (33) through the second opening (38) with airflow,
wherein the width of said first opening (33) is wider than the width of said second opening (38), viewed from a direction perpendicular to a moving direction of said image receiving member (35), and both ends of said first opening (33) are arranged outside both ends of said second opening (38).

### Claim 23 (depends on 14, 15, 21)

The image forming device according to any of claims 14, 15 and 21, wherein said electrode row (31) has a control electrode row where said control electrodes (10) are arranged, and an external electrode (30) for receiving a desired voltage and being arranged outside both ends of the control electrode row in the longitudinal direction.

### Claim 24 (depends on 16)

The image forming device according to claim 16, wherein an insulating layer is provided in an area on the surface of said image receiving member (7) opposed to said developer passing controller (3), where both ends of said backside electrode (6) are located in the back.

### Claim 25 (depends on 19, 20)

The image forming device according to any of claims 19 and 20, wherein said maintaining member (32) is made of an insulating material.