US4262294A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic printing apparatus comprising improved electrode drive means
Assignee: Ricoh Co Ltd
•
Filing: 1978-07-31
•
Granted: 1981-04-14
•
Expires: 1998-07-31
Abstract
Abstract A sheet of copy paper (24) is moved perpendicular to a linear array (22) of printing electrodes (221, 222, 223, 224 . . . ). The electrodes (221, 222, 223, 224 . . . ) are selectively energized to form an electrostatic charge pattern on the copy sheet (24) corresponding to one horizontal scan line of an original document. The electrostatic charge pattern is developed by a toner and the resulting toner image fixed to the copy sheet (24). The electrodes (221, 222, 223, 224 . . . ) are divided into a first set (221, 223, 225 . . . ) and a second set (222, 224, 226 . . . ), the electrodes in the second set (222, 224, 226 . . . ) being alternatingly spaced from the electrodes in the first set (221, 223, 225 . . . ) along the length of the array (22). The first set (221, 223, 225 . . . ) of electrodes are selectively energized during a first time period (t1) and the second set (222, 224, 226 . . . ) of electrodes are selectively energized during a subsequent second time period (t2). The second time period (t2) may be made longer than the first time period (t1) and/or a voltage (V2) applied to the second set (222, 224, 226 . . . ) of electrodes may be made higher than a voltage (V1) applied to the first set (221, 223, 225 . . . ) of electrodes.
Inventors
- 👤 Kazuyuki Hara
- 👤 Mitsuru Kondo
- 👤 Takeshi Kamada
- 👤 Noboru Furukawa
- 👤 Tamio Ohori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:35
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/385; B41J2/41
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
143 words
An electrostatic printing apparatus comprising: a plurality of first printing electrodes arranged in a first row; and a plurality of second printing electrodes arranged in a second row adjacent to the first printing electrodes, the second printing electrodes being alternatingly spaced from the first printing electrodes in a direction parallel to the first and second rows in such a manner that each first printing electrode is spaced between two adjacent second printing electrodes and vice-versa, characterized by comprising: drive means for selectively energizing the first and second printing electrodes to form a linear electrostatic pattern on a printing medium disposed adjacent to the first and second printing electrodes, the drive means being constructed to energize selected first printing electrodes during a first time period and subsequently energize selected second printing electrodes during a second time period, the first and second rows being colinear.
Claim 2
Dependent Claim
143 words
An electrostatic printing apparatus comprising: a plurality of first printing electrodes arranged in a first row; and a plurality of second printing electrodes arranged in a second row adjacent to the first printing electrodes, the second printing electrodes being alternatingly spaced from the first printing electrodes in a direction parallel to the first and second rows in such a manner that each first printing electrode is spaced between two adjacent second printing electrodes and vice-versa, characterized by comprising: drive means for selectively energizing the first and second printing electrodes to form a linear electrostatic pattern on a printing medium disposed adjacent to the first and second printing electrodes, the drive means being constructed to energize selected first printing electrodes during a first time period and subsequently energize selected second printing electrodes during a second time period, the first and second rows being colinear.
Claim 3
Dependent Claim
34 words
An apparatus as in claim 1, further comprising an auxiliary electrode disposed adjacent to the first and second printing electrodes, the drive means energizing the auxiliary electrode during the first and second time periods.
Claim 4
Dependent Claim
111 words
An apparatus as in claim 1, further comprising a plurality of first AND gate means having outputs connected to the first printing electrodes respectively and a plurality of second AND gate means having outputs connected to the second printing electrodes respectively, inputs of first and second AND gate means in corresponding positions being connected together to receive respective data signals corresponding to the electrostatic pattern, other inputs of all of the first AND gate means being connected together to receive a first voltage during the first time period, other inputs of all of the second AND gate means being connected together to receive a second voltage during the second time period.
Claim 5
Dependent Claim
146 words
An electrostatic printing apparatus comprising: a plurality of first printing electrodes arranged in a first row; and a plurality of second printing electrodes arranged in a second row adjacent to the first printing electrodes, the second printing electrodes being alternatingly spaced from the first printing electrodes in a direction parallel to the first and second rows in such a manner that each first printing electrode is spaced between two adjacent second printing electrodes and vice-versa, characterized by comprising: drive means for selectively energizing the first and second printing electrodes to form an electrostatic pattern on a printing medium disposed adjacent to the first and second printing electrodes, the drive means being constructed to energize selected first printing electrodes during a first time period and subsequently energize selected second printing electrodes during a second time period, the second time period being longer than the first time period.
Claim 6
Dependent Claim
146 words
An electrostatic printing apparatus comprising: a plurality of first printing electrodes arranged in a first row; and a plurality of second printing electrodes arranged in a second row adjacent to the first printing electrodes, the second printing electrodes being alternatingly spaced from the first printing electrodes in a direction parallel to the first and second rows in such a manner that each first printing electrode is spaced between two adjacent second printing electrodes and vice-versa, characterized by comprising: drive means for selectively energizing the first and second printing electrodes to form an electrostatic pattern on a printing medium disposed adjacent to the first and second printing electrodes, the drive means being constructed to energize selected first printing electrodes during a first time period and subsequently energize selected second printing electrodes during a second time period, the second time period being longer than the first time period.
Claim 7
Dependent Claim
26 words
An apparatus as in claim 4, in which the drive means is constructed to energize the selected first and second printing electrodes with a same voltage.
Claim 8
Dependent Claim
170 words
An electrostatic printing apparatus comprising: a plurality of first printing electrodes arranged in a first row; and a plurality of second printing electrodes arranged in a second row adjacent to the first printing electrodes, the second printing electrodes being alternatingly spaced from the first printing electrodes in a direction parallel to the first and second rows in such a manner that each first printing electrode is spaced between two adjacent second printing electrodes and vice-versa, characterized by comprising: drive means for selectively energizing the first and second printing electrodes to form an electrostatic pattern on a printing medium disposed adjacent to the first and second printing electrodes, the drive means being constructed to energize selected first printing electrodes during a first time period and subsequently energize selected second printing electrodes during a second time period, the drive means being constructed to energize the selected first printing electrodes with a first voltage and to energize the selected second printing electrodes with a second voltage which is higher than the first voltage.
Claim 9
Dependent Claim
170 words
An electrostatic printing apparatus comprising: a plurality of first printing electrodes arranged in a first row; and a plurality of second printing electrodes arranged in a second row adjacent to the first printing electrodes, the second printing electrodes being alternatingly spaced from the first printing electrodes in a direction parallel to the first and second rows in such a manner that each first printing electrode is spaced between two adjacent second printing electrodes and vice-versa, characterized by comprising: drive means for selectively energizing the first and second printing electrodes to form an electrostatic pattern on a printing medium disposed adjacent to the first and second printing electrodes, the drive means being constructed to energize selected first printing electrodes during a first time period and subsequently energize selected second printing electrodes during a second time period, the drive means being constructed to energize the selected first printing electrodes with a first voltage and to energize the selected second printing electrodes with a second voltage which is higher than the first voltage.
Claim 10
Dependent Claim
15 words
An apparatus as in claim 6, in which the first and time periods are equal.
Claim 11
Dependent Claim
197 words
An electrostatic printing apparatus comprising: a plurality of first printing electrodes arranged in a first row; and a plurality of second printing electrodes arranged in a second row adjacent to the first printing electrodes, the second printing electrodes being alternatingly spaced from the first printing electrodes in a direction parallel to the first and second rows in such a manner that each first printing electrode is spaced between two adjacent second printing electrodes and vice-versa, characterized by comprising: drive means for selectively energizing the first and second printing electrodes to form an electrostatic pattern on a printing medium disposed adjacent to the first and second printing electrodes, the drive means being constructed to energize selected first printing electrodes during a first time period and subsequently energize second printing electrodes during a second time period; and an auxiliary electrode disposed adjacent to the first and second printing electrodes, the drive means energizing the auxiliary electrode during the first and second time periods; the drive means being constructed to energize the auxiliary electrode with a first voltage during the first time period and with a second voltage which is higher than the first voltage during the second time period.
Claim 12
Dependent Claim
197 words
An electrostatic printing apparatus comprising: a plurality of first printing electrodes arranged in a first row; and a plurality of second printing electrodes arranged in a second row adjacent to the first printing electrodes, the second printing electrodes being alternatingly spaced from the first printing electrodes in a direction parallel to the first and second rows in such a manner that each first printing electrode is spaced between two adjacent second printing electrodes and vice-versa, characterized by comprising: drive means for selectively energizing the first and second printing electrodes to form an electrostatic pattern on a printing medium disposed adjacent to the first and second printing electrodes, the drive means being constructed to energize selected first printing electrodes during a first time period and subsequently energize second printing electrodes during a second time period; and an auxiliary electrode disposed adjacent to the first and second printing electrodes, the drive means energizing the auxiliary electrode during the first and second time periods; the drive means being constructed to energize the auxiliary electrode with a first voltage during the first time period and with a second voltage which is higher than the first voltage during the second time period.
Claim 13
Dependent Claim
29 words
An apparatus as in claim 4, 5, 6, 7 or 8, in which the second row is spaced from the first row in a direction perpendicular to said direction.
Claim 14
Dependent Claim
20 words
An apparatus as in claim 4, 5, 6, 7 or 8, in which the first and second rows are colinear.
References Cited (Backward Citations)
US2997361A
Cited
US3157456A
Cited
US3624661A
Cited
US3653065A
Cited
US3797021A
Cited
US3798609A
Cited
US4157553A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-04-13 | 1984-10-13 | 1985-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-13 | 1988-10-13 | 1989-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-13 | 1992-10-13 | 1993-04-14 | $7700.00 | Window Closed / Lapsed |