US5315353A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image recording method including determining a gap between a photosensitive medium and a developing roller and apparatus therefor
Assignee: Koki Holdings Co Ltd
•
Filing: 1992-09-25
•
Granted: 1994-05-24
•
Expires: 2012-09-25
Abstract
Abstract An image recording apparatus including a photosensitive medium. A voltage is applied between the photosensitive medium and a developing sleeve of a developing unit, and a current flowing between the photosensitive medium and the developing sleeve is measured to be converted into a pulse waveform which is then compared by a predetermined reference value. On the basis of the result of the comparison, a gap is determined between the photosensitive medium and the developing unit, which is then advanced or retracted toward or from the photosensitive medium in accordance with the determined gap. Owing to the recording method carried out by the image recording apparatus, the gap can be selectively determined by observing the current waveform pattern of the current flowing between the photosensitive medium and the developing sleeve while decreasing gradually the gap therebetween, whereby a relation between the gap and height of a magnetic brush can definitely be established. Since the gap can be set within a range from a value representing an initial contact state in which the magnetic brush starts to contact with the photosensitive medium to a value representing a wholly contact state in which the whole magnetic brush contacts with the photosensitive medium with the aid of a current curve of the current flowing between the photosensitive medium and the developing sleeve, a contacting force of the magnetic brush bearing on the photosensitive medium can be weakened.
Inventors
- 👤 Yuzuru Simazaki
- 👤 Takao Kumasaka
- 👤 Kunio Satoh
- 👤 Youji Hirose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:37
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/01; G03G15/0105; G03G15/0126
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
229 words
An image recording method of forming a magnetic brush of a two-component developer on each of developing rollers provided in a plurality of developing units, respectively, forming a toner image of a first color on a recording area of photosensitive medium by a first one of said plural developing units and then forming a toner image of another color on the recording area of said photosensitive medium by a succeeding developing unit through contact of said magnetic brush with said photosensitive medium during a single rotation of said photosensitive medium, comprising the steps of: a) applying a predetermined voltage between said photosensitive medium and a developing roller of at least one of said plural developing units; b) measuring a current flowing between said photosensitive medium and said developing roller upon application of said predetermined voltage; and c) determining the current flowing between said photosensitive medium and said developing roller in a range from a value representing an initial contact state in which only a tip end portion of said magnetic brush is brought into contact with said photosensitive medium to a value representing a wholly contact state in which said magnetic brush contacts substantially wholly with said photosensitive medium by changing a degree of the contact of said magnetic brush with said photosensitive medium, and selecting a gap between said photosensitive medium and said developing roller within said range.
Claim 2
Dependent Claim
229 words
An image recording method of forming a magnetic brush of a two-component developer on each of developing rollers provided in a plurality of developing units, respectively, forming a toner image of a first color on a recording area of photosensitive medium by a first one of said plural developing units and then forming a toner image of another color on the recording area of said photosensitive medium by a succeeding developing unit through contact of said magnetic brush with said photosensitive medium during a single rotation of said photosensitive medium, comprising the steps of: a) applying a predetermined voltage between said photosensitive medium and a developing roller of at least one of said plural developing units; b) measuring a current flowing between said photosensitive medium and said developing roller upon application of said predetermined voltage; and c) determining the current flowing between said photosensitive medium and said developing roller in a range from a value representing an initial contact state in which only a tip end portion of said magnetic brush is brought into contact with said photosensitive medium to a value representing a wholly contact state in which said magnetic brush contacts substantially wholly with said photosensitive medium by changing a degree of the contact of said magnetic brush with said photosensitive medium, and selecting a gap between said photosensitive medium and said developing roller within said range.
Claim 3
Dependent Claim
45 words
An image recording method according to claim 1, wherein the step of applying the predetermined voltage includes a sub-step of selecting a voltage of such magnitude that no electric discharge can take place between said photosensitive medium and said developing roller, as the predetermined voltage.
Claim 4
Dependent Claim
35 words
An image recording method according to claim 1, wherein the step of applying the predetermined voltage includes a sub-step of selecting a voltage in a range of 1 to 250 volts, as the predetermined voltage.
Claim 5
Dependent Claim
34 words
An image recording medium according to claim 1, including the further step of selecting said two-component developer used for forming said magnetic brush, said two-component developer containing a toner and a resin binding carrier.
Claim 6
Dependent Claim
45 words
An image recording method according to claim 1, including the further step of selecting said two-component developer used for forming said magnetic brush, said two-component developer containing a toner and a resin binding carrier, wherein said resin binding carrier is formed of a semiconductive material.
Claim 7
Dependent Claim
55 words
An image recording method according to claim 1, including the further step of selecting said two-component developer used for forming said magnetic brush, said two-component developer containing a magnetic toner and a resin binding carrier, wherein a proportion of said magnetic toner relative to a total amount of said resin binding carrier is over 70%.
Claim 8
Dependent Claim
213 words
An image recording method of forming a magnetic brush of a two-component developer on each of developing rollers provided in a plurality of developing units, respectively, forming a toner image of a first color on a recording area of photosensitive medium by a first one of said plural developing units and then forming a toner image of another color on the recording area of said photosensitive medium by a succeeding developing unit through contact of said magnetic brush with said photosensitive medium during a single rotation of said photosensitive medium, comprising the steps of: a) setting a waveform pattern of a current flowing between said photosensitive medium and a developing roller on the basis of a predetermined degree of contact of said magnetic brush with said photosensitive medium; b) applying a predetermined voltage between said photosensitive medium and the developing roller of at least one of said plural developing units; c) measuring a current flowing between said photosensitive medium and said developing roller upon application of said voltage; and d) selecting a gap between said photosensitive medium and said developing roller on the basis of magnitude of said current measured and a current waveform pattern representing degree of contact of said magnetic brush with said photosensitive medium while changing said degree of contact.
Claim 9
Dependent Claim
213 words
An image recording method of forming a magnetic brush of a two-component developer on each of developing rollers provided in a plurality of developing units, respectively, forming a toner image of a first color on a recording area of photosensitive medium by a first one of said plural developing units and then forming a toner image of another color on the recording area of said photosensitive medium by a succeeding developing unit through contact of said magnetic brush with said photosensitive medium during a single rotation of said photosensitive medium, comprising the steps of: a) setting a waveform pattern of a current flowing between said photosensitive medium and a developing roller on the basis of a predetermined degree of contact of said magnetic brush with said photosensitive medium; b) applying a predetermined voltage between said photosensitive medium and the developing roller of at least one of said plural developing units; c) measuring a current flowing between said photosensitive medium and said developing roller upon application of said voltage; and d) selecting a gap between said photosensitive medium and said developing roller on the basis of magnitude of said current measured and a current waveform pattern representing degree of contact of said magnetic brush with said photosensitive medium while changing said degree of contact.
Claim 10
Dependent Claim
259 words
An image recording method of forming a magnetic brush of a two-component developer on each of developing rollers provided in a plurality of developing units, respectively, forming a toner image of a first color on a recording area of photosensitive medium by a first developing unit and then forming a toner image of another color on the recording area of said photosensitive medium by a succeeding developing unit through contact of said magnetic brush with said photosensitive medium during a single rotation of said photosensitive medium, comprising the steps of: a) setting a waveform pattern of a current flowing between said photosensitive medium and a developing roller on the basis of a predetermined degree of contact of said magnetic brush with said photosensitive medium; b) moving the developing roller of said developing unit away from said photosensitive medium to such an extent that said magnetic brush does not contact with said photosensitive medium; c) applying a predetermined voltage between said photosensitive medium and the developing roller of at least one of said plural developing units; and d) decreasing progressively a gap between said photosensitive medium and said developing roller in the state where said voltage is applied, monitoring magnitude of said current flowing between said photosensitive medium and said developing roller as well as said current waveform pattern, said current and said current waveform pattern changing as said gap decreases, and selecting the gap between said photosensitive medium and said developing roller so that a current waveform pattern as monitored coincides at least approximately with said predetermined waveform pattern.
Claim 11
Dependent Claim
259 words
An image recording method of forming a magnetic brush of a two-component developer on each of developing rollers provided in a plurality of developing units, respectively, forming a toner image of a first color on a recording area of photosensitive medium by a first developing unit and then forming a toner image of another color on the recording area of said photosensitive medium by a succeeding developing unit through contact of said magnetic brush with said photosensitive medium during a single rotation of said photosensitive medium, comprising the steps of: a) setting a waveform pattern of a current flowing between said photosensitive medium and a developing roller on the basis of a predetermined degree of contact of said magnetic brush with said photosensitive medium; b) moving the developing roller of said developing unit away from said photosensitive medium to such an extent that said magnetic brush does not contact with said photosensitive medium; c) applying a predetermined voltage between said photosensitive medium and the developing roller of at least one of said plural developing units; and d) decreasing progressively a gap between said photosensitive medium and said developing roller in the state where said voltage is applied, monitoring magnitude of said current flowing between said photosensitive medium and said developing roller as well as said current waveform pattern, said current and said current waveform pattern changing as said gap decreases, and selecting the gap between said photosensitive medium and said developing roller so that a current waveform pattern as monitored coincides at least approximately with said predetermined waveform pattern.
Claim 12
Dependent Claim
245 words
An image recording method of forming a magnetic brush of a two-component developer on each of developing rollers provided in a plurality of developing units, respectively, forming a toner image of a first color on a recording area of photosensitive medium by a first developing unit and then forming a toner image of another color on the recording area of said photosensitive medium by a succeeding developing brush unit through contact of said magnetic brush with said photosensitive medium during a single rotation of said photosensitive medium, comprising the steps of: a) mounting a metallic drum having an electric resistance of substantially zero as said photosensitive medium; b) setting a waveform pattern of a current flowing between said metallic drum and a developing roller on the basis of a degree of contact of said magnetic brush with said metallic drum; c) applying a predetermined voltage between said metallic drum and the developing roller of at least one of said plural developing units; d) measuring a current flowing between said metallic drum and said developing roller upon application of said voltage; e) setting a gap between said metallic drum and said developing roller on the basis of magnitude of the current flowing between said metallic drum and said developing roller as well as said current waveform pattern representing the degree of contact of said magnetic brush with said metallic drum; and f) replacing said metallic drum by a semiconductive photosensitive medium after setting of said gap.
Claim 13
Dependent Claim
245 words
An image recording method of forming a magnetic brush of a two-component developer on each of developing rollers provided in a plurality of developing units, respectively, forming a toner image of a first color on a recording area of photosensitive medium by a first developing unit and then forming a toner image of another color on the recording area of said photosensitive medium by a succeeding developing brush unit through contact of said magnetic brush with said photosensitive medium during a single rotation of said photosensitive medium, comprising the steps of: a) mounting a metallic drum having an electric resistance of substantially zero as said photosensitive medium; b) setting a waveform pattern of a current flowing between said metallic drum and a developing roller on the basis of a degree of contact of said magnetic brush with said metallic drum; c) applying a predetermined voltage between said metallic drum and the developing roller of at least one of said plural developing units; d) measuring a current flowing between said metallic drum and said developing roller upon application of said voltage; e) setting a gap between said metallic drum and said developing roller on the basis of magnitude of the current flowing between said metallic drum and said developing roller as well as said current waveform pattern representing the degree of contact of said magnetic brush with said metallic drum; and f) replacing said metallic drum by a semiconductive photosensitive medium after setting of said gap.
Claim 14
Dependent Claim
250 words
An image recording apparatus for forming a magnetic brush of a two-component developer on each of developing rollers provided in a plurality of developing units, respectively, forming a toner image of a first color on a recording area of photosensitive medium by a first developing unit and then forming a toner image of another color on the recording area of said photosensitive medium by a succeeding developing unit through contact of said magnetic brush with said photosensitive medium during a single rotation of said photosensitive medium, comprising: a) said photosensitive medium having a recording area on an outer surface thereof in which a toner image is formed in the course of rotation of said photosensitive medium; b) a power supply source for applying a predetermined voltage between said photosensitive medium and a developing roller of at least one of said plural developing units; c) a monitoring unit for measuring a current flowing between said photosensitive medium and said developing roller, converting the measured current into a pulse waveform and comparing said pulse waveform with a predetermined reference pulse waveform; d) a selecting unit for selectively determining a gap between said photosensitive medium and the developing roller of said at least one developing unit on the basis of result of the comparison available from output of said monitoring unit; and e) a moving unit for advancing or retracting said at least one developing unit toward or from said photosensitive medium on the basis of the gap determined by said selecting unit.
Claim 15
Dependent Claim
250 words
An image recording apparatus for forming a magnetic brush of a two-component developer on each of developing rollers provided in a plurality of developing units, respectively, forming a toner image of a first color on a recording area of photosensitive medium by a first developing unit and then forming a toner image of another color on the recording area of said photosensitive medium by a succeeding developing unit through contact of said magnetic brush with said photosensitive medium during a single rotation of said photosensitive medium, comprising: a) said photosensitive medium having a recording area on an outer surface thereof in which a toner image is formed in the course of rotation of said photosensitive medium; b) a power supply source for applying a predetermined voltage between said photosensitive medium and a developing roller of at least one of said plural developing units; c) a monitoring unit for measuring a current flowing between said photosensitive medium and said developing roller, converting the measured current into a pulse waveform and comparing said pulse waveform with a predetermined reference pulse waveform; d) a selecting unit for selectively determining a gap between said photosensitive medium and the developing roller of said at least one developing unit on the basis of result of the comparison available from output of said monitoring unit; and e) a moving unit for advancing or retracting said at least one developing unit toward or from said photosensitive medium on the basis of the gap determined by said selecting unit.
Claim 16
Dependent Claim
17 words
An image recording apparatus according to claim 10, wherein said photosensitive medium includes a semiconductive photosensitive medium.
Claim 17
Dependent Claim
30 words
An image recording apparatus according to claim 11, wherein said moving unit includes an eccentricity absorbing unit for accommodating eccentricity of said photosensitive medium possibly taking place during rotation thereof.
Claim 18
Dependent Claim
59 words
An image recording apparatus according to claim 12, wherein said eccentricity absorbing unit includes a guide rail, a rail moving on and along said guide rail while supporting said developing unit, a motor for driving said rail, and a database storing data concerning positional deviations for commanding said motor to revolve said photosensitive medium in accordance with eccentricity thereof.
Claim 19
Dependent Claim
33 words
An image recording apparatus according to claim 11, wherein said monitoring unit includes a resistance decreasing unit for decreasing electric resistance of an insulation layer forming the outer surface of said photosensitive medium.
Claim 20
Dependent Claim
109 words
An image recording apparatus according to claim 11, wherein said selecting unit includes a first comparator which operates when the number of the pulses outputted from said counter is smaller than a reference value, an advancing power supply source for commanding said moving unit to move said developing roller toward said photosensitive medium in response to operation of said first comparator; a second comparator which operates when the number of pulses outputted from said counter is greater than a predetermined value, and a retracting power supply source for commanding said moving unit to retract said developing roller from said photosensitive medium in response to operation of said second comparator.
Claim 21
Dependent Claim
48 words
An image recording apparatus according to claim 10, wherein said monitoring unit includes a resistance adjusting unit for lowering the electric resistance of the two-component developer contained within said developing unit to within a standard range when said electric resistance is higher than a reference electric resistance value.
Claim 22
Dependent Claim
91 words
An image recording apparatus according to claim 16, wherein said resistance adjusting unit includes a container containing electrically conductive magnetic particles, measuring structure for measuring the electric resistance of the two-component developer accommodated within said developing unit, and supply structure for admixing said electrically conductive magnetic particles to the developer accommodated within said developing unit from said container to thereby lower the electric resistance of said developer to within a standard resistance range when the electric resistance of said two-component developer is detected to be higher than the reference resistance value.
Claim 23
Dependent Claim
69 words
An image recording apparatus according to claim 10, wherein said monitoring unit includes at least a current-to-voltage converter for converting the current flowing between said photosensitive medium and said developing roller, a reference voltage generator for generating a reference voltage for the voltage generated by said current-to-voltage converter, a voltage comparator for comparing said voltage with said reference voltage, and a counter for counting pulses outputted from said comparator.
References Cited (Backward Citations)
US4194466A
Cited
US4434221A
Cited
US4466732A
Cited
US4797335A
Cited
US5025288A
Cited
US5168027A
Cited
US5187523A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-05-23 | 1997-11-22 | 1998-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-23 | 2001-11-22 | 2002-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-23 | 2005-11-22 | 2006-05-24 | $7700.00 | Window Closed / Lapsed |