US4256402A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus of detecting toner concentration of dry developer
Assignee: Olympus Corp
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Filing: 1978-08-23
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Granted: 1981-03-17
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Expires: 1998-08-23
Abstract
Abstract A method and apparatus to detect the toner concentration of two component dry developer comprising toner and carrier includes the use of a toner catcher having a conductive member and which is capacitively charged. The developer is applied to the catcher, which traps the toner to determine the toner content.
Inventors
- 👤 Masaji Nishikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:29
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0822; G03G15/0848; G03G15/0849; G03G15/0855
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
98 words
In a toner concentration determining apparatus including an electrically chargeable conductive member which, when charged, attracts toner from dry developer, including said toner and carrier, the improvement comprising at least one capacitor, means for charging said capacitor with a predetermined quantity of electric charge, means for transferring said predetermined quantity of electric charge of said capacitor to said conductive member, the predetermined quantity of electric charge of said conductive member having a magnitude and polarity selected such that said charged conductive member attracts said toner from said dry developer in an amount representative ot the toner concentration thereof.
Claim 2
Dependent Claim
98 words
In a toner concentration determining apparatus including an electrically chargeable conductive member which, when charged, attracts toner from dry developer, including said toner and carrier, the improvement comprising at least one capacitor, means for charging said capacitor with a predetermined quantity of electric charge, means for transferring said predetermined quantity of electric charge of said capacitor to said conductive member, the predetermined quantity of electric charge of said conductive member having a magnitude and polarity selected such that said charged conductive member attracts said toner from said dry developer in an amount representative ot the toner concentration thereof.
Claim 3
Dependent Claim
29 words
An apparatus according to claim 1 in which the conductive member comprises a conductive base, an electrically insulating layer and a conductive surface layer which are sequentially laminated together.
Claim 4
Dependent Claim
54 words
An apparatus according to claim 1 in which the conductive member comprises a conductive roller, an electrically insulating layer laminated on the outer periphery of the conductive roller, and a conductive surface layer laminated on the insulating layer, the conductive member being driven for rotation in a given direction and at a uniform rate.
Claim 5
Dependent Claim
69 words
An apparatus according to claim 1 in which the conductive member comprises a conductive roller, an array of electrically insulating layers and grounded conductive layers on the roller which are arranged in alternating fashion about the circumference of the roller, the grounded layers being maintained at ground potential to provide a correction of a fogging density, and a plurality of conductive surface layers on each of the insulating layers.
Claim 6
Dependent Claim
39 words
An apparatus according to claim 1, further comprising means for determining the amount of toner attracted to the conductive member, the determining means including an optical density detector having a light source, a lens system and a light receiver.
Claim 7
Dependent Claim
82 words
The apparatus of claim 1, further comprising a receptacle for containing dry developer from which dry developer is conveyed to the conductive member ; means for determining the amount of toner attracted to the conductive member, said amount of toner corresponding to the toner concentration of the developer; a supply source of fresh dry developer and means responsive to said determining means for dispensing fresh dry developer from said supply source into said receptacle when said concentration falls below a predetermined level.
Claim 8
Dependent Claim
58 words
An apparatus according to claim 1, in which the conductive member is mounted at a free end of a rockable arm , the conductive member having an arcuate surface, an electrically insulating layer and a conductive surface layer, the electrically insulating layer and the conductive surface layer being respectively laminated on the arcuate surface of the conductive member.
Claim 9
Dependent Claim
35 words
An apparatus according to claim 7 which the conductive member is movable between a first position where the toner is attracted thereto and a second position where the amount of the attracted toner is determined.
Claim 10
Dependent Claim
51 words
An apparatus according to claim 1, in which the means for charging said capacitor includes a d.c. source, the conductive member comprising a conductive base, an electrically insulating layer and a conductive surface layer, the source being connected between the conductive base and the surface layer to charge the insulating layer.
Claim 11
Dependent Claim
29 words
An apparatus according to claim 8 in which the capacitance of the conductive member is adjusted by connecting an additional capacitor between the conductive base and the surface layer.
Claim 12
Dependent Claim
30 words
An apparatus according to claim 9 in which the d.c. source is connected between the conductive base and the surface layer through a power switch and a polarity reversal switch.
Claim 13
Dependent Claim
57 words
An apparatus according to claim 1, further comprising a magnetic roller which is disposed within a vessel which contains the developer, the magnetic roller being located in close proximity to the conductive member whereby the conductive member attracts said toner from the magnetic roller which carries the dry developer and also supplies it to a developing drum.
Claim 14
Dependent Claim
85 words
In a method of determining the toner concentration of dry developer, including toner and carrier, by electrically charging a conductive member so as to attract toner from dry developer, the improvement comprising the steps of charging a capacitor with a predetermined quantity of electric charge, transferring the charge of said capacitor to said conductive member, selecting the magnitude and polarity of said charge such that said charged conductive member attracts said toner from said dry developer in an amount representative of the toner concentration thereof.
Claim 15
Dependent Claim
85 words
In a method of determining the toner concentration of dry developer, including toner and carrier, by electrically charging a conductive member so as to attract toner from dry developer, the improvement comprising the steps of charging a capacitor with a predetermined quantity of electric charge, transferring the charge of said capacitor to said conductive member, selecting the magnitude and polarity of said charge such that said charged conductive member attracts said toner from said dry developer in an amount representative of the toner concentration thereof.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |