US3756192A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic toner concentration control system
Assignee: International Business Machines Corp
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Filing: 1971-12-17
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Granted: 1973-09-04
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Expires: 1991-12-17
Abstract
Abstract A toner concentration control system for an electrostatic copier wherein light is alternately reflected from multicomponent developer material containing toner and from a calibrated reflector to a photosensor. An imbalance of toner in the developer material results in a difference in reflected light intensity from the developer and reflector which is converted into an electrical signal having an AC component. A phase sensing circuit detects the position of the peak of the AC signal component with reference to the position of the calibrated reflector and provides a control signal to a toner replenishing device. Developer flow past the photosensor is intermittently halted during concentration sensing to reduce noise effects. A plurality of selectable calibrated reflectors provide different concentration settings. Additional concentration settings are obtained by varying the light spectrum emitted by the light source.
Inventors
- 👤 H Locklar
- 👤 D Tao
- 👤 L Tarver
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:02
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0822; G03G15/0848; G03G15/0849; G03G15/0855; G03G15/0887; G03G15/0891; Y; Y10; Y10S; Y10S222/00; Y10S222/01
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
188 words
Apparatus for controlling the concentration of multicomponent developer material including toner for use in an electrostatic reproduction apparatus including: actuatable means for dispensing toner into the developer material; a light source; a developer unit fixedly mounted and having a viewing window for presenting developer material illuminated by said light source; at least one calibrated light reflector movable from a first position to a second position, said light reflector being illuminated by said light source when in said second position; photosensing means alternately responsive to light reflected from said illuminated developer material presented by said viewing window and to light reflected from said light reflector when said light reflector is in said second position for converting light into an electrical signal having an AC component when the intensity of light from the light reflector differs from the intensity of light from the developer material, said light reflector being interposed between said viewing window and said photosensing means when in said second position for preventing light from said developer material from striking said photosensing means; control means responsive to said electrical signal for actuating said actuatable means for dispensing toner.
Claim 2
Dependent Claim
188 words
Apparatus for controlling the concentration of multicomponent developer material including toner for use in an electrostatic reproduction apparatus including: actuatable means for dispensing toner into the developer material; a light source; a developer unit fixedly mounted and having a viewing window for presenting developer material illuminated by said light source; at least one calibrated light reflector movable from a first position to a second position, said light reflector being illuminated by said light source when in said second position; photosensing means alternately responsive to light reflected from said illuminated developer material presented by said viewing window and to light reflected from said light reflector when said light reflector is in said second position for converting light into an electrical signal having an AC component when the intensity of light from the light reflector differs from the intensity of light from the developer material, said light reflector being interposed between said viewing window and said photosensing means when in said second position for preventing light from said developer material from striking said photosensing means; control means responsive to said electrical signal for actuating said actuatable means for dispensing toner.
Claim 3
Dependent Claim
66 words
The toner concentration control system set forth in claim 1 further comprising means for effecting motion of said developer material past the viewing window; actuatable halting means for halting the motion of said developer material at the viewing window; means for actuating said halting means and for providing a halting signal; said control means being further responsive to the halting signal for actuating said actuatable means.
Claim 4
Dependent Claim
62 words
The toner concentration control system set forth in claim 1 wherein said calibrated light reflector reflects light of an intensity equal to that reflected by a desired developer material concentration and wherein said control means being responsive whenever the intensity of the reflected light from the light modifying means is greater than the intensity of the reflected light from the developer material.
Claim 5
Dependent Claim
78 words
The apparatus for controlling the concentration of multicomponent developer material set forth in claim 8 comprising a plurality of calibrated light reflectors having differing light reflectance characteristics; selection means for selecting one of said plurality of light reflectors; motion means for moving said selected one of said light reflectors to said second position; and wherein said photosensing means is responsive to light reflected from said selected light reflector when said selected light reflector is in said second position.
Claim 6
Dependent Claim
47 words
The apparatus for controlling the concentration of multicomponent developer material set forth in claim 9 wherein said plurality of light reflectors are mounted on a rotary means and wherein said motion means effects rotation of said rotary means thereby presenting each light reflector at said second position.
Claim 7
Dependent Claim
85 words
Apparatus for controlling the concentration of multicomponent developer material set forth in claim 8 further comprising: means for varying the light spectrum of said light source by a controlled amount; said viewing window having a nonuniform light transmission spectrum; said photosensing means being responsive to reflected light to provide an output signal, the magnitude of which is dependent on the spectrum of light incident thereon; and wherein said control means being responsive to a predetermined magnitude of said electrical signal for actuating said actuatable means.
Claim 8
Dependent Claim
65 words
Apparatus for controlling the concentration of multicomponent developer material set forth in claim 8 further comprising: phase signal generating means for generating a phase signal identifying the position of the light reflector; said control means being further responsive to said phase signal for actuating said actuatable means when the intensity of the light from the light reflector is less than that from the developer material.
Claim 9
Dependent Claim
55 words
Apparatus for controlling the concentration of multicomponent developer material set forth in claim 7 wherein said control means being responsive to a predetermined magnitude of said electrical signal in phase with said phase signal for actuating said actuable means and responsive to a second predetermined magnitude of said electrical signal to deactuate said actuable means.
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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) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |