Patent US5049938A successfully refreshed from Google Patents.
US5049938A
Expired / Lapsed
US
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Abnormality detecting system in an image forming apparatus
Assignee: Minolta Co Ltd
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Filing: 1990-04-10
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Granted: 1991-09-17
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Expires: 2010-04-10
Abstract
Abstract An image forming apparatus for developing an electrostatic latent image formed on the surface of a photosensitive member into a visual image by the use of two-component developer consisting of toner and carrier. The apparatus is provided with a developing unit, which accommodates the developer and in which screw rollers are rotatably mounted for agitating the developer. The apparatus is further provided with an abnormality detecting system for detecting abnormalities which are liable to occur in the developing unit. The abnormality detecting system includes a toner density sensor for detecting the density of toner accommodated in the developing unit. In the normal condition, the toner density detected by the toner density sensor regularly fluctuates as the developer accommodated in the developing unit is agitated by the screw rollers. The abnormality detecting system further includes a control circuit, in which the cycle of fluctuation of the toner density is compared with that of agitation caused by the screw rollers. When both the cycles do not coincide with each other, the control circuit outputs a signal indicating that some abnormality has occurred in the apparatus.
Inventors
- 👤 Masahide Ueda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:10
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0822; G03G15/0848; G03G15/0849; G03G15/0853; G03G15/0887; G03G15/0891; G03G15/0893
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
111 words
An image forming apparatus for developing an electrostatic latent image formed on a surface of a photosensitive member into a visual image using developer, said apparatus comprising: a developing unit accommodating the developer; agitating means for agitating the developer accommodated in said developing unit; pulsation detecting means for detecting pulsation of the developer caused by said agitating means; comparing means for comparing a cycle of the pulsation detected by said pulsation detecting means and a cycle of agitation caused by said agitating means with each other; and abnormal signal output means for outputting a signal indicative of an abnormality of the apparatus based on a result obtained by said comparing means.
Claim 2
Dependent Claim
111 words
An image forming apparatus for developing an electrostatic latent image formed on a surface of a photosensitive member into a visual image using developer, said apparatus comprising: a developing unit accommodating the developer; agitating means for agitating the developer accommodated in said developing unit; pulsation detecting means for detecting pulsation of the developer caused by said agitating means; comparing means for comparing a cycle of the pulsation detected by said pulsation detecting means and a cycle of agitation caused by said agitating means with each other; and abnormal signal output means for outputting a signal indicative of an abnormality of the apparatus based on a result obtained by said comparing means.
Claim 3
Dependent Claim
14 words
The apparatus according to claim 1, wherein the developer consists of toner and carrier.
Claim 4
Dependent Claim
23 words
The apparatus according to claim 2, wherein said pulsation detecting means comprises a permeability detecting sensor for detecting a permeability of the developer.
Claim 5
Dependent Claim
25 words
The apparatus according to claim 3, wherein said permeability detecting sensor is used to detect a density of the toner accommodated in said developing unit.
Claim 6
Dependent Claim
112 words
An image forming apparatus for developing an electrostatic latent image formed on a surface of a photosensitive member into a visual image using developer, said apparatus comprising: a developing unit accommodating the developer; agitating means for regularly agitating the developer accommodated in said developing unit; density detecting means for detecting a density of the developer accommodated in said developing unit; judging means for judging whether or not fluctuation of an output value of said density detecting means is regular, said fluctuation being caused by said agitating means; and abnormal signal output means for outputting a signal indicative of an abnormality of the apparatus based on a result obtained by said judging means.
Claim 7
Dependent Claim
112 words
An image forming apparatus for developing an electrostatic latent image formed on a surface of a photosensitive member into a visual image using developer, said apparatus comprising: a developing unit accommodating the developer; agitating means for regularly agitating the developer accommodated in said developing unit; density detecting means for detecting a density of the developer accommodated in said developing unit; judging means for judging whether or not fluctuation of an output value of said density detecting means is regular, said fluctuation being caused by said agitating means; and abnormal signal output means for outputting a signal indicative of an abnormality of the apparatus based on a result obtained by said judging means.
Claim 8
Dependent Claim
14 words
The apparatus according to claim 5, wherein the developer consists of toner and carrier.
Claim 9
Dependent Claim
23 words
The apparatus according to claim 6, wherein said density detecting means comprises a permeability detecting sensor for detecting a permeability of the developer.
Claim 10
Dependent Claim
23 words
The apparatus according to claim 5 further comprising warning means for giving a warning when said signal indicative of the abnormality is outputted.
Claim 11
Dependent Claim
26 words
The apparatus according to claim 8 further comprising stop means for stopping an operation of the apparatus when said signal indicative of the abnormality is outputted.
Claim 12
Dependent Claim
117 words
An image forming apparatus for developing an electrostatic latent image formed on a surface of a photosensitive member into a visual image using developer consisting of toner and carrier, said apparatus comprising: a developing unit accommodating the developer; agitating means for regularly agitating the developer accommodated in said developing unit; permeability detecting means for detecting a permeability of the developer accommodated in said developing unit; judging means for judging whether or not fluctuation of an output value of said permeability detecting means is regular, said fluctuation being caused by said agitating means; and abnormal signal output means for outputting a signal indicative of an abnormality of the apparatus based on a result obtained by said judging means.
Claim 13
Dependent Claim
117 words
An image forming apparatus for developing an electrostatic latent image formed on a surface of a photosensitive member into a visual image using developer consisting of toner and carrier, said apparatus comprising: a developing unit accommodating the developer; agitating means for regularly agitating the developer accommodated in said developing unit; permeability detecting means for detecting a permeability of the developer accommodated in said developing unit; judging means for judging whether or not fluctuation of an output value of said permeability detecting means is regular, said fluctuation being caused by said agitating means; and abnormal signal output means for outputting a signal indicative of an abnormality of the apparatus based on a result obtained by said judging means.
Claim 14
Dependent Claim
23 words
The apparatus according to claim 10 further comprising warning means for giving a warning when said signal indicative of the abnormality is outputted.
Claim 15
Dependent Claim
26 words
The apparatus according to claim 11 further comprising stop means for stopping an operation of the apparatus when said signal indicative of the abnormality is outputted.
Claim 16
Dependent Claim
141 words
An image forming apparatus for developing an electrostatic latent image formed on a surface of a photosensitive member into a visual image using developer consisting of toner and carrier, said apparatus comprising: a developing unit accommodating the developer; agitating means for regularly agitating the developer accommodated in said developing unit; output means for outputting a signal to be used to drive said agitating means; permeability detecting means for detecting a permeability of the developer accommodated in said developing unit; judging means for judging whether or not fluctuation of an output value of said permeability detecting means is regular when said signal for driving said agitating means is outputted, said fluctuation being caused by said agitating means; and abnormal signal output means for outputting a signal indicative of an abnormality of the apparatus based on a result obtained by said judging means.
Claim 17
Dependent Claim
141 words
An image forming apparatus for developing an electrostatic latent image formed on a surface of a photosensitive member into a visual image using developer consisting of toner and carrier, said apparatus comprising: a developing unit accommodating the developer; agitating means for regularly agitating the developer accommodated in said developing unit; output means for outputting a signal to be used to drive said agitating means; permeability detecting means for detecting a permeability of the developer accommodated in said developing unit; judging means for judging whether or not fluctuation of an output value of said permeability detecting means is regular when said signal for driving said agitating means is outputted, said fluctuation being caused by said agitating means; and abnormal signal output means for outputting a signal indicative of an abnormality of the apparatus based on a result obtained by said judging means.
Claim 18
Dependent Claim
23 words
The apparatus according to claim 13 further comprising warning means for giving a warning when said signal indicative of the abnormality is outputted.
Claim 19
Dependent Claim
188 words
An image forming apparatus for developing an electrostatic latent image formed on a surface of a photosensitive member into a visual image using developer consisting of toner and carrier, said apparatus comprising: a developing unit accommodating the developer; agitating means for regularly agitating the developer accommodated in said developing unit; a driving source for driving said agitating means; output means for outputting a signal to be used to drive said driving source; transmitting means for transmitting a driving force from said driving source to said agitating means; transmitting condition detecting means for detecting a transmitting condition of the driving force at at least one location of said transmitting means; permeability detecting means for detecting a permeability of the developer accommodated in said developing unit; fluctuation detecting means for detecting regular fluctuation of an output value of said permeability detecting means, said fluctuation being caused by said agitating means; and specifying means for specifying a location at which an abnormality has occurred based on said signal for driving said driving source, a signal outputted from said transmitting condition detecting means, and a signal outputted from said fluctuation detecting means.
Claim 20
Dependent Claim
188 words
An image forming apparatus for developing an electrostatic latent image formed on a surface of a photosensitive member into a visual image using developer consisting of toner and carrier, said apparatus comprising: a developing unit accommodating the developer; agitating means for regularly agitating the developer accommodated in said developing unit; a driving source for driving said agitating means; output means for outputting a signal to be used to drive said driving source; transmitting means for transmitting a driving force from said driving source to said agitating means; transmitting condition detecting means for detecting a transmitting condition of the driving force at at least one location of said transmitting means; permeability detecting means for detecting a permeability of the developer accommodated in said developing unit; fluctuation detecting means for detecting regular fluctuation of an output value of said permeability detecting means, said fluctuation being caused by said agitating means; and specifying means for specifying a location at which an abnormality has occurred based on said signal for driving said driving source, a signal outputted from said transmitting condition detecting means, and a signal outputted from said fluctuation detecting means.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-09-16 | 1995-03-18 | 1995-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-16 | 1999-03-18 | 1999-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-16 | 2003-03-18 | 2003-09-17 | $7700.00 | Window Closed / Lapsed |