Patent US5207014A successfully refreshed from Google Patents.
Patent EP0520144A2 successfully refreshed from Google Patents.
EP0520144A2
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EP
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Electrophotographic image forming apparatus
Assignee: Toshiba Corp
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Filing: 1992-03-20
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Granted: —
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Expires: 2012-03-20
Abstract
Abstract A toner sensor (8) measures the amount of toner attached on a photosensitive drum (1) upon development by a developing unit (4). A controller (45) compares the measured toner attaching amount with a predetermined reference value, and executes processing for changing at least one of image forming conditions, for example, the charging amount by a charger (2), the developing bias voltage of the developing unit (4), the exposure amount of an optical system (13), and the toner density of the developing unit (4), on the basis of the comparison result.
Inventors
- 👤 Rintaro c/o Intellectual Property Div. Nakane
- 👤 Jiro c/o Intellectual Property Div. Egawa
- 👤 Shigeru C/O Intellectual Property Div. Fujiwara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 16:11
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/50; G03G15/5033; G03G15/5041; G03G15/06; G03G15/08; G03G15/0822; G03G15/0848; G03G15/0849; G03G15/0855; G03G15/5037; G03G2215/00; G03G2215/00025; G03G2215/00029; G03G2215/00033; G03G2215/00037; G03G2215/00042
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
135 words
An image forming apparatus comprising: means (13, 36-38) for forming a latent image of a given pattern on an image carrier (1) in accordance with given image data, under a given forming condition (VG); means (4) for developing the latent image formed by said forming means on the image carrier (1) using a developer material (DM), under a given developing condition (VD); means (8, 45-46, 51-56) for measuring an amount (Q, QH, QL) of the developer material (DM) attached to the image carrier (1) so as to provide a measured attaching amount data (D46) of the developer material; and means (45) for controlling said forming means (13) so that at least one of given the forming condition (VG) and the given developing condition (VD) is changed in accordance with the measured attaching amount data (D46).
Claim 2
Dependent Claim
88 words
An apparatus according to claim 1, characterized in that said controlling means (45) include: means (45; ST10, ST14) for comparing the measured attaching amount data (D46) with a predetermined reference value (QHT, QLT) to provide a comparison result (ΔQH, ΔQL); means (45; ST24) for changing the given forming condition (VG) in accordance with prescribed information (VC, VBG) representing the comparison result (ΔQH, ΔQL); and means (45; ST26) for changing the given developing condition (VD) in accordance with the prescribed information (VC, VBG) and the given forming condition (VG).
Claim 3
Dependent Claim
137 words
An apparatus according to claim 1, characterized in that said controlling means (45) include: means (45; ST10, ST14) for comparing the measured attaching amount data (D46) with a predetermined reference value (QHT, QLT) to provide a comparison result (ΔQH, ΔQL); means (45; ST16, ST20) for preparing contrast information (VC) from the comparison result (ΔQH, ΔQL), so that said contrast information (VC) represents a concentration (DI) of the developer material (DM) attached to the image carrier with respect to the latent image; means (45; ST18, ST22) for preparing background potential information (VBG) from the comparison result (ΔQH, ΔQL), said background potential information (VBG) corresponding to a surface potential (VO) of said image carrier (1); and means (45; ST24) for changing the given forming condition (VG) in accordance with the contract information (VC) and the background potential information (VBG).
Claim 4
Dependent Claim
39 words
An apparatus according to claim 3, characterized in that said controlling means (45) further includes: means (45; ST26) for changing the given developing condition (VD) in accordance with the given forming condition (VG) and the background potential information (VBG).
Claim 5
Independent Claim
79 words
An apparatus according to claim, 1 characterized in that said measuring means (8, 45-46, 51-56) includes: means (51, 54) for supplying light to a surface of said image carrier (1) with a prescribed incident angle (ϑ) with respect to a normal line of the image carrier surface; means (52-56, 46) for detecting the light (L1, L2) supplied from said supplying means (51) and reflected at the image carrier surface, so as to generate said measured attaching amount data (D46).
Claim 6
Dependent Claim
110 words
An apparatus according to claim 5, characterized in that said supplying means (51, 54) includes a light source (51) for generating the light having such a wave length that the light is scattered or absorbed by the developer material (DM) on said image carrier (1), and said detecting means (52-56, 46) includes: a photo sensor (52, 55), having a sensitivity at the wave length of the light generated by said light source (51), for sensing the light coming from the surface of said image carrier (1) to provide a sensed signal (E52, E55); and means (46) for converting the sensed signal (E52, E55) into the measured attaching amount data (D46).
Claim 7
Dependent Claim
154 words
An apparatus according to claim 5, characterized in that said supplying means (51, 54) includes a light source (51) for generating the light having such a wave length that the light is scattered or absorbed by the developer material (DM) on said image carrier (1), and said detecting means (52-56, 46) includes: a first photo sensor (52), having a sensitivity at the wave length of the light generated by said light source (51), for sensing the light reflected from the surface of said image carrier (1) to provide a first sensed signal (E52); a second photo sensor (55), having a sensitivity at the wave length of the light generated by said light source (51), for sensing the light scattered at the surface of said image carrier (1) to provide a second sensed signal (E55); and means (46) for converting the first and second sensed signals (E52, E55) into the measured attaching amount data (D46).
Claim 8
Dependent Claim
59 words
An apparatus according to claim 1, characterized in that said forming means (13, 36-38) includes: means for forming a latent image of a test pattern at a specific region (lR2) of the image carrier (1), said specific region (lR2) being outside of an imaging region (lR1) of the image carrier (1), and said test pattern containing predetermined gradation information.
References Cited (Backward Citations)
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