Patent EP0258060A2 successfully refreshed from Google Patents.
EP0258060A2
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EP
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Light quantity control device
Assignee: Canon Inc
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Filing: 1987-08-27
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Granted: —
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Expires: 2007-08-27
Abstract
Abstract The light quantity control device is suitable for use in a laser beam printer. A controller (ll0, l02, l03, l04, l05, l06) regulates the quantity of light emitted by a semiconductor laser (l08) so as to maintain a constant light quantity. The regulation of the light quantity is according to the output of a monitor (l09) for detecting the light quantity from the semiconductor laser (l08).
Inventors
- 👤 Toshihiko Inuyama
- 👤 Junichi Kimizuka
- 👤 Akihisa Kusano
- 👤 Takashi No. 102 Soya
- 👤 Kaoru Sata
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 16:30
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/06; H01S5/068; H01S5/0683; G; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1204; G06K15/1209; G06K15/1214; H01S5/04; H01S5/042; H01S5/0617; H01S5/06812; H01S5/06832
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
104 words
A light quantity control device comprising: beam generating means; monitor means for monitoring the light quantity of a beam generated by said beam generating means; and control means for controlling the light quantity of the beam generated by said beam generating means in response to the output of said monitor means; wherein said control means is adapted to vary the light quantity of said beam generated by said beam generating means so as to obtain a constant light quantity, and to vary the rate of said variation in the light quantity of said beam on the basis of the output of said monitor means.
Claim 2
Dependent Claim
104 words
A light quantity control device comprising: beam generating means; monitor means for monitoring the light quantity of a beam generated by said beam generating means; and control means for controlling the light quantity of the beam generated by said beam generating means in response to the output of said monitor means; wherein said control means is adapted to vary the light quantity of said beam generated by said beam generating means so as to obtain a constant light quantity, and to vary the rate of said variation in the light quantity of said beam on the basis of the output of said monitor means.
Claim 3
Dependent Claim
27 words
A light quantity control device according to Claim l, wherein said monitor means is adapted to detect the light quantity of said beam as a monitor voltage.
Claim 4
Dependent Claim
65 words
A light quantity control device according to Claim 2, wherein said control means comprises counter means for effecting a counting operation; a D/A converter means for effecting D/A conversion of the digital count supplied from said counter means; and a drive current control circuit for controlling the drive current for said beam generating means on the basis of the output of said D/A converter means.
Claim 5
Dependent Claim
18 words
A light quantity control device according to Claim l, wherein said beam generating means comprises a semiconductor laser.
Claim 6
Dependent Claim
118 words
A light quantity control device comprising: beam generating means; monitor means for monitoring the light quantity of the beam generated by said beam generating means; and control means for controlling the light quantity of the beam generated by said beam generating means on the basis of the output from said monitor means; wherein said control means comprises discrimination means for discriminating whether the output of said monitor means is at a predetermined level; and bias current determining means for determining a predetermined proportion of the current supplied to said beam generating means as the bias current for said beam generating means when said discrimination means discriminates that the output of said monitor means is at said predetermined level.
Claim 7
Dependent Claim
118 words
A light quantity control device comprising: beam generating means; monitor means for monitoring the light quantity of the beam generated by said beam generating means; and control means for controlling the light quantity of the beam generated by said beam generating means on the basis of the output from said monitor means; wherein said control means comprises discrimination means for discriminating whether the output of said monitor means is at a predetermined level; and bias current determining means for determining a predetermined proportion of the current supplied to said beam generating means as the bias current for said beam generating means when said discrimination means discriminates that the output of said monitor means is at said predetermined level.
Claim 8
Dependent Claim
27 words
A light quantity control device according to Claim 5, wherein said monitor means is adapted to detect the light quantity of said beam as a monitor voltage.
Claim 9
Dependent Claim
36 words
A light quantity control device according to Claim 5, wherein said control means is adapted to determine said bias current, and thereafter to determine a drive current for causing beam emission from said beam generating means.
Claim 10
Dependent Claim
60 words
A light quantity control device comprising; beam generating means; recording means for recording information, by utilizing a beam generated by said beam generating means; and control means for controlling the drive current for said beam generating means; wherein said control means is adapted to sufficiently reduce said drive current in association with the state that said recording means is disenabled.
Claim 11
Dependent Claim
60 words
A light quantity control device comprising; beam generating means; recording means for recording information, by utilizing a beam generated by said beam generating means; and control means for controlling the drive current for said beam generating means; wherein said control means is adapted to sufficiently reduce said drive current in association with the state that said recording means is disenabled.
Claim 12
Dependent Claim
53 words
A light quantity control device according to Claim 8, wherein said drive current comprises a bias current for said beam generating means and a light emission current for causing the beam generation, and said control means is adapted to sufficiently reduce at least one of said bias current and said light emission current.
Claim 13
Dependent Claim
81 words
l0. A light quantity control device comprising: beam generating means; monitor means for monitoring the light quantity of a beam generated by said beam generating means; and control means for controlling the light quantity of said beam generated by said beam generating means in response to the output of said monitor means; wherein said control means is adapted to sufficiently reduce said drive current when it is discriminated that the output of said monitor means is not within a predetermined range.
Claim 14
Dependent Claim
81 words
l0. A light quantity control device comprising: beam generating means; monitor means for monitoring the light quantity of a beam generated by said beam generating means; and control means for controlling the light quantity of said beam generated by said beam generating means in response to the output of said monitor means; wherein said control means is adapted to sufficiently reduce said drive current when it is discriminated that the output of said monitor means is not within a predetermined range.
Claim 15
Dependent Claim
93 words
Apparatus for controlling the emission of radiation from a radiation emitter (l08), comprising: means (l09) for detectiang radiation from the emitter (l08), Means (ll0, l02, l03, l04) responsive to the detecting means for setting a bias level of energisation of the emitter at a predetermined level (I bt ) less than the level (I b0 ) at which minimal emission takes place, and means (ll0, l02, l05, l06) responsive to the detecting means for setting an active level (I s ) of energisation of the emitter at which a predetermined emission takes place.
Claim 16
Dependent Claim
93 words
Apparatus for controlling the emission of radiation from a radiation emitter (l08), comprising: means (l09) for detectiang radiation from the emitter (l08), Means (ll0, l02, l03, l04) responsive to the detecting means for setting a bias level of energisation of the emitter at a predetermined level (I bt ) less than the level (I b0 ) at which minimal emission takes place, and means (ll0, l02, l05, l06) responsive to the detecting means for setting an active level (I s ) of energisation of the emitter at which a predetermined emission takes place.
Claim 17
Dependent Claim
26 words
Apparatus according to claim ll, further comprising means (l0l, l2l, l22, l07) for controllably selecting the said bias level and the said active level of energisation.
Claim 18
Dependent Claim
36 words
Apparatus for controlling the emission of radiation from a radiation emitter, comprising; means (l09) for detecting radiation from the emitter, and means (ll0, l02 to l06) responsive to the detecting means to control the emitter (l08).
Claim 19
Dependent Claim
36 words
Apparatus for controlling the emission of radiation from a radiation emitter, comprising; means (l09) for detecting radiation from the emitter, and means (ll0, l02 to l06) responsive to the detecting means to control the emitter (l08).
References Cited (Backward Citations)
No citation records indexed.
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