Patent EP0165060A2 successfully refreshed from Google Patents.
EP0165060A2
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EP
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Semiconductor laser beam scanning device
Assignee: Fujifilm Holdings Corp
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Filing: 1985-06-12
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Granted: —
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Expires: 2005-06-12
Abstract
Abstract A semiconductor laser beam scanning device includes a plurality of semiconductor lasers (11, 12, 13, 14) for emitting respective primary laser beams (41, 42, 43, 44) which are combined into a single laser beam (45) to scan a desired surface (7). The power of the combined laser beam (45) is detected by a laser beam energy detector (52) which applies a laser beam energy signal (P) to a laser drive/control circuit (51). Alternatively, the laser beam energy signal (P) is applied to a comparator (46) which compares the laser beam energy signal with a reference signal (Sr) and issues a difference signal (H/L) to a control circuit (56) connected to a laser drive circuit (55). The laser drive/control circuit (51) for the control circuit (56) is responsive to the applied signal for controllably energizing at least one (14) of the semiconductor lasers to control the power of the laser beam (44) emitted therefrom thereby to keep the power of the combined laser beam (45) at a constant level. The laser beam energy detector (52) may be disposed adjacent to the surface (7) to be scanned for detecting the power of the combined laser beam in each scanning cycle, or may detect a laser beam (87a) divided from the combined laser beam (87) by a beam splitter (92) disposed on a beam path for the combined laser beam.
Inventors
- 👤 Kazuo Horikawa
- 👤 Hideo Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 20:05
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40025; H04N1/4005; G; G02; G02B; G02B26/00; G02B26/08; G02B26/10; G02B26/12; G02B26/123; H01; H01S; H01S5/00; H01S5/40; H01S5/4025; H04N1/40037; H01S5/06; H01S5/068; H01S5/0683
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
118 words
A semiconductor laser beam scanning device comprising: i) a plurality of semiconductor lasers (11, 12, 13, 14) for emitting a respective plurality of primary laser beams (41,42,43,44); ii) combining means (6) for combining said primary laser beams into a single combined laser beam (45); iii) scanning means (5) for scanning a surface (7) with said combined laser beam; (iv) detecting means (52) for detecting the power of said combined laser beam; and v) control means (51) responsive to a detected signal from said detecting means for controllably energizing at least one of said semiconductor lasers to control the power of the primary laser beam emitted therefrom and thereby maintain substantially constant the power of said combined laser beam.
Claim 2
Dependent Claim
118 words
A semiconductor laser beam scanning device comprising: i) a plurality of semiconductor lasers (11, 12, 13, 14) for emitting a respective plurality of primary laser beams (41,42,43,44); ii) combining means (6) for combining said primary laser beams into a single combined laser beam (45); iii) scanning means (5) for scanning a surface (7) with said combined laser beam; (iv) detecting means (52) for detecting the power of said combined laser beam; and v) control means (51) responsive to a detected signal from said detecting means for controllably energizing at least one of said semiconductor lasers to control the power of the primary laser beam emitted therefrom and thereby maintain substantially constant the power of said combined laser beam.
Claim 3
Dependent Claim
42 words
A device as claimed in claim 1, wherein said detecting means comprises a laser beam energy detector (52) disposed adjacent to said surface (7) for detecting the power of said combined laser beam (45) in each cycle of scanning of said surface.
Claim 4
Dependent Claim
55 words
A device as claimed in claim 1, wherein said detecting means comprises a beam splitter (92) disposed in a beam path for said combined laser beam (87) for dividing a laser beam (87a) from said combined laser beam, and a laser beam energy detector (52) for detecting the power of said divided laser beam (87a).
Claim 5
Independent Claim
70 words
A device as claimed in either of claims 1 and 2 wherein said semiconductor lasers (11,12,13,14) are arranged to generate the primary laser beams (41,42,43,44) parallel to each other, said scanning means comprises a galvanometer mirror (5) for deflecting said primary laser beams, and said combining means comprises a focusing lens (6) for converging said primary laser beams onto said surface (7) to form said combined laser beam (45) thereat.
Claim 6
Independent Claim
49 words
A device as claimed in either of claims 1 and 3 wherein said combining means comprises a hologram element (90), and said semiconductor lasers (61, 62, 63, 64, 65, 66) are arranged to generate the primary laser beams (81, 82, 83, 84, 85, 86) convergent toward said hologram element.
Claim 7
Independent Claim
71 words
A device as claimed in any one of claims 1 to 5 wherein said control means comprises a laser drive/control circuit (51) including means for comparing said detected signal (P) with a reference laser beam signal representative of a prescribed power of said combined laser beam (45) and for energizing said at least one semiconductor laser (14) based on the difference between said detected signal and said reference laser beam signal.
Claim 8
Independent Claim
113 words
A device as claimed in any one of claims 1 to 5 wherein said control means comprises a laser drive circuit (C4) for generating a drive current to energize said at least one semiconductor laser (14), a comparator (46) for comparing said detected signal (P) with a reference laser beam signal (Sr) representative of a prescribed power of said combined .aser beam (45) and for producing a difference signal (H/L) indicative of the difference between said detected signal and said reference laser beam signal, and a control circuit (D4) responsive to said difference signal for controlling said laser drive circuit to vary said drive current so that said difference signal will be eliminated.
Claim 9
Dependent Claim
48 words
A device as claimed in claim 7, wherein said laser drive circuit comprises a constant-current laser drive circuit with a current setting variable by said control circuit, including a common constant-current laser drive circuit for energizing the semiconductor lasers (11,12,13) except said at least one semiconductor laser (14).
Claim 10
Dependent Claim
57 words
A device as claimed in claim 7, wherein said laser drive circuit comprises a constant-current laser drive circuit (C4) with a current setting variable by said control circuit (D4), including a plurality of constant-current laser drive circuits (Cl, C2, C3) for energizing the respective semiconductor lasers (11, 12, 13) except said at least one semiconductor laser (14).
Claim 11
Dependent Claim
58 words
A device as claimed in claim 7, wherein said laser drive circuit comprises a constant-output laser drive circuit (E4) with a laser drive current variable by said control circuit (D4), including a plurality of constant-output laser drive circuits (El, E2, E3) for energizing the respective semiconductor lasers (11, 12, 13) except said at least one semiconductor laser (14).
Claim 12
Dependent Claim
52 words
A device as claimed in claim 7, wherein said laser drive circuit comprises a constant-output laser drive circuit (55) with a laser drive current variable by said control circuit (56), including a common constant-current laser drive circuit (54) for energizing the semiconductor lasers (11,12,13,14) except said at least one semiconductor laser (14).
References Cited (Backward Citations)
No citation records indexed.
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