Claims
- 1. A mark device comprising:
- a laser oscillating unit outputting a laser beam;
- deflecting means for cyclicly deflecting said laser beam through a predetermined scan angle to an abject surface;
- receiving means for reading said laser beam upon reflection from said object surface;
- scan detecting means for outputting a scan termination signal after each of said cyclical defections of said laser beam by said deflecting means; and
- controller means for varying output energy of said laser beam in response to said scan termination signal, said controller means varying said output energy by a step in response to each of said scan termination signals, said output energy, emitted between receipt of any two consecutive scan termination signals by said controller means, having a constant magnitude independent of an amount of laser beam energy reflected from said object surface.
- 2. A mark reading device as in claim 1, wherein
- at least one of said steps corresponds to an energy level lower than a typically set laser output energy level;
- at least one of said steps corresponds to an energy level equal to said typically set laser output energy level; and
- at least one of said steps corresponds to an energy level higher than said typically set laser output energy level.
Priority Claims (1)
Number |
Date |
Country |
Kind |
1-4015 |
Jan 1989 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 07/460,523, filed on Jan. 3, 1990, which was abandoned upon the filing hereof.
US Referenced Citations (6)
Continuations (1)
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Number |
Date |
Country |
Parent |
460523 |
Jan 1990 |
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