Patent US4940889A successfully refreshed from Google Patents.
US4940889A
Expired / Lapsed
US
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Method and apparatus for visual indication of optical alignment of photoelectric switch
Assignee: Chinon KK
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Filing: 1989-08-15
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Granted: 1990-07-10
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Expires: 2009-08-15
Abstract
Abstract An alignment system for photoelectric switch includes a variable frequency oscillator producing a frequency which varies according to a light reception signal from a light receiving element in the photoelectric switch. A light emitting device is energized by the output of the variable frequency oscillator to give a visual indication of alignment. A threshold compares the amplitude of the light reception signal with a preset voltage. When the light reception signal exceeds the preset voltage, a logic element provide steady illumination of the light emitting device as an indication that alignment is completed. A lower threshold is then applied to the threshold to keep the light emitting device steadily illuminated until misalignment or propagation conditions reduce the amount of light received.
Inventors
- 👤 Shoichi Ono
- 👤 Atsuhito Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:00
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/26; G01B11/27; G01B11/272; G01V; G01V8/00; G01V8/10; G01V8/12; G08; G08B; G08B13/00; G08B13/18; G08B13/181; G08B13/183
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
93 words
An alignment system for aligning an optical axis of a light beam with a light receiving element, comprising: means for producing a light reception signal having an amplitude related to an amount of light received by said light receiving element; a light; means for flashing said light at a frequency related to said amplitude; means for halting said flashing when said amplitude exceeds a reference voltage; and said reference voltage being a value that is exceeded by said amplitude when alignment of said optical axis with said light receiving element is substantially optimum.
Claim 2
Dependent Claim
93 words
An alignment system for aligning an optical axis of a light beam with a light receiving element, comprising: means for producing a light reception signal having an amplitude related to an amount of light received by said light receiving element; a light; means for flashing said light at a frequency related to said amplitude; means for halting said flashing when said amplitude exceeds a reference voltage; and said reference voltage being a value that is exceeded by said amplitude when alignment of said optical axis with said light receiving element is substantially optimum.
Claim 3
Dependent Claim
35 words
An alignment system according to claim 2, further comprising means for changing said reference voltage to a lower value, whereby flashing of said light is prevented until said amplitude is reduced below said lower value.
Claim 4
Independent Claim
84 words
A method for aligning an optical axis of a light beam with a light receiving element, comprising: producing a light reception signal having an amplitude related to an amount of light received by said light receiving element; flashing a light at a frequency related to said amplituede; halting said flashing when said amplitude exceeds a reference voltage; and said reference voltage being a value that is exceeded by said amplitude when alignment of said optical axis with said light receiving element is substantially optimum.
Claim 5
Independent Claim
84 words
A method for aligning an optical axis of a light beam with a light receiving element, comprising: producing a light reception signal having an amplitude related to an amount of light received by said light receiving element; flashing a light at a frequency related to said amplituede; halting said flashing when said amplitude exceeds a reference voltage; and said reference voltage being a value that is exceeded by said amplitude when alignment of said optical axis with said light receiving element is substantially optimum.
Claim 6
Dependent Claim
32 words
A method according to claim 3, further comprising changing said reference voltage to a lower value, whereby flashing of said light is prevented until said amplitude is reduced below said lower value.
Claim 7
Dependent Claim
117 words
An alignment system for aligning an optical axis of a light beam with a light receiving element, comprising; means for producing a light reception signal having an amplitude related to an amount of light recieved by said light receiving element; a light; means for flashing said light at a frequency related to said amplitude; means for halting said flashing when said amplitude exceeds a reference voltage; said reference voltage being a value that is exceeded by said amplitude when alignment of said optical axis with said light receiving element is substantially optimum; and automatic means for replacing said reference voltage with a second reference voltage having a smaller value when said means for halting halts said flashing.
Claim 8
Dependent Claim
117 words
An alignment system for aligning an optical axis of a light beam with a light receiving element, comprising; means for producing a light reception signal having an amplitude related to an amount of light recieved by said light receiving element; a light; means for flashing said light at a frequency related to said amplitude; means for halting said flashing when said amplitude exceeds a reference voltage; said reference voltage being a value that is exceeded by said amplitude when alignment of said optical axis with said light receiving element is substantially optimum; and automatic means for replacing said reference voltage with a second reference voltage having a smaller value when said means for halting halts said flashing.
Claim 9
Dependent Claim
121 words
An alignment system for aligning an optical axis of a light beam with a light receiving element, comprising: means for producing a light reception signal having an amplitude related to an amount of light received on said light receiving element; a variable frequency oscillator responsive to said light reception signal for producing a frequency that is variable with said amplitude; means for comparing said amplitude with a threshold; a logic device responsive to said frequency and said means for comparing for producing a variable frequency output when said light reception signal is less than said amplitude, and for producing steady signal when said light reception signal exceeds said threshold; and an indicating device energized by an output of said logic device.
Claim 10
Dependent Claim
121 words
An alignment system for aligning an optical axis of a light beam with a light receiving element, comprising: means for producing a light reception signal having an amplitude related to an amount of light received on said light receiving element; a variable frequency oscillator responsive to said light reception signal for producing a frequency that is variable with said amplitude; means for comparing said amplitude with a threshold; a logic device responsive to said frequency and said means for comparing for producing a variable frequency output when said light reception signal is less than said amplitude, and for producing steady signal when said light reception signal exceeds said threshold; and an indicating device energized by an output of said logic device.
Claim 11
Dependent Claim
16 words
An alignment system according to claim 6, werein said indicating device is a light emitting device.
Claim 12
Dependent Claim
18 words
An alignment system according to claim 6, further comprising means for replacing said threshold with a lower threshold.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-09 | 1994-01-08 | 1994-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-09 | 1998-01-08 | 1998-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-09 | 2002-01-08 | 2002-07-10 | $7700.00 | Window Closed / Lapsed |