Patent US4880966A successfully refreshed from Google Patents.
US4880966A
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US
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Tachometer sensor using a lens system to a in sensing the rotational speed of an object
Assignee: GLOBAL ASSOCIATES Ltd
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Filing: 1988-04-08
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Granted: 1989-11-14
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Expires: 2008-04-08
Abstract
Abstract An optical tachometer sensor for providing output relating to rotational speed of an object. The sensor illuminates a reflective mark on the object with modulated light and focuses that light via a receiving lens arrangement onto a photoelectric sensor which provides signals to conditioning circuitry for controlling output. Lenses in the sensor also form a Galilean telescope or a terrestrial telescope to allow a user to boresight the sensor by viewing the reflective marker through the sensor. A beam splitter or "hot mirror" reverses the optical path of modulated rays generated by the device for forcusing on the photoelectric sensor, while allowing visible light to pass and be aligned by a divergent ocular lens. In the terrestrial telescope embodiment, a convergent inverting lens and ocular lens provide the image for the user and the photoelectric sensor may be located at the focal point of the objective lens or the inverting lens.
Inventors
- 👤 Jeffrey A. Goodrich
- 👤 Charles M. Poe, Jr.
- 👤 Jeffrey A. Prsha
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:05
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/42; G01P3/44; G01P3/48; G01P3/481; G01P3/486
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
239 words
A tachometer sensor for sensing rotational speed of an object, comprising: (a) a light emitting device for illuminating the object; (b) at least one reflective mark on the object for reflecting light rays emitted by the light emitting device; (c) an objective lens located in the path of the light rays emitted by the light emitting device and reflected by the mark; (d) a beam splitter located in the path of light rays reflected by the objective lens and oriented substantially perpendicular to that ray-path, for reflecting a first portion of the rays in a direction substantially opposite and parallel to that in which the first portion of rays strikes the beam splitter and for allowing a second portion of the rays to pass through; (e) a photoelectric sensor located at substantially the focal point of the first portion of the light rays reflected by the objective lens and reflected by the beam splitting means; (f) an ocular lens located in the path of the second portion of light rays reflected by the objective lens and penetrating the beam splitting means, for aligning the second portion of rays so that one using the sensor can view the mark on the rotating object through the sensor in order to align the sensor; (g) driver means for supplying power to the light emitting device; and (h) circuit means for conditioning and providing for output the signals produced by the photoelectric sensor.
Claim 2
Dependent Claim
239 words
A tachometer sensor for sensing rotational speed of an object, comprising: (a) a light emitting device for illuminating the object; (b) at least one reflective mark on the object for reflecting light rays emitted by the light emitting device; (c) an objective lens located in the path of the light rays emitted by the light emitting device and reflected by the mark; (d) a beam splitter located in the path of light rays reflected by the objective lens and oriented substantially perpendicular to that ray-path, for reflecting a first portion of the rays in a direction substantially opposite and parallel to that in which the first portion of rays strikes the beam splitter and for allowing a second portion of the rays to pass through; (e) a photoelectric sensor located at substantially the focal point of the first portion of the light rays reflected by the objective lens and reflected by the beam splitting means; (f) an ocular lens located in the path of the second portion of light rays reflected by the objective lens and penetrating the beam splitting means, for aligning the second portion of rays so that one using the sensor can view the mark on the rotating object through the sensor in order to align the sensor; (g) driver means for supplying power to the light emitting device; and (h) circuit means for conditioning and providing for output the signals produced by the photoelectric sensor.
Claim 3
Dependent Claim
16 words
A device according to claim 1 in which the beam splitting device is a hot mirror.
Claim 4
Dependent Claim
25 words
A device according to claim 1 in which the light emitting device is an infrared emitting diode which emits the first portion of light rays.
Claim 5
Dependent Claim
14 words
A device according to claim 1 in which the photoelectric sensor is a phototransistor.
Claim 6
Dependent Claim
26 words
A device according to claim 1 in which the circuit means contains a peak detector for providing feedback signals to control output of the driver means.
Claim 7
Dependent Claim
28 words
A device according to claim 1 in which the light emitting device, objective lens, beam splitting means, photoelectric sensor and ocular lens are located coaxially to one another.
Claim 8
Dependent Claim
17 words
A device according to claim 1 which the driver means modulates power to the light emitting device.
Claim 9
Dependent Claim
43 words
A device according to claim 2 in which the objective lens is a convergent lens whose focal length substantially equals the distance from the objective lens to the beam splitting device plus the distance from the beam splitting device to the photoelectric sensor.
Claim 10
Dependent Claim
15 words
A device according to claim 3 in which the ocular lens is a divergent lens.
Claim 11
Dependent Claim
38 words
A device according to claim 8 in which the circuit means contains filters for reducing sensitivity of the tachometer sensor to reflections from the mark modulated at frequencies below that of the signal provided by the driver means.
Claim 12
Dependent Claim
48 words
A device according to claim 8 in which an oscillator circuit modulates the driver means and feeds a synchronous demodulator in the circuit means, which synchronous demodulator rejects signals from the photoelectric sensor corresponding to light received by the photoelectric sensor not emitted by the light emitting device.
Claim 13
Dependent Claim
210 words
A tachometer sensor for sensing rotational speed of an object, comprising: (a) a light emitting device for illuminating the object; (b) at least one reflective mark on the object for reflecting light rays emitted by the light emitting device; (c) an objective lens located in the path of the light rays emitted by the light emitting device and reflected by the mark, which objective lens has a focal length f; (d) an inverting lens having a first focal length f a and a second focal length f b , located at a distance substantially f a +f from the objective lens for inverting and refocusing light rays focused by the objective lens; (e) a photoelectric sensor located substantially at the focal point f b from the inverting lens; (f) an ocular lens having a focal length f o located at a distance substantially f b +f o from the inverting lens for aligning rays focused by the inverting lens so that one using the sensor can view the mark on the rotating object through the sensor in order to align the sensor; (g) driver means for supplying power to the light emitting device; and (h) circuit means for conditioning and providing for output the signal produced by the photoelectric sensor.
Claim 14
Dependent Claim
210 words
A tachometer sensor for sensing rotational speed of an object, comprising: (a) a light emitting device for illuminating the object; (b) at least one reflective mark on the object for reflecting light rays emitted by the light emitting device; (c) an objective lens located in the path of the light rays emitted by the light emitting device and reflected by the mark, which objective lens has a focal length f; (d) an inverting lens having a first focal length f a and a second focal length f b , located at a distance substantially f a +f from the objective lens for inverting and refocusing light rays focused by the objective lens; (e) a photoelectric sensor located substantially at the focal point f b from the inverting lens; (f) an ocular lens having a focal length f o located at a distance substantially f b +f o from the inverting lens for aligning rays focused by the inverting lens so that one using the sensor can view the mark on the rotating object through the sensor in order to align the sensor; (g) driver means for supplying power to the light emitting device; and (h) circuit means for conditioning and providing for output the signal produced by the photoelectric sensor.
Claim 15
Dependent Claim
27 words
A device according to claim 12 in which the light emitting device, objective lens, inverting lens, photoelectric sensor and ocular lens are located coaxially to one another.
Claim 16
Dependent Claim
24 words
A device according to claim 12 in which the objective lens, inverting lens and ocular lens are convergent lenses and form a terrestrial telescope.
Claim 17
Dependent Claim
17 words
A device according to claim 12 in which the light emitting device is an infrared emitting diode.
Claim 18
Dependent Claim
14 words
A device according to claim 12 in which the photoelectric sensor is a phototransistor.
Claim 19
Dependent Claim
27 words
A device according to claim 12 in which the circuit means contains a peak detector for providing feedback signals to control output of the power supply means.
Claim 20
Dependent Claim
18 words
A device according to claim 12 in which the driver means modulates power to the light emitting device.
Claim 21
Dependent Claim
38 words
A device according to claim 18 in which the circuit means contains filters for reducing sensitivity of the tachometer sensor to reflections from the mark modulated at frequencies below that of the signal provided by the driver means.
Claim 22
Dependent Claim
48 words
A device according to claim 18 in which an oscillator circuit modulates the driver means and feeds a synchronous demodulator in the circuit means, which synchronous demodulator rejects signals from the photoelectric sensor corresponding to light received by the photoelectric sensor not emitted by the light emitting device.
References Cited (Backward Citations)
US3007051A
Cited
US3508066A
Cited
US3622801A
Cited
US3688570A
Cited
US3654553A
Cited
US3681690A
Cited
US3733892A
Cited
US3802273A
Cited
US3938762A
Cited
US3945256A
Cited
US4158504A
Cited
US4053123A
Cited
US4112774A
Cited
US4184737A
Cited
US4387785A
Cited
US4397520A
Cited
US4531408A
Cited
US4576432A
Cited
US4634255A
Cited
US4655562A
Cited
US4774463A
Cited
US4665622A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-13 | 1993-05-15 | 1993-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-13 | 1997-05-15 | 1997-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-13 | 2001-05-15 | 2001-11-14 | $7700.00 | Window Closed / Lapsed |