US3625612A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical derotator employing mirror pairs to view a rotating body
Assignee: Comstock and Wescott Inc
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Filing: 1969-07-11
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Granted: 1971-12-07
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Expires: 1989-07-11
Abstract
Abstract For viewing an object rotating about an axis at a predetermined angular velocity to make the object appear stationary, apparatus comprising mirrors for reflecting rays from the object to a viewing location, the mirrors comprising one or more pairs of reflectors, the reflecting surfaces of each pair including an angle less than 180* for reflecting incident light from one reflector to the other and thence to said location, the angle being equal to 180* divided by an even number, one of the pairs comprising a derotator rotatable in the direction opposite to that of the object, the sum of the absolute values of the angular velocities of all the pairs equaling one-half the absolute value of the angular velocity of the object.
Inventors
- 👤 John A Decker Jr
- 👤 Martin O Harwit
- 👤 Domenico S Sarcia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:46
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/64; G02B27/642; G02B17/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
149 words
For viewing an object rotating about an axis at a predetermined angular velocity, apparatus comprising means for reflecting rays from the object to a viewing location, said means comprising a predetermine number of plane reflectors arranged in one or more pairs, the reflecting surfaces of each pair including an angle less than 180* for reflecting incident light directly from one reflector to the other and thence toward said location, said angle being equal to 180* divided by an even number, means for rotating one or more of said pairs on the axis bisecting the angle between each pair in a direction to reduce the apparent rotational velocity of the object, at least one pair being rotated in the same direction as the object, the sum of the absolute values of the angular velocities of all the pairs equaling one-half the absolute value of the angular velocity of the object.
Claim 2
Dependent Claim
149 words
For viewing an object rotating about an axis at a predetermined angular velocity, apparatus comprising means for reflecting rays from the object to a viewing location, said means comprising a predetermine number of plane reflectors arranged in one or more pairs, the reflecting surfaces of each pair including an angle less than 180* for reflecting incident light directly from one reflector to the other and thence toward said location, said angle being equal to 180* divided by an even number, means for rotating one or more of said pairs on the axis bisecting the angle between each pair in a direction to reduce the apparent rotational velocity of the object, at least one pair being rotated in the same direction as the object, the sum of the absolute values of the angular velocities of all the pairs equaling one-half the absolute value of the angular velocity of the object.
Claim 3
Dependent Claim
15 words
Apparatus according to claim 1 wherein said reflecting means is highly reflective in the infrared.
Claim 4
Dependent Claim
10 words
Apparatus according to claim 1 wherein said angle is 90*.
Claim 5
Dependent Claim
30 words
Apparatus according to claim 1 further characterized by a telescope on the means for rotating directed toward the center of the object when the object is centered on said axis.
Claim 6
Dependent Claim
23 words
Apparatus according to claim 1 wherein said one pair of reflectors has an opening on said axis through which the object is viewed.
Claim 7
Dependent Claim
14 words
Apparatus according to claim 1 wherein said number of pairs is greater than one.
Claim 8
Dependent Claim
37 words
Apparatus according to claim 6 wherein two of said pairs are arranged for multiple reflections therebetween and one pair rotates at one-half the angular velocity of said object divided by the number of reflections off each pair.
Claim 9
Dependent Claim
12 words
Apparatus according to claim 7 wherein one of said pairs is stationary.
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) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |