US3887273A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speedometer optical projection system
Assignee: Individual
•
Filing: 1973-07-27
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Granted: 1975-06-03
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Expires: 1993-07-27
Abstract
Abstract A system for projecting a speedometer or other instrument reading as a virtual image, focused at infinity, into the field of view of a vehicle operator includes the windshield and a lens system containing a lens that substantially corrects aberrations caused by curvature of the windshield.
Inventors
- 👤 David Griffiths
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:03
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/01; G02B27/0101; B; B60; B60K; B60K35/00; B60K35/20; B60K37/00; B60K37/20; G01; G01P; G01P1/00; G01P1/07; G01P1/08; G03; G03B; G03B21/00; G03B21/14; G03B21/20; B60K2360/00; B60K2360/20; B60K2360/33; B60K2360/334; G02B27/0149; G02B2027/0169
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
147 words
In a vehicle with an instrument panel including a speedometer or the like having a movable scale with indicia providing vehicle condition information for the vehicle operator, a system for projecting said information as a luminous image at infinite focus substantially in the operator''s forward field of view comprising a transparent windshield concave to the interior of the vehicle and of substantially spherical curvature, a projection lens for projecting parallel light rays on the inside surface of said transparent windshield, a light source for illuminating said scale and located on the opposite side of the scale from the lens, and an optical correcting element in the system for sharply focusing said image to overcome aberration produced by the curvature of the windshield, said scale being positioned at less than the focal length of the projection lens to correct for focus shift produced by curvature of the windshield.
Claim 2
Dependent Claim
147 words
In a vehicle with an instrument panel including a speedometer or the like having a movable scale with indicia providing vehicle condition information for the vehicle operator, a system for projecting said information as a luminous image at infinite focus substantially in the operator''s forward field of view comprising a transparent windshield concave to the interior of the vehicle and of substantially spherical curvature, a projection lens for projecting parallel light rays on the inside surface of said transparent windshield, a light source for illuminating said scale and located on the opposite side of the scale from the lens, and an optical correcting element in the system for sharply focusing said image to overcome aberration produced by the curvature of the windshield, said scale being positioned at less than the focal length of the projection lens to correct for focus shift produced by curvature of the windshield.
Claim 3
Dependent Claim
147 words
In a vehicle with an instrument panel including a speedometer or the like having a movable scale with indicia providing vehicle condition information for the vehicle operator, a system for projecting said information as a luminous image at infinite focus substantially in the operator''s forward field of view comprising a transparent windshield concave to the interior of the vehicle and of substantially spherical curvature, a projection lens for projecting parallel light rays on the inside surface of said transparent windshield, a light source for illuminating said scale and located on the opposite side of the scale from the lens, and an optical correcting element in the system for sharply focusing said image to overcome aberration produced by the curvature of the windshield, said scale being positioned at less than the focal length of the projection lens to correct for focus shift produced by curvature of the windshield.
Claim 4
Dependent Claim
147 words
In a vehicle with an instrument panel including a speedometer or the like having a movable scale with indicia providing vehicle condition information for the vehicle operator, a system for projecting said information as a luminous image at infinite focus substantially in the operator''s forward field of view comprising a transparent windshield concave to the interior of the vehicle and of substantially spherical curvature, a projection lens for projecting parallel light rays on the inside surface of said transparent windshield, a light source for illuminating said scale and located on the opposite side of the scale from the lens, and an optical correcting element in the system for sharply focusing said image to overcome aberration produced by the curvature of the windshield, said scale being positioned at less than the focal length of the projection lens to correct for focus shift produced by curvature of the windshield.
Claim 5
Dependent Claim
16 words
The invention as set forth in claim 1 wherein said correcting element is a cylindrical lens.
Claim 6
Dependent Claim
27 words
The invention as set forth in claim 2 wherein said cylindrical lens is negative and positioned so that its curvature is along the length of the vehicle.
Claim 7
Dependent Claim
27 words
The invention as set forth in claim 2 wherein said cylindrical lens is positive and positioned so that its curvature is across the width of the vehicle.
Claim 8
Dependent Claim
142 words
In a vehicle with an instrument panel including a speedometer or the like having a movable scale with indicia providing vehicle condition information for the vehicle operator, a system for projecting said information as a luminous image at infinite focus substantially in the operator''s forward field of view comprising a transparent windshield concave to the interior of the vehicle and of substantially spherical curvature, a projection lens for projecting parallel light rays on the inside surface of said transparent windshield, a light source for illuminating said scale and located on the opposite side of the scale from the lens, and an optical correcting element in the system for sharply focusing said image to overcome aberration produced by the curvature of the windshield, said correcting element being a negative cylindrical lens positioned so that its curvature is along the length of the vehicle.
Claim 9
Dependent Claim
142 words
In a vehicle with an instrument panel including a speedometer or the like having a movable scale with indicia providing vehicle condition information for the vehicle operator, a system for projecting said information as a luminous image at infinite focus substantially in the operator''s forward field of view comprising a transparent windshield concave to the interior of the vehicle and of substantially spherical curvature, a projection lens for projecting parallel light rays on the inside surface of said transparent windshield, a light source for illuminating said scale and located on the opposite side of the scale from the lens, and an optical correcting element in the system for sharply focusing said image to overcome aberration produced by the curvature of the windshield, said correcting element being a negative cylindrical lens positioned so that its curvature is along the length of the vehicle.
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) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |