Single lens rangefinder device having light emitter and detector

• US 4,460,259 A
• Filed: 12/13/1982
• Issued: 07/17/1984
• Est. Priority Date: 12/13/1982
• Status: Expired due to Fees

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Meyer, James W., Lambeth, David N., Greivenkamp, John E. Jr.
• Primary Examiner(s): Gellner, Michael L.
• Application Number:
  US06/449,330
• Time in Patent Office: 582 Days
• Field of Search: 354/403
• US Class Current: 396/75
• CPC Class Codes: G01S 17/32 using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
• CPC Class Codes: G01S 17/46 Indirect determination of position data

Abstract

A simple rangefinder device, suitable for two-zone ranging applications, comprises a single lens, a light emitter located with respect to the lens to produce a beam of light, and a light detector located with respect to the lens to define a field of view. The effective lens aperture for the emitter and the detector substantially coincide and the field of view of the detector overlaps the light beam in a detection region extending away from the lens for a predetermined distance. Signal processing electronics receive a signal produced by the light detector to produce a signal representing the presence or absence of a reflecting object in the detection region.

Claims

1. A rangefinder device, comprising:

(a) a single lens;

(b) an LED located with respect to said single lens for forming a beam of light said lens defining an effective aperture for said LED;

(c) a photodiode located with respect to said single lens to define a field of view overlapping with said beam of light in a detection region extending a predetermined distance from said lens, for detecting light reflected from an object located in said detection region to produce an electrical signal representative of said detected light, said lens defining an effective aperture for said photodiode, substantially coinciding with said effective aperture for said LED, and said LED and said photodiode being integrated on a common substrate; and

(d) signal processing means responsive to said electrical signal for producing a signal representing the presence or absence of a reflecting object in said detection region.

2. The invention claimed in claim 1, in combination with a photographic camera having a taking lens, a closeup lens element mounted for movement relative to the optical path of said taking lens, and an actuator responsive to a control signal for moving said closeup lens element in response to the signal from said signal processing means.

3. An improved rangefinder device of the type having a light emitter, including a lens, for forming a beam of light to illuminate a spot on an object and a light sensor, including a lens, for sensing light reflected from the object to determine the distance to the object, wherein the improvement comprises, said light emitter lens and said light sensor lens being one and the same and the effective aperture defined by said lens for said emitter and detector being substantially coincident and wherein said light emitter and light sensor comprise solid state devices integrated on a common substrate.

4. A rangefinder device, comprising:

(a) a single lens;

(b) an LED located near one focal point of the lens for illuminating a first generally cylindrical volume of space;

(c) a solid state light sensitive element located adjacent said LED for viewing a second generally cylindrical volume of space through said single lens and producing an output signal in response to light therefrom, the effective aperture defined by said lens for said LED and said light sensitive element being substantially coincident, said first and second volumes overlapping to define a third volume of space extending a predetermined distance from said lens, said LED and light sensitive element being integrated on a common substrate; and

(d) control circuit means responsive to said output signal for detecting if a reflective object is located in said third volume of space.