Self-focusing camera apparatus and method

• US 4,152,061 A
• Filed: 05/01/1978
• Issued: 05/01/1979
• Est. Priority Date: 05/01/1978
• Status: Expired due to Term

• Current Assignee: Gary B. Gordon
• Original Assignee: Gary B. Gordon
• Inventors: Gordon, Gary B.
• Primary Examiner(s): Gellner, Michael L.
• Application Number:
  US05/901,564
• Time in Patent Office: 365 Days
• Field of Search: 354/195, 354/25, 354/81, 358/227, 352/140, 355/56
• US Class Current: 396/50
• CPC Class Codes: G02B 7/305 using a scanner
• CPC Class Codes: H04N 23/67 Focus control based on electronic image sensor signals

Abstract

A method and apparatus are provided which automatically focus a television camera or motion picture camera, or the like, in applications where, for any given camera-pointing direction, the desired subject will lie at a single-valued and predetermined distance from the camera such as on a planar surface. In one embodiment, a mechanical linkage enables a camera, shooting downward onto a flat playing field, to self-focus on any point in that field. In an electronic embodiment, a learn mode is included that handles events on more complicated terrains such as mountainous terrain in skiing events. In these cases, the self-focusing action is instantaneous, continuous and accurate.

Claims

1. Camera focusing apparatus for a camera having an adjustable-focus lens operated from a fixed position relative to a horizontal object plane, the apparatus comprising:

support means for the camera rotatable at least about a substantially horizontal axis;

angle-sensing means disposed with respect to said support means to produce an output substantially proportional to the sine of the angular position of the camera about said horizontal axis;

scaling means coupled to the angle-sensing means for altering said output of the angle-sensing means by a constant of proportionality which is indicative of and inversely proportional to the height of the camera above the object plane; and

actuating means for converting the altered ouput of said scaling means to focus-adjusting motion of the lens of the camera.

2. Camera focusing system as in claim 1 wherein:

said angle-sensing means responds to the declination angle of the camera about said axis relative to horizontal; and

said scaling means includes a movable coupling disposed to be set at a selectable distance from the horziontal axis.

3. Camera-focusing apparatus for a camera having a focus-adjustable lens operated at a fixed location relative to the object, the apparatus comprising:

support means for the camera disposed to allow rotation thereof about substantially horizontal and vertical axes;

angle-sensing means disposed to produce outputs representative of the pointing directions of th camera relative to said support means;

lens position-sensing means for producing an output indicative of the lens focus setting of the camera;

4. storage means coupled to said angle-sensing means and said lens position-sensing means for selectively storing the output indicative of the sensed lens position and corresponding outputs representative of the sensed camera-pointing directions;

means for selectively recalling from said storage means the stored output indicative of lens focus setting corresponding substantially to the outputs produced by the angle-sensing means in response to the camera attaining a selected pointing direction; and

lens-positioning mens responsive to said recalled output for altering the lends focus adjustment in response thereto.

5. The method of adjusting the focus of a camera operated from a fixed position relative to a horizontal object plane, the method comprising:

supporting the camera for rotation at least about a substantially horizontal axis;

producing an output substantially proportional to the sine of the angular position of the camera about the axis;

scaling the sine output relative to the height of the camera relative to the object plane; and

applying the scaled output to the camera as focus-adjusting motion of the lens thereof.

6. The method of adjusting the focus of a camera operated at a fixed position relative to an object, the method comprising:

supporting the camera for rotation about substantially horizontal and vertical axes;

producing outputs representative of the angular positions of the camera about the axes;

producing an output representative of the focus setting of the camera pointing at an object located in the directions identified by the angular positions aout the axes;

storing the output representative of the focus setting at the corresponding angular positions of the camera about the axes;

selectively recalling the stored outputs representative of focus settings of the camera in response to the camera being oriented at the angular positions corresponding thereto; and

altering the focus setting of the camera in response to the recalled focus-setting outputs.