Automatic tracking/image sensing device

• US 5,963,248 A
• Filed: 10/06/1997
• Issued: 10/05/1999
• Est. Priority Date: 03/22/1995
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kawamura, Hiroshi, Koyanagi, Masakazu, Hosonuma, Naoyasu, Tomitaka, Tadafusa, Ohkawa, Jun
• Primary Examiner(s): Tung, Bryan
• Assistant Examiner(s): Philippe, Gims S.
• Application Number:
  US08/944,487
• Time in Patent Office: 729 Days
• Field of Search: 348/96, 348/169, 348/170, 348/171, 348/172, 348/117, 348/207, 348/224, 348/369, 382/103, 364/571, 324/207.12, 360/77.06, 359/700
• US Class Current: 348/169
• CPC Class Codes: G01S 3/7864 T.V. type tracking systems
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6811 based on the image signal
• CPC Class Codes: H04N 23/687 by shifting the lens or sensor position

Abstract

The automatic tracking/image sensing device includes a lens barrel for supporting an image sensing lens, a support mechanism for supporting the lens barrel in such a way that the lens barrel can be moved, driver for driving the lens barrel, an image sensor installed at a location in close proximity to an image created by the image sensing lens, a video signal processor for generating a video signal based on a signal output by the image sensor, an object position detector for computing a positional deviation from the current position of the object to the center of the screen in accordance with the video signal generated by the video signal processor, a deflection detecting sensor for detecting the deflection of the lens barrel and a lens barrel posture controller for adjusting the angle of the lens barrel by using a driver in accordance with the positional deviation and the deflection. There can thus be provided an automatic tracking image sensing device with a simple configuration for automatic tracking by deflection correction.

Claims

1. An automatic tracking/image sensing device comprising:

a lens barrel for supporting an image sensing lens;

a support mechanism for supporting said lens barrel in such a way that said lens barrel can be moved about a vertical axis and a horizontal axis;

driving means for driving said lens barrel in yawing and pitching directions about said vertical and horizontal axes, respectively, to change a posture of said lens barrel;

image sensing means installed at a location in close proximity to an image created by said image sensing lens for sensing the image and producing picture element data therefrom;

video signal processing means for generating a video signal constituting a screen and based on the picture element data output by said image sensing means;

object position detecting means for detecting the current position of an object and computing a positional deviation from the current position of said object to the center of said screen in accordance with said video signal generated by said video signal processing means;

a plurality of angular position sensors for detecting an angular position of said lens barrel in said yawing and pitching directions about said respective vertical and horizontal axes;

lens barrel posture controlling means for adjusting an angle of said lens barrel about at least one of said vertical and horizontal axes of said lens barrel; and

a deflection detecting sensor attached to a stationary portion of said automatic tracking/image sensing device for detecting a deflection of said lens barrel resulting from the angle adjustment by said posture controlling means,

wherein said angle about said at least one of said vertical and horizontal axes of said lens barrel is adjusted by activating said driving means in accordance with said positional deviation output by said object position detecting means, said deflection of said lens barrel detected by said deflection detecting sensor, and said angular positions detected by said angular position sensors, without correcting in a direction opposite to a direction of panning or tilting specified by a user.

2. An automatic tracking/image sensing device according to claim 1 wherein said purality of predetermined axes comprise pitching and yawing axes.

3. An automatic tracking/image sensing device according to claim 2 wherein said driving means directly drives said lens barrel.

4. An automatic tracking/image sensing device according to claim 2 wherein said lens barrel posture controlling means differentiates changes in signal output by said plurality of position sensors in order to find a current speed of said lens barrel.

5. An automatic tracking/image sensing device accroding to claim 4 wherein said lens barrel posture controlling means subtracts a signal output by said plurality of position sensors from a positional deviation output by said object position detecting means in order to find a speed of said object relative to said current speed.

6. An automatic tracking/image sensing device according to claim 5 wherein said lens barrel posture controlling means detects a desired deflection speed of said lens barrel from a deflection value output by said deflection detecting sensor and adds said desired deflection speed to said relative speed to obtain a target speed.

7. An automatic tracking/image sensing device according to claim 6 wherein said position sensors each comprise a rotation detecting multi-pole magnet having a circular from and surrounding a rotation shaft of said lens barrel and having firmly attached thereto a magnet-resistive device facing said rotation detecting multi-pole magnet, wherein said magneto-resistive device generating a plurality of signals with respective phases different from each other.

8. An automatic tracking/image sensing device according to claim 7 wherein said lens barrel posture controlling means differntiates changes in a signal output by said position sensors in order to find said current speed of said lens barrel and subtracts said current speed from said target speed to obtain a target speed change.

9. An automatic tracking/image sensing device according to claim 8 wherein said lens barrel posture controlling means generates a driving signal to control said driving means to alter said lens barrel speed on said target speed change.