Image pickup system capable of reproducing a stereo and/or a nonstereo image by the use of a single optical system

• US 4,613,899 A
• Filed: 08/10/1984
• Issued: 09/23/1986
• Est. Priority Date: 08/12/1983
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Nagura, Riichi, Kuwano, Ryushi
• Primary Examiner(s): Britton, Howard W.
• Application Number:
  US06/639,950
• Time in Patent Office: 774 Days
• Field of Search: 358/88, 358/91, 358/92, 358/109, 358/901
• US Class Current: 348/50
• CPC Class Codes: G01C 11/025 by scanning the object

Abstract

In an image pickup system (15) which is carried on a craft (16) capable of flying along a flight path over an object zone, a single optical system (40) is disposed in the craft to form, on a focussing area (44), optical images of partial zones lying transversely of the flight path in the object zone. Forward and backward ones of the optical images that are picked up from forward and backward partial zones (P and Q) spaced apart from each other along the flight path are transduced into electrical signals by the use of photoelectric transducing members (41 and 42) placed on the focussing area with a gap left therebetween. The electrical signals are processed so that the forward and the backward images are concurrently reproduced on board the craft or in a terrestrial station to provide a stereo image. The forward optical image may be used to predict an intermediate one of the optical images that is to be picked up through a photoelectric transducing member (43) from an intermediate partial zone (R) between the forward and the backward partial zones. The intermedate optical image is processed to reproduce a high resolution image in accordance with a result of prediction.

Claims

1. An image pick up system for use with a craft capable of flying along a flight path over over an object zone to be imaged, said system comprising:

(A) a single optical system for projecting an image of said object zone onto an image plane, said image plane having;

(1) a forward zone onto which said optical system projects an image of a first portion of said object zone; and

(2) a rearward zone onto which said optical system projects an image of a second portion of said object zone;

said first portion of said object zone being located at a position forward of said second portion of said object zone relative to the movement of said craft along said flight path whereby said forward zone of said image plane receives a forward optical image of a forward portion of said object zone and said rearward zone of said image plane receives a rearward optical image of a rearward portion of said object zone;

(B) first transducer means for converting only said forward optical image into forward electrical signals representative of said forward portion of said object zone;

(C) second transducer means for converting only said rearward optical image into backward electrical signals representative of said rearward portion of said object zone; and

(D) signal processing means for processing said forward and backward electrical signals.

2. An image pickup system as claimed in claim 1, wherein said signal processing means comprises:

delay means for giving a predetermined delay to said forward one of the electrical signals to produce a delayed electrical signal, said predetermined delay being such that said delayed electrical signal appears concurrent with said backward one of the electrical signals; and

image reproducing means responsive to said delayed electrical signal and to said backward one of the electrical signals for producing a stereo image of said object zone.

3. An image pickup system as claimed in claim 1, wherein said signal processing means comprises:

signal disposing means for disposing said forward and said backward electrical signals separately of said craft; and

means to be mounted on said craft for transmitting the forward and the backward electrical signals transduced by said photoelectric transducing members to said signal disposing means as a transmission signal.

4. An image pickup system as claimed in claim 3, wherein said signal disposing means comprises:

6. An image pick up system as claimed in claim 1, wherein said image plane is an imaginary plane.

7. An image pick up system as claimed in claim 1, wherein said first and second transducer means are each located in said image plane.

8. An image pick up system as claimed in claim 1, wherein said first transducer means is separate from said second transducer means.

9. An image pick up system as claimed in claim 1, wherein said signal processing means processes said forward and backward electrical signals to generate a stereo image as a function of both said forward and backward electrical signals.

10. An image pick up system as claimed in claim 1, wherein said optical system projects a single image onto said image plane.

11. An image pickup system as claimed in claim 9, wherein said signal processing means comprises:

a signal processing element having a controllable processing speed and coupled to said second transducer means for processing said rearward electrical signal at said controllable processing speed to produce a processed electrical signal;

storage means accessed by a controllable access speed and coupled to said signal processing element for storing said processed electrical signal; and

control means coupled to said second first transducer means and to said storage means and said signal processing element for controlling said access speed and said processing speed with reference to said forward one of the electrical signals.

12. An image pickup system as claimed in claim 10, said forward electrical signal being a succession of pulses having a predetermined readout frequency and amplitudes variable between a maximum and a minimum level of said forward optical image, both of said maximum and said minimum levels inclusive, wherein said control means comprises:

amplitude classifying means having at least one threshold level between said maximum and said minimum levels, both exclusive, and coupled to said first transducer means for classifying said pulse succession into a plurality of partial pulse successions with reference to said at least one threshold level;

counter means coupled to said amplitude classifying means for individually counting said partial pulse successions a predetermined duration to individually produce counts, respectively;

comparator means for comparing said counts with predetermined reference numbers to produce results of comparison, respectively;

detection means responsive to said results of comparison for detecting said forward optical image to control said access speed and said processing speed.

13. An image pick up system as claimed in claim 1, wherein said first and second transducer means each include a respective linear array of transducer elements.

14. An image pick up system as claimed in claim 12, wherein said linear arrays of transducer elements are positioned parallel to one another.

15. An image pick up system as claimed in claim 13, wherein said linear arrays of transducer elements are positioned perpendicular to said flight path.

5. means for receiving said forward and said backward electrical signals as a received forward signal and a received backward signal which carry said forward and said backward optical images, respectively;

delaying means for giving a prescribed delay to said received forward signal to produce a delayed forward signal, said prescribed delay being such that said delayed forward signal appears concurrent with said received backward signal; and

image reproducing reproducing means resposive to said delayed forward signal and said received backward signal for reproducing a stereo image of said object zone.