Imaging device with hand wobble display circuit

• US 4,862,277 A
• Filed: 09/29/1988
• Issued: 08/29/1989
• Est. Priority Date: 10/19/1987
• Status: Expired due to Fees

• Current Assignee: NEC Home Electronics, Ltd. (NEC Corporation)
• Original Assignee: NEC Home Electronics, Ltd. (NEC Corporation)
• Inventors: Iwaibana, Kunio
• Primary Examiner(s): Ng, Jin F.
• Assistant Examiner(s): BRINICH, STEPHEN M
• Application Number:
  US07/250,723
• Time in Patent Office: 334 Days
• Field of Search: 358/222, 358/105, 358/109, 358/125, 358/126, 358/139, 358/224
• US Class Current: 348/208.15
• CPC Class Codes: H04N 23/634 Warning indications
• 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

Abstract

An imaging device such as a video camera having a viewfinder for displaying an imaging signal to the photographer which indicates the degree of hand wobble (i.e., movement of the camera by the photographer). A hand wobble display circuit generates this imaging signal for the viewfinder by generating a field-difference or a frame-difference signal of the electronic viewfinder signal and displaying the difference signal on the viewfinder. The magnitude of the difference signal can be used to determine the degree of hand wobble.

Claims

1. An imaging device for reproducing images comprising:

a viewfinder for displaying an imaging signal representing the image to be reproduced to a user of said imaging device; and

a hand wobble display circuit, connected to said viewfinder, for generating a difference signal from said imaging signal and displaying said difference signal on said viewfinder, the magnitude of said difference signal indicating the degree of hand wobble of said imaging device by said user.

2. An imaging device in accordance with claim 1, wherein said difference signal is a frame-difference signal representing the difference in said imaging signal between successive frames.

3. An imaging device in accordance with claim 2, wherein said hand wobble display circuit comprises an image memory for storing a frame of said imaging signals, a subtracter for subtracting stored imaging signals of a previous frame from the present frame of imaging signals so as to generate said frame-difference signal, and an adder for adding said frame-difference signal to the present frame of imaging signals for display on said viewfinder.

4. An imaging device in accordance with claim 2, wherein said hand wobble display circuit comprises an image memory for storing a frame of said imaging signals, a subtracter for subtracting stored imaging signals of a previous frame from the present frame of imaging signals so as to generate said frame-difference signal, at least one comparator for comparing said frame-difference signal to at least one threshold, and an alarm driving circuit for lighting at least one alarm light on said viewfinder for each threshold exceeded by said frame-difference signal.

5. An imaging device in accordance with claim 4, wherein said at least one alarm light is disposed along the periphery of the displayed image frame of said viewfinder.

6. An imaging device in accordance with claim 1, wherein said difference signal is a field-difference signal representing the difference in said imaging signal between successive fields.

7. An imaging device in accordance with claim 6, wherein said hand wobble display circuit comprises an image memory for storing a field of said imaging signals, a subtracter for subtracting stored imaging signals of a previous field from the present field of imaging signals so as to generate said field-difference signal, and an adder for adding said field-difference signal to the present field of imaging signals for display on said viewfinder.

8. An imaging device in accordance with claim 6, wherein said hand wobble display circuit comprises an image memory for storing a field of said imaging signals, a subtracter for subtracting stored imaging signals of a previous field from the present field of imaging signals so as to generate said field-difference signal, at least one comparator for comparing said field-difference signal to at least one threshold, and an alarm driving circuit for lighting at least one alarm light on said viewfinder for each threshold exceeded by said field-difference signal.

9. An iaging device in accordance with claim 8, wherein said at least one alarm light is disposed along the periphery of the displayed image field of said viewfinder.