Control system for camera with multiple opto-sensors

• US 5,481,331 A
• Filed: 04/21/1994
• Issued: 01/02/1996
• Est. Priority Date: 04/21/1994
• Status: Expired due to Fees

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Dunsmore, Clay A., Cocca, J. David
• Primary Examiner(s): Gellner, Michael L.
• Assistant Examiner(s): MILLER, MATTHEW D
• Application Number:
  US08/230,589
• Time in Patent Office: 621 Days
• Field of Search: 354/432, 354/173.1, 354/173.11, 354/195.1
• US Class Current: 396/133
• CPC Class Codes: G03B 1/60 Measuring or indicating length of the used or unused film; Counting number of exposures
• CPC Class Codes: G03B 17/00 Details of cameras or camera bodies; Accessories therefor lens hoods or caps G03B11/04
• CPC Class Codes: G03B 17/425 motor drive cameras

Abstract

In a photographic camera having a plurality of opto-sensors and a microprocessor-based controller, the opto-sensor output signals are coupled via a common bus connection to an input terminal of the controller. A programmably variable output impedance common to the opto-sensors is selectably set for each corresponding selected opto-sensor such that the output signal for each of the selected opto-sensors is at or above a predetermined threshold value at the input to the controller irrespective of differing current output performance of the individual opto-sensors.

Claims

1. A control system for a camera for controlling input of signals from a plurality of opto-sensors to a camera controller comprising:

an opto-sensor bus connector coupling each of the opto-sensors to a common input terminal of said controller;

an effective output load impedance coupled in common to said plurality of opto-sensors and to said bus connector; and

activating means for selectively activating said opto-sensors to provide selected ones of said opto-sensor signals appearing across said output load effective impedance to said controller input terminal by way of said bus connector.

2. A control system according to claim 1 in which said activating means is operative to mutually exclusively activate said opto-sensors to provide individual ones of said signals to said controller input terminal.

3. A control system according to claim 1 in which said effective output load impedance comprises a variable effective impedance and the system further includes means for activating said effective impedance to a predetermined value dependent on the selected ones of said opto-sensors activated by said activating means.

4. A control system according to claim 3 in which said effective output load impedance comprises a programmably settable digital potentiometer.

5. A control system according to claim 3 in which said effective output load impedance comprises a plurality of selectable constant current drivers.

6. A control system for a photographic camera having a camera controller and a plurality of opto-sensors including a data disc opto-sensor positioned in the camera to sense bars and spaces on said data disc;

the control system comprising;

an opto-sensor bus connector coupling each of the opto-sensors to a common input terminal of said controller;

a programmably selectable output effective load impedance coupled in common to said plurality of opto-sensors and to said bus connector; and

activating means for selectively activating said opto-sensors to provide selected ones of said opto-sensor signals appearing across said output load effective impedance to said controller input terminal by way of said bus connector;

said plurality of opto-sensors having respectively different output currents in response to sensing each opto-sensor'"'"'s respective target objects; and

said controller being programmed to calibrate said effective output load impedance by selecting respectively different effective impedance values for at least two of said selected opto-sensors which produce respective sensor output signals of at least a predetermined threshold value at the input terminal of the camera controller.