Camera system

• US 4,878,751 A
• Filed: 03/24/1989
• Issued: 11/07/1989
• Est. Priority Date: 01/21/1985
• Status: Expired due to Term

• Current Assignee: Minolta Camera Kabushiki Kaisha
• Original Assignee: Minolta Camera Kabushiki Kaisha
• Inventors: Yoshida, Tadahiro, Nakai, Masaaki, Taniguchi, Nobuyuki, Omaki, Takanobu, Nakasa, Masayuki, Kikukawa, Yoshiiku, Kitaura, Mashio
• Primary Examiner(s): PERKEY, WILLIAM B
• Application Number:
  US07/328,311
• Time in Patent Office: 228 Days
• Field of Search: 354/410, 354/412, 354/413, 354/416, 354/417, 354/429, 354/431, 354/432, 354/105, 354/106, 354/109, 354/289.1, 354/288 R, 354/288 A, 354/288 B, 354/288 E , 354/295
• US Class Current: 396/222
• CPC Class Codes: G03B 7/091 Digital circuits

Abstract

A camera system including a camera body and a camera accessory attachable to the camera body, such as an interchangeable back lid, an interchangeable lens, a flash device and so on, is disclosed. In the system, a plurality of circuits provided in plurality of camera accessories are controlled by a microcomputer provided in the camera body. Data is transmitted between the microcomputer and the circuits using a serial data bus and synchronizing clock line connected therebetween. The circuit to receive the data sent from the microcomputer, or the circuit which should send the data to the microcomputer are selected by the microcomputer through chip select lines provided between the microcomputer and each circuit.

Claims

1. A camera system including a camera body and an adaptor attachable to the camera body, comprising;

means, provided in the camera body, for measuring light from an object to be photographed to produce light measuring signal indicating the measured light amount;

means, provided in the camera body, for producing film sensitivity signal corresponding to film sensitivity;

first means, provided in the camera body, for calculating exposure value based on the light measuring signal and the film sensitivity signal;

means, provided in the camera body, for transmitting the light measuring signal and the film sensitivity signal to the adaptor attached to the camera body;

means, provided in the camera body, for discriminating whether the adaptor is attached to the camera body;

second means, provided in the adaptor, for calculating exposure value based on the light measuring signal and the film sensitivity signal;

means, provided in the camera body, for reading the exposure value calculated by second calculating means when said discriminating means discriminates that the adaptor is being attached to the camera body; and

means, provided in the camera body, for controlling exposure operation of the camera in accordance with the exposure value read by the reading means when said discriminating means discriminates that the adaptor is being attached to the camera body, and in accordance with the exposure value calculated by the first calculating means when said discriminating means discriminates that the adaptor is not being attached to the camera body.

2. An adaptor attachable to a camera body for controlling exposure operation of the camera body, comprising;

means for reading light measuring signal which corresponds to light amount from an object to be photographed, said light amount being measured in the camera body;

means for calculating exposure value in accordance with the light measuring signal based on the calculation different from the calculation operating in the camera body;

means for transmitting the calculated exposure value towards the camera body in order that exposure operation of the camera body is controlled in accordance with the exposure value calculated by the calculating means.

3. An adaptor attachable to a camera body for controlling exposure operation of the camera body, comprising;

means for reading light measuring signal which corresponds to light amount from an object to be photographed, said light amount being measured in the camera body;

means for calculating exposure value in accordance with the light measuring signal based on the calculation which is not prepared in the camera body;

means for transmitting the calculated exposure value towards the camera body in order that exposure operation of the camera body is controlled in accordance with the exposure value calculated by the calculating means.

4. An adaptor as claimed in claim 3, wherein said calculating means includes means for calculating exposure value by averaging plurality of light measuring signals.

5. An adaptor as claimed in claim 3, wherein said calculating means includes means for calculating exposure value by calculating a center value between maximum value and minimum value among plurality of light measuring signals.

6. An adaptor as claimed in claim 3, wherein said calculating means includes means for calculating exposure value by subtracting a predetermined value from maximum value among plurality of light measuring signals.

7. An adaptor as claimed in claim 3, wherein said calculating means includes means for calculating exposure value by adding a predetermined value to minimum value among plurality of light measuring signals.

8. An adaptor as claimed in claim 3, wherein said calculating means includes means for producing shifting signal which indicates shifting amount of exposure value between successive two photographies, means for producing frame number signal which indicates frame number of successive photographies, and means for calculating exposure value at each photographies in accordance with the shifting signal and the frame number signal so that exposure value is calculated at each photographies by shifting exposure value according to remaining frame number and shifting amount.

9. A camera accessory attachable to a camera body, comprising;

means for receiving light measuring data measured in the camera body;

means for calculating exposure control data used for controlling exposure amount in accordance with the received light measuring data;

means for transmitting the calculated exposure control data towards the camera body; and

means for printing the calculated exposure control data on a film loaded in the camera body.