Film cartridges, films and cameras adapted for use therewith

• US 5,146,249 A
• Filed: 01/24/1991
• Issued: 09/08/1992
• Est. Priority Date: 06/08/1981
• Status: Expired due to Term

• Current Assignee: Minolta Camera Kabushiki Kaisha
• Original Assignee: Minolta Camera Kabushiki Kaisha
• Inventors: Taniguchi, Nobuyuki, Hoda, Takeo, Seigenji, Kiyoshi
• Primary Examiner(s): Hix, L. T.
• Assistant Examiner(s): Gray, David M.
• Application Number:
  US07/645,499
• Time in Patent Office: 593 Days
• Field of Search: 354/21, 352/78 C
• US Class Current: 396/208
• CPC Class Codes: G03B 7/24 automatically in accordance with markings or other means indicating film speed or kind of film on the magazine to be inserted in the camera

Abstract

Disclosed are film cartridges having improved digital code patterns, films having improved digital signal means, and cameras adapted for use with the film cartridges or the films. The improved code patterns include bits with different weights and a bit which is made conductive with at least one of the bits with the different weights.

One of the cameras disclosed is provided with a reading device on a spool so that the reading device can continuously read the signal means at a front tip of a leader portion of the film throughout the duration in which the film is wound around the spool. Another camera disclosed is adapted to read the code patterns on the film cartridge upon insertion of the film cartridge into a cartridge chamber. Various camera circuits are proposed, in one of which decimal or fractional APEX values of read film speeds are converted to outputs with weights of 1/2, 1/4 and 1/8 for digital calculation and in another of which film speeds divided by 1/3 Ev steps are automatically set by being grouped into one of high, middle and low film speed ranges.

Claims

1. In a camera adapted for use with a film cartridge having a code pattern in accordance with the APEX values Sv of film speed of a film contained in said film cartridge, a code detection device comprising:

means for reading the code pattern to generate a first signal indicative of the film speed represented by said code pattern;

means for detecting whether or not the film cartridge has a code pattern in response to said first signal;

means for manually setting a film speed to generate a second signal indicative of the manually set film speed;

means for changing the operation mode by a manual operation between a first operation mode in which said first signal is to be used and a second operation mode in which said second signal is to be used;

means for displaying the film speed corresponding to the signal which is to be used in response to the operation mode changed by said changing means; and

indicating means controlled in the first operation mode to be in a first indication condition when it is detected that a film cartridge loaded in the camera has the code pattern and controlled to be in a second indication condition when it is detected that the film cartridge loaded in the camera does not have the code pattern in the first operation mode to indicate that the loaded film does not have this code pattern although the operating mode is selected to be the first operation mode.

2. A code detection device as stated in claim 1, wherein the second signal is used when it is detected that the film loaded in the camera does not have the code pattern in the second operation mode.

3. A code detection device as stated in claim 1, wherein said indicating means indicates that the first signal is used as a film speed under the first indication condition and the second signal is used as a film speed under the second indication condition.

4. A code detection device as claimed in claim 1 wherein said indicating means indicates a character identifying the automatic mode in the first indication condition and indicates a character showing the manual mode in the second indication condition.