Browse Prior Art Database

Automatic Load Unload of a Camera

IP.com Disclosure Number: IPCOM000081298D
Original Publication Date: 1974-May-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 5 page(s) / 50K

Publishing Venue

IBM

Related People

Deskevich, S: AUTHOR [+2]

Abstract

The system shown in block diagram form provides for automatic loading and unloading of a camera without exposing any film during the process. It also provides for automatic recovery for power on-off situations.

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Automatic Load Unload of a Camera

The system shown in block diagram form provides for automatic loading and unloading of a camera without exposing any film during the process. It also provides for automatic recovery for power on-off situations.

The basic load-unload control logic is designated by reference character 1. A delay counter 2 is used to produce the various time delays to check for correct operation of the various load-unload sequences. A sequence ring 3 controls the various load-unload sequences. Block 4 is the supply motor analog control card. Block 5 is the take-up motor analog control card. Block 6 is the supply motor. Block 7 is the take-up motor. Block 8 is the supply column capacitive sensor. Block 9 is the take-up column capacitive sensor.

The camera employs a DC servo system film drive with capacitive sensors as the feedback element in the servo loop. Film sensing during loading is accomplished optically using infrared light-emitting diodes (LED's) and phototransistor detectors. Limit switches are employed in determining various states of the movable camera parts. AUTOMATIC LOADING:.

Having installed a cassette, the camera is ready for loading. A load button, not shown, is depressed to supply a signal on line 11 to logic 1, thence to controls 4 and supply motor 6, and the supply motor is energized to drive film from the supply reel in a clockwise (CW) direction. The motor 6 drives a loop of film into the camera which is utilized as a load vacuum column for loading and unloading. The loop of film is optically detected before it reaches the bottom of the column. The drive to the supply motor 6 is then switched off and a low voltage drive is applied to the take-up motor 7. This voltage is calculated to be such that the force applied to the film by the take-up motor 7 balances the force applied to the film by the vacuum in the load column. Thus the film loop will be maintained in the load column.

As the supply motor 6 was driving the loop of film into the camera, a time delay was activated by starting the delay counter 2. If the film is not detected in the load column prior to a specified time delay, the load cycle is halted and indicated as such. This is to prevent continual film drive from the supply in the event of a film jam.

After the loop has been detected in the load column, the sequence ring 3 is advanced to Seq. 1. At Seq. 1 time, a mobile film transport solenoid is de- energized and the film transport along with the lens mount, none of which are shown, will move forward around the film. When the film transport is completely forward, the lens mount will close on the film. After detecting the lens mount as being closed by sampling a limit switch, the sequence ring 3 is advanced to Seq.
2. At Seq. 2 time, the load vacuum column solenoid will be de-energized and the take-up motor 7 will begin to draw the loop out of the load column and around the film transport.

The delay counter 2 is started again at Seq. 2 t...