Polaroid ProCam Repair Manual page 19

At the same time, the Transducer Ranging Circuit is determining the distance from
camera to subject. When the encoder count reaches a point which corresponds to
the subject distance, a signal is sent to activate Solenoid 2. Activation of Solenoid
2 causes the Catch Pawl to engage the teeth along the edge of the Quintic sector.
The Quintic sector is thus halted when the portion of the lens which optically
corresponds to the subject distance is positioned behind the Taking Lens. At this
point, Solenoid 1 is de-energized, releasing the Walking Beam. The Opening Blade
Spring pulls the Walking Beam in a counterclockwise direction and the Shutter
Blades open.
When the exposure is completed, Solenoid 1 is again energized, pulling in the
Walking Beam and closing the Shutter Blades. Solenoid 2 then releases, allowing
the Quintic Return Spring to force the Quintic sector to return to its original
setting. This action also causes the Catch Pawl to engage the Walking Beam,
latching it in position. Thus, when Solenoid 1 is de-energized, all the components
are in the same position they were in before the exposure cycle started.
RANGING
CIRCUIT
ENCODER
CIRCUIT
PHOTOTRANSISTOR
Figure 1-11. Encoder Circuit Detects LED Light Pulses
Figure 1-12. Catch Pawl Stops Quintic Lens rotation
CUTOUTS IN QUINTIC
FRAME PULSE LED
BEAM
SOLENOID 2
ENERGIZED
1 - 13
LED
CATCH PAWL
QUINTIC LENS
QUINTIC LENS
STOPPED