Advertisement
Inspection of Lens operations
Check the lens operations by using a personal computer after assembling.
○ Check by personal computer
● Check by the following considerations:
1. MR encoder operations
・Drive the scanning of lens and check the total number of pulses.
・In case the MR head of the MR encoder and the magnetic tape are misaligned, the number of pulses
becomes out of standard.
2. Lens-servo stop accuracy
・Check the number of overrun/underrun pulses (deviation of the stop position from the target position) per
the specified lens driving.
specified lens driving.
specified lens driving.
・In case the irregularity of mechanical operations does not take place in the focus ring driving unit, the
underrun tends to occur if it is heavy in the cam ring rotation of the MR encoder, while the overrun tends
to occur if it is light in its rotation of the MR encoder.
3. Lens-servo time
・Check the servo time (from starting and stopping the servo) when driving the specified lens by using the
oscilloscope.
・In case the irregularity of mechanical operations does not take place in the focus ring driving unit, the
servo-time tends to be long if it is heavy in the cam ring rotation of the MR encoder, while the servo-time
tends to be short if it is light in its rotation of the MR encoder.
4. Switches and lenses
・Check the ON/OFF operations of switches and the operating condition of the distance encoder.
● After inspections
1. When the MR encoder operations are not up to the standard:
Readjust the MR duty. (ref. Page A31.)
adjust the MR duty. (ref. Page A31.)
In case the pulse is not up to the standard, adjust the output waveform of the MR encoder again.
(ref. Page A12.)
In case the pulse meets the standard, replace the front fixed tube, focus tube unit, cam ring, etc.
2. When the lens-servo stop accuracy is not up to the standard:
Check the output waveform of the MR encoder. If it is normal, replace the front fixed tube , focus
tube unit, cam ring, etc.
3. When the lens-servo time is not up to the standard:
Readjust the driving frequency and motor control.
In case the lens-servo time is not up to the standard even after the readjustment, replace the front fixed
tube , focus tube unit, cam ring, etc.
4. When switches do not work properly:
Check the wiring state of the troubled switch or replace it.
ring rotation of the MR encoder, while the overrun tends
ring rotation of the MR encoder, while the overrun tends
ring rotation of the MR encoder, while the servo-time
ring rotation of the MR encoder, while the servo-time
- A33 ･ AF-S VR 70-300/4.5-5.6G -
INC
JAA79551-R.3690.A
Advertisement
