System for driving a movable stage

A system for controlling the rotation of a motor depending on the drive voltage applied thereto, said system comprising:

• (a) first generator means for generating a pulse;
• (b) second generator means for generating a pulse in response to a predetermined rotation in said motor;
• (c) means for counting the number of pulses from said first and second generator means, said counting means being adapted to generate a signal indicative of a difference between the number of pulses from said first generator means and the number of pulses from said second generator means;
• (d) means for forming a sawtooth pulse;
• and
• (e) means responsive to said sawtooth pulse to form said drive voltage, the last-mentioned means being adapted to control said drive voltage in accordance with the signal from said counting means.

A stage driving system having optical means providing a plurality of magnifications for observing an object on a stage and an operation lever tiltable from its neutral position in all the directions, said stage being moved in two-dimensional direction depending on the direction of the tilted operation lever, said system comprising:

• (a) means for detecting the angle of the tilted operation lever from its neutral position, said detecting means being adapted to generate a first detection output signal corresponding to the angle of the tilted operation lever from its neutral position;
• (b) means responsive to said first detection signal to move said stage in two-dimensional plane at a velocity corresponding to the angle of the tilted operation lever;
• (c) means for detecting the magnification of said optical means to generate a second detection signal;
• and
• (d) means responsive to said second detection signal to control the velocity of said moving stage provided by said moving means depending on the angle of the tilted operation angle.

A system for controlling the rotation of a motor in accordance with a drive voltage, said system comprising:

• (a) first generator means for generating a pulse;
• (b) second generator means for generating a pulse in accordance with a predetermined rotation in said motor;
• (c) means for counting the number of pulses from said first and second generator means, said counting means being adapted to generate a digital output signal indicative of a difference between the number of pulses from said first generator means and the number of pulses from said second generator means;
• (d) means for forming a sawtooth pulse;
• and
• (e) converter means for converting said digital signal into an analog signal which in turn is outputted as said drive voltage, said converter means being adapted to control said drive voltage in accordance with said sawtooth pulse.