Cyclically operable optical shutter

Claim 2

A cyclically operable optical shutter comprising: A. means defining a radiation transmitting aperture having an optics axis; B. an occulting disk including means defining therein a pair of radiation occulting sectors and a radiation transmitting sector interposed between the occulting sectors; C. means abaxially related to said aperture supporting said disk for oscillatory rotation in a plane disposed in close proximity to said aperture and normally related to said optics axis, whereby said sectors sequentially are caused to traverse the aperture as the disk is driven in oscillatory rotation; D. cyclically energizable means coupled with said disk for angularly accelerating the disk from zero velocity to a selected steady-state angular velocity, as a first occulting sector is caused to traverse said aperture, maintaining said steady-state angular velocity for said disk as the radiation transmitting sector traverses said aperture, and thereafter decelerating said disk to a zero velocity as a second occulting sector is caused to traverse said aperture, whereby during each cycle of operation a radiation transmitting sector is caused to traverse said aperture at a constant velocity for providing a pulse of radiation having an accurately predictable width; and E. a counter rotor operatively coupled with said support means for applying thereto reaction torque in a direction and with a magnitude sufficient for countering reaction torque responsively applied to the support as a consequence of the oscillatory rotation imparted to said disk.

Claim 3

The shutter of claim 1 wherein the disk further includes means defining another radiation transmitting sector interposed between said pair of radiation occulting sectors in diametric opposition to the first mentioned radiation transmitting sector.

Claim 4

The shutter of claim 2 wherein said occulting sectors are defined by circumscribing surfaces of equal dimensions while said transmitting sectors are defined by surfaces of unequal dimensions.

Claim 5

The shutter of claim 2 wherein said transmitting sectors comprise truncated portions of the occulting disk.

Claim 6

The shutter of claim 3 wherein one of said sectors is defined between surfaces having a projected included angle of 80* while the other transmitting sector is defined between surfaces having a projected included angle of 5* for thereby providing a wide and a narrow radiation transmitting sector.

Claim 7

An optical shutter comprising: A. a mounting plate; B. a means defining an aperture in the mounting plate; C. an occulting disk including a pair of diametrically related, radiation transmitting sectors and a pair of occulting sectors interposed between the radiation transmitting sectors; D. means mounting said disk on said mouNting plate for rotation in a plane parallel to the plane of the aperture and in a manner such that the transmitting sectors and the occulting sectors alternately traverse said aperture as the disk is rotated, whereby pulsed radiation is gated through said aperture; E. drive means including an electrically energizable motor coupled with said occulting disk for imparting selected fractional turns of rotation to said disk; F. control means coupled with said drive means including a ramp generator for providing a reference signal indicative of selected instantaneous angular dispositions to be imposed on said disk as rotation is imparted thereto; G. a bank of potentiometers including means for delivering an output signal indicative of instantaneous angular dispositions imposed on the disk as it is driven in rotation; H. a D.C. power amplifier coupled with said ramp generator and said bank of potentiometers for receiving and electrically summing signals delivered thereto from the ramp generator and said bank potentiometers and for delivering an output voltage to said drive means for causing said drive means to correct position error operationally established between the instantaneous angular dispositions imposed on said disk and the selected instantaneous dispositions to be imposed on said disk; and I. a tachometer coupled with said drive means and said power amplifier for delivering a damping voltage to said power amplifier.

Claim 8

An optical shutter comprising: A. a mounting plate; B. a means defining an aperture in the mounting plate; C. an occulting disk including a pair of diametrically related, radiation transmitting sectors and a pair of occulting sectors interposed between the radiation transmitting sectors; D. means mounting said disk on said mouNting plate for rotation in a plane parallel to the plane of the aperture and in a manner such that the transmitting sectors and the occulting sectors alternately traverse said aperture as the disk is rotated, whereby pulsed radiation is gated through said aperture; E. drive means including an electrically energizable motor coupled with said occulting disk for imparting selected fractional turns of rotation to said disk; F. control means coupled with said drive means including a ramp generator for providing a reference signal indicative of selected instantaneous angular dispositions to be imposed on said disk as rotation is imparted thereto; G. a bank of potentiometers including means for delivering an output signal indicative of instantaneous angular dispositions imposed on the disk as it is driven in rotation; H. a D.C. power amplifier coupled with said ramp generator and said bank of potentiometers for receiving and electrically summing signals delivered thereto from the ramp generator and said bank potentiometers and for delivering an output voltage to said drive means for causing said drive means to correct position error operationally established between the instantaneous angular dispositions imposed on said disk and the selected instantaneous dispositions to be imposed on said disk; and I. a tachometer coupled with said drive means and said power amplifier for delivering a damping voltage to said power amplifier.

Claim 9

The shutter of claim 6 wherein means including a counter-rotor operatively is coupled with said mounting plate for cancelling reaction torque developed and applied to said mounting plate by said drive means.

Claim 10

The shutter of claim 7 wherein said counter-rotor includes a motor and an operatively associated dummy fly-wheel driven simultaneously in opposition to said disk and at rates coincident therewith.