Light control device

• US 4,041,512 A
• Filed: 02/18/1975
• Issued: 08/09/1977
• Est. Priority Date: 02/22/1974
• Status: Expired due to Term

• Current Assignee: West Electric Company Limited
• Original Assignee: West Electric Company Limited
• Inventors: Iwata, Hiroshi, Ishikawa, Katsuji
• Primary Examiner(s): Adams, Russell E.
• Application Number:
  US05/550,544
• Time in Patent Office: 903 Days
• Field of Search: 354/23 D, 354/60 R, 354/60 A, 354/234, 354/235, 354/238, 354/40, 354/38, 354/50, 354/271
• US Class Current: 396/449
• CPC Class Codes: G03B 7/085 for control of aperture

Abstract

The invention discloses a light control device comprising a light control mechanism comprising a plurality of shutter blades, which may also function as an aperture control diaphragm, and shutter blade driving means for intermittently driving the shutter blades in response to pulse signals; and a control circuit for applying the pulse signals to the driving means.

Claims

1. A light control device comprising:

A. a light control mechanism comprising

a. shutter blade means drivable to a plurality of positions for defining at each position a different aperture, and

b. shutter blade driving means connected to said shutter blade means for driving said shutter blade means to successive positions in response to each pulse of a first pulsatory signal and for controlling the direction of driving said shutter blade means in response to each pulse of a second pulsatory signal,

B. a control circuit for providing said pulsatory signals comprising,

a. a rectangular pulse generator for generating driving pulse signals and having an output terminal,

b. circuit means connected to said pulse generator for selectably controlling the number of pulses applied to said output terminal of said pulse generator,

c. circuit means responsive to said pulses at said output terminal for producing said first pulsatory signal, and

d. circuit means continuously responsive to said pulses at said output terminal for producing said second pulsatory signal, whereby said second pulsatory signal may occur a plurality of times for a selected number of pulses at said output terminal.

2. A light control device as set forth in claim 1 wherein

said pulse generator includes means for selectively changing the pulse spacing of the pulses generated by said generator.

3. A light control device as recited in claim 1, wherein said rectangular pulse generator comprises

A. signal transmission means comprising

a. signal transmitter means for transmitting remote control signals, and

b. signal receiver means located at a remote place from said transmitter means for receiving said remote control signals, and

B. signal converter means for generating electrical pulse signals of rectangular waveform in response to the remote control signals received by said receiver means.

4. A light control device as set forth in claim 3 wherein said transmitter means comprises means for transmitting the control signal by electromagnetic waves.

5. A light control device as set forth in claim 3 wherein said transmitter means comprises means for transmitting the control signal by a light beam.

6. A light control device as set forth in claim 3 wherein said transmitter means comprises means for transmitting the control signal by sound.

7. A light control device as set forth in claim 1, wherein said circuit means for selectively controlling the number of pulses applied to said output terminal comprises means for manually setting the number of pulses generated by said pulse generator.

8. A light control device as set forth in claim 7 wherein

said pulse generator includes means for selectively changing the pulse spacing of the pulses generated by said generator.

9. A light control device as set forth in claim 8 further comprising a circuit for controlling the "on" time of said means for selectively controlling the number of pulses in response to the pulse spacing of the pulses generated by said pulse generator.

10. The light control device of claim 1 wherein said circuit means responsive to pulses at said output terminal for producing said first pulsatory signal comprises a driving pulse generator having a repetition rate that is a multiple of the repetition rate of said rectangular pulse generator, whereby driving pulses for said shutter blade driving means have a repetition rate that is a multiple of the pulses at said output terminal.

11. The light control mechanism of claim 10 wherein said circuit means responsive to said pulses at said output terminal comprises means applying said pulses at said output terminal to said shutter blade driving means for reversing the drive direction of said shutter blade driving means at the repetition rate of the pulses at said output terminal.

12. The light control device of claim 10 wherein said driving pulse generator has a manually adjustable pulse repetition rate.

13. The light control mechanism of claim 1 wherein said circuit means for producing said first pulsatory signal comprises delay means, whereby signal transitions of said first pulsatory signal are separated from signal transitions of said second pulsatory signal.

14. A light control device comprising a light control mechanism, said light control mechanism comprising shutter blade means for defining an aperture, and stepping motor means connected to drive said shutter blade means;

and a control circuit for said stepping motor means, said control circuit comprising a pulse generator for generating drive pulse signals, a pulse number selection circuit connected to apply a predetermined number of said pulse signals from said pulse generator to said stepping motor means for stepping said stepping motor means, and a direction control circuit connected to said stepping motor means for controlling said stepping motor means to step in one direction at least once and to subsequently step in the opposite direction, said direction control circuit being connected to be continuously responsive to pulse signals received from said pulse number selection circuit whereby the number of reversals of said stepping motor means in any cycle of a predetermined number of pulse signals is dependent upon said predetermined number;

said shutter blade means comprising a pair of pivotally mounted shutter blades pivoted at a common axis, each said blade having an arcuate surface, said arcuate surfaces comprising arcuate slots in respective ends of said shutter blades away from said common axis, a separate drive means coupled from said stepping motor means to each of said surfaces, said separate drive means comprising separate pins extending into said slots and coupled to be driven by said stepping motor means, whereby said shutter blades pivot in opposite relative directions about their pivotal axes in response to stepping of said stepping motor means, said shutter blades each having a notch between said common axis and the arcuate slot thereof positioned to define an opening between said blades at one angular displacement of said stepping motor means, said blades blocking said opening at another angular displacement on said stepping motor means.

15. A light control device comprising a light control mechanism, said light control mechanism comprising shutter blade means for defining an aperture, and stepping motor means connected to drive said shutter blade means;

and a control circuit for said stepping motor means, said control circuit comprising a pulse generator for generating drive pulse signals, a pulse number selection circuit connected to apply a predetermined number of said pulse signals from said pulse generator to said stepping motor means for stepping said stepping motor means, and a direction control circuit connected to said stepping motor means for controlling said stepping motor means to step in one direction at least once and to subsequently step in the opposite direction, said direction control circuit being connected to be continuously responsive to pulse signals received from said pulse number selection circuit so that said stepping motor means may undergo a plurality of reversals in any cycle of a predetermined number of pulse signals, dependent upon said predetermined number;

said shutter blade means comprising a pair of pivotally mounted shutter blades, each said blade having an arcuate surface, a separate drive means coupled from said stepping motor means to each of said surfaces whereby said shutter blades pivot in opposite relative directions about their pivotal axes in response to stepping of said stepping motor means, said shutter blades each having a cutout positioned to define an opening between said blades at one angular displacement of said stepping motor means, said blades blocking said opening at another angular displacement on said stepping motor means.

16. The light control device of claim 15 wherein said shutter blades are pivoted at a common axis.

17. The light control device of claim 16 wherein said arcuate surfaces comprise arcuate slots in respective ends of said shutter blades away from said common axis, said separate drive means comprising separate pins extending into said slots and coupled to be driven by said stepping motor means.

18. A light control device comprising a light control mechanism, said light control mechanism comprising shutter blade means for defining an aperture, and stepping motor means connected to drive said shutter blade means;

and a control circuit for said stepping motor means, said control circuit comprising a pulse generator for generating drive pulse signals, a pulse number selection circuit connected to apply a predetermined number of said pulse signals from said pulse generator to said stepping motor means for stepping said stepping motor means, and a direction control circuit connected to said stepping motor means for controlling said stepping motor means to step in one direction at least once and to subsequently step in the opposite direction, said direction control circuit being connected to be continuously responsive to pulse signals received from said pulse number selection circuit so that said stepping motor means may undergo a plurality of reversals in any cycle of said predetermined number of pulse signals, dependent upon said predetermined member, said shutter blade means comprising a stationary ring, a rotatable ring coaxial with said stationary ring, a plurality of shutter blades extending normal to said rings, and being pivotally coupled to one of said rings, means coupled to the other of said rings for rotating each of said blades about its pivotal axis whereby said blades define an aperture coaxial with said rings, said aperture being closed in one relative angular displacement of said rotatable ring, and means coupling said stepping motor means to rotate said rotatable ring.

19. The light control device of claim 18 wherein said shutter blades are pivoted to said stationary ring, said rotatable ring is rotatable within said stationary ring, each of said shutter blades having a slot, and pin means on said rotatable ring extending into separate said slots for rotating the respective shutter blades.

20. The light control device of claim 19 wherein said stepping motor has a rotor with an axially extending hole, said rotor being mounted coaxially with said rotatable ring and coupled to drive said rotatable ring, whereby the opening defined by said shutter blades is coaxial with said rotor.

21. The light control device of claim 18 wherein said stepping motor means has a central rotor with a hole extending axially therethrough, said rotor being mounted coaxially with said rotatable ring and coupled to drive said rotatable ring, whereby said opening defined by said shutter blades is coaxial with said rotor.