Patent US3876288A successfully refreshed from Google Patents.
US3876288A
Expired / Lapsed
US
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Light controlling device
Assignee: West Electric Co Ltd
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Filing: 1973-09-06
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Granted: 1975-04-08
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Expires: 1993-09-06
Abstract
Abstract A light controlling device comprising a magnetic colloidal fluid formed of a mixture of pulverized active magnetic material consisting of a magnetic metal such as nickel, cobalt, iron, etc. or an iron oxide and oleic acid, heptane, etc. sealed in a vessel with a transparent material such as glycerin, silicone oil, etc. A magnetic field can be applied from the outside of said vessel to control the position of said magnetic fluid. Thereby, the device may serve as a light shutter or diaphragm.
Inventors
- 👤 Hiroshi Iwata
- 👤 Tetsuo Yamaoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:15
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/09; G02F1/091; G03; G03B; G03B9/00; G03B9/58
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
183 words
A light exposure controlling device, comprising: a sealed vessel containing a first colloidal magnetic fluid including an active magnetic material in suspension, and a second transparent fluid which is immiscible with said magnetic fluid, the volume ratio of said fluids corresponding to a desired area of transparency for transmitting electro-magnetic radiation through said vessel; magnetic field generating means coupled to said sealed vessel for generating a magnetic field to change the relative positions of said first and second fluids in said sealed vessel between transmitting and non-transmitting positions, said magnetic field generating means comprising core means, and an electro-magnetic coil wound around said core means, said core means having an opening through which electro-magnetic radiation passes and which is spatially located in correspondence with the location of said second fluid in its transmitting position to allow transmission through said vessel of said electro-magnetic radiation; and means for supplying electrical energy to said magnetic field generating said magnetic field to cause said first and second fluids to shift positions relative to each other and to permit transmission of said electro-magnetic radiation through said vessel.
Claim 2
Dependent Claim
183 words
A light exposure controlling device, comprising: a sealed vessel containing a first colloidal magnetic fluid including an active magnetic material in suspension, and a second transparent fluid which is immiscible with said magnetic fluid, the volume ratio of said fluids corresponding to a desired area of transparency for transmitting electro-magnetic radiation through said vessel; magnetic field generating means coupled to said sealed vessel for generating a magnetic field to change the relative positions of said first and second fluids in said sealed vessel between transmitting and non-transmitting positions, said magnetic field generating means comprising core means, and an electro-magnetic coil wound around said core means, said core means having an opening through which electro-magnetic radiation passes and which is spatially located in correspondence with the location of said second fluid in its transmitting position to allow transmission through said vessel of said electro-magnetic radiation; and means for supplying electrical energy to said magnetic field generating said magnetic field to cause said first and second fluids to shift positions relative to each other and to permit transmission of said electro-magnetic radiation through said vessel.
Claim 3
Dependent Claim
49 words
the apparatus according to claim 1, further comprising an optical lens formed in one wall portion of said sealed vessel at a location corresponding to the location to which said second fluid is moved upon energizing said magnetic field generating means for transmitting said electro-magnetic radiation through said vessel.
Claim 4
Dependent Claim
38 words
A light exposure controlling device according to claim 1, wherein said core is split into a multiplicity of portions separated by a multiplicity of nonmagnetic members and each of the split portions is provided with an electromagnetic coil.
Claim 5
Dependent Claim
33 words
A light exposure controlling device according to claim 2, further comprising: a lens disposed in the neighborhood of said sealed vessel; and a photosensitive material disposed in the neighborhood of said sealed vessel.
Claim 6
Dependent Claim
32 words
A light exposure controlling device according to claim 1, wherein said power supply means includes a time setting circuit for setting the time for supplying the electric energy to said electromagnetic coil.
Claim 7
Dependent Claim
77 words
A light exposure control device according to claim 5, wherein said time setting circuit comprises a D.C. power source, a plurality of storage capacitors of different storage capacities, means for selectivity coupling said capacitors to said D.C. power source and to said magnetic field generating means, and a control element coupled to said magnetic field generating means for selectively opening and closing the conduction path between said magnetic field generating means and said power source and capacitors.
Claim 8
Dependent Claim
57 words
A light exposure controlling device according to claim 5, wherein said time setting circuit comprises a variable D.C. voltage source, a capacitor connected in parallel with said D.C. voltage source for supplying the electric energy to said electro-magnetic coil, and a controlling element for opening and closing the conduction path from said capacitor to said electromagnetic coil.
Claim 9
Dependent Claim
58 words
A light exposure controlling device according to claim 5, wherein said time setting circuit comprises a D.C. source, a voltage divider for dividing the voltages of said D.C. source and for supplying the divided voltages to said electromagnetic coil, and a control element for opening and closing the conduction path from said voltage divider to said electro-magnetic coil.
Claim 10
Dependent Claim
25 words
A light exposure controlling device according to claim 1, wherein a plurality of said magnetic field generating means is disposed to surround said sealed vessel.
Claim 11
Dependent Claim
34 words
A light exposure device according to claim 9, further comprising means for varying the distribution of the magnetic field applied to said sealed vessel for rapidly moving said magnetic fluid to the non-transmitting state.
Claim 12
Dependent Claim
51 words
A light exposure device according to claim 9, further comprising a secondary magnetic field generating means coupled to said sealed vessel in addition to a plurality of primary ones of said magnetic field generating meand disposed to surround said sealed vessel, for rapidly moving the magnetic fluid to the non-transmitting position.
Claim 13
Dependent Claim
144 words
A light exposure controlling device, comprising: a sealed vessel containing a first colloidal magnetic fluid including an active magnetic material in suspension, and a second transparent fluid which is immiscible with said magnetic fluid, the volume ratio of said fluids corresponding to a desired area of transparency for transmitting electro-magnetic radiation through said vessel; magnetic field generating means coupled to said sealed vessel for generating a magnetic field to change the relative positions of said first and second fluids in said sealed vessel between transmitting and non-transmitting positions, said magnetic field generating means comprising an electro-magnetic coil wound around said sealed vessel; and means for supplying electrical energy to said magnetic field generating means to generate said magnetic field to cause said first and second fluids to shift positions relative to each other and to permit transmission of said electro-magnetic radiation through said vessel.
Claim 14
Dependent Claim
144 words
A light exposure controlling device, comprising: a sealed vessel containing a first colloidal magnetic fluid including an active magnetic material in suspension, and a second transparent fluid which is immiscible with said magnetic fluid, the volume ratio of said fluids corresponding to a desired area of transparency for transmitting electro-magnetic radiation through said vessel; magnetic field generating means coupled to said sealed vessel for generating a magnetic field to change the relative positions of said first and second fluids in said sealed vessel between transmitting and non-transmitting positions, said magnetic field generating means comprising an electro-magnetic coil wound around said sealed vessel; and means for supplying electrical energy to said magnetic field generating means to generate said magnetic field to cause said first and second fluids to shift positions relative to each other and to permit transmission of said electro-magnetic radiation through said vessel.
Claim 15
Dependent Claim
49 words
The apparatus according to claim 12, further comprising an optical lens formed in one wall portion of said sealed vessel at a location corresponding to the location to which said second fluid is moved upon energizing said magnetic field generating means for transmitting said electro-magnetic radiation through said vessel.
Claim 16
Dependent Claim
66 words
The apparatus according to claim 12, wherein said coil comprises a plurality of intermediate taps; the apparatus further comprising means for selectively coupling said supply means to said taps to thereby control the magnetic field distribution in said vessel to selectively displace said first fluid in correspondence with the field distribution to control the area of transparency for the transmission of electro-magnetic radiation through said vessel.
Claim 17
Dependent Claim
32 words
A light exposure controlling device according to claim 12, wherein said power supply means includes a time setting circuit for setting the time for supplying the electric energy to said electromagnetic coil.
Claim 18
Dependent Claim
77 words
A light exposure control device according to claim 15, wherein said time setting circuit comprises a D.C. power source, a plurality of storage capacitors of different storage capacities, means for selectively coupling said capacitors to said D.C. power source and to said magnetic field generating means, and a control element coupled to said magnetic field generating means for selectively opening and closing the conduction path between said magnetic field generating means and said power source and capacitors.
Claim 19
Dependent Claim
57 words
A light exposure controlling device according to claim 15, wherein said time setting circuit comprises a variable D.C. voltage source, a capacitor connected in parallel with said D.C. voltage source for supplying the electric energy to said electro-magnetic coil, and a controlling element for opening and closing the conduction path from said capacitor to said electromagnetic coil.
Claim 20
Dependent Claim
58 words
a light exposure controlling device according to claim 15, wherein said time setting circuit comprises a D.C. source, a voltage divider for dividing the voltage of said D.C. source and for supplying the divided voltages to said electromagnetic coil, and a control element for opening and closing the conduction path from said voltage divider to said electro-magnetic coil.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |