Patent US3801890A successfully refreshed from Google Patents.
US3801890A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Timer device and a camera using said device
Assignee: Canon Inc
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Filing: 1972-11-22
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Granted: 1974-04-02
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Expires: 1992-11-22
Abstract
Abstract A timer device is arranged for electrical connection to equipment to be controlled, such as a movie camera, including a source of potential, such as a battery in operative association with driving means such as an electric motor. The timing device includes a time constant circuit of the RC type in which the capacitor is charged solely from the battery or the like in the equipment. The equipment is of the type having a pair of remote control terminals controlling a supply circuit connecting the battery and the motor. The timer device has a pair of timer terminals arranged for connection to the remote control terminals, and a switching means, such as a transistor, is connected across the timer terminals so that, when the transistor is conductive, the supply circuit connecting the motor to the battery is closed. When a switch is operated, the capacitor means of the time constant circuit is charged, and the capacitor means discharges through the resistor means of the time constant circuit to apply a control current to the base of the transistor during the time required to discharge the capacitor means.
Inventors
- 👤 T Ichiyanagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:42
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/28; G; G03; G03B; G03B19/00; G03B19/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
192 words
A timer device, for electrical connection to equipment to be controlled and which equipment includeS a source of potential, a driving means connected to the source, a controlled mechanism coupled to the driving means and actuated thereby and a pair of remote control terminals included in a supply circuit connecting the driving means to the source, for remotely controlled energization of the driving means, said timer device comprising, in combination, a time constant circuit including resistor means connected to a first capacitor; a pair of timer terminals for connection to respective remote control terminals; switching means having a control element connected to said time constant circuit, said switching means being connected across the timer''s terminals for completion of said supply circuit when said control element is energized by discharge of said first capacitor; and means operable to connect said time constant circuit across said timer terminals for charging of said first capacitor solely by said source of potential in said equipment; said first capacitor discharging through said resistance means to supply a control current to said control element, so that said timer device controls connection of said driving means to said source.
Claim 2
Dependent Claim
192 words
A timer device, for electrical connection to equipment to be controlled and which equipment includeS a source of potential, a driving means connected to the source, a controlled mechanism coupled to the driving means and actuated thereby and a pair of remote control terminals included in a supply circuit connecting the driving means to the source, for remotely controlled energization of the driving means, said timer device comprising, in combination, a time constant circuit including resistor means connected to a first capacitor; a pair of timer terminals for connection to respective remote control terminals; switching means having a control element connected to said time constant circuit, said switching means being connected across the timer''s terminals for completion of said supply circuit when said control element is energized by discharge of said first capacitor; and means operable to connect said time constant circuit across said timer terminals for charging of said first capacitor solely by said source of potential in said equipment; said first capacitor discharging through said resistance means to supply a control current to said control element, so that said timer device controls connection of said driving means to said source.
Claim 3
Dependent Claim
82 words
A timer device, as claimed in claim 1, including a second capacitor connected to said first capacitor and charged by said first capacitor; a second resitance means forming a second time constant circuit with said second capacitor; a second switching means connected in the discharge circuit of said second capacitor and triggered conductive when the charged voltage of said capacitor attains a predetermined value; and means including said second switching means impressing the charge of said second capacitor on said first capacitor.
Claim 4
Dependent Claim
47 words
A timer device, as claimed in claim 1, including a second capacitor connected to said first capacitor and charged thereby; second switching means connected in the discharge circuit of said second capacitor; and means connecting said first capacitor to the control element of said second switching means.
Claim 5
Dependent Claim
43 words
A timer device, as claimed in claim 1, including constant voltage means connected to said first capacitor and maintaining the voltage applied thereto from said source of potential in the equipment at a constant value; said switching means comprising a Schmidt trigger circuit.
Claim 6
Dependent Claim
24 words
A timer device, as claimed in claim 1, including blocking diodes connected to both terminals of said first capacitor and preventing reverse current flow.
Claim 7
Dependent Claim
23 words
A timer device, as claimed in claim 1, including a luminous diode connected in parallel with said switching means and constituting an indicator.
Claim 8
Dependent Claim
49 words
A timer device, as claimed in claim 2, in which said second resistance means includes a variable resistor operable to adjust the conductance time of said second switching means whereby triggering conductive of said first-mentioned switching means is cyclically repeated at timed intervals controlled by said second switching means.
Claim 9
Dependent Claim
23 words
A timer device, as claimed in claim 3, in which said first-mentioned switching means comprises transistors connected to form a Darlington switching circuit.
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) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |