Patent US4566803A successfully refreshed from Google Patents.
← Back to Patent Explorer
US4566803A Expired / Lapsed US ⏱️ 0.0 years remaining

Power source off delay timer with liquid crystal display

Assignee: Omron Corp
•
Filing: 1984-09-26
•
Granted: 1986-01-28
•
Expires: 2004-09-26
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A power source off delay timer generates an off delay output after passage of a determinate time delay period from when an input power source is switched off. This timer includes a main body, a liquid crystal display mounted to the main body so as to display the operational condition of the timer, and a liquid crystal display drive unit for driving the liquid crystal display during the time that the power source is on and also during the determinate time delay period between the time instant at which the power source is switched off and the subsequent time instant at which the timer generates the off delay output. Thereby, the position of the liquid crystal display may be substantially arbitrarily selected, and also the position of the keep relay may be arbitrarily chosen. And because the liquid crystal display and also the drive unit therefore have typically very low power consumptions, it is possible to keep them in operation without exhausting the power source such as a capacitor for operating the timer after the power source has been switched off, even if the delay time period is very long. A variable resistor may be used for adjusting the time delay period; and the system may include a flasher circuit for flashing the liquid crystal display, to make its indication even more visible.

Inventors

  • 👤 Tetuya Waniisi
  • 👤 Hiroshi Sato
  • 👤 Isao Nanba

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 22:31
CPC Classifications
G; G04; G04F; G04F1/00; G04F1/005

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 110 words
A power source off delay timer, for generating an off delay output after passage of a determinate time delay period from when an input power source is switched off, comprising: (a) a main body; (b) a liquid crystal display mounted to said main body so as to display the operational condition of said timer; and (c) a liquid crystal display drive unit for driving said liquid crystal display during the time that said power source is on and also during said determinate time delay period between the time instant at which said power source is switched off and the time instant at which said timer generates said off delay output.
Claim 2
Dependent Claim 110 words
A power source off delay timer, for generating an off delay output after passage of a determinate time delay period from when an input power source is switched off, comprising: (a) a main body; (b) a liquid crystal display mounted to said main body so as to display the operational condition of said timer; and (c) a liquid crystal display drive unit for driving said liquid crystal display during the time that said power source is on and also during said determinate time delay period between the time instant at which said power source is switched off and the time instant at which said timer generates said off delay output.
Claim 3
Dependent Claim 24 words
A power source off delay timer according to claim 1, further comprising a variable resistance whose set value determines said determinate time delay period.
Claim 4
Dependent Claim 76 words
A power source off delay timer according to claim 1, further comprising a timer circuit which outputs a drive on signal to said liquid crystal display drive unit to cause it to drive said liquid crystal display, during said determinate time delay period between the time instant at which said power source is switched off and the time instant at which said timer generates said off delay output, and which times said determinate time delay period.
Claim 5
Dependent Claim 32 words
A power source off delay timer according to claim 3, further comprising a variable resistance whose set value determines the value of said determinate time delay period timed by said timer circuit.
Claim 6
Dependent Claim 26 words
A power source off delay timer according to claim 1, further comprising a flasher circuit for flashing said liquid crystal display when it is being driven.

References Cited (Backward Citations)

US3641545A Cited
US3678499A Cited
US3753001A Cited
US3750123A Cited
US3968417A Cited
US4189649A Cited
US4404624A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-01-27 1989-07-29 1990-01-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-01-27 1993-07-29 1994-01-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-01-27 1997-07-29 1998-01-28 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag