Patent US4723836A successfully refreshed from Google Patents.
US4723836A
Expired / Lapsed
US
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Handwritten character input device
Assignee: Sharp Corp
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Filing: 1984-10-10
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Granted: 1988-02-09
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Expires: 2004-10-10
Abstract
Abstract A handwritten character input device includes an opaque tablet or digitizer for inputting a handwritten character or figure into an apparatus. The tablet is of an electromagnetic induction type. The tablet is positioned under a liquid crystal display panel and an aluminum-evaporated film reflector is provided for the liquid crystal display. Preferably, the aluminum-evaporated film reflector is as thick as 1.0 micron or less. A conductive shield plate may be further provided between the tablet and a driving circuit substrate for the liquid crystal display panel. This shield plate serves to magnetically isolate the tablet from the driving substrate.
Inventors
- 👤 Yoshio Kono
- 👤 Yukihiro Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:59
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/041; G06F3/0412; G06F3/046
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
142 words
A handwritten character input device comprising: exciting means for exciting and inputting character information by hand-writing a character; electromagnetic induction tablet means, responsive to said exciting means, for sensing the character inputted by said exciting means, said electromagnetic induction tablet being opaque; liquid crystal display panel means, responsive to the detection of said electromagnetic induction tablet means, for displaying the inputted character; and an aluminum-evaporated film reflector serving to reflect radiation toward said liquid crystal display panel means, said aluminum-evaporated film reflector being disposed between said liquid cyrstal display panel and said electromagnetic induction tablet means and having a thickness of 1.0 micron or less; wherein said exciting means comes in contact with a first top side of said liquid crystal display means with said electromagnetic induction tablet means being positioned beneath a second, bottom side of said liquid crystal display means.
Claim 2
Dependent Claim
142 words
A handwritten character input device comprising: exciting means for exciting and inputting character information by hand-writing a character; electromagnetic induction tablet means, responsive to said exciting means, for sensing the character inputted by said exciting means, said electromagnetic induction tablet being opaque; liquid crystal display panel means, responsive to the detection of said electromagnetic induction tablet means, for displaying the inputted character; and an aluminum-evaporated film reflector serving to reflect radiation toward said liquid crystal display panel means, said aluminum-evaporated film reflector being disposed between said liquid cyrstal display panel and said electromagnetic induction tablet means and having a thickness of 1.0 micron or less; wherein said exciting means comes in contact with a first top side of said liquid crystal display means with said electromagnetic induction tablet means being positioned beneath a second, bottom side of said liquid crystal display means.
Claim 3
Dependent Claim
35 words
The device of claim 1, further comprising: a substrate carrying driving circuitry that drives said liquid crystal display panel means; and a conductive shield plate positioned between said electromagnetic induction table means and said substrate.
Claim 4
Dependent Claim
72 words
The device of claim 1 wherein said liquid crystal display panel means comprises: a first polarizer, forming said first top side of said liquid crystal display panel means; a first glass substrate and a second glass substrate disposed beneath said first polarizer, and sealing a liquid crystal layer; and a second polarizer, disposed beneath said first and second glass substrates, forming said second bottom side of said liquid crystal display panel means.
Claim 5
Dependent Claim
47 words
The device of claim 3 wherein said first polarizer has a thickness of approximately 200 microns, said first and second substrates each have a thickness of approximately 0.7 millimeters and said second polarizer and said aluminum evaporated film reflector have a combined thickness of approximately 230 microns.
Claim 6
Dependent Claim
65 words
The device of claim 3 further comprising: driving means for activating said liquid crystal display means, said driving means being disposed on a third substrate, said third substrate being positioned such that said electromagnetic induction table means is between said liquid crystal display panel means and said third substrate; and a conductive shield plate disposed between said third substrate and said electromagnetic induction tablet means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-08 | 1991-08-10 | 1992-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-08 | 1995-08-10 | 1996-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-08 | 1999-08-10 | 2000-02-09 | $7700.00 | Window Closed / Lapsed |