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Publication numberUS3886726 A
Publication typeGrant
Publication dateJun 3, 1975
Filing dateJun 19, 1972
Priority dateJun 19, 1972
Also published asCA975063A1, CA990349A1, CA999356A1, CA1006588A1, CA1006914A1, CA1010971A1, CA1011431A1, CA1013030A1, DE2326899A1, US3783308, US3809994, US3828548, US3838564, US3893017, US4080780
Publication numberUS 3886726 A, US 3886726A, US-A-3886726, US3886726 A, US3886726A
InventorsClark R Williams, Robert H Schnurr
Original AssigneeTexas Instruments Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Electronic time keeping system
US 3886726 A
Abstract
An electronic timekeeping device includes bipolar integrated circuit implemented logic in combination with a liquid crystal display. The bipolar circuitry is configured to effectively implement logic functions with a supply voltage of only one volt. Drive circuitry is coupled to the liquid crystal display to effectively impress an a.c. voltage across the liquid crystal cell when display is required. The logic circuitry includes a transistor configured current source regulated to effectively maintain a current independent of source and load variations, enabling integrated circuit implementation without utilizing large value external resistors. The display circuitry includes logic for enabling display of the calendar date and time, reset capabilities independent of date increments are provided.
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Claims  available in
Description  (OCR text may contain errors)

United States Patent 11 1 ,n 11 3,886,726 Williams et al. 1 June 3, 1975 [54] ELECTRONIC TIME KEEPING SYSTEM 3.750383 8/1973 Kakizawa 58/233 A [73] Assignee: Texas Instruments incorporated, C J S h S, s dacca Dallas, Tex.

[22] Filed: June 19, 1972 {57] ABSTRACT [2]] Appl 2 4 212 An electronic timekeeping device includes bipolar integrated circuit implemented logic in combination with a liquid crystal display. The bipolar circuitry is Cl 58/50 R; 58/4 58/23 configured to effectively implement logic functions 58/58; 58/85'5 with a supply voltage of only one volt. Drive circuitry f G04b 19/30; G041" 11/24; G04) is coupled to the liquid crystal display to effectively of Search 58/23 50 impress an ac. voltage across the liquid crystal cell 350M) LC when display is required. The logic circuitry includes a transistor configured current source regulated to ef- Retemnces Cited fectively maintain a current independent of source UNITED STATES PAT TS and load variations, enabling integrated circuit imple- 3,072,155 6/1972 Bergey et a1 58/50 R mentation without utilizing large value external resis- 3,596,462 8/1971 Hayes 58/127 R tors. The display circuitry includes logic for enabling 3. 0 6/1972 Dierbock 4 58/23 BA display of the calendar date and time, reset capabili- 3.69l,755 9/l972 Gifard a a e 53/50 R ties independent of date increments are provided. 3,699,703 10/1972 Zeph 53/23 R 3,733,810 3/1971 Girard 58/50 R 6 Claims, 47 Drawing Figures SUPPLY CURRENT REGULATOR FIG. 25 /6 id ssc. RESET use. FREQ" secures P RESET FIG-5 h 23 g FIGS noun RESET fi-mra RESET CLOCK SYSTEM U 22 DECODE FIGS. 6-,

U I? DRIJEF. nlspm r FIGS. 1-; 3 FIG. 3 14 2s SUPPLY CONVERTER Inventors: Clark R. Williams; Robert H.

Schnurr, both of Dallas, Tex.

Primary Examiner-Edith Simmons Jackmon Attorney, Agent, or Firml-larold Levine; Edward J.

PATENTEUJUHB ms 3.886726 SHEET 1 SUPPLY M 0 l 1.

cuimm REGULATOR FIG. 25 m DSESE'R COUNTER FIGS. 6- no.5 FIG. 6 s

CLOCK SYSTEM SEC. RESET MIN. RESET HOUR RESET DATE RESET DECODE FIGS. 6- ./-24

I? U DRIVER DISPLAY FIGS. 6-9 FIG. 3 l4 1 28 SUPPLY CONVERTER FIG. 32

alseslv'zs PATENTEUJUH SHEET w t oHwoQ am wm "BEE 0H m HDOMBOHQM Mo m wm media x5758 BEE NN V630 w zmewwm PATENTEDJUN 3 ms SHEET E55 82 58mm m wm @055 T 25 mmazpoo a T mKDOI PAIENTEBJum I575 3.886723 SHEET 8 l CLEAR CLOCK PRESET I CLOCK II|| |II|Il|llI| IIIIIIIIIIIIIIIIIII I l l I I I I I I l I I I I I I l l L I U M Fig. /0E

CLEAR PRESE'I' O O O O o PATENTEIJJUHB m5 3886726 sum 9 REF.

UNDETERMINED R CLEAR c|.oc| PRESET REF.

CLEAR CLOCK PRESET PATENTED UH I975 SHEEI MUOAO mm Ni NM PATENTEUJUEES ms 1886.726

saw 1 1 CLOCK ENAB LE ENA BLE 0 60 EN CR 2N C l NcR ENCR ENCR 0s Q --Cs6 -cs QC JUSQD {350E CLC CLCL CLCL. CL. CL.

CLEAR STATE DIAGRAM EMHHEBJU?! 3 I975 31386126 SHEET 1 2 FROM DIVIDE BY 10 COUNTER A AEBECDDEE PATENTEDJUH 3 I975 SHEET 1 3 LIQUID C RYSTA L INPUT -C INPUT LOGIC IN PU T PATENTEUJUM ms 3386726 SHEET 14 CLOCK ENA BLE C LEA TC IN-TC STA TE DIAGRAM Fig. /9 QA CLOCK ENABLE IN-TC PM'HHEDJ'J113 m5 1 5726 saw 15 FROM -1 24 COUNTER AZBECEDDE DISPLA Y SEGMENT Fig. 23

ATABEcCDEEE J Y TO I- 24 DECODER-DRIVERS PATENIEDJUII3 I975 SHEET 1| I MMBM HB Q I I. .I I. I II I I IJ in n OW m I 1. I I I I I I W2. B mnoumo m 0H m A m l I I I I II I I I I I l I I I I I I. I I I I I I I I... an zm kw zm zm zm zm zm mu v6 no no mo x0 no EHHwMm PMENTEDJULB ms 3.886726 SHEET 18 P+ ISOLA TION C3 C1 B :1

Fig. 280

Fig. 29

SUPPLY REFERENCE Fig, 30

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3072155 *Sep 14, 1959Jan 8, 1963Sulzer AgThread clamp for weaving machines
US3596462 *Jan 31, 1969Aug 3, 1971Hayes RoyceElectronic clock
US3668860 *Nov 5, 1970Jun 13, 1972Timex CorpHigh voltage watch power supply
US3691755 *Oct 16, 1970Sep 19, 1972Manuf Des Montres Rolex SaClock with digital display
US3699703 *May 20, 1970Oct 24, 1972Biecker Thomas CPuppet theater
US3733810 *Mar 5, 1971May 22, 1973Rolex MontresTimepiece with electronically designed digital read-out
US3750383 *Dec 27, 1971Aug 7, 1973Suwa Seikosha KkQuartz-oscillator controlled timepiece using liquid crystal display device
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3979899 *Apr 1, 1975Sep 14, 1976Mitsubishi Denki Kabushiki KaishaDigital display type electronic time keeper
US3994124 *May 1, 1975Nov 30, 1976Kabushiki Kaisha Suwa SeikoshaElectronic timepiece
US4020626 *May 14, 1975May 3, 1977Kabushiki Kaisha Daini SeikoshaElectronic timepiece
US4028879 *Jul 24, 1975Jun 14, 1977Eurosil G.M.B.H.Switching arrangement for setting time-measuring apparatus
US4104858 *Jul 6, 1976Aug 8, 1978Texas Instruments IncorporatedBipolar logic having graded power
US4112670 *Mar 4, 1976Sep 12, 1978Kabushiki Kaisha Suwa SeikoshaElectronic timepiece
US4150537 *Oct 18, 1977Apr 24, 1979Citizen Watch Company LimitedElectronic timepiece and method for testing operation of the same
Classifications
U.S. Classification368/84, 327/108, 368/87, 331/116.00R, 968/876, 968/503, 331/112, 968/878, 968/933, 968/965, 968/498, 968/888, 968/914
International ClassificationG04G99/00, G04C10/00, G04C9/00, G04G9/00, G04G17/02, G04G19/00, H01L27/00, H03K3/012, G04G9/12, G04G5/04, H03K3/289
Cooperative ClassificationH03K3/289, G04G5/04, G04G19/00, H03K3/012, G04G9/0047, H01L27/00, G04C10/00, G04G9/126, G04G17/02, G04G99/00, G04C9/00
European ClassificationH01L27/00, G04C10/00, G04G9/12D, G04G9/00D1C, H03K3/012, G04G19/00, G04G17/02, H03K3/289, G04C9/00, G04G5/04, G04G99/00