CA1112463A - Solid state analogue display with reduced connections - Google Patents
Solid state analogue display with reduced connectionsInfo
- Publication number
- CA1112463A CA1112463A CA302,903A CA302903A CA1112463A CA 1112463 A CA1112463 A CA 1112463A CA 302903 A CA302903 A CA 302903A CA 1112463 A CA1112463 A CA 1112463A
- Authority
- CA
- Canada
- Prior art keywords
- bar
- electrodes
- sector
- display
- segment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000007787 solid Substances 0.000 title 1
- 230000000875 corresponding effect Effects 0.000 claims 1
- 239000004973 liquid crystal related substance Substances 0.000 description 7
- UAGDSHSRQZJWSQ-HYJBFAGTSA-N Radiatin Chemical compound O[C@@H]1[C@@H](C)[C@@H]2C=CC(=O)[C@@]2(C)[C@@H](OC(=O)C(C)=C)[C@@H]2[C@H](C)C(=O)O[C@@H]21 UAGDSHSRQZJWSQ-HYJBFAGTSA-N 0.000 description 1
- UAGDSHSRQZJWSQ-UHFFFAOYSA-N Radiatin Natural products OC1C(C)C2C=CC(=O)C2(C)C(OC(=O)C(C)=C)C2C(C)C(=O)OC21 UAGDSHSRQZJWSQ-UHFFFAOYSA-N 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- JUFPAXGQNKVGNT-UHFFFAOYSA-N dihydrocliviasine Natural products CN1CCC2CC(O)C3OC(O)c4cc5OCOc5cc4C3C12 JUFPAXGQNKVGNT-UHFFFAOYSA-N 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000002674 ointment Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
- G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
- G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
- G09F9/35—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements being liquid crystals
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
-
- G—PHYSICS
- G04—HOROLOGY
- G04G—ELECTRONIC TIME-PIECES
- G04G9/00—Visual time or date indication means
- G04G9/02—Visual time or date indication means by selecting desired characters out of a number of characters or by selecting indicating elements the position of which represent the time, e.g. by using multiplexing techniques
- G04G9/06—Visual time or date indication means by selecting desired characters out of a number of characters or by selecting indicating elements the position of which represent the time, e.g. by using multiplexing techniques using light valves, e.g. liquid crystals
- G04G9/062—Visual time or date indication means by selecting desired characters out of a number of characters or by selecting indicating elements the position of which represent the time, e.g. by using multiplexing techniques using light valves, e.g. liquid crystals using multiplexing techniques
Landscapes
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Mathematical Physics (AREA)
- Theoretical Computer Science (AREA)
- Engineering & Computer Science (AREA)
- Optics & Photonics (AREA)
- Liquid Crystal Display Device Control (AREA)
- Liquid Crystal (AREA)
- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
- Electric Clocks (AREA)
- Indicating Measured Values (AREA)
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A display device for three variables such as hours, minutes, and seconds comprises an electro-optical display system with radical bar electrodes on one face and two segmental ring electrodes on the opposite face. Groups of bar electrodes form sectors of the display and cooperate with an inner segment and an outer segment for each sector and the bar electrodes of one sector are connected directly in reverse order to the bar electrodes of another sector.
An electronic drive circuit selects a bar electrode and one or both of the associated segment electrodes and is constructed to change the order of selection of the bars in accordance with the sector selected, thereby compensating for the reverse order of the connections.
A display device for three variables such as hours, minutes, and seconds comprises an electro-optical display system with radical bar electrodes on one face and two segmental ring electrodes on the opposite face. Groups of bar electrodes form sectors of the display and cooperate with an inner segment and an outer segment for each sector and the bar electrodes of one sector are connected directly in reverse order to the bar electrodes of another sector.
An electronic drive circuit selects a bar electrode and one or both of the associated segment electrodes and is constructed to change the order of selection of the bars in accordance with the sector selected, thereby compensating for the reverse order of the connections.
Description
The pre~ent invention relate~ to an analo~ue display device compri~ing an electro-opticQl sy~tel~ such as a liquid cry3tal sy-~te~ and nn electronic drive circuit for energi~ing clectrodeq disposed on opposite face~ of the electro-optical system and relates particularly to a display device suitable for the si~ultalleous display of three variables.
A display device of this character i~ described in my British Patent Specification No. l,472,2Go, which concerns A time-piece in which the display deYice ~imulates the hour and minute hands of a conventional watch or clock and also provides an analogue display of ~econdA. Reference 0 i6 made to Specif~cation No. 1,~72,260 for a description of the type~ o~
electro-optic~l sy~te~ which can be used and the ways in which individual rndial bars selected by the electronic c~rcuit can be made vi-~ible relative to other parts of the di~play to indicate by their an~ular position the hours~ minutes an~ 6econds.
Tt ha# now been appreciated that a display device as de~cribed in Specification No~ 1,4?2,260 can also be applied to the display of other ets of three variables instead of the hoursr minutes and seconds req~ired to be shown by a time piece. For example the variables displayed on an ~ircraft instrument m~ht be the nominal heading, the wind direction~ and the actual headinJ or for a motor vehicle instrurnent could be speed~
1emperature~ and fuel level. Thus the present invention is concerned roadly with a display de~ice for the dis~lay of three variables compri3in~
~ electro-optical syste~ having on one face a plurality of bar electrodeg radiatin~ fro~ a centra} point and on the other face two concentric ele~trode~ the electrodes bein3 connected to an e~ectronic drive circuit constructed to select a ~ar electrode w~t~ the inner of the concentric electrode~ for di~nlay of the first ~ariable~ a bar electrode with the
A display device of this character i~ described in my British Patent Specification No. l,472,2Go, which concerns A time-piece in which the display deYice ~imulates the hour and minute hands of a conventional watch or clock and also provides an analogue display of ~econdA. Reference 0 i6 made to Specif~cation No. 1,~72,260 for a description of the type~ o~
electro-optic~l sy~te~ which can be used and the ways in which individual rndial bars selected by the electronic c~rcuit can be made vi-~ible relative to other parts of the di~play to indicate by their an~ular position the hours~ minutes an~ 6econds.
Tt ha# now been appreciated that a display device as de~cribed in Specification No~ 1,4?2,260 can also be applied to the display of other ets of three variables instead of the hoursr minutes and seconds req~ired to be shown by a time piece. For example the variables displayed on an ~ircraft instrument m~ht be the nominal heading, the wind direction~ and the actual headinJ or for a motor vehicle instrurnent could be speed~
1emperature~ and fuel level. Thus the present invention is concerned roadly with a display de~ice for the dis~lay of three variables compri3in~
~ electro-optical syste~ having on one face a plurality of bar electrodeg radiatin~ fro~ a centra} point and on the other face two concentric ele~trode~ the electrodes bein3 connected to an e~ectronic drive circuit constructed to select a ~ar electrode w~t~ the inner of the concentric electrode~ for di~nlay of the first ~ariable~ a bar electrode with the
-2-outer o the concentric elcctrodes for di4play of the second ~ariable, and a bar electrode with both of the concentric electrodeg for display of the third variable~ the maQnitudes of the variables being ~hown by the angular position of the ~elected ~ar electrodes. Such a display device will be called hereafter a display de~ice Or the type defined.
In a display de~ice of the type defined, especially if it is to be made of small oYerall dimensions, for example a~ a wri~t watch~ it is important to reduce as far as po~sible the number of connections between the electronic drive circuit and the electro-optical 4ystem both because the ~0 a~ailable srace is limited and because the making of such connections adds significantly to the cost of manufacture. The ti~e-piece described in Specification No. 1~472,260 repre4ented a considerable advance in this direction becau~e a complete display of hour~ minutes, and seconds could be achieved with only sixty connections to the bar electrodes and two connection~ to the concentric electrode~. A further reduction would however be desirable if it could be achieved without degrading the quality of the diSplayt It i8 true that in British Patent Specification No. 1~46~976 there ; i~ described an electronic time-piece with a liquid crystal display device in which the number of connections between the display de~ice and the electronic circuit i~ reduced to twenty-four. ~his i-~ achieved by dividing ~ixty electrode~ into twe}ve blocks af five and connecting together the corresponding electrodes of the twelve blocks so that only five connections are nece~ary to the electronic circuit~ whsle a further twelve connection~
are made to twelve electrode ~e~ments on the oppo~ite face o the displ~y devicc each of which is common to the five electrode~ of one blo~c. Twe~e electrodec ~or the hour display are simil~rly di~i~ed into four hlocl;s of .
.
three~ requiring A further ~even connections. ~hi-~ howeYer doeJ not provide for ~y seconds display and moreoYer the minutes display i~
cumulative, that is to say as succes~ive electrode~ are turned on those previously turned on remain on. Apart fro~ the difficulty of reading such a display, which is quite different rrom the hands of a conventional watch, it incre~ses the time for which the liquid crystal system i9 energized and thereby reduce-~ it~ overall life-time.
In accordance with the present invention there is provided a di~play device of the type defined wherein the concentric electrodes are divided into segments ~uch that groups of bar electrode~ forming sectors of the display cooperate respectively with an inner se~ment and an outer segment for each sector and wherein the bar electrodes of one sector are connected directly in reverse order to the bar electrodes o* another sector~
the electronic circuit being constructed to select a seyment or se~ments in the required sector and to change the order of selection of the bars in accordance with the sector selected.
Thus the connections between the bar electrodes follow a similar pattern to that deJcri~ed in Specification No. 1~464~976. I~e reversal of the order Or the electrodes occurs because the connection~ are to be 2Q made on a flat surface and crossing over of the connector~ has therefore to be avoided. ~oweYer the use of the electronic circuit to compensate for this reversal makes it possible to ~elect any required bar electrode in con~unction with one or both of the associated segments to achieve a co~plete hours~ ~inute~ ~nd ~econds display while using, for e~a~ple, only 22 connections if there are f~ve group of twelve bar e~ectrodes or six groups of ten bsr electrodes~ with in the first case ten segment connections - and twelve bc~r connect~on~ or in the ~econd case twelve segment connections and ten bar electrod~ connection~.
~
In accordance with a particular embodiment of the invention, a display device for the display of three variables comprises an electro-optical system having on one face a plurality of bar electrodes radiating from a central point and on the other face two concentric electrodes, the elect-rodes being connected to an electronic drive circuit con-: structed to select a bar electrode with the inner of the con-centric electrodes for display of the first variable, a bar electrode with the outer of the concentric electrodes for display of the second variable, and a bar electrode with both of the concentric electrodes for display of the third variable, the magnitudes of the variables being shown by the angular position of the selected bar electrodes, wherein the concentric electrodes are divided into segments such that groups of bar electrodes forming sectors of the dis-play cooperate re~pectively with an inner segment and an outer segment for each sector and wherein the bar electrodes : of one sector are connected directly in reverse order to the bar electrodes of another sector, and wherein the electronic circuit comprises a bar selection and drive circuit for energizing any selected electrode of each of the groups, a segment drive circuit for energizing the inner segment, the ; outer segment, or both segments in any selected sector, a sector selector arranged to connect the segment drive cir-cuit to the selected sector, the sector selector also being connected to the bar selection and drive circuit by way of an inverter to reverse the outputs to the bar electrodes on switching from one sector to an adjacent sector.
- 4a -~he ~n~etltion will now be de~cribed in ~ore detail with the ~id of an ex~2p-e illuqtrated in the acco~npanying drawing~ in which ~-Fi~2. 1 iq a block circuit diagrant of a display device in accorda~tce with the invention intended primarily for u~e as a time-piec~ but showing also the modifications necesqary for display of three independent measured ~ar$ables, Fi~. 2 i~ a dia~2rarn of the layout and connection~ of the electrodes of the electro-optical syste~ for the display device of Fi~ and Fi~s. 3 and 4 ~how the actual pattern o* electrode~ and connections on the two face~ of the electro-optical sy~tem when thi~ i~ a liquid crystal 2y~te2n.
Tbe circuit Rhown in ~ s si~ilar in many respects to the circuit ~hown in Fi~2. 3 of Specification No. 1,472,260 end for ease of reference the s~ne reference nunterals have been used for the corresponding elementq in the two Fi~ures. ~he circuit is controlled by a time base in the form of a ory~tal oscillator 21. Pulses from the oscillator 21 pass to a 16-~ta~e di~ider 22 which delirers one pul~te per second to a second-~
counter 23. The second~ counter in turn deliver~ one pul#e per minute to a minutes counter 2~, which deliver~ twelve pul~es per hour to an hour~
c~unter 25. The outputq of the counters 23~ 24 and 25 are fed in binary coded decimal form to a multiplexer consisting of switching units 26, 27, 23 and 29 which recei~e pair~ of input~ fro~ the counters as shown. The switching unit~ 26 to 29 are controlled by a data display selection circuit 30 which receive~ pulqes fro~tt the divider 22 at the multipl~x frequel~cy ~td ~5 by meaut~ of a divide-~y-3 divider delirer~ in turn a "second~" output on l~ne ~1~ a~minuteq" output on lines 31 and 32, and an ~hours~ out~ut on line 32. rhe~e outp~ts are also deiirered to a se~2n2ent drire circuit 33 which control~ the ener~iz~tion of the appropriata electrode segment in a liquid crystal displ~y syste~ 34.
The outputs of the switching units 28 and 29 are passed to decoding units ~0 and 41 which convert the signals from binary coded decimal to one o~ si~ty, the unit 40 havin~ outputs 0 to 9 and the unit 41 having outputs 00~ 10~ 20, 30~ 40~ and 50. The output of`the decoding unit 41 is passed to the ~eg.~ent drive circuit 33 to select the appro-priate sector of the display ~ ~ al~o control4 an inverter 42 which reverse~ the order of the outputs of the decoding unit 40 each time the next sector of the display i~ selected. These outputs from the unit 40 by ~ay of a bar driver circuit 43, control the energization of the ten bar electrode~ in the selected ~ector. An A.C. ~quare wave generator 39 driven at multiplex frequency by signal-~ from the diviAer 22 provides the ~lternating field required between opposite electrodes of the liquid crystal d~splay syste.n 34.
The multiplex frequency from the divider 22~ which may for example be 40 ~z. is applied to the ~election circuit 30 which swit~hes the mult~plexer between the seconds, minute~ and hours counters 23~ 24 and 25 and at the same time~ in the se~ment drive 33~ selects the appropriate segmen*s tor display of seconds, minutes, and hours. As time advances the seconds counter 23 steps on and the output from unit 40 causes the bar electrodes in one ~ector to be selected in turn~ after which the output from unit 41 chan~es to select the next ~ector, by switching to the next set of connection~ between the segment drive 33 and the electrode ~e~ments of the display system 34. At the same time the invarter ~2 i9 operated ~o reverse tha sequence of the output~ ~rom unit ~0 so that the b~r electrode~ in tlle next ~ector are selected in reverse orAer~ thus 6~
con~pon~at~n~ for thc phy~ical re~crsal of the electrodes resulting from the mA~Ier of their connection~ which will now be de3cribed.
The layout diagra~ of Fi8. 2 ~hows a diQplay ~ystem divided into 8iX sectors defined by inncr electrode se~ents 44A to 44F and outer electrode se~ments 45A to 45F. In each sector th re are ten bar electrode~ labelled AO to A9~ BO to B9, and ~o on. It will be understood that the inner and outer electrod~ segments are on one face of a liquid crystal device while the bar electrodes are on the opposite face. The bar electrodeq of ~ector A are connected at their outer ends to re-~pective terminals ID to T9 and at their inner ends to respective bar electrode~
of sector B. Howe~er, to avoid any cro~-o~er of the connectors it will be seen that the bar electrodes of sector B are connected in the reverqe order, that i~ B9 to 40~ B8 to Al~ and ~o on with BO connected to A9. The connections are made at the outer ends of the bar electrodes between those f ~ector B and those of sector C, the order again being reversed. However it will be seen that B9 and ~0 ~re directly connected at their inner ends.
This form of S connection, alternately at the inner and outer ends, is continued throu~hout the six ~ector~ so that~ for example, t~:e terminal T3 i~ connected in ~eries with bar electrodes A3, B6~ C3, D6, E3, and F6.
ao In addition to the ter~inal~ ~0 to T9, terminals Sl to Sl2 are provided, which are connected to tile electrode se~men*s ~4A to 44F and ~5A to 45F as ~hown. There are thu~ a total of lO bar terminalQ and 12 se~ment terminal_ to which connections must ~e made fro~ the electronic circuit of Fi~. l.
Tuelve se~ment electrodes with their associated col-nection lead~
are shown sn printed circuit form in Fig. 3. Whereas in ~ig. ~ thc termlnal3 Rs~e all arranged alon~ one ed~e of the display, Figs. 3 and 4 oho~ an arran~ement with terminals along two opposite edye- and in which correspondin~ bAr electrode-~ ure not connected in series through-out all the sectors but are simply grouped in pairs with central connections. 2hus in Fiy. 4 there are ten bar electrode terminals TO to T9 connected to the bar electrodes AO to A9 but it will be noted that the connection of TO to AO i9 in fact by way of electrode F9 while the conne~tion of T9 is throu~h electrode BO. The bar electrodes AO to A9 are connected respectively with electrodes B9 to BO. Similarly CO to C9 are connected respectively with D9 to DO and EO to E9 with F9 to FO. Additionally~
there i9 a central connection bet~een AO~ B9~ CO~ D9~ &0~ and F9. Additional terminals LO to L8 are connected directly to bar electrode~ FO to Fôt respectively~ and similarl~ at the opposite edge o~ the array there are terminals MO to M9 connected re~pectively to bar electrodes CO to C9 and terminals Nl to N9 connected re~pectively to electrodeJ Dl to D8 and EO.
By external connections between selected terminals it i~ then possible to ensure that the same ~ignal i~ applied to correspondin~ bar electrodes in all ~ix sectors. For example the terminals Tl~ L8 and Ml and/or N8 are connected to a common point so that electrodes Al~ B8~ Cl~ D~ El, and F8 receive the same signal.
Fiy. 4 additional?y ~hows terminals Sl to S12 for connection to the seyment electrodes 44E~ 45F~ 44F~ 45A~ 44~ 45B~ 44B~ 45C~ 44C~ 45D~
44D, and 45E respectively. These terminals are placed for convenience on the same board a~ tbe other ter~inals and connections are made from them across the liquid crystal unit to the cond~ctors on the board which carries the se~ment electrodes.
:`
-8_
In a display de~ice of the type defined, especially if it is to be made of small oYerall dimensions, for example a~ a wri~t watch~ it is important to reduce as far as po~sible the number of connections between the electronic drive circuit and the electro-optical 4ystem both because the ~0 a~ailable srace is limited and because the making of such connections adds significantly to the cost of manufacture. The ti~e-piece described in Specification No. 1~472,260 repre4ented a considerable advance in this direction becau~e a complete display of hour~ minutes, and seconds could be achieved with only sixty connections to the bar electrodes and two connection~ to the concentric electrode~. A further reduction would however be desirable if it could be achieved without degrading the quality of the diSplayt It i8 true that in British Patent Specification No. 1~46~976 there ; i~ described an electronic time-piece with a liquid crystal display device in which the number of connections between the display de~ice and the electronic circuit i~ reduced to twenty-four. ~his i-~ achieved by dividing ~ixty electrode~ into twe}ve blocks af five and connecting together the corresponding electrodes of the twelve blocks so that only five connections are nece~ary to the electronic circuit~ whsle a further twelve connection~
are made to twelve electrode ~e~ments on the oppo~ite face o the displ~y devicc each of which is common to the five electrode~ of one blo~c. Twe~e electrodec ~or the hour display are simil~rly di~i~ed into four hlocl;s of .
.
three~ requiring A further ~even connections. ~hi-~ howeYer doeJ not provide for ~y seconds display and moreoYer the minutes display i~
cumulative, that is to say as succes~ive electrode~ are turned on those previously turned on remain on. Apart fro~ the difficulty of reading such a display, which is quite different rrom the hands of a conventional watch, it incre~ses the time for which the liquid crystal system i9 energized and thereby reduce-~ it~ overall life-time.
In accordance with the present invention there is provided a di~play device of the type defined wherein the concentric electrodes are divided into segments ~uch that groups of bar electrode~ forming sectors of the display cooperate respectively with an inner se~ment and an outer segment for each sector and wherein the bar electrodes of one sector are connected directly in reverse order to the bar electrodes o* another sector~
the electronic circuit being constructed to select a seyment or se~ments in the required sector and to change the order of selection of the bars in accordance with the sector selected.
Thus the connections between the bar electrodes follow a similar pattern to that deJcri~ed in Specification No. 1~464~976. I~e reversal of the order Or the electrodes occurs because the connection~ are to be 2Q made on a flat surface and crossing over of the connector~ has therefore to be avoided. ~oweYer the use of the electronic circuit to compensate for this reversal makes it possible to ~elect any required bar electrode in con~unction with one or both of the associated segments to achieve a co~plete hours~ ~inute~ ~nd ~econds display while using, for e~a~ple, only 22 connections if there are f~ve group of twelve bar e~ectrodes or six groups of ten bsr electrodes~ with in the first case ten segment connections - and twelve bc~r connect~on~ or in the ~econd case twelve segment connections and ten bar electrod~ connection~.
~
In accordance with a particular embodiment of the invention, a display device for the display of three variables comprises an electro-optical system having on one face a plurality of bar electrodes radiating from a central point and on the other face two concentric electrodes, the elect-rodes being connected to an electronic drive circuit con-: structed to select a bar electrode with the inner of the con-centric electrodes for display of the first variable, a bar electrode with the outer of the concentric electrodes for display of the second variable, and a bar electrode with both of the concentric electrodes for display of the third variable, the magnitudes of the variables being shown by the angular position of the selected bar electrodes, wherein the concentric electrodes are divided into segments such that groups of bar electrodes forming sectors of the dis-play cooperate re~pectively with an inner segment and an outer segment for each sector and wherein the bar electrodes : of one sector are connected directly in reverse order to the bar electrodes of another sector, and wherein the electronic circuit comprises a bar selection and drive circuit for energizing any selected electrode of each of the groups, a segment drive circuit for energizing the inner segment, the ; outer segment, or both segments in any selected sector, a sector selector arranged to connect the segment drive cir-cuit to the selected sector, the sector selector also being connected to the bar selection and drive circuit by way of an inverter to reverse the outputs to the bar electrodes on switching from one sector to an adjacent sector.
- 4a -~he ~n~etltion will now be de~cribed in ~ore detail with the ~id of an ex~2p-e illuqtrated in the acco~npanying drawing~ in which ~-Fi~2. 1 iq a block circuit diagrant of a display device in accorda~tce with the invention intended primarily for u~e as a time-piec~ but showing also the modifications necesqary for display of three independent measured ~ar$ables, Fi~. 2 i~ a dia~2rarn of the layout and connection~ of the electrodes of the electro-optical syste~ for the display device of Fi~ and Fi~s. 3 and 4 ~how the actual pattern o* electrode~ and connections on the two face~ of the electro-optical sy~tem when thi~ i~ a liquid crystal 2y~te2n.
Tbe circuit Rhown in ~ s si~ilar in many respects to the circuit ~hown in Fi~2. 3 of Specification No. 1,472,260 end for ease of reference the s~ne reference nunterals have been used for the corresponding elementq in the two Fi~ures. ~he circuit is controlled by a time base in the form of a ory~tal oscillator 21. Pulses from the oscillator 21 pass to a 16-~ta~e di~ider 22 which delirers one pul~te per second to a second-~
counter 23. The second~ counter in turn deliver~ one pul#e per minute to a minutes counter 2~, which deliver~ twelve pul~es per hour to an hour~
c~unter 25. The outputq of the counters 23~ 24 and 25 are fed in binary coded decimal form to a multiplexer consisting of switching units 26, 27, 23 and 29 which recei~e pair~ of input~ fro~ the counters as shown. The switching unit~ 26 to 29 are controlled by a data display selection circuit 30 which receive~ pulqes fro~tt the divider 22 at the multipl~x frequel~cy ~td ~5 by meaut~ of a divide-~y-3 divider delirer~ in turn a "second~" output on l~ne ~1~ a~minuteq" output on lines 31 and 32, and an ~hours~ out~ut on line 32. rhe~e outp~ts are also deiirered to a se~2n2ent drire circuit 33 which control~ the ener~iz~tion of the appropriata electrode segment in a liquid crystal displ~y syste~ 34.
The outputs of the switching units 28 and 29 are passed to decoding units ~0 and 41 which convert the signals from binary coded decimal to one o~ si~ty, the unit 40 havin~ outputs 0 to 9 and the unit 41 having outputs 00~ 10~ 20, 30~ 40~ and 50. The output of`the decoding unit 41 is passed to the ~eg.~ent drive circuit 33 to select the appro-priate sector of the display ~ ~ al~o control4 an inverter 42 which reverse~ the order of the outputs of the decoding unit 40 each time the next sector of the display i~ selected. These outputs from the unit 40 by ~ay of a bar driver circuit 43, control the energization of the ten bar electrode~ in the selected ~ector. An A.C. ~quare wave generator 39 driven at multiplex frequency by signal-~ from the diviAer 22 provides the ~lternating field required between opposite electrodes of the liquid crystal d~splay syste.n 34.
The multiplex frequency from the divider 22~ which may for example be 40 ~z. is applied to the ~election circuit 30 which swit~hes the mult~plexer between the seconds, minute~ and hours counters 23~ 24 and 25 and at the same time~ in the se~ment drive 33~ selects the appropriate segmen*s tor display of seconds, minutes, and hours. As time advances the seconds counter 23 steps on and the output from unit 40 causes the bar electrodes in one ~ector to be selected in turn~ after which the output from unit 41 chan~es to select the next ~ector, by switching to the next set of connection~ between the segment drive 33 and the electrode ~e~ments of the display system 34. At the same time the invarter ~2 i9 operated ~o reverse tha sequence of the output~ ~rom unit ~0 so that the b~r electrode~ in tlle next ~ector are selected in reverse orAer~ thus 6~
con~pon~at~n~ for thc phy~ical re~crsal of the electrodes resulting from the mA~Ier of their connection~ which will now be de3cribed.
The layout diagra~ of Fi8. 2 ~hows a diQplay ~ystem divided into 8iX sectors defined by inncr electrode se~ents 44A to 44F and outer electrode se~ments 45A to 45F. In each sector th re are ten bar electrode~ labelled AO to A9~ BO to B9, and ~o on. It will be understood that the inner and outer electrod~ segments are on one face of a liquid crystal device while the bar electrodes are on the opposite face. The bar electrodeq of ~ector A are connected at their outer ends to re-~pective terminals ID to T9 and at their inner ends to respective bar electrode~
of sector B. Howe~er, to avoid any cro~-o~er of the connectors it will be seen that the bar electrodes of sector B are connected in the reverqe order, that i~ B9 to 40~ B8 to Al~ and ~o on with BO connected to A9. The connections are made at the outer ends of the bar electrodes between those f ~ector B and those of sector C, the order again being reversed. However it will be seen that B9 and ~0 ~re directly connected at their inner ends.
This form of S connection, alternately at the inner and outer ends, is continued throu~hout the six ~ector~ so that~ for example, t~:e terminal T3 i~ connected in ~eries with bar electrodes A3, B6~ C3, D6, E3, and F6.
ao In addition to the ter~inal~ ~0 to T9, terminals Sl to Sl2 are provided, which are connected to tile electrode se~men*s ~4A to 44F and ~5A to 45F as ~hown. There are thu~ a total of lO bar terminalQ and 12 se~ment terminal_ to which connections must ~e made fro~ the electronic circuit of Fi~. l.
Tuelve se~ment electrodes with their associated col-nection lead~
are shown sn printed circuit form in Fig. 3. Whereas in ~ig. ~ thc termlnal3 Rs~e all arranged alon~ one ed~e of the display, Figs. 3 and 4 oho~ an arran~ement with terminals along two opposite edye- and in which correspondin~ bAr electrode-~ ure not connected in series through-out all the sectors but are simply grouped in pairs with central connections. 2hus in Fiy. 4 there are ten bar electrode terminals TO to T9 connected to the bar electrodes AO to A9 but it will be noted that the connection of TO to AO i9 in fact by way of electrode F9 while the conne~tion of T9 is throu~h electrode BO. The bar electrodes AO to A9 are connected respectively with electrodes B9 to BO. Similarly CO to C9 are connected respectively with D9 to DO and EO to E9 with F9 to FO. Additionally~
there i9 a central connection bet~een AO~ B9~ CO~ D9~ &0~ and F9. Additional terminals LO to L8 are connected directly to bar electrode~ FO to Fôt respectively~ and similarl~ at the opposite edge o~ the array there are terminals MO to M9 connected re~pectively to bar electrodes CO to C9 and terminals Nl to N9 connected re~pectively to electrodeJ Dl to D8 and EO.
By external connections between selected terminals it i~ then possible to ensure that the same ~ignal i~ applied to correspondin~ bar electrodes in all ~ix sectors. For example the terminals Tl~ L8 and Ml and/or N8 are connected to a common point so that electrodes Al~ B8~ Cl~ D~ El, and F8 receive the same signal.
Fiy. 4 additional?y ~hows terminals Sl to S12 for connection to the seyment electrodes 44E~ 45F~ 44F~ 45A~ 44~ 45B~ 44B~ 45C~ 44C~ 45D~
44D, and 45E respectively. These terminals are placed for convenience on the same board a~ tbe other ter~inals and connections are made from them across the liquid crystal unit to the cond~ctors on the board which carries the se~ment electrodes.
:`
-8_
Claims (5)
1. A display device for the display of three variables comprising an electo-optical system having on one face a plurality of bar electrodes radiating from a central point and on the other face two concentric electrodes, the elect-rodes being connected to an electronic drive circuit con-structed to select a bar electrode with the inner of the con-centric electrodes for display of the first variable, a bar electrode with the outer of the concentric electrodes for display of the second variable, and a bar electrode with both of the concentric electrodes for display of the third variable, the magnitudes of the variables being shown by the angular position of the selected bar electrodes, wherein the concentric electrodes are divided into segments such that groups of bar electrodes forming sectors of the display cooperative respectively with an inner segment and an outer segment for each sector and wherein the bar elect-rodes of one sector are connected directly in reverse order to the bar electrodes of another sector, and wherein the electronic circuit comprises a bar selection and drive circuit for energizing any selected electrode of each of the groups, a segment drive circuit for energizing the inner segment, the outer segment, or both segments in any selected sector, a sector selector arranged to connect the segment drive circuit to the selected sector, the sector selector also being connected to the bar selection and drive circuit by way of an inverter to reverse the outputs to the bar electrodes on switching from one sector to an adjacent sector.
2. A display device as claimed in claim 1 wherein connections between successive sectors are made alternately at the inner ends of the bar electrodes and at the outer ends of the bar electrodes throughout all the sectors.
3. A display device as claimed in claim 2 in which the bar electrodes and their interconnections are in printed circuit form.
4. A display device as claimed in claim 1 for display of hours, seconds, and minutes as the first, second, and third variables wherein there are six groups of ten bar electrodes and six segments in each of the concentric electrodes.
5. A display device as claimed in claim 1 including a data display selection circuit whose output is connected to the segment drive circuit and also to a multiplexer for applying stored signals representing the values of the three variables to the bar selection and drive circuit and the sector selector, the data display selection circuit switching rapidly and repeatedly between inner segment, outer segment, and both segments and at the same time selecting the corres-ponding variable by means of the multiplexer.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB19887/77A GB1599667A (en) | 1977-05-12 | 1977-05-12 | Electrooptical analogue display with reduced connections |
| GB19887/77 | 1977-05-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1112463A true CA1112463A (en) | 1981-11-17 |
Family
ID=10136827
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA302,903A Expired CA1112463A (en) | 1977-05-12 | 1978-05-09 | Solid state analogue display with reduced connections |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS53140997A (en) |
| CA (1) | CA1112463A (en) |
| DE (1) | DE2820326A1 (en) |
| FR (1) | FR2390793A2 (en) |
| GB (1) | GB1599667A (en) |
| IT (1) | IT1113178B (en) |
| NL (1) | NL7805194A (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2803899C2 (en) * | 1978-01-30 | 1983-05-26 | Hans Uwe Dipl.-Phys. 8021 Taufkirchen Reif | Method for controlling a quasi-analog clock display device |
| DE2834387C3 (en) | 1978-08-05 | 1981-04-16 | Eurosil GmbH, 8000 München | Electro-optical time display device |
| JPS55114986A (en) * | 1979-02-27 | 1980-09-04 | Seikosha Co Ltd | Needle display unit |
| JPS55155212A (en) * | 1979-05-23 | 1980-12-03 | Seiko Epson Corp | Multichannel display |
| JPS55163487A (en) * | 1979-06-07 | 1980-12-19 | Seikosha Co Ltd | Displaying device |
| JPS55164395A (en) * | 1979-06-11 | 1980-12-22 | Seikosha Co Ltd | Timer |
| JPS56154694A (en) * | 1980-04-30 | 1981-11-30 | Pioneer Electronic Corp | Electronic analog display timepiece |
| GB2144255B (en) * | 1983-07-28 | 1987-01-14 | Secr Defence | A meter display |
| JPS6247578A (en) * | 1985-08-27 | 1987-03-02 | Rhythm Watch Co Ltd | Analog display timepiece |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3540209A (en) * | 1968-07-31 | 1970-11-17 | Timex Corp | Horological time display |
-
1977
- 1977-05-12 GB GB19887/77A patent/GB1599667A/en not_active Expired
-
1978
- 1978-05-09 CA CA302,903A patent/CA1112463A/en not_active Expired
- 1978-05-10 FR FR7813871A patent/FR2390793A2/en active Granted
- 1978-05-10 DE DE19782820326 patent/DE2820326A1/en not_active Ceased
- 1978-05-11 JP JP5610278A patent/JPS53140997A/en active Pending
- 1978-05-12 IT IT23353/78A patent/IT1113178B/en active
- 1978-05-12 NL NL7805194A patent/NL7805194A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| FR2390793B2 (en) | 1984-12-28 |
| IT7823353A0 (en) | 1978-05-12 |
| DE2820326A1 (en) | 1978-11-23 |
| IT1113178B (en) | 1986-01-20 |
| FR2390793A2 (en) | 1978-12-08 |
| JPS53140997A (en) | 1978-12-08 |
| NL7805194A (en) | 1978-11-14 |
| GB1599667A (en) | 1981-10-07 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |