11||110l|||l1WilllWilllllWil
`WillllllllllWilllllWWilllWilllllWllll
`
`United States Patent
`Itaya et al.
`
`[19]
`
`[11] Patent Number:
`[45] Date of Patent:
`
`5,181,030
`Jan. 19, 1993
`
`[54]
`
`[75]
`
`INPUT SYSTEM INCLUDING RESISTANCE
`FILM TOUCH PANEL AND PUSHED
`POSITION DETECTINGDEVICE
`Inventors: Hisso Itaya, Moriyama; Kazuhiko
`Akebi, Kurita; Minoru Okabe;Satoru
`Nakagawa,both of Moriyama, all of
`Japan
`[73] Assignee:. Gunze Limited, Ayabe, Japan
`[21] Appl. No.: 614,410
`[22] Filed:
`Nov. 16, 1990
`[30]
`Foreign ApplicationPriority Data
`Dec. 28, 1989 [JP]
`1-340758
`Japan
`..................................
`Mar. 22, 1990 [JP]
`...............................2-30219{U]
`Japan
`[51]
`.............................................H03K 17/94
`Int. Cl.5
`[52] U.S. Cl.
`341/20; 178/18;
`........................................
`340/706
`[58] Field of Search
`341/20, 22, 24, 25,
`.......................
`341/26; 178/18, 19, 20; 340/706, 712; 338/99,
`114; 382/3, 4
`
`[56]
`
`ReferencesCited
`U.S. PATENT DOCUMENTS
`..................................178/l 8
`3,885,097 5/1975 Pobgee
`..................................I78/18
`4,149,029 4/1979 Pobgee
`4,571,454 2/1986 Tamaru et al.
`178/18
`.......................
`4,571,577 2/1986 Taupin et al. .........................
`178/18
`
`4,636,582 1/1987 Moriwaki et al. .................... 178/18
`Primary Examiner-Donald1.Yusko
`Assistant Examiner-Robert Gray
`Attorney, Agent, or Firm-Armstrong & Kubovcïk
`[57]
`ABSTRACT
`An input system including a resistancefilm touch panel
`and a pushed position detecting device for detecting
`two-dimensional coordinates of a pushed position of a
`touch panel based on surface resistancevalues of resis-
`tance films, the system comprising a pair of insulating
`base layers opposed to each other with a certain dis-
`tance therebetween; a spacer provided between the
`insulating base layers for keeping the layers apart but
`for allowing the layers to approach each other when an
`external force is applied to one of the layers; a first
`resistance film extended in first and second directions
`and provided on an inner surface of one of the layers,
`the first and second directions crossing each other per-
`pendicularly.and the first resistance film having outer
`connecting electrodes on both ends thereof along the
`second direction; and a plurality of second resistance
`films provided on an inner surface of the other of the
`layers, the second resistancefilms each being a lengthy
`strip extended in a direction crossing the second direc-
`tion and having first and second outer connecting elec-
`trodes at both ends thereof.
`
`9 Claims, 12 Drawing Sheets
`
`+V2
`
`I; 3 e 5
`
`l-. 7
`
`42
`)
`
`43
`
`44
`
`18 -+ OUT-- CONTROLLER
`
`- DECODER -
`
`45
`
`102
`
`6
`
`4
`
`7
`
`5
`
`SCEA Ex. 1028 Page 1
`
`

`
`U.S. Patent
`
`Jan. 19, 1993
`
`Sheet 1 of 12
`
`5,181,030
`
`Fig. 1
`
`PRIOR ART
`
`95
`
`r'
`
`r3
`
`---^Wv- B
`
`93-
`
`Y axis
`
`X axis
`
`V1
`
`96
`
`92
`
`91
`
`94
`
`Fig. 2
`
`PRIOR ART
`
`102
`
`-J nonnnn h
`
`101
`
`Y axis
`
`X axis
`
`SCEA Ex. 1028 Page 2
`
`

`
`U.S. Patent
`
`Jan. 19, 1993
`
`Sheet 2 of 12
`
`5,181,030
`
`Fi g.3
`
`r 4
`
`3
`
`4
`
`6
`
`-11
`
`L X AXIS L4
`
`Fig.4
`
`c=
`
`10
`
`Fig.5a
`
`4
`
`4
`
`5
`
`4
`
`9
`
`Fig.5b
`
`SCEA Ex. 1028 Page 3
`
`

`
`U.S. Patent
`
`Jan. 19, 1993
`
`Sheet 3 of 12
`
`5,181,030
`
`LaJ
`
`O
`
`O
`
`O
`
`N
`
`o
`
`?
`
`o
`
`C
`
`o
`
`-
`
`o
`
`D
`
`o
`
`C
`
`SCEA Ex. 1028 Page 4
`
`

`
`U.S. Patent
`
`Jan. 19, 1993
`
`Sheet 4 of 12
`
`5,181,030
`
`V2 d..____..-li
`
`3
`
`C
`
`------ VS
`
`DISTANCE
`
`Fig.7a
`
`II
`
`7
`
`10
`
`a V2 / 6
`VI c D
`
`Oa-
`
`E)
`
`3
`
`--- VR
`Fig.7b
`
`DISTANCE
`
`X
`
`V2
`
`VI
`
`VL
`
`D
`
`10
`
`ii
`
`7
`
`X
`
`E / 4
`
`/
`
`3
`
`DISTANCE
`
`Fig.7c
`
`SCEA Ex. 1028 Page 5
`
`

`
`U.S. Patent
`
`Jan. 19, 1993
`
`Sheet 5 of 12
`
`5,181,030
`
`Y
`
`6
`
`3
`
`Vi
`
`10
`
`4
`
`fd
`
`0
`
`0
`
`'s e
`--. VR
`
`DISTANCE
`
`X
`
`Fig.8
`
`+V
`
`4
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`3
`
`7
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`11
`
`72
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`
`0
`
`Y AXISE X AXIS
`
`5
`
`ANALOG
`
`SwlTCH - +
`
`A/D
`CONVERTER
`
`Fig.9
`
`SCEA Ex. 1028 Page 6
`
`

`
`+VI
`
`10
`
`4 3
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`
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`
`SWITCH
`
`A/D
`
`CONVERTER
`
`-
`
`Y AXIS
`
`6
`
`X AXIS
`
`10
`
`Fig.
`
`C..4
`so
`
`00
`
`SCEA Ex. 1028 Page 7
`
`

`
`U.S. Patent
`
`Jan. 19, 1993
`
`Sheet 7 of 12
`
`5,181,030
`
`Fig. 11
`
`201
`
`203
`
`201a
`
`214
`
`201b
`
`205
`
`° °/° °
`°
`
`° P
`
`202a
`202
`205
`
`208
`
`._-
`
`Fig. 12
`
`201
`
`208
`
`SCEA Ex. 1028 Page 8
`
`

`
`U.S. Patent
`
`Jan. 19, 1993
`
`Sheet 8 of 12
`
`5,181,030
`
`Y AXIS
`
`X AXIS
`
`219
`
`221
`
`..
`
`215
`
`216
`
`217
`218
`
`220
`
`2010
`
`Fig.13
`
`210
`
`211
`
`204
`
`231
`
`2020
`
`230
`
`Y AXIS
`
`2m
`
`2M
`
`2H
`
`231
`
`X AXIS
`
`Fig.14
`
`SCEA Ex. 1028 Page 9
`
`

`
`U.S. Patent
`
`Jan. 19, 1993
`
`Sheet 9 of 12
`
`5,181,030
`
`Fig. 15
`
`230 223a
`
`A
`
`223
`
`218
`217
`
`21
`215
`
`201b
`
`202a
`
`225
`
`221
`
`214
`
`222
`
`_._.. -202
`
`Fig. 16
`
`223a
`
`224
`
`223
`
`230
`
`230
`
`SCEA Ex. 1028 Page 10
`
`

`
`U.S. Patent
`
`Jan. 19, 1993
`
`Sheet 10 of 12
`
`5,181,030
`
`+v
`
`Fig.17
`
`204
`
`203
`
`207
`
`211
`
`*·n
`
`271
`
`272
`
`V IN
`
`VREF
`
`210
`
`X AXIS
`
`275
`
`203
`
`204
`
`211
`+V
`m3
`
`310
`
`¡¡
`
`+v
`
`314
`
`314
`313
`
`272
`
`VIN
`
`Fig.18
`
`3²
`
`SCEA Ex. 1028 Page 11
`
`

`
`U.S. Patent
`
`Jan. 19, 1993
`
`Sheet 11 of 12
`
`5,181,030
`
`ANALOGMULTIPLEXER
`IAMPX)
`
`325
`
`ANALOG
`SIGNALS
`
`---
`
`---- -o
`321
`322x
`
`323
`
`,
`
`---- -o
`324\
`
`---- -o
`--- --o
`
`(4 SIGNALS) - -o
`-o- -o i --- CH2
`---- CH3
`- -o- -o
`---- CH4
`--- CHS
`-- --- CH6
`--- CH7
`
`CHO
`
`CHI
`
`A
`
`B
`
`D
`
`Fig.19
`.
`
`=o
`gi--- CHANNEL
`m=
`v E
`
`CONTRO
`OUTPUT
`
`SCEA Ex. 1028 Page 12
`
`

`
`U.S. Patent
`
`Jan. 19, 1993
`
`Sheet 12 of 12
`
`5,181,030
`
`ANALOGMULTIPLEXER
`(AMPX)
`
`E
`
`ANALOG
`SIGNALS
`(8 SIGNALS)
`
`o
`°g
`
`0
`
`331
`
`332
`
`333
`
`334
`
`335
`
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`
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`
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`
`338
`
`F i g.20
`
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`c'
`
`CHO
`
`-- - CHI
`-- - CH2
`- - CH3
`- -- CH4
`
`G -
`
`CH5
`
`-- - CH6
`- - CH7
`- CHANNEL
`
`L-
`
`CONTROL
`OUTPUT
`
`SCEA Ex. 1028 Page 13
`
`

`
`1
`
`5,181,030
`
`5
`
`10
`
`20
`
`25
`
`2
`bers of films brings about another troublesomematter
`INPUT SYSTEM INCLUDINGRESISTANCE FILM such as management of various components.
`TOUCH PANEL AND PUSHED POSITION
`SUMMARY OF THE INVENTION
`DETECTING DEVICE
`Accordingly, this invention has an object of offer an
`input system including a resistance film touch panel and
`a pushed position detecting device for accurately de-
`tecting two or more positions pushed simultaneously
`with a minimizednumber of leads.
`The above object is fulfilled by an input system in-
`cluding a resistance film touch panel and a pushed posi-
`tion detecting device for detecting two-dimensional
`coordinatesof a pushed position of a touch panel based
`on surface resistancevalues of resistance films, the sys-
`15 tem comprising a pair of insulating base layers opposed
`to each other with a certain distance therebetween; a
`spacer provided between the insulating base layers for
`keeping the layers apart but for allowing the layers to
`approach each other when an external force is applied
`to one of the layers; a first resistance film extended in
`first and second directions and provided on an inner
`surface of one of the layers, the first and second direc-
`tions crossing each other perpendicularlyand the first
`resistance film having outer connecting electrodes on
`both ends thereof along the second direction; and a
`plurality of secondresistancefilms providedon an inner
`surface of the other of the layers, the second resistance
`films each being a lengthy strip extended in a direction
`crossing the second direction and having first and sec-
`ond outer connectingelectrodes at both ends thereof.
`The second resistance films may be extended in the
`first direction.
`The second resistance films may each have a larger
`resistance value than the first resistance film.
`The system may further comprise a first potential
`supplyingdevice for supplying the first resistancefilm
`with a DC potential through one of the outer connect-
`ing electrodes of the first resistancefilm; a first switch
`electrically connected with all the outer connecting
`electrodes of the second resistance films one by one,
`alternately for the each second resistancefilm; a second
`switch switchedin synchronization with the first switch
`and electrically connectedto the outer connectingelec-
`trode which is opposed to the outer connecting elec-
`trode connected to the first switch; a second potential
`supplying device for supplying the second resistance
`films with a DC potential through the first switch; and
`an electric potential measuring device for measuring
`potentials of the second resistance films through the
`first switch.
`The system may further comprise a DC potential
`supplyingdevice including switchingmeansfor supply-
`ing a DC potential to the second resistancefilms one by
`one; a switching device switching at a speed at least
`twice as high as the DC potential supplying device, the
`switchingdevice being for supplying a DC potential to
`the outer connecting electrodes of the first resistance
`film alternately; and an electric potential measuring
`device for measuring the potential of the outer connect-
`ing electrode of the first resistance film, the electrode
`being opposed to the electrode supplied with the DC
`potential by the switchingdevice.
`The above object may also be fulfilled by an input
`system including a resistance film touch panel and a
`pushed position detecting device for detecting two-di-
`mensionalcoordinates of a pushed position of a touch
`panel based on surface resistance values of resistance
`
`BACKGROUND OF THE INVENTION
`(1) Field of the Invention
`This invention relates to an input system comprisin
`a resistance film touch panel and a device for detecting
`a pushed position of the touch panel, especially the one
`including a device for conducting the above detection
`by use of a change in electric potential which occurs
`when the touch panel is pushed.
`(2) Descriptionof the Prior Art
`A simple input system including a touch panel and a
`detecting device for detecting a pushed position of the
`touch panel and for outputting a signal which indicates
`the two-dimensional coordinates of the position is
`widely used in combination with a character display
`device (CRT, LCD or PDP) or the like.
`In an input system including a resistance film touch
`panel, a pushed position of the touch panel, namely, the
`position where two resistance films are contacted on
`each other, is detected based on the resistancevalue of
`the position-contraryto using capacitance.
`Conventionally, two types of touch panels compris-
`ing resistance films have been offered: analog system
`touch panels and matrix system touch panels.
`FIG. 1 shows an analog system touch panel. Two
`resistance films 91 and 92 are opposed to each other 30
`with a certain distance therebetween. The film 91 has
`outer connecting electrodes 93 and 94 along ends
`thereof, the ends extending along a Y axis; and the·film
`92 has outer connectingelectrodes95 and 96 along ends
`thereof, the ends extending along an X axis. In this 35
`construction,.a pushed position A or B is detected by
`obtaining a resistancevalue ri or r3 between the position
`A or B and the outer connecting electrode 95 and a
`resistancevalue r2or r4 between the position A or B and
`the outer connecting electrode.93 and then converting 40
`the obtained resistance values into a voltage, which is
`outputted through the electrodes 94 or 96
`If the two points A and B are pushed simultaneously,
`ri and r3 are connected in parallel and r2 and r4 are.
`connected in parallel,thereby combined resistances are 45
`formed. The voltage.is divided by the combined resis-
`tances, resulting in finding a position which is neither A
`nor B. Therefore, accurate detection of two pushed
`positions are impossiblewith this construction.
`As shown in FIG. 2, a matrix system touch panel 50
`comprises a plurality of strip-like resistance films 101
`arranged in parallel and a plurality of strip-like resis-
`tance films 102 arranged in parallel. The films 101 are
`extended along the X axis and the films 102 are ex-
`tended along the Y axis, the films 101 and the films 102 55
`having a certain distancetherebetween. A pushed posi-
`tion is detected by finding out which films are contacted
`on each other by use of an appropriatescanner.
`Since each film has a lead connected thereto, a great
`number of leads are necessary,which causes the wiring 60
`area to be too large comparedwith the detection area of
`the touch panel. Also required are a large number of
`input circuit components. These facts increase size of
`the system and manufacturingcost.
`In an effort to minimize the number of the leads, 65
`touch panels are manufactured these days with various
`numbers of films for different usages. However, ·the
`necessityof manufacturing productswith various num-
`
`SCEA Ex. 1028 Page 14
`
`

`
`3
`films, the system comprising a pair of insulating base
`layers opposed to each other with a certain distance
`therebetween; a spacerprovidedbetween the insulating
`base layersfor keeping the layers apart but for allowing
`the layers to approach each other when an external
`force is applied to one of the layers; a first resistance
`film extended in first and second directions and pro-
`vided on an inner surface of one of the layers, the first
`and second directionscrossing each other perpendicu-
`larly and the first resistance film having outer connect-
`ing electrodes on both ends thereof along the second
`direction; and a plurality of second resistance films
`provided on an inner surface of the other of the layers,
`the second resistance films each being a lengthy strip
`extended in a direction crossing the second direction,
`having a first outer connecting electrode at one end
`thereof, and sharing a second outer connecting elec-
`trode with the rest of the second resistancefilms at the
`other end thereof.
`The systemmay further comprise a first DC potential
`supplying device for supplying the first resistancefilm
`with a DC potential through both the outer connecting
`electrodesof the first resistancefilm; a second DC po-
`tential supplying device for supplying a DC potential to
`the second outer connecting electrodes of the second
`resistance films; a switch electrically connected with
`the first outer connecting electrodes of the second resis-
`tance filmsone by one; and an electric potential measur-
`ing device for measuring potentials of the first outer
`connecting electrodes of the second resistance films
`through the switch.
`The above object may also be fulfilled by a resistance
`film touch panel comprisingan upper base layer having
`an upper surface on which an external force is applied
`and a lower surface on which a first resistance film
`extended two-dimensionally is formed; a lower base
`layer opposed to the upper base layer with a certain
`distance therebetweenand having a plurality of lengthy
`strip-like second resistance films formed on a surface
`thereof,the surface being opposed to the lower surface
`of the upper base layer; and a spacer provided between
`the upper and lower base layers for keeping the layers
`apart but for, when the external force is applied on the
`upper base layer, allowingthe first and the second resis-
`tance films to contact each other at a position corre-
`sponding to where the exte.rnal force is applied.
`The upper base layer may be a transparent film and
`the lower base layer is a transparent and hard plate.
`The above object may also be fulfilled by an input
`system including a resistance film touch panel and a
`pushed position detecting device for detecting two-di-
`mensional coordinates of a pushed position of a touch
`panel based on surface resistance values of resistance
`films, the system comprising a pair of insulating base
`layers opposed to each other with a certain distance
`therebetween; a spacer providedbetween the insulating
`base layers for keeping the layers apart but for allowing
`the layers to approach each other when an external
`force is applied to one of the layers; a first resistance
`film extended in first and second directions and pro-
`vided on an inner surface of one of the layers, the first
`and second directions crossing each other perpendicu-
`larly and the first resistance film having outer connect-
`ing electrodes on both ends thereof along the second
`direction; and a plurality of second resistance films
`provided on an inner surface of the other of the layers,
`the second resistance films each being a lengthy strip
`extended in a direction crossing the second direction
`
`65
`
`5,181,030
`
`4
`and having an outer connecting electrode at one end
`thereof.
`The system may further comprise a DC potential
`supplying device for supplying the first resistancefilm
`5 with a DC potential through both the outer connecting
`electrodes thereof; a switching device switched to a
`first state of supplying all the outer connecting elec-
`trodes of the second resistancefilms with a ground-level
`potential and to a second state of releasing the same
`10 from the ground-levelpotential; and an electric poten-
`tial measuringdevice for measuring the potentialsof all
`the outer connecting electrodes of the second resistance
`films both in the first and the second states.
`The pair of insulating base layers may consist of a
`15 flexible upper base layer on which an external force is
`applied and a hard lower base layer opposed to the
`upper base layer with a spacer therebetween, and the
`first resistance film is formed on a lower surface of the
`upper base layer and the second resistance films are
`20 formed on an upper surface of the lower base layer.
`In the above construction,the resistance film on one
`surface is extended two-dimensionally.Since such film
`requires approximately only half electrodes compared
`25 with the matrix system touch panel as well as a smaller
`wiring area and fewer input circuit components,a sim-
`ple construction is obtained with lower manufacturing
`cost. The strip-likeresistance films on the other surface
`are selected one by one, thereby to detect a pushed
`30 position. Even if two or more positions are pushed
`simultaneouslyat least in the first or the second direc-
`tion, the positions are accurately detected.
`Also according to the above construction, the poten-
`tials at both ends of each strip-like resistancefilm are
`35 detected alternately. Even an area defined by two or
`more points is pushed, the outer periphery thereofcan
`be detected with a small number of leads.
`Further, when the touch panel comprises a resistance
`film extended two-dimensionally and formed on the
`40 upper base layer on which an external force is to be
`applied and a plurality of strip-like resistance films
`formed on the lower base layer, the touch panel is easy
`to manufacture and moreover, enhance yield rate for
`the following reason.
`The upper base layer should be thin because it is to be
`pushed by a finger or the like. Much care should be
`takenin formingthe resistance film on such a thin upper
`base layer. Since no laser trimming or other processing
`is necessary in forming the resistance film extended
`50 two-dimensionally in contrast to the strip-like ones,
`there is no worry of spoiling the upper base layer.
`On the other hand, used for the lower base layer is a
`hard and thick plate which is tough enough to with-
`stand laser trimmingfor formingthe strip-likeresistance
`55 fums.
`BRIEF DESCRIPTION OF THE DRAWINGS
`These and other objects,advantages and features of
`the inventionwill become apparent from the following
`60 description thereof taken in conjunction with the ac-
`companying drawings which illustrate specific embodi-
`ments of the invention. In the drawings:
`FIGS. I and 2 are views showing conventional touch
`panels;
`FIG. 2 is a plan view of a touch panel of an embodi-
`ment according to this invention;
`FIG. 4 is a cross sectional view along the A-A line
`of FIG. 3;
`
`45
`
`SCEA Ex. 1028 Page 15
`
`

`
`5,181,030
`
`6
`5
`value of the film 4 of FIG. 5b is four times higher than
`FIGS. So and 5b show examplesof the construction
`that of the film 4 of FIG. Sa. The resistancevalue can
`of a resistancefilm;
`easily become a hundred times or more higher by mak-
`FIG. 6 shows an overall construction of the embodi-
`ing much more cutoffs. This type of resistancefilm is
`ment;
`FIGS. 7a, 7b and 7c show the principle of detecting 5 formed by screen printingor etching when only a small
`number of cutofTs are required, and by photolithogra-
`the pushed position;
`phy or laser processing when a large number of cutoffs
`FIGS. 8, 9 and 10 show other. embodiments of this
`invention;
`are required.
`Each film 4 has outer connecting electrodes 10 and 11
`FIG. 11 is an exploded perspective view of still an-
`10 (formed of silver) at both ends thereof.
`other embodiment of this invention;
`The films 4 may be provided in approximately the
`FIG. 12 is a view of the embodiment of FIG. 11
`same number as the lines or rows of the conventional
`combined with a character display device;
`FIG. 13 is a bottom view of an upper plate of the
`matrix system touch panel.
`The spacers 5 are transparent cylinders formed of an
`embodiment of FIG. 11;
`FIG. 14 is a top view of a lower plate of the embodi- 15 insulating material and are provided in an appropriate
`number at appropriatepositions so that they may not
`ment of FIG. 11;
`prevent the films 3 and 4 from contacting each other
`FIG. 15 is a view showing a printed circuit board of
`when the base film 2 is pushed. The spacers 5 may be
`the system of FIG. 11;
`non-transparentif the spacers 5 are small, and also may
`FIG. 16 is an enlarged view of the part A of FIG. 15;
`FIG. 17 is a view of still another embodimentof this 20 be small dots, globes, or semi-spheres.
`FIG. 6 shows an overall constructionof the embodi-
`invention; and
`FIGS. 18, 19 and 20 are views of modifications of
`ment.
`In FIG. 6, analog switches 41 and 42 have the same
`FIG. 17.
`constructionand are controlled to connect their respec-
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`A first embodiment accordingto this invention will
`be described with reference to FIG. 3 through 8.
`As shown in FIGS. 3 and 4, a touch panel of the
`system comprisestwo insulating base layers 1 and 2, a 30
`resistancefilm 3, a plurality of resistance films 4 (eight
`in this embodiment), and spacers 5 for keeping a certain
`distancebetween the resistancefilms 3 and 4. The films
`3 and 4 are respectively formed on main surfaces la and
`2a of the base layers 1 and 2.
`The insulating base layers 1 and 2 are formed of trans-
`parent polyethylene terephthalete films in this embodi-
`ment. Also employable are glass, plastics and other
`insulatingmaterials which have an appropriate flexibil-
`ity or elasticity.
`The resistance film 3 is extended along the X and Y
`axes crossing each other perpendicularly. The resis-
`tance film 3 desirably has a uniform surface resistance
`value.(will be referred simply to resistancevalue, here-
`inafter) for accurate detectionwith the maximum toler- 45
`ance of ±2E Such a film is produced by sputtering,
`ion-plating or coating an oxide of indium and tin, other
`metals or metal oxides. The resistance film 3 has outer
`connecting electrodes (for example, formed of silver) at
`both ends thereof, the ends extending along the Y axis. 50
`The resistance films 4 are lengthy strips arranged in
`parallel, each film being extended along the X axis. The
`resistancevalue of the film 4 is not required to be uni-
`form but is favorablyten to a hundred timeshigher than
`that of the film 3 so that the resistance value of each film 55
`4 may not affect the electric potential slope of the film
`3 even if the film 4 is contacted on the film 3.
`The resistance films 4 are formed, for example, by
`sputtering an oxide of indium and tin on the surface 2a
`beforeetching.Forming the films 4 of the same material 60
`as the film.3 as in this embodimentgeneratesno problem
`since each film 4 has a bigger resistancevalue due to its
`smaller surface area compared with the film 3. The
`resistance value of each film 4 is further increased by
`making cutoffs 9 from both longer sides thereof alter- 65
`nately (FIG. Sb).With the cutofTs 9, the electric current
`path is halfas wide and twice as long as the current path
`without the cutoffs (FIG. Sa).Therefore, the resistance
`
`m synchronization concerningthe same-numbered ter-
`minals, by the controller 44 through a decoder 45. The
`terminals which are not connected to the terminal 18
`are kept at high impedance.
`In the analog switch 41, the terminal 18 is supplied
`with a DC potential V2 by an external power source,
`and the terminals 2 through 17 are to be connected with
`all the outer connecting electrodes 10 and 11, respec-
`tively. In this construction, V2 is supplied to all
`the
`electrodes 10 and 11 one by one.
`In the analog switch 42, the terminal 1 is supplied
`with a DC potential Vi, and the terminals 2 through 17
`are to be connected with all the electrodes 10 and 11,
`respectively.The terminal 18 is connected to an A/D
`converter 43. In this construction,the potential which is
`supplied to the film 3 through the terminal 1 is output-
`ted as the reference potential, thereafter the electric
`potentials of all the electrodes 10 and 11 are outputted
`one by one.
`The terminals 2 through 17 of both analog switches
`41 and 42 and the electrodes 10 and 11 have such a
`relationship that, while the electric potentials of the
`electrodes 10 and 11 are selectively outputted one by
`one, the analogswitch 41 may apply V2 to the electrode
`belonging to the same film 4 as the selectedone does.
`For measuringthe resistance value, the electrode 6 of
`the film 3 is supplied with V1, and the electrode.7
`is
`grounded. The level of V2 is desirably the same or
`higher than that of Vi.
`The following is how this system is operated.
`The terminals 1 of the analog switches 41 and 42 are
`selected by the command from the decoder 45. The
`terminals 1 and 18 of the analog switch 41 have low
`impedances(ON), but the terminal 1 is connected to
`nothing. Therefore, power is supplied to none of the
`films 4. On the other hand, the terminals 1 and 18 of the
`analog switch 42 are connected to each other. Accord-
`ingly, VI is A/D-convertedby the A/D converter 43
`and sent to the controller 44. The controller 44 stores
`the value of Vi for easy detection of the X coordinate of
`the pushed position.
`Then, the terminals2 of the analogswitches41 and 42
`are selected,thereby the electrode 10 of the uppermost
`
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`film 4 gets V2 through the terminal 18 of the analog
`FIG. 9 shows a second embodiment according to this
`invention. This embodiment is distinct from the first
`switch 41. At this time, the potential of the electrode11
`of the same film 4 is conveyed to the terminals 2 and
`embodiment except the followings.All the films 4 share
`by a common electrode 71 at one ends thereof, the
`then 18, both of the analog switch 42, and to the con-
`troller 44 through the A/D converter 43.
`5 electrode 71 being supplied with the same potential as
`If this potential is the sameor higherthan Vi supplied
`the electrode 6. The potentials of the electrodes 11 are
`to'the film 3, the uppermostfilm 4 is not pushed. In this
`selectively obtained by an analog switch 72. The num-
`ber of the terminals of the analog switch 72 is larger by
`case, the terminals 4 of the analog switches41 and 42
`one than the numberof the films 4.
`thereby the second uppermost film 4 is
`are selected,
`In this construction,if the film 4 is pushedat two or
`pushed or not is detected in the same manner.
`If the potential of the electrode 11 of the uppermost
`more points, only the rightmost point is detected along
`the X axis. Along the Y axis, however,all the coordi-
`film 4 is smaller than V i, the uppermostfilm 4 is pushed.
`nates can be detected by obtaining the potential of each
`In this way, the Y coordinateof the pushed position is
`detected
`FIG. 10 shows a third embodiment according to this
`The X coordinate of the pushed position is detected 15
`e cuodes M are au m be con?M e
`mmo
`in the following way.
`an analog switch 81 and the electrodes 11 are all to be
`FIGS. 7a, 7b and 7c show the relationship between
`connected to an analog switch 82. The analog switches
`the pushed position along the X axis and the potentials
`81 and 82 are controlled to supply V3 to all the films 4
`of the electrodes 6, 7, 10 and 11. The solid line indicates
`the otential slope of the film 3. Concerning each film 4, 20 one by one, m synchromzation concerning each fidm.
`p
`The electrodes 6 and 7 of the film 3 are supplied with
`the electrode101s supplied with V2 and the electrode 11
`V2 through a switch 83, which is switched twice as fast
`has its potential measuredthrough the analog switch 42.
`as the analog switches 81 and 82. The electrodes 6 and
`When the film 4 is not pushed,no power is supplied and
`7 are also connected to the A/D converter through an
`therefore the potential of the electrode 11 is the same as 25 analog switch 84, which is switched as fast as but re-
`V2 of the electrode 10 as shown with the chained line
`versely to the switch 83. The output from the A/D
`(FIG. 7a). As mentioned before, the resistancevalue of
`converter is sent
`to a controller (not shown). The
`the film 4 is too high to have any affect on the potential
`switches 81 through 84 are switched by the controller
`slope of the film 3. Accordingly, when the film 4 is
`through a decoder (not shown).
`pushed and contacted on the film 3 at a pomt C, the 30
`In this construction, when the analog switches81 and
`potential of the point C of the film 4 is lowereddown to
`82 select one of the films 4, the selected film 4 gets the
`Vs, which is the same as that of the corresponding point
`potential slope based on V1. At this time, the potentials
`of the film 3 (the dashed line of FIG. 7a). Then, the
`of the electrodes 6 and 7 are obtained through the ana-
`electrode 11 gets the same potentialVs. The controller
`log switch 84. This operation is repeatedfor all the films
`44 obtains the X coordinate of the point C by use of the 35 4.
`difference between Vs and V j.
`In this way, even if the film 4 is pushed at two or
`If the pushed position is not one point but a wider
`more points along the X axis, all the points can be de-
`area, the detection is done as follows.
`tected. In this embodiment, each film 4 should have a
`In FIG. 7b, points D and E indicate the left end and
`uniform resistance value, which should be ten or a hun-
`the right end of the pushedarea, respectively. As appar- 4e
`dred times lower than that of the film 3.
`ent from FIG. 7b, the electrode 11 gets Va, namely, the
`A fourth embodiment of this invention will be de-
`potential of the point E, based on which the X coordi-
`scribed referring to FIGS. 11 through 14.
`nate of the point E is detected.
`This embodiment includes a touch panel comprising
`After the potential of the electrode 11 is outputted,
`an insulating upper plate 201 to be pushed, an insulating
`the decoder 45 commands the analog switches41 and 42 45
`lower plate 202, a transparent resistance film 203
`to select the terminals 3. By this selection, the electrode
`formed on a lower surface 201a of the plate 201, a plu-
`11 is supplied with V2. On the other hand, the electrode
`rality of transparent resistancefilms 204 formed on an
`10 gets VI, namely, the potentialof point D (FIG. 7c),
`upper surface 202a of the plate 202, a cylindrical spacer
`based on which the X coordinate of the point D is de-
`205 for keeping a certain distance between the resis-
`tected. In this way, the X coordinatesof the two points 50
`tance films 203 and 204, and a printed circuit board 214.
`are detected.
`The system is combined with a characterdisplay 208
`The potentials of the electrodes 10 and 11 of the other
`(CRT, LCD, PDP or EL) as shown in FIG. 12. The
`films 4 are obtained one by one in the same way,
`spacer 205 is formed of an insulating material and may
`whereby the X and Y coordinates of all the points that
`be small dots, globes or semi-spheres.
`define the pushed area are detected.
`The upper plate 201 is formed of a polyethylene te-
`In FIG. 6, a DC power source is connected to the
`rephthalete film in this embodiment, but plastics or
`terminal 18 of the analog switch 41 in order to supply a
`other insulating materials which have an appropriate
`certain level of potential to the film 4 even when the
`flexibility or elasticity can also be used. The upper plate
`film 4 is not pushed and thus to make the unpushed film
`201 has a projecting portion 201b for forming leading
`distinctfrom the pushed film. The analog switch 41 and 60
`electrodes. The lower plate 202 is formed of, for exam-
`the DC power source may be eliminated so as to release
`ple, transparent glass which is excellent in resistance
`the unpushed film from any potential although a little
`against chemicals. Also acceptable are polycarbonate
`unstable electrically.In that case, the electrodes 10 and
`and hard plastics which have excellent resistance
`11 of the pushed film 4 have VI and VR as shown in
`against chemicals and laser.
`FIG. 8. In this construction, the potentials of all the 65
`As shown in FIG. 13, the resistance film 203 is ex-
`electrodes 10 and 11 are selectively obtained by the
`tended along the X and Y axes, which cross each other
`analog switch 42 to detect the X coordinates of the
`perpendicularly. The film 203 is produced in the same
`points D and E.
`way as the film 3 of the first embodiment. The film 203
`
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