Page 12
`
`2 of 4 DOCUMENTS
`
`JP60075927A 1985-O4-30 COORDINATE INPUT DEVICE (en)
`
`English Abstract:
`
`PURPOSE: To improve both the stability of detection and the image resolution by detecting
`the position of coordinates after scanning plural transparent conductor lines of a sensor panel
`and detecting the change of the output addition level.
`
`CONSTITUTION: A sensor panel 10 is formed with X and Y transparent conductor lines 101
`(101aW101m) and 102 (102aW102n) insulating and crossing to each other on a transparent
`substrate. Scanning circuits 11 and 13 consisting of shift registers and drive circuits 12 and 14
`are provided at one side of both lines 101 and 102, respectively. Then the scanning is succes-
`sively carried out with a clock pulse CL. While addition circuits 15 and 16 are set at the other
`side of the lines 101 and 102, respectively. The outputs of the circuits 15 and 16 are delivered
`to a position detecting circuit 17 for detection of the position of coordinates. In this case, the
`electrostatic capacity is applied to the conductor line at a position on the panel 10 where a fin-
`ger, etc. has a touch. The applied drive signal is applied to the circuit 15 via each addition re-
`sistance to obtain X and Y coordinates of an intersecting point.
`
`Applicants/Assignees: FUJITSU KK
`
`Inventors: KURITA SHIYOUICHI
`
`Application Number: JP58184013
`
`Application/Filing Date: 1983-09-30
`
`Classifications:
`
`A
`IPC[]: G06F 3/03
`B
`IPC[]: G06K 11/06
`IPC[8]: G06F3/041 (2006-01-01; C, F, I, 2006-03-10; R, M, JP)
`IPC[8]: G06F3/041 (2006-01-01; A, F, I, 2006-03-10; R, M, JP)
`IPC[8]: G06F3/03 (2006-01-01; C,
`, 1, 2005-11-10; R, M, EP)
`IPC[8]: G06F3/03 (2006-01-01; A,
`, I, 2005-11-10; R, M, EP)
`IPC[8]: G06K11/06 (2006-01-01; c, , 1, 2005-11-10; R, M, EP)
`IPC[8]: G06K11/06 (2006-01-01; A,
`, 1, 2005-11-10; R, M, EP)
`
`Page 1 of 15
`
`Wintek Exhibit 1007
`Wintek Exhibit 1007
`
`

`
`Japanese Laid—0pen Patent Application No. S60—75927
`
`DESCRIPTION
`
`1. Title of the Invention
`
`COORDINATES INPUT DEVICE
`
`2. Claims
`
`(1)
`
`A coordinates input apparatus, comprising:
`a sensor panel including a substrate, a plurality of X side transparent
`conductive lines, and a plurality of Y side transparent conductive lines, both
`
`being disposed on the substrate in an insulated manner relative to each other;
`an X side drive circuit for sequentially driving the plurality of X side
`
`transparent conductive lines;
`a Y side drive circuit for sequentially driving the plurality of Y side
`
`transparent conductive lines;
`an X side adder circuit for adding outputs of the plurality of X side
`
`transparent conductive lines;
`a Y side adder circuit for adding outputs of the plurality of Y side
`
`transparent conductive lines; and
`a position detecting circuit for detecting an output level change of the X
`and Y side adder circuits and detecting a coordinate position indicated by a time
`
`position where the output level change is generated, wherein
`the output
`level change is generated by a change of capacitance
`generated when a desired position on the sensor panel
`is instructed and an
`
`instructed coordinate position is detected.
`
`(2)
`
`The coordinates input apparatus according to claim (1 ), wherein
`an area of an intersection portion between the X side transparent
`
`conductive lines and the Y side transparent conductive lines on the sensor panel
`
`is configured to be smaller than other areas.
`
`The coordinates input apparatus according to any one of claims (1)-(2),
`
`(3)
`wherein
`
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`

`
`in order to detect the output level change, the position detecting circuit is
`configured to delay an output of the adder circuit
`in synchronization with
`scanning of the transparent conductive lines and to obtain a difference between
`
`the delayed output and an output of the adder circuit.
`
`The coordinates input apparatus according to any one of claims (1)-(2),
`
`(4)
`wherein
`
`in order to detect the output level change, the position detecting circuit
`
`stores an output level of a state where a desired position of the sensor panel is not
`instructed and performs a relative comparison between an output level of the
`
`adder circuit and the stored output level-
`
`3. Detailed Description of the Invention
`
`[Technical Field of the Invention]
`The present invention relates to at coordinates input device for detecting
`instructed coordinates using a change of capacitance and more particularly to a
`
`coordinates input device disposed on a surface of a screen of a display device and
`
`suitable for providing an input function to the display device.
`
`[Background of the Technique'_[
`
`With the spread of office automation (DA) in recent years, various types
`
`of terminal devices have been actively used.
`
`In particular, since a display
`
`device appeals to the human sense of sight and is easy to understand intuitively,
`it has been used as an important man—machine interface between a computer and
`
`a human for various types of use including personal computers, word processors,
`
`and online terminals. While such a display device is generally used as an output
`
`device, the display device is also used as an input device instead of a keyboard
`and in some cases, the display device further functions as an inputfoutput device.
`
`[Conventional Technique and the Problem]
`Conventionally, a display has been used as input means i11 a light pen
`
`Specifically, when an electron beam of a Braun tube display illuminates a
`form.
`fluorescent substance on a surface of the Braun tube at a position of a light pen,
`
`the light pen senses this light, and detects, from a time position thereof, a position
`on a screen pointed by the light pen.
`From this, a computer detects which
`
`Page 3 of 15
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`

`
`display content on the display is pointed by the light pen and judges input
`contents. However, such a light pan form can be used only for a scan type
`
`display such as a Broun tube display and may provide uncomfortable feeling to a
`human because a special light pan is used as a tool. Accordingly, in recent
`
`years, touch sensor type displays in which a special coordinates input device is
`disposed on a display screen have been used.
`Such conventional coordinates
`input devices include a light beam matrix form shown in FIG. 1.
`In this form, a
`Y side luminous portion 1
`including a number n of luminous sources DY],
`DY2,
`and DYn is disposed to the left of a display surface 5. On the other
`hand, in a corresponding manner, a Y side light-receiving portion 4 including a
`number n of light—receiving units RY1, RY2,
`and RYn is disposed to the right
`
`In the same manner, an X side luminous portion 2
`of the display surface 5.
`including a number m of luminous sources DXI, DX2,
`and DXm is disposed
`above the display surface 5 and an X side light-receiving portion 3 including a
`number In of light—receiving units RX], RX2,
`and RXm is disposed below the
`
`display surface 5 in a corresponding manner. Then the luminous sources DXI,
`DX2,
`and DXm and DY1, DY2,
`and DYn are sequentially driven in terms
`
`of time to emit a light outside the visible range such as an infrared light beam and
`the light-receiving units disposed in an opposing manner relative to each
`luminous source are caused to receive the lights.
`In this state, when a human
`
`points at a P point on the display surface 5 by the finger, for example, the light
`beams from the luminous sources DX3 and DY3 do not reach the light-receiving
`
`units RX3 and RY3. An instructed position detecting unit 6 detects a level
`
`change resulting from this and detects a coordinate position on the display
`surface 5 pointed by the finger from a time position where the level change has
`occurred.
`
`While this conventional light beam matrix form is simple in theory, it
`
`requires many luminous sources and light-receiving units which are relatively
`large in size. This poses a problem in that a device per se becomes large in size
`and that due to difficulty of integration, the display device gives an impression of
`
`In addition, there is another problem in
`being protruded, which is undesirable.
`that even if a thin stick rather than the human finger is used for pointing in order
`
`to improve resolution, this is impossible due to crosstalk between adjacent light
`
`beams because the light beams are spread.
`
`[Object of the Invention]
`
`Page 4 of 15
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`
`

`
`It is an object of the present invention to provide a coordinates input
`
`device that can be downsized while obtaining high resolution.
`
`[Structure of the Invention]
`
`In order to achieve the above-mentioned object, the present invention
`
`includes: a sensor panel having a substrate, a plurality of X side transparent
`
`conductive lines, and a plurality of Y side transparent conductive lines, both
`
`being disposed on the substrate in an insulated manner relative to each other; an
`
`X side drive circuit for sequentially driving the plurality of X side transparent
`
`conductive lines; a Y side drive circuit for sequentially driving the plurality of Y
`
`side transparent conductive lines; an X side adder circuit for adding outputs of
`
`the plurality of X side transparent conductive lines; a Y side adder circuit for
`
`adding outputs of the plurality of Y side transparent conductive lines; and a
`
`position detecting circuit for detecting an output level change of the X and Y side
`adder circuits and detecting a coordinate position indicated by a time position
`
`where the output level change is generated, wherein the output level change is
`
`generated by a change of capacitance generated when a desired position on the
`
`sensor panel is instructed and an instructed coordinate position is detected.
`
`According to an embodiment of the present invention, an area of an
`
`intersection portion between the X side transparent conductive lines and the Y
`
`side transparent conductive lines on the sensor panel may be configured to be
`smaller than other areas.
`
`According to another embodiment of the present invention, in order to
`
`detect the output level change, the position detecting circuit may be configured to
`
`delay an output of the adder circuit in synchronization with scanning of the
`
`transparent conductive lines and to obtain a difference between the delayed
`
`output and an output of the adder circuit.
`
`According to another embodiment of the present invention, in order to
`
`detect the output level change, the position detecting circuit may store an output
`
`level of a state where a desired position of the sensor panel is not instructed and
`
`perform a relative comparison between an output level of the adder circuit and
`
`the stored output level.
`
`[Embodiment of the Invention]
`
`In the following, the present invention will be described in detail based
`
`on embodiments thereof.
`
`Page 5 of 15
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`
`

`
`FIG. 2 is a diagram showing an entire configuration of an embodiment of
`
`the present invention.
`
`In FIG. 2, numeral 10 designates a sensor pane]. As
`
`shown in a cross-sectional view of a sensor panel in FIG. 3, on a transparent
`
`substrate 100 such as glass, a number m of X side transparent conductive lines
`
`(hereafter referred to as X electrodes) 101a-101m is arranged in parallel with one
`
`another, and a number n of Y side transparent conductive lines (hereafter referred
`
`to as Y electrodes) 102a-l02n is arranged in parallel with one another to cross a
`
`group of the X electrodes
`
`1{)la—101m.
`
`The group of the X electrodes
`
`101a-101m and a group of the Y electrodes 102a-10211 are disposed in an
`
`insulated manner relative to each other. Although the sensor panel 10 is
`
`installed on a screen surface of a display 20 as shown in FIG. 3,
`
`the
`
`above-mentioned transparent substrate 100 may be removed and the group of the
`
`X electrodes and the group of the Y electrodes may be directly disposed on the
`
`screen of the display (a surface of a Braun tube, for example), thereby integrating
`
`the sensor panel 10 with the display. Numeral 11 designates an X side scanning
`
`circuit including a shift register and sequentially scanning the group of the X
`
`electrodes 101a-101m in response to a clock pulse CL. Numeral 12 designates
`
`an X side drive circuit for applying voltage to the group of the X electrodes for
`
`driving in response to the scanning by the X side scanning circuit 11. Numeral
`
`I3 designates a Y side scanning circuit including a shift register and sequentially
`
`scanning the group of the Y electrodes 102a-102n in response to the clock pulse
`
`CL. Numeral 14 designates a Y side drive circuit for applying voltage to the
`
`group of the Y electrodes for driving in response to the scanning by the Y side
`
`scanning circuit 13. These X and Y side scanning circuits 11, 13 and X and Y
`
`side drive circuits 12, 14 constitute a drive circuit. Numeral I5 designates an X
`
`side adder circuit including adder resistances Rla-Rlm connected to each of the
`
`X electrodes 10]a~101m and an operational amplifier 15a for adding outputs of
`
`these adder resistances Rla-Rlm. Numeral 16 designates a Y side adder circuit
`
`including adder resistances R2a-R2n connected to each of the Y electrodes
`
`102a-102n and an operational amplifier 16a for adding outputs of these adder
`
`resistances R2a-R2n. Numeral 1? designates a position detecting circuit for
`
`detecting a coordinate position indicated by the X and Y side adder circuits 15
`and 16.
`
`Next, operations of the embodiment shown in FIG. 2 are described based
`
`on a waveform of each portion in a diagram shown in FIG. 4.
`
`When the clock pulse CL is input to the X and Y side scanning circuits
`
`Page 6 of 15
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`

`
`11 and 13, each of driving signals X1, X2,
`
`and Xm is sequentially applied
`
`from the X side drive ci1'cuit 12 to each of the X electrodes l0la~l01m and, in
`
`the same manner, each of driving signals Y1, Y2,
`
`and Yn is sequentially
`
`applied from the Y side drive circuit 14 to each of the Y electrodes 102a-10211.
`
`While the finger or the like has not touched the sensor panel 10, an
`
`output X0 of the X side adder circuit 15 is constant at —V having an inverted
`polarity of a simple sum of the driving signals X1, X2,
`and Xm as in a solid
`line because the operational amplifier 15a functions as an inverter.
`In the same
`
`manner, an output YO of the Y side adder circuit 16 is constant at —V having an
`
`inverted polarity of a simple sum of the driving signals Y1, Y2,
`solid line.
`
`and Y11 as in a
`
`In this state, when the human finger or the like touches a desired position
`
`on the sensor panel 10, the finger or the like touches an X electrode (10lk, for
`
`example) and an Y electrode (102[, for example) of the desired position, and
`
`capacitance of the human body is applied. Accordingly, driving signals X}: and
`Y1 applied to the X electrode 101;’: and the Y electrode 102! are transferred to
`each of adder resistances Rik and R2! with a dull shape of rising in a waveform.
`
`Accordingly,
`
`in the output X0 of the X side adder circuit 15, a waveform
`
`distortion pxo is generated as shown in a dotted line at a time position txo
`
`corresponding to scanning of the X electrode 101k.
`
`In the same manner, in the
`
`output YO of the Y side adder circuit 16, a waveform distortion pyo is generated
`as shown in a dotted line at a time position tyo corresponding to scanning of the
`
`Y electrode 1021. The position detecting circuit 17 slices the outputs X0 and
`
`Y0 at a predetermined slice level, extracts distortion signals pxo and pyo, and
`
`counts the time positions txo and tyo of the distortion signals pxo and pyo from a
`scanning start time ts, thereby obtaining an X coordinate and a Y coordinate of
`
`an intersection of the electrode 101k and the electrode 102:’ that have been
`
`touched. Accordingly,
`
`it
`
`is possible to detect an instructed position on the
`
`sensor panel 10 by measuring the time positions txo and tyo of the distortion
`
`signals pxo and pyo.
`
`FIG. 5 shows details of the sensor panel 10 configured in FIG. 2. As
`
`shown in FIG. 5-(A), on the transparent substrate 100, an X electrode 101, a Y
`
`ln;;_03) are
`electrode 102, and a transparent conductive film (such as SnO2,
`formed by a method such as sputtering on the 1000
`order. As shown in a
`partial detailed diagram of FIG. 5~(B), at an intersection position of the X
`
`electrode 101 and the Y electrode 102, a transparent
`
`insulating film 103
`
`Page 7 of 15
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`
`

`
`including SiO3 or the like is formed between the X electrode 101 and the Y
`electrode 102 by a method such as sputtering on the 1000
`order. These
`conductive films 101 and 102 and the insulating film 103 are sequentially
`
`prepared on the substrate 100 by a method such as sputtering. On the other
`hand, a transparent conductor film 104 functioning as shielding or grounding is
`formed where necessary over a reverse side of the transparent substrate 100 using
`
`a transparent conductive film such as SnO2, In2O3.
`
`FIG. 6 shows a diagram of an equivalent circuit of the sensor panel 10
`
`The X electrodes 101a-101m are considered here.
`configured in FIG. 2.
`When capacitance between the X electrodes 101a-101m and grounding is Cg,
`coupled capacitance between the X electrode and the Y electrode is Ck, and the
`sum of line resistance r of each of the X electrodes 101a-101m and added
`
`resistance R to be connected thereto is R’, the diagram of an equivalent circuit is
`
`obtained as shown in FIG. 6, where X represents a driving waveform generating
`source.
`
`When a glass thickness of the substrate 100 is 1 mm, a film thickness of
`the X electrode, Y electrode, and the insulating film 103 is 1000 /gt, a width of an
`electrode wire is 1 mm, and a line length is 20 cm, Cg 2 7 PF, Ck 2 350 PF, and r
`
`: 12 K0. While a driving signal (pulse) to be provided to each electrode has
`
`synchronization, it needs to have a cycle sufficiently short relative to a contact
`period of time when a human touches with the finger. This cycle is I msec.
`When a number of each set of electrodes in = n = 300, a period of time when a
`
`single electrode is driven is 3 psec.
`
`On the other hand, from the above-mentioned values, Ck * r = 4.2 usec
`
`and Cg * r = 84 psec. Accordingly,
`
`this state has a problem of crosstalk
`
`resulting from coupling capacitance Ck.
`In other words, the crosstalk occurs
`from the coupled capacitance Ck between the X electrode and the Y electrode.
`The following describes an electrode structure for preventing the crosstalk.
`FIG.
`7 is a diagram showing such an electrode structure. As shown in FIG. ?'-(A)
`and (B), an electrode area of an intersection portion of the X electrode 101 and
`the Y electrode 102 is reduced as represented by W2.
`For example, when a
`
`width of an electrode in the intersection portion is configured to be 0.1 mm, the
`
`coupled capacitance is reduced to 3.5 PF and the crosstalk is less likely to occur.
`On the other hand, when the width of the electrode is reduced, probability that
`
`the finger or the like will touch an electrode is reduced. Accordingly, the width
`of the electrode other than in the intersection portion is configured to be large as
`
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`

`
`In a case of FIG. Tr‘-(I3), in order to
`represented by W1 shown in FIG. ?'—(A).
`further improve contact probability, a triangular contact electrode A is disposed
`on the X electrode 101 and a triangular contact electrode B is disposed on the Y
`
`electrode 102 in an area surrounded by electrodes.
`
`On the other hand, there is a case where the human finger is too thick for
`
`the sensor panel 10 when it is used for CAD (Computer Aided Design) where
`
`coordinates are finely specified and a case where a direct touch on the sensor
`panel 10 by the finger is not desired.
`FIG. 8 is a diagram showing an
`
`instruction input method for such cases.
`As shown in FIG. 8-(A), a thin metal stick 30 is held in the hand and a tip
`
`of the metal stick 30 touches a desired electrode on the sensor panel 10 to cause a
`
`is possible to specify a desired
`it
`In this manner,
`change of capacitance.
`position on the sensor panel 10 with improved accuracy.
`In this case, a contact
`area on the sensor panel 10 is a point contact as in point P since the metal stick
`30 is hard as shown in FIG. 8-(B) and the metal stick 30 may touch only an
`
`added electrode A of the X electrode 101 without touching both of added
`
`electrodes A and B of the X and Y electrodes 10] and 102 at the same time.
`
`FIG. 9 shows an embodiment
`
`in which instruction input means is
`
`improved in consideration of the above-mentioned case. As shown in FIG.
`9-(A), a columnar concavity is formed at a tip of a metal stick 3] and a
`conductive rubber 32 including the columnar concavity is embedded in the metal
`
`stick 31. Since the conductive rubber 32 is relatively soft, when the metal stick
`
`3] is pressed on the sensor panel 10, it is possible to obtain a contact area whose
`diameter is up to that of the conductive rubber 32 as shown in FIG. 9-(B),
`
`thereby solving the problem of FIG. 8-(A).
`
`FIG. 10 is a circuit diagram of an embodiment of the position detecting
`circuit configured in FIG. 2.
`In FIG. 10, while only an X side detection circuit
`is shown, a Y side has the same configuration.
`In FIG. 10, numerals 170 and
`
`171 designate operational amplifiers functioning as a buffer amplifier for a
`storage capacitor Cs. Reference numerals SW1, SW2, and SW3 designate a
`switch and the switches SW1, SW3 and the switch SW2 perform a switching
`
`operation in a complementary manner. The operational amplifiers I70 and 171,
`the switches SW1, SW2, and SW3, and the storage capacitor Cs constitute a two
`
`stage analog shift register. Numeral 172 designates a differential amplifier for
`obtaining a difference AX(t) between an output XO(t-'I‘) of the switch SW1 and
`an output XO(t) of the switch SW3. Numeral I73 designates a comparator for
`
`Page 9 of 15
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`
`

`
`comparing an output AX(t) of the differential amplifier 172 and a reference value
`
`VRJEF and, if the output AX(t) is not less than the VREF, issuing an output pulse.
`
`Numeral 174 designates an AND gate for obtaining a logical AND of a strobe
`
`pulse STROBE and the output pulse- Numeral 175 designates a flip-flop set by
`
`a scanning start signal ST, reset by an output Ptxo of the AND gate 174, and
`
`outputting a gate signal in a time period txo from a scanning start until generation
`
`of the output Ptxo. Numeral 176 designates an AND gate for outputting a clock
`
`pulse CL during a gate signal period. Numeral I77 designates a counter for
`
`counting the clock pulse CL from the AND gate 176 and indicating an X
`
`coordinate (corresponding to the time txo).
`
`Next, operations of the embodiment shown in FIG. 10 are described
`
`based on a waveform of each portion in a diagram shown in FIG. 1 1.
`
`The above-mentioned output X0 of the X side adder circuit 15 is applied
`
`to the switch SW 1. The switch SW 1 and the switch SW 3 perform an onfoff
`
`operation by a clock CL 1 and the switch SW 2 performs an onfoff operation by a
`
`clock CL 2 whose phase is opposite to that of the clock CL 1. Accordingly, the
`
`switches SW 1 and SW 3 and the switch SW 2 are controlled in a complementary
`
`manner. Accordingly, the adder output X0 is delayed by one clock by going
`
`through the operational amplifier 170, the switch SW 2, the operational amplifier
`
`171, and the switch SW 3.
`
`Thus,
`
`the outputs XO(t) and XO(t—T) are input
`
`to the differential
`
`amplifier 172 to obtain the difference AX(t). The difference AX(t) is sliced at
`
`the comparator 173 based on a reference value VREF to be an output pulse.
`
`This output pulse is synchronized with the strobe pulse STROBE at the AND
`
`gate 174 to be a pulse Ptxo. On the other hand, the flip-flop 175 is set by the
`
`scanning start signal ST, opens the AND gate 176, and causes the counter 177 to
`
`count the clock pulse CL (FIG. 4). The above-mentioned pulse Ptxo resets the
`
`flip-flop 175, closes the AND gate 176 to stop input of the clock pulse CL to the
`
`counter 17?.
`
`In accordance with this, the counter 17'? is capable of obtaining a
`
`coordinate value corresponding to the time period txo from the scanning stait
`
`until generation of the pulse Ptxo, thereby detecting an X coordinate. The same
`
`applies to the Y side and so description thereof is omitted.
`
`Since capacitance of
`
`the human body is on the order of 1000 PF to 2000 PF, a time constant of an
`
`electrode at a contact position is temporarily on the order of 12 KQX (1000 PF to
`
`2000 PF) = 12 us to 24 us via the human linger or a conductor. When a driving
`
`pulse width is 3 us, an output of the X and Y electrodes intersecting at the
`
`Page 10 of 15
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`
`

`
`contact position is almost zero.
`
`FIG. 12 is a circuit diagram of another embodiment of the position
`
`detecting circuit configured in FIG. 2.
`
`In FIG. 12, while only the X side is
`
`shown in the same manner as in FIG. 10, the Y side has the same configuration.
`
`In FIG. 12, numeral 180 designates an analog—digital converter (hereafter
`
`referred to as AD converter) for converting a level of the adder output X0 to be
`
`input into a digital value DXO. Numeral 181 designates a memory for storing
`
`an output level of each X electrode in a state where nothing has touched the
`
`sensor panel 10. Numeral 132 designates a memory address circuit for counting
`
`a clock pulse CL (FIG. 4) and generating an address corresponding to a scanned
`electrode position. Numeral 183 designates a readfwrite controlling circuit for
`
`controlling readinglwriting of the memory 181. Numeral 184 designates a
`
`digital comparator for comparing a digital value from the memory 181 and a
`
`digital value from the AD converter 180. Numeral 185 designates an AND gate
`
`for obtaining a logical AND of an output of the digital comparator 184 and a
`
`strobe pulse STROBE. Numeral 186 designates an AND gate for outputting an
`
`address value generated by the address circuit 182 by an output of the AND gate
`
`185. Numeral 187 designates a buffer for storing the address value from the
`
`AND gate 186. Reference numeral SW 4 designates a switch for connecting the
`
`AD converter 180 to the memory 181 or the digital comparator 184.
`
`Next, operations of the embodiment shown in FIG. 12 are described
`
`based on a waveform of each portion in a diagram shown in FIG. 13.
`
`First, the switch SW 4 is connected to the memory 181 and a write mode
`
`is inst1'ucted from the readfwrite controlling circuit 183 to the memory 181.
`
`In
`
`this state where nothing has touched the sensor panel 10, scanning of each of the
`
`above-mentioned X electrodes 101a-101m starts.
`
`In accordance with this, the
`
`adder output X0 is generated from the X side adder circuit 15, an output level
`
`thereof is converted into the digital value DXO at the AD converter 180 and it is
`
`input to the memory 181 via the switch SW 4. The memory address circuit 182
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`counts the same clock pulse CL as a clock pulse CL for causing the scanning
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`circuit 11 (FIG. 2) to perform scanning and provides a write add1'ess to the
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`memory 18]. Consequently, the memory 181 stores output levels when each of
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`the X electrodes l0la—l0lm is actually driven for each of the X electrodes
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`l01a—101m.
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`In this manner, an output level of each electrode when the sensor
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`panel 10 is not touched is read into the memory 181 as a reference value. Next,
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`when coordinates are actually input, the switch SW 4 is connected to the digital
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`comparator 184 and the read/write controlling circuit 183 instructs a read mode
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`to the memory 181.
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`In this state, when the adder output X0 from the adder
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`circuit 15 is input to the AD converter 180, a level thereof is converted into a
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`digital value and it is input to the digital comparator 184. On the other hand,
`the memory address circuit 182 is in synchronization with scanning of the
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`scanning circuit 1 I, the memory address circuit 182 reads from the memory 181
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`the above-mentioned reference value corresponding to a scanned X electrode and
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`The comparator 184
`provides the reference value to the comparator 184.
`compares both inputs and, if the inputs are different, generates an output pulse
`DP.
`FIG. 13 shows that DXO(kT) is read as the reference value from the
`
`memory 181, while the adder output is DXO(k+mT), and a difference AD is
`generated.
`This output pulse DP is synchronized with the strobe pulse
`STROBE at the AND gate 185 and a detected pulse Ptxo is output. On the
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`other hand, since the memory address circuit 182 is in synchronization with the
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`scanning of the scanning circuit 11, the X electrode at that moment, namely, the
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`X coordinate is an address of the memory address circuit 182. Accordingly, the
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`memory address circuit 182 opens the AND gate 136 with the detected pulse
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`Ptxo and sets the address of the memory address circuit 182 in the buffer 187.
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`In this manner, it is possible to obtain the X coordinate corresponding to the time
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`period txo of the detected pulse Ptxo. The same applies to the Y side and so
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`description thereof is omitted. By configuring in this manner it is possible to
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`directly compare levels of each electrode before and after contact, reduce an
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`influence of fluctuation of output levels by each electrode, and improve stability
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`of detection.
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`In addition, it is possible to detect a slight change of capacitance
`
`and perform detection with accuracy.
`
`When a 6-bit parallel AD converter is used as the AD converter, it is
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`possible in theory to easily detect a 2% level difference.
`
`[Effects of the Invention]
`
`As mentioned above,
`
`the present
`
`invention includes: a sensor panel
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`including plural X side transparent conductive lines and plural Y side transparent
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`conductive lines arranged in an insulated manner relative to one other on a
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`substrate; X and Y side drive circuits for sequentially driving each of the plural X
`
`and Y side transparent conductive lines; X and Y side adder circuits for adding
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`outputs of each of the plural X and Y side transparent conductive lines; and a
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`position detecting circuit for detecting an output level change of the X and Y side
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`Page 12 of 15
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`1]
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`adder circuits and detecting specified a coordinate position indicated by a time
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`position where the output level change is generated. The present invention is
`
`configured to cause the output level change by a capacitance change generated
`
`when a desired position of the sensor panel is specified and to detect a specified
`
`coordinate position. Accordingly, it is possible to downsize an apparatus and
`
`provide effects of avoiding spoiling a shape of a display device when the
`
`apparatus is installed on the display device and preventing difficulty in viewing
`
`invention can be integrated with the
`the present
`Further,
`display contents.
`display and provide an input function without showing the presence of a
`
`coordinates input device.
`
`Further, the present invention can be easily integrated
`
`so that a circuit configuration can be downsized. Further, the present invention
`
`u
`
`provides effects of being inexpensively and easily configured since the panel per
`
`se can be prepared in a thin film growth technique such as sputtering suitable for
`
`mass production in addition to providing effects of enabling highly accurate
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`coordinate input such as a CAD system due to easiness of improving resolution.
`
`4. Brief Description of the Drawings
`
`FIG.
`
`1
`
`is a diagram showing a configuration of a conventional
`
`coordinates input device,
`
`FIG. 2 is a diagram showing an entire configuration of an embodiment of
`
`the present invention,
`
`FIG. 3 is a cross-sectional view of a sensor panel configured in FIG. 2,
`
`FIG. 4 is a waveform diagram showing each portion configured in FIG.
`
`FIG. 5 is a diagram showing the details of a configuration of the sensor
`
`panel configured in FIG. 2,
`
`FIG. 6 is a circuit diagram showing an equivalent circuit of the sensor
`
`panel configured in FIG. 2,
`
`FIG. 7 is a diagram illustrating an embodiment of an electrode
`
`configuration of the sensor panel configured in FIG. 2,
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`FIG. 8 is a diagram illustrating an embodiment of an instruction input
`
`method used for the present invention,
`
`FIG. 9 is a diagram illustrating another embodiment of an instruction
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`input method used for the present invention,
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`FIG- 10 is a circuit diagram of an embodiment of a position detecting
`
`Page 13 of 15
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`12
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`circuit configured in FIG. 2,
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`FIG. 11 is a waveform diagram showing each portion configured in FIG.
`
`10,
`
`FIG. 12 is a circuit diagram of another embodiment of the position
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`detecting circuit configured in FIG. 2, and
`
`FIG. 13 is a waveform diagram showing each portion configured in FIG.
`
`12.
`
`10
`
`11
`12
`
`13
`
`14
`
`15
`
`16
`
`17
`
`sensor panel
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`X side scanning circuit
`X Side drive circuit
`
`Y side scanning circuit
`
`Y side drive circuit
`
`X side adder circuit
`
`Y side adder circuit
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`position detecting circuit
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`101a-101m
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`X side transparent conductive lines
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`102a-102n
`
`Y side transparent conductive lines
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`Page 14 of 15
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`1'SAM}CHu SIIIEI
`1-til-91-6£Il!v9133
`JU.|nSl50pm||.:otn
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`TRANSLATION CERTIFICATION
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