JP3750212B2 - Coordinate position input device - Google Patents

Description

【０００８】
そして制御部４１４は、制御信号４１５で選択部４０４，４０５の選択を抵抗体Ｓ１にさせ、制御信号４１６で駆動部４０６，４０７の設定を基準電圧Ｅ１側とさせると、容量Ｃに印加される電圧はＥ１となり電荷が充電される。この状態で駆動部４０６，４０７の設定を基準電圧Ｅ２側に切替えると、Ｅ１＞Ｅ２の時は容量Ｃの電荷が電圧Ｅ２になるまでＲ１，Ｒ２を通して放電される。この時Ｒ１を流れる電流をＩ１，Ｒ２を流れる電流をＩ２とすると、Ｉ１×Ｒ１＝Ｉ２×Ｒ２なので、次の（数２）に示す関係が成り立つ。
【０００９】
【数２】

【００１０】
ここで（数１）、（数２）より次の（数３）に示す関係が成り立つ。
【００１１】
【数３】

【００１２】
よって電流Ｉ１とＩ２の比によってＹ軸方向の操作者の指の座標位置がわかる。
【００１３】
また、Ｅ１＜Ｅ２の時は容量Ｃの電荷が電圧Ｅ２になるまでＲ１，Ｒ２を通して充電されるので、Ｉ１，Ｉ２は方向が逆になり−Ｉ１，−Ｉ２となるが（数２）は成り立つので、Ｅ１＜Ｅ２としてもよい。
【００１４】
そして、Ｉ１，Ｉ２はＩ／Ｖ変換部４１０，４１１でそれぞれ電圧値に変換され、Ａ／Ｄ変換部４１２，４１３でそれぞれデジタル値に変換され、制御部４１４へ入力され、この制御部４１４でＹ軸方向の操作者の指４０１の座標位置を計算する。
【００１５】
続いて制御部４１４は、制御信号４１５で選択部４０４，４０５の選択を抵抗体Ｓ２，Ｓ３……Ｓｎと順次切替えを行いながら、上記と同じように制御信号４１６で駆動部４０６，４０７を制御し、抵抗体Ｓ２，Ｓ３……Ｓｎそれぞれにおける電流Ｉ１，Ｉ２を検出することができるので、操作者の指４０１が抵抗体Ｓ１以外の抵抗体の位置にあってもＹ軸方向の操作者の指４０１の座標位置を計算することができる。
【００１６】
次に、Ｘ軸方向の位置検出原理を以下に説明する。
まず、時間をｔ、容量Ｃに発生する電圧をＶ、容量Ｃを流れる電流をＩとすると次の（数４）に示す微分方程式が成り立つ。
【００１７】
【数４】

【００１８】
ここでＩ＝Ｉ１＋Ｉ２なので、Ｉ１＋Ｉ２＝Ｃ×（ｄＶ／ｄｔ）となり、これによって電流Ｉ１とＩ２の和で容量Ｃの大きさがわかる。
【００１９】
そして、制御部４１４は制御信号４１５で選択部４０４，４０５の選択を抵抗体Ｓ２，Ｓ３……Ｓｎと順次行って各々の電流Ｉ１とＩ２を検出し、その和の大きさを比較計算または補間計算して容量Ｃの分布状態を算出する。通常容量Ｃの分布状態は、操作者の指４０１による影響が無い位置では容量Ｃ＝０、操作者の指４０１による影響が最も大きい位置の容量Ｃは最大の分布となるので制御部４１４は、算出した容量Ｃが最大となった位置を指４０１での操作位置と判定する。
【００２０】
このようにして抵抗体Ｓ１からＳｎまで検出したそれぞれの抵抗体での電流Ｉ１とＩ２の和の大きさを比較計算または補間計算することによって、Ｘ軸方向の操作者の指４０１の座標位置を求めることができる。
【００２１】
【発明が解決しようとする課題】
しかしながら上記従来の構成では、Ｘ軸方向の操作者の指４０１の座標位置の検出精度は分割した抵抗体Ｓｎの本数に依存し、検出精度をあげるためには操作者の指４０１の大きさに対して十分細かい間隔で抵抗体４００を配置する必要があるが、抵抗体４００の分割本数を多くすると検出に時間がかかるという課題を有していた。
【００２２】
本発明は上記従来の課題を解決するものであり、従来に比べて座標位置検出時間を大幅に短縮することができる優れた座標位置入力装置を提供することを目的とするものである。
【００２３】
【課題を解決するための手段】
この課題を解決するために本発明の座標位置入力装置は、ＸＹ直交座標平面のＸ軸方向検出用として、複数の帯状の第一の抵抗体を配するとともに、Ｙ軸方向検出用として、前記複数の帯状の第一の抵抗体間各々に配置した複数の帯状部の両端を連結部で結んだはしご状の第二の抵抗体を配置した検出部を有する構成としたものである。
【００２４】
この本発明によれば、座標位置検出時間を大幅に短縮することができる優れた座標位置入力装置を得ることができる。
【００２５】
【発明の実施の形態】
本発明の請求項１に記載の発明は、複数本が所定の間隔で配置されて各両端が対向して配置された一対の帯状の第１電極にそれぞれ接続された帯状の第１の抵抗体、ならびにこの複数の帯状の第１の抵抗体の外方にそれぞれ第１の抵抗体と平行に配置された一対の帯状の第２電極の各両端どうしを上記第１電極の外方で接続する抵抗体からなる一対の帯状の連結部にそれぞれの両端が接続されて上記第１の抵抗体間に各々絶縁状態で配置された帯状の第２の抵抗体により構成されて座標位置を入力操作する検出部と、この検出部の選択を行う選択部と、上記検出部を駆動する駆動部と、上記検出部からの電流信号を電圧信号に変換するＩ／Ｖ変換部と、上記電圧信号をデジタル信号に変換するＡ／Ｄ変換部と、上記デジタル信号から座標位置を求める制御部からなる構成としたものであり、座標位置検出のための切替え回数は最低２回で済むため、検出時間を大幅に短くできるという作用を有する。
【００２６】
請求項２に記載の発明は、請求項１記載の発明において、帯状の第二の抵抗体を導体により形成したものであり、座標位置検出のための切替え回数は最低２回で済み、さらに第二の抵抗体の複数の帯状部を導体にて形成したため信号の遅れが無く、検出時間をより短くできるという作用を有する。
【００２７】
以下、本発明の実施の形態について図１、図２を用いて説明する。
（実施の形態１）
図１は本発明の第１の実施の形態による座標位置入力装置の構成を示す概念図、図２は同検出部の構成を示す平面図であり、同図において、１は複数の帯状の第一の抵抗体であり、この複数の第一の抵抗体１は対向する一対の対辺に設けた第一電極２，３で互いに接続されている。そして、４ははしご状の第二の抵抗体であり、その形状は、上記第一の抵抗体１間に配され、上記第一電極２，３の外方まで伸び、第一電極２，３と絶縁された複数の帯状部４Ａと、この帯状部４Ａの両端を各々結ぶ連結部４Ｂからなっている。そして、６，７は第二の抵抗体４の連結部４Ｂと直交する対向した外周の一対の対辺に設けた第二電極であり、上記の構成によって座標位置を入力操作する検出部を構成している。
【００２８】
８は操作者の指、９は回路グラウンド、１０は操作者の指８によって第一の抵抗体１と回路グラウンド９との間に見掛け上形成される静電容量、１１は操作者の指８によって第二の抵抗体４の帯状部４Ａと回路グラウンド９との間に見掛け上形成される静電容量、１２，１３は第一、第二の抵抗体１，４の選択部、１４，１５は第一、第二の抵抗体１，４の駆動部、１６，１７は基準電圧、１８，１９は電流を電圧に変換するＩ／Ｖ変換部、２０，２１は電圧をデジタル値に変換するＡ／Ｄ変換部、２２は制御部、２３は選択部１２，１３の制御信号、２４は駆動部１４，１５の制御信号である。
【００２９】
また、Ｘ，Ｙは直交座標平面の軸であり、説明がしやすいように第一の抵抗体１はＸ軸と平行に、第二の抵抗体４の連結部４ＢはＹ軸と平行に配置したものとする。
【００３０】
以下に、このように構成した座標位置入力装置の動作について説明するが、図１に示すように、操作者の指８によって抵抗体１と回路グラウンド９との間及び、第二の抵抗体４の帯状部４Ａと回路グラウンド９との間に、見掛け上静電容量１０，１１が形成され、ここで、この静電容量１０の大きさをＣｘ、静電容量１１の大きさをＣｙとする。
【００３１】
また、基準電圧１６の大きさをＥ１、基準電圧１７の大きさをＥ２とする。
最初に操作者の指８が、図１に示すように、第一の抵抗体１のＸ軸方向のｘ１：ｘ２となる位置にある場合のＸ軸方向の位置検出原理を以下に説明する。
【００３２】
まず、複数の第一の抵抗体１は第一電極２，３によって互いに接続されているので第一電極２，３からみると１本の抵抗とみなすことができ、このときの第一の抵抗体１のｘ１側の抵抗体部分を２５とし、その抵抗値をＲｘ１、ｘ２側の抵抗体部分を２６とし、その抵抗値をＲｘ２とすると次の（数５）に示す関係が成り立つ。
【００３３】
【数５】

【００３４】
そして制御部２２は、制御信号２３によって選択部１２，１３の選択を第一の抵抗体１側に切替えるとともに、制御信号２４によって駆動部１４，１５の設定を基準電圧Ｅ１側に切替えを行って、容量Ｃｘに電圧Ｅ１を印加する。
【００３５】
次に、同様にしてこの状態で駆動部１４，１５の設定を基準電圧Ｅ２側に切替えると、Ｅ１＞Ｅ２の時は容量Ｃｘの電荷が電圧Ｅ２になるまでｘ１，ｘ２側抵抗体部分２５，２６を通して放電される。この時ｘ１側抵抗体部分２５を流れる電流をＩｘ１、ｘ２側抵抗体部分２６を流れる電流をＩｘ２とすると、Ｉｘ１×Ｒｘ１＝Ｉｘ２×Ｒｘ２であるため、次の（数６）に示す関係が成り立つ。
【００３６】
【数６】

【００３７】
また、（数５）、（数６）より次の（数７）に示す関係が成り立つ。
【００３８】
【数７】

【００３９】
この（数７）によれば、電流Ｉｘ１とＩｘ２の比によってＸ軸方向の操作者の指８の座標位置を検出できることがわかる。
【００４０】
また、Ｅ１＜Ｅ２の時は容量Ｃｘの電荷が電圧Ｅ２になるまでｘ１，ｘ２側抵抗体部分２５，２６を通して充電されるので、電流Ｉｘ１，Ｉｘ２は方向が逆になって−Ｉｘ１，−Ｉｘ２となるが、（数６）は同様に成り立つため、Ｅ１＜Ｅ２としてもよい。
【００４１】
そして、電流Ｉｘ１，Ｉｘ２をＩ／Ｖ変換部１８，１９でそれぞれ電圧値に変換し、更に、Ａ／Ｄ変換部２０，２１でそれぞれデジタル値に変換して、制御部２２に入力させて、制御部２２で両者を比較演算することによって操作者の指８のＸ軸方向の座標位置を検出するようになっている。
【００４２】
次に、操作者の指８が図１に示すように第二の抵抗体４の帯状部４ＡのＹ軸方向のｙ１：ｙ２となる位置にある場合のＹ軸方向の位置検出原理を以下に説明する。
【００４３】
このとき、容量Ｃｙは操作者の指８の面積によって第二の抵抗体４の帯状部４Ａの最低１本以上で分割して形成される形となるが、その複数本の帯状部４Ａから連結部４Ｂ各々に加わる電荷量は分割形成された容量の大きさに比例するため、第二の抵抗体４の連結部４Ｂでの容量Ｃｙの容量的中心位置はｙ１：ｙ２の位置を操作したことと同様に考えることができる。
【００４４】
また、第二の抵抗体４の連結部４Ｂは第二電極６，７からみると１本の抵抗とみなすことができ、そのｙ１側の抵抗体部分を２７とし、その抵抗値をＲｙ１、ｙ２側の抵抗体部分を２８とし、その抵抗値をＲｙ２とすると次の（数８）に示す関係が成り立つ。
【００４５】
【数８】

【００４６】
そして制御部２２は、制御信号２３によって選択部１２，１３の選択を第二の抵抗体４側に切替えるとともに、制御信号２４によって駆動部１４，１５の設定を基準電圧Ｅ１側に切替えを行って、容量Ｃｙに電圧はＥ１を印加する。
【００４７】
次に、同様にしてこの状態で駆動部１４，１５の設定を基準電圧Ｅ２側に切替えると、Ｅ１＞Ｅ２の時は容量Ｃｙの電荷が電圧Ｅ２になるまでｙ１，ｙ２側抵抗体部分２７，２８を通して放電される。この時ｙ１側抵抗体部分２７を流れる電流をＩｙ１、ｙ２側抵抗体部分２８を流れる電流をＩｙ２とすると、Ｉｙ１×Ｒｙ１＝Ｉｙ２×Ｒｙ２であるため、次の（数９）に示す関係が成り立つ。
【００４８】
【数９】

【００４９】
また、（数８）、（数９）より次の（数１０）に示す関係が成り立つ。
【００５０】
【数１０】

【００５１】
この（数１０）によれば、電流Ｉｙ１とＩｙ２の比によってＹ軸方向の操作者の指８の座標位置を検出できることがわかる。
【００５２】
また、Ｅ１＜Ｅ２の時は容量Ｃｙの電荷が電圧Ｅ２になるまでｙ１，ｙ２側抵抗体部分２７，２８を通して充電されるので、電流Ｉｙ１，Ｉｙ２は方向が逆になって−Ｉｙ１，−Ｉｙ２となるが、（数９）は同様に成り立つため、Ｅ１＜Ｅ２としてもよい。
【００５３】
そして、電流Ｉｙ１，Ｉｙ２をＩ／Ｖ変換部１８，１９でそれぞれ電圧値に変換し、更にＡ／Ｄ変換部２０，２１でそれぞれデジタル値に変換して、制御部２２に入力させて、制御部２２で両者を比較演算することによって操作者の指８のＹ軸方向の座標位置を検出するようになっている。
【００５４】
以上のように本発明の座標位置入力装置は、切替え動作を最低２回行うだけで座標位置を検出できるようにしたため、検出時間は短くて済むとともに、選択部１２，１３も小さいものでよいものとなる。
【００５５】
（実施の形態２）
本発明の第２の実施の形態は、前述の実施の形態１の座標位置入力装置の第二の抵抗体４の帯状部４Ａを抵抗体にて形成する代わりに導体によって形成した構成となっているものである。
【００５６】
このように第二の抵抗体４の複数の帯状部４Ａを導体で形成すると、容量Ｃｙの電荷の連結部４Ｂに移動する時の遅れを無くすことができるため、Ｙ軸方向の検出時間を短縮する場合には特に有用である。
【００５７】
【発明の効果】
以上のように本発明によれば、座標位置の検出を短時間で行うことができ、その構成回路も小さくて済む優れた座標位置入力装置を実現できるという有用な効果が得られる。
【図面の簡単な説明】
【図１】本発明の第一の実施の形態による座標位置入力装置の構成を示す概念図
【図２】同検出部の構成を示す平面図
【図３】従来の座標位置入力装置の構成を示す概念図
【符号の説明】
１ 第一の抵抗体
２，３ 第一電極
４ 第二の抵抗体
４Ａ 第二の抵抗体の帯状部
４Ｂ 第二の抵抗体の連結部
６，７ 第二電極
８ 操作者の指
９ 回路グラウンド
１０，１１ 見掛け上形成される静電容量
１２，１３ 第一、第二の抵抗体の選択部
１４，１５ 第一、第二の抵抗体の駆動部
１６，１７ 基準電圧
１８，１９ Ｉ／Ｖ変換部
２０，２１ Ａ／Ｄ変換部
２２ 制御部
２３ 選択部の制御信号
２４ 駆動部の制御信号
２５ ｘ１側抵抗体部分
２６ ｘ２側抵抗体部分
２７ ｙ１側抵抗体部分
２８ ｙ２側抵抗体部分[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coordinate position input device used for inputting a screen cursor coordinate position of an information device.
[0002]
[Prior art]
The conventional technique will be described with reference to FIG.
[0003]
FIG. 3 is a conceptual diagram showing the configuration of a conventional coordinate position input device. In FIG. 3, 400 is a plurality of strip resistors, 401 is an operator's finger, 402 is a circuit ground, and 403 is an operator's finger 401. Capacitance formed apparently between the resistor 400 and the circuit ground 402, 404 and 405 are the selection units of the resistor 400, 406 and 407 are the drive units of the resistor 400, and 408 and 409 are the drive units 406 and 406. Reference voltage 407, 410 and 411 are I / V converters for converting current into voltage, 412 and 413 are A / D converters for converting voltage into digital values, 414 is a control unit, 415 is selection units 404 and 405 The control signal 416 is a control signal for the drive units 406 and 407.
[0004]
In addition, X and Y are axes on an orthogonal coordinate plane. For ease of explanation, a single resistor 400 is Sn (n = 1, 2,... N), and the divided resistor Sn is shown in FIG. Thus, it is assumed that they are arranged along the X axis in parallel with the Y axis. The capacitance 403 is C, the reference voltage 408 is E1, and the reference voltage 409 is E2.
[0005]
In the conventional coordinate position input apparatus configured as described above, the position detection in the Y-axis direction when the operator's finger 401 is at the position of y1: y2 in the Y-axis direction of the resistor S1 as shown in FIG. The principle will be described below.
[0006]
First, when the resistance value on the y1 side of the resistor S1 is R1, and the resistance value on the y2 side is R2, the relationship shown in the following (Equation 1) is established.
[0007]
[Expression 1]

[0008]
The control unit 414 applies the selection to the capacitor C when the selection unit 404, 405 is selected by the control signal 415 to the resistor S1 and the drive unit 406, 407 is set to the reference voltage E1 side by the control signal 416. The voltage becomes E1 and charges are charged. When the setting of the drive units 406 and 407 is switched to the reference voltage E2 side in this state, when E1> E2, the charge of the capacitor C is discharged through R1 and R2 until the voltage E2 is reached. At this time, assuming that the current flowing through R1 is I1 and the current flowing through R2 is I2, since I1 × R1 = I2 × R2, the following relationship is established.
[0009]
[Expression 2]

[0010]
Here, the relationship shown in the following (Equation 3) holds from (Equation 1) and (Equation 2).
[0011]
[Equation 3]

[0012]
Therefore, the coordinate position of the operator's finger in the Y-axis direction can be determined by the ratio of the currents I1 and I2.
[0013]
When E1 <E2, the charge of the capacitor C is charged through R1 and R2 until the voltage E2 reaches the voltage E2. Therefore, the directions of I1 and I2 are reversed and become −I1 and −I2 (Equation 2) holds. Therefore, it is good also as E1 <E2.
[0014]
I1 and I2 are converted into voltage values by the I / V conversion units 410 and 411, respectively, converted into digital values by the A / D conversion units 412 and 413, and input to the control unit 414. The control unit 414 The coordinate position of the finger 401 of the operator in the Y-axis direction is calculated.
[0015]
Subsequently, the control unit 414 controls the driving units 406 and 407 with the control signal 416 in the same manner as described above while sequentially switching the selection of the selection units 404 and 405 with the resistors S2, S3... Sn with the control signal 415. Since the currents I1, I2 in the resistors S2, S3... Sn can be detected, even if the operator's finger 401 is at a resistor other than the resistor S1, the operator in the Y-axis direction The coordinate position of the finger 401 can be calculated.
[0016]
Next, the principle of position detection in the X-axis direction will be described below.
First, when the time is t, the voltage generated in the capacitor C is V, and the current flowing through the capacitor C is I, the following differential equation is established.
[0017]
[Expression 4]

[0018]
Here, since I = I1 + I2, I1 + I2 = C × (dV / dt), and the magnitude of the capacitance C can be found by the sum of the currents I1 and I2.
[0019]
Then, the control unit 414 detects the currents I1 and I2 by sequentially selecting the selection units 404 and 405 with the resistors S2, S3... Sn in response to the control signal 415, and compares or calculates the magnitude of the sum. The distribution state of the capacity C is calculated by calculation. The distribution state of the normal capacity C is such that the capacity C = 0 at a position where there is no influence by the operator's finger 401, and the capacity C at the position where the influence by the operator's finger 401 is the largest has a maximum distribution. The position where the calculated capacity C is maximized is determined as the operation position with the finger 401.
[0020]
By comparing or interpolating the sum of the currents I1 and I2 in the respective resistors detected from the resistors S1 to Sn in this way, the coordinate position of the operator's finger 401 in the X-axis direction can be determined. Can be sought.
[0021]
[Problems to be solved by the invention]
However, in the conventional configuration described above, the detection accuracy of the coordinate position of the operator's finger 401 in the X-axis direction depends on the number of divided resistors Sn, and the size of the operator's finger 401 is increased in order to increase the detection accuracy. On the other hand, it is necessary to dispose the resistors 400 at sufficiently fine intervals, but there is a problem that it takes time to detect if the number of divided resistors 400 is increased.
[0022]
The present invention solves the above-described conventional problems, and an object of the present invention is to provide an excellent coordinate position input device capable of significantly shortening the coordinate position detection time as compared with the prior art.
[0023]
[Means for Solving the Problems]
In order to solve this problem, the coordinate position input device of the present invention includes a plurality of strip-shaped first resistors for detecting the X-axis direction of the XY orthogonal coordinate plane, and for detecting the Y-axis direction. It has a configuration having a detection unit in which a ladder-like second resistor is arranged in which both ends of a plurality of strips arranged between each of the plurality of belt-like first resistors are connected by a connecting part.
[0024]
According to the present invention, it is possible to obtain an excellent coordinate position input device capable of greatly shortening the coordinate position detection time.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 of the present invention is a strip-shaped first resistor connected to a pair of strip-shaped first electrodes in which a plurality of strips are arranged at predetermined intervals and both ends thereof are opposed to each other. In addition, both ends of a pair of strip-shaped second electrodes arranged in parallel to the first resistor are connected to the outside of the plurality of strip-shaped first resistors, respectively, outside the first electrode. Both ends are connected to a pair of strip-shaped connecting portions made of resistors, and the coordinate position is input by being constituted by a strip-shaped second resistor disposed in an insulated state between the first resistors. A detection unit; a selection unit that selects the detection unit; a drive unit that drives the detection unit; an I / V conversion unit that converts a current signal from the detection unit into a voltage signal; and A / D converter for converting to signal and coordinate position from the above digital signal Is obtained by a structure comprising a control unit for determining, for the number of times switching for the coordinate position detection requires only a minimum of two times, an effect that the detection time can be greatly shortened.
[0026]
The invention according to claim 2 is the invention according to claim 1, wherein the strip-shaped second resistor is formed of a conductor, and the number of times of switching for detecting the coordinate position is at least two times. Since the plurality of strips of the second resistor are formed of a conductor, there is no signal delay and the detection time can be shortened.
[0027]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
(Embodiment 1)
FIG. 1 is a conceptual diagram showing the configuration of the coordinate position input apparatus according to the first embodiment of the present invention. FIG. 2 is a plan view showing the configuration of the detection unit. In FIG. The plurality of first resistors 1 are connected to each other by first electrodes 2 and 3 provided on a pair of opposite sides facing each other. Reference numeral 4 denotes a ladder-like second resistor, and the shape thereof is arranged between the first resistors 1 and extends to the outside of the first electrodes 2, 3. And a plurality of strip portions 4A insulated from each other, and a connecting portion 4B that connects both ends of the strip portion 4A. Reference numerals 6 and 7 denote second electrodes provided on a pair of opposing opposite sides that are orthogonal to the connecting portion 4B of the second resistor 4, and constitute a detection unit that inputs and operates the coordinate position by the above configuration. ing.
[0028]
8 is an operator's finger, 9 is a circuit ground, 10 is an electrostatic capacitance apparently formed between the first resistor 1 and the circuit ground 9 by the operator's finger 8, and 11 is an operator's finger 8 , The apparent capacitance formed between the belt-like portion 4A of the second resistor 4 and the circuit ground 9, 12 and 13 are selection portions of the first and second resistors 1 and 4, and 14 and 15 respectively. Is a drive unit for the first and second resistors 1 and 4, 16 and 17 are reference voltages, 18 and 19 are I / V converters for converting current into voltage, and 20 and 21 are for converting voltage into digital values. An A / D conversion unit, 22 is a control unit, 23 is a control signal for the selection units 12 and 13, and 24 is a control signal for the drive units 14 and 15.
[0029]
X and Y are axes on an orthogonal coordinate plane, and the first resistor 1 is arranged in parallel with the X axis, and the connecting portion 4B of the second resistor 4 is arranged in parallel with the Y axis for easy explanation. Shall be.
[0030]
Hereinafter, the operation of the coordinate position input apparatus configured as described above will be described. As shown in FIG. 1, the second resistor 4 between the resistor 1 and the circuit ground 9 and by the operator's finger 8. Apparent capacitances 10 and 11 are formed between the belt-like portion 4A and the circuit ground 9, where the capacitance 10 is Cx, and the capacitance 11 is Cy. .
[0031]
Also, the magnitude of the reference voltage 16 is E1, and the magnitude of the reference voltage 17 is E2.
First, the principle of detecting the position in the X-axis direction when the operator's finger 8 is at the position of x1: x2 in the X-axis direction of the first resistor 1 as shown in FIG. 1 will be described below.
[0032]
First, since the plurality of first resistors 1 are connected to each other by the first electrodes 2 and 3, they can be regarded as one resistor when viewed from the first electrodes 2 and 3. When the resistance part on the x1 side of the body 1 is 25, the resistance value is Rx1, the resistance part on the x2 side is 26, and the resistance value is Rx2, the following relationship (Equation 5) holds.
[0033]
[Equation 5]

[0034]
The control unit 22 switches the selection of the selection units 12 and 13 to the first resistor 1 side by the control signal 23 and switches the setting of the drive units 14 and 15 to the reference voltage E1 side by the control signal 24. The voltage E1 is applied to the capacitor Cx.
[0035]
Next, when the setting of the driving units 14 and 15 is similarly switched to the reference voltage E2 side in this state, when E1> E2, the x1, x2 side resistor parts 25, until the electric charge of the capacitor Cx becomes the voltage E2. 26 is discharged. At this time, assuming that the current flowing through the x1-side resistor portion 25 is Ix1, and the current flowing through the x2-side resistor portion 26 is Ix2, since Ix1 × Rx1 = Ix2 × Rx2, the relationship shown in the following (Equation 6) holds. .
[0036]
[Formula 6]

[0037]
Further, the following relationship is established from (Equation 5) and (Equation 6).
[0038]
[Expression 7]

[0039]
According to this (Equation 7), it can be seen that the coordinate position of the operator's finger 8 in the X-axis direction can be detected by the ratio of the currents Ix1 and Ix2.
[0040]
Further, when E1 <E2, since the charge of the capacitor Cx is charged through the x1 and x2 side resistor portions 25 and 26 until the voltage E2 is reached, the directions of the currents Ix1 and Ix2 are reversed and −Ix1 and −Ix2 However, since (Equation 6) holds similarly, E1 <E2 may be satisfied.
[0041]
The currents Ix1 and Ix2 are converted into voltage values by the I / V converters 18 and 19, respectively, and further converted into digital values by the A / D converters 20 and 21, respectively, and input to the controller 22, The control unit 22 compares the two to detect the coordinate position of the operator's finger 8 in the X-axis direction.
[0042]
Next, the principle of detecting the position in the Y-axis direction when the operator's finger 8 is in the position of y1: y2 in the Y-axis direction of the strip 4A of the second resistor 4 as shown in FIG. explain.
[0043]
At this time, the capacitor Cy is formed by dividing at least one of the strips 4A of the second resistor 4 according to the area of the finger 8 of the operator, and is connected from the plurality of strips 4A. Since the amount of charge applied to each of the portions 4B is proportional to the size of the divided capacitance, the capacitive center position of the capacitance Cy at the connection portion 4B of the second resistor 4 is operated at the position of y1: y2. Can be thought of as well.
[0044]
Further, the connecting portion 4B of the second resistor 4 can be regarded as one resistor when viewed from the second electrodes 6 and 7, the resistor portion on the y1 side is 27, and the resistance values thereof are Ry1, y2 If the resistor portion on the side is 28 and the resistance value is Ry2, the following relationship is established.
[0045]
[Equation 8]

[0046]
The control unit 22 switches the selection of the selection units 12 and 13 to the second resistor 4 side by the control signal 23, and switches the setting of the drive units 14 and 15 to the reference voltage E1 side by the control signal 24. The voltage E1 is applied to the capacitor Cy.
[0047]
Next, when the setting of the drive units 14 and 15 is switched to the reference voltage E2 side in this state in the same manner, when E1> E2, the y1, y2 side resistor portions 27, 27 are changed until the charge of the capacitor Cy becomes the voltage E2. 28 is discharged. At this time, assuming that the current flowing through the y1 side resistor portion 27 is Iy1, and the current flowing through the y2 side resistor portion 28 is Iy2, since Iy1 × Ry1 = Iy2 × Ry2, the following relationship (Equation 9) holds. .
[0048]
[Equation 9]

[0049]
Further, the following relationship is established from (Equation 8) and (Equation 9).
[0050]
[Expression 10]

[0051]
According to this (Equation 10), it can be seen that the coordinate position of the finger 8 of the operator in the Y-axis direction can be detected by the ratio of the currents Iy1 and Iy2.
[0052]
Further, when E1 <E2, since the charge of the capacitor Cy is charged through the y1 and y2 side resistor portions 27 and 28 until the voltage E2 is reached, the directions of the currents Iy1 and Iy2 are reversed and −Iy1 and −Iy2 However, since (Equation 9) holds similarly, E1 <E2 may be satisfied.
[0053]
Then, the currents Iy1 and Iy2 are converted into voltage values by the I / V converters 18 and 19, respectively, further converted into digital values by the A / D converters 20 and 21, respectively, and input to the control unit 22 for control. The coordinate position of the operator's finger 8 in the Y-axis direction is detected by performing a comparison calculation on the unit 22.
[0054]
As described above, the coordinate position input apparatus according to the present invention can detect the coordinate position by performing the switching operation at least twice. Therefore, the detection time can be shortened and the selection units 12 and 13 can be small. It becomes.
[0055]
(Embodiment 2)
The second embodiment of the present invention has a configuration in which the belt-like portion 4A of the second resistor 4 of the coordinate position input device of the first embodiment is formed by a conductor instead of being formed by a resistor. It is what.
[0056]
When the plurality of strips 4A of the second resistor 4 are formed of conductors in this way, the delay in moving to the coupling part 4B of the charge of the capacitor Cy can be eliminated, so the detection time in the Y-axis direction is shortened. This is especially useful when doing so.
[0057]
【The invention's effect】
As described above, according to the present invention, it is possible to obtain a useful effect of realizing an excellent coordinate position input apparatus that can detect a coordinate position in a short time and that requires only a small configuration circuit.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a configuration of a coordinate position input device according to a first embodiment of the present invention. FIG. 2 is a plan view showing a configuration of the detection unit. FIG. 3 shows a configuration of a conventional coordinate position input device. Schematic diagram [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 1st resistor 2, 3 1st electrode 4 2nd resistor 4A 2nd strip | belt-shaped part 4B 2nd resistor connection part 6, 7 Second electrode 8 Operator's finger 9 Circuit ground 10, 11 Capacitance 12, 13 apparently formed First and second resistor selection units 14, 15 First and second resistor drive units 16, 17 Reference voltage 18, 19 I / V Conversion unit 20, 21 A / D conversion unit 22 Control unit 23 Control signal 24 of selection unit Control signal 25 of drive unit x1 side resistor portion 26 x2 side resistor portion 27 y1 side resistor portion 28 y2 side resistor portion

Claims (2)

A plurality of strip-shaped first resistors connected to a pair of strip-shaped first electrodes in which a plurality of strips are arranged at predetermined intervals and both ends thereof are opposed to each other, and the plurality of strip-shaped first resistors Of the pair of strip-shaped second electrodes arranged in parallel with the first resistor on the outer side of the first electrode, respectively, to a pair of strip-shaped connecting portions made of resistors that connect the ends of the pair of the second electrodes to the outside of the first electrode, respectively. A detection unit configured to input a coordinate position, and a selection for selecting the detection unit. The detection unit is configured by a band-shaped second resistor that is connected between the first resistor and is insulated between the first resistor. Unit, a drive unit that drives the detection unit, an I / V conversion unit that converts a current signal from the detection unit into a voltage signal, an A / D conversion unit that converts the voltage signal into a digital signal, and Coordinate position input consisting of a control unit that obtains coordinate positions from digital signals Apparatus. The coordinate position input device according to claim 1, wherein the band-shaped second resistor is formed of a conductor.

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