Abstract: An electromagnetic detector having plural loop coils arranged in parallel with one another in a position detecting direction determines a position coordinate value designated by a position indicator having at least a coil. One loop coil in each of plural groups is selected simultaneously from plural loop coils of the group so not less than a predetermined number of the relative positions of these selected loop coils are not the same or are a symmetric in each group and over a plurality of groups. A loop coil on which the position indicator is positioned is determined in response to a signal amplitude pattern obtained by the loop coil selection. This makes it unnecessary to select all loop coils at the time of starting a position detecting operation, to reduce the time required to determine the coordinate value.

Abstract: The present invention provides a sensing unit for a position detecting apparatus permitting freer setting of a reading efficiency and having a thinner appearance and its manufacturing method for realizing simple manufacturing, high yield, and low cost.According to the present invention, two plies of conductor patterns 22 and 23 are produced on one side 21a of an insulating substrate 21 to form a plurality of sense wires, a shielding plate 28 is adhered to other side of the insulating substrate 21, then the insulating substrate 21 is died together with the shielding plate 28. This obviates through holes for which drilling the insulating substrate is required, and diminishes the difference between the distances of the two plies of conductor patterns 22 and 23 from a position indicator. Furthermore, a spacer for separating conductor patterns from a shield becomes unnecessary.

Abstract: A determination is made as to which one of plural objects is proximate a region having a coil therein. Each object includes a tuned circuit having a different resonant frequency. AC energy at the different resonant frequencies is supplied to the coil. The tuned circuit on the particular object in the region having substantially the same resonant frequency as the AC energy supplied to the coil causes a change in the current flowing in the coil at the same resonant frequency. The change in the current flowing in the coil at the same resonant frequency is sensed. In response to the current change at the same resonant frequency the particular object having the tuned circuit with the same resonant frequency as the frequency of the applied AC energy is indicated with a phase detector arrangement responsive to the changed current flowing in the coil at the same resonant frequency and a reference wave at the same resonant frequency.

Abstract: A coordinate input system has a tablet composed of an X-direction loop coil assembly and a Y-direction loop coil assembly, and an input pen having a tuning circuit the tuning frequency of which is variable about a predetermined frequency. The system has a coordinate detecting function for detecting the X- and Y-coordinate values of position input by the input pen, and a phase detecting function for detecting the change in the tuning frequency of the tuning circuit as a change in the phase with respect to the phase of the predetermined tuning frequency. Information concerning the detected coordinate point, e.g., spread of the coordinate point proportional to the pressure at which the pen is pressed onto the tablet, is computed in accordance with the amount of change in the phase detected by the phase detecting function.

Abstract: The position of an implement is determined relative to a tablet including a tuned circuit with a resonant frequency including coils arranged in two coordinate directions. Coils of the tablet are sequentially excited with AC energy having approximately the same frequency as the resonant frequency. The tuned circuit interacts with the AC energy to change the AC current flowing in coils of the tablet as a function of the implement position so the greatest changes in the AC current are in coils of the tablet closest to the implement. Detected values of changes in current as a function of coil position are interpolated to indicate the implement position.

Abstract: A characteristic and the position of an implement with a tuned circuit having one of plural resonant frequencies are determined. AC energy at the plural different resonant frequencies is supplied to a two-coordinate direction coil arrangement of a position sensing tablet. The tuned circuit changes the current flowing in the coil arrangement at the implement resonant frequency. The current change is used to signal the implement position and characteristic. The implement may be an eraser for supplying a signal to an electronic display and for removing a mark from a surface of a visual display overlaying the tablet of the eraser. A housing includes a surface for erasing the marking and two tuned circuits each having a reactance positioned close to opposite edges of the erasing surface. Two switches, when activated, cause the tuned circuits to have different resonant frequencies. The switches are respectively activated when opposite eraser edges are being pushed against the display surface.

Abstract: The position on a surface of an implement including a tuned circuit with a predetermined resonant frequency is determined and displayed by an apparatus having a housing including the surface. A tablet in the housing includes coils arranged in two coordinate directions parallel to the surface. The coils are excited with AC energy having approximately the same frequency as the resonant frequency. The tuned circuit interacts with the AC energy to change the AC current flowing in the coils as a function of the implement on the tablet. An electronic two-coordinate direction display in the housing configured as a plate is superposed with and lies in a plane parallel to the tablet and the surface. The display responds to the change in AC current resulting from the interaction between the AC energy and the tuned circuit to indicate the position of the implement on the surface.

Abstract: A position detecting apparatus for detecting a position pointed by an input pen which comprises: a position detection section constituted by first and second coil groups each composed of a plurality of loop coils; an input pen having a tuning circuit having a predetermined frequency as a tuning frequency; selector means for successively selecting the loop coils of the first and second coil groups of the position detection section one by one; signal generation means for supplying an A.C. signal of the predetermined frequency to the loop coils; signal detection means for detecting the A.C. signal of the predetermined frequency from the loop coils; and controller means for identifying the position pointed by the position pointer on the basis of the A.C. signal detected by the signal detection means from among the loop coils of the first and second coil groups, whereby the position pointed by the input pen can be detected on the basis of the induced voltages obtained in the first and second coil groups.

Abstract: A system for detecting the types and statuses of position designating devices is incorporated in a coordinates input apparatus having a tablet constituting a coordinates input section, a plurality of position designating devices of different types, and a position detecting circuit for driving the tablet and detecting positions at which coordinates are input by the position designating devices. The system has an antenna coil disposed around a coordinates input range of the tablet, and a tuning circuit disposed in each of the position designating devices for transmitting radio waves in response to an external signal at an individual frequency determined in accordance with the type of the corresponding position designating device. An AC signal of predetermined frequencies is applied to the antenna coil so that it transmits radio waves.

Abstract: A coordinate input device with a display includes a tablet composed of two position detecting units each formed by alternately arranged exciting and detecting lines parallel to each other on a magnetic member in the form of a sheet. These units are overlaid one upon the other so that exciting and detecting lines of one unit extend orthogonally with respect to those of the other. A planar display is overlaid on the tablet. The device further includes a position designating magnetic generator which locally applies a magnetic bias to the magnetic members of the tablet. The exciting lines of the tablet are supplied with an alternating current of a predetermined cycle by a driving current source. A position detecting circuit detects the coordinate values of a position designated by the position designating magnetic generator from the induced voltages respectively generated from the detecting lines of the tablet. The display is driven by a display control circuit.

Abstract: A position detecting apparatus for detecting a position pointed by a pointer on a system such as a digitizer has the following parts: a position detection section having a plurality of loop coils arrayed in a side-by-side fashion in the direction of position detection; a selection circuit for successively selecting the loop coils one-by-one; a transmission circuit for generating an A.C. signal of a predetermined frequency to be delivered to the selected loop coil; a receiving circuit adapted to detect an induced voltage of a frequency substantially the same as that of the A.C. signal from among various voltages induced in the selected loop coil; a connection switching circuit for connecting the selected loop coil alternately to the transmission circuit and the receiving circuit; a position pointer having a tuning circuit including a coil and a capacitor and adapted to resonate with an electric wave produced by the loop coil which is supplied with the A.C.

Abstract: A coordinate input device with a display includes a position detecting tablet having a plurality of X-direction magnetostrictive transmission mediums and a plurality of Y-direction magnetostrictive transmission mediums superposed orthogonally, a first coil wound around one end of the array of magnetostrictive transmission mediums, and a second coil wound over substantially the entire lengths of the magnetostrictive transmission mediums. A position indicated on the tablet by a position indicating magnetism generator is detected by measuring the length of time between the moment at which a pulse current is applied to one of the first and second coils and the moment at which the voltage induced in the other of the first and second coils by a magnetostrictive vibration wave exceeds a threshold value owing to the sudden increase of voltage observed when the wave passes the indicated position.

Abstract: Disclosed is a coordinates input system having a tablet constituting a coordinates input portion, a position designating device such as a stylus pen, and a position detection circuit adapted to drive said tablet and detect a position at which coordinates are input by said position designating device. The system comprises: an antenna coil disposed around a coordinates input range of said tablet; and a tuning circuit disposed in said position designating device and including a coil and a capacitor, wherein radio waves are generated by said antenna coil by application of an AC signal of a predetermined frequency thereto, and the status of said tuning circuit is discriminated by a signal of said antenna coil at the time when the transmission of said radio waves is suspended, thereby detecting the status of said position designating device.

Abstract: A position detecting device includes a tablet which has a magnetic sheet and two conductor sheets. The magnetic sheet is formed by weaving a group of warp elements (or weft elements) having multiple insulating fibers and a plurality of relatively long magnetic elements disposed among the fibers at predetermined regular spacings and a group of weft elements (or warp elements) having multiple insulating fibers into a plain weave fabric, which is hardened into a sheet-like configuration. Each of the conductor sheets has a plurality of linear conductor elements extending substantially parallel to each other. The two conductor sheets are respectively overlaid on the upper and lower sides of the magnetic sheet so that the conductor elements and the magnetic elements extend orthogonally with respect to each other. The corresponding conductor elements of the upper and lower conductor sheets are connected to from alternate exciting and detecting lines.

Abstract: A coordinate input device with display includes a tablet having a plurality of parallel X-direction magnetostrictive transmission mediums, a plurality of parallel Y-direction magnetostrictive transmission mediums superposed on, and substantially orthogonal to the X-direction mediums thereto, and first and second coils wound around the magnetostrictive transmission mediums. The device further includes a plurality of biasing magnetic means for applying a biasing magnetic field to portions of the magnetostrictive transmission mediums surrounded by the first and second coils, and a tabular display superposed on the tablet and having a display area substantially equal to the position detection area on the tablet. A magnetic pen is used to cause a local increase of electro-mechanical coupling coefficient in the magnetostrictive transmission mediums in the tablet.

Abstract: A position detecting device includes a magnetic member composite which is integrally composed of a pair of insulating substrates with a plurality of long magnetic members sandwiched therebetween and arranged substantially parallel to each other and two conductive member composites, each of which is composed of a plurality of conductive members arranged substantially parallel to each other.

Abstract: A position detecting device includes a tablet which has a magnetic sheet and two conductor sheets. The magnetic sheet is formed by weaving a group of warp elements (or weft elements) having multiple insulating fibers and a plurality of relatively long magnetic elements disposed among the fibers at predetermined regular spacings and a group of weft elements (or warp elements) having multiple insulating fibers into a plain weave fabric, which is hardened into a sheet-like configuration. Each of the conductor sheets has a plurality of linear conductor elements extending substantially parallel to each other. The two conductor sheets are respectively overlaid on the upper and lower sides of the magnetic sheet so that the conductor elements and the magnetic elements extend orthogonally with respect to each other. The corresponding conductor elements of the upper and lower conductor sheets are connected to from alternate exciting and detecting lines.

Abstract: A system for detecting the types and statuses of position designating devices is incorporated in a coordinates input apparatus having a tablet constituting a coordinates input section, a plurality of position designating devices of different types, and a position detecting circuit for driving the tablet and detecting positions at which coordinates are input by the position designating devices. The system has an antenna coil disposed around a coordinates input range of the tablet, and a tuning circuit disposed in each of the position designating devices for transmitting radio waves in response to an external signal at an individual frequency determined in accordance with the type of the corresponding position designating device. An AC signal of predetermined frequencies is applied to the antenna coil so that it transmits radio waves.

Abstract: Disclosed is a coordinates input system having a tablet constituting a coordinates input portion, a position designating device such as a stylus pen, and a position detection circuit adapted to drive said tablet and detect a position at which coordinates are input by said position designating device. The system comprises: an antenna coil disposed around a coordinates input range of said tablet; and a tuning circuit disposed in said position designating device and including a coil and a capacitor, wherein radio waves are generated by said antenna coil by application of an AC signal of a predetermined frequency thereto, and the status of said tuning circuit is discriminated by a signal of said antenna coil at the time when the transmission of said radio waves is suspended, thereby detecting the status of said position designating device.

Abstract: A characteristic and the position of an implement with a tuned circuit having one of plural resonant frequencies are determined. AC energy at the plural different resonant frequencies is supplied to a two-coordinate direction coil arrangement of a position sensing tablet. The tuned circuit changes the current flowing in the coil arrangement at the implement resonant frequency. The current change is used to signal the implement position and characteristic. The implement may be an eraser for supplying a signal to an electronic display and for removing a mark from a surface of a visual display overlaying the tablet of the eraser. A housing includes a surface for erasing the marking and two tuned circuits each having a reactance positioned close to opposite edges of the erasing surface. Two switches, when activated, cause the tuned circuits to have different resonant frequencies. The switches are respectively activated when opposite eraser edges are being pushed against the display surface.