Reduced cost pointing stick circuit

    公开(公告)号:SG54464A1

    公开(公告)日:1998-11-16

    申请号:SG1997000346

    申请日:1997-02-15

    Applicant: IBM

    Abstract: A low-cost circuit processes, with high precision, the output signals of a pointing stick used for controlling a cursor on a computer display screen. A two-stage method of high precision moderate range analog-to-digital (A/D) conversion is combined with a known method of A/D conversion by sweeping a reference voltage across the range of the voltage to be measured at a known rate and noting the time of coincidence. Operational amplifiers of moderate quality are used in an open-loop mode, so that the operational amplifier inputs are high impedance. In order to get sufficient isolation from power supply noise and variations, the analog circuitry is isolated from the supply voltage while measurements are being made. To avoid interference from the digital switching transients of the microprocessor with the analog comparator switching time, the microprocessor is placed in idle mode, thereby removing its internal clock drive signals (and associated transients) from all of the microprocessor's internal circuitry except the timer which is being used to make the measurement. The resulting circuitry is capable of detecting a very small signal in noise spikes many times larger.

    A REMOTE SENSING DEVICE HAVING LOW POWER STANDBY MODE AND METHOD THEREOF

    公开(公告)号:HK1003075A1

    公开(公告)日:1998-10-09

    申请号:HK98102279

    申请日:1998-03-18

    Applicant: IBM

    Abstract: A Battery powered sensing device using an analog sensor has electronic circuitry that maintains sensitivity and calibration of the sensing device during quiescent periods with very little power drain. In one implementation, a joystick is provided with a sensitive analog sensor, such as strain gauges, connected to the shaft of the joystick. The strain gauges are connected in a bridge circuit across which a voltage is applied. Three operational amplifiers are connected to combinations of the strain gauges in the bridge circuit to generate X, Y and Z output voltages corresponding to the combined signals generated by the strain gauges. A microprocessor receives outputs from the sensitive analog sensor and generates a sample signal and performs a recalibration of sampled signals during periods of inactivity. The sampling interval for recalibration is increased in periods of extended inactivity, greatly reducing the current draw on the battery power supply and greatly reducing power requirements of the sensing device.

    6.
    发明专利
    未知

    公开(公告)号:BR9504034A

    公开(公告)日:1996-09-24

    申请号:BR9504034

    申请日:1995-09-15

    Applicant: IBM

    Abstract: A user interface apparatus and method for a computing or processing system employing a graphical user interface is presented. In order to provide a good user feel, and specifically to avoid a feeling of inertia or sluggishness in cursor motion as the user starts or stops movement, the apparatus and method provide a negative inertia transfer function. That is, the cursor movement signal produced by applying the input parameter to a transfer function in accordance with the invention is related to a sum of (i) the input parameter, and (ii) a signal related to the rate of change of the input parameter. This is preferably implemented as an additive high-pass transfer function. Preferred embodiments can employ analog circuitry or a digitally programmed transfer function algorithm. The input parameter to which the transfer function is applied can be a magnitude signal, such as that from a polar coordinate system, or separate components, such as x- and y-components from a rectangular coordinate system, can be treated separately.

    7.
    发明专利
    未知

    公开(公告)号:DE69629547T2

    公开(公告)日:2004-06-17

    申请号:DE69629547

    申请日:1996-12-23

    Applicant: IBM

    Abstract: A Battery powered sensing device using an analog sensor has electronic circuitry that maintains sensitivity and calibration of the sensing device during quiescent periods with very little power drain. In one implementation, a joystick is provided with a sensitive analog sensor, such as strain gauges, connected to the shaft of the joystick. The strain gauges are connected in a bridge circuit across which a voltage is applied. Three operational amplifiers are connected to combinations of the strain gauges in the bridge circuit to generate X, Y and Z output voltages corresponding to the combined signals generated by the strain gauges. A microprocessor receives outputs from the sensitive analog sensor and generates a sample signal and performs a recalibration of sampled signals during periods of inactivity. The sampling interval for recalibration is increased in periods of extended inactivity, greatly reducing the current draw on the battery power supply and greatly reducing power requirements of the sensing device.

    8.
    发明专利
    未知

    公开(公告)号:DE69629547D1

    公开(公告)日:2003-09-25

    申请号:DE69629547

    申请日:1996-12-23

    Applicant: IBM

    Abstract: A Battery powered sensing device using an analog sensor has electronic circuitry that maintains sensitivity and calibration of the sensing device during quiescent periods with very little power drain. In one implementation, a joystick is provided with a sensitive analog sensor, such as strain gauges, connected to the shaft of the joystick. The strain gauges are connected in a bridge circuit across which a voltage is applied. Three operational amplifiers are connected to combinations of the strain gauges in the bridge circuit to generate X, Y and Z output voltages corresponding to the combined signals generated by the strain gauges. A microprocessor receives outputs from the sensitive analog sensor and generates a sample signal and performs a recalibration of sampled signals during periods of inactivity. The sampling interval for recalibration is increased in periods of extended inactivity, greatly reducing the current draw on the battery power supply and greatly reducing power requirements of the sensing device.

    Low-power standby mode for a remote sensing device

    公开(公告)号:SG55264A1

    公开(公告)日:1998-12-21

    申请号:SG1997000025

    申请日:1997-01-08

    Applicant: IBM

    Abstract: A Battery powered sensing device using an analog sensor has electronic circuitry that maintains sensitivity and calibration of the sensing device during quiescent periods with very little power drain. In one implementation, a joystick is provided with a sensitive analog sensor, such as strain gauges, connected to the shaft of the joystick. The strain gauges are connected in a bridge circuit across which a voltage is applied. Three operational amplifiers are connected to combinations of the strain gauges in the bridge circuit to generate X, Y and Z output voltages corresponding to the combined signals generated by the strain gauges. A microprocessor receives outputs from the sensitive analog sensor and generates a sample signal and performs a recalibration of sampled signals during periods of inactivity. The sampling interval for recalibration is increased in periods of extended inactivity, greatly reducing the current draw on the battery power supply and greatly reducing power requirements of the sensing device.

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