International Business Machines Corporation

Valerie McLaren Findlay

Andrew Ramsay Knox

Andrew J Morrish

Graham Luck

Terence K Gibbs

David J Eagle

A touch-sensitive display apparatus is disclosed, which includes a display screen. A display drive means is connected to the display screen for generating an image on the display screen in response to an input video signal. A display processor is connected to the display drive means for generating, in response to one or more image control signals, at least one drive control signal for configuring the display drive means to move the displayed image relative to the display screen. Touch sensing means generates a touch input signal in response to a tactile stimulus of the display screen. The touch input signal is indicative of the location of the tactile stimulus on the touch screen. A touch processor is connected to the touch sensing means for converting, in dependence on calibration data stored in a touch memory, the touch input signal into coordinates defining the location of the tactile stimulus on the display screen relative to features in the image displayed on the display screen. The display processor includes means for communicating correction data indicative of movement of the displayed image relative to the display screen to the touch processor. Touch processor comprises means for automatically adjusting the calibration data stored in the touch memory to re-align the coordinates generated by the touch processor to features in the displayed image in response to the correction data received from the display processor.

Touch-sensitive display apparatus

An elapsed time recording device includes a counter (130) for incrementally advancing a count value from an initial value towards and beyond a threshold in response to successive clock pulses of a clock signal. Control logic (140) enables the counter (130) to incrementally advance the count value in response to a first input (pin 3) and a second input (pin 1) being at or near a first voltage level, and holds the count value in response to the first input (pin 3) being at or near a second voltage level and the second input (pin 1) being at or near the first voltage level. Setting logic (210) sets the count value to a value beyond the threshold in response to the first input (pin 3) and the second input (pin 1) being at or near the second voltage level when the count value is between the initial value and the threshold. Because the device consists essentially of electronic circuit elements, it can be implemented in the form of an application specific integrated circuit package suitable for high volume manufacture at relatively low cost. The device is therefore favorable for use in mass produced electrical appliances. Because the count value is immediately advanced beyond the threshold in response to removal of the second input voltage, advance of the count value towards the threshold cannot be prevented or delayed by tampering with pin connections of the device.

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Glasgow, United Kingdom

Valerie McLaren Findlay