Touch controlled zoom of waveform displays

• US 4,755,811 A
• Filed: 03/24/1987
• Issued: 07/05/1988
• Est. Priority Date: 03/24/1987
• Status: Expired due to Term

• Current Assignee: Tektronix Incorporated (Fortive Corp.)
• Original Assignee: Tektronix Incorporated (Fortive Corp.)
• Inventors: Craig, Donald, Slavin, Keith R.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/030,758
• Time in Patent Office: 469 Days
• Field of Search: 340/709, 340/731, 340/722, 340/721, 340/734, 324/121 R
• US Class Current: 345/668
• CPC Class Codes: G01R 13/20 Cathode-ray oscilloscopes
• CPC Class Codes: G06F 3/033 Pointing devices displaced or positioned by the user , e.g. mice, trackballs, pens or joysticks; Accessories therefor digitisers characterised by the transducing means G06F3/041

Abstract

Touch controlled zoom of a waveform display uses a touch screen for the display surface. Function buttons for moving or expanding the waveform display and for determining the axis of such movement or expansion operate in conjunction with a rotary encoder. Expansion, or zoom, is accomplished by contacting the screen overlying a point on the waveform about which zoom is desired. Such contact or activation of the expand function button results in movement of the rotary encoder providing a gain parameter to a zoom function. The zoom function operates on the waveform display in an exponential manner as a function of the gain parameter to expand or contract the waveform display about the zoom point according to the direction of rotation of the rotary encoder.

Claims

1. An apparatus for controlling zoom of a displayed waveform comprising:

means for indicating a point on the displayed waveform about which zoom is desired; and

means for zooming the displayed waveform about the indicated point so that the indicated point remains stationary.

2. An apparatus as recited in claim 1 wherein the indicating means comprises:

a display surface overlying the displayed waveform; and

means for converting a default position with respect to the display surface into a waveform point on the displayed waveform underlying the default position, the waveform point being the indicated point.

3. An apparatus as recited in claim 2 wherein the indicating means further comprises means for determining the default position by contacting the display surface at a surface point overlying the point about which zoom is desired.

4. An apparatus as recited in claim 1 wherein the zooming means comprises:

means for entering a zoom function; and

a rotary encoder, rotation of which results in changing a gain parameter which is used by the zoom function for zooming the displayed waveform about the indicated point.

5. An apparatus as recited in claim 4 wherein the entering means comprises:

a display surface overlying the displayed waveform; and

means for interpreting contact of the display surface as a command for entering the zoom function.

6. An apparatus as recited in claim 1 further comprising means for determining an axis along which zoom is desired.