Apparatus and methods for computer graphics

• US 3,906,197 A
• Filed: 03/05/1974
• Issued: 09/16/1975
• Est. Priority Date: 03/09/1973
• Status: Expired due to Term

• Current Assignee: Derrick John Grover
• Original Assignee: Derrick John Grover
• Inventors: Grover, Derrick John
• Primary Examiner(s): Botz, Eugene G.
• Application Number:
  US05/448,362
• Time in Patent Office: 560 Days
• Field of Search: 340/225,324A 235/151
• US Class Current: 345/180
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/04842 Selection of displayed objects or displayed text elements G06F3/0482 takes precedence
• CPC Class Codes: G06F 3/153 using cathode-ray tubes

Abstract

Apparatus for carrying out a spatial transform between information in two displays is described. Where one display is a graphical input tablet with an overlay forming graduations for the tablet, a point may be selected using a stylus and a corresponding point for example in a C.R.T. display may be intensity emphasized. The co-ordinates of the selected point are combined and the resulting number is compared with a number related to the position of a data item in a series of such items giving rise to the C.R.T. display. The positions of the data items in the series are arranged to give the required spatial transform when the number relating to position in the series equals the number formed by combining the co-ordinates of a selected point.

Claims

1. Apparatus for carrying out spatial transforms, including a store for data, display means, coupled to the store, for serially receiving items of data from the store and providing a display in accordance with the items received, each item being sufficient to allow the display means to provide a portion of the display, means for identifying the items of data by providing an identifying signal associated with each item, input means for generating signals representing the co-ordinates of selected points in a multi-dimensional region, comparison means for comparing the signals representing the coordinates with the identifying signals to indicate if a predetermined correlation exists, and means, coupled to the comparison means, for emphasising those portions of the display displayed in accordance with items of data having the predetermined correlation with current signals derived from co-ordinates.

2. Apparatus according to claim 1 wherein the input means includes means for providing a number of first and second digital signals, one first and second signal for first and second coordinates, respectively, of each selected point, and means for concatenating the first and second digital signals relating to each point to form the signals representing the coordinates of that point as a further digital signal in which the first and second digital signals appear one after another, and the means for identifying the items of data in operation provides identifying signals in the form of a pulse each time a portion of the display is provided, and includes a counter for counting the pulses, the comparison means being constructed to indicate the predetermined correlation whenever the contents of the counter equal one of said further digital signals.

3. Apparatus according to claim 2 wherein the means for concatenating the digital signals omits at least the least significant digit of each said first and second digital signal in forming each further digital signal.

4. Apparatus according to claim 2 wherein, in operation, the means for identifying items of data includes a clock pulse generator coupled to the store to cause one of the data items to be read out each time a clock pulse occurs, each clock pulse also being applied to the counter as the identifying signal for the data item which was read out on the occurrence of that clock pulse.

5. Apparatus according to claim 2 wherein each item of data stored includes a digital code marking the occurrence of that item, and the means for identifying items of data includes means for recognising that code and, on recognition, applying a pulse to the counter.

6. Apparatus according to claim 5 wherein the display means and means for identifying items of data are constructed to operate from data items made up from a variable number of multi-bits words in which the said code appears at a predetermined bit position, each data item containing information for a complete unit of the display.

7. Apparatus according to claim 1 for use where each item of data includes a digital code identifying that item, wherein the means for identifying items of data includes a holding store for holding the digital code for the data item determining the current display portion, the input means includes means for providing a number of first and second digital signals, one first and second signal for each coordinate of each selected point, and means for concatenating the first and second digital signals relating to each point to form the signal representing the coordinates of that point as a further digital signal in which the first and second digital signals for that point appear one after another, and the comparison means is constructed to indicate the predetermined correlation when the contents of the holding store equal a said further digital signal.

8. Apparatus according to claim 7 wherein the means for concatenating the digital signals omits at least the least significant digit of each first and second digital signal in forming each further digital signal.

9. Apparatus according to claim 1 wherein the input means includes a graphical input device.

10. Apparatus according to claim 9 wherein the graphical input device includes a planar area having means for designating portions of the area, and means for manually indicating by means of a pointer, the said selected points in the area.

11. Apparatus according to claim 9 wherein the graphical input device includes a cathode ray tube, means for causing the tube to provide a display designating areas of the tube face, and means for manually indicating the said selected points in the display.

12. ApparatUs according to claim 11 wherein the cathode ray tube is a storage tube, and the means for manually indicating selected points includes a continuously refreshed cursor and means for moving the cursor in accordance with manual controls.

13. Apparatus according to claim 2 wherein the display means includes a cathode ray tube, refresh means are provided for causing the store to pass groups of data items for a display repeatedly to the display means in order to constantly refresh the display provided by the cathode ray tube, and means are provided for resetting the counter each time a group of data items has been passed to the display means.

14. Apparatus according to claim 2 wherein the display means includes a cathode ray tube, the store includes a plurality of stages each capable of storing information and the store, in operation, circulates data items continuously through its stages and, means are provided for resetting the counter each time the data items in the store have circulated through the stages.

15. Apparatus according to claim 2 wherein the data items are read from the store once only in forming each display, the means for identifying the items of data provides each identifying signal immediately before the associated item is displayed, in order to allow a portion to be emphasised when it is displayed if the predetermined correlation exists.

16. Apparatus according to claim 2 wherein the means for emphasising portions does so by brightening the emphasised portion in relation to the rest of the display.

17. Apparatus for carrying out spatial transforms, including a first store for data, first multi-dimensional display means, coupled to the store, for receiving items of data from the store and providing a first display in accordance with the items received, at least one further multi-dimensional display means for providing a further display which is different from the first display, but is related thereto, selection means for selecting one portion of one of the displays, correlation means for determining which portion if any, of at least one of the other displays has a predetermined correlation with a portion of the said one display selected using the selection means, and means, coupled to the correlation means, for emphasising any portion of the said one other display which has the predetermined correlation with a selected portion of the said one display.

18. Apparatus according to claim 17 wherein the selection means is constructed to select one portion of the first display, the correlation means includes means, coupled to the selection means for holding a signal identifying the item of data giving rise to the selected portion, and the emphasis means is coupled to the correlation means to emphasise a portion of at least one of the further displays determined by the signal held.

19. Apparatus according to claim 17 including a further store for storing items of data from which the further display is formed wherein the correlation means includes a clock pulse generator coupled to the first store and the further store to provide clock pulses each of which causes the first and further stores to each pass an item data to the first and further display means, respectively, and the emphasis means is constructed to emphasise that portion of one display resulting from the item of data read from one store at the same time as the item of data giving rise to the said selected portion of another display.

20. Apparatus according to claim 17 including a further store for storing items of data from which the further display is formed, and first and second means for identifying data items from the first and further stores, respectively, by generating first and second series of identifying signals, each identifying signals being associated with one data item, wherein the selection means is constructed to hold a selected identifying signal from one series corresponding to a selected portion of one display, the correlation means compares the selected identifying signal from the one series and the current identifying signal from the other series, and the emphasis means is constructed to emphasise that portion of the other display display resulting from that data item which is associated with an identifying signal which has the predetermined correlation with the selected identifying signal.

21. A method for carrying out spatial transforms, including forming a display from items of data received serially, each item being sufficient to allow a portion of the display to be formed, identifying each item of data, generating signals representing the co-ordinates of a point in a multi-dimensional region, comparing the identity of each item with the co-ordinate signals, and emphasising those portions of the display resulting from items of data which have a predetermined correlation with the co-ordinate signals for the said point.