VISUAL DISPLAY APPARATUS

Abstract: A visual display apparatus is disclosed which allows annotations of a piece of displayed text to be shown in a visually differentiable mode from that in which the text is displayed. This allows for easy discrimination between the original text and subsequent annotations.

Description: VISUAL DISPLAY APPARATUS FTPI .D OF THE INVENTION This invention relates to a visual display apparatus and in particular to a visual display apparatus which can display images on a display means in at least two visually differentiable display modes. DESCRIPTION OF THE PRIOR ART The term display mode refers to the manner in which the di.splay means is controlled to provide the image. When one is using a display means such as a CRT (cathode ray tube) which can only display monochrome images, e.g. black and white, then the display mode will be either monochrome mode, or dither pattern mode when the illusion of mid-tones is needed. Images in each mode will be displayed in monochrome or as a dither pattern, respectively. When one has a grey .scale monitor, the display mode could be one of the members of that grey scale, e.g. black, in which case images will be displayed in black. Similarly with a full colour monitor, if the display mode is red, then images will be displayed in red. When documents are produced on a word processor by a typist, they not infrequently require revision by the author. Commonly this is achieved by printing out a draft of the letter and getting the author to annotate it in manuscript form. In more sophisticated computing environments, the author may have his or her own computer connected to that of the typist, allowing on screen review of the draft and keyboard amendments to be made directly by the author. In some such systems, such as the Wang (Regd. T.M.) Freestyle the author will have in addition a graphics tablet enabling appropriate manuscript annotations to be made for the guidance of the typist or indeed anyone else who might read the document In widely networked environments, it may be useful to be able to comment on documents produced by others by annotating them using the graphics tablet. One of the problems inherent to such sophisticated prior art systems is that the annotations displayed on the display unit may not be readily and easily distinguishable from the underlying displayed material which is annotated/This may be inconvenient and confusing to the reader. Similarly, allowing different annotations to be clearly differentiable from one another has not been directly provided for. OBJECTS OF THE INVENTION It is an object of the present invention to provide a visual display apparatus which allows annotations to displayed information to be clearly and easily differentiated from that information. STATEMENT OF THE INVENTION In accordance with the present invention, a visual display apparatus comprises a visual display means, and a controller for controlling the visual display means to display an image using at least two visually differentiable display modes, and is characterised in that when a first and second image are displayed together on the visual display means, the second image comprising substantially annotations of the first image, the controller provides for each image to be in a different mode. It will be appreciated that this technique fully meets the requisite objects of this invention and overcomes the prior art limitations. Conveniently, if the first image is displayed in monochrome mode, then the second image can be in a dither pattern mode. Similarly, if the first image is displayed in a given grey mode, i.e. appears as a given grey in a grey scale, then the .second image can be in a different grey mode, i.e. appears as a different grey. Still further, if the first image is displayed in a given colour mode, then the second image can be displayed in a different colour mode, i.e. the two images appear in different colours. In a particular aspect of the invention, a visual display apparatus as described above further comprises a data input means overlaying, underlying or integral with the visual display means and cooperating with a manually movable stylus member whereby the stylus is operable to allow graphical data input by a user . Preferably, in such a visual display apparatus the said second image is generated by the controller in dependence upon the graphical data input In a still further aspect of the invention, there is provided a computing apparatus comprising a visual display apparatus as hereinbefore described. BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention will now be further described with reference to the accompanying drawings in which:- Figure 1 is a plan view of a visual display apparatus in accordance with the present invention; Figure 2 is a schematic block diagram illustrating the major components of such a visual display apparatus ; Figure 3 provides a typical depiction of what might be displayed by such an apparatus. ΠFTAΠ F.D DESCRIPTION Referring now to Figure 1, a display means 2, preferably comprising a LCD type display, is shown forming part of a visual display apparatus indicated generally at 1. The input means for the apparatus comprises a translucent transducer pad 3 overlaying the display 2, together with a stylus 4. The pad 3 is an Indium Tin Oxide (ITO) device which is well known in this art . It is operable to supply a signal indicative of the position at which the stylus 4 touches the pad 3 and allows the user to easily and naturally input graphical information for storage and subsequent, although nearly immediate, display by the apparatus. It will be appreciated that a variety of components, e.g. a power supply, is necessary for the functioning of the apparatus and will have to be present in the apparatus but these are not expressly detailed here in the interests of brevity and clarity. Referring now to Figure 2, the transducer ITO pad 3 is shown schematically overlaying the LCD type display 2. The stylus 4 is touching the pad 3 and electrical signals indicative of the position (X Y Co-ordinates) at which it SUBSTITUT SHEET contacts the pad 3 are supplied from the stylus 4 to an A to D converter 11 feeding a data path or system bus 10. As an alternative to the ITO approach, reference may be made to an inductive system developed byWacom Co. Ltd (not shown). In such a system, an LCD type display has superposed on it an array of successively energisable induction loops. A stylus is provided which incorporates a tuning circuit which resonates at a frequency specific to a given loop, thereby identifying the position of the stylus with respect to the display. Further reference may be made to US-4848496-A. Returning to Figure 2, a CPU 12 is connected for bi-directional data flow to the bus 10, as is a RAM 17. A ROM 18 is also connected to bus 10, being programmed with the operating system for the apparatus. CPU 12 provides all control signals via bus 10. RAM 17 stores the user input (i.e. the annotations) in locations dependent on and associated with the image which is annotated. RAM 17 may be an EEPROM or magnetic bubble memory. CPU 12 may be a microprocessor such as the 8088 manufactured by Intel Corporation. In addition there is provided a parallel data interface 19 connected to bus 10 for sending and receiving information. A display driver 14 is connected to bus 10 and drives the display 2. The display driver 14 can drive the display 2 in any of the available modes. If the present embodiment uses a monochrome screen then the available modes are monochrome and a variety of dither pattern modes. The user can select what image or parts of an image are displayed in which mode. There are a variety of ways of allowing the user to communicate this choice to the apparatus. Commonly, the most convenient would be by arranging for a drop down menu to be available from which the user could make a choice of what mode was selected. The image to be displayed in that mode may be selected by a variety of conventional techniques, the most common being to drag the cursor over the required portions. Conveniently, the user may make a choice of which mode to use prior to inputting any information, such as annotations. In use, the user may, for example, have supplied to his or her apparatus a draft letter for approval. This would be sent via the parallel interface 19 from a typist and would be stored in RAM 17 and cause an appropriate control signal to issue from the driver 14 to result in an appropriate image 20 to be displayed on the display 2. The user may have set up the apparatus so that unannotated information such as draft text is displayed as black type 20 on a white background. The user then selects, from a drop down menu, the mode in which his or her annotations 21 will appear and be stored at RAM 17 . For example, a dither pattern, emulating a light grey, is chosen in the example illustrated in Figure 3. The user then inputs the information using the stylus. The manuscript annotations 21 appear displayed by the display 2 immediately underneath the points on the ITO pad 3 they would have appeared on were the ITO a piece of paper and the stylus 4 a pen. Those annotations 21 appear as light grey manuscript amendments apparently on top of the black text 20 they are associated with. The composite document comprising original text and annotations is stored in RAM 17 and a copy may be sent via parallel interface 19 to the typist for the necessary amendments to be made.

Claims: CLAIMS 1. Visual display apparatus comprising a visual display means, and a controller for controlling the visual display means to display an image using at least two visually differentiable display modes, characterised in that when a first and second image are displayed together on the visual display means, the second image comprising substantially annotations of the first image, the controller provides for each image to be in a different mode. 2. Visual display apparatus as claimed in Claim 1 wherein the first display mode is monochrome mode and the second display mode is a dither pattern mode. 3. Visual display apparatus as claimed in Claim 1 wherein the first display mode is a first grey and the second display mode is a different grey. 4. Visual display apparatus as claimed in Claim 3 wherein either grey approximates to black. 5. Visual display apparatus as claimed in Claim 1 wherein a first display mode is a first colour and the second display mode is a different colour. 6. Visual display apparatus as claimed in any preceding Claim further comprising a data input means overlaying, underlying or integral with the visual display means and cooperating with a manually movable stylus member whereby the stylus is operable to allow graphical data input by a user. 7. Visual display apparatus as claimed in Claim 6 wherein the said second image is generated by the controller in dependence upon the graphical data input 8. Computing apparatus comprising a visual display apparatus as claimed in any preceding Claim. SUBSTITUTE SHEET

Inventors: RANDALL STEPHEN, RANDALL, STEPHEN
Applicants: EDEN DESIGN GROUP LIMITED
Application year: 1990
Main classification: G09G1
IPC codes: G06F3, G06F17, G09G1, G09G5