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Title:
DISPLAYING AN IMAGE
Document Type and Number:
WIPO Patent Application WO/2010/020961
Kind Code:
A1
Abstract:
The invention relates to a method, a display apparatus (100) and an electronic device (800) for displaying an image. The display apparatus (100) comprises a controller (110) and a touch screen display (105). The touch screen display (105) is constructed for displaying an image and for receiving a touch event from a user. The controller (110) is constructed for generating the image. The image comprises a first area (101) for displaying a first sub image and comprises a second area (102) for receiving the touch event indicating a change of an aspect of the first sub image on the touch screen display (105). Furthermore the image comprises a third area (103) for displaying a selectable item and comprises a fourth area (104). The fourth area (104) is adjoining both the second (102) and third area (103) and at least partially arranged in between the second (102) and third area (103). The controller (110) is further constructed for not changing an aspect of the first sub image if the touch event occurs within the third area (103) or the fourth area (104) and for selecting the selectable item if the touch event starts within the fourth area (104) and ends within the third area (103).

Inventors:
HOLLEMANS, Gerrit (Building 44, AE Eindhoven, NL-5656, NL)
Application Number:
IB2009/053683
Publication Date:
February 25, 2010
Filing Date:
August 21, 2009
Export Citation:
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Assignee:
KONINKLIJKE PHILIPS ELECTRONICS N.V. (Groenewoudseweg 1, BA Eindhoven, NL-5621, NL)
HOLLEMANS, Gerrit (Building 44, AE Eindhoven, NL-5656, NL)
International Classes:
G06F3/048; G06F3/0485; G06F3/0488
Foreign References:
US20080168404A1
US20050075168A1
US20060117108A1
Attorney, Agent or Firm:
KROEZE, John et al. (High Tech Campus, Building 44, AE Eindhoven, NL-5656, NL)
Download PDF:
Claims:
CLAIMS:

1. A display apparatus (100, 200 and 400) comprising a touch screen display (105,405) for displaying an image and for receiving a touch event from a user, and a controller (110) constructed for (i) generating the image comprising a first area (101,401) for displaying a first sub image, a second area (102) for receiving the touch event indicating a change of an aspect of the first sub image on the touch screen display (105), a third area (103,403) for displaying a selectable item and a fourth area (104,404) adjoining both the second area (102,402) and the third area (103,403) and at least partially arranged in between the second area (102,402) and the third area ( 103 ,403),

(ii) not changing the aspect of the first sub image if the touch event occurs within the third area (103,403) or the fourth area (104,404), and

(iii) selecting the selectable item if the touch event starts within the fourth area (104,404) and ends within the third area (103,403).

2. A display apparatus (100, 200 and 400) according to claim 1, wherein the change of an aspect of the first sub image is any of the group of: translation of the first sub image, rotation of the first sub image, reduction or increase of the size of the first sub image, or changing any of the attributes intensity, colour balance, contrast, saturation or hue of the first sub image.

3. A display apparatus (100, 200 and 400) according to claim 1, wherein the touch event comprises a move on the touch screen display (105) and wherein the controller

(110) is constructed for selecting the selectable item if the touch event starts in the fourth area (104), moves into the third area (103) and ends in the third area (103) and wherein the third (103) and fourth area (104) are constructed such that the move from the fourth area (104) to the third area (103) is entirely within the fourth area (104) and the third area (103).

4. A display apparatus (100, 200 and 400) according to claim 1, wherein the received change of the aspect of the first sub image in the second area (102) indicates a scrolling of the first sub image in the first area (101), and wherein the controller (110) is constructed for not scrolling the first sub image in the first area (101) if the touch event occurs within the third area (103) or fourth area (104).

5. A display apparatus (100,200 and 400) according to claim 1, wherein the first area (101) at least partly overlaps the second area (102).

6. A display apparatus (400) according to claim 4, wherein first area (401) comprises the third area (403).

7. A display apparatus (400) according to claim 5, wherein the first area (401) coincides with the second area (402) and wherein the third area (403) is surrounded by the fourth area (404).

8. A display apparatus (400) according to claim 1, wherein the controller (110) is constructed for generating a second sub image that displays feedback (406) on the touch screen display (105) at the location on the touch screen display (105) where the touch event is received.

9. A display apparatus (400) according to claim 1, wherein the controller (110) is further constructed for generating a second sub image that displays feedback (500) on the touch screen display (405) related to the fourth area (404).

10. A display apparatus (400) according to claim 1, wherein the controller (110) is further constructed for generating a second sub image that displays feedback (600) on the touch screen display (405) if the touch event starts in the fourth area (404).

11. A display apparatus (400) according to claim 1, wherein the controller (110) is further constructed for generating a second sub image that displays feedback (700) on the touch screen display (405) if the touch event is inside the third area (403).

12. A display apparatus (100) according to claim 1, wherein the dimensions of the fourth area (804) are such that the effects of parallax due to a pre-defined viewing angle (φ) of the user and due to a thickness of a transparent plate (901) in front of the touch screen display (900) are at least partly compensated.

13. A display apparatus (100) according to claim 1, wherein the third area (806) has a larger dimension in a first direction (808) than in a second direction (809), the first direction (808) being different from the second direction (809), wherein the third area (806) is completely surrounded by the fourth area (807) and wherein the dimensions of the fourth area (807) are such that the distance from the border (810) of the fourth area (807) to the border of third area (806) is larger in the second direction (809) than in the first direction (808).

14. An electronic device (800) comprising the display apparatus (100) according to claim 1.

15. A method of displaying an image comprising the steps of: generating (1001) an image comprising a first area (101) for displaying a first sub image, a second area (102) for receiving a touch event indicating a change of an aspect of the first sub image, a third area (103) for displaying a selectable item and a fourth area (104), which adjoins both the second area (102) and the third area (103) and which is at least partially arranged in between the second (102) and third area (103), displaying (1002) the image on a touch screen display, (105) receiving (1003) the touch event from a user on the touch screen display (105), - determining (1004) whether the touch event is received within the second area

(102) and indicates the change of the aspect of the first sub image, changing (1005) the aspect of the first sub image on the touch screen display (105) if the touch event is received within the second area (102) and indicates the change of the aspect of the first sub image, - determining (1006) whether the touch event occurs in the third area (103) or the fourth area (104), not changing (1007) the aspect of the first sub image if the touch event occurs in the third area (103) or the fourth area (104), determining (1008) whether the touch event starts within the fourth area (104) and ends within the third area (103), and selecting (1009) the selectable item if the touch event starts within the fourth area (104) and ends within the third area (103).

Description:
Displaying an image

FIELD OF THE INVENTION

The invention relates to a display apparatus comprising a touch screen display and a controller, to an electronic device comprising the display apparatus, and to a method of displaying an image.

BACKGROUND OF THE INVENTION

Published patent application WO2007/0150830A1 discloses a portable electronic device comprising a touch screen. The touch screen displays a scrollable list with selectable items. A user is able to scroll through the list by applying scroll gestures in an area of the touch screen. The scroll gesture comprises a movement of a touching object over the touch screen. The items can be selected by touching the touch screen on the displayed selectable item. However, it is difficult to select the items in the scrollable list. Due to parallax and inaccuracy in the movements of the user, the user often touches the touch screen outside the selectable item or selects the wrong item.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a display apparatus which provides a solution to compensate for inaccurate touches of the touch screen. The inaccurate touches may be the result of the effects of parallax and inaccuracies of the movements of the user. A first aspect of the invention provides a display apparatus as claimed in claim

1. A second aspect of the invention provides an electronic device as claimed in claim 14. A third aspect of the invention provides a method as claimed in claim 15. Advantageous embodiments are defined in the dependent claims.

A display apparatus in accordance with the first aspect of the invention comprises a controller and a touch screen display. The touch screen display receives a touch event from a user and displays an image. The image is generated by the controller and comprises a first area, a second area, a third area and a fourth area. The first area displays a first sub image. The second area is for receiving the touch event indicating a change of an aspect of the first sub image. A third area displays a selectable item. The fourth area adjoins both the second area and the third area and is at least partially arranged in between the second area and the third area. The controller changes the aspect of the first sub image if the touch event indicating the change is received in the second area. The controller does not change the aspect of the first sub image if the touch event is received within the third area or the fourth area. And the controller selects the selectable item if the touch event starts within the fourth area and ends within the third area.

The display apparatus allows the user to select the selectable item by starting the touch event in a fourth area. Possibly, due to the effect of parallax or inaccuracies of the movement of the user, the user starts the touch event to select the selectable item outside the third area and inside the fourth area. If the touch event starts inside the fourth area, the fourth area provides the user the possibility to correct for the inaccurate start of the touch event by ending the touch event within the third area. Therefore, the user gets a possibility to correct for the inaccurate start of the touch event. It becomes easier to select the selectable items. An additional benefit of the claimed subject matter is that the correction for the inaccurate start of the touch event does not result in the undesired effect of changing the aspect of the first sub image, because the touch event occurs in the third and fourth area and therefore does not result in changing the aspect of the first sub-image.

The electronic device according to the second aspect of the invention and the method according to the third aspect of the invention provide the user with the same benefits in relation to selecting the selectable item as the display apparatus of the first aspect of the invention.

In an embodiment, the change of the aspect of the first sub image is any of the group of: translation of the first sub image, rotation of the first sub image, reduction or increase of the size of the first sub image, or changing any of the attributes intensity, color balance, contrast, saturation or hue of the first sub image. This embodiment allows the user to correct for the inaccurate start of the touch event outside the selectable item such that it becomes easier to select the selectable item without the undesired effect of translating or rotating the first sub image, increasing or reducing the size of the first sub image or changing any of the attributes intensity, color balance, contrast, saturation or hue of the first sub image. In an embodiment, the touch event comprises a move on the touch screen display and the controller selects the selectable item if the touch event starts in the fourth area, moves into the third area and ends in the third area and wherein the third and fourth area are constructed such that the move from the fourth area to the third area is entirely within the fourth area and the third area. The touch event is the result of an object that is touched onto the touch screen display by the user. The object can be, for example, a finger of the user or a stylus. The touch event starts with a landing on a location on the touch screen display and it may be followed by a movement of the object over the touch screen display without releasing the object from the touch screen display. The touch event ends with releasing the object from the touch screen display at a particular location, which may differ from the location where the object landed on the touch screen display.

The most intuitive way for the user to correct for the inaccurate start of the touch event outside the third area is to move into the direction of the third area, because staying in contact with the touch screen display gives a more accurate feeling for the actual distance that one moves over the touch screen display. Because the touch event starts in the fourth area, and the fourth area adjoins the third area, the object that touches the touch screen display can follow a trajectory over the touch screen display which is completely inside the third area and the fourth area. In addition to this, the fourth area and the third area can be constructed such that every possible trajectory of the move is within the fourth and third area. Staying within the fourth area and third area does not result in the undesired change of the aspect of the first sub image.

In another embodiment, the received change of the aspect of the first sub image in the second area indicates a scrolling of the first sub image in the first area, and the controller is constructed for not scrolling the first sub image in the first area if the touch event occurs in the third area or the fourth area. This embodiment allows the user to correct for an inaccurate landing outside the selectable item such that it becomes easier to select the selectable item without the undesired change of the aspect of the first sub image.

In another embodiment the first area at least partly overlaps the second area. The user experience will be better if the area for receiving the touch event that indicates a change of an aspect of the first sub image at least partially overlaps with the area that displays the first sub image because the overlap partially integrates the location where the touch event occurs and the area where the user sees the result as a change of an aspect of the first sub image. In a further embodiment, the first area comprises the third area. In this embodiment the selectable item is part of the first sub image. Therefore, if the user applies the touch event indicating a movement of the first sub image, the selectable item will move together with the first sub image. If the selectable item is moving, it is not easy to select the selectable item. If the user wants to select the selectable item, and if the user starts the touch event outside the third area but inside the fourth area due to, for example, parallax and user movement inaccuracies, the first sub image and the selectable item will not move. This gives the user an opportunity to correct for the inaccurate start of the touch event, without experiencing the undesired effect of the moving of the selectable item. In another embodiment, the first area coincides with the second area and the third area is surrounded by the fourth area. A complete overlap of the first area and the second area results in a complete integration of the area where the user applies the touch event indicating a change of an aspect of the first sub image and the first sub image itself. This results in a better user experience. The third area that is completely surrounded by the fourth area gives the user the possibility to correct for the inaccurate start of the touch event everywhere just outside the selectable item. Depending on the location from where the user is looking to the touch screen display, the inaccurate landing due to parallax will be to the left of, to the right of, below or above the selectable item. The fourth area which surrounds the fourth area helps the user to correct for the inaccurate start independent of the location from where the user is looking to the touch screen display.

In a further embodiment, the controller generates a second sub image that displays feedback on the touch screen display at the location on the touch screen display where the touch event is received. Feedback will improve user experience, because it makes the user aware of possible differences between the location at which the user assumes the touch event was applied, and the location at which the touch screen display detects the touch event. It helps the user to notice that the start of the touch event is outside the selectable item and to notice a detected location of the touch event on the selectable item.

In another embodiment, the controller generates a second sub image that displays feedback on the touch screen display related to the fourth area. Feedback related to the fourth area makes the user aware of the presence of the fourth area. It increases the probability that the user starts the touch event inside the fourth area and therefore it becomes easier to select the selectable item.

In a further embodiment, the controller generates a second sub image that displays feedback on the touch screen display if the touch event starts in the fourth area. Giving feedback to the user that the touch event starts inside the fourth area helps the user to decide whether he has to continue the touch event such that he can select the selectable item, or that he has to cancel the touch event. There is a possibility that the user did not intend to select the selectable item and that he started by coincidence the touch event inside the fourth area. In this case the feedback helps him to decide to cancel the touch event. On the other hand, if the user had the intention to select the selectable item and feedback is displayed that the touch event starts inside the fourth area, the user is aware of a successful start of the touch event.

In another embodiment, the controller generates a second sub image that displays feedback on the touch screen display if the touch event is inside the third area. Giving feedback to the user that the touch event is inside the third area helps the user to decide whether he can end the touch event and thus select the selectable item, or that he still has to continue the touch event until it is registered within the third area. This improves user experience. In a further embodiment, the dimensions of the fourth area are such that the effects of parallax due to a pre-defined viewing angle of the user and due to a thickness of a transparent plate in front of the touch screen display are at least partly compensated. Parallax is caused by the thickness of the transparent plate in front of the touch screen display and by the viewing angle of the user. The effect of parallax is a difference between the location at which the touch screen display detects the touch event and the location at which the user assumes the touch event is applied. This difference between the locations is a systematic error that is determined by the thickness of the transparent plate and the pre-defined viewing angle. This difference between the locations is at least partly compensated by giving the fourth area large enough dimensions and therefore the touch event will most probably start within the fourth area. A start in the fourth area gives the user the possibility to end the touch event within the third area to select the selectable item.

In another embodiment, the third area has a larger dimension in a first direction than in a second direction, the first direction being different from the second direction, the third area is completely surrounded by the fourth area and wherein the dimensions of the fourth area are such that the distance from the border of the fourth area to the border of third area is larger in the second direction than in the first direction. In this embodiment the first and the second direction are different. In an alternative embodiment the first and the second direction are perpendicular to each other.

An inaccurate start of the touch event for selecting the selectable item depends, amongst others, on the dimensions of the selectable item. For a selectable item which has a larger dimension in one direction than in another direction, it is obvious that most of the inaccurate starts are above or below the selectable item (seen in the direction of the smallest dimension). The fourth area that has dimensions wherein the distance from the outer border of the fourth area to the border of the third area is larger in the direction of the smallest dimension of the third area corrects for this inaccuracy. By providing the fourth area with these dimensions, the probability that the touch event starts within the fourth area is larger, such that the user can continue the touch event and can finish the touch event inside the third area in order to select the selectable item. These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings: Fig. 1 shows a display apparatus according to the invention,

Fig. 2 shows a display apparatus for receiving a touch event indicating a scrolling of the first sub image,

Fig. 3 shows the result of receiving a touch event indicating a scrolling of the first sub image, Fig. 4 shows a display apparatus with a movable sub image comprising a selectable item and shows feedback at the location of the touch event,

Fig. 5 shows feedback on the touch screen display concerning the fourth area, Fig. 6 shows feedback on the touch screen display related to a start of a touch event in the fourth area, Fig. 7 shows feedback on the touch screen display related to receiving a touch event in the third area,

Fig. 8 shows a portable electronic device and shows a fourth area that is large enough to compensate for the effect of parallax and shows another fourth area around a rectangular third area, Fig. 9 shows the effect of parallax due to the thickness of the transparent plate and a non orthogonal viewing angle of the user, and

Fig. 10 shows a flowchart for the method according to the invention.

It should be noted that items which have the same reference numbers in different figures, have the same structural features and the same functions, or are the same signals. Where the function and/or structure of such an item has been explained, there is no necessity for repeated explanation thereof in the detailed description. DETAILED DESCRIPTION OF THE EMBODIMENTS

A first embodiment is shown in figure 1. The figure shows a display apparatus 100 comprising a controller 110 and a touch screen display 105. An image is generated by the controller 110 and displayed on the touch screen display 105. The image comprises a first area 101 displaying a first sub image, a second area 102, a third area 103 and a fourth area 104. A finger 106 of a user touches the screen at a location A. Other locations on the touch screen are marked by B, C and D. A movement from position A to B is indicated by arrow 107. Arrows 108 indicate a movement of the first sub image 101 to a new position, and the dashed lines 109 indicate the new position of the right upper corner of the first sub image 101.

The touch screen display 105 is able to receive a touch event. The touch event is the result of an object which is touched onto the touch screen display 105 by the user. An example of the touch event is the finger 106 of the user touching the touch screen display 105 at position A. The touch event is not limited to the finger 106 touching the touch screen display 105, other objects like a stylus can be used as well.

The touch event which is received in the second area 102 indicates, in this example, the movement of the first sub image 101. The touch event which indicates the movement may comprise the movement of the finger 106 over the touch screen display 105 from position A to position B inside the second area 102. The vector 107 from position A to position B may be a measure for the desired move of the first sub image 101.

The touch event is not limited to one sequence of landing with the touching object on the touch screen display 105, moving the touching object over the touch screen display 105 and releasing the touching object from the touch screen display 105. Another example of the touch event indicating the movement of the first sub image 101 may be two touches of the touching object on two different positions within a given time limit, e.g. first touching the touch screen display 105 at position A followed by a touch of the touch screen display 105 at position B. Again, the vector 107 from A to B indicates the desired movement of the first sub image 101.

If the touch event is received inside the second area 102 and indicates the movement of the first sub image 101 according to the vector 107 from A to B, the first sub image 101 will be moved over the touch screen display 105 by the controller 110. This is indicated by the arrows 108 in figure 1 and the first sub image 101 will get a new position indicated by the dashed lines. The touch screen display 105 displays a selectable item in a third area 103. The selectable item is an object displayed on the touch screen display 105 that can be selected as a result of user input and usually results in additional actions taken by the display apparatus 100. Examples of selectable items are links of internet web pages, selectable menu item, radio and selection buttons of forms, icons on the desktop of a computer operated by an operating system, items of a list wherein a subset of the items can be selected or zoom buttons related to a displayed image.

To select the selectable item, the touch event has to start in the fourth area 104 and has to end in the third area 103. If the touch screen display 105 receives this input, the controller 110 will select the selectable item. In an embodiment, the selection triggers additional specific actions taken by the controller 110 and/or touch screen display 105. In another embodiment, in the case that the touch screen apparatus 100 is part of an electronic device, the selection results in an interrupt given to another part of the electronic device, like for example an interrupt given to a processor of the electronic device. The specific actions taken by the controller are, for example, the generation of a third or fourth sub image, or the generation of a new image comprising a new set of first, second, third and fourth area 101, 102, 103, 104.

The touch event may comprise a landing of the touching object on the touch screen display 105 in the fourth area 104 at position C, a subsequent movement of the touching object over the touch screen display 105 to position D inside the third area 103, and a release of the touching object from the touch screen display 105 at position D. Selecting the selectable item is not limited to a touch event comprising a movement over the touch screen display 105 from a position inside the fourth area 104 to a position inside the third area 103. As discussed before, it is possible to define one touch event as a series of touches of touching objects within a predefined time period. For this type of touch event a touch at position C followed by a touch at position D within the predefined time period results in selecting the selectable item.

When applying the touch event inside the third area 103 and the fourth area 104, the controller 110 will not move the first sub image 101 over the touch screen display 105.

Moving the first sub image 101 over the touch screen display 105 corresponds to translating the first sub image 101 over the touch screen display 105. It should be noted that translating the first sub image 101 over the touch screen display 105 is not the only action that can be indicated by applying the touch event in the second area 102. The received touch event in the second area 102 may indicate other changes of the first sub image 101 as well, such as for example rotating the first sub image 101, reducing or increasing the size of the first sub image 101 or, in an alternative embodiment, zooming into a part of the first sub image 101 within the first area 101 or zooming out of the first sub image 101 within the first area 101. Alternatively, other aspects of the first sub image 101 may be changed such as for example image enhancement aspects: the intensity, colour balance, contrast, saturation or hue, or sharpness. In the case that the touch event is received within the third area 103 or the fourth area 104 and is indicating a change of one of these aspects, the controller 110 is constructed for not changing the aspect of the first sub image 101. In an alternative embodiment an image or video editing program has several selectable items indicating an aspect of the first sub image 101, like intensity, colour balance, contrast, saturation or hue. If the touch event is applied for selecting one of these selectable items, the second area 102 is for receiving the touch event that indicates a change of the aspect which was previously selected. The controller 110 will change the aspect of the first sub image 101 in accordance with the selected aspect and the received touch event.

Figure 2 shows another embodiment of the invention. A display apparatus 200 comprises a touch screen display 205 and a controller (not shown in the figure). First area 201 displays a first sub image comprising text and figures. The text and figures are part of a document which comprises other text and figures. In the example of figure 2, one figure is only partly displayed in the first sub image. A touch event received in the second area 202 indicates a scrolling of the first sub image. Positions E and F are positions inside the second area 202 showing respectively the start position and end position of a movement of the touching object over the touch screen display 205. Vector 206 from E to F is shown as an arrow. In this embodiment, by way of example only, the geometry of third area 203 is a circle and fourth area 204 has the specific geometry shown.

The geometries of the third area 203 and fourth area 204 are constructed such that a move of the touching object 106 from the fourth area 204 into the third area 203 will be entirely within the fourth area 204 and third area 203. This is achieved, for example, by adjoining a main part of the border line of the third area 203 with the border line of the fourth area 204. Or, alternatively, by encapsulating the third area 203 for at least a large part by the fourth area 204. In the case that the union area of the third 203 and fourth area 204 is a convex area, every movement in a straight line from a point in the fourth area 204 to a point in the third area 203 will be entirely within the fourth area 204 and the third area 203. In the example of figure 2, the union area of the third area 203 and fourth area 204 is convex, as well as the union area of the third area 103 and fourth area 104 of the example of figure 1.

A touch event which indicates the scrolling of the first sub image may be the movement of the touching object 106 over the touch screen display 205 in the second area 202. For example, the touching object 106 starts at position E and moves over the touch screen display 205 to position F. The vector 206 from E to F is, for example, a measure for the distance and/or direction of the scrolling of the sub image and in the example of figure 2 it indicates "scrolling in the upwards direction" of the first sub image.

If the touch event is received within the second area 202 the first sub image scrolls in the first area 201. The result is shown in figure 3, where area 301 comprises the first sub image after scrolling. The text and figures of the first sub image of area 201 of figure 2 have been scrolled in the upwards direction and another part of the document is displayed in the bottom part of the first sub image.

Another embodiment is shown in figure 4. This figure shows a display apparatus 400 comprising a touch screen display 405 for displaying an image. Although not shown, the display apparatus 400 comprises a controller as well. The image comprises a first area 401 which coincides with the second area 402, wherein the first area 401 comprises a third area 403, and wherein the third area 403 is completely surrounded by a fourth area 404. Furthermore an object 407 touches the touch screen display 405 and a second sub image 406 is shown which displays feedback at the location where the touch event is received. In this example the object 407 is a stylus.

In this example, the first area 401 displays text. The third area 403 comprises the selectable item. The text and selectable item are for example a web page or a document that is edited in a word processor comprising the selectable item. It should be noted that the controller (110 in Fig. 1) is constructed such that the text of the web page or document is displayed in the fourth area 404 as well.

In this embodiment the touch event that indicates a movement comprises a movement of the object 407 over the touch screen display 405 in the first or second area 401. As a result of the touch event, the controller 110 moves the first sub image over the touch screen display 405 according to the movement of the object 407. The selectable item is part of the first sub image and as a result of receiving the touch event that indicates the movement, the selectable item will move together with the first sub image.

When the user intends to select the selectable item, it might happen that the object 407 does not always land exactly on the selectable item. If the object 407 lands on the touch screen display 405 close to the third area 403, an intuitive reaction of the user is to continue the touch event by moving the object 407 over the touch screen display 405 into the direction of the selectable item. If this touch event occurs completely within the third area 403 or fourth area 404, the controller 110 will not move the first sub image. If the landing is inside the fourth area 404 and the object 407 moves over the touch screen display 405 into the third area 403 and the object 407 is released from the touch screen display 405 within the third area 403, the selectable item is selected by the controller 110 of the display apparatus 400. If the landing is outside the fourth area 404 and third area 403, but inside the first area 401 or the second area 402, and if the user moves the object 407 into the direction of the third area 403 and the fourth area 404, the first sub image will move and the selectable item will move together with the first sub image. In the case that the controller 110 moves the first sub image and the selectable item with the same vector as the vector of the touch event that indicates the movement of the first sub image, the object 407 will not reach the third area 403 or the fourth area 404, because the third area 403 and the fourth area 404 move with the same speed as the object 407 moves.

In another aspect of this embodiment, the second sub image 406 is displayed on the touch screen display 405 at the location where the touch event is received. As soon as the object 407, like the stylus in the figure, touches the touch screen display 405, the controller generates the second sub image 406 which is then displayed on the touch screen display 405. The second sub image 406 can be a pointer or a cross hair at the location where the touch screen display 405 receives the touch event. This improves user experiences because it makes the user aware of a difference between the location where the user assumes the touch event is applied, and the actual location at which the touch screen display 405 detects the touch event. For example, it gives feedback to the user of the start of the touch event being outside the third area 403, and it subsequently helps the user to determine the direction of the movement on the touch screen display 405 such that that the touch event ends in the third area 403. Alternatively, the feedback may be displayed as a circle, a single point, an arrow, or by changing the background or foreground color of the image in a small area. In an alternative embodiment the controller 110 does not move the first sub image if the touch event starts in and occurs within the third area 403 or the fourth area 404. The controller 110 further moves the first sub image in case the touch event starts in the second area 402, occurs in the second area 402, the third area 403 or the fourth area 404 and indicates a movement of the first sub image. It is possible that the vector, which indicates the movement of the first sub image, has a different length than the length of the actual movement of the first sub image. In that case, given the example of figure 4, it is possible to start the touch event in the first area 401 or second area 402, moving the object 407 over the touch screen display 405 and arriving with the object 407 within the third area 403 or the fourth area 404. In that case it would be convenient for the user if the movement of the first sub image continues, although the touch event occurs within the third area 403 or the fourth area 404.

Figure 5 shows the display apparatus 400 which displays a second sub image 500 which comprises feedback related to the fourth area 404. The controller 110 of Fig. 1 is not shown in Fig. 5. In figure 5, a blinking frame around the fourth area 404 is shown. Other examples of feedback are displaying the fourth area 404 in a specific background colour, in a blinking background colour, in a specific background pattern or as a frame of a specific colour.

Figure 6 shows the display apparatus 400 which displays a second sub image 600 which comprises feedback related to the fourth area 404. In this embodiment the feedback is only displayed if the touch event starts inside the fourth area 404. Examples of feedback related to the fourth area are discussed in the Fig. 5 embodiment. If feedback is displayed related to the location where the touch event is received, like the cursor or pointer 406 in figure 4, another example of feedback related to the fourth area 404 is changing an aspect of the displayed cursor or pointer within the fourth area 404. Examples of changing an aspect of the displayed cursor or pointer are: changing the geometry or the colour of the cursor or pointer or setting the cursor or pointer in a blinking state inside the fourth area 404. Figure 7 shows the display apparatus 400 which displays a second sub image 700 comprising feedback related to the third area 403. In this embodiment the feedback is shown when the touch event is received inside the third area 403. In the example of figure 7, the feedback is displayed because the object 407 touches the touch screen display 405 within the third area 403. Examples of feedback related to the third area 403 are to be found in the previously discussed examples of feedback related to the fourth area 404. In this embodiment, if the touch event is received within the third area 403, the feedback can also comprise the change of an aspect of a cursor or pointer which is displayed at the position where the touch event is received.

Figure 8 shows a portable electronic device 800, like a mobile phone, that comprises a display apparatus (not shown in the figure). The display apparatus of the electronic device comprises a controller (not shown in the figure) and a touch screen display 805. The touch screen display 805 displays an image which comprises a first area 801 and second area 802. The first area shows the first sub image. The specific first sub image of the example of figure 8 comprises two selectable items: a selectable picture 803 and a rectangular selectable item 806. Above the selectable picture 803 a fourth area 804 is provided that is large enough to compensate for the effect of parallax. The rectangular selectable item 806 is larger in a first direction 808 than in a second direction 809. Another, fourth area 807 is provided around the rectangular selectable item 806. The distance from the border 810 of the fourth area 807 to the border of the third area 806 is larger in the second direction 809 than in the first direction 808.

Figure 9 show a side view of a cross section of the touch screen display 805 of the portable electronic device 800 at the location of the dashed line 811 in figure 8. Figure 9 shows a display with a touch sensitive layer 900, and an eye 902 of a user. A transparent plate 901 is arranged in front of the touch sensitive layer 900. The transparent plate 901 and the display with touch sensitive layer 900 form the touch screen display 805 of figure 8. The transparent plate 901 may be a glass plate. The touch sensitive layer 900 may be supported by the transparent plate 901. The user views the touch screen display 805 with a viewing angle φ in relation to an axis 904 perpendicular to the transparent plate 901 and looks to position G on the display with touch sensitive layer 900. The light beam 903 from G to the eye 902 of the user will follow the path from G, to H and to the eye 902. This light beam 903 traverses through the transparent plate 901 at another angle φ' in relation to the axis 904 perpendicular to the transparent plate 901 than the viewing angle φ. Refraction at the location of point H causes the differences between angles φ and φ'. Therefore, the user will experience position G' to be the position of G. If the user wants to apply the touch event to the transparent plate 901 such that he touches the transparent plate 901 at the location which corresponds to G, he will most probably touch the transparent plate 901 at a location close to point I' instead of a location close to point I.

In most cases the user of the portable electronic device 800 views the touch screen display 805 with a non orthogonal viewing angle φ . If the eye 902 of the user is orthogonally projected on a plane through the touch screen display 805 of the portable electronic device 800, the projection will be in front of the portable electronic device 800, which is indicated by point P in figure 9. Seen from point P, point G' is above point G. Due to parallax, an inaccurate start of the touch event will most probably start above the selectable item 801. If the transparent plate 901 is thicker, or the viewing angle φ is larger, the difference between positions G and G' will be larger. Therefore, knowing the thickness of the transparent plate 901 in front of the touch sensitive layer 900 and by defining a maximum viewing angle φ, the fourth area 804 can be made sufficiently large to correct for the expected difference between the location at which the user assumes he applies the touch event and the location where the touch screen display 805 detects the touch event. Other inaccurate starts of touch events that can be predicted are inaccuracies related to the rectangular selectable item 806. There is a higher probability that the object lands correctly on the rectangular selectable item 806 in the first direction 808 where the rectangle is longer than in the second direction 809. Therefore, the inaccuracies will be larger in the second direction 809 where the rectangle is smaller. Therefore, the distance between the outer border 810 of the fourth area 807 to the border of the selectable item 806 may be selected to be larger in the second direction 809 where the rectangular selectable item 806 is smaller. It should be noted that selectable items which are larger in one direction than in the other direction are not limited to rectangular selectable item 806. Other geometries for such selectable items are e.g. an ellipse or a polygonal geometry which is larger in one direction than in another direction.

A mobile phone is not the only portable electronic device in which the display apparatus can be used. Other examples of mobile electronic devices are organizers and laptops. The display apparatus can also be used in electronic devices such as screens of computers or screens which are built in, for example, a table and are used for playing games. Figure 10 shows a flowchart of the method of the invention. In step 1001 of the method of the invention an image is generated comprising the first, second, third and fourth area 101, 102, 103, 104. In step 1002 the image is displayed on the touch screen display 105. In step 1003 a touch event is received from the touch screen display 105. In step 1004 of the method of the invention it is decided if the touch event which indicates a change of an aspect of the first sub image is received in the second area 102. If this is true, then in step 1005 an aspect of the first sub image will be changed on the touch screen display 105. In step 1006 of the method of the invention it is decided if the touch event occurs within the third area 103 or the fourth area 104. If this is true, then in step 1007 the aspect of the first sub image is not changed. In step 1008 of the method of the invention it is decided if the touch event starts within the fourth area 104 and ends within the third area 103. If this is true, then in step 1009 the selectable item is selected.

It should be noted that the geometries of the four areas are not limited to rectangles and circles and the shown geometries in the figures. The areas can be of all kind of polygonal and non-polygonal geometries. It should be noted that the embodiments of the invention are not limited to an image comprising only the four areas and touch events indicating a change of an aspect of the first sub image, or a selection. Other touch events, like for example a touch event indicating the shut down of the display apparatus, can be received in the same or different areas of the touch screen display as well.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.