WO2009027895A1

WO2009027895A1 - Image display device

Info

Publication number: WO2009027895A1
Application number: PCT/IB2008/053286
Authority: WO
Inventors: Ewout Brandsma
Original assignee: Nxp B.V.
Priority date: 2007-08-28
Filing date: 2008-08-15
Publication date: 2009-03-05

Abstract

An image display device (10) defines a format selection condition. The format selection condition may select images in landscape format, or another condition may select images in portrait format. The condition may be selected dependent on a sensor output of an orientation sensor in the image display device. Images are provided in a memory. At least part of the images is displayed successively. A control circuit (104) selects durations of display of the images, for each image at least partly dependent on whether a format of the image satisfies the format selection condition. A zero duration (i.e. no display) or a shortened duration is selected when the format of the image does not satisfy the format selection condition. Thus there is no need for the user to prepare the images for display on the display device in a visually effective way.

Description

IMAGE DISPLAY DEVICE

FIELD OF THE INVENTION

The invention relates to an image display device.

BACKGROUND OF THE INVENTION From US patent application No 2004/0201595 a photo viewing device is known that rotates images according to the orientation of the device.

The device comprises a rotation sensor. The device comprises a rectangular display screen, a rotation sensor, an image data memory and a computation unit. The display screen may be oriented with its longest side horizontally (landscape orientation) or with its longest side vertically (portrait orientation). The image data memory stores data that represents an image, which have a horizontal side that is longer or shorter than its vertical side (landscape and portrait format, respectively). When the image is in landscape format and the rotation sensor detects that the device is in portrait orientation, the computation unit computes data representing a 90-degree rotated version of the image and uses this computed data to control the content of the display screen. Similarly, if the image is in portrait format and the device is in landscape orientation, a 90-degree rotated version of the image is computed and used to control display.

In either case black bars, or other supplementary information has to be displayed adjacent to the image. This makes sub-optimal use of the display capabilities and degrades the pleasure of viewing the image, even if the visual effect is minimized by displaying bars in the color of the frame of the display screen.

SUMMARY OF THE INVENTION

Among others it is an object to provide for an image display device wherein better use is made of the display capabilities of the display screen.

A device according to claim 1 is provided. This device successively displays images from a memory on a display screen. Herein a zero display duration or a shortened display duration is selected for an image when a format of the image does not satisfy a format selection condition. In an embodiment, the format selection condition is selected from a plurality of conditions based on the output of an orientation sensor in the display device. By using a zero duration, i.e. by not displaying images with the wrong format for the current orientation of the display, wasted display area is avoided. Thus a user is shown a sequence of images in an adapted way. As an alternative, use of a shorter but non-zero duration for non matching images at least ensures that at least less display area is wasted during less of the time.

The images may be part of respective video sequences, in which case only the video sequences may be played on the display screen wherein a format of the images in the video sequence matches the sensed orientation. The images may be taken from a memory an apparatus that is not part of the display device and communicated to the display device via a network. Because the device selects only images with a suitable format , there is no need for a user to prepare such external images to realize a visually effective display dependent on the particular display device.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantageous aspects will become apparent from a description of exemplary embodiments, using the following Figures: Fig. 1 shows an assembly containing a display device. Fig. 2 shows a flow chart of operation of a control circuit.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Fig. 1 shows an assembly containing a display device 10 and a memory 12. Display device 10 comprises a display screen 100, an orientation sensor 102, a control circuit 104 and an interface 106 for connecting memory 12 to display device 10. Control circuit 104 is coupled to display screen 100, orientation sensor 102 and interface 106. Interface 106 may be a connector for example, or a wireless communication interface or a communication network. Memory 12 may comprise a plurality of memory devices. It may be part of display device 10, or external to it. Control circuit 104 may be implemented as a programmable processor that is programmed to perform the operations described below. Alternatively, a dedicated control circuit 104 may be used that is hardwired to perform these operations.

Fig. 2 shows a flow chart of operation of control circuit 104. In a first step 21 control circuit 104 reads memory 12 to determine whether it stores data representing a first image. From this step control circuit 104 handles the first image as a current image. In a second step 22 control circuit 104 reads orientation sensor 102. Sensor 102 may be configured for example to measure an angle between a vertical axis and the direction of the longest edge of display screen, or at least to measure whether this angle exceeds a threshold. Alternatively, sensor 102 may be configured to measure an angle between a vertical axis and the direction of the shortest edge of display screen, or the direction of any other line in the plane of display screen 100, or detect whether this angle exceeds a threshold.

Dependent on a sensor result, control circuit 104 selects a format selection condition in this second step 22. A first format selection condition may select only images with portrait orientation for example, and a second format selection condition may select only images with landscape orientation. The first or second condition may be selected dependent on whether the orientation indicates that the shortest or longest edge of the display screen is in a horizontal orientation.

In a third step 23 control circuit 104 tests whether the format of the current image satisfies the selected format selection condition. Herein, the format of an image corresponds to the relation between the lengths of the horizontal and vertical axes of the image: if the horizontal axis is longer than the vertical axis, the image is said to have landscape format and if the horizontal axis is shorter than the vertical axis, the image is said to have portrait format. In some data representing image the format is indicated explicitly. The comparison of third step 23 may include reading an indication of the format to determine the format, or reading horizontal and vertical image size and selecting the format from a comparison of these sizes. The format determined for the image is compared with the format selection condition.

If the format satisfies the condition, control circuit 104 executes a fourth step 24, controlling display device to display the current image. Subsequently, control circuit 104 executes a fifth step 25, waiting a predetermined amount of time while the current image is displayed (this amount of time may be selected by a user via a user interface (not shown) of the device). After fifth step 25 control circuit 104 executes a sixth step 26 to select a next image stored in memory 12 and control circuit 104 returns to second step 22 using the selected next image as current image. In an embodiment, at least some of the images stored in memory 12 are each part of a respective video sequence, wherein each video sequence has its own format (portrait or landscape). In this embodiment, the video sequence may be replayed during fifth step 25. The format of the images may be determined from a format of the video sequence. Video replay or persistent display of an image in fifth step 25 may be performed by repeated writing from control circuit 104 in fifth step 25, or by an autonomous part of the control circuit 104, which is activated in fourth step 24 and which remains active for example until the next execution of fourth step 24.

If the result of third step 23 is that control circuit 104 finds that the format does not satisfy the format selection condition, control circuit 104 immediately proceeds to sixth step 26, skipping both the start of display of the current image in fourth step 24 and waiting in fifth step 25. Thus, only a subset of images will be displayed that has a format that matches the orientation parameter determined for the display device 10. When the orientation of the display device 10 is changed, only images from a different subset will be displayed. It should be realized that the flow chart is merely shown by way of example.

Variations of the process are possible that produce a similar effect. For example, control circuit 104 may configured to read data representing all images from memory 12 first, to select a plurality of images with format that satisfies the format selection condition determined from orientation sensor 102, followed by successive display of the images from the selected plurality. In this case, the selection step need be repeated only when the orientation of the display device is detected to change the format selection condition from landscape to portrait orientation or vice versa. As another example, the images without matching format (i.e. with a formats that does not satisfy the format selection condition) could be displayed for a shorter time than images with matching format, for example by skipping only the waiting step (fifth step 25) for non-matching images, or by waiting less time for non-matching images. The duration for matching images may be selected as a predetermined value, or in any other way. Compared to the duration that would be selected if the image matches, a shorter duration is selected when the image does not match. The shorter duration is preferably zero, so that the image is not shown, i.e. as used herein selection of duration may comprise selecting not to display, as this corresponds to zero duration.

Alternatively a predetermined short duration may be used for non-matching images that it preferably so short that the images are not noticed, e.g. less than a tenth of a second, or not recognizable, e.g., for less than a second. Instead of using only two formats (landscape and portrait) a greater number of formats may be used, for example by including an orientation parameter with the images, which indicates the orientation at which the image should be viewed as one angle from a set of more than two angles. As used herein, such a parameter is also said to define a format of the image. In this case a comparison with a greater number of possible orientations may be made to select only the images with matching format for display. Although an embodiment is used wherein orientation sensor 102 is used to select one of a plurality of predetermined format selection conditions, in another embodiment the orientation sensor 102 may be omitted. In this embodiment manual selection of a format selection condition may be used, or a preprogrammed format selection condition may be implemented in control circuit 104. Also the format selection conditions need not be limited to selecting landscape format or portrait format. For example, a format selection condition could select images with aspect ratio's (length width ratio's) in a predetermined range that matches the aspect ration of the display screen, e.g. 4:3 or a range of aspect ratio's containing the ratio of 4:3. Similarly, another a format selection condition could select images with an aspect ratio of 16:9 or in a range containing that value.

Memory 12 may be a semiconductor memory, a hard disc drive of any other device or system that provides for retrieval of stored image data, or it may comprise a plurality or a combination of such devices. In an embodiment memory 12 is coupled to the display device via communication network, e.g. a wireless communication network. Thus, the memory may be part of a personal computer or another apparatus. In this case the memory may store a collection of images that has not been specifically selected for use in the display device 10. In this embodiment the effect of the display device 10 is that the collection of images is made suitable for visually acceptable display on display device 10 without requiring user intervention. A cache local memory may be included in display device 10 to store copies of images from memory 12 for use during display. Although memory 12 is shown as external to the display device 10, it should be realized that in an alternative embodiment memory 12 may be internal to display device 10, in which case interface 106 may be replaced by another type of memory interface.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS:

1. An image display device (10), comprising: an interface (106) to a memory (12) for storing data representing a plurality of images; a display screen (100) for displaying the images; - a control circuit (104) coupled to the interface (106) and the display screen

(100), the control circuit (104) being configured to define a format selection condition, the control circuit (104) being configured to control the display screen (100) to display at least part of the images temporally successively, the control circuit (104) being configured to select durations of display of the images, for each image at least partly dependent on whether a format of the image satisfies the format selection condition, a zero duration or a shortened duration being selected when the format of the image does not satisfy the format selection condition.

2. An image display device according to claim 1, comprising an orientation sensor (102) coupled to the control circuit (104), for sensing a spatial orientation of the display screen (100) relative to a vertical direction, the control circuit (104) being configured to select the format selection condition dependent on the sensed orientation.

3. An image display device according to claim 1, wherein the control of duration by the control circuit (104) comprises making the duration zero when the format of the image does not match the sensed orientation.

4. An image display device according to claim 2, wherein each image has a landscape and/or portrait format, the format selection condition selecting portrait format images when the orientation sensor (102) indicates that a longest side of the display screen

(100) makes a larger angle with a vertical axis than a shortest side of the display screen (100), and landscape format images otherwise.

5. An image display device according to claim 1, wherein at least part of the images are part of respective video sequences, the control circuit (104) being configured to display only the video sequences wherein a format of the images in the video sequence satisfies the format selection condition.

6. An image display device according to claim 1 wherein the interface (106) comprises a communication network, the memory (12) being part of an apparatus outside the image display device (10).

7. An image display device according to claim 1, comprising the memory (12), the interface being an internal interface in the image display device (10).

8. A method of displaying images on a display screen (100), the method comprising: - providing a memory (12) wherein is stored that represents a plurality of images; defining a format selection condition; controlling the display screen (100) to display at least part of the images temporally successively, - controlling durations of display of the images, for each image at least partly dependent on whether a format of the image satisfies the format selection condition, a zero duration or a shortened duration being selected when the format of the image does not satisfy the format selection condition.

9. A method according to claim 8, comprising: using an orientation sensor (102) to sense an orientation of the display screen (100); selecting the format selection condition dependent on the sensed orientation.