WO2005120083A1

WO2005120083A1 - Apparatus for displaying images utilising liquid crystal shutter glasses

Info

Publication number: WO2005120083A1
Application number: PCT/GB2005/001458
Authority: WO
Inventors: Anthony Marc Scott; John Robert Harding
Original assignee: Seos Limited
Priority date: 2004-06-02
Filing date: 2005-04-15
Publication date: 2005-12-15
Also published as: GB0412298D0; GB2414883A

Abstract

Apparatus (2) for displaying stereoscopic images utilising liquid crystal shutter glasses, which apparatus (2) comprises a primary image data source (4) which provides image data at a first frame rate, at least one secondary image data source (6) which provides image data at a second frame rate which is different from the first frame rate, framestore means (8) for storing the image data from the secondary image data source (6), image combining means (10) for combining the image data from the primary image data source (4) with the image data from the framestore means (8), display means (12) for displaying combined images from the image combining means (10), liquid crystal shutter glasses (16) for enabling a person to view the display from the display means (12), and control means (14) for controlling the operation of the liquid crystal shutter glasses (16).

Description

APPARATUS FOR DISPLAYING IMAGES UTILISING LIQUID CRYSTAL SHUTTER GLASSES

This invention relates to apparatus for displaying images, and more especially, this invention relates to apparatus for displaying stereoscopic images utilising liquid crystal shutter glasses. Apparatus for displaying stereoscopic images utilising liquid crystal shutter glasses is well known. The displayed stereoscopic images are often known as active stereo displays. The apparatus may use, for example cathode ray tubes, digital light processing technology, or liquid crystal displays. The apparatus may be one in which a left eye image and a right eye image are displayed alternately. A person wishing to view the stereoscopic images wears the liquid crystal shutter glasses. The action of the liquid crystal shutters is synchronised to the display, usually by way of an infra-red link. The liquid crystal shutter glasses operate such that when the display is displaying the left eye image, then the right shutter of the liquid crystal shutter glasses is closed. Similarly, when the right eye image is displayed, then the left shutter of the liquid crystal shutter glasses is closed. This method of operation ensures that left eye images are only viewed by the left eye of the person viewing the images, and the right eye images are only viewed by the right eye of the person viewing the images. Single channel or multi-channel projected active stereo displays are widely used in the oil and gas industries. The active stereo displays are used to view seismic data, with different software applications being used to display the data to different disciplines within the industry. Thus, for example, geologists may use a first software application to view the specific seismic date. Oil drillers may use a second software application to view the data. Pipeline engineers may use a third software application to view the data. This third software application may take the form of computer-aided design software. The various software applications are all capable of displaying the data as an active stereo display. At present, it is only possible to view one of these applications at a time on the display. The reason for this is that the various software applications display the images at differing frame rates, resulting in the liquid crystal shutter glasses being synchronous with only one of the software applications at any time. Thus only one of the software applications can be viewed at a time. It is an aim of the present invention to obviate or reduce the above mentioned problem. Accordingly, in one non-limiting embodiment of the present invention there is provided apparatus for displaying stereoscopic images utilising liquid crystal shutter glasses, which apparatus comprises a primary image data source which provides image data at a first frame rate, at least one secondary image data source which provides image data at a second frame rate which is different from the first frame rate, framestore means for storing the image data from the secondary image data source, image combining means for combining the image data from the primary image data source with the image data from the framestore means, display means for displaying combined images from the image combining means, liquid crystal shutter glasses for enabling a person to view the display from the display means, and control means for controlling the operation of the liquid crystal shutter glasses. The apparatus of the present invention is preferably for displaying stereoscopic images but it may display mono images if desired. More specifically, the image data sources which are able to be combined by the apparatus of the present invention may be mono image data sources, stereo image data sources providing alternate left and right eye images, or a combination of mono and stereo image data sources. A person viewing the display is able to view all parts of the combined image because the liquid crystal shutter glasses are able to be synchronised to the first frame rate, and the first frame rate is able to be matched to the second frame rate via the framestore means. If the primary image data source is a stereo image data source, and the secondary image data source is also a stereo image data source, then the viewer will be able to see stereo images on all parts of the display. The apparatus of the present invention is capable of displaying active stereo images from one or more image data sources. The apparatus may be single or multiple channel, directly viewed or projected onto a screen. As indicated above, the primary image data source provides image data at the first frame rate. This is typically a software application for displaying image data in a certain format. The secondary image data source is also typically a software application. However, the secondary image data source provides the image data at the second frame rate which is different from the first frame rate. The second frame rate may be higher than the first frame rate. Alternatively, the second frame rate may be lower than the first frame rate. The apparatus of the present invention is able to take source data from more than one application and combine it such that the viewer is able to view all of the applications when displayed, via the liquid crystal shutter glasses. This overcomes the above mentioned problem, and in particular the problem encountered by the different disciplines working within the oil and gas industries. For example, the apparatus enables seismic data to be viewed by a geologist concurrently with computer-aided design software being viewed by pipeline engineers. The ability to show combined images from more than one data source, and especially in the form of combined stereoscopic images, is extremely advantageous when gathering information from the field as occurs in the oil and gas industries. The apparatus of the present invention may be one in which the primary image data source is a stereo image data source which provides alternate left and right eye images. The apparatus may alternatively be one in which the secondary image data source is a stereo image data source which provides alternate left and right eye images. The apparatus may alternatively be one in which the primary image data source and the secondary image data source are stereo image data sources which provide left and right eye images. The apparatus may be one in which there is a plurality of the secondary image data sources. Preferably, at least one of the plurality of the secondary image data sources is a stereo image data source. Alternatively, the plurality of secondary image data sources may be stereo image data sources providing left and right eye images. The apparatus may be one in which the primary image data source is a stereo image data source which provides alternate left and right eye images which form a background of the combined images. The apparatus may be one in which the primary image data source is a stereo image data source which provides alternative left and right eye images which form a background of the combined images, and in which the secondary image date source is inserted within the background. In this embodiment of the invention, the apparatus may be one in which the secondary image data source is an insert within the background, and in which the insert is able to be resized within the background. In this embodiment of the invention, the secondary image data source is preferably a stereo image data source which provides alternate left and right eye images. The apparatus may be one in which the framestore means is a double buffer framestore. Alternatively, the framestore means may comprise a double buffer framestore for left eye images, and a double buffer framestore for right eye images. Alternatively, the framestore means may comprise a plurality of double buffer framestores. The image combining means comprise software means. The software means may be a windowing software means. Other types of software means may be employed. The image combining means may alternatively comprise hardware means. Preferably, the display means is a cathode ray tube display means, a liquid crystal display means, a digital light processing display means, a plasma display panel display means, a light emitting diode display means, or an organic light emitting diode display means. The display means may be a front or rear projected display means. The display means may be a single channel display means. Alternatively, the display means may be a multi-channel display means. The control means may control the liquid crystal shutter glasses to be synchronous with the frame rate of the primary image data source. Alternatively, the control means may control the liquid crystal shutter glasses to be synchronous with the frame rate of the secondary image data source. In order to facilitate a full and complete understanding of the apparatus of the present invention, there will now be given a description of how an embodiment of the apparatus may generally operate. More specifically, image data from the primary image data source is fed directly to the image combining means. The image combining means combines images from more than one image source such that the combined images are able to be displayed. This may be achieved using appropriate software or hardware. The combining means may set the primary image data source as the background, combining the images from the secondary image data source as inserts or windows within the background. The inserts or windows can be placed anywhere within the background image, and also resized within the background. Alternatively, the primary image data source can be inserted into the display at a first location, and the secondary image data sources inserted at different locations. Before the image data from the secondary image data source can be fed to the combining means, the image data is first held in the framestore means. Image data from the secondary image data source is input into the framestore means at the second frame rate which is different to the first frame rate of the primary image data source. The output from the framestore means to the image combining means matches the frame rate of the primary image data source. This is achieved by the action of the framestore means. If the second frame rate is higher than the first frame rate, then the framestore means functions that certain frames from the secondary image data source are repeated. This effectively increases the second frame rate so that it now matches the first frame rate. If the first frame rate is lower than the second frame rate, then the framestore means functions such that certain frames in the second frame rate are ignored. This effectively reduces the second frame rate so that it matches the first frame rate. The combined image is now displayed on the display means which can be a single channel display means or a multi-channel display means. The combined image is displayed with a frame rate that is common to all parts of the display. Thus, for example, a background image from the primary image data source may have the same frame rate as an inserted image taken from the secondary image data source. The person views the display using the liquid crystal shutter glasses. The liquid crystal shutter glasses are synchronised to the first frame rate by the control means. As all parts of the display are now displayed with a common frame rate, the second frame rate having been adjusted by the framestore means such that it matches the first frame rate, the viewer is now able to see all parts of the display satisfactorily via the liquid crystal shutter glasses. The apparatus enables both mono image data sources, stereo image data sources or a combination of mono and stereo image data sources to be combined for viewing on the display via the liquid crystal shutter glasses. When the secondary image data source is a stereo image data source, then the framestore means must normally include a framestore for the left eye images and a framestore for the right eye images. If more than one secondary image data source is used, then a framestore is normally needed for each of these secondary image data sources. For any of the secondary image data sources which are stereo image data sources, then a framestore will normally be needed for the left eye images and also a framestore will be needed for the right eye images. Any suitable and appropriate display means may be employed. The display means should normally be capable of displaying images at a high enough frame rate in order to eliminate flicker and other artifacts from being seen by the viewer when viewed via the liquid crystal shutter glasses. As indicated above, the display means may be a single channel or multichannel display means. The display means may be a front or a rear projected display means. The single or multi-channels may be directly viewed displays utilising cathode ray tubes or liquid crystal display monitors. Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 shows schematically apparatus for displaying images utilising liquid crystal shutter glasses; Figure 2 is a detailed block diagram of framestore means utilised in the apparatus of the present invention; Figure 3 is an alternative detailed block diagram of framestore means able to be used in the apparatus of the present invention; Figure 4 shows a first display from the apparatus of the present invention; Figure 5 shows a second display from the apparatus of the present invention; Figure 6 shows a third display means from the apparatus of the present invention; Figure 7 shows schematically framestore means used in a mono- application; Figure 8 shows schematically framestore means used in an alternative mono-application; and Figure 9 shows framestore means used in a stereo application. Referring to the drawings, Figure 1 shows schematically apparatus 2 for displaying images utilising liquid crystal shutter glasses. The apparatus 2 comprises a primary image data source 4 which has a first frame rate and which inputs into image combining means 10. A secondary image data source 6 has a second frame rate that inputs into framestore means 8. The framestore means 8 outputs to the image combining means 10. The output of the framestore 8 has a frame rate which is now compatible with the frame rate of the primary image data source 4. The image combining means 10 combines the image data from the primary image data source with the image data from the framestore means 8 for display on display means 12. A person wishing to view the display on the display means 12 uses liquid crystal shutter glasses 16. The operation of the liquid crystal shutter glasses 16 is controlled by a control means 14, via a remote link 18. The remote link 18 is an infra-red link but other remote links may be employed. The control means 14 determines the frame rate at which to operate the liquid crystal shutter glasses 16 by information fed from the primary image data source 4. The primary image data source 4 provides image data at a first frame rate. The secondary image data source 6 provides image data at a second frame rate which is different to the first frame rate. Figure 2 shows a part 20 of the apparatus of the invention. In the part 20, there is shown the operation of framestore means 30. More specifically, there is shown the operation of the framestore means 30 with a mono-primary image data source 22 and a mono-secondary image data source 24. The primary image data source 22 has a first frame rate which inputs into image combining means 28. The secondary image data source 24 has a second frame rate which inputs into the framestore means 30. The framestore means 30 comprises a state machine 36 which controls the input to framestores 32A, 34B. A state machine 38, controls the outputs from the framestores 32A, 34B. The frame rate of the primary image data source 22 is lower than the frame rate of the secondary image data source 24. It is the lower of the frame rates which covers the operation of the state machines. In this case, the state machine 38 operates at the start of every frame, as it is operating at the lower frame rate, and it is referred to as the master. The output is switched from framestore A to framestore B and vice versa at the start of each frame. A state machine 36, controlling the input to framestore A and framestore B, operates in dependence upon the master state machine 38. At the start of an input frame, the state machine 36 will switch to the opposite state of the master state machine 38. If the slower master state machine 38 has not switched, the next frame will be input into the same framestore. Figure 7 shows this in more detail. Figure 3 shows a part 40 of the apparatus of the invention. In the part 40 there is shown the operation of framestore means 50. More specifically, there is shown the operation of the framestore means 50 with a mono-primary image data source 42 and a mono-secondary image data source 44. The primary image data source 42 has a first frame rate which inputs into image combining means 48. A secondary image data source 44 has a second frame rate which inputs into the framestore means 50. The framestore means 50 comprises a state machine 56 which controls the input to framestores 52A, 52B. A state machine 58 controlling the outputs from the framestores 52A, 54B. The frame rate of the primary image data source 42 is higher than the frame rate of the secondary image data source 44. It is the lower of the frame rates which covers the operation of the state machines. In this case, the state machine 56 operates at the start of every frame, as it is operating at the lower frame rate, and it is referred to as the master. The input is switched from framestore A to framestore B and vice versa at the start of each frame. The state machine 58 controls the output from the framestores A and B. The state machine 58 operates in dependence upon master state machine 56. At the start of an input frame, the state machine 58 will switch to the opposite state of the master state machine 56. If the slower master state machine 56 has not switched, then the next frame will be output from the same framestore. Figure 8 shows this in more detail. Figure 4 shows a display 60. In the display 60, a background area 62 is formed from information from the primary image data source. An insert area 64 is formed from information supplied by the secondary image data source. The insert area 64 is inserted into the background by the image combining means. To a viewer, the display appears to be a single display. Figure 5 shows a display 66. The display 66 has a background area 68 of a combined image, with an insert area 70 that has been re-sized within the background area 68. Figure 6 shows a display 72 in which a combined image is formed by combining information from the primary image data source and the secondary image data source. In the embodiment of the invention shown in Figure 6, the display has a background 74 with no information, a region 76 containing image data from the primary image data source, and a separate region 78 containing data from the secondary image data source. Figure 7 shows schematically framestore means used in a mono- application. Time is indicated at the top of Figure 7. The primary image data source has the lower frame rate. The primary image data frames indicated have a frame rate of 75Hz and are numbered B0, B1, B2, etc. with the last frame of each cycle being B74. The secondary image data frames indicated have a frame rate of 100Hz and are numbered I0, 11, 12, etc. with the last frame in each cycle being I99. Image data from the secondary image data source is input to the framestore means, which comprises framestore A and framestore B. Inputs and outputs are determined as previously described with reference to Figure 2. The combined image data shown indicates which frames are selected to make up the combined image. The shaded frames in the framestore means indicate those frames which are dropped from the secondary image data source in order to synchronise the image data from the two sources on a frame by frame basis. The frames are dropped on a regular basis from the secondary image data source, i.e. frames 10, 14, 18, 112, etc. The combined image frame rate is the same as the primary image data source frame rate. Figure 8 shows framestore means in a second mono-application. Time is indicated at the top of Figure 8. The primary image data source in Figure 8 has the higher frame rate. The primary image data frames indicated have a frame rate of 75Hz and are numbered B0, B1, B2, etc. with the last frame of each cycle being B74. The secondary image data frames indicated have a frame rate of 60Hz and are numbered I0, 11, 12, etc. with the last frame of each cycle being I59. Image data from the secondary image data source is input to the framestore means, which comprises framestore A and framestore B. Inputs and outputs in Figure 8 are determined as previously described with reference to Figure 3. The combined image data shown indicates which frames are selected to make up the combined image. The shaded frames in the framestore means indicate those frames which are repeated from the secondary image data source in order to synchronise the image data from the two sources on a frame by frame basis. The frames repeat on a regular basis from the secondary image data source, i.e. frames 13, 17, 111, etc. The combined image frame rate is the same as the primary image data source frame rate. Figure 9 shows framestore means in a stereo-application. Time is indicated at the top of the Figure 9. The frames in Figure 9 in both the primary image data source and the secondary image data source are alternate left eye and right eye images. The frames in this case are treated as pairs in order to keep the correct left eye image with the associated right eye image. With stereo images, the framestore means must include a framestore A (left) with a framestore A (right) and a framestore B (left) with a framestore B (right). Switching of framestores always occurs at the start of a left eye/right eye pair of frames. The primary image data source in Figure 9 has the lower frame rate. The primary image data frames indicated have frame rate of 72Hz and are numbered BOL, BOR, B1L, B1R, etc. in pairs with the last frame pair of each cycle being B35L, B35R. The secondary image data frames indicated have a frame rate of 96Hz and are numbered I0L, I0R, 11 L, MR, etc. with the last frame of each cycle being I47L, I47R. Image data from the secondary image data source is input to the framestore means, which comprises framestore A (left), framestore A (right) and framestore B (left) and framestore B (right). Inputs and outputs to the framestore means are determined as previously described with reference to Figure 2. The combined image data shown indicates which frames are selected to make up the combined image. The shaded frames in the framestore means indicate those frames which are dropped from the secondary image data source in order to synchronise the image data from the two sources on a frame by frame basis. The frames are dropped on a regular basis and, more specifically, using stereo images, the frames are dropped on a frame pair basis. The frames are dropped regularly in the sequence lOL/IOR, I4L/I4R, etc. The combined image frame rate is the same as the primary image data source frame rate. It will be appreciated from the above that the apparatus of the present invention will work if the frame rate of the primary image data source is a stereo data source with a frame rate higher than that of the secondary image data source. The apparatus of the present invention will also work with more than one secondary image data source by increasing the number of framestores within the framestore means. The apparatus of the present invention also enables stereo and mono images to be combined. Figures 7, 8 and 9 demonstrate that the combined image, that is the image output the display means, has a frame rate and format that are coincident with that of the primary image data source. This indicates that when the person wishing to view the display uses the liquid crystal shutter glasses synchronised to the primary image data source, then the person will be able to view the combined images as these are also synchronous with the primary image data source. It is to be appreciated that the embodiments of the invention described above have been given by way of example only and that modifications may be effected.

Claims

1. Apparatus for displaying stereoscopic images utilising liquid crystal shutter glasses, which apparatus comprises a primary image data source which provides image data at a first frame rate, at least one secondary image data source which provides image data at a second frame rate which is different from the first frame rate, framestore means for storing the image data from the secondary image data source, image combining means for combining the image data from the primary image data source with the image data from the framestore means, display means for displaying combined images from the image combining means, liquid crystal shutter glasses for enabling a person to view the display from the display means, and control means for controlling the operation of the liquid crystal shutter glasses.

2. Apparatus according to claim 1 in which the primary image data source is a stereo image data source which provides alternate left and right eye images.

3. Apparatus according to claim 1 in which the secondary image data source is a stereo image data source which provides alternate left and right eye images.

4. Apparatus according to claim 1 in which the primary image data source and the secondary image data source are stereo image data sources which provide left and right eye images.

5. Apparatus according to claim 4 in which each of the image data sources is a separate region of the display.

6. Apparatus according to claim 1 in which there is a plurality of the secondary image data sources.

7. Apparatus according to claim 6 in which at least one of the plurality of the secondary image data sources is a stereo image data source.

8. Apparatus according to claim 6 in which the plurality of the second image data sources are stereo image data sources providing left eye and right eye images.

9. Apparatus according to claim 2 in which the primary image data source is a stereo image data source which provides alternate left and right eye images which form a background of the combined images.

10. Apparatus according to claim 2 in which the primary image data source is a stereo image data source which provides alternate left eye and right eye images which form a background of the combined images, and in which the secondary image data source is inserted within the background.

11. Apparatus according to claim 10 in which the secondary image data source is an insert within the background, and in which the insert is able to be resized within the background.

12. Apparatus according to claim 11 in which the secondary image data source is a stereo image data source which provides alternate left and right eye images.

13. Apparatus according to any one of the preceding claims in which the framestore means is a double buffer framestore.

14. Apparatus according to any one of claims 1 - 12 in which the framestore means comprises a double buffer framestore for left eye images, and a double buffer framestore for right eye images.

15. Apparatus according to any one of claims 1 - 12 in which the framestore means comprises a plurality of double buffer framestores.

16. Apparatus according to any one of the preceding claims in which the image combining means comprises software means.

17. Apparatus according to claim 16 in which the software means is a windowing software means.

18. Apparatus according to any one of claims 1 - 15 in which the image combining means comprises hardware means.

19. Apparatus according to any one of the preceding claims in which the display means is a cathode ray tube display means, a liquid crystal display means, a digital light processing display means, a plasma display panel display means, a liquid emitting diode display means, or an organic light emitting diode display means.

20. Apparatus according to any one of the preceding claims in which the display means is a front or rear projected display means.

21. Apparatus according to any one of the preceding claims in which the display means is a single channel display means.

22. Apparatus according to any one of claims 1 - 20 in which the display means is a multi-channel display means.

23. Apparatus according to any one of the preceding claims in which the control means controls the liquid crystal shutter glasses to be synchronous with the frame rate of the primary image data source.

24. Apparatus according to any one of claims 1 - 22 in which the control means controls the liquid crystal shutter glasses to be synchronous with the frame rate of the secondary image data source.