GB2428102A

GB2428102A - Viewing device

Info

Publication number: GB2428102A
Application number: GB0513838A
Authority: GB
Inventors: David Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-07-06
Filing date: 2005-07-06
Publication date: 2007-01-17
Also published as: GB0513838D0

Abstract

A viewing device, preferably stereoscopic, that has two viewing modes and can switch or transition between these two modes. In viewing mode 1, the user sees a view of the real world (1) which may have a synthetic alignment line overlaid or superimposed on to this view. In viewing mode 2, the user sees a synthetic image and the synthetic alignment line may or may not be visible. When visible, the synthetic image and the view of the real world appear in the same position relative to the user's eye and are of the same dimensions. The device may be used view the same site at different times, for example the synthetic image may relate to buildings at an archaeological site or buildings at a construction site, providing the viewer with images of the site at the present time and site as it may appear at past/future times.

Description

VIEWING DEVICE

FIELD OF THE INVENTION

This invention relates to viewing devices for use by an individual or several people when they are visiting a building, location or place of interest.

BACKGROUND OF THE INVENTION

A building, location or place of interest (hereafter referred to as a site) can change appearance over time. When at a site, such as an historic site, it can be difficult to imagine how it appeared in the past. Similarly, when at a site, such as a building site, it can be difficult to imagine how it will appear in the future.

Helping visitors at historic sites to imagine how the site appeared in the past has been the subject of two experiments funded by the EC since 1999 at the historic sites Olympus (Project Reference: IST-l999-1l306) and Pompeii (Project Reference: IST- 2001-34545) . Both used experimental augmented reality systems including head mounted displays that enabled visitors to have their view of the real site augmented with a synthetic full-motion recreation of how the site looked in history and thus, enabling the visitors to imagine how the site originally appeared. These augmented reality systems proved too expensive for the historic site industry and following the completion of the experiments, no installations at historic sites were made or planned to be made.

Electronic augmented reality systems are an established technology. Patent number US2002118273 (application number US1990269302, 19990329) describes an augmented reality system that combines a stereoscopic synthetic image with the view of a real object. The system can calculate the angle and orientation (hereafter called viewpoint) of the user's view of the real object and so create and project the synthetic image as if viewed from the same viewpoint. Thus, the view of the real object and the synthetic image align.

The problem with this system is that it uses electronic displays such as an LCD or a head-up display system.

Electronic displays make the system too expensive for wide spread use by visitors at, for example, historic sites and building sites.

A further problem with the above system is that it uses electronics to calculate the viewpoint of the user's view and at which to project the synthetic image in real time.

Using electronics to make this real time calculation makes the system too expensive for wide spread use by visitors at, for example, historic sites and building sites.

Optical mechanical stereoscopics are also an established technology. Patent numbers 13S3632186, JP59140419 and FR2755251 all describe optical mechanical stereoscopic viewing devices in which synthetic images can be viewed. The problem with these systems is that they do not enable the user to see the real world while using the system.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a comparatively lowcost and affordable viewing device for many applications such as historic sites and building sites.

The viewing device of the present invention enables both a view of the real world and a view of a synthetic image to be seen separately, in their entirety, or simultaneously, in part, wherein the viewing device and the view of the real world and the view of a synthetic image are aligned by manual and optical mechanical means.

This disclosure describes an invention that uses an optical mechanical system, preferably stereoscopic, to align and then to switch or transition between a view of a real site and a synthetic image, where the synthetic image depicts a view of the site that appears to be from the same angle and orientation as the view of the real site. The view depicted in the synthetic image is of how the site appeared in the past or will appear in the future. Thus, as this invention switches or transitions from the real site to the synthetic image, it enables the user to more easily imagine how the site appeared in the past or will appear in the future from the viewpoint of the user.

The difference in appearance between the real site and the synthetic image will be more easily noticed by the user as elements common to both the real site and the synthetic image will appear unchanged during the transition between the two as these elements will be seen at the same angle and in the same place in both views. The system disclosed herein can be used in any situation with a need to compare or transition between a view of the real world and a synthetic image. Examples include historic sites where visitors may need to compare a real view of remains and a synthetic image recreating the site as it originally appeared in the past, cities where visitors may need to compare a real view of the city today and a synthetic image recreating how the city appeared in the past, building sites where architects and their clients may need to compare a real view of the site today with a synthetic image recreating how the site will appear when construction is completed.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail with reference to one embodiment illustrated in the drawings, wherein; Figure 1 shows a plan view of an embodiment according to the present invention and; Figure 2 shows an alternative plan view according to the present invention.

DETAILED DESCRIPTION OF THE 1NVENTION

The viewing device of the present invention comprises an optical mechanical system, preferably stereoscopic, and several synthetic, still portrayals, slides or images that are able to be made visible and not visible to the user (hereafter referred to as synthetic images) and several synthetic lines contained on, for example, slides or reflective surfaces, that are able to be made visible and may or may not be able to be made not visible to the user (hereafter referred to as alignment lines) . Each synthetic image contained in the device depicts the site differing in appearance to the real site, for example, depicting how the site appeared in the past or will appear in the future. The view of the site depicted in each synthetic image is from a specific viewpoint with respect to the site that the user can adopt, for example, a viewpoint will be at a specific height, such as the average eye-level height of men, vertically above a specific point on the ground at a site.

This specific viewpoint is hereafter referred to as the critical viewpoint. For each synthetic image, the device also contains a corresponding alignment line. The alignment line is in a shape that corresponds to certain features visible at the real site when seen from the critical viewpoint.

The device has two viewing modes and can switch or transition between these two modes. In viewing mode 1, the user sees the real site within the device with the alignment line overlaid or superimposed on to this view. The synthetic image is not visible. In viewing mode 2, the user sees the synthetic image in its entirety, the real world is not visible and the alignment line may or may not be visible.

When visible, the synthetic image and the view of the real site appear in the same position relative to the user's eye and are of the same dimensions. The positions where the synthetic image appears, the view of the real site appears and the view of the alignment line appears, are fixed and do not move relative to the user's eye and relative to each other. Thus, the position, and appearance of the synthetic image, when visible in its entirety, cannot be changed.

Similarly, the position, and appearance of the alignment line, when visible in its entirety, cannot be changed.

However, whilst the position of the view of the real site, when visible in its entirety, cannot be changed, the appearance of the site can be changed simply by the user changing their viewpoint in relation to the site.

The user uses the device at the geographical location of the critical viewpoint. This location is identified to the user, for example, by being marked on the ground. The user looks through the device in viewing mode 1 and sees the real site S with the alignment line overlaid or superimposed on to this view. As the position of the alignment line is fixed relative to the user's eye, the user must adjust his or her viewpoint to align the alignment line with the features at the real site seen by the user through the viewing device.

When the user has aligned the features in the real site and the synthetic line, the user has adopted the critical viewpoint. Thus, the view of the real site is now in alignment with the view of the site depicted in the synthetic image, when it is visible. This is so because the synthetic image and the alignment line depict the view from the critical viewpoint and the positions where the synthetic image and the alignment line appear are fixed relative to each other and the view of the real site.

The user now switches from viewing mode 1, the real site with alignment line, to viewing mode 2, the synthetic image.

The synthetic image appears substantially in the same position and of the same dimensions as that of the real site, relative to the user's eye. The switch or transition is made by means of a button or lever on the device that adjusts the optical mechanical system so as to change the view visible to the user's eye from the view of the real site and alignment line to the view of the synthetic image.

The switch or transition starts with the real view and alignment line wholly visible and the synthetic view not visible. At the end of the transition the synthetic view is wholly visible, the real view is not visible and the alignment line may or nay not be visible.

The switch or transition may take one of several forms, for example, the switch may be a gradual fade with the real view fading out and the synthetic image fading in, so that both views are visible or partially visible simultaneously during the transition. Another example form that the switch may take is a slow wipe vertically upwards, where the real view is seen to disappear below a horizontal line as the line moves vertically upwards from the bottom of the view to the top, as this happens the synthetic view appears below the horizontal line as it moves upwards so that both views are partially visible simultaneously during the transition.

There may be other forms of switch or transition between the two views. During the transition, the position of the synthetic image, and the features within it, as it appears to the user, remains fixed relative to the user's eye. Thus, in relation to the synthetic image, the transition makes the synthetic image visible to the user, in. part or whole, in it's fixed position and the transition does not move the synthetic image as the user sees it. This is similarly the case for the view of the real site, in that the transition makes the view of the real site not visible to the user, in part or whole, in its fixed position and the transition does not move the view of the real site as the user sees it.

Whatever form the transition takes, the transition can be made back to the real view and this will work in the same way as the original transition but in reverse. Thus, the user sees the real site from the critical viewpoint switched or transition to the synthetic image depicting the site rrom the critical viewpoint and differing in appearance to the real site.

The height of the critical viewpoint may be consistent for all the synthetic images and corresponding alignment lines contained in a single viewing device, for example, the height of 5 feet 6 inches. However, the height of the critical viewpoint may differ between different devices intended for use at the same site, for example, one device may use a height of 5 feet 6 inches, whereas another device may use a height of 3 feet 2 inches. By creating viewing devices for a site that differ by the height of the critical viewpoint, a user at a site is able to select the height that they can most easily adopt, and so the user will be able to experience their view of the real site transitioned to a synthetic image depicting the site from the same viewpoint.

The critical viewpoint for a synthetic image and corresponding alignment line has a defined geographical location and height. If copies of the same synthetic image and corresponding alignment line are contained in two different viewing devices, both devices will be for use at a single critical viewpoint. However, as only one device can be used at a tine at a single critical viewpoint, the user who arrives second at the geographical location will have to wait to use his device until the first user moves away. To overcome this, different viewing devices may contain synthetic images and corresponding alignment lines that have slightly different critical viewpoints, whilst depicting the site in a very similar way. For example, the different critical locations may be at the same height but be the width of a person apart, such that two users would be standing next to each other when using their devices. In this way, several users can use their devices in the same general area, at the same time to view similar depictions of a site and so reduce queuing. Where several critical viewpoints are located closely together, the different locations for each viewpoint will be marked on the ground with an identifying mark, such as a number. This identifying mark will also be contained on the corresponding viewing device and so will enable a user to know at which location to stand to be able to adopt the critical viewpoint for their viewing device.

One embodiment of this invention will now be described with reference to the accompanying drawings.

The user locates himself or herself at the geographical location of the critical viewpoint which is marked on the ground by, for example, an outline of a pair of footprints.

Other locating marks may also be used. The user stands on the locating marker and uses the viewing device in viewing mode 1 and sees a real building with an alignment line.

Figure 1 shows the optical system in viewing mode 1 to enable this for a single eye. The system may be replicated for a second eye to produce a stereoscopic viewing device, if desired. The user 8 looks through the eye lens 7 and sees a real view of building 1 combined with an alignment line on reflective mirror or other reflective surface 6. The image of building 1 is carried via light waves 2 (represented as arrowed lines through-out Figure 1) to lens ( or beam splitter 3, lens or beam splitter 3 deflects the light to the reflective mirror 4. Mirror cover 5 is in the open position enabling the light to reach reflective mirror 4, reflective mirror 4 reflects the light to viewing mirror 6, the surface of which contains an alignment line in, for example, the shape of the outline of building 1 when building 1 is viewed from the critical viewpoint. The alignment line may, for example, be a thin line made of a permanent, opaque, non-reflective coating material. The user adjusts his or her position so that the alignment line matches the outline of building 1. In this way, the user is able to see the real building 1 from the critical viewpoint defined by the alignment line. In this arrangement, the synthetic image on slide 11, that depicts building 1 when viewed from the critical viewpoint defined by the alignment line, is not reflected onto the viewing mirror 6 as reflective mirror 10 is covered by the mirror cover 9.

A mechanical system connecting mirror cover 5 and mirror cover 9 is used to transition between viewing mode 1, the real view of building 1 and viewing mode 2, the synthetic image on slide 11. The mechanical system makes mirror cover 9 cover reflective mirror 10 whilst enabling mirror cover 5 to not cover reflective mirror 4. When the system is switched, the system makes mirror cover 5 slide over to cover reflective mirror 4, whilst simultaneously making mirror cover 9 slide open so as to no longer cover reflective mirror 10. By switching this mechanical system, the user changes the optical system from the arrangement for viewing mode 1 shown in Figure 1 to the arrangement for viewing mode 2 shown in Figure 2, which enables the user 8 to see the synthetic image on slide 11. The image on slide 11 depicts building 1 when viewed from the critical viewpoint defined by the alignment line contained on viewing mirror 6. Light waves 2 (represented as arrowed lines throughout Figure 2), from natural light or a synthetic source such as a light bulb, behind slide 11, carry the image on slide 11 to reflective mirror 10, reflective mirror reflects the light to viewing mirror 6, the image on viewing mirror 6 is then visible to the user 8 through eye piece lens 7. The real view of building 1 is not reflected onto viewing mirror 6 as reflective mirror 4 is now covered by mirror cover 5.

The mechanical system performs the transition in a wipe vertically upwards. Before the start of the transition only the view of building 1 and the alignment line is visible to the user. As the transition starts and mirror cover 5 slides up, it will cover the bottom of reflective mirror 4 first and so the bottom of the view of building 1 will no longer be visible or will be less visible to the user across a horizontal line the width of mirror cover 5.

Simultaneously, mirror cover 9 slides up and uncovers the corresponding bottom of reflective mirror 10, which will reflect the bottom of the image on slide 11 on to viewing mirror 6 and so become visible to the user. Thus, the user sees the bottom of the image on slide 11 and the upper section of the view of building 1. As the transition continues and the mirror covers slide further, to cover and uncover their respective mirrors, the view of building 1 is seen by the user on viewing mirror 6 to disappear below a horizontal line as the line moves vertically upwards from the bottom of the view to the top, and simultaneously the image on slide 11 appears below the horizontal line as it moves up so that both building 1 and slide 11 are partially visible simultaneously during the transition. When the transition is complete, the image on slide 11 and the alignment line are visible to the user, building 1 is no longer visible.

It will be understood to the person skilled in the art that the transition may also be performed in a vertically downwards motion or horizontal motion or any other suitable motion, for example, diagonally.

Several slides may be contained in the viewing device to show different depictions of the site. The slides may be contained on a reel. When the reel is wound on to the next slide, that slide adopts the same position as slide 11, so that it can be viewed in the same way as slide 11.

Reflective mirror 6 is preferably a part of a rotatable drum of mirrors. Each mirror has a different alignment line on its surface that corresponds to a slide. The drum is preferably connected to the reel of slides in such a way that when the slide reel is wound on to the next slide, the drum of mirrors is rotated to the next mirror containing the corresponding alignment line. The site preferably has the geographical location of the critical viewpoint for each slide marked on the ground by a marker, for example, an outline of a pair of footprints. ( (

Claims

ClAIMS 1. An optical device having an input and an output area, comprising

means for vLewing images said viewing means being disposed at the output area of said optical device and defining an optical axis; a viewing element in optical alignment with said viewing means; light deflection means disposed at the input area of said optical device arranged to deflect light from a first image entering the input area away from the optical axis to a first reflecting element; said first reflecting element being located away from said optical axis and arranged to reflect the first image onto the viewing element when the device is in a first viewing mode; a second reflecting element arranged to reflect a synthetic second image onto the viewing element when the device is in a second viewing mode; and means for activating and deactivating the first and second reflecting elements to switch between viewing modes; wherein the first image is visible on the viewing element at the viewing means when the second reflecting element is inactive, and the second image is visible on the viewing element when the first reflecting element is inactive.
2. An optical device according to claim 1 in which the viewing element comprises alignment indicia which are visible in the first viewing mode.
3. An optical device according to claim 2, wherein the alignment indicia are applied to the viewing element.
4. An optical device according to any preceding claims, wherein the first and second off-axis reflecting elements each comprise a mirror cover, which is operable by the activating and deactivating means to cover or uncover the reflecting element.
5. An optical device according to claim 4, wherein the mirror covers are provided with connecting means such that when the first off-axis reflecting element is covered the second off-axis reflecting element is uncovered.
6. An optical device according to any one of the preceding claims, further comprising an off-axis image slide which projects a synthetic image onto the viewing element.
7. An optical device according to claim 6, wherein the image slide comprises a reel comprising a plurality of slides.
8. An. optical device according to any one of the preceding claims, comprising a plurality of viewing elements.
9. An optical device according to claim 8, wherein the plurality of viewing elements are provided on a reel or drum.
10. An optical device according to claim 9, wherein said reel or drum is rotatable.
11. An optical device according to any one of the preceding claims, wherein the viewing element(s) comprise(s) reflecting element(s)

I
12. An optical device according to claim 11, wherein the reflecting element Cs) comprise Cs) mirror(s).
13. A stereoscopic optical device comprising two optical devices according to any of claims 1 to 12.
14. A method of viewing associated images comprising the steps of viewing a first image at viewing means from the first image being deflected to a reflecting means onto a viewing element when the device is in a first viewing mode, and viewing an associated synthetic image at the viewing means when the device is switched to a secod viewing mode.
15. A method as claimed in claim 14, in which the first image is first aligned with alignment indicia before the synthetic image is viewed.
16. An optical device substantially as hereinbefore described with relevance to, and as shown in the accompanying drawings.
17. A method of viewing associated images substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

612873; KVC; KVC