Patent Application
20160170223
1. Field of the Invention
The invention generally relates to stereoscopic viewing, and more particularly to method and apparatus for stereoscopic viewing.
2. Related Art
Many optical devices, use biocular viewing, or, viewing using both the left eye and the right eye simultaneously, for eye comfort and enhancing the experience of the viewer. Binocular devices, such as portable binocular telescopes, popularly called binoculars, are designed to provide biocular viewing, i.e., simultaneous viewing for the left and the right eye. For monocular devices like telescopes or microscopes with single objective lens(es) and/or mirror(s), biocular attachments use mirrored or duplicated images to provide biocular viewing for the left eye and the right eye.
When viewing objects that are at great distances, the light entering in both eyes (left eye and right eye) of a viewer through the left and right eyepieces, respectively, is identical or nearly identical. In such a scenario, also described as a scenario in which the object lies at ‘infinity’, the eyes do not perceive the depth dimension of the object being viewed, or the depth with respect to the object's surroundings, and instead perceive a two dimensional image of the object, as illustrated in
Similarly, an object drawn or printed on a planar surface appears as a two-dimensional object, or an object having very low depth may appear as a two-dimensional object, if the depth of the object is too low. In such cases, the viewer cannot perceive the depth of such an object because the depth is too low, even though the object itself may be relatively nearby.
Viewing objects in three dimensions, that is, the ability to perceive depth of an object is more preferable and attractive compared to viewing an object in two dimensions, when the depth of the object is not perceived. Accordingly, there exists a need for method and apparatus for stereoscopic viewing.
According to an embodiment, a stereoscopic viewing apparatus comprises a left eyepiece corresponding to a left light path for viewing by a left eye, and right eyepiece corresponding to a right eye path for viewing by a right eye. The at least one light-shifting device is positioned in at least one of the left light path or the right light path, wherein the at least one light-shifting device displaces light incident on at least one of the left eye or the right eye.
According to an embodiment, a method of retrofitting a biocular optical device with a stereoscopic viewing apparatus comprises positioning at least one light-shifting device in at least one of a left light path or a right light path corresponding to a left eyepiece or a right eyepiece, respectively. The at least one light-shifting device displaces light passing through at least one of the left eyepiece or the right eyepiece.
The accompanying drawings incorporated herein form a part of this specification, and illustrate the embodiments described herein. The drawings are merely illustrative and not intended to limit the embodiments described herein.
Embodiments of the invention provide method and apparatus for stereoscopic viewing, and more specifically, creating a perception of depth or a three-dimensional view in scenarios in which only a two-dimensional view of an object of interest has been conventionally possible. Embodiments described herein utilize the theory, known to those familiar with the art of depth perception, that the difference in position of objects within a field of view perceived by a left eye and a right eye of a viewer, is used by the viewer's brain to create a perception of depth, resulting in the perception of three-dimensions. The difference in position of objects is substantially in a horizontal direction, and the quantum of the difference in the position depends on several factors including the depth of the object, type of optical devices, a viewer's eye and brain biology, among other factors. However, the embodiments described herein are not limited by such theory of either the brain's processing of images to create the perception of three-dimensions, or the optics of optical devices such as telescopes, handheld binoculars, microscopes and the like.
Specifically, the inventor has conceived of techniques and apparatuses to simulate a three-dimensional effect when viewing an object, especially in situations in which only a two-dimensional image of the object is commonly made possible by various optical devices. The scenarios where only two-dimensional viewing is commonly available are where an object is very far from the viewing device (also referred to as the object being at infinity focus), or when viewing a two-dimensional object, such as an image on a surface, or an object on a microscope slide, among several other similar situations, where the eyes or the brain of a user cannot perceive the depth of the object. The depth of an object also includes the dimension of the object along the general direction of the light coming from the object to an optical device using which the object is being viewed.
The embodiments of the invention shift at least a portion of the light incident on at least one of the eyepieces horizontally, that is, to the left or the right of a viewer's eyes, such that the images formed in the left eye and the right eye of the viewer are slightly different. Shifting a portion of the light incident on an eyepiece, that is, within the eyepiece's field of view, shifts the part of image corresponding to the shifted light portion horizontally, resulting in a modified field of view corresponding to the eyepiece. The light incident on the light-shifting device is shifted or displaced with respect to the path the incident light would have taken in the absence of the light-shifting device. Generally, the shifting or displacement of light does not relate to a change in focus of the optical device, although a composite light-shifting device and an objective optical component, such as a composite lens, can be incorporated in the optical device within the scope and spirt defined by the embodiments described herein. Thus, by shifting one or more portions of the light incident only on one eyepiece view, or shifting one or more portions of light incident on each of the eyepieces in horizontal directions, slightly different images corresponding to each of the two eyepieces' field of view, are formed in the corresponding two eyes. The difference in the images of the left eye and the right eye creates a perception of depth for the object being viewed, for example, the object corresponding to the portion of light shifted, which creates a spectacular enhancement in the visual quality of the object, as compared to the images formed without utilizing the embodiments herein.
Embodiments described herein are applicable to biocular viewing, that is, for viewing by both the left and the right eye simultaneously, such that the two eyes perceive at least a slight difference in the images formed in the respective eyes. Viewing images in the left and the right eye simultaneously is referred to as stereoscopic viewing, which may include viewing different images in each of the two eyes. Incorporating a biocular attachment for two-eye viewing in single objective optical devices is well known. Further, inserting additional optical modification devices in biocular devices, such as single objective optical devices having biocular attachments, or dual objective optical devices, such as binoculars, is generally well known. Embodiments of the invention may readily be incorporated in such biocular devices, by inserting light-shifting device(s) at desired positions in the light path of such biocular device, using known techniques. In some embodiments, the light-shifting device(s) are configured to be removable from the light path, and specifically, are removable and reinsertable by a viewer using the biocular device, which is achieved, for example by mounting the light-shifting device(s) on a removable and reinsertable platform, such as sliding carriers well known in the art. As an example, US Patent Application Number 2005/0254125, titled “Telescope power switch,” incorporated herein by reference in its entirety, describes sliding carriers 34, 35 which may carry, instead of a lens, a clear optical flat having the light-shifting device(s) mounted thereon, such that the light-shifting device(s) may be removed and reinserted from the light path of an eyepiece or its field of view, by a viewer. Such sliding carriers may be inserted in single objective devices such as telescopes, in either or both channels of the biocular attachments to single objective devices, or in either channels of dual objective devices, such as binoculars, among several other optical devices and configurations thereof, which will occur to those skilled in the art within the scope and spirit of the embodiments described herein.
For example, as shown in
Apart from the conventional and known optics relating to magnification of objects being viewed, the optical device 200 comprises two eyepieces, a left eyepiece 220 and a right eyepiece 222, corresponding to a left eye 230 and a right eye 232, respectively. The light-shifting device 260 is affixed to the left eyepiece 220 using an adhesive 261. In general, the light rays may be modified (i.e. shifted or displaced) by the adhesive 261 as well, unless the adhesive 261 has a negligible refractive index or a shape that does not cause shifting of the light (e.g. a cuboid having parallel entry and exit surfaces to the incident light). For the general discussion herein, the adhesive 261 is therefore included in the light-shifting device 260, unless otherwise mentioned or apparent from the context. Light rays 212, 214 from the object 210 are processed by the optics of the optical device 200, and resultant light rays 240, 242 respectively, are directed through the eyepieces 220, 222 to the eyes 230, 232. Specifically, a portion of light rays 212 along the left light path 215 are shifted (or displaced) horizontally by the light-shifting device 260 to a shifted left light path 216 to result in light rays 240, while the light rays 214 stay unmodified (i.e., not shifted) and along the right light path 218 to result in light rays 242. The modified left light path 216 is modified from the original left light path 215 by a shift angle 217. Therefore, a portion of an area within the field of view of the left eyepiece 220 is shifted by the light-shifting device 260 horizontally, while other areas in field of view of the left eyepiece 220 are not affected. For brevity of illustration, light rays 212 and 214 pertain to the object 210 only, and the light rays from the surrounding of the object 210 are not shown.
For example, as shown in
It is theorized that the shifted images 251 and 252 are combined by a viewer's brain to create a three-dimensional representation image 254, which may likely be a result of the brain extrapolating or interpolating information that does not necessarily exist in the image, although such theorization is not intended to limit the present embodiments. However, the resultant image 254 generally appears better, for example, the object 210 in focus stands out in comparison to its surroundings, eyes may therefore focus better on such an object and glean off more details than in a case where the object 210 does not stand out, for example, in the absence of the embodiments described herein. As another example (not shown), an object, such as a bird located far away (i.e., at infinity) from an optical device, such as handheld binoculars having two telescope channels objectives corresponding to each eye, processes light along each light path corresponding to the left eye 230 and the right eye 232 in an identical fashion, except that portion of the image processed through the light-shifting device 260 corresponding to the left eye 230 is shifted horizontally by a desired amount compared to the same portion of the image in the right eye 232. The resultant image would appear three-dimensional in the sense described above, with respect to the position of the image shifted in the left eye 230 but not shifted in the right eye 232, because the two different channels of the handheld binoculars would produce slightly different images, the difference pertaining to the area affected by the light-shifting device 260, in the eyes 230, 232. Slightly shifted images in the eyes result in an image that provide a perception of the depth of the bird's surroundings with respect to the bird, and therefore, the bird will seem to ‘jump out’ as compared to the surroundings of the bird, or in other words, appear three-dimensional.
While “three-dimensional” may not be an accurate description of the observed phenomenon, the observed phenomenon does create an effect that is similar to viewing a three-dimensional image, and all references herein to a three-dimensional image or view, are made accordingly. A single channel telescope or a single objective telescope coupled to a biocular viewing attachment, a binocular having two channels or dual objective telescopes, can both benefit from the embodiments of the invention by incorporating the stereoscopic viewing device described herein, among several other optical devices having two viewing channels corresponding to the left eye and the right eye, as known in the art.
The objects or region modified by the light-shifting devices 502-208 are perceived as being ‘farther away’ from the viewer, while the objects or region modified by the light-shifting device 510 ‘jump out’ at the viewer, creating an even more enhanced viewing experience of the object in the center of the eyepiece. The illustrated configuration of the light-shifting device 500 enhances the perceived distinction between the region corresponding to the center of the eyepiece 520 and the region corresponding to the periphery of the eyepiece 520. Different objects in a single image can be shifted differently by configuring the individual light-shifting devices 502-510 appropriately for example, by varying shapes, refractive indices, colors of the light-shifting devices, and the like, and several such configurations will occur readily to those skilled in the art according to the intended application of an optical device, without departing from the scope and spirit of the embodiments described herein.
In some embodiments, the eyepiece 520 may be a single lens or a composite eyepiece formed of several lenses as generally known in the art, and the various light-shifting devices 502-510 may be affixed to one lens of the eyepiece 520, or affixed in a distribution to multiple lenses of the eyepiece 520. Hereon, reference will be made to the eyepiece 520 and the lens(es) therein by the same reference numeral, unless indicated otherwise. In an embodiment, the light-shifting device(s) may be affixed to a platform other than the eyepiece 520, for example, an optical flat window located at an optimal position in relation to the eyepiece's 520 focal plane, on either the object side of eyepiece 520 or in an optical position with respect to the exit pupil facing the eye of the eyepiece 520.
Further, it has been observed that shifting light to right in the right eyepiece's field of view brings the image portion corresponding to the light displaced toward the outside of the field of view of the right eyepiece. This shifting or displacement toward the outside of the field of view makes the corresponding image portion appear to be farther away compared to the portions of the image that are not shifted or displaced. Further, shifting a portion of an image to the right in the left eyepiece's field of view brings such an image portion closer toward the center of the field of view of the left eyepiece, causing the image portion to appear to be closer to the portions of the image that are not shifted or displaced. The same effect is observed in combined fields of view of the left and the right eyepieces, wherein the portions of the image are displaced by light-shifting devices in either the left light path or the right ye path or both.
Accordingly, stereoscopic effect can be created in desired patterns by configuring the shape and position of the light-shifting devices. Similar stereoscopic effect can also be created by affixing a light-shifting device to the eyepiece using an adhesive with the same refractive index as the light-shifting device, in effect ‘blanking out’ the light-shifting properties of the light-shifting device where the adhesive is present. Specifically, in light-shifting devices such as a prism, the adhesive having the same refractive index as the prism can be used to form a shape complementing the shape of the prism, to form a resulting shape (e.g. a cuboid) which does not shift or displace incident light. In another embodiment where the adhesive has a refractive index different from the refractive index of the prism, then the combination of the prism and adhesive will still shift or displace incident light.
Further, light-shifting devices can be affixed to a platform or lenses that are a part of an eyepiece, or on platforms that are not a part of an eyepiece, for example, as illustrated by
Table 1 illustrates for retrofitting any biocular optical device with a stereoscopic viewing apparatus, according to embodiments of the invention.
According to some embodiments, the eyepieces include at least one of a convex lens, a concave lens, an Erfler eyepiece, a Konig eyepiece, an orthoscopic eyepiece, a Kelner Eyepiece, a Plossl eyepiece, or Naglers eyepiece. According to some embodiments, light shifting device comprises at least one of a prism, a Fresnel prism, a lenticular array, a wedge prism, or an optical window having a portion of different refractive index compared to the rest of the optical window. According to some embodiments, the light-shifting device(s), in one or both eyes, are configured to shift or displace light by about 0.1 degrees to about 20 degrees horizontally. In some embodiments, the light is shifted or displaced by about 1.5 degrees to about 2.5 degrees horizontally. In some embodiments, the light is shifted or displaced by about 2 degrees horizontally. As used herein, shifting or displacing light refers to displacement of the portion of image corresponding to shifted or displaced light.
As used herein, “biocular” includes two viewing channels, and includes dual objective optical devices such as binoculars, and biocular viewing attachments coupled with single objective optical devices such as a telescope. Optics of an optical device refer to various optical apparatuses for creating desired magnification and light paths, for example, in a telescope, the lenses and mirrors. Further, stereoscopic dual objective optical device comprises handheld binoculars, mounted binoculars, dual tube telescopes, Newtonian binocular telescopes, or low power Huygenean binoculars, among several other optical devices known in the art.
In the optical art, objects that are too far away are generally referred to being at infinity, and the optics of the optical device is configured for infinity focus to view such devices. Light rays from such objects are illustrated by generally parallel rays, which is a matter of representation, and is not intended to limit the embodiments described herein. Drawings illustrate simplified light ray diagrams for brevity. The light rays, for example, shown in
Embodiments of the invention don't create an actual three-dimensional image of an object(s) being viewed, rather, the embodiments generate a perception of three-dimensions by shifting light in manner consistent with how the brain is theorized to experience depth perception.
Modifications to incorporate the embodiments described herein will occur readily to this skilled in the art, for example, application of the light-shifting devices to various optical devices to generate a stereoscopic view. While the present invention has been disclosed with reference to certain embodiments and variations, numerous other modifications, alterations and changes to the described embodiments are possible without departing from the sphere and scope of the present invention.
Accordingly, it is intended that the present invention not be limited to the described embodiments, but that it has the full scope defined by the above language, as shown in the figures, and as described in the claims which follow, as well as equivalents thereof.
This application claims the benefit of U.S. Provisional Application No. 62/124,210, filed Dec. 12, 2014.
| Number | Date | Country | |
|---|---|---|---|
| 62124210 | Dec 2014 | US |
