A patent application filed by Sony and recently published on the United States Patent & Trademark Office’s website shows that the company is interested in technology that would allow for an autostereoscopic display that adjusts itself according to a user’s distance from the screen in order to provide optimal viewing from any position.
In simple terms, stereoscopic 3D works by sending two separate images to the viewer, one for each eye. The viewer’s left eye sees one image, and their right eye sees the other, slightly different image. When they look at the screen, they see one complete image that appears to have depth.
The problem with this is that autostereoscopic (glasses-free) 3D, such as what’s found on the 3DS, depends highly on the viewer’s angle and distance from the screen. Anyone who has used Nintendo’s handheld has probably seen the effects of viewing from a slightly-off angle or from too close/too far. It looks like a mess.
The technology in the patent application would be able to detect a user’s distance from the screen and adjust the separation of the two images accordingly. This would keep viewing optimal and avoid problems with blurring or compromising the 3D effect.
The illustrations also seem to indicate that the picture on the screen could adjust to viewing angles
Below is a description of how it works, according to the patent application:
In an example embodiment of the present invention, an entertainment device such as a Sony.RTM. Playstation 3.RTM. device reproduces pre-recorded stereoscopic video for a stereoscopic television. The stereoscopic video comprises left-eye and right-eye images whose separate points of view give rise to displacements between corresponding image elements of these images, which in turn gives rise to apparent depth in the resulting stereoscopic image when viewed by a user. The separation in apparent depth between different image elements is a consequence of the different displacements between different pairs of corresponding image elements and hence is also a function of the size of the screen and the distance of the viewer from the screen, both of which serve to scale the perceived displacements. Hence for a given size of screen there is an ideal distance for the viewer at which the displacements and hence relative depth of image elements are correct. However, when the viewer is sat, for example, too far from the screen, it is impractical to compensate for this by increasing the size of the screen. Consequently in the example embodiment the entertainment device, having the size of the television screen and a measure of the viewer’s distance, or alternatively having performed a calibration process, re-composes the stereoscopic image to generate new displacements between the corresponding image elements of the stereo image pair, thereby generating a new ideal distance from the screen that substantially coincides with the actual distance of the viewer. This is done by shifting image elements in at least one of the left-eye and right-eye images to change the size of displacements, as a function of the existing displacements, and hence the point of intersection of lines of sight between the corresponding image elements and the viewer, so that the separation in depth between different image elements is substantially the same as it would have been if the user had been viewing the original stereoscopic video at the original ideal distance.
As with all patent applications, this doesn’t mean we will see such a product, but it does show that the tech is important enough for Sony to seek a patent on it.
We’ve contacted Sony for a comment on the patent application and will update accordingly if we hear back.