holo
Touchable Holography
∗
Takayuki Hoshi,
Masafumi Takahashi†
,
Kei Nakatsuma‡
,
Hiroyuki Shinoda§
The University of Tokyo
1
Introduction
Mid-air displays which project floating images in free space have been seen in SF movies for several decades [Rakkolainen 2007].
Recently, they are attracting a lot of attention as promising technologies in the field of digital signage and home TV, and many types of holographic displays are proposed and developed. You can see a virtual object as if it is really hovering in front of you. But that amazing experience is broken down the moment you reach for it, because you feel no sensation on your hand.
Our objective is adding tactile feedback to the hovering image in
3D free space. One of the biggest issues is how to provide tactile sensation. Although tactile sensation needs contact with objects by nature, the existence of a stimulator in the work space depresses the appearance of holographic images. Therefore some kind of remotecontrollable tactile sensation is needed. That is achieved by our original tactile display [Iwamoto et al. 2008]. The following paper explains the technologies employed for a “Touchable Holography.”
2
Principle
2.1
Holographic Display
We use “Holo [Provision 2009],” a holographic display which provides floating images from an LCD by utilizing a concave mirror.
The projected images float at 30 cm away from the display surface.
A user can get near to the image and try to touch it. Of course, his fingers pass through it with no tactile sensation.
2.2
Tactile Display
“Airborne Ultrasound Tactile Display [Iwamoto et al. 2008]” is a tactile display which provides tactile sensation onto the user’s hand.
It utilizes the nonlinear phenomenon of ultrasound; acoustic radiation pressure. When an object interrupts the propagation of ultrasound, a pressure field is exerted on the surface of the object. The acoustic radiation pressure P [Pa] is written as
P = αE
∗
Takayuki Hoshi,
Masafumi Takahashi†
,
Kei Nakatsuma‡
,
Hiroyuki Shinoda§
The University of Tokyo
1
Introduction
Mid-air displays which project floating images in free space have been seen in SF movies for several decades [Rakkolainen 2007].
Recently, they are attracting a lot of attention as promising technologies in the field of digital signage and home TV, and many types of holographic displays are proposed and developed. You can see a virtual object as if it is really hovering in front of you. But that amazing experience is broken down the moment you reach for it, because you feel no sensation on your hand.
Our objective is adding tactile feedback to the hovering image in
3D free space. One of the biggest issues is how to provide tactile sensation. Although tactile sensation needs contact with objects by nature, the existence of a stimulator in the work space depresses the appearance of holographic images. Therefore some kind of remotecontrollable tactile sensation is needed. That is achieved by our original tactile display [Iwamoto et al. 2008]. The following paper explains the technologies employed for a “Touchable Holography.”
2
Principle
2.1
Holographic Display
We use “Holo [Provision 2009],” a holographic display which provides floating images from an LCD by utilizing a concave mirror.
The projected images float at 30 cm away from the display surface.
A user can get near to the image and try to touch it. Of course, his fingers pass through it with no tactile sensation.
2.2
Tactile Display
“Airborne Ultrasound Tactile Display [Iwamoto et al. 2008]” is a tactile display which provides tactile sensation onto the user’s hand.
It utilizes the nonlinear phenomenon of ultrasound; acoustic radiation pressure. When an object interrupts the propagation of ultrasound, a pressure field is exerted on the surface of the object. The acoustic radiation pressure P [Pa] is written as
P = αE
References: I WAMOTO , T., TATEZONO , M., H OSHI , T., AND S HINODA , H. 2008. Airborne ultrasound tactile display. In International Conference on Computer Graphics and Interactive Techniques ACM SIGGRAPH 2008 New Tech Demos. P ROVISION, 2009. Holo. http://www.provision3dmedia.com/. R AKKOLAINEN , I. 2007. How feasible are star wars mid-air displays? In 11th International Conference Information Visualization, 935–942.