Brother Industries, Ltd. (president: Toshikazu Koike) has announced that it has successfully developed a prototype spectacle-type wearable retinal imaging display(RID), which is significantly smaller than the previous prototype. Brother is actively developing technologies for retinal imaging displays, such as creating an attraction for EXPO 2005 Aichi, Japan whereby visitors could view images through a head-mounted RID.




RID is an image projection technology that focuses light, of an intensity harmless to the eyes, onto the retina and then moves the light at high speed to create afterimages. Images projected onto the retina appear as if they existed in front of the user.

Features of Brother's RID
1.   The transparent display enables users to see RID images placed in the visual field.
2.   Users can view private images and confidential data away from being viewed by others.
3.   Even though the product is a small, spectacle-type wearable display, the images appear as if on a virtual large screen.

Schematic illustration of the RID



Technical details

1.   Significant reduction in size and weight: less than one thousandth of the previous prototype

Our RID consists of three modules: a light source module, an optical scanning module, and an eyepiece module. This prototype uses an optical micro electro mechanical system (MEMS) scanner based on our new optical scanning module technology and a smaller eyepiece module to reduce the size and weight to less than one thousandth of the previous prototype.

Configuration of the RID



2.   Development of small optical scanning and eyepiece modules

Since starting to sell laser printers in 1987, Brother has developed various optical systems and laser printing technologies. To reduce the size of optical scanning and eyepiece modules for the new prototype, the company developed an optical scanning module technology to combine a high-speed and a low-speed optical MEMS scanner, and also a smaller eyepiece module with an aspheric lens.
These innovations have significantly reduced the size of the product.
Brother will continue to develop wearable RID devices with even smaller light source modules.


3.   Optical MEMS scanner with world-class operating frequency

Based on its inkjet printing technology, Brother has been developing piezoelectric MEMS technologies and proprietary thin-film actuators. By using these technologies, the company has successfully developed in-house an optical MEMS scanner (high-speed scanning mirror device), with world-class operating frequency, to create clear images.

Outline of the RID specifications (Except Cable & Spectacle Frame)
Resolution Frame rate Angle of view Size Weight	: SVGA (800 x 600) : Approx.60Hz : Approx. 20ox15o : Approx. 20 cc : Approx. 25g

Outline of the optical MEMS scanner specifications
Drive system Mirror diameter Optical resonant angle Operating frequency Dimensions	: Piezoelectric resonant drive : Approx. φ1 mm : Approx. 20o : Approx. 30 kHz : Approx. 12x8x2mm (LxWxT)	Enlarged photo

 Conceptual image of the visual field seen through the RID



 Conceptual application of the RID

Ability to maintain a server and check manual simultaneously, hands-free

No more worries about confidential information being viewed by others Enlarged display for small-screen mobile devices