Brother Industries' Retinal Scanning Display Goes Portable

Oct 20, 2009
Takuya Otani, Nikkei Electronics
Brother Industries reduced the size and weight of the light source module.
Brother Industries reduced the size and weight of the light source module.
[Click to enlarge image]
The portability of the retinal scanning display was improved.
The portability of the retinal scanning display was improved.
[Click to enlarge image]
The light source module for the previous prototype
The light source module for the previous prototype
[Click to enlarge image]

Brother Industries Ltd drastically reduced the size and weight of the light source module for the glasses-type retinal scanning display that the company is developing.

The new module measures approximately 95 x 170 x 30mm and weighs about 350g. The volume and weight are 1/20 and 1/13, respectively, those of the previous prototype and were realized by employing laser diodes. The company claims its retinal scanning display is the world's first display that uses green laser diodes.

The previous prototype uses laser diodes for the red and blue colors, but it is mounted with a solid laser based on a nonlinear optical crystal for the green color (See related article). In other words, the green light is created from red light by SHG (second-harmonic generation). Therefore, its light source module is as large as a cardboard box and is not portable.

Also, Brother Industries replaced the AC-driven power supply with a battery-driven one to add portability to the display.

The company aims to commercialize the glasses-type retinal scanning display in fiscal 2010.

"We have finished the development of the basic technologies needed for commercialization," it said. "And we are going to refine the display as a product by improving its durability, safety and so forth."

Retinal scanning displays cast faint light on a retina and scan it at high speed. The user recognizes the residual image of the light as an image. In other words, they are projectors that use a retina as a screen.

Unlike normal head-mounted displays (HMD) such as those equipped with an LCD panel, retinal scanning displays do not block the user's field of view and superimpose an image on the actual view. Brother Industries unveiled its prototype for the first time at Expo 2005 Aichi Japan, and it drew much attention.