1. History of stereoscope
　Original stereoscope was invented by Wheatstone in United Kingdam in 1838. It gives stereoscopic vision by its separated stereo image pair (One picture for left eye and the other for right eye) and 2 mirrors as figure 1. And 1849, Brewster in UK invented prism stereoscope (figure 2) which uses prisms instead of mirrors. Afterwards a stereoscope with lens which replaced prisms became popular. Viewmaster represents this kind of stereoscopes and it has a lot of fans now. On the other hand, mirror-type stereoscope developed into 4-mirror system (figure 3) and it had used for appreciation of comparatively large stereo image pair.But new 3-D display methods was invented in the 20th century such as lenticular method, polarized filter method and shutter glasses method. In 1990 decade stereoscope became regarded as an antique toy.

2. stereoscope for monitor
　In 1990 decade, high-resolution and large and flat screen monitor became popular. Stereoscope attracted public attention again as device for monitor for stereoscopic vision. Then, 4-mirror stereoscope (figure 3) and prism stereoscope (figure 2) which suit large screen was sold for fans of stereo photographies.In the 21st century, digital stereo photographies and 3D computer graphics and 3D computer aided design became active. Authors and viewers of them rose a new demand for viewing a stereogram by a household monitor. But the past stereoscopes imposed some restrictions such as the limit of the monitor size or the position for appreciation or the distance between user's eyes etc.. Moreover, a high-quality panorama image was not able to be appreciated with the past stereoscopes. So the past stereoscopes couldn't satisfy their need.

3. twist-mirror
　In 1982, I invented the first liquid crystal 3D game machine (figure 4) in the world in Tomy industry (present TOMY COMPANY, LTD) and developed it as core member. Afterward, in 1998 I established this company and started research of 3D monitor and HMD(head mounted display). While studying them, I doubted the technological forecast that "3D monitor would replace 2D monitor". Because I guessed the majority of visual contents would stay 2D in the future. For this reason, I guessed stereoscopic display function would stay added value of a monitor. So our company focused on the development of a stereoscope for a monitor in 2005-06. As a result, I invented twist-mirror optical system (figure 5). Twist-mirror optical system can be led by changing Wheatstone's optical system consecutively. Then, erect mirror stereo pair changes inverted mirror stereo pair. This unique design which needs inverted mirror stereo pair solve the problems of the past stereoscopes for monitor at one effort.

4. for global company
　Until now, we have researched and developed 3D equipment in cooperation with another company. (we've only researched and developed it) Manufacturing sales of HOLOBLADE is the first business to which user's order is received. We feel challenge and tence in time. We continuously make an effort to make HOLOBLADE loved all over the world.

November, 2006 HIT DESIGN Ltd.
Kazumi Matsumoto