Tomohiko Hattori

Spatial modulation display using spatial light modulators

A spatial modulation display is described that permits the observation of a phantom or transparent image by several persons simultaneously and is suitable for medical imaging. The display uses spatial light modulators and large format convex lenses within a Schlieren optical system. The number of sectional images in a three-dimensional image is limited by the number of spatial light modulators. The display is electro-optical and requires no moving parts.

Stereoscopic liquid crystal display II (practical application)

Three-dimensional displays that permit simultaneous observation by plural persons have been reported in other papers, but a 3-D endoscope is only available for stereo image and is better used in the no-glasses method. Hence conventional 3-D techniques were poor for the endoscope for medicine. We produced a new 3-D device (stereoscopic liquid crystal display) which permits simultaneous observation of a stereo pair by plural persons without glasses and we improve the device for the endoscope. We combined the 3-D endoscope and the new 3-D device. The endoscope has two CCD cameras. The cameras create a stereo pair transmitted by two NTSC signals. The system is time-parallel stereoscopic.

Electro-optical autostereoscopic displays using large cylindrical lenses

An autostereoscopic system is described which permits the observation of a high-resolution image by several persons simultaneously and is suited to mass production. The display uses cylindrical lenses positioned in front of an image output screen. The number of lenses, or the parallax number, determines the number of simultaneous images which can be used to produce a look-around capability. The playback system uses an electro-optical vertical slit which oscillates horizontally within a large horizontal convex cylindrical lens. The resolution of the method is excellent and the parallax number can be varied. Using the transmission band width of HDTV, a five parallax color system with the standard television resolution can be produced.

Three-dimensional image display without special eyeglasses: observation of magnetic resonance angiography using the stereoscopic liquid crystal display.

The authors have developed a new stereoscopic liquid crystal display that provides real-time 3-dimensional image viewing without special eyeglasses. The device consists of 3 major parts: (1) an image display composed of a 10.4-inch color liquid crystal plate with a resolution of 640 x 480, (2) an automatic head tracking system, and (3) a special backlight unit for the right and left eyes. Eight radiologists interpreted 60 cases of magnetic resonance angiography (29 cases of cerebrovascular disease and 31 normal cases) to compare film display and the liquid crystal display (ie, pseudo 3-dimensional display and true 3-dimensional display). Using a continuously distributed scale ranging from 0% to 100%, the observers ranked their confidence levels in determining the presence or absence of steno-occlusive disease, aneurysm, and arteriovenous malformation (AVM) and their locations. For statistical evaluation, receiver operating characteristic (ROC) analysis and Brier score were used. For detecting AVM, film reading showed a significantly higher value in the area under the binormal ROC curve (Az) than did pseudo-3-dimensional display (P < .05). Excluding this, however, no significant difference existed in Az values among the 3 viewing methods. Also, there was no significant difference in Brier score between not only the stereoscopic view and nonstereoscopic view groups, but also the senior and junior groups. Subjective estimation of true 3-dimensional display showed that vessels were more distinguishable with less eye fatigue compared with stereoscopic film reading. The stereoscopic liquid crystal display provided almost equal efficacy to film reading; however, the short optimum distance for observation and the low resolution should be improved.

New color anaglyph method

Anagliphs generally means a stereoscopic method using 2 principal color filters and is impossible to perceive the full-color stereo-pair for the viewers as above. A new anagliph method using 3 principal color filters (RGB) is presented in this paper. The method enables the complete full- color stereoscopic image taking and output technique. We produced the prototype system which composed of an ordinal TV camera with RGB color optical filters positioned at the pupil or the iris as a function of a single lens stereoscopic image taking device and using a special electrical circuit for a stereoscopic image output devices. Time-parallel full-color stereo pair was delivered to the several viewers by a prototype system with an ordinal our stereoscopic liquid crystal display (STEREVIQ) which permits the observation of a stereo pair by several persons simultaneously without the use of special glasses. Especially the systems cost performance is excellent except STEREVIQ.