We clarify the effective range of distance between the front and rear images of the depth-fused 3-D (DFD) visual illusion. The DFD visual illusion is perceived when two images with many edges in the front and rear frontal-parallel planes at different depths are overlapped from the viewpoint of an observer. We evaluated how the fusion of the DFD visual illusion depended on the difference in distance between the front and rear images when the distance between the two images was changed. Subjective tests clarified the cases where DFD can be applied.

A method to improve the reflection efficiency of holographic polymer dispersed liquid crystal (HPDLC) is proposed and its effectiveness is confirmed. Controlling the alignment of liquid crystal (LC) in tiny droplets of HPDLC can increase the refractive-index difference between the LC droplet layer and the polymer layer, causing the peak reflectance and reflective spectral width to expand. We observed experimentally that 96% of the light components excluding the scattering loss can be diffracted in a transmission HPDLC device by ordering the LC. In a reflection HPDLC, we found that reflection could be improved by ordering through an applied shear force. Our findings should lead to an improvement in the quality of reflective display devices.

Liquid crystal displays (LCDs) are suitable as elements underlying wearable and ubiquitous computing thanks to their low power consumption. A technique that uses less power to drive 1-pixel LCDs is proposed. It harvests the charges on the LCD and stores them in an external capacitor for reuse when the polarity changes. A simulation shows that the charge reduction depends on the ratio of the capacitance of the external capacitor to that of the LCD and can reach 50%. An experiment on a prototype demonstrates an almost 30% reduction with large 1-pixel LCDs. With a small 10 × 10mm2 LCD, the overhead of the micro-controller matches the reduction so no improvement could be measured. Though the technique requires longer time for polarity reversal, we confirm that it does not significantly degrade visual quality.

3D video contents depend on the shooting condition, which is camera positioning. Depth range control in the post-processing stage is not easy, but essential as the video from arbitrary camera positions must be generated. If light field information can be obtained, video from any viewpoint can be generated exactly and post-processing is possible. However, a light field has a huge amount of data, and capturing a light field is not easy. To compress data quantity, we proposed the visually equivalent light field (VELF), which uses the characteristics of human vision. Though a number of cameras are needed, VELF can be captured by a camera array. Since camera interpolation is made using linear blending, calculation is so simple that we can construct a ray distribution field of VELF by optical interpolation in the VELF3D display. It produces high image quality due to its high pixel usage efficiency. In this paper, we summarize the relationship between the characteristics of human vision, VELF and VELF3D display. We then propose a method to control the depth range for the observed image on the VELF3D display and discuss the effectiveness and limitations of displaying the processed image on the VELF3D display. Our method can be applied to other 3D displays. Since the calculation is just weighted averaging, it is suitable for real-time applications.