Design of crossed-mirror array to form floating 3D LED signs

Abstract

3D representation of digital signage improves its significance and rapid notification of important points. Our goal is to realize floating 3D LED signs. The problem is there is no sufficient device to form floating 3D images from LEDs. LED lamp size is around 1 cm including wiring and substrates. Such large pitch increases display size and sometimes spoils image quality. The purpose of this paper is to develop optical device to meet the three requirements and to demonstrate floating 3D arrays of LEDs. We analytically investigate image formation by a crossed mirror structure with aerial aperture, called CMA (crossed-mirror array). CMA contains dihedral corner reflectors at each aperture. After double reflection, light rays emitted from an LED will converge into the corresponding image point. We have fabricated CMA for 3D array of LEDs. One CMA unit contains 20 x 20 apertures that are located diagonally. Floating image of LEDs was formed in wide range of incident angle. The image size of focused beam agreed to the apparent aperture size. When LEDs were located three-dimensionally (LEDs in three depths), the focused distances were the same as the distance between the real LED and the CMA.

10‐1: Resolution Evaluation Using MTF for A High‐Definition Floating Display

“…There are a various floating displays [1][2][3][4]. In this paper, we introduce two typical floating displays in retro-reflective types, respectively.…”

Aerial 3D LED display by use of retroreflective sheeting

“…We designed and fabricated a CMA for LED panel. 13 The CMA was composed of a large apertures (4 mm × 4mm) in order to defocus the LED lamps. By using the CMA, we realized an aerial LED sign, as shown in Figure 4.…”

“…Therefore, lights emitted from a light source converge into its image that locates at the plane-symmetry position about the reflector array. We have fabricated a crossed-mirror array (CMA) for an LED panel with blurring function to interpolate between LED lamps, 13 which is suitable for public installations but requires some improvements for advertisements that are shown in Figure 1.…”

Resolution enhancement in retro-reflector based on aerial imaging using micro aperture arrays

“…DCRA effectively improves the image distortion problem [5][6][7][8][9]. The DCRA consists of two micro-mirror arrays, which reflect the light twice to achieve suspension imaging.…”