Controllable device for phase modulation of coherent light

Patent metadata

Field	Value
Publication number	US-10102814-B2
Application number	US-201214430259-A
Country	US
Kind code	B2
Filing date	Oct 1, 2012
Priority date	Oct 1, 2012
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A controllable device for phase modulation of coherent light comprises a modulator matrix having a plurality of liquid crystal modulator cells each being adapted to modulate a phase value of light passing through a liquid crystal modulator cell depending on a voltage, which is applied to the liquid crystal modulator cell; at least one polarity area of said modulator matrix including at least one liquid crystal modulator cell; at least one storage unit for storing at least one pair of voltage values of which one has a positive and the other has a negative polarity for the liquid crystal modulator cells, whereby the pair of voltage values corresponds to a predetermined phase value; and a control unit for selectively applying one pair of voltage values to one liquid crystal modulator cell.

First claim

The invention claimed is:

1. A controllable device for phase modulation of coherent light with a spatial light modulator device for generating a light distribution, comprising:
a modulator matrix having a plurality of liquid crystal modulator cells each being adapted to modulate a phase value of light passing through said liquid crystal modulator cell depending on a voltage, which is applied to said liquid crystal modulator cell;
at least one polarity area of said modulator matrix including at least one liquid crystal modulator cell;
at least one voltage value storage memory storing at least one pair of voltage values of which one has a positive and the other has a negative polarity for said liquid crystal modulator cells, whereby said pair of voltage values corresponds to a predetermined phase value; and
a voltage controller selectively applying one pair of voltage values to one liquid crystal modulator cell, whereby said voltage controller applies alternately said voltage values of positive or negative polarity according to an inversion scheme such that voltages applied to one polarity area have the same polarity;
whereby at least one of:
the size of the polarity areas is predetermined in advance according to a display type, in which the controllable device is included or;
the light distribution to be generated is defined by at least one sub-hologram and the voltage controller adjusts at least one of the polarity area size and a polarity area position and a polarity area shape such that the length of intersection lines between different polarity areas, in which one sub-hologram is generated, is minimized.

2. The controllable device according to claim 1 , whereby the voltage value storage memory stores pairs of voltage values for distinct phase values or for a predetermined phase interval with distinct phase values.

3. The controllable device according to claim 1 , whereby the voltage controller further dynamically adjusts at least one of said polarity area size and a polarity area position and/or a polarity area shape according to the light distribution to be generated.

4. The controllable device according to claim 1 , whereby the voltage controller further adjusts at least one of the polarity area size and a polarity area position and a polarity area shape such that one sub-hologram is generated within one single polarity area.

5. The controllable device according to claim 1 , whereby the voltage controller applies said pairs of voltage values to said liquid crystal modulator cells according to at least one of a line inversion scheme, a row inversion scheme, a dot inversion scheme, a chess-board inversion scheme, an arbitrary patterned inversion scheme and a frame inversion scheme for said polarity areas.

6. The controllable device according to claim 1 , whereby said one pair of voltage values for one phase value is predetermined in advance for a single liquid crystal modulator cell or one polarity area including a plurality of liquid crystal modulator cells in dependence on at least one of the polarity of the voltage value, the absolute value of the voltage, the size of the polarity area, the position of the liquid crystal modulator cell or the polarity area in the modulator matrix, and the time frame of the nominal phase value.

7. The controllable device according to claim 1 , comprising a plurality of voltage value storage memories selectively storing voltage values for at least one positive polarity, negative polarity, a liquid crystal modulator cell and a polarity area.

8. The controllable device according to claim 1 , further comprising an illumination unit for illuminating the spatial light modulator device with light, the illumination unit comprises a pulsed illumination or a predetermined illumination function, wherein the pulsed illumination or the predetermined illumination function of the illumination unit is synchronized with the operation of the spatial light modulator device or with the inversion scheme of the spatial light modulator device.

9. A display comprising a controllable device according to claim 1 , wherein the display is designed such that at least one of the following is presentable: two-dimensional image content and stereoscopic image content and/or stereoscopic multi-view image content and holographic image content.

10. A method for operating a controllable device according to claim 1 , whereby the voltage controller selectively applies one pair of voltage values to one liquid crystal modulator cell, whereby said voltage controller applies alternately said voltage values of positive or negative polarity according to an inversion scheme such that voltages applied to one polarity area have the same polarity.

Assignees

• Seereal Tech S A
• Sharp Kk

Inventors

• Missbach Robert
• Reichelt Stephan
• Leister Norbert
• Haussler Ralf
• Usukura Naru
• Katoh Hiromi
• Kanbayashi Yuichi

Classifications

• G03H1/2294

  Addressing the hologram to an active spatial light modulator · CPC title

• G09G3/3614 Primary

  Control of polarity reversal in general · CPC title

• G09G3/006

  Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays (testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309) · CPC title

• G03H2225/32

  Phase only · CPC title

• G09G2320/0214

  with crosstalk due to leakage current of pixel switch in active matrix panels · CPC title