Apparatus for deflecting light, device for scanning light, device for reading information and device for stereoscopic display

• US 20020060659A1
• Filed: 11/29/2001
• Published: 05/23/2002
• Est. Priority Date: 03/18/1994
• Status: Abandoned Application

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Ishimoto, Manabu, Nakashima, Masato, Matsuda, Takahiro, Sato, Noriko, Eguchi, Shin, Mizuno, Yoshihiro, Aritake, Hirokazu
• Application Number:
  US09/995,569
• Publication Number:
  US 20020060659A1
• Time in Patent Office: Days
• US Class Current: 345/94
• CPC Class Codes: G02B 30/34 Stereoscopes providing a stereoscopic pair of separated images corresponding to parallactically displaced views of the same object, e.g. 3D slide viewers
• CPC Class Codes: G02B 5/1828 having means for producing variable diffraction controlling the direction of light by means of one or more diffracting elements G02B26/0808; acousto-optical elements G02F1/11, G02F1/33; electro- or magneto-optical diffraction G02F1/292, G02F1/2955
• CPC Class Codes: G02F 1/292 by controlled diffraction or phased-array beam steering controlled diffraction for optical switching G02F1/31
• CPC Class Codes: G06K 2207/1015 Hologram
• CPC Class Codes: G06K 7/10594 Beam path
• CPC Class Codes: G06K 7/10663 using hologram

Abstract

An apparatus for deflecting light of the present invention comprises: (a) at least one pair of transference electrodes arranged facing one another; (b) a drive circuit which applies a voltage among the transference electrodes; and (c) a liquid crystal which is inserted among the transference electrodes, and whose parallel stripes that function as a diffraction grating when the voltage is applied among the transference electrodes are produced at a pitch corresponding to the applied voltage. The light can be scanned if a diffracted light by the apparatus for deflecting light is converted into a scanning light and a voltage value is changed temporally to apply the voltage among the transference electrodes. In a device for reading information, the scanning light is reflected in a bar code and the reflected light is detected by an apparatus for detecting light. In a device for stereoscopic display of the present invention, the apparatus for deflecting light is used as beam deflection means for deflecting the light beamed from a picture element which organizes the pictures of the picture display means.

Claims

1. An apparatus for deflecting light, comprising:

(a) at least one pair of transference electrodes arranged facing one another;

(b) a drive circuit which applies a voltage among the transference electrodes; and

(c) a liquid crystal which is inserted among the transference electrodes, and whose parallel stripes which function as a diffraction grating when the voltage is applied among the transference electrodes are produced at a pitch corresponding to the applied voltage.

2. An apparatus for deflecting light according to claim 1,

wherein an anisotropy of a permittivity of the liquid crystal is less than 0.

3. An apparatus for deflecting light according to claim 1,

wherein the drive circuit applies a voltage whose voltage value changes temporally among the transference electrodes.

4. A device for scanning light, comprising:

(a) an apparatus for deflecting light whose liquid crystal is inserted among the transference electrodes arranged facing one another, and parallel stripes which function as a diffraction grating when the voltage is applied to the transference electrodes are produced at a pitch corresponding to the applied voltage in the liquid crystal;

(b) a drive circuit which applies a voltage whose voltage value changes temporally among the transference electrodes of said apparatus for deflecting light;

(c) a light source which beams the light which will be injected into said apparatus for deflecting light.

5. A device for scanning light according to claim 4, further including:

an optical element for converging light installed on the incident light side or the outgoing light side of said apparatus for deflecting light.

6. A device for scanning light according to claim 4,

wherein an incident light angle of the incident light against the said apparatus for deflecting light is set almost equally to a Bragg angle of diffracted light used for the scanning light.

7. A device for scanning light according to claim 4, further including:

an optical element which is installed on the outgoing light side of said apparatus for deflecting light, and enlarges a deflection angle of the scanning light substantially.

8. A device for scanning light according to claim 4, further including:

an aperture installed between the light source and said apparatus for deflecting light.

9. A device for scanning light according to claim 4, further including:

a variable mechanism which makes a clearance along a light axile direction from the light source to the optical element for converging light variable.

10. A device for scanning light according to claim 4, further comprising:

(a) a half mirror which reflects an outgoing light of the optical element for converging light towards the direction alienated from the apparatus for deflecting light;

(b) a second optical element for converging light which converges the reflected light beamed from the half mirror;

(c) a reflecting member which reflects the outgoing light of the second optical element for converging light and lets the reflected light permeate through the second optical element for converging light and the half mirror to inject it into the apparatus for deflecting light; and

(d) a variable mechanism which changes a clearance along a light axile direction from the second optical element for converging light to the reflecting member.

11. A system for scanning light according to claim 4, which includes the plurality of apparatuses for deflecting light,

wherein the apparatuses for deflecting light are arranged in layers so that the parallel strips which occur in each apparatus for deflecting light will be crossed one another, and

the drive circuit applies a voltage to each of the apparatuses for deflecting light mutually.

12. A device for scanning light according to claim 4, further including;

a polarizer installed on the outgoing light side of said apparatus for deflecting light.

13. A system for scanning light according to claim 4, further including;

a polarizer which is arranged so that the polarizing direction will be almost perpendicular against the polarizing direction of the incident light of said apparatus for deflecting light, and is installed on the outgoing light side of said apparatus for deflecting light.

15. A device for reading information according to claim 14,

wherein the information medium is a bar code.

16. A device for reading information according to claim 14, further including:

shading means for cutting off a zero-dimensional diffracted light of the apparatus for deflecting light installed on the outgoing light side of said apparatus for deflecting light.

18. A device for stereoscopic display according to claim 17, further comprising:

(a) a line division unit for dividing a picture photographed by a camera into a number of visual points;

(b) a time series rearrangement unit for rearranging the two-dimensional pictures divided by said line division unit in the time series; and

(c) a two-dimensional picture display control unit for replaying and controlling the two-dimensional pictures rearranged by said time series rearrangement unit in a time series order,

wherein said beam deflection means deflects the two-dimensional pictures displayed by said two-dimensional picture display means to a virtual aperture corresponding to an camera visual point of the plural cameras.

19. A device for stereoscopic display according to claim 17,

wherein said beam deflection means deflects the pictures to the horizontal direction.

20. A device for stereoscopic display according to claim 18,

wherein said beam deflection means deflects the pictures to the vertical direction.

21. A device for stereoscopic display according to claim 17, further comprising:

first beam deflection means for deflecting the pictures to the horizontal direction; and

second beam deflection means for deflecting the pictures to the vertical direction.

22. A device for stereoscopic display according to claim 17,

wherein said two-dimensional picture display means has a picture element for displaying the pictures, and said beam deflection means is provided independently per picture element which organizes the pictures.

23. A device for stereoscopic display according to claim 17,

wherein the second two-dimensional picture display means has a picture element for displaying the pictures, and said beam deflection means is provided extending over a plurality of picture elements which organize the pictures.

24. A device for stereoscopic display according to claim 17, further including:

light diffusion means for diffusing the light to the vertical direction,

wherein said beam deflection means executes the deflection only to the horizontal direction.

25. A device for stereoscopic display according to claim 17,

wherein said beam deflection means is controlled by the deflection control unit, and the deflection control unit refers to a phase-distribution table in which a phase-distribution data are stored to determine a deflection angle of the beam deflection means.

26. A device for stereoscopic display according to claim 17, further including:

a pair of polarizing plates which are arranged before and behind said bead deflection means and whose deflecting directions are crossed in an angle of 90 degrees±

10.

27. A device for stereoscopic display according to claim 17 which provides an elimination time of the display screen in the deflection control unit which controls the beam deflection means before rewriting the screen, when the deflection is moved from one virtual aperture to the next virtual aperture by said beam deflection means, and stops the deflection during the time.

28. A device for stereoscopic display according to claim 17 which provides an elimination time of the display screen in the deflection control unit in which the beam deflection means is controlled before rewriting the screen, when the deflection is moved from one virtual aperture to the next virtual aperture by said beam deflection means, and stops the deflection during the time and darkens the intensity of the image display by the two-dimensional picture display means at the same time.

29. A device for stereoscopic display according to claim 17, further including:

a record/replay unit for recording and replaying a photographed picture.

14. A device for reading information, comprising:

(a) an apparatus for deflecting light whose liquid crystal is inserted among the transference electrodes arranged facing one another, and parallel stripes which function as a diffraction grating when the voltage is applied to the transference electrodes are produced at a pitch corresponding to the applied voltage in the liquid crystal;

(b) a drive circuit which applies a voltage whose voltage value changes temporally among the transference electrodes of said apparatus for deflecting light;

(c) a light source which beams the light which will be injected into said apparatus for deflecting light; and

(d) an apparatus for detecting light which detects a reflected light when the scanning light diffracted by said apparatus for deflecting light is reflected in a information medium.

17. A device for stereoscopic display, comprising:

(a) two-dimensional-picture-display means for displaying two-dimensional pictures which vary in visual directions;

(b) beam deflection means for deflecting a light beamed from a picture element which organizes the pictures of said picture display means,

wherein the apparatus for deflecting light whose liquid crystal is inserted among the transference electrodes, and parallel strips which function as a diffraction grating when a voltage is applied among the transference electrodes are produced at a pitch corresponding to the applied voltage in the liquid crystal is used for said beam deflection means.

30. A system for stereoscopic picture communication which comprises a transmission side that transmits a plurality of two-dimensional pictures which vary in directions and a receiving side that receives the transmitted two-dimensional pictures, and displays the two-dimensional pictures by the two-dimensional image display means and displays a stereoscopic picture in a remote location by deflecting the light beamed from the picture element which organizes the pictures of said image display means corresponding to the varied visual directions in said beam deflection means,

wherein an apparatus for deflecting light whose liquid crystal is inserted among the transference electrodes arranged facing one another, and parallel stripes which function as a diffraction grating when the voltage is applied among the transference electrodes are produced at a pitch corresponding to the applied voltage is used for said beam deflection means.