JP3092989B2 - Light modulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical modulation device,
More specifically, the present invention relates to an apparatus for modulating light using total reflection of a prism.

[0002]

2. Description of the Related Art FIG. 9 is a perspective view showing a corner cube as an example of a prism of interest to the present invention. In the figure, a corner cube 1 has three total reflection surfaces 1a to 1c orthogonal to each other. Preferably, the corner cube 1 is made of a cylindrical resin or glass having one end side surface of 3 mm.
It is formed by cutting diagonally from one side.

[0003] A corner cube 1 as shown in FIG.
After being reflected by .about.1c, the light exits from the incident surface 1d again. At this time, the output light of the corner cube 1 follows a path parallel to and opposite to the incident light regardless of the incident angle of the incident light. Therefore, when light is applied to the corner cube 1 from a certain light source, the reflected light returns to the original position, that is, the light source. Since the corner cube 1 has such special optical properties, it is used in fields such as measurement and movement control of a moving body.

When some kind of light measurement or light control is performed using the above-mentioned corner cube,
There are times when it is desired to modulate the reflected light. FIG. 10 is a schematic block diagram showing a configuration of a conventional modulation device for modulating reflected light of a corner cube. In the figure, a liquid crystal shutter 2 is arranged in front of an incident surface 1d of a corner cube 1. The liquid crystal shutter 2 switches light incident on the corner cube 1 by being turned on and off by a liquid crystal driver 3. As a result, the reflected light from the corner cube 1 is switched and modulated in response to the opening and closing of the liquid crystal shutter 2.

[0005]

As described above, the conventional light modulator modulates light using a liquid crystal shutter. However, the liquid crystal shutter has a problem that the response speed of opening and closing is slow and is not suitable for high-frequency light transmission. Further, if the liquid crystal shutter is frequently opened and closed, the liquid crystal deteriorates quickly and there is a problem in durability. further,
The conventional light modulator simply switches the reflected light of the prism, and cannot carry pattern information on the reflected light.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an optical modulator which can operate at high speed and has excellent durability.

Another object of the present invention is to provide a light modulation device which can modulate light by carrying pattern information.

[0008]

According to a first aspect of the present invention, there is provided an optical modulator for modulating light using total reflection of a prism, wherein the optical modulator is formed in a matrix on a common transparent substrate.
Formed, each having at least one total reflection surface
Number of prisms and each prism's total reflection surface
It is arranged and its shape changes according to the applied electric field
A plurality of electrostrictive elements, and a voltage applied to each of the plurality of electrostrictive elements.
By controlling the field, the total reflection surface of multiple prisms and
Electrostrictive element driving means for changing a distance between each of the plurality of electrostrictive elements .

[0009]

[0010]

[Action] In the optical modulator according to claim 1, by the distance between the total reflection surface and the electrostrictive element <br/> prisms arranged in a matrix by electrostriction element drive means are controlled , light reflected by the total reflection surfaces of a plurality of prisms are modulated are switched respectively.

[0011]

[0012]

FIG. 1 is a diagram showing a schematic configuration of an optical modulator according to an embodiment of the present invention. In the figure, an optical modulator 4 is attached to one of the three total reflection surfaces of the corner cube 1 (total reflection surface 1b in FIG. 1). This optical modulator 4 is driven by an electrostrictive element driver 5.

FIGS. 2 and 3 are enlarged views of a portion indicated by a dotted line A in FIG. For example, as shown in FIG. 2, the optical modulator 4 includes a plurality of electrostrictive elements 41 arranged in a matrix on a common substrate 40.
An insulating spacer 42 is provided in a gap between the respective electrostrictive elements 41. Each insulating spacer 42 is made of a flexible material such as a resin. By these insulating spacers 42,
Each electrostrictive element 41 is mutually insulated, and each electrostrictive element is individually displaceably connected.

Each of the electrostrictive elements 41 is an element whose shape changes according to an applied electric field, such as tourmaline, quartz, Rochelle salt, barium titanate, potassium phosphate, and the like.
It is made of a piezoelectric material such as lead zirconate and lead titanate.

Although not shown, wiring is individually provided on the substrate 40 for each electrostrictive element 41. The electrostrictive element driver 5 individually drives each electrostrictive element 41 through these wirings.

Next, the operation of the embodiment shown in FIGS. 1 to 3 will be described. As shown in FIG. 2, each electrostrictive element 41 is arranged at a predetermined distance from the total reflection surface 1 b of the corner cube 1. Therefore, in this state, all the light that has entered the total reflection surface 1b is reflected as indicated by a dashed line and exits again from the incidence surface 1d of the corner cube 1.

On the other hand, when an electric field is applied to any one of the electrostrictive elements 41 by the electrostrictive element driver 5, the shape of the electrostrictive element 41 changes and the total reflection surface 1 of the corner cube 1 is changed.
b. As a result, on the total reflection surface of the portion where the electrostrictive element 41 is in close contact, the condition of total reflection is broken, and light is not reflected. For example, in FIG. 3, the second electrostrictive element 41 from the left and the third electrostrictive element 41 from the right are in close contact with the total reflection surface 1b, and reflection at this portion is prevented. Therefore, if the change in the shape of each electrostrictive element 41 is individually controlled by the electrostrictive element driver 5, the reflected light can be modulated so as to include arbitrary pattern information. Of course, if the shapes of all the electrostrictive elements 41 are changed collectively, the reflected light can be switched and modulated as in the conventional optical modulator.

In the embodiment shown in FIG. 1, the light modulator 4 is provided only on one of the three total reflection surfaces 1a to 1c of the corner cube 1. This is because the light incident on the corner cube 1 is always reflected by three total reflection surfaces and then emitted to the outside from the incident surface 1d. Therefore, the optical modulator 4 is provided only on one total reflection surface. This is because the reflected light can be modulated.

FIG. 4 is a block diagram showing a schematic configuration of an optical modulator according to another embodiment of the present invention. In the figure, a plurality of corner cubes 61 are integrally formed on one surface of a transparent substrate 6. Each corner cube 61
Has three total reflection surfaces orthogonal to each other, similarly to the corner cube 1 shown in FIG. One of the three total reflection surfaces of each corner cube 61 has an optical modulator 8
Is provided. Each optical modulator 8 is individually controlled by an electrostrictive element driver 9.

FIGS. 5 and 6 are enlarged views of a portion indicated by a dotted line B in FIG. As shown in FIG. 5, an electrostrictive element 81 is arranged at a predetermined interval on any one of the total reflection surfaces of the corner cube 61. The electrostrictive element 81 is
The corner cube 61 is held by fixing members 82 arranged at both ends of the total reflection surface.

Next, the operation of the embodiment shown in FIGS. 4 to 6 will be described. Usually, the electrostrictive element 81 is arranged at a predetermined distance from the total reflection surface of the corner cube 61 (see FIG. 5). In this state, the reflection of light on the total reflection surface is not hindered. On the other hand, the electrostrictive element driver 9
When an electric field is applied, the shape of the electrostrictive element 81 changes, and the electrostrictive element 81 adheres to the total reflection surface of the corner cube 61 as shown in FIG. Thereby, reflection of light on the total reflection surface of the corner cube 61 is hindered. Therefore, if the electrostrictive element 81 is intermittently changed by the electrostrictive element driver 9, the reflected light can be modulated.

The embodiment shown in FIGS. 4 to 6 corresponds to FIGS.
As in the embodiment shown in FIG. 3, by individually controlling each light modulator 8, the reflected light can be modulated so as to include arbitrary pattern information. Further, each electrostrictive element 81
, The reflected light can be switched and modulated.

FIG. 7 is a block diagram showing a schematic configuration of an optical modulator according to still another embodiment of the present invention. In the figure, a plurality of prisms 101 are integrally formed on one surface of a transparent substrate 10. Each prism 101
Are arranged, for example, in a matrix and each have at least one total reflection surface. Each prism 101 in FIG. 7 may have a configuration capable of totally reflecting light incident on the transparent substrate 10 on each of the total reflection surfaces, and does not need to be a corner cube. Of course, each prism 101
May be configured as a corner cube 61 as shown in FIG. A transparent object 12 such as resin or glass is arranged so as to face the total reflection surface of each prism 101. Each transparent object 12 is placed on a common transparent substrate 11,
It is fixedly held by the electrostrictive element 13. Although not shown, wiring is provided for each of the electrostrictive elements 13 on the transparent substrate 11, and an electrostrictive element driver 14 is provided.
Controls each of the electrostrictive elements 13 individually through these wirings.

FIG. 8 is a view showing a state in which each transparent object 12 is brought into close contact with the prism 101 in the embodiment shown in FIG. The operation of these embodiments will be described below with reference to FIGS.

First, as shown in FIG.
Are arranged at a distance from the total reflection surface of each prism 101, all light incident on the transparent substrate 10 is reflected by the total reflection surface of the prism 101. On the other hand, when an electric field is applied to each electrostrictive element 13 by the electrostrictive driver 14 and the shape of each electrostrictive element 13 changes, each transparent object 1
2 is in close contact with the total reflection surface of each prism 101. In this state, reflection on the total reflection surface of each prism 101 is hindered. Therefore, all the incident light passes through the transparent object 12. As a result, transmitted light is obtained from the other surface of the transparent substrate 11. Therefore, if the change in the shape of each electrostrictive element 13 is controlled by the electrostrictive element driver 14, the transmitted light can be modulated.

If the distance between the total reflection surface of each prism 101 and each transparent object 12 is made very short, only light having a wavelength shorter than the distance can be transmitted.
Therefore, if the distance between the total reflection surface of each prism 101 and each transparent object 12 can be controlled, FIG.
Also, the embodiment shown in FIG. 8 can be used as a color filter.

[0027]

As described above, according to the present invention, since the light is modulated according to a completely different principle from the conventional optical modulator, an optical modulator having excellent responsiveness and durability can be obtained. be able to.

The prisms are arranged in a matrix.
By placing an electrostrictive element on each total reflection surface,
Thus, the reflection of light can be individually controlled, and the light can be modulated to include pattern information.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an optical modulation device according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of the light modulation device shown in FIG.

FIG. 3 is a diagram showing a state where the shape of any one of the electrostrictive elements is controlled to change in the optical modulator shown in FIG. 2;

FIG. 4 is a diagram showing a schematic configuration of an optical modulation device according to another embodiment of the present invention.

5 is a partially enlarged view of the light modulation device shown in FIG.

FIG. 6 is a diagram showing a state where the shape of an electrostrictive element is controlled to change in the optical modulator shown in FIG. 5;

FIG. 7 is a diagram showing a configuration of an optical modulation device according to still another embodiment of the present invention.

8 is a diagram showing a state where the shape of each electrostrictive element is controlled to change in the embodiment shown in FIG. 7;

FIG. 9 is a perspective view showing a corner cube as an example of a prism of interest to the present invention.

FIG. 10 is a diagram illustrating a configuration of a conventional light modulation device.

[Description of Signs] 1,61: Corner cube 4,8: Optical modulator 5,9,14: Electrostrictive element driver 41,81,13: Electrostrictive element 101: Prism

────────────────────────────────────────────────── ─── Continuation of the front page (72) Nobuo Komatsu Inventor Park Heights 102, 22-22-13 Minami Yada, Higashi Sumiyoshi-ku, Osaka (56) References JP-A-2-254405 (JP, A) JP-A Sho53 -115247 (JP, A) JP-A-54-38146 (JP, A) JP-A-60-117210 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 26/00- 26/08

Claims (1)

(57) [Claims] An apparatus for modulating light using total reflection of a prism, wherein the apparatus is formed in a matrix on a common transparent substrate.
A plurality of prism <br/> beam each having at least one total reflection surface, the arranged plurality of the total reflection surface of the prism, a plurality of the shape changes in accordance with a given field electrostrictive element, and by controlling the electric field that gives each of the plurality of electrostrictive elements comprises electrostrictive element drive means for changing each distance between the total reflection surface and the plurality of electrostrictive elements of the plurality of prisms, the plurality thereby reflection of light by the total reflection surface of the pre-<br/> prism of the reflected light is switched is modulated respectively, the optical modulation device.