JPH11160635A - Optical element and manufacturing method thereof and device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical element little restricted in light quantity of incident light with little changes due to the elapse of time even if the structure body is exothermic with heat generated by irradiation of light. SOLUTION: Peripheral parts of predetermined effective areas of respective thin films 12 are supported on a substrate 11 via supporting parts 13 so that the effective areas of respective thin films 12 are superimposed with a space between each other. The plural thin films 12 show a predetermined optical characteristic as a whole. An electrode layer 14 is formed on the substrate 11 under the effective area of the plural thin films 12. An electrode layer 15 is formed on the uppermost thin film 12. When a voltage impressed between the electrodes 14, 15, the effective areas of respective thin films 12 are attracted to the substrate 11 by the electrostatic force generated between the electrodes 14, 15, and all the spaces between the plural thin films are substantially lost in the effective areas, and the plural thin films are changed in optical characteristic as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element for controlling optical characteristics such as light reflection and transmission characteristics, a method of manufacturing the same, and an apparatus using the optical element.

[0002]

2. Description of the Related Art In recent years, various micromachines have been actively researched and developed utilizing semiconductor manufacturing technology. The results of research have also been applied to optical elements that have microscopic mirrors integrated in a plane.

In a micro-optical element which has been reported, a large number of metal mirrors each having a size of tens of μm square are integrated on a substrate surface, and these mirrors are driven by an electrostatic force between an electrode provided on the substrate and the mirrors. A method is used in which the angle of a mirror is changed to control the angle of reflection of incident light by each mirror (for example, Larry J. Hornbeck, Technical Diegestof).
the 14th Sensor Symposium, 1996, pp297-304).

FIG. 8 is a view schematically showing a schematic sectional structure of such a conventional micro optical element. Electrode layers 2a and 2b are provided on a substrate 1, and a movable mirror portion 4 supported by a torsion hinge 3 is formed on the electrode layers 2a and 2b. The movable mirror unit 4 includes a drive electrode film 5 whose center is supported by a torsion hinge, and a reflection mirror 7 formed of a metal thin film connected to the drive electrode film 5 via a post 6 at the center. Have been. One side electrode layer 2
When a voltage is applied to a, a portion of the drive electrode film 5 on the side of the electrode layer 2a is attracted to the substrate 1 side, and a rotational force about the torsion hinge 3 is generated, and the reflection mirror section 7 is inclined. Thereby, the reflection direction of the light incident on the reflection mirror unit 7 is controlled. This optical element is used, for example, as a spatial light modulator (light valve) for a projection display device (projector) by projecting only light reflected in a specific reflection direction on a screen.

[0005]

However, in the conventional optical element as shown in FIG. 8, the reflecting mirror 7 made of a metal thin film has only a central portion supported by the post 6, so that the light irradiating light is not emitted. Deformation due to warping of the reflecting mirror 7 due to heat generated by the
The constraint on the intensity of the incident light is large. In addition, in the conventional optical element as shown in FIG. 8 described above, since the reflection mirror 7 made of a metal thin film has only a central portion supported by the post 6, even if the intensity of the incident light is not so large, As the stress due to the heat generated by the reflection mirror 7 due to light irradiation accumulates over time, deformation such as warpage of the reflection mirror 7 easily occurs, and deformation such as warpage of the reflection mirror 7 easily occurs over time.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an optical element and an optical element which are less restricted by the amount of incident light and have little change with time even when heat is generated in a structure caused by light irradiation. It is an object to provide a manufacturing method and an apparatus using the optical element.

[0007]

In order to solve the above-mentioned problems, an optical element according to a first aspect of the present invention is arranged such that a predetermined effective area and a substrate overlap with each other at an interval on the substrate. A plurality of thin films each having a peripheral portion of the effective region supported by the substrate via a supporting portion, wherein the effective regions of the plurality of thin films exhibit predetermined optical characteristics as a whole. And a plurality of electrode layers,
When an electric field is applied between at least two electrode layers of the plurality of electrode layers, the electrostatic force (attraction force or repulsion force) acting between them may be determined according to the following:
At least one of the plurality of thin films is elastically deformed so that at least one of the spaces between the plurality of thin films substantially disappears or changes, so that the effective area of the thin film is reduced. And a plurality of electrode layers displaced with respect to the substrate.

According to the first aspect, the effective regions of the plurality of thin films overlap with an interval therebetween, and therefore, as well as the known optical multilayer film, these effective regions as a whole also include the interval portion. Shows the optical characteristics of When an electric field is applied between at least two of the plurality of electrode layers, at least one of the plurality of thin films is elastically deformed in accordance with an electrostatic force acting between the two. The effective area of the thin film is displaced relative to the substrate,
At least one of the spacings between the plurality of thin films is substantially eliminated or changes. For this reason,
By applying an electric field (ie, applying a voltage or potential to the electrode layer), the optical characteristics of the plurality of thin films as a whole change depending on the magnitude.

As described above, according to the first aspect, the principle of the optical multilayer film and the displacement of the thin film due to the electrostatic force are skillfully integrated, and by controlling the application of voltage or potential to the plurality of electrode layers. The resulting optical properties can be controlled.

As the optical characteristics, as is known for optical multilayer films, various optical characteristics according to the purpose are set by appropriately determining the number, refractive index, thickness, interval, etc. of the plurality of thin films. For example, transmission characteristics (or reflection characteristics) for incident light in a predetermined wavelength region can be mentioned. Each thin film may be a single layer made of a single material, or may be made of a plurality of layers made of a plurality of materials.

Further, the control of the optical characteristics is not limited to simply switching between two states (for example, a transmission state and a reflection state), but also the number and arrangement of the plurality of electrode layers, the applied voltage or the magnitude and voltage of the applied potential. By appropriately setting the selection of the electrode layer to which is applied, control of three or more steps or continuous control (for example, stepwise control or continuous control of transmittance) is also possible.

In the first aspect, the peripheral portions of the effective regions of the plurality of thin films need only be supported by the support portion, and the entire peripheral portions of the effective regions do not necessarily need to be supported. For example, only a pair of opposing sides in the periphery of the effective area may be supported. In the first aspect, since the periphery of the effective region of the plurality of thin films is supported, even if the intensity of incident light is high and the heat generation of the thin film by the light irradiation is relatively large, the thin film warps. And the like, the deformation of the incident light is not so limited. In the first aspect,
Since the periphery of the effective area of the plurality of thin films is supported, even if stress due to heat generation of the thin film due to light irradiation accumulates over time, deformation such as warpage of the thin film hardly occurs, and even over time. Deformation such as warping of the thin film is unlikely to occur.

An optical element according to a second aspect of the present invention is the optical element according to the first aspect, wherein the interval between the plurality of thin films forms an air layer.

In the second aspect, since the air gap is formed between the thin films, the element structure is simplified and the cost is reduced. However, in the first aspect, for example, the gap between the thin films forms a vacuum layer or a liquid layer by, for example, housing the optical element in a predetermined container and disposing the optical element in a vacuum or a liquid having a predetermined refractive index. You may do so.

The optical element according to a third aspect of the present invention is the optical element according to the first or second aspect, wherein at least one of the plurality of electrode layers has the effective area of the plurality of thin films. And wherein at least one other electrode layer of the plurality of electrode layers is located on the effective region of the thin film located farthest from the substrate in the effective region of the plurality of thin films. It is formed in the area.

The third embodiment is an example of the arrangement of a plurality of electrode layers in the first and second embodiments. In the third aspect, for example, when a relatively large electric field is applied between the electrode layer formed on the substrate and the electrode layer formed on the effective region of the farthest thin film, the effective region of the farthest thin film is changed to the substrate. The effective areas of the other thin films are also attracted to the substrate, whereby the effective areas of the plurality of thin films are all substantially eliminated, and the effective areas of the plurality of thin films are optically combined into a single film as a whole. Can function as Therefore, the largest change in optical characteristics can be obtained only by disposing the two electrode layers, which is preferable.

However, in the first and second aspects,
The arrangement of the plurality of electrode layers is not limited to the example as in the third aspect. For example, the electrode layers are formed on the substrate under the effective area of the plurality of thin films and the plurality of thin films are formed. An electrode layer may be formed on an effective area of any one or more thin films (all thin films may be used) of the thin films, or an electrode layer may be formed on the substrate without forming the electrode layer. An electrode layer may be formed in an effective region of any two or more thin films (or all thin films).

When the electrode layer is formed on the substrate as in the third aspect, the thin film located closest to the substrate is formed on the electrode layer without any gap from the electrode layer. It may be formed directly.

An optical element according to a fourth aspect of the present invention is the optical element according to any one of the first to third aspects, wherein the effective regions of the plurality of thin films have a tensile stress. .

According to the fourth aspect, since the effective regions of the plurality of thin films have a tensile stress, when the effective regions of the thin film are displaced by the electrostatic force and the static force disappears, This is preferable because the effective area easily returns to the original position automatically. However, in the first to third aspects, the effective regions of the plurality of thin films do not necessarily have to have a tensile stress.

An optical element according to a fifth aspect of the present invention is the optical element according to any one of the first to fourth aspects, wherein each of the plurality of thin films is a silicon nitride film.

In the fifth aspect, examples of the plurality of thin films are given. However, in the first to fourth aspects, the material of the plurality of thin films is not limited to silicon nitride.

An optical element according to a sixth aspect of the present invention is the optical element according to any one of the first to sixth aspects, wherein the substrate has a property of transmitting predetermined light.

In the case where light transmitted through the plurality of thin films is used, for example, as in the sixth embodiment, a substrate such as glass having a light transmitting property with respect to the light may be used. . However, for example, when utilizing the light reflected by the plurality of thin films, the substrate need not have translucency.

An optical element according to a seventh aspect of the present invention is the optical element according to any one of the first to sixth aspects, wherein the effective regions of the plurality of thin films and the plurality of electrode layers are formed as one unit element. The unit elements are arranged one-dimensionally or two-dimensionally with respect to the substrate.

In the first to sixth embodiments, only one unit element may be provided. However, as in the seventh embodiment, a plurality of unit elements can be arranged one-dimensionally or two-dimensionally. For example, a one-dimensional or two-dimensional spatial light modulator can be obtained.

According to an eighth aspect of the present invention, there is provided a method of manufacturing an optical element according to any one of the first to seventh aspects, wherein the plurality of electrodes are provided on the substrate. Forming a stacked body composed of a layer, a plurality of sacrificial layers to form the gap, and the plurality of thin films, forming the support, and removing the plurality of sacrificial layers. Things.

The eighth aspect is an example of the method of manufacturing the optical element according to the first to seventh aspects. If the manufacturing method according to the eighth aspect is adopted, the optical element can be manufactured using a semiconductor manufacturing technique. Since an optical element can be manufactured and batch production is possible, a low-cost optical element can be provided.

According to a ninth aspect of the present invention, there is provided a projection display apparatus comprising at least one spatial light modulation element, and projecting light modulated by the at least one spatial light modulation element. At least one spatial light modulation element is the optical element according to the seventh aspect.

A laser printer according to a tenth aspect of the present invention irradiates a photosensitive drum with a laser beam modulated by an optical modulator, wherein the optical modulator is an optical element according to the seventh aspect. Things.

The ninth and tenth aspects show examples of the application of the optical element according to the seventh aspect, but the optical element according to the seventh aspect is used in various other apparatuses. It goes without saying that it can be done.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an optical element according to the present invention, a method for manufacturing the same, and an apparatus using the same will be described with reference to the drawings.

First, the schematic structure and principle of an optical element according to an embodiment of the present invention will be described with reference to FIG.

FIG. 1 is a schematic sectional view schematically showing the operation principle of the optical element according to the present embodiment. FIG. 1A shows a state in which the optical element is not driven, and FIG. The state is shown.

As shown in FIG. 1, the optical element according to the present embodiment includes a substrate 11 made of glass or the like, which is transparent to light to be used (light of a predetermined wavelength), and a plurality of thin films 1.
2, a support 13, and a plurality of electrode layers 14 and 15.

As shown in FIG. 1A, the periphery of the predetermined effective area of each thin film 12 is formed on the substrate 11 so that the effective area of each thin film 12 overlaps the substrate 11 at intervals. Is supported via the support portion 13. In the present embodiment, the effective area is a rectangular area, and the entire periphery thereof is supported by the support 13. However, the shape of the effective area is not limited to a rectangle, and without supporting the entire periphery of the effective area,
For example, only a pair of opposing sides in the periphery of the effective area may be supported. Further, in the present embodiment, the space between the thin films 12 forms an air layer. However, the optical element is housed in a predetermined container and placed in a vacuum or a liquid having a predetermined refractive index. The interval between the 12 may form a vacuum layer or a liquid layer. Further, in the present embodiment, the effective area of each thin film 12 is supported by the support 13 so as to have a tensile stress.
However, in the present invention, the effective area of each thin film 12 does not necessarily have to have a tensile stress.

The plurality of thin films 12, as known in an optical multilayer film, exhibit predetermined optical characteristics as a whole including the air layer, depending on the wavelength of light used and the incident angle thereof. The material, thickness, number, interval, period, etc. are determined. In the present embodiment, the plurality of thin films 12 are set so as to exhibit characteristics of reflecting light incident from the back surface of the substrate 11 as a whole.

The plurality of electrode layers 14 and 15 are formed according to an electrostatic force acting between at least two of the plurality of electrode layers 14 and 15 when an electric field is applied between them. At least one of the plurality of thin films 12 is elastically deformed so that at least one of the spaces between the plurality of thin films 12 substantially disappears or changes. The region is arranged so as to be displaced with respect to the substrate 11. Specifically, in the present embodiment, only two electrode layers 14 and 15 are provided as the plurality of electrode layers, and
4 is formed on the substrate 11 below the effective area of the plurality of thin films 12, and the electrode layer 15 is formed on the uppermost thin film 12 (substrate 11).
Is formed on the thin film 12) located farthest from the thin film. However, in the present invention, the number and arrangement of the plurality of electrode layers are not limited to the example as in the present embodiment. For example, while the electrode layer 14 formed on the substrate 11 is An electrode layer may be formed on an effective area of any one or more of the thin films 12 (or all the thin films 12), or a plurality of thin films may be formed on the substrate 11 without forming the electrode layer. An electrode layer may be formed in an effective region of any two or more of the thin films 12 (or all the thin films 12).

The electrode layers 14 and 15 may be appropriately divided into a plurality of layers. Further, in the present embodiment, a space is provided between the lowermost thin film 12 (the thin film 12 located closest to the substrate 11) and the electrode layer 14, but the lowermost thin film 12 is 14 may be formed directly.

In the present embodiment, the electrode layers 14 and 1
As 5, a light-transmitting material for the light to be used is used. Specifically, for example, I
A TO film may be used, and a metal film having a sufficiently small thickness (for example, a metal film having a light-transmitting property with respect to visible light as long as the thickness is sufficiently small) can be used as the electrode layer 15. .
However, in the present invention, any one of the electrode layers 14 and 15 may have a property of transmitting light to be used. For example, only the electrode layer 15 has translucency and the electrode layer 14
1 does not have a light-transmitting property, incident light is made incident from above the substrate 11 and light transmitted through the plurality of thin films 12 is absorbed on the electrode layer 15 so as to be absorbed, contrary to the case shown in FIG. A film may be formed, and light reflected by the plurality of thin films 12 may be used. In such a case, it is needless to say that the substrate 11 does not need to have a light-transmitting property with respect to the light used.

According to the present embodiment, when a voltage is applied between the electrodes 14 and 15 or when a predetermined potential is not applied to the electrodes 14 and 15 (that is, when the electrodes 14 and 15 are not driven), as described above, The thin films 12 are spaced apart from each other, and light incident from the back surface of the substrate 11 is reflected by the plurality of thin films 12, and the plurality of thin films 12 include the air layer therebetween. The whole functions as a reflection film.

On the other hand, when a relatively high voltage is applied between the electrodes 14 and 15 so as to generate an electric field in which an attractive electrostatic force is generated between the electrodes 14 and 15, as shown in FIG. The force pulls the effective area of the uppermost thin film 12 to the substrate 11, whereby the other thin films 12 are also attracted to the substrate 11, and the gaps between the effective areas of the plurality of thin films 12 are substantially eliminated. The 12 effective areas function as a single optical film as a whole, and most of the incident light passes through the plurality of thin films 12. On this occasion,
As shown in FIG. 1B, a peripheral portion of the effective area is elastically deformed, and an inner portion thereof is displaced substantially in parallel.

When the voltage between the electrodes 14 and 15 is turned off, the electrostatic force disappears, and each thin film 12 returns to the state shown in FIG. 1A due to its own elasticity. In this process, the same potential may be applied to each of the electrodes 14 and 15 to generate a repulsive electrostatic force between the electrodes 14 and 15 to promote the return to the state shown in FIG.

With the above operation, the optical element according to the present embodiment can control the transmission and reflection of incident light by turning on and off the voltage between the electrodes 14 and 15.

In the operation example described above, transmission and reflection are two.
Although the three states are switched, the transmittance (or reflectance) can be controlled in three or more steps or continuously controlled by appropriately setting the magnitude of the voltage between the electrode layers 14 and 15. it can.

In the operation example described above, the electrodes 14, 1
Although an example was described in which a voltage was applied between the electrodes 5 and an electrostatic force of a suction force was applied between them to change the optical characteristics, in the present embodiment, the same potential is applied to each of the plurality of electrodes, and It goes without saying that optical characteristics may be changed by applying a repulsive electrostatic force.

In this embodiment, a plurality of thin films 1
Since the periphery of the effective area 2 is supported, even if the intensity of the incident light is high and the heat generation of the thin film 12 by the light irradiation is relatively large, deformation such as warping of the thin film 12 hardly occurs. However, the intensity of the incident light is not so limited. Also,
In the present embodiment, since the periphery of the effective area of the plurality of thin films 12 is supported, even if stress (generally, tensile stress) due to heat generation of the thin film 12 due to light irradiation accumulates over time, the thin film 12 is not affected by the heat. Deformation such as warpage of the thin film 12 hardly occurs, and deformation such as warpage of the thin film 12 hardly occurs over time.

Here, in the present embodiment, the substrate 11
A plurality of thin films 12 on the substrate 11 with a thickness of 100 nm and a pitch of 200 nm.
FIG. 2 shows optical characteristics of the optical element obtained when a silicon nitride thin film having a layer formed is used. FIG. 2 shows the electrodes 14,
The wavelength of the incident light is 612 nm and is parallel to the substrate 11 (the incident angle is 90 degrees) between the case where no voltage is applied between 15 (when not driving) and the case where a voltage of 5 V is applied (when driving).
3 shows the transmittance of the optical element at an angle from to an angle of normal incidence (incident angle of 0 degree). As is apparent from FIG. 2, at an incident angle of about 50 degrees, the transmittance is almost 0% when not driven, the transmittance is about 80% when driven, and switching between reflection and transmission is performed. It can be seen that the operation is performed.

By the way, only one unit element may be arranged on the substrate 11 by using the effective areas of the thin films 12 and the electrode layers 14 and 15 as one unit element, although not shown in FIG. Alternatively, a plurality of unit elements may be arranged on the substrate 11. When a plurality of unit elements are arranged, they may be arranged only one-dimensionally or two-dimensionally.

Next, an example of a method of manufacturing the optical element according to the present embodiment will be described with reference to FIGS.

FIG. 3 is a schematic diagram showing a manufacturing process of the optical element according to the present embodiment, FIG. 4 is a schematic diagram showing a process subsequent to the process shown in FIG. 3, and FIG. 5 is an embodiment obtained by this manufacturing method. 1 is a schematic diagram showing a specific structure of an optical element according to the present invention. FIGS. 3A to 3B, 4A to 4C, and 5B and 5C are schematic cross-sectional views. FIG. 3D and FIG. 5A are plan views. FIG. 3 (c) and FIG. 3 (d)
Indicates the same step. FIG. 5B shows a cross section taken along line X1-X1 in FIG. 5A, and FIG.
3A shows a cross section along the line X2-X2 in FIG. 3 (a) to 3 (c) and FIGS. 4 (a) to 4 (c) show FIG.
2 shows a cross section corresponding to the cross section shown in FIG. In addition,
FIG. 1 is a conceptual diagram and does not necessarily correspond to FIG. 5 in the drawing.

The manufacturing method according to the present embodiment is an example of a method for manufacturing an optical element in which a plurality of unit elements are arranged two-dimensionally.
It goes without saying that an optical element having only a single unit element or an optical element in which a plurality of unit elements are arranged one-dimensionally can be manufactured by the same method.

First, on a glass substrate 21 (corresponding to the substrate 11 in FIG. 1) having a diameter of 3 inches, a plurality of transparent electrode layers 24 (corresponding to the electrode layer 14 in FIG. 1) according to the arrangement of the unit elements. Is patterned (FIG. 3A).

Next, on the substrate in the state shown in FIG.
After forming a 200 nm thick silicon oxide film 23 as a sacrificial layer, a 100 nm thick silicon nitride film 22 (corresponding to the thin film 12 in FIG. 1) having a tensile stress is further formed by a sputtering method. By appropriately setting the temperature conditions and the like during this film formation, a tensile stress can be applied to the silicon nitride film 22. Then, this silicon oxide film 23
And a silicon nitride film 24 as one pair, a stacked body of 20 pairs of multilayer films is formed (FIG. 3B). However, the thickness of the uppermost silicon nitride film 24 is the same as the thickness of the silicon nitride film 25 described later.
And 200 nm in total.

Thereafter, a lattice-like groove 26 is formed in the multilayer body of the multilayer film according to the arrangement of the unit elements by dry etching, and the multilayer body is divided into a plurality of 20 μm square laminates (FIG. 3 (c) (d)).

Next, a silicon nitride film 25 is again formed on the substrate in the state shown in FIGS. 3C and 3D by the sputtering method (FIG. 4B). As is clear from FIG. 4B, the portion of the silicon nitride film 25 formed in the trench 26 is
It corresponds to the support 13 in the middle. Also, the portion of the silicon nitride film 25 formed on the uppermost silicon nitride film 22 and the uppermost silicon nitride film 22 together with the uppermost thin film 12 in FIG.
Is equivalent to

Next, a 5 nm-thick metal film 27 of gold or the like (corresponding to the electrode layer 15 in FIG. 1) is formed on the substrate in the state shown in FIG. 4A (FIG. 4B). .

Thereafter, with respect to the substrate in the state shown in FIG. 4 (b), a diameter of 1 μm for eluting the silicon oxide film 23 as a sacrificial layer at an arbitrary position in the plane of the multilayer body of the individual multilayer films.
Holes 28 are formed by a dry etching method (FIG. 4).
(C)).

Finally, the substrate in the state shown in FIG. 4C is immersed in an aqueous solution of hydrofluoric acid to elute and remove the silicon oxide film 23 as a sacrificial layer. As a result, FIGS.
The optical element shown in (c), that is, the optical element according to the above-described embodiment is completed. In FIGS. 4B and 4C, the portion 29 (excluding the lowermost portion) where the silicon oxide film 23 was present corresponds to the interval between the thin films 12 in FIG.

The manufacturing method described above utilizes a semiconductor manufacturing technology, and can be batch-produced, so that an inexpensive optical element can be provided.

Next, a projection type display device according to an embodiment of the present invention will be described with reference to FIG. FIG.
1 is a schematic configuration diagram illustrating a projection display device according to the present embodiment.

The projection type display device according to the present embodiment has a spatial light modulator, and projects the light modulated by the spatial light modulator onto the screen 36. The optical element shown in FIGS. 1 and 5 (in FIG. 6, denoted by reference numeral 34) is used.

In this projection type display device, the divergent light emitted from the white light source 31 is collimated by the collimator lens 32. This parallel light passes through the red filter 33 and becomes monochromatic parallel light. This light is incident on an optical element 34 shown in FIGS. 1 and 5 as a spatial light modulation element and is modulated. In the present embodiment, for example, an optical element 34 having 256 × 256 unit elements is used. As the optical characteristics of each unit element, those having the characteristics shown in FIG. 2 can be used.
Numeral 4 is arranged obliquely with respect to the optical axis so that the incident angle becomes about 50 degrees (for convenience, it is shown in FIG. 6 as being arranged perpendicular to the optical axis). The drive / non-drive of each unit element of the optical element 34 as a spatial light modulation element (that is, on / off of transmitted light of incident light) is controlled by a control signal given from the drive control unit 37 in response to a video signal.
Each is controlled independently. Thereby, the optical element 3
The monochromatic parallel light incident on 4 is modulated. The modulated light transmitted through the optical element 34 is enlarged by a projection lens 35 and projected on a screen 36, and an image corresponding to a video signal is projected on the screen 36.

In this embodiment, the light transmitted through the optical element 34 is used as modulated light.
Conversely, the reflected light may be used as the modulated light. Further, for example, it is also possible to prepare an optical system for blue and green, and combine the images of the respective colors in advance or separately project them on the same screen to project a color image on the screen. .

Next, a laser printer according to an embodiment of the present invention will be described with reference to FIG. FIG.
1 is a schematic configuration diagram showing a laser printer device according to the present embodiment.

The laser printer according to the present embodiment is a laser printer which irradiates a photosensitive drum 45 with a laser beam modulated by an optical modulator as shown in FIGS. 1 and 5 described above as the optical modulator. An optical element (in FIG. 7, denoted by reference numeral 44) is used.

This laser printer device has a laser light source 4
The laser light which is the divergent light emitted from 1 is collimated lens 4
The light is converted into a band-shaped parallel light (parallel light having a cross-sectional shape) by 2 and is incident on the optical element 44 via the reflection mirror 43. In this embodiment, for example, an optical element 44 in which 10,000 unit elements are arranged one-dimensionally is used. As the optical characteristics of each unit element, those having the characteristics shown in FIG. 2 can be used.
4 is arranged obliquely with respect to the optical axis so that the incident angle becomes about 50 degrees (in FIG. 7, it is shown as being arranged perpendicularly to the optical axis for convenience). The drive / non-drive of each unit element of the optical element 44 as the light modulation element (that is, ON / OFF of transmitted light of incident light) is controlled by a control signal given from the drive control unit 46 in response to a print image signal.
Each is controlled independently. Thereby, the optical element 4
4 is modulated. Optical element 44
The modulated light transmitted through is irradiated on the photosensitive drum 45. Thereafter, although not shown in the drawing, toner corresponding to the potential image formed on the photosensitive drum 45 is transferred to the paper and fixed.

Although the present embodiment is also configured to use the transmitted light of the optical element 44 as modulated light, it may be configured to use reflected light as modulated light.

While the embodiments of the present invention have been described above, the present invention is not limited to these embodiments.

For example, the optical element according to the present invention can be used not only in a projection display device and a laser printer device but also in various other devices.

[0071]

As described above, according to the present invention,
It is possible to provide an optical element which is less restricted by the amount of incident light and has little change with time even when heat is generated in a structure caused by light irradiation, a method for manufacturing the same, and an apparatus using the optical element.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view schematically showing an operation principle of an optical element according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of optical characteristics of the optical element shown in FIG.

FIG. 3 is a schematic view showing a manufacturing process of the optical element shown in FIG.

FIG. 4 is a schematic view showing a step that follows the step of FIG.

FIG. 5 is a schematic diagram showing an example of a specific structure of the optical element shown in FIG. 1 obtained by the manufacturing method shown in FIGS. 3 and 4;

FIG. 6 is a schematic configuration diagram illustrating a projection display device according to an embodiment of the present invention.

FIG. 7 is a schematic configuration diagram showing a laser printer device according to an embodiment of the present invention.

FIG. 8 is a diagram schematically showing a schematic cross-sectional structure of a conventional optical element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Substrate 12 Thin film 13 Support part 14, 15 Electrode layer 34, 44 Optical element 45 Photosensitive drum

Claims (10)

[Claims] A peripheral portion of each of the effective regions is supported on the substrate via a support portion such that the substrate and each predetermined effective region overlap with each other at an interval on the substrate. A plurality of thin films, wherein the effective area of the plurality of thin films exhibits predetermined optical characteristics as a whole; a plurality of electrode layers; and at least two electrode layers of the plurality of electrode layers The distance between the plurality of thin films is substantially eliminated or changed according to an electrostatic force acting between the thin films when an electric field is applied between the plurality of thin films. And a plurality of electrode layers that elastically deform at least one of the thin films to displace the effective region of the thin film with respect to the substrate. 2. The optical element according to claim 1, wherein an interval between the plurality of thin films forms an air layer. 3. At least one of the plurality of electrode layers.
One electrode layer is formed on the substrate below the effective area of the plurality of thin films, and at least one other electrode layer of the plurality of electrode layers is formed on the substrate of the effective area of the plurality of thin films. 2. The thin film located farthest from a substrate is formed in the effective area of the thin film.
Or the optical element of 2. 4. The optical element according to claim 1, wherein the effective area of the plurality of thin films has a tensile stress. 5. The optical element according to claim 1, wherein each of the plurality of thin films is a silicon nitride film. 6. The optical element according to claim 1, wherein the substrate has a property of transmitting predetermined light. 7. The method according to claim 1, wherein the effective areas of the plurality of thin films and the plurality of electrode layers constitute one unit element, and the unit elements are arranged one-dimensionally or two-dimensionally with respect to the substrate. The optical element according to claim 1. 8. The method for manufacturing an optical element according to claim 1, wherein the plurality of electrode layers, the plurality of sacrificial layers for forming the intervals, and the plurality of sacrificial layers are formed on the substrate. A method of manufacturing an optical element, comprising: forming a stacked body including a plurality of thin films; forming the support portion; and removing the plurality of sacrificial layers. 9. A projection display device comprising at least one spatial light modulation element and projecting light modulated by the at least one spatial light modulation element, wherein the at least one spatial light modulation element is provided. Projection type display device characterized by the above-mentioned optical element. 10. A laser printer for irradiating a photosensitive drum with laser light modulated by an optical modulator, wherein the optical modulator is the optical element according to claim 7.