JP2002277762A - Light modulator and its driving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a light modulator which is suitable for usage as an optical writer in an electronic photographing process. SOLUTION: An EL element 304 is formed on a package upper lid 302 so as to face multiple beams 101 which constitute multiple optical switches. A projected shape part 303 for collecting lights from the EL element to the beams 101 is formed on the package upper lid 302. When the respective beams 101 are driven, the lights reflected against a light reflection surface 106 are outputted from a window 313 of a shield film 306 to the outer part of the package.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light modulation device for switching light by deforming a beam, and more particularly to a light modulation device suitable for use as an optical writing device in an electrophotographic process in a digital copying machine or a printer. Related to the device.

[0002]

2. Description of the Related Art Due to the spread of personal computers and the like, inexpensive printers having image quality comparable to laser printers have become popular. As such a printer, there is a printer that directly writes on a photoconductor using a light emitting diode array. For example, an optical printer head using an electroluminescence (EL) element array is disclosed in Japanese Patent Laid-Open No. 8-48052. Such an optical printer head is advantageous for reducing the size of an electrophotographic printer, and is attracting attention for application to a color printer.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel light modulation device suitable as an optical writing device for an electrophotographic process.

[0004]

According to a first aspect of the present invention, there is provided an optical modulator comprising: a fixed electrode; a beam having a light reflecting surface facing the fixed electrode via a gap; Are formed in the same package, and the beam is deformably held toward the fixed electrode by electrostatic force during driving, and light generated by the light emitting element during driving and non-driving of the beam emits the beam. The light is reflected in different directions by the upper reflecting surface, and the light reflected by the reflecting surface is output to the outside of the package during driving or non-driving.

Another feature of the light modulator of the present invention is that
According to another aspect of the present invention, the beam is a fixed beam at both ends. Another feature is that the light emitting device is an electroluminescent device. Another feature is that, as in claim 4, the fixed electrode and the beam are formed on the same substrate, and the light emitting element is formed on a package upper lid joined to the substrate, facing the beam. That is. Another feature is
According to a fifth aspect of the present invention, a convex portion for condensing the light generated by the light emitting element on the beam is formed on the package upper lid. Another feature is that, as described in claim 6, the fixed electrode, the beam and the light emitting element are formed on the same substrate, and the light generated by the light emitting element is applied to a package top lid bonded to the substrate. That is, a concave mirror for focusing light on the beam is formed. Another feature is that, as described in claim 7, the fixed electrode, the beam and the light emitting element are formed on the same substrate, and guide light generated by the light emitting element to the gap in the substrate. That is, a waveguide is formed. Another feature is claim 8
As described above, a light-shielding film is formed on the package upper lid, and light reflected on the light reflecting surface on the beam is output to the outside of the package through a window provided in the light-shielding film.

Another feature of the present invention is that, in driving the light modulation device, the light emitting element does not emit light during the beam displacement process.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. << Embodiment 1 >> FIGS. 1A and 1B are schematic cross-sectional views for explaining the configuration of an embodiment of the light modulation device of the present invention. FIG. 1A shows a non-driving state, and FIG. . In FIG. 1, reference numeral 102 denotes a substrate, which has a shape elongated in a direction perpendicular to the plane of the drawing. A long groove is formed in the substrate 102 in the longitudinal direction, and a fixed electrode 103 is formed in the groove. An electrode pad for the fixed electrode 103 is provided, but is not shown. On the upper surface of the substrate 102, a beam 101 facing the fixed electrode 103 via a gap 105 is formed. The beam 101 is a fixed beam at both ends in this embodiment, but may be a fixed beam at one end. Beam 101
Are formed side by side in the longitudinal direction of the substrate 102.
A metal film 106 is formed on each beam 101. The metal film 106 serves as a light reflecting surface and also functions as an electrode. The metal film 106 is formed on the electrode pad 10 at the end of the substrate 102.
7 have been drawn.

A spacer 301 long in the longitudinal direction of the substrate is bonded on the substrate 102, and a package upper lid 302 made of a transparent material long in the longitudinal direction of the substrate is bonded on the spacer 301. A light emitting element 304 having a light emitting surface long in the longitudinal direction of the substrate is formed on the package upper lid 302. In this embodiment, the light emitting element 304 is an organic or inorganic electroluminescent (EL) element. In order to condense the light emitted from the light emitting element 304 toward the metal film 106 on the beam 101, a convex part 303 is formed on the package upper lid 302, and the light emitting element 304 is formed on that part. In the present embodiment, the protruding portion 303 has a convex shape that is long in the longitudinal direction of the substrate. However, the shape is not limited to this. For example, a spherical shape corresponding to each beam 101 can be used. An electrode pad 305 supplies power to the light emitting element 304. Reference numeral 307 denotes a protective film for the light emitting element 304. On the lower surface of the package upper lid 302, for example, a Cr thin film is formed as a light shielding film 306. This light shielding film 306
A window 314 for allowing light from the light emitting element 304 to enter the beam 101 and a window 313 for passing reflected light from the beam 101 are formed in one-to-one correspondence with the beam 101. .

Next, the operation of the light modulation device will be described.
When no drive voltage is applied between the electrode pad 107 corresponding to any of the beams 101 and the electrode pad (not shown) of the fixed electrode 103 serving as a common electrode, all the beams 101
Is flat as shown in FIG. Therefore, the light L incident from the light emitting element 304 is applied to the window 313 on the metal film 106 (light reflecting surface) on each beam 101 as shown in FIG.
The light is reflected in a direction deviated from the light-shielding film 30.
6 and do not go outside.

An electrode pad 1 corresponding to the selected beam 101
07 when the drive voltage is applied, the selected beam 1
01 is attracted to the fixed electrode 103 by electrostatic attraction,
It is deformed as shown in FIG. As a result, the incident light is transmitted through the window 3 by the metal film 106 on the selected beam 101.
The light is reflected in the direction of 13 and output to the outside.

When the application of the driving voltage to the electrode pad 107 of the selected beam 101 is stopped, the beam 101 returns to a flat state as shown in FIG. Will not go outside.

Since the beam 101 is a fixed beam at both ends, extra vibration during restoration is less likely to occur as compared with the case of a beam fixed at one end, and high-speed driving is possible.

In the process of displacing the beam 101, the light emitting element 30
By stopping the light emission of 4, it is possible to prevent extra light output during the displacement of the beam 101. This is the same in each of the embodiments described later. Also, the beam 101 and the light emitting element 304
By changing the positional relationship, it is possible to emit reflected light to the outside when the beam 101 is not driven, and to prevent reflected light from being emitted to the outside when the beam 101 is driven. The same applies to the case.

As described above, this light modulator (and the light modulator of each embodiment described later) includes a plurality of optical switches each including the beam 101 and the light emitting element 304 serving as a common light source. Are provided in the same package, and can be used, for example, as an optical writing device in an electrophotographic process. Unlike the case where the light source and the optical switch are separated from each other, there is no need to position the light source and the optical switch, and there is no need to interpose a special optical system between the light source and the optical switch. Can be omitted.

With the recent improvement in image quality of digital copiers and printers, the number of pixels of the optical writing device has increased, and it has become difficult to correct the amount of light for each pixel. In the light modulation device of the present invention, since a common light source is used for a plurality of optical switches, the spatial distribution of the light amount for each optical switch (each pixel) is gentle, and the correction of the light amount for each pixel is easy.

Next, an example of a method for manufacturing the light modulation device will be described with reference to FIGS. 2 to 6 are process explanatory diagrams, and FIG. 7 is a detailed diagram of the light emitting element 304.

First, the manufacturing process on the substrate side will be described.

<< FIG. 2 (a) >> A groove serving as a void is patterned on the Si substrate 102 with an organic photoresist. For example, a groove is formed by dry etching using RIE (reactive ion etching) of SF6 gas. When forming an inclination in the groove, a gradation is provided on the photomask, and the inclination is formed in the thickness direction of the resist pattern. When you do RIE,
The structure according to the gradation of the photomask is transferred to the groove of the Si substrate. If the groove is deep, reduce the substrate temperature during RIE.
By setting the temperature to a low temperature of about 40 ° C. or less, the spread to the side surface can be suppressed. Next, a thermal oxide film 201 having a thickness of about 1 μm is formed on the inner surface of the groove in order to insulate the Si substrate 102 from a fixed electrode 103 to be formed later.

<< FIG. 2 (b) >> A conductive thin film of, for example, TiN is formed by sputtering. The pattern of the fixed electrode 103 is patterned by photolithography of an organic resist, and the conductive thin film is etched by RIE with Cl2 gas to form the fixed electrode 103. Then, a SiN film to be the passivation film 104 is formed by thermal CVD of a mixed gas of SiH4 and NH3.

<< FIG. 2 (c) >> Oxide film 20 serving as a sacrificial layer
2 is formed by thermal CVD of a mixed gas of PH3, B2H2, SiH4 and N2O. Then, a reflow process is performed at 1000 ° C. to make the surface flat, and further, the surface is polished and flattened by a CMP (Chemical Mechanical Polishing) technique.

<< FIG. 2 (d) >> The SiN film 203 to be the beam 101 by thermal CVD of a mixed gas of SiH4 and NH3.
Is formed.

<< FIGS. 3A and 3B >> The planar shape of the beam 101 is patterned by photolithography of an organic resist, and the SiN film 203 is etched by RIE of CHF 3 to manufacture the shape of the beam 101. The sacrificial layer buried in the void is exposed by the slit 204 for etching.
At the same time, the electrode pad 108 of the fixed electrode 103 is also opened.
A metal thin film serving as a mirror material, for example, a Cr film is formed by a sputtering method, an organic resist is patterned by photolithography, and etched by RIE of a mixed gas of Cl2 and O2 to form a metal film 106 serving as a light reflecting surface. I do.

<< FIGS. 4A and 4B >> The sacrificial layer oxide film 202 is removed by etching through a slit 204 using hydrofluoric acid. The void 105 is completed by removing the sacrificial layer.

Next, the manufacturing process of the package upper lid will be described. Here, an organic EL element is used as the light emitting element 304.

<< FIG. 5 (a) >> First, a convex portion 303 is formed on a transparent glass substrate as the package upper lid 302. As described above, the convex portion 303 has a semi-cylindrical shape that is long in the long side direction of the light emitting element, but may have a spherical shape. Specifically, a glass substrate in which square holes corresponding to the extraction electrode pads (107, 108) are formed by bead blasting, a photoresist is applied to the glass substrate, and a gradation corresponding to the convex portion 303 is formed. A photoresist pattern is formed using a photomask having. Then, the glass substrate is etched by inductively coupled RIE using a mixed gas of CF4, CHF3 and H2 to form a convex portion 303.

<< FIG. 5 (b) >> A light-shielding film 306 is formed. For example, a Cr film is formed to a thickness of 100 nm on the back surface of a glass substrate by a vacuum evaporation method, an organic resist is patterned by photolithography, and the Cr film is etched with a mixed aqueous solution of cerium acetate and perchloric acid. Then, the resist is removed with a stripping solution.

<< FIG. 5 (c) >> Next, an organic EL element as the light emitting element 304 is formed. FIG. 7 shows a film configuration of this organic EL element. FIG. 7A illustrates a cross-sectional structure viewed from the left side in FIG. 5, and FIG. 7A illustrates a cross-sectional structure viewed from the front. First, a transparent electrode film (ITO) having a thickness of 100 nm is formed by a sputtering method using an ITO target. An organic resist is patterned thereon by photolithography, the transparent electrode film is etched with an aqueous ferric chloride solution, and the resist is removed with a resist stripper to form a transparent electrode (ITO) 304a. A metal mask is mounted, and a hole transport layer 304b, an electron transport layer 304c, and a metal electrode 304d are sequentially formed on the transparent electrode 403a.
For example, as the hole transport layer 304b, TPD; N, N'-diphenyl-, N'-bis- (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine is resistance-heated. 55nm by vacuum evaporation
To a thickness of Next, as the electron transport layer 304c, A
lq; tris (8-quinolinol) aluminum is deposited to a thickness of 55 nm by resistance heating vacuum evaporation. Next, the metal electrode 4
As 03d, an alloy of Mg and In is vacuum-deposited to a thickness of 150 nm. Next, a pad electrode 305 is formed by depositing an Al thin film to a thickness of 500 nm by an evaporation method using a metal mask. Next, a film of a SiN or SiON film is formed as a protective film 307 by a plasma CVD method. Then, an organic resist is formed by photolithography, and the protective film 3 is formed by RIE.
07, a pad opening is formed.

As a material of the hole transport layer 304b,
Hydrazones, triphenylmethanes, polyvinylcarbazoles, pyrazolines, and the like may be used. As a material for the electron transport layer 304c, a cyclopentadiene derivative, a perylene derivative, a beryllium-benzoquinolinol complex, a quinolinol complex, a porphyrin complex, or the like can be used.

<< FIG. 5 (d), (e) >> Spacer 301
Are separately manufactured, and the package upper lid 304 is bonded to the substrate 102 via the spacer 301 using, for example, an epoxy-based adhesive to complete the light modulation device.

Although the process of preparing one package of the light modulator has been described above, a method of actually assembling a plurality of packages on a wafer and separating the individual packages later is adopted. This will be described with reference to FIG.

A package upper cover 302 for a plurality of cages is prepared by forming square holes corresponding to the lead electrode pads (107, 108) on a glass substrate by bead blasting and forming light emitting elements and the like by the above-described steps. I do. Further, holes are formed in the glass plate by electric discharge machining or bead blasting, and spacers 301 for a plurality of packages are prepared. A spacer formed by punching or etching a square hole corresponding to the chip size in a stainless steel or Kovar plate can also be used. Alternatively, the spacer 301 can be formed by anisotropically etching a single crystal Si substrate with a KOH aqueous solution. Similarly, a substrate 1 for a plurality of packages having electrodes and the like as described above.
02 is formed on a Si wafer. Then, after joining these members as shown in FIG. 6A, dicing is performed as shown in FIG. 6B, and separated into individual packages as shown in FIG. 6C.

Embodiment 2 FIG. 8 is a schematic sectional view for explaining the structure of another embodiment of the light modulator of the present invention.
(A) shows a non-driving state, and (b) shows a driving state. In FIG. 8, the same reference numerals as those in FIG. 1 indicate the same or corresponding elements.

The difference between the second embodiment and the first embodiment is that the light emitting element 304 is formed on the substrate 102, the downward mirror 311 is formed on the package upper cover 302, and the light emitted from the light emitting element 304. Is reflected to the beam 101 by the mirror 311. In the second embodiment, the mirror 311 is a concave mirror in order to efficiently collect light on the beam 101. Although the beam 101 is a fixed beam at both ends, it can be a fixed beam at one end.

Each beam 101 is flat when a drive voltage is not applied to its electrode pad 107. Therefore, as shown in FIG. 8A, the light incident from the mirror 311 is the light on the beam. The light is reflected by the reflection surface in the direction of the window 313 of the light-shielding film 306 and output to the outside. When a driving voltage is applied to the electrode pad 107 of a certain beam 101, the beam 101 is attracted to the fixed electrode 103 side, and is reflected by the light reflecting surface on the beam 101 as shown in FIG. 8B. The light is blocked by the light shielding film 306 and is not output to the outside.

The beam 101, the light emitting element 304, the mirror 31
By selecting the positional relationship 1, light can be output outside the package in the non-driving state, and can be prevented from being output in the driving state.

Next, the manufacturing process of the second embodiment will be described with reference to FIG.
This will be described with reference to FIGS.

<< FIG. 9 (a) >> A groove serving as a void is pattern-formed on the Si substrate 102 with an organic photoresist. For example, a groove is dug by dry etching with RIE of SF6 gas. When forming an inclination in the groove, a gradation is provided on the photomask, and the inclination is formed in the thickness direction of the resist pattern. R
When the IE is performed, the structure according to the gradation of the photomask is transferred to the groove of the Si substrate. If the groove is deep, the spread to the side surface can be suppressed by setting the substrate temperature to a low temperature of about −40 ° C. or less during RIE. Next, in order to insulate the Si substrate 102 from the fixed electrode 103 to be formed later, 1 μm
A thermal oxide film 201 is formed to a thickness of about m.

<< FIG. 9 (b) >> A conductive thin film of, for example, TiN is formed by a sputtering method. The pattern of the fixed electrode 103 is patterned by photolithography of an organic resist, and the conductive thin film is etched by RIE with Cl2 gas to form the fixed electrode 103. Then, a SiN film to be the passivation film 104 is formed by thermal CVD of a mixed gas of SiH4 and NH3.

<< FIG. 9 (c) >> Oxide film 20 serving as a sacrificial layer
2 is formed by thermal CVD of a mixed gas of PH3, B2H2, SiH4 and N2O. Then, a reflow process is performed at 1000 ° C. to make the surface flat, and further, the surface is polished and flattened by a CMP (Chemical Mechanical Polishing) technique.

<< FIG. 9 (d) >> The SiN film 203 to be the beam 101 by thermal CVD of a mixed gas of SiH4 and NH3.
Is formed.

<< FIGS. 10 (a) and 10 (b) >> The planar shape of the beam 101 is patterned by photolithography of an organic resist, and the SiN film 203 is etched by RIE of CHF 3 to produce the shape of the beam 101. The sacrificial layer buried in the void is exposed by the slit 204 for etching. At the same time, the electrode pad 108 of the fixed electrode 103 is also opened. A metal thin film serving as a mirror material, for example, a Cr film is formed by a sputtering method, an organic resist is patterned by photolithography, and etched by RIE of a mixed gas of Cl2 and O2 to form a metal film 106 serving as a light reflecting surface. I do.

<< FIGS. 10 (c) and 10 (d) >> The sacrificial layer oxide film 202 is removed by etching through the slit 204 using hydrofluoric acid. The void 105 is completed by removing the sacrificial layer.

<< FIG. 11 (a), (b) >> Next, an organic EL element as the light emitting element 304 is formed. First, a metal mask is attached, and the Mg-In alloy
Vacuum deposited to a thickness of 0 nm. Wear a metal mask,
Alq as a hole transport layer is 55 nm by resistance heating vacuum evaporation
To a thickness of Next, as an electron transport layer, TPD is continuously formed to a thickness of 55 nm by resistance heating vacuum evaporation.
Further, as the transparent conductive film 402, ITO is formed at room temperature by ion-assisted vapor deposition. A using a metal mask
is vacuum-deposited to a thickness of 500 nm to form an electrode pad 312.
To form

Next, the manufacturing process of the package lid will be described.

<< FIG. 11 (c) >> Package upper lid 302
As described with reference to FIG. 6, a glass substrate in which square holes corresponding to the extraction electrode pads are formed by bead blasting is manufactured. A photoresist is applied to the glass substrate, and a photoresist pattern is formed using a photomask having a gradation corresponding to the concave shape 311a. Using a mixed gas of CF4, CHF3 and H2,
The glass substrate is etched by inductively coupled RIE to form a concave surface 311a.

<< FIG. 11D >> A reflection film and a light-shielding film 306 of the concave mirror 311 are formed. For example, Cr is deposited to a thickness of 100 nm by a sputtering method. The organic resist is patterned into the shape of the concave mirror 311 and the light-shielding film 306 by photolithography, the Cr film is etched with a mixed aqueous solution of cerium acetate and perchloric acid, and the resist is removed with a stripping solution.

<< FIG. 11 (e), (f) >> Spacer 30
Prepare 1 separately. As described with reference to FIG. 6, the spacer 301 can be manufactured by forming a hole in a glass substrate by electric discharge machining or bead blasting. The spacer 301 can also be manufactured by forming a square hole corresponding to the chip size in a stainless steel plate or a Kovar plate by punching or etching. Alternatively, it is also possible to form the spacer 301 by anisotropically etching the single crystal si substrate with a KOH aqueous solution. Then, the spacer 301 is attached to the substrate 102.
The optical modulator is completed by, for example, bonding with an epoxy adhesive so as to be sandwiched between the package and the package upper lid 302. Actually, as described in the first embodiment, the light modulation devices for a plurality of packages are formed on a wafer, and are separated into individual packages by dicing.

<< Embodiment 3 >> FIGS. 12A and 12B are schematic cross-sectional views for explaining the configuration of another embodiment of the light modulation device of the present invention. FIG. 12A shows a non-driving state, and FIG. Is represented. In FIG. 12, the same reference numerals as those in FIG. 1 indicate the same or corresponding elements.

The difference between the third embodiment and the first embodiment is that the light emitting element 304 is formed on the substrate 102 and the waveguide 210 b for guiding the light emitted from the light emitting element 304 to the gap 105. Is formed on the substrate 102 and the beam 10
1 has a hole 10 for passing the light guided to the waveguide 210b.
1b is formed. Although the beam 101 is a fixed beam at both ends, it can be a fixed beam at one end.

Each beam 101 is in a flat state when no drive voltage is applied to its electrode pad 107. Therefore, as shown in FIG. 12A, the light guided from the waveguide 201b is a fixed electrode. The light 103 is reflected toward the beam 101 and is shielded from light by the metal film 106 on the beam 101, so that the light is not output from the window 313 of the light-shielding film 306 to the outside.
When a drive voltage is applied to the electrode pad 107 of a certain beam 101, the beam 101 is attracted to the fixed electrode 103 side, so that the light guided to the gap 105 by the waveguide 201b as shown in FIG. The light passes through the hole 101b of the beam 101, is reflected by the metal film 106 on the beam 101 in the direction of the window 313, and is output to the outside.

Next, the manufacturing process of the third embodiment will be described with reference to FIG.
This will be described with reference to FIGS. << FIG. 13 (a) >> The Si substrate 102 is thermally oxidized to 1 μm
A thermal oxide film having a thickness is formed. As a core layer of the waveguide 201b, an SiN film is formed to a thickness of 5.2 μm by a plasma CVD method using a mixed gas of SiH4 and NH3 at a substrate temperature of 300 ° C. Next, a groove serving as a void is patterned with an organic photoresist. For example, a groove is formed by dry etching with an inductively coupled RIE using a mixed gas of CF4 and H2.
When forming an inclination in the groove, a gradation is provided on the photomask,
An inclination is formed in the thickness direction of the resist pattern. RIE
Is performed, the structure according to the gradation of the photomask becomes Si
It is transferred to the groove of the N layer.

<< FIG. 13 (b) >> A conductive thin film such as TiN is formed by sputtering. The pattern of the fixed electrode 103 is patterned by photolithography of an organic resist, and the conductive thin film is etched by RIE with Cl2 gas to form the fixed electrode 103. Then, a SiN film to be the passivation film 104 is formed by thermal CVD of a mixed gas of SiH4 and NH3.

<< FIG. 13 (c) >> Oxide film 2 serving as a sacrificial layer
02 is formed by thermal CVD of a mixed gas of PH3, B2H2, SiH4 and N2O. Then, a reflow process is performed at 1000 ° C. to make the surface flat, and further, the surface is polished and flattened by a CMP (Chemical Mechanical Polishing) technique.

<< FIG. 13 (d) >> The SiN film 20 serving as the beam 101 is formed by thermal CVD of a mixed gas of SiH4 and NH3.
3 is formed.

<< FIGS. 14A and 14B >> The planar shape of the beam 101 is patterned by photolithography of an organic resist, and the SiN film 203 is etched by RIE of CHF 3 to form the shape of the beam 101. Hole 1 in beam 101
01b is also formed. The sacrificial layer buried in the void is exposed by the slit 204 for etching. At the same time, the electrode pad 108 of the fixed electrode is also opened. Mirror material, for example C
An r film is formed by sputtering, an organic resist is patterned by photolithography, etched by RIE of a mixed gas of Cl2 and O2, and a metal film 106 on a beam as a mirror is formed.
To form

<< FIGS. 14 (c) and 14 (d) >> The sacrificial layer oxide film is removed by etching through the slit 204 using hydrofluoric acid. The space 105 under the beam is completed.

<< FIG. 15 >> In order to form the light emitting element 304, a metal mask is attached and the transparent conductive film 402 (IT
O) is formed to a thickness of 100 nm by a sputtering method. Next, TPD was used as a hole transport layer by resistance heating vacuum evaporation to form a hole transport layer.
A film is formed to a thickness of nm. Alq is continuously formed as an electron transport layer to a thickness of 55 nm by resistance heating vacuum evaporation. As a metal electrode 401, an alloy of Mg and In is further vacuum-deposited continuously to a thickness of 150 nm. Using a metal mask, Al is vacuum-deposited to a thickness of 500 nm to form an electrode pad 312.
To form

<< FIGS. 15 (c), (d), (e) >> On the back surface of the glass substrate as the package upper lid 302, for example, a Cr film is formed to a thickness of 100 nm by sputtering. The organic resist is patterned by photolithography, etched with a mixed aqueous solution of cerium acetate and perchloric acid, and the resist is removed with a stripping solution, so that a light-shielding film 306 is formed. A window 313 is also formed at the same time. The package upper lid 302 is bonded to the substrate 102 via a spacer 301 formed in the same manner as in the above embodiment, for example, with an epoxy-based adhesive. As described in the above embodiments, since a plurality of packages are actually formed on a wafer, dicing is performed to divide the packages into individual packages.

[0059]

According to the present invention, there is provided (1) an optical modulator.
As described in 7 to 7, since the optical switch having the beam as the element and the light emitting element as the light source are formed in the same package, the position setting between the light source and the optical switch is unnecessary,
There is no need for a special optical system in the middle, so the space occupied can be saved.In addition, mass productivity can be improved and costs can be reduced, and a large number of optical switches for switching light from a common light source can be densely formed. Since it is easy, it is suitable as an optical writing device in an electrophotographic process, for example. (2) As described in the second aspect, since the beam constituting the optical switch is a fixed beam at both ends, extra vibration is unlikely to occur at the time of restoration, so that the driving can be performed at a higher speed than when using the fixed beam at one end. It is. (3) As described in claim 3,
When the light-emitting element is an electroluminescence element, the light-emitting element can be easily manufactured on a silicon substrate or a glass substrate, and a sufficient amount of light can be secured. (4)
The light emitted from the light emitting element can be efficiently incident on the optical switch by making the light emitting element face the beam. (5) By forming a convex portion or a concave mirror for condensing light on the package upper lid as described in claim 5 or 6, light from the light emitting element can be more efficiently incident on the optical switch. (6) As described in claim 7, by forming a waveguide on the substrate,
Light from the light emitting element can be efficiently incident on the optical switch. (7) As described in claim 8, by outputting light from the window of the light shielding film formed on the upper cover of the package, the output light can be limited to a predetermined light amount. (8)
Further, according to the driving method of the ninth aspect, it is possible to obtain an effect that unnecessary light output at the time of transition of the optical switch can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view at the time of driving and at the time of non-driving for explaining a first embodiment of an optical modulation device according to the present invention.

FIG. 2 is a schematic cross-sectional view for explaining a manufacturing process of the first embodiment.

FIGS. 3A and 3B are a schematic cross-sectional view and a schematic plan view for explaining a manufacturing process of the first embodiment.

FIGS. 4A and 4B are a schematic cross-sectional view and a schematic plan view illustrating a manufacturing process of the first embodiment.

FIG. 5 is a schematic cross-sectional view for explaining the manufacturing process of the first embodiment.

FIG. 6 is a schematic cross-sectional view for explaining the manufacturing process of the first embodiment.

FIG. 7 is a schematic sectional view illustrating a film configuration of an organic EL element.

FIG. 8 is a schematic cross-sectional view of a light modulation device according to a second embodiment of the present invention when it is driven and when it is not driven.

FIG. 9 is a schematic cross-sectional view for explaining a manufacturing process in Example 2.

FIGS. 10A and 10B are a schematic cross-sectional view and a schematic plan view for explaining a manufacturing process according to a second embodiment.

FIGS. 11A and 11B are a schematic cross-sectional view and a schematic plan view for explaining the manufacturing process of the second embodiment.

FIG. 12 is a schematic cross-sectional view of a light modulation device according to a third embodiment of the present invention when it is driven and when it is not driven.

FIG. 13 is a schematic cross-sectional view for explaining the manufacturing process of the third embodiment.

14A and 14B are a schematic cross-sectional view and a schematic plan view for describing a manufacturing process according to a third embodiment.

FIGS. 15A and 15B are a schematic cross-sectional view and a schematic plan view for explaining the manufacturing process of the third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Beam 102 Substrate 103 Fixed electrode 105 Air gap 106 Metal film (light reflection surface) 301 Spacer 302 Package top lid 303 Convex part 304 Light emitting element (EL element) 306 Light shielding film 313 Window

Claims (9)

[Claims] 1. A fixed electrode, a beam having a light-reflecting surface facing the fixed electrode via a gap, and a light-emitting element are formed in the same package, and the beam is fixed by electrostatic force during driving. The electrode is deformably held on the electrode side, and light generated by the light emitting element is reflected in a different direction by the reflection surface on the beam when the beam is driven and when the beam is not driven. A light modulation device wherein light reflected by a surface is output to the outside of a package. 2. An optical modulator according to claim 1, wherein said beam is a beam fixed at both ends. 3. The light modulation device according to claim 1, wherein the light emitting element is an electroluminescence element. 4. The light emitting device according to claim 1, wherein the fixed electrode and the beam are formed on the same substrate, and the light emitting device is formed on a package upper lid joined to the substrate so as to face the beam. Light modulator. 5. The light modulation device according to claim 4, wherein a convex portion for condensing the light generated by the light emitting element on the beam is formed on the upper cover of the package. 6. The fixed electrode, the beam and the light emitting element are formed on the same substrate, and a concave mirror for condensing light generated by the light emitting element to the beam is provided on a package upper lid joined to the substrate. 2. The method of claim 1, wherein
An optical modulator according to any of the preceding claims. 7. The fixed electrode, the beam and the light emitting element are formed on the same substrate, and a waveguide for guiding light generated by the light emitting element to the gap is formed in the substrate. The light modulation device according to claim 1, wherein 8. A light-shielding film is formed on the package upper cover, and light reflected on a light reflecting surface on the beam is output to the outside of the package through a window provided in the light-shielding film. 2. The light modulation device according to 1. 9. The light-emitting device according to claim 1, wherein the light-emitting element does not emit light during the beam displacement process.
The driving method of the light modulation device according to the above.