JP2006091666A - Transmission type optical modulation array device and optical device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a high quality image and improve a degree of design freedom and reliability without inviting upsizing and cost increase due to complication of an optical system. <P>SOLUTION: An optical path of the light that is driven according to an input signal and is made incident and transmitted there-through is provided with a transmission type optical modulation array element 101 polarizable for each pixel. An optical path isolating prism 103 comprising a total reflection interface 103c is arranged on an exit light side of the light in the transmission type optical deflection array element 101. The exit light whose optical path is deflected by the transmission type optical deflection array element 101 is separated into transmitted light passing through the total reflection interface 103c and reflected light reflected by the total reflection interface 103c. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transmissive light modulation array device that has a plurality of pixels arranged one-dimensionally or two-dimensionally and modulates light according to an input signal, and an optical device using the same.

2. Description of the Related Art An optical device that forms an image, such as a projector, includes a system that includes a deflecting unit that is driven according to an input signal and deflects the path of incident light for each pixel. As an optical apparatus provided with this kind of deflecting means, the following is known (see Patent Document 1).
In the apparatus shown in FIG. 22, the light from the light source 1 is guided to the glass load 5 through the color selection means 3 and focused by the lens element 7. Further, the traveling path of this light is converted by the optical path conversion unit 9, and thereafter, image formation is performed by the micromirror device 11 and enlarged projection is performed by the projection lens unit 13. The optical path changing means 9 which is a deflection means of this apparatus transmits an incident light having an angle smaller than a predetermined angle, and changes an optical path by reflecting the incident light having an angle larger than the predetermined angle. 15 and a compensation prism 17 for correcting the optical path.

  In the apparatus shown in FIG. 23, the light from the light source 21 is guided to the collimating lens 25 through the color selection means 23, further uniformed by the uniform light irradiation means 27, and focused by the focusing lens 29, and the micromirror. An image is formed by being guided to the device 31. Thereafter, the light reflected by the micromirror device 31 is converted in its traveling path by the optical path conversion means 33 and enlarged and projected by the light projecting lens unit 35. Then, as shown in an enlarged view in FIG. 24, the optical path changing means 33 which is a deflecting means of this apparatus refracts and transmits incident light having an angle smaller than the total reflection critical angle, while having an angle larger than the total reflection critical angle. A light separation prism 37 that changes the light path by reflecting the incident light, and a compensation prism 39 that is disposed on the front side of the light path of the light separation prism 37 and corrects the light path.

  In addition, as shown in FIG. 25, the micromirror devices 11 and 31 used in the above apparatus have a plurality of movable mirrors 43 provided on the substrate 41 so as to correspond to the pixels, and the movable mirrors 43 are rotatable. It has a post 45 for supporting and a window 47 for holding the movable mirror 43. The movable mirror 43 is driven to tilt by mutual electrostatic attractive force with the electrode formed on the substrate 41. As a result, the movable mirror 43 selects the angle of the reflecting surface according to the ON state or OFF state of the electrode corresponding to each pixel, and the reflected light in the OFF state when the incident light is in the ON state. The structure is divided into useless reflected light that is reflected light.

  Next, another optical device provided with a deflecting means will be described (see Patent Document 2). In this apparatus, as shown in FIG. 26, the light from the light source 51 is reflected by the beam splitter 57 through the lens 53 and the polarizing plate 55 and the spatial light modulator array 61 comprising a micromirror device through the wave plate 59. Lead to. Then, the light incident on the spatial light modulator 61 is divided into useful light in the ON state and unnecessary light in the OFF state and guided to the critical angle prism 63, and only useful light passes through the critical angle prism 63. The light is guided to the screen 67 through the imaging lens 65 and imaged, and the unnecessary light is totally reflected by the critical angle prism 63 and is removed from the path of the display optical system such as the imaging lens 65.

  In addition, as shown in FIG. 27, an apparatus using a plurality of prisms 71 and 73 is known as one that separates incident light according to an incident angle (see Patent Document 3). Then, according to the optical system including the plurality of prisms 71 and 73, for example, whether or not the reflected light from the micromirror device is correctly transmitted or reflected by the respective prisms 71 and 73 and guided to a predetermined path. Investigation and evaluation of micromirror devices can be performed.

As described above, in an optical apparatus that forms an image, a micromirror device is generally used to deflect the direction of reflected light.
As a transmission type optical deflection array element for deflecting incident light when transmitting incident light, an element composed of the following liquid crystal deflection element is known (for example, see Patent Document 4).
This liquid crystal deflecting element has a structure in which a liquid crystal layer is sandwiched between divided electrodes with open windows. By controlling the voltage applied to the divided electrodes, a refractive index distribution is given to the liquid crystal layer and the light beam is deflected by about 10 °. To do. In the case of this element, the deflection direction of each light beam can be controlled.

  As shown in FIGS. 28 and 29, the liquid crystal deflecting element 81 includes a liquid crystal layer 85 between glass substrates 83, and two pairs of upper and lower electrodes 87 are provided for each pixel so as to sandwich the liquid crystal layer 85. ing. In the liquid layer deflecting element 81, when no voltage is applied to the electrode 87, the liquid crystal is homeotropically aligned perpendicular to the substrate 83 as shown in FIG. It passes through as it is. On the other hand, when a voltage is applied to the electrode 87 and the voltage polarity applied to the pair of electrodes 87 is changed to + and-, the orientation distribution of the liquid crystal molecules is changed, thereby changing the refractive index distribution, As shown in FIGS. 29B and 29C, the incident light is deflected.

JP 2001-201716 A Japanese Patent Laid-Open No. 11-249037 JP-A-9-21966 Japanese Patent Laid-Open No. 10-274791

  By the way, any of the above optical devices using a micromirror device reflects and deflects incident light by the micromirror device, that is, the incident light side and the reflected light side are the same side. The surface reflected light becomes so-called stray light and affects image formation. In particular, in the case of the apparatus shown in FIG. 22, since useful light and unnecessary light are guided in substantially the same direction, a reduction in contrast is inevitable.

Here, as in the apparatus shown in FIG. 23, if the path of useful light and useless light is completely separated by a light separation prism having a plurality of total reflection critical surfaces, a decrease in contrast can be prevented. Since this light separation prism has a plurality of total reflection critical surfaces, an increase in size is inevitable, and as a result, the entire optical system is increased in size. Further, an increase in cost due to the provision of this type of light separation prism is inevitable.
In addition, in the above apparatus in which the incident light side from the light source and the reflected light side from the micromirror device are on the same side, the optical system becomes complicated and large in order to improve the optical quality by separating the reflected light And cost increase.

  In addition, when the incident light side and the reflected light side are the same side, it is necessary to make the directions of the useful light and the useless light such as the surface reflection light different in order to emphasize the contrast. It is decided uniquely. That is, it is difficult to freely set the directions of useful light and useless light, and the degree of freedom in design is reduced.

  The present invention has been made in view of the above circumstances, and is a transmissive light with high design freedom and high reliability capable of forming a high-quality image without causing an increase in size and cost due to a complicated optical system. It is an object of the present invention to provide a modulation array device and an optical device using the same.

  In order to achieve the above object, a transmission type light modulation array device according to claim 1, wherein a plurality of pixels are arranged in a one-dimensional or two-dimensional manner, and the transmission light modulates the light emitted from the pixels in accordance with an input signal. A transmissive optical deflection array element capable of deflecting, for each pixel, an optical path of light that is driven according to the input signal and is incident and transmitted therethrough; and A deflection angle separating means arranged on the emission side and separating the outgoing light from the transmissive light deflection array element into an angle wider than a deflection angle range of an optical path by the transmissive light deflection array element; And

  According to this transmissive light modulation array device, the optical path of light incident and transmitted by the transmissive light deflection array element is deflected. Therefore, unlike the reflective type that reflects to the incident side, useless light or stray light consisting of surface reflected light Can reliably prevent the influence on the image formation, greatly improve the quality of the image formation, and improve the reliability. Further, the deflection angle separating means separates the light emitted from the transmissive light deflection array element into an angle wider than the deflection angle range of the optical path by the transmissive light deflection array element, so that there is no increase in size and cost. Good contrast can be obtained, and further, the degree of freedom in designing the optical path can be increased. In addition, the amount of drive in the transmissive optical deflection array element can be reduced to enable control with a slight deflection angle, and the responsiveness can be enhanced. Also, analog gradation can be performed by continuously changing the deflection angle.

  3. The transmissive light modulation array device according to claim 2, wherein the deflection angle separating means includes a first direction and a second direction in which the outgoing light from the transmissive light deflection array element exhibits an angle wider than the deflection angle range. It is characterized by being separated into

  According to this transmissive light modulation array device, useful light and image used for image formation are separated by separating the light emitted from the transmissive light deflection array element into a first direction and a second direction that exhibit a wide angle. It is possible to reliably separate unnecessary light that is not used for formation and improve contrast and design freedom.

  4. The transmission-type light modulation array device according to claim 3, wherein the deflection angle separation means has a total reflection interface at least in part, and transmits light emitted from the transmission-type light deflection array element through the total reflection interface. The transmitted light and the reflected light reflected by the total reflection interface are separated.

  According to this transmissive light modulation array device, the light emitted from the transmissive light deflection array element can be reliably separated into transmitted light that is transmitted through the total reflection interface and reflected light that is reflected at the total reflection interface.

  The transmission type light modulation array apparatus according to claim 4 is characterized in that the deflection angle separation means includes a prism.

  According to this transmissive light modulation array device, useful light and useless light can be reliably separated by the prism.

  6. The transmissive light modulation array device according to claim 5, wherein the deflection angle separation means includes an optical path compensation prism that corrects an optical path difference generated according to an arrangement position of each pixel of the transmissive light deflection array element. Features.

  According to this transmissive light modulation array device, it is possible to reliably correct the optical path between the pixels and to match the optical path reliably, and to improve the image quality.

  7. The transmission type light modulation array device according to claim 6, wherein the deflection angle separation means has an optical interference film at least in part, and introduces outgoing light from the transmission type optical deflection array element into the optical interference film. The introduced light is separated into transmitted light and reflected light.

  According to this transmissive light modulation array device, the light emitted from the transmissive light deflection array element can be reliably separated into transmitted light and reflected light by the optical interference film.

  The transmission type light modulation array device according to claim 7 is characterized in that the optical interference film includes a dielectric multilayer film.

  According to this transmissive light modulation array device, the light emitted from the transmissive light deflection array element can be reliably separated into transmitted light and reflected light by the optical interference film formed by the dielectric multilayer film.

  The transmission type light modulation array device according to an eighth aspect is characterized in that the optical interference film is formed including cholesteric liquid crystal.

  According to this transmissive optical modulation array device, the light emitted from the transmissive optical deflection array element can be reliably separated into transmitted light and reflected light by the optical interference film having cholesteric liquid crystal.

  The transmission type light modulation array device according to claim 9 is characterized in that the optical interference film does not have polarization dependency.

  According to this transmission type light modulation array device, light emitted from the transmission type light deflection array element can be reliably transmitted and reflected while simplifying the configuration by an optical interference film having no polarization dependency. Can be separated.

  The transmissive optical modulation array device according to claim 10 is characterized in that the optical interference film separates only the S wave in the light component into transmitted light and reflected light.

  According to this transmissive light modulation array device, only the S wave of the light emitted from the transmissive light deflection array element can be reliably separated into transmitted light and reflected light by the optical interference film.

  The transmissive light modulation array apparatus according to claim 11 is characterized in that the transmissive light deflection array element is an element that changes a direction of transmitted light by displacing a minute movable film.

  According to this transmissive light modulation array device, the degree of freedom of selection of the wavelength of light that can be controlled is greater than that of a liquid crystal element. An element driven by electrostatic force is excellent in high-speed response, low power consumption, and high integration.

  13. The transmissive light modulation array device according to claim 12, wherein a light incident side of a light deflection element corresponding to each of the pixels driven by the input signal of the transmissive light deflection array element corresponds to each of the pixels. A microlens array in which microlenses are formed is arranged, and a condensing position by the microlens array is set to a deflection driving position of the light deflection element.

  According to this transmission type light modulation array device, incident light can be condensed on the light deflection element of the transmission type light deflection array element by the microlens of the microlens array arranged on the light incident side of the light deflection element. The utilization efficiency of incident light for image formation can be increased, and further, the light deflection element can be reduced in size and weight, and the response of the light deflection element can be improved. In addition, the drive circuit can be arranged in a region other than the condensing portion by the microlens of the microlens array, whereby the degree of integration can be increased and the light shielding means in the drive circuit can be made unnecessary.

  The transmissive light modulation array device according to claim 13, wherein the light deflection element corresponding to each pixel driven by the input signal of the transmissive light deflection array element has a light incident side and an emission side, and each pixel has a light incident side. Correspondingly, microlens arrays each having a microlens are arranged.

According to this transmissive light modulation array device, incident light is condensed on the light deflection element of the transmissive light deflection array element by the microlenses of the microlens array respectively arranged on the light incident side and the emission side of the light deflection element. The efficiency of using incident light for image formation can be increased, and further, the light deflection element can be reduced in size and weight, and the response of the light deflection element can be improved. .
In addition, the drive circuit can be arranged in a region other than the condensing portion by the microlens of the microlens array, whereby the degree of integration can be increased and the light shielding means in the drive circuit can be made unnecessary.

  An optical apparatus using the transmissive light modulation array apparatus according to claim 14 is characterized in that the transmissive light modulation array apparatus is used.

  According to the optical device using this transmission type light modulation array device, the quality of image formation can be greatly improved, and the reliability can be improved. Further, according to this optical device, it is possible to obtain a good contrast without increasing the size and cost, and further, it is possible to increase the degree of freedom in designing the optical path.

  According to the transmissive light modulation array device of the present invention, the light that is incident and transmitted by the transmissive light deflection array element is deflected. Therefore, unlike the reflective type that reflects to the incident side, useless light or stray light composed of surface reflected light. Can reliably prevent the influence on the image formation, greatly improve the quality of the image formation, and improve the reliability. Further, since the deflection angle separating means separates the light emitted from the transmissive light deflection array element into an angle wider than the light deflection angle range by the transmissive light deflection array element, without increasing the size and cost. The degree of freedom in designing the optical path can be increased. In addition, the amount of drive in the transmissive optical deflection array element can be reduced to enable control with a slight deflection angle, and the responsiveness can be enhanced. Further, analog gradation can be controlled by continuously changing the deflection angle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a transmissive light modulation array device and an optical device using the same according to the present invention will be described below in detail with reference to the drawings.
(First embodiment)
First, a first embodiment according to the present invention will be described.
FIG. 1 is a schematic configuration diagram for explaining the basic principle of the transmissive light modulation array device according to the first embodiment, and FIG. 2 is a graph showing the characteristics of the deflection angle separation means constituting the transmissive light modulation array device.

  As shown in FIG. 1, the transmissive light modulation array device 100 includes a transmissive light deflection array element 101. This transmissive light deflection array element 101 has a plurality of pixels two-dimensionally, and when driven according to an input signal to transmit incident light, deflects the light by a minute angle for each pixel. . Here, the transmissive light deflection array element 101 has a structure in which a liquid crystal layer is sandwiched between split electrodes having windows as shown in FIGS. 28 and 29, for example, and the voltage applied to the split electrodes is controlled. As a result, a liquid crystal deflecting element that gives a refractive index distribution to the liquid crystal layer and deflects the optical path of incident light during transmission is used. In addition, the micro transparent optical member (for example, micro prism) described in the patent application (Japanese Patent Application No. 2004-168097) filed by the present inventor is tilted and displaced by electromechanical operation to emit light from the micro transparent optical member. A transmissive optical deflection array element by so-called MEMS (Micro-Electro-Mechanical Systems) is used, such as a transmissive optical modulation array element that changes the light intensity.

  The transmissive light deflection array element 101 includes an optical path separation prism 103 as a deflection angle separation means in front of the optical path. The optical path separation prism 103 separates the light deflected by the transmissive optical deflection array element 101 into transmitted light that transmits the total reflection interface 103a and reflected light that is reflected by the total reflection interface 103a according to the optical path. At the same time, the angle formed between the transmitted light and the reflected light is separated by an angle φ sufficiently larger than the minute deflection angle by the transmissive light deflection array element 101.

Here, as shown in FIG. 2, the optical path separation prism 103 has a characteristic of the total reflection interface 103a that is incident on the normal line N of the total reflection interface 103a through the transmissive optical deflection array element 101. When the incident angle θi of light is greater than or equal to the total reflection critical angle θc of the total reflection interface 103a, the light is totally reflected, and when the incident angle is smaller than the total reflection critical angle θc, the light is transmitted.
That is, the optical path separation prism 103 totally reflects light having an angle θ ₁ greater than or equal to the critical angle θc at the total reflection interface 103a and transmits light having an angle θ ₂ smaller than the critical angle θc through the total reflection interface 103a. .

Further, the transmission type light modulation array device 100 is configured such that an optical path compensation is provided with a sufficient gap (for example, 2λ or more when the wavelength of light is λ) with respect to the total reflection interface 103a of the optical path separation prism 103. A prism 105 is provided.
The optical path compensation prism 105 corrects the optical path generated in each pixel when the light is transmitted through the total reflection interface 103a of the optical path separation prism 103 and emitted to the outside. The light transmitted through the optical path compensation prism 105 The optical path is corrected for each pixel, and when exiting, the respective optical paths are matched.

As described above, according to the transmissive light modulation array device 100, the optical path of the light that is incident and transmitted is deflected by the transmissive light deflection array element 101. Therefore, unlike the reflective type that reflects to the incident side, the surface reflected light is reflected. Therefore, it is possible to surely prevent the influence of unnecessary light and stray light on image formation, and the quality of image formation can be greatly improved and the reliability can be improved.
Further, the optical path separation prism 103 which is a deflection angle separation means separates the light emitted from the transmissive optical deflection array element 101 into an angle wider than the deflection angle range of the optical path by the transmissive optical deflection array element 101, so that the size is increased. Therefore, good contrast can be obtained without increasing the cost, and the degree of freedom in designing the optical path can be increased.

  In addition, the drive amount in the transmissive optical deflection array element 101 can be reduced to enable control with a slight deflection angle, and the responsiveness can be improved. Also, analog gradation can be performed by continuously changing the deflection angle. Furthermore, the optical path compensation prism 105 can surely correct the optical path between the pixels and match the optical path reliably, thereby improving the image quality.

Next, a configuration example of an optical device including the transmissive light modulation array device 100 will be described.
FIG. 3 is a schematic configuration diagram showing an example of the configuration of an optical device provided with a transmissive light modulation array device.
In this optical device 110, light transmitted through the total reflection interface 103a of the optical path separation prism 103 is used as useful light, and light reflected at the total reflection interface 103a is used as unnecessary light.

That is, as shown in FIG. 3, in this optical device 110, useful light that passes through the total reflection interface 103a of the optical path separation prism 103 and whose optical path in the prism is adjusted for each pixel by the optical path compensation prism 105 is imaged. The light is guided to the projection surface 109 via the projection lens 107 to form an image. The useless light reflected by the total reflection interface 103 a of the light separation prism 103 is guided to the light shielding plate 111.
In the optical device 110, when used as an exposure system, an image can be exposed to a photosensitive material disposed on the projection surface 109. When used as a projector, an image is projected on the projection surface 109 such as a screen. Can be displayed.

  According to the optical device 110 provided with the transmissive light modulation array device 100, the quality of image formation can be greatly improved, and the reliability can be improved. Further, good contrast can be obtained without increasing the size and cost, and the degree of freedom in designing the optical path can be increased.

FIG. 4 is a schematic configuration diagram illustrating another configuration example of the optical device including the transmissive light modulation array device.
The optical device 120 uses light reflected by the total reflection interface 103 a as useful light, and uses light transmitted through the total reflection interface 103 a of the optical path separation prism 103 as unnecessary light.

That is, as shown in FIG. 4, in the optical device 120, useful light reflected by the total reflection interface 103 a of the light separation prism 103 is guided to the projection surface 109 via the imaging projection lens 107 and forms an image. Further, useless light transmitted through the total reflection interface 103 a of the optical path separation prism 103 is guided to the light shielding plate 111.
The optical device 120 can also expose an image to a photosensitive material disposed on the projection surface 109 when used as an exposure system, and can also display an image on the projection surface 109 such as a screen when used as a projector. Can be displayed.

And also in the case of the optical apparatus 120 provided with this transmissive | pervious light modulation array apparatus 100, the quality of image formation can be improved significantly and reliability can be improved. Further, good contrast can be obtained without increasing the size and cost, and the degree of freedom in designing the optical path can be increased.
In the optical device 120, the light reflected by the total reflection interface 103a is used as useful light, and the light transmitted through the total reflection interface 103a of the optical path separation prism 103 is used as unnecessary light. Therefore, the total reflection interface 103a of the optical path separation prism 103 is used. The optical paths of useful light that pass through each pixel almost coincide with each other and do not need to be matched, and the optical path compensation prism 105 is not provided.

(Second Embodiment)
Next, a second embodiment according to the present invention will be described.
FIG. 5 is a schematic configuration diagram for explaining a transmissive light modulation array device according to the second embodiment, and FIG. 6 explains the principle of an optical interference film used in the transmissive light modulation array device according to the second embodiment. FIGS. 7 and 8 are graphs showing the characteristics of the optical interference film.

As shown in FIG. 5, this transmissive optical modulation array device 200 has an optical interference film 201 as a deflection angle separation means in front of the optical path of the transmissive optical deflection array element 101.
The optical interference film 201 is installed to be inclined at a predetermined angle with respect to the transmissive optical deflection array element 101. Here, it is inclined at 45 ° with respect to the transmissive light deflection array element 101.

The optical interference film 201 separates light of a predetermined wavelength whose optical path is deflected by the transmissive optical deflection array element 101 into transmitted light that is transmitted according to the optical path and reflected light that is reflected.
As shown in FIG. 6, the optical interference film 201 has a structure in which a dielectric multilayer film 205 is formed on a glass substrate 203. The dielectric multilayer film 205 is composed of titanium oxide (TiO ₂ ) and silicon oxide (SiO ₂ ). ₂ ) and are laminated alternately.

In this embodiment, the multilayer structure of the dielectric multilayer film 205 of titanium oxide and silicon oxide is the film structure shown in Table 1, so that light with a wavelength λ = 520 nm is normal to the dielectric multilayer film 205. When the light is incident at an incident angle θ ₁ = 45 °, the light is reflected, and when the light is incident at an incident angle θ ₂ = 10 °, the light is transmitted.

Further, as shown in FIGS. 7 and 8, the dielectric multilayer film 205 reflects each of the S wave and the P wave of the light component having the wavelength λ = 520 nm at the incident angle θ ₁ = 45 °, and the incident angle It has a characteristic of transmitting at θ ₂ = 10 °.

In the transmissive optical modulation array device 200 including the dielectric multilayer film 205, the light having the wavelength λ = 520 nm transmitted through the transmissive optical deflection array element 101 is incident on the optical interference film 201 at an incident angle θ ₁ = 45 °. This light is totally reflected by the optical interference film 201. Further, when light having a wavelength λ = 520 nm, which is deflected through the transmissive optical deflection array element 101, is incident on the optical interference film 201 at an incident angle θ ₂ = 10 °, this light is transmitted through the optical interference film 201. To do. This characteristic is common to both S and P waves.

  That is, according to the transmissive optical modulation array device 200, the light emitted from the transmissive optical deflection array element 101 can be reliably separated into transmitted light and reflected light by the dielectric multilayer film 205 of the optical interference film 201.

  The light interference film 201 can change the transmission or reflection characteristics according to the incident angle with respect to light of various wavelengths by appropriately changing the film structure of the dielectric multilayer film 205.

Here, an optical interference film having other characteristics will be described.
FIG. 9 is a schematic diagram of an optical system for deflecting only S waves, and FIGS. 10 and 11 are graphs showing characteristics of the optical interference film of FIG.
As shown in FIG. 9, as in the case of the transmissive optical modulation array device 200 shown in FIG. 5, an optical interference film 202 is provided in front of the optical path of the transmissive optical deflection array element 101 as deflection angle separation means. It is. The optical interference film 201 is installed to be inclined at a predetermined angle with respect to the transmissive optical deflection array element 101. Here, it is inclined at 45 ° with respect to the transmissive light deflection array element 101.

The optical interference film 202 is made of a dielectric multilayer film, reflects only the S wave of the light component having the wavelength λ = 520 nm at the incident angle θ ₁ = 52 °, and reflects the S wave (and the P wave) at the incident angle θ ₂ = It has the property of transmitting at 40 °.

That is, in the transmissive optical modulation array apparatus provided with the optical interference film 202, for example, when the light component of only the S wave is modulated, the light deflection angle θ ₁ −θ in the transmissive optical deflection array element 101 is used. _{2 is set} to 12 ° (52 ° -40 °).
As shown in FIGS. 10 and 11, the dielectric multilayer film constituting the optical interference film 202 reflects each of the S wave and the P wave of the light component having the wavelength λ = 520 nm at an incident angle θ ₁ = 45 °. And has a characteristic of transmitting at an incident angle θ ₂ = 10 °.
The polarization-dependent dielectric multilayer film can be obtained by setting the film structure as shown in Table 2.

  The transmissive light modulation array device can be applied to a uniaxially polarized laser light source or a non-polarized light source such as a discharge lamp. According to this transmissive light modulation array device, the deflection angle in the transmissive light modulation array element can be made smaller, so that the drive amount is small and high-speed response is possible. In addition, the tolerance required for the optical system can be increased, and the cost can be reduced.

(Third embodiment)
Next, a third embodiment according to the present invention will be described.
FIG. 12 is a schematic configuration diagram for explaining a cholesteric liquid crystal device used in the transmissive light modulation array device according to the third embodiment, and FIG. 13 is a liquid crystal used in the transmissive light modulation array device according to the third embodiment. FIG. 14 is a graph showing the characteristics of the liquid crystal device.

FIG. 12 shows a cholesteric liquid crystal filter 300 installed as a deflection angle separation means in front of the optical path of the transmissive light deflection array element 101.
The cholesteric liquid crystal filter 300 includes a pair of transparent electrodes 301 made of ITO or the like, an alignment layer 303 formed inside thereof, and a cholesteric liquid crystal layer 305 surrounded by the alignment layer 303.

The cholesteric liquid crystal layer 305 has a spiral structure in which cholesteric liquid crystal molecules are aligned parallel to the layer and perpendicular to the layer.
Here, when the ordinary light refractive index of the cholesteric liquid crystal layer 305 is no, the extraordinary light refractive index is ne, the birefringence index is Δn, and the average refractive index is n, the birefringence index Δn can be expressed by equation (1).

Δn = ne−no (1)
Further, the average refractive index n can be approximately expressed by the equation (2).
n = (ne + no) / 2 (2)

Further, when the spiral pitch of the cholesteric liquid crystal layer 305 is P [nm], the cholesteric liquid crystal layer 305 exhibits a characteristic of selectively reflecting on the principle of Bragg reflection. That is, the center wavelength λ (θ) [nm] of the incident light when the light incident on the cholesteric liquid crystal layer 305 at the incident angle θ [deg] is selectively reflected can be expressed by Equation (3).
λ (θ) = λ (0) · cos [sin ⁻¹ (sin θ / n)] (3)

However, incident light is assumed to be incident from air (refractive index = 1). Here, λ (0) [nm] is an incident angle θ, that is, a center wavelength when perpendicularly incident on the layer, and can be expressed by Expression (4).
λ (0) = n · P (4)
Also, the reflection wavelength width Δλ [nm] can be expressed by equation (5).
Δλ = Δn · P (5)

Therefore, by forming the layer by controlling the ordinary light refractive index no, the extraordinary light refractive index ne, and the helical pitch P, which are physical properties of the cholesteric liquid crystal layer 305, an arbitrary reflection center wavelength λ that changes according to the incident angle θ. An optical filter having (θ) and a desired reflection wavelength width Δλ can be formed. For example, the spiral pitch P can be adjusted by a manufacturing method such as mixing and adjusting two or more materials having different spiral pitches.
Furthermore, when the wavelength range of the incident light to be processed is wide, it is necessary to widen the selective reflection wavelength range of the cholesteric liquid crystal layer 305 as well. In this case, the reflection wavelength region can be widened by aligning the liquid crystal so that the helical pitch is continuously different in the thickness direction. Further, the reflection wavelength range can be expanded by stacking cholesteric liquid crystal layers 305 having different selective reflection wavelength ranges.

The cholesteric liquid crystal layer 305 can be manufactured as follows.
A polyimide alignment film is applied on a support on which a cholesteric liquid crystal is formed, dried, and subjected to surface treatment by rubbing. Thereby, a polyimide alignment film is formed. On top of this, a low molecular weight cholesteric liquid crystal, or a mixture of a nematic liquid crystal and a chiral agent that develops twist, a polymer monomer, and a photopolymerization initiator mixed with an organic solvent are applied and then aligned at an appropriate temperature. . Thereafter, the necessary portions are exposed to ultraviolet light for photopolymerization, and unnecessary portions are removed by development. Finally, heat bake to stabilize.
In order to control the twist direction and the reflection incident angle, the cholesteric liquid crystal, the chiral agent, and the respective concentrations may be appropriately changed.

  It is also possible to form a film using a polymer cholesteric liquid crystal. In this case, as described above, a polymer cholesteric liquid crystal and a photopolymerization initiator are coated on a polyimide alignment film with an adjustment solution mixed with an organic solvent, and then aligned at an appropriate temperature, and ultraviolet rays are exposed to necessary portions. And photopolymerized. The reflection incident angle can be controlled by appropriately selecting the alignment temperature, and is stabilized by photopolymerization.

Here, the characteristics of the cholesteric liquid crystal filter 300 having this configuration will be described with reference to FIGS.
The cholesteric liquid crystal layer 305 (see FIG. 12) is an example in which a left-handed cholesteric liquid crystal layer and a right-handed twisted liquid crystal layer are overlapped, and reflects all polarized components in the reflection wavelength region. When the incident angle is from θ ₀ to θ ₁ , the spectral transmittance is approximately 0% with respect to the wavelength λ of the incident light (for example, λ = 520 nm), and the light is reflected, but the angle θ is larger. _{At 2} and θ ₃ , the incident light is transmitted because the transmission characteristic of the spectral transmittance is shifted to the short wavelength side.
In other words, by appropriately arranging the cholesteric liquid crystal filter 300 described above as a transmission type optical deflection array device on the emission side of the transmission type optical deflection array element, the outgoing light from the transmission type optical deflection array element has an angle with respect to the cholesteric liquid crystal filter. When it is incident at θ ₁ or less, it is reflected by the cholesteric liquid crystal filter, and when the light emitted from the transmissive light deflection array element is incident on the cholesteric liquid crystal filter at an angle θ ₂ or more, it is transmitted through the cholesteric liquid crystal filter. Accordingly, it is possible to separate the light emitted from the transmissive deflection array element into transmitted light and reflected light.

  According to this configuration, the same effect as the above-described deflection angle separation means can be obtained, and film formation can be performed by a coating method or the like. It is possible to realize a deflection angle separation unit that reliably separates the reflected light.

(Fourth embodiment)
Next, a transmissive light modulation array device provided with a microlens array will be described as a fourth embodiment.
FIG. 15 is a schematic configuration diagram showing a transmissive light modulation array device according to the fourth embodiment, and FIG. 16 is a schematic configuration diagram enlarging a main part of the transmissive light modulation array device.
As shown in the figure, in the transmissive light modulation array device 400, a microlens array 401 is disposed on the light incident side of the transmissive deflection array element 101. The microlens array 401 has a plurality of microlenses 403 corresponding to the respective pixels of the transmissive deflection array element 101.

Here, as shown in FIG. 16, the transmissive light deflection array element 101 is a so-called MEMS that changes the light emission direction from a minute transparent optical member by, for example, tilting and displacing the aforementioned minute prism by an electromechanical operation. A transmissive light modulation array element of the type is preferably used. The transmissive light modulation array element 101 includes an element substrate 101a and a counter substrate 101b, and includes a light deflection element 101c for each pixel between the element substrate 101a and the counter substrate 101b.
The microlens array 401 condenses incident light on each light deflection element 101 c of the transmissive light deflection array element 101 by each microlens 403. As a result, the degree of integration can be increased and the light shielding means in the drive circuit can be made unnecessary.

  By providing the microlens array 401, incident light is collected on the light deflection element 101c of the transmissive light deflection array element 101 by the microlens 403 of the microlens array 401 arranged on the light incident side of the light deflection element 101c. Light can be used, the use efficiency of incident light for image formation can be increased, and further, the light deflection element 101c can be reduced in size and weight, whereby the response of the light deflection element 101c is improved. Can be increased.

In addition, the drive circuit can be arranged in a region other than the condensing portion by the microlens 403 of the microlens array 401. This can increase the degree of integration and eliminate the need for light shielding means in the drive circuit. it can.
Note that the arrangement position of the microlens array 401 may be any place as long as it is on the incident side of the light deflection element 101c.

FIG. 17 and FIG. 18 show a transmissive light modulation array device 410 having a plurality of microlens arrays 401.
As shown in FIG. 18, the transmissive light modulation array device 410 includes an incident-side microlens array 401a on the incident side of the element substrate 101a of the transmissive deflection array element 101, and is emitted to the incident side of the counter substrate 101b. A side microlens array 401b is provided.

In this transmissive light modulation array device 410, the incident side microlens array 401 a condenses incident light on each light deflection element 101 c of the transmissive light deflection array element 101 by each microlens 403.
Further, the emission-side microlens array 401b further collects the light emitted from each light deflection element 101c by each microlens 403 and emits it to the counter substrate 101b.

  As a result, this transmission type optical deflection array element 101 eliminates the problem that incident light is blocked by, for example, a CMOS or an electrode provided on the element substrate 101a for driving the optical deflection element 101c. Then, the light from the light deflection element 101c is condensed and spread to be substantially parallel light, and is emitted to the deflection angle separation means such as the optical path separation prism 103 on the downstream side. The degree of freedom in designing the image system can be improved.

  The arrangement position of the incident side microlens array 401a may be any position as long as it is on the incident side of the light deflection element 101c, and the arrangement position of the emission side microlens array 401b is the light deflection element 101c. Any location may be used as long as it is on the emission side.

(Fifth embodiment)
Next, an optical apparatus that employs the transmissive light modulation array device according to the above embodiment will be described as a fifth embodiment.
FIG. 19 is a block diagram of an exposure apparatus according to the fifth embodiment using a transmissive light deflection array element, FIG. 20 is a block diagram of the exposure apparatus, and FIG. 21 is a block diagram of an exposure head.
The above-described transmission type light modulation array element can be suitably used, for example, in an exposure apparatus 500 shown in FIG. In this case, the transmissive light modulation array element can be configured, for example, by providing the transmissive light modulation element 100 with a microlens array 401a and the like. The exposure apparatus 500 includes a drum 503 that holds the exposure object 501 on the outer peripheral surface and a sub-scanning unit 507 that is movably supported by a guide shaft 505 that extends along the rotation axis of the drum 503. Provided as a basic configuration. The drum 503 is rotated counterclockwise in FIG. 19 by a rotary drive motor (not shown). The sub-scanning unit 507 is moved in the left-right direction in FIG. 19 by a horizontal drive motor (not shown). Here, in the exposure object 501, the D direction due to the rotation of the drum 503 is the main scanning direction, and the L direction due to the movement of the sub scanning unit 507 is the sub scanning direction.

  As shown in FIG. 19, the sub-scanning unit 507 includes a transmissive light deflection array device 509 and an imaging lens system 511. The rotation position of the drum 503 is detected by the main scanning position detector 513, and the movement position of the sub scanning unit 507 is detected by the sub scanning position detector 515. The position signals detected by the main scanning position detector 513 and the sub-scanning position detector 515 are input to the signal generator 517. Based on these position signals, the signal generator 517 outputs a modulation signal and a light source signal to the transmissive optical deflection array device 509 in accordance with the image signal sent from the host controller. The imaging lens system 511 includes combination zoom lenses 511a and 511b that form an image of the laser light modulated and emitted from the transmissive light deflection array device 509 on the surface of the exposure object 501 by changing the magnification.

  In the transmissive light deflection array device 509, a plurality of transmissive light deflection array elements 101 are arranged in the sub-scanning direction. Therefore, when the exposure object 501 and the sub-scanning unit 507 are relatively moved in a direction (main scanning direction) perpendicular to the arrangement direction, one line is obtained with the same number of pixels as the arrangement number of the transmissive light deflection array elements 101. Minutes can be exposed in the same direction of the exposure object 501.

  As the exposure object 501 moves in the main scanning direction, an image signal for one line is sent to the transmissive light deflection array element 101 as a modulation signal and a light source signal, and each transmissive light deflection array element 101 is controlled on and off. The As a result, the exposure light emitted from the sub-scanning unit 507 is turned on and off, and the exposure object 501 is exposed in the main scanning direction in the same number of pixels as the number of the transmissive light deflection array elements 101 and scanned for one line. Exposure is performed. Thereafter, the sub-scanning unit 507 is moved in the sub-scanning direction, and similarly, the next one line is sequentially exposed.

  By the way, as shown in FIG. 21, the transmissive optical deflection array device 509 transmits a transmissive optical deflection array element 101 that deflects light from a light source, and the outgoing light from the transmissive optical deflection array element 101. A transmission-type light modulation array device 110 having an optical path separation prism 103 that emits light with an angle separated from the deflection angle range of the deflection array element 101 and an optical path compensation prism 105 is provided.

The light transmitted through the transmissive light deflection array element 101 enters the optical path separation prism 103, and the optical path separation prism 103 determines the light path separation prism according to the incident angle of the light emitted from the transmissive light deflection array element 101. The light is separated into useful light that passes through the total reflection interface 103a and useless light that is totally reflected at the total reflection interface 103a.
Thereafter, the useful light transmitted through the total reflection interface 103 a is emitted after the optical path is adjusted for each pixel by the optical path compensation prism 105.
The light thus modulated is irradiated onto the exposure object 501 by the imaging lens system 511. Therefore, exposure or image recording can be performed by exposing the exposure object 501 through the imaging lens system 511 and recording an image.
The useless light reflected by the total reflection interface 103 a of the light separation prism 103 is guided to the light shielding plate 111.

  According to this exposure apparatus 500, since the light deflection array element is a transmissive type, generation of stray light, surface reflected light, etc. in the light deflection array element is suppressed, and only useful light is separated by the optical path separation prism. Since the unwanted light is guided to the exposure object 501 and is shielded, high-contrast exposure can be obtained. Furthermore, since the optical deflection array element is a transmissive type, the optical system on the incident side and the optical system on the outgoing side can be arranged on different sides, so that the size, complexity, and cost of the optical system can be suppressed, and the optical path can be reduced. Design freedom can be increased.

  Further, the exposure object 501 may be a screen in addition to the recording medium held on the drum 503. In this case, if the transmissive light deflection array element 101 is driven and controlled according to the image signal, and the light transmitted through the transmissive light deflection array element 101 is projected onto the screen via the projection lens, the transmissive light modulation array element is obtained. A projector using 101 is obtained.

In the exposure apparatus 500, the optical apparatus 110 including the transmission type light modulation array apparatus shown in the first embodiment is used. However, as a transmission type light modulation array apparatus suitable for use in the exposure apparatus, It is not limited to that of the first embodiment.
In the above-described optical device, the light reflected by the total reflection interface 103a may be useful light, and the light transmitted through the total reflection interface 103a of the optical path separation prism 103 may be unnecessary light.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram illustrating a basic principle of a transmissive light modulation array device according to a first embodiment of the present invention. It is a graph which shows the characteristic of the transmissive | pervious optical deflection | deviation array element which comprises a transmissive | pervious optical modulation array apparatus. It is a schematic block diagram which shows one structural example of the optical apparatus provided with the transmissive | pervious light modulation array apparatus. It is a schematic block diagram which shows the other structural example of the optical apparatus provided with the transmissive | pervious light modulation array apparatus. It is a schematic block diagram explaining the transmissive | pervious light modulation array apparatus which concerns on 2nd Embodiment. It is sectional drawing explaining the principle of the optical interference film used for the transmissive | pervious light modulation array apparatus of 2nd Embodiment. It is a graph which shows the characteristic of a light interference film. It is a graph which shows the characteristic of a light interference film. It is the schematic of the optical system which deflects only S wave. It is a graph which shows the characteristic of a light interference film. It is a graph which shows the characteristic of a light interference film. It is a schematic block diagram explaining the liquid crystal device used for the transmissive | pervious light modulation array apparatus which concerns on 3rd Embodiment. It is sectional drawing explaining the principle of the liquid crystal device used for the transmissive | pervious light modulation array apparatus of 3rd Embodiment. It is a graph which shows the characteristic of a liquid crystal device. It is a schematic block diagram which shows the transmissive | pervious light modulation array apparatus which concerns on 4th Embodiment. It is the schematic block diagram which expanded the principal part of the transmissive | pervious light modulation array apparatus. It is a schematic block diagram which shows the transmissive | pervious light modulation array apparatus provided with the several micro lens array. It is the schematic block diagram which expanded the principal part of the transmissive | pervious light modulation array apparatus provided with the several micro lens array. It is a block diagram of the exposure apparatus by 5th Embodiment using the transmissive | pervious optical deflection | deviation array element. It is a block diagram of an exposure apparatus. It is a block diagram of an exposure head. It is a schematic block diagram of the optical apparatus explaining the conventional optical apparatus. It is a schematic block diagram of the optical apparatus explaining the conventional optical apparatus. It is a schematic block diagram explaining the principal part of the optical apparatus of FIG. It is sectional drawing explaining the structure of the conventional micromirror device. It is a schematic block diagram of the optical apparatus explaining the other conventional optical apparatus. It is a schematic block diagram which shows the optical system which test | inspects apparatuses, such as the conventional micromirror device. It is a schematic plan view which shows an example of a transmissive | pervious optical deflection | deviation array element. It is a schematic sectional drawing of a transmissive | pervious optical deflection | deviation array element.

Explanation of symbols

100, 200, 400, 410 Transmission type light modulation array device 101 Transmission type light deflection array element 101c Light deflection element 103 Optical path separation prism (deflection angle separation means)
103c Total reflection interface 105 Optical path compensation prism 110, 120 Optical device 201 Optical interference film (deflection angle separation means)
205 Dielectric multilayer 305 Cholesteric liquid crystal 401 Microlens array 403 Microlens 500 Exposure apparatus (optical apparatus)

Claims (14)

A transmissive light modulation array device in which a plurality of pixels are arranged in a one-dimensional or two-dimensional manner and modulates light emitted from the pixels in accordance with an input signal,
A transmission type optical deflection array element capable of deflecting for each pixel an optical path of light that is driven according to the input signal and is incident and transmitted;
A deflection which is arranged on the light emission side of the transmissive light deflection array element and separates the emitted light from the transmissive light deflection array element into an angle wider than the deflection angle range of the optical path by the transmissive light deflection array element. A transmission type light modulation array device comprising an angle separating means.   2. The deflection angle separating unit separates light emitted from the transmissive light deflection array element into a first direction and a second direction that exhibit an angle wider than the deflection angle range. Transmission type light modulation array device.   The deflection angle separation means has a total reflection interface at least in part, and transmits the light emitted from the transmissive light deflection array element through the total reflection interface and the reflected light reflected at the total reflection interface. 3. The transmission type light modulation array device according to claim 1, wherein the transmission type light modulation array device is separated.   4. The transmission type light modulation array device according to claim 1, wherein the deflection angle separation means includes a prism.   5. The transmissive optical modulation array according to claim 4, wherein the deflection angle separation means includes an optical path compensation prism that corrects an optical path difference generated according to an arrangement position of each pixel of the transmissive optical deflection array element. apparatus.   The deflection angle separation means has an optical interference film at least in part, introduces outgoing light from the transmissive optical deflection array element into the optical interference film, and converts the introduced light into transmitted light and reflected light. The transmission type light modulation array device according to any one of claims 1 to 3, wherein the transmission type light modulation array device is separated.   The transmissive light modulation array device according to claim 6, wherein the optical interference film includes a dielectric multilayer film.   The transmissive optical modulation array device according to claim 6, wherein the optical interference film includes a cholesteric liquid crystal.   The transmissive optical modulation array device according to claim 6, wherein the optical interference film does not have polarization dependency.   10. The transmissive light modulation array device according to claim 6, wherein the optical interference film separates only the S wave in the light component into transmitted light and reflected light. 11.   The transmissive light modulation array element according to any one of claims 1 to 10, wherein the transmissive light deflection array element is an element that changes a direction of transmitted light by displacing a minute movable film. Array device. A microlens array in which a microlens is formed corresponding to each of the pixels on the light incident side of the light deflection element corresponding to each of the pixels driven by the input signal of the transmissive light deflection array element;
The transmission light modulation array device according to any one of claims 1 to 11, wherein a condensing position by the microlens array is set to a deflection driving position of the light deflection element.   A microlens array in which microlenses are formed corresponding to each of the pixels on the light incident side and the emission side of the light deflection element corresponding to each pixel driven by the input signal of the transmissive light deflection array element, respectively. 13. The transmission type light modulation array device according to claim 12, wherein the transmission type light modulation array device is arranged.   An optical device using the transmission type light modulation array device according to any one of claims 1 to 13.

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