JP2003315693A - Image display element and projector device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display element which can be made thin with an inexpensive and simple structure and a projector device which uses the same and to thereby reduce the total cost and overall size of the projector device. <P>SOLUTION: The image display element 100 is provided with a transparent substrate 21, an optical modulation part 15 which is provided on one surface of the transparent substrate 21 and optically modules incident light through electromechanical operation, and a Fresnel lens 19 which is provided on the other surface of the transparent substrate 21 and refracts light transmitted through the transparent substrate 21. Then the projector device is equipped with the image display element 100, a light source which introduces the light into the image display element 100, and a signal processing part which converts image data into a driving signal for the optical modulation part 15, and the projector device performs ON/OFF control over the optical modulation part 15 according to the image data to enlarge and project a formed image through the Fresnel lens 19. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display element for optically modulating introduced light by electromechanical operation to form an image, and a projector device using the same.

[0002]

2. Description of the Related Art There is a projector device for displaying a magnified image by projecting a still image or a moving image on a screen. In this type of projector device, an image that is a source of a projected image is displayed using a liquid crystal display element (LCD),
In some cases, the light from the light source is transmitted, and the image formed on the LCD is enlarged and formed on the screen for projection.

In an LCD, an oriented liquid crystal is put between a pair of transparent substrates having a conductive transparent film and sealed, and this is sandwiched between polarizing plates whose polarization directions are orthogonal to each other, and a voltage is applied to the conductive transparent film. By applying, the liquid crystal molecules are aligned vertically to the substrate, and the transmittance of light from the light source is changed to display an image. However, the LCD transmits the light from the light source between the polarizing plate and the aligned liquid crystal molecules, so that the light utilization efficiency is lowered and a complicated manufacturing process such as injection and alignment of the liquid crystal is required. However, there are drawbacks that the applied voltage is high and it is difficult to drive at high speed.

Therefore, a projector device is provided which is capable of high-speed modulation as compared with an LCD, is excellent in displaying a digital image with high image quality, and has an optical modulator for optically modulating the introduced light from the light source by electromechanical operation. Proposed. In this projector device, as shown in FIG. 13, a light modulator 3 is provided on one surface of a transparent substrate 1 such as a glass substrate, and the other surface of the transparent substrate 1 is separated from the transparent substrate 1 by a lens 5. Are arranged opposite to each other, light emitted from a light source (not shown) on the right side of the drawing is refracted by the lens 5, and the refracted light is transmitted to the light modulating portion 3, whereby an image 7a formed on the light modulating portion 3 is illustrated. The image is enlarged and formed as a projected image 7b on the screen.

[0005]

However, in the above projector device provided with the light modulator for performing the light modulation by the electromechanical operation, the lenses are arranged opposite to each other on the other surface of the transparent substrate. A holding structure for securely fixing the lens to the transparent substrate and a space therefor are required, and at the same time, the lens has to be positioned with high precision, so that the lens assembling workability is poor and the manufacturing cost is high. was there. Further, since the separate lens is arranged apart from the transparent substrate, the distance between the transparent substrate and the lens becomes optically long, and it becomes difficult to reduce the thickness of the main part of the projector device. There was a problem that the entire device could not be downsized.

The present invention has been made in view of the above circumstances, and provides an image display element which is inexpensive and can be thinned by a simple structure, and a projector device using the same.
Therefore, it is an object to reduce the cost and downsize the entire projector device.

[0007]

An image display device according to a first aspect of the present invention for achieving the above object is a transparent substrate and an electromechanical device provided with light introduced on one surface of the transparent substrate. It is characterized by comprising a light modulator for performing light modulation by an operation, and a Fresnel lens provided on the other surface of the transparent substrate and refracting light transmitted through the transparent substrate.

In this image display device, by providing a Fresnel lens on the other surface of the transparent substrate, the optical system is assembled using one surface of the transparent substrate on the side that does not affect the light modulation operation, and a separate body is formed. As compared with the conventional structure in which the lenses are provided facing each other, the workability of assembling the lens is improved and the distance to the lens is shortened. As a result, the image display element can be simplified and can be made inexpensive and thin (small).

An image display device according to a second aspect of the invention is characterized in that the Fresnel lens is formed integrally with the transparent substrate.

In this image display device, the transparent substrate and the Fresnel lens can be constructed by one member. To form the Fresnel lens integrally with the transparent substrate, the transparent substrate may be etched or integrally molded. As a result, the transparent substrate and the Fresnel lens become the same medium, and there is no boundary surface between them, so that there is no reflection at the boundary surface and a high transmittance can be obtained.

An image display device according to a third aspect of the present invention is characterized in that a Fresnel lens formed separately from the transparent substrate is attached to the other surface of the transparent substrate.

In this image display device, the Fresnel lens is formed separately from the transparent substrate, so that the material suitable for each member can be selected. Further, it becomes possible to adopt an optimum manufacturing method for each member, which makes it possible to improve productivity and reduce manufacturing costs. Further, it becomes possible to select and attach a desired one from pre-manufactured Fresnel lenses of different specifications, and it is possible to flexibly deal with the manufacture of a wide variety of image display elements.

According to another aspect of the image display device of the present invention, a transparent substrate, a light modulator provided on one surface of the transparent substrate for optically modulating introduced light by electromechanical operation, and the other surface of the transparent substrate. A first transparent flat plate fixed to the first transparent flat plate, a second transparent flat plate arranged in parallel to the surface of the first transparent flat plate with the transparent substrate interposed therebetween, and side faces of the first and second transparent flat plates. A surrounding wall member is provided to form an accommodation space for accommodating the light modulator, and a Fresnel lens is provided on an outer surface of either the first or second transparent flat plate.

In this image display device, it is housed in a housing space in which the light modulator is sealed and can be shielded from the external atmosphere.
It is possible to prevent dust and the like from adhering to the movable thin film or the like of the light modulation portion, and to improve the reliability of the light modulation operation. Also, compared to the conventional structure in which the optical system is assembled by using the transparent flat plate of the sealing body and the separate lens is provided facing, the workability of assembling the lens is improved and the distance from the lens is improved. Becomes shorter. As a result, the image display element can be simplified and can be made inexpensive and thin (small).

An image display device according to a fifth aspect of the invention is characterized in that the Fresnel lens is formed integrally with either the first or second transparent flat plate.

In this image display device, the transparent flat plate and the Fresnel lens can be constructed by one member. To form the Fresnel lens integrally with the transparent substrate, the transparent substrate may be etched or integrally molded. As a result, the transparent substrate and the Fresnel lens become the same medium, and there is no boundary surface between them, so that there is no reflection at the boundary surface and a high transmittance can be obtained.

An image display device according to a sixth aspect of the invention is characterized in that a Fresnel lens formed separately from the transparent flat plate is attached to the first or second transparent flat plate.

In this image display element, by forming the Fresnel lens and the transparent flat plate separately, it is possible to select the material suitable for each member. Further, it becomes possible to adopt an optimum manufacturing method for each member, which makes it possible to improve productivity and reduce manufacturing costs. Further, it becomes possible to select and attach a desired one from pre-manufactured Fresnel lenses of different specifications, and it is possible to flexibly deal with the manufacture of a wide variety of image display elements.

An image display device according to a seventh aspect is characterized in that a distance between the Fresnel lens and the light modulation section is shorter than a focal length of the Fresnel lens.

With this image display device, the image magnified by the Fresnel lens can be observed as an erecting virtual image.

In the image display device according to the present invention, the light modulating section faces the movable section supported by the movable section so as to move toward and away from the substrate, and the movable section and the substrate, respectively. A pair of electrodes provided, and the electrostatic force generated by applying a drive voltage between the electrodes causes the movable portion to perform an attracting operation with respect to the substrate, thereby reducing the transmittance with respect to the introduced light by an optical interference effect. It is characterized by changing by.

In this image display element, the movable portion is attracted to the substrate by the electrostatic force, and the transmittance for the introduced light changes. By performing optical modulation by such an optical interference effect, it becomes possible to reduce the size of the image display element, reduce the voltage, and speed up the display operation.

A projector device according to a ninth aspect is a projector device using the image display element according to any one of the first to eighth aspects, wherein a light source for introducing light into the image display element, A signal processing unit for converting display image data into a drive signal for the light modulation unit, and an image formed by on / off controlling the light modulation unit according to the image data is formed by the Fresnel lens. It is characterized in that the image is enlarged and projected.

In this projector device, the image formed on the light modulator is enlarged and projected by the Fresnel lens provided on the transparent substrate or the transparent plate. Since the light modulator has a simple structure, the distance between the image display element and the lens is short. As a result, the main part of the projector device becomes thin, and the entire projector device can be downsized.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of an image display device and a projector device using the same according to the present invention will be described in detail below with reference to the drawings. 1 is a cross-sectional view of an image display device according to the present invention, FIG. 2 is a diagram showing a schematic configuration of a projector device equipped with the image display device of FIG. 1, and FIG. 3 is a partially enlarged view of the image display device and its light modulating portion. 4A and 4B are cross-sectional views illustrating an example of an individual element configuration of the light modulator and its operation.

The image display device 100 of this embodiment is shown in FIG.
As shown in FIG. 2, the transparent substrate 21, the light modulator 15 provided on one surface of the transparent substrate 21 for optically modulating the introduced light by electromechanical operation, and provided on the other surface of the transparent substrate 21 to transmit the light. And a Fresnel lens 19 for refracting light. The transparent substrate 21 should just be transparent with respect to the introduced light, for example, a glass substrate, a plastic substrate, etc. can be used.

FIG. 2 shows an example of the configuration in which the image display device 100 is applied to a projector device. The projector device 150 includes an image display element 100, a light source 11 that introduces light into the image display element 100, and the image display element 100.
A signal processing unit 17 for converting image data into a drive signal and transmitting the same to the light modulation unit 15 and an input image signal processing unit 18 for converting input image signals of various forms into RGB image data forms. The light modulator 15 is provided according to the image data.
The image 7a formed by ON / OFF control is enlarged by the Fresnel lens 19 and enlarged and projected as a projected image 7b on a screen (not shown). The Fresnel lens 19 may be disposed on either the light incident side or the light emitting side of the light modulator 15, and in the present embodiment,
The Fresnel lens 19 is arranged on the light incident side of the transparent substrate 21.

As shown in FIG. 3, the light modulator 15 is composed of two-dimensionally arranged light modulators 16 and each of the light modulators 16 is individually on / off controlled by a signal processor 17. It is controlled by so-called simple matrix drive. In each of the light modulation elements 16, as shown in FIG. 4, for example, a movable thin film (movable portion) 23 having flexibility is supported on a transparent substrate 21 via a pillar 24 so as to approach the transparent substrate 21. It is movable in the separating direction. Both the movable thin film 23 and the transparent substrate 21 are arranged in such a manner that the transparent electrodes 25, 26 and the dielectric multilayer film 27,
28 and 28 are provided in this order. That is, a pair of transparent electrodes 2 is provided between the movable thin film 23 and the transparent substrate 21.
5, 26 and a pair of dielectric multilayer films 27, 28 provided inside thereof.

The transparent electrode 26 is transparent to the modulated light.
It may be made of ITO or the like. Dielectric multilayer film
27 and 28 are, for example, SiO₂/ TiO₂Is it a multilayer stack of
Consists of Then, a drive voltage is applied between the transparent electrodes 25 and 26.
When applied, an electrostatic force is generated between the transparent electrodes 25 and 26.
Then, from the state in which the movable thin film 23 is shown in FIG.
As shown in (b), the transparent substrate 21 is sucked and moved.
It By such an electromechanical operation, the movable thin film 23 and the transparent thin film are transparent.
The thickness of the gap 29 between the bright substrate 21 and_OffTo t_{o n}To
By changing it, the optical characteristics of the light modulation element for the introduced light can be changed.
The on / off control of light is performed by changing the sex. In other words, yes
By bending the moving thin film 23, multilayer film interference (fab
The optical modulation is performed by generating the Repeller interference. In addition, this
For details of the light modulator 16, for example, Japanese Patent Laid-Open No. 11-
As described in Japanese Patent No. 258558,
Please refer.

An image 7a based on image data is displayed by electromechanically operating each of the light modulation elements 16 described above with one pixel and driving voltage output from the signal processing section 17 to each light modulation element 16.

In the image display device 100, the Fresnel lens 19 is provided on the other surface of the transparent substrate 21 as described above, but the Fresnel lens 19 and the transparent substrate 21 may be integrally formed. In that case, Fresnel lens 1
9 can be formed by etching or integrally molding the other surface of the transparent substrate 21. As a result, the element structure can be simplified, and the boundary surface between the transparent substrate 21 and the Fresnel lens 19 does not exist, so that there is no reflection on the boundary surface and a high light transmittance can be obtained. Further, the Fresnel lens 19 may be formed separately from the transparent substrate 21 and attached to the other surface of the transparent substrate 21.
In this case, a material suitable for each member can be selected, and the degree of freedom in design can be increased. In addition, it becomes possible to select and attach a desired one from a plurality of Fresnel lenses 19 having different focal lengths prepared in advance, so that the image display device 100 can be applied to a wide range and can be versatile. You can As the Fresnel lens 19, a distance between the Fresnel lens 19 and the light modulator 15 is shorter than the focal length of the Fresnel lens 19. Thereby, the image magnified by the Fresnel lens 19 can be observed as an erecting virtual image.

Next, the signal processing for driving the image display element 100 will be described. FIG. 5 is a block diagram showing the configuration of the signal processing unit 17. Input image signal processing unit 1
The image signal to be input to 8 is usually an RGB signal in bitmap format, a composite video signal (Y / C signal) obtained by combining a luminance signal Y and a color signal C, or JPE.
There are compressed data signals such as G. The RGB signal can be used as it is as the image data 30, but the compressed data signal is expanded by the expansion processing unit 32 and converted into a Y / C signal, and Y
The / C signal is converted into an RGB signal by the YC / RGB conversion unit 34. These conversion processes can be performed by software or hardware.

The signal processor 17 mainly has a data format converter 31, a simple matrix drive timing generator 33, and a signal level converter 35. The data format conversion unit 31 converts the input image data 30 into an on / off signal for each light modulation element according to the gradation pattern. At this time, for good gradation expression, optimization may be performed by referring to a look-up table LUT prepared in advance and appropriately converting the gradation. In the simple matrix drive timing generator 33,
An on / off signal to each light modulation element arranged in a matrix is generated as a simple matrix drive signal, and the signal level conversion unit 35 converts the generated simple matrix drive signal into a predetermined drive signal in voltage level. Light modulator 15
Send to. As a result, the image 7a based on the image data 30 is displayed on the image display element 100.

Here, a specific control method for driving the image display device 100 in a simple matrix will be described with reference to FIGS. FIG. 6 is an explanatory diagram showing a hysteresis characteristic of light transmittance with respect to an applied voltage, FIG. 7 is a diagram showing a part of a light modulator in which light modulators are two-dimensionally arranged, and FIG. 8 is a summary of input signals to the light modulator. FIG. 9 is an explanatory diagram showing an image data writing signal to the light modulation element. When deforming and elastically restoring the movable thin film by electrostatic force,
The relationship between the voltage applied to the electrodes 25 and 26 and the displacement of the movable thin film 23 shows a hysteresis characteristic. Therefore, the applied voltage Vgs
And the light transmittance T also show a hysteresis characteristic as shown in FIG.

According to this hysteresis characteristic, the optical modulator 16 has OF when the applied voltage Vgs is Vth (L) or less.
The F (light shielding) state is maintained. On the other hand, the applied voltage Vgs is V
Above s (H), the light modulation element 16 is ON (light transmission)
Saturate to the state. After that, the light modulation element 16 remains in the ON state when the applied voltage Vgs is Vth (H) or higher. Then, when the applied voltage Vgs becomes Vs (L) or less, the light modulation element 16 is saturated in the OFF state. That is, if the applied voltage Vgs is in the range between Vth (H) and Vth (L), the light modulation element 16 may generate T (O) depending on the history of the applied voltage Vgs.
Two states, N) and T (OFF), can be obtained.
When the polarity of the applied voltage Vgs is negative, the characteristics are symmetrical with the above and the vertical axis.

As shown in FIG. 7, the optical modulator 16 having the above characteristics is shown in FIG. 7. For simplification of the description, the intersections Tr (1,1), Tr (1,2) and Tr (1,2) of the 2 × 2 matrix are shown. 2, 1) and Tr (2, 2), respectively. Each light modulation element 16 corresponds to one pixel area.

The electrodes 26 on the movable thin film 23 side of the light modulation elements 16 arranged in the same row are commonly connected to each other to serve as scanning electrodes. A potential Vg is applied to this scan electrode. Further, the electrodes 25 on the transparent substrate 21 side of the light modulation elements 16 arranged in the same column are commonly connected to each other to serve as signal electrodes. A potential Vb is applied to this signal electrode. Therefore, the electrodes 25 applied to each light modulation element 16,
The voltage Vgs between 26 becomes (Vb-Vg). In order to drive the matrix-shaped light modulation element 16, the scan electrodes are scanned row by row in accordance with the scan signals, and in synchronization with this, a data signal corresponding to the scanned scan electrodes is applied to the signal electrodes.

Here, as shown in FIG. 8, three kinds of signals (voltages) of a reset signal, a selection signal, and a non-selection signal are applied to the scan electrodes. The reset signal is applied to the light modulation element 16 of the row regardless of the previous state of the light modulation element 16.
Is turned off (light shield). The voltage of the scan electrode at this time is Vg (r).

The selection signal is a signal for writing data in the row. Simultaneously with this signal, the state of the light modulation element 16 is determined to be ON (light transmission) or OFF (light shielding) according to the voltage applied to the signal electrode. The voltage of the scan electrode at this time is Vg (s). The non-selection signal is a signal when no selection is made. At this time, the state of the light modulation element 16 does not change regardless of the voltage of the signal electrode, and the previous state is maintained. The voltage of the scan electrode at this time is Vg (ns).

On the other hand, two kinds of signals (voltage), an ON signal and an OFF signal, are applied to the signal electrode. ON signal is
With respect to the light modulation elements 16 in the selected row, the light modulation elements 16
Is turned on (light transmission). The voltage of the signal electrode at this time is Vb (on). The OFF signal turns off the state of the light modulation element 16 with respect to the light modulation element 16 of the selected row.
Set to (light shield). However, in reality, since it is assumed that the light modulation element 16 is reset immediately before, when the state of the light modulation element 16 is turned off (light blocking), the previous state (OFF state) is maintained. The signal to do is all right. The voltage of the signal electrode at this time is Vb (off).

The inter-electrode voltage Vgs of the light modulation element 16 can be divided into the following six types of voltages by the combination of the scan electrode voltage and the signal electrode voltage described above. Also, the voltage between electrodes Vgs
And the characteristics of transmittance give specific conditions. Vgs (r-on) = Vb (on) -Vg (r) ≤ Vs (L) Vgs (r-off) = Vb (off) -Vg (r) ≤ Vs (L) Vgs (s-on) = Vb (on) −Vg (s) ≧ Vs (H) Vgs (s-off) = Vb (off) −Vg (s) ≦ Vth (L) Vgs (ns-on) = Vb (on) −Vg (ns) ≤ Vth (L) Vgs (ns-off) = Vb (off) -Vg (ns) ≥ Vth (H)

The above conditions are shown in FIG.
For example, when the scan electrode voltage Vg is reset Vg (r) and the signal electrode voltage Vb is ON, that is, Vb (on), the signal electrode voltage Vb (thick solid line 41 in the figure) having a value larger than Vs (H) ,
The scan electrode voltage Vg (thick solid line 43 in the figure) having a value between Vs (H) and Vth (L) is subtracted, and the value (thick solid line 45 in the figure) becomes smaller than Vs (L). That is, Vgs (r-on) ≦ Vs (L). In the same manner as above, six kinds of voltages are determined.

Next, a method of writing data in a matrix in which the light modulation elements 16 are two-dimensionally arranged by utilizing the relationship between the inter-electrode voltage Vgs and the transmittance will be described. It is considered that data is written using the matrix of 2 rows and 2 columns shown in FIG. 7 as the matrix. The following ON / OFF data is written in each light modulation element 16 of the matrix. Tr (1,1) → ON Tr (1,2) → OFF Tr (2,1) → OFF Tr (2,2) → ON

A voltage having a waveform as shown in FIG. 9 is applied to the matrix. For example, t1: reset voltage t2: selection voltage t3: non-selection voltage t4: non-selection voltage is applied to the first row Vg (1). T1: don't care t2: ON voltage t3: OFF voltage t4: don't care are applied to the first column Vb (1). As a result, desired data is written in each light modulation element 16 row by row.

That is, for example, in the case of the matrix Tr (1,1) in the first row and first column described above, since Vgs: Vb (1) -Vg (1), t1: reset voltage (OFF) t2: ON t3 = state maintenance t4 = state maintenance.

Therefore, the ON state at t2 is maintained (memory), and as a result, the matrix Tr (1,1) is in the "ON" state of the light modulation element 16. Similarly, other matrix Tr (1,2) is “OFF”, Tr (2,1)
Is "OFF" and Tr (2,2) is "ON". As described above, a desired image can be displayed by turning on the scanning electrodes row by row and applying an arbitrary potential from the signal electrodes in synchronization with the ON.

The projector device 15 of this embodiment is used.
0 indicates that the video signal (analog signal) output from the video camera 37 is converted into an A / D converter 3 as shown in FIG.
9 may be converted into a digital image and converted into image data 30, and the image data 30 may be processed by the signal processing unit 17 as described above and displayed on the image display element 100. Further, although the above-mentioned example describes the display control by the simple matrix drive, the display control may be performed by the active drive system in which an active element such as a transistor is provided for each pixel. In that case, it is possible to display an image by analog control of displacement without providing the light modulation element with a hysteresis characteristic.

Thus, the image display device 1 of this embodiment
00, the light modulator 15 is formed on one surface of the transparent substrate 21.
Since the Fresnel lens 19 is provided on the other surface,
The one surface of the transparent substrate 21 that is not involved in the light modulation operation can be effectively used. Therefore, as compared with the conventional structure in which the lens is provided separately from the transparent substrate 21 so as to face it, a holding structure for fixing the lens to the transparent substrate and a space therefor are unnecessary, and the lens is positioned with high accuracy. Since it is not necessary, the lens assembling work becomes simple, and the manufacturing cost can be reduced to a simple structure. By configuring the projector device 150 using the image display element 100, the main part of the projector device that performs the projection operation can be made thinner, and as a result, the entire projector device can be made smaller and thinner.

Next, a second embodiment of the image display device according to the present invention will be described. 11 is a sectional view showing a second embodiment of the image display device according to the present invention, and FIG. 12 is a sectional view showing a modification of the image display device shown in FIG. The image display device 200 according to the present embodiment includes a transparent substrate 21, a light modulator 15 provided on one surface of the transparent substrate 21, and a transparent flat plate such as glass (first plate) fixed to the other surface of the transparent substrate 21.
Transparent transparent plate) 45, a transparent flat plate (second transparent flat plate) 47 made of glass or the like arranged in parallel to the surface of the transparent flat plate 45 with the transparent substrate 21 interposed therebetween, and the side faces of the transparent flat plates 45, 47 are surrounded. An accommodation space 4 that includes a peripheral wall member 48 and that accommodates the light modulator 15 by the transparent flat plates 45 and 47 and the peripheral wall member 48.
3 is formed. The Fresnel lens 19 is provided on the outer surface of the transparent flat plate 47 to which the transparent substrate 21 is fixed.

This Fresnel lens 19 can also be formed integrally with the transparent flat plate 47 by etching or integrally molding the outer surface of the transparent flat plate 47 into a Fresnel lens shape, as in the case of the image display device 100 described above. In that case, the element structure can be simplified and a high light transmittance can be obtained. Further, the Fresnel lens 19 may be formed separately from the transparent flat plate 47 and attached to the outer surface of the transparent flat plate 47, and a lens having desired specifications can be selectively used to increase the degree of freedom in design. Can be improved.

As shown in FIG. 12, the image display element 200 may be an image display element 300 having a structure in which the Fresnel lens 19 is arranged on the transparent flat plate 47 on the light emitting side of the light modulating section 15 side. .

Image display devices 200, 3 according to the present embodiment
According to 00, in addition to the effect of the configuration of the first embodiment described above, since the light modulator 15 is housed in the housing space 43 of the sealing body 49 in a sealed manner, it can be shielded from the external atmosphere, and the light modulation can be performed. It is possible to prevent foreign matter such as dust from adhering to the movable thin film 23 and the like of the portion 15. Further, by enclosing a rare gas or the like in the accommodation space 43, it is possible to prevent the element member from being deteriorated due to a chemical change or the like. As a result, the reliability of the light modulation operation is enhanced, and stable operation can be obtained for a long period of time.

The optical modulator in each of the above-described embodiments uses an optical modulator that performs optical modulation by the electromechanical operation of the interference film, but the present invention is not limited to this, and, for example, Japanese Patent Laid-Open Publication No. Hei 11 As described in JP-A-258558,
An element structure in which a light-shielding film having flexibility is bent by application of an electric field to create a light-shielding state and a light-transmitting state, or a light-shielding light modulation element in which the light-shielding film itself slides and modulates light by application of an electric field Good. Alternatively, a movable thin film may be provided in the total reflection light guide plate so that the movable thin film can be brought close to the total reflection light guide plate, and the total reflection condition is changed by the optical coupling action of the moving thin film approaching / separating operation to perform optical modulation.

Further, the image display element according to the present invention can be appropriately applied to other display applications besides being applied to the projector device.

[0055]

As described in detail above, according to the image display device of the present invention, the transparent substrate is provided on one surface with an optical modulator for optically modulating the introduced light by electromechanical operation. Since a Fresnel lens that refracts light that passes through the transparent substrate is provided on the other surface of the substrate, the optical system can be assembled using one surface of the transparent substrate that does not affect the light modulation operation. As compared with the conventional structure in which the body lenses are provided facing each other, the workability of assembling the lenses can be improved and the distance to the lenses can be shortened. As a result, the image display element can be simplified and can be made inexpensive and thin.

According to the projector device of the present invention,
The image display device, a light source for introducing light into the image display device, and a signal processing unit for converting image data into a drive signal for the light modulation unit are provided, and the light modulation unit is turned on / off according to the image data. Since the image formed by control is magnified and projected by the Fresnel lens, the light modulator has an inexpensive and simple structure, and since the image display element is thin, a projector device that performs a projection operation can be used. The main part can be thinned, and as a result, the entire projector device can be downsized.

[Brief description of drawings]

FIG. 1 is a sectional view of an image display device according to the present invention.

FIG. 2 is a diagram showing a schematic configuration of a projector device equipped with the image display element of FIG.

FIG. 3 is a partially enlarged view of an image display element and a light modulation section thereof.

FIG. 4 is a cross-sectional view illustrating an example of an individual element configuration of an optical modulator and its operation.

FIG. 5 is a block diagram showing a configuration of a signal processing unit.

FIG. 6 is an explanatory diagram showing a hysteresis characteristic of light transmittance with respect to an applied voltage of the light modulation element.

FIG. 7 is a diagram showing a part of a light modulator in which light modulators are two-dimensionally arranged.

FIG. 8 is an explanatory diagram collectively showing input signals to the light modulation element.

FIG. 9 is an explanatory diagram showing a signal for writing image data to the light modulation element.

FIG. 10 is a block diagram showing obtaining image data from a video camera.

FIG. 11 is a sectional view showing a second embodiment of the image display element according to the present invention.

12 is a cross-sectional view showing a modified example of the image display element shown in FIG.

FIG. 13 is a main part configuration diagram showing a conventional projector device.

[Explanation of symbols]

11 light source 13 Image display device 15 Light modulator 16 Light modulator 17 Signal processing unit 19 Fresnel lens 21 Transparent substrate 23 Movable thin film (movable part) 24 props 25,26 transparent electrode 27,28 Dielectric multilayer film 29 void 30 image data 31 Data format converter 33 Simple matrix drive timing generator 35 signal level converter 43 accommodation space 45,47 transparent plate 48 peripheral wall members 49 sealed body 100,200,300 Image display device 150 projector device

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H041 AA05 AB00 AB38 AC06 AZ05                       AZ08                 2K103 AA05 AA16 AB07 BB03 BC24                       BC47 CA18 CA29                 5C058 AB06 AB07 BA01 EA02 EA12                       EA27 EA51

Claims (9)

[Claims] 1. A transparent substrate, an optical modulator provided on one surface of the transparent substrate for optically modulating introduced light by electromechanical operation, and provided on the other surface of the transparent substrate to transmit the transparent substrate. And a Fresnel lens for refracting the light that is generated. 2. The image display device according to claim 1, wherein the Fresnel lens is formed integrally with the transparent substrate. 3. The image display device according to claim 1, wherein a Fresnel lens formed separately from the transparent substrate is attached to the other surface of the transparent substrate. 4. A transparent substrate, a light modulator provided on one surface of the transparent substrate for optically modulating introduced light by electromechanical operation, and a first transparent flat plate fixed to the other surface of the transparent substrate. A second transparent flat plate arranged in parallel with the surface of the first transparent flat plate with the transparent substrate sandwiched therebetween; and a peripheral wall member surrounding side surfaces of the first and second transparent flat plates. An image display element, characterized in that a housing space for housing the light modulator is formed and a Fresnel lens is provided on an outer surface of either the first or second transparent flat plate. 5. The image display element according to claim 4, wherein the Fresnel lens is formed integrally with either the first transparent plate or the second transparent flat plate. 6. The image display device according to claim 4, wherein a Fresnel lens formed separately from the transparent flat plate is attached to the first or second transparent flat plate. 7. The image display device according to claim 1, wherein a distance between the Fresnel lens and the light modulator is shorter than a focal length of the Fresnel lens. 8. The light modulation section includes a movable section movably supported in a direction toward and away from the substrate, and a pair of electrodes provided so as to face each of the movable section and the substrate. Then, the movable part is attracted to the substrate by an electrostatic force generated by applying a drive voltage between the electrodes, and the transmittance with respect to the introduced light is changed by an optical interference effect. The image display element according to any one of claims 1 to 7. 9. A projector device using the image display element according to claim 1, wherein a light source for introducing light into the image display element, and image data for display are provided. A signal processing unit for converting into a drive signal for the light modulation unit, and an image formed by on / off controlling the light modulation unit according to the image data is enlarged and projected by the Fresnel lens. A projector device characterized by the above.