JP2013015613A - Lens module and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens module which is excellent in versatility and mass productivity, and is capable of controlling a lens function electrically.SOLUTION: The lens module includes: a base material (lens material) having a curved-surface shape on a first surface; a functional layer provided on the first surface side of the base material and including a liquid and charged particles; a first conductive film and a second conductive film which are arranged opposed to each other with the functional layer therebetween. When a predetermined electrical charge is selectively applied to at least one of the first and second conductive films, the charged particles move in the liquid (so-called electrophoresis phenomenon occurs), and a state that the charged particles are localized on the base material side or the opposite side of the base material is generated. Thus, the layer state of the liquid and the charged particles in the functional layer is changed, and the lens function (refractive power) of the base material is controlled.

Description

  The present disclosure relates to a lens module and a display device using the lens module.

  In recent years, 3D (3Dimensions) image display methods for realizing stereoscopic vision with the naked eye have been proposed using lenticular lenses (for example, see Patent Documents 1 and 2) and using a parallax barrier. ing. Among these, the lenticular lens method is brighter because it absorbs less light than the parallax barrier method, and has desirable characteristics as a display device. The common point of these 3D display systems is that the resolution when viewed from one direction is lowered in order to output a multi-viewpoint image in multiple directions.

Special table 2009-51942 gazette JP 2010-256432 A

  For this reason, it is desired to display not only a 3D image but also a 2D (2Dimensions) image in a switchable manner. In other words, a function for eliminating the function of the lenticular or barrier is required for 2D display. In this respect, since the parallax barrier can be formed by a liquid crystal panel, switching between 2D display and 3D display can be performed by switching by voltage application. For this reason, it can be easily manufactured and has already been mass-produced.

  On the other hand, the lenticular lens method is expected as a stereoscopic display device due to its bright characteristic, but unlike the above-described parallax barrier, a lenticular lens method is capable of switching between 3D display and 2D display on a large scale. Has not yet reached mass production. In the above Patent Documents 1 and 2, attempts have been made, but there is room for improvement as described below.

  For example, Patent Document 1 discloses a method in which liquid crystal molecules are electrically aligned to give a lens-like phase difference to light. However, with this technique, since the height (thickness) of the lens is regulated by the thickness of the liquid crystal layer, it is difficult to increase the thickness of the lens. For example, in a large-screen display device such as a TV (Television), the size of one pixel is large, so the thickness of the liquid crystal layer is about 170 μm. As described above, when liquid crystal molecules are used for the lenticular lens, it is not only difficult to manufacture, but it takes about several seconds to switch between 2D display and 3D display. For this reason, it is practically difficult to use. In addition, since such a lenticular lens performs a switching operation using polarized light, it is not compatible with a plasma display or an organic EL (Electro luminescence: hereinafter referred to as EL) display that originally emits unpolarized light. It lacks versatility as a module.

  Patent Document 2 proposes a method for controlling the presence or absence of a lens function by using two types of media having different refractive indexes and exchanging the positions of the media. However, in this method, it is necessary to provide a separating ITO for separating each medium. This separating ITO must be set apart from the lenticular lens, and the manufacturing process is not easy and is not suitable for mass production.

  Therefore, it is desired to realize a structure that is excellent in versatility and mass productivity and that can electrically control the lens function in a lens module used for lenticular lens type image display.

  The present disclosure has been made in view of such problems, and an object of the present disclosure is to provide a lens module that is excellent in versatility and mass productivity and can electrically control lens functions, and a display device using the same. There is to do.

  The lens module according to the present disclosure includes a substrate having first and second surfaces facing each other, a curved surface shape on the first surface, a first surface side of the substrate, a liquid, and charged particles. And a first conductive film and a second conductive film disposed to face each other with the functional layer interposed therebetween.

  In the lens module of the present disclosure, a functional layer containing a liquid and charged particles is provided on the first surface side of a substrate having a curved shape, and the first and second conductive films are provided with the functional layer interposed therebetween. It has been. When a predetermined charge is selectively supplied to at least one of the first and second conductive films, the charged particles move in the liquid (so-called electrophoresis phenomenon occurs), and the substrate side or the substrate The charged particles are localized on the opposite side. As a result, the layer state of the liquid and charged particles in the functional layer changes.

  A display device according to the present disclosure includes a display unit and the lens module according to the present disclosure provided on the light emission side of the display unit.

  According to the lens module of the present disclosure, the functional layer containing liquid and charged particles is provided on the first surface (surface having a curved surface) side of the base material, and the first and second layers are provided with the functional layer interposed therebetween. Since the conductive film is provided, the lens function can be switched electrically. In addition, by using the electrophoresis phenomenon, polarization control is unnecessary, and there is no need to install another member for layer separation. Therefore, it is possible to realize a module that is excellent in versatility and mass productivity and can electrically control the lens function. Further, according to the display device of the present disclosure, it is possible to switch between a 3D image and a 2D image, for example, by displaying an image via the lens module of the present disclosure.

It is a schematic diagram showing the structure of the display apparatus using the lens module of one Embodiment of this indication. It is a functional block diagram showing the whole structure of a display apparatus. It is a cross-sectional schematic diagram of the lens module shown in FIG. It is a schematic diagram for demonstrating the image display operation | movement by the display part at the time of 3D mode. 2A and 2B are schematic cross-sectional views for explaining a switching operation of the lens module shown in FIG. 1, in which FIG. 1A shows a 3D display operation, and FIG. 2B shows a 2D display operation. It is a schematic diagram for demonstrating the principle of 3D display. FIG. 9 is a schematic diagram for explaining a lens module according to Modification Example 1. 6 is a schematic cross-sectional view of a lens module according to Modification 2. FIG. It is a cross-sectional schematic diagram for demonstrating switching operation | movement of the lens module shown in FIG. 8, (A) represents at the time of 3D display operation, (B) represents the time at 2D display operation, respectively. It is a cross-sectional schematic diagram for demonstrating switching operation | movement of the lens module which concerns on the modification 3, (A) represents at the time of 3D display operation, (B) represents the time at 2D display operation, respectively. 10 is a schematic cross-sectional view of a lens module according to Modification 4. FIG.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be given in the following order.

1. Embodiment (Example of a display device provided with a lens module that performs lens function control using electrophoretic phenomenon (when the refractive indexes of the liquid and the lens base material are substantially the same))
2. Modification 1 (Example in which the conductive film is divided and a charged particle stirring function is added)
3. Modification 2 (example in which the refractive indexes of the charged particles and the lens base material are substantially the same)
4). Modification 3 (example in which the refractive indexes of charged particles, liquid, and lens substrate are different from each other)
5. Modification Example 4 (Example in which a conductive film is provided on the back surface of a lens substrate)

<Embodiment>
[Configuration of display device]
1 and 2 show a configuration of a display device 1 including a lens module (lens module 1A) according to an embodiment of the present disclosure. The display device 1 is a display capable of displaying a 3D image by a so-called lenticular lens method. In the display device 1, for example, a lens module 1 </ b> A is disposed on the light emission side (image display side) of the display unit 2 with an appropriate interval therebetween. Although details will be described later, the viewer can visually recognize the image formed by the display unit 2 as a 3D image (or 2D image) by viewing the image through the lens module 1A.

  The display unit 2 forms a 3D image visually recognized by an observer or an image corresponding to such a 2D image on a two-dimensional plane, and may be a self-luminous type regardless of the type. In addition, a light source such as a backlight may be required. As such a display part 2, a liquid crystal display, an organic EL display, or a plasma display is mentioned, for example.

  For example, as shown in FIG. 2, the display unit 2 includes a pixel unit 2a in which a plurality of pixels P are provided in a matrix, for example, and a video signal processing unit 30, timing control as a drive circuit for the pixel unit 2a. A unit 31, an image memory 32, an X driver (data driver) 33, and a Y driver (gate driver) 34. The X driver 33 supplies a driving voltage based on the video signal to each pixel P in the pixel unit 2a, and the Y driver 34 performs line sequential operation on each pixel P in the pixel unit 2a along a scanning line (not shown). To drive. The timing control unit 31 controls the X driver 33 and the Y driver 34, and the video signal processing unit 30 processes a video signal from the outside to generate a video signal for 3D display or 2D display. Is. The image memory 32 is a frame memory that stores the video signal generated by the video signal processing unit 30. These drive circuits are formed in, for example, the peripheral region of the pixel unit 2a (the frame region of the panel constituting the display unit 2) in the display unit 2. The display device 1 also includes a lens driving unit 35 that controls the switching operation (on / off switching operation of the lens function) of the lens module 1A based on the control of the video signal processing unit 30, for example.

  The lens module 1A uses an electrophoresis phenomenon as will be described later, so that the response speed is slow and it is difficult to follow the display drive speed of the pixel unit 2a. Therefore, it is not necessary to drive the switching between the 2D image display and the 3D image display and the switching operation in the lens module 1A at strictly synchronized timing (the lens control unit 31 does not need to be controlled by the timing control unit 31). The switching operation in the lens module 1A may be switched in accordance with a switching instruction sent separately from the video signal processing unit 30. However, the lens driving unit 35 may be controlled by the timing control unit 31. The lens driving unit 35 may be disposed in the frame area of the display unit 2 together with the driving circuit, or may be provided in the lens module 1A. Note that these drive circuits (including the lens drive unit 35) may be formed on components separately provided in the peripheral region. In this case, among the drive circuits, for example, the X driver 33 and the Y driver 34 are provided on the front side (display side) of the component, and the image memory 32 and the video signal processing unit 30 are provided on the back side. There are many cases.

  The lens module 1 </ b> A is provided to face at least the pixel portion 2 a of the display portion 2. The lens module 1A includes, for example, a cylindrical lens (semi-cylindrical lens, bowl-shaped lens) having an axis extending in one direction (here, the Y direction) along a direction (X direction) orthogonal to the axial direction. This is a so-called lenticular lens formed by arranging a plurality. Although details will be described later in the present embodiment, the lens function (refractive power) of the lens module 1A can be electrically controlled, and in detail, a switching element that switches on / off of the lens function. It is supposed to function as.

  FIG. 3 schematically shows a cross-sectional structure of the lens module 1A. The lens module 1A includes a transparent conductive film 11 (first conductive film), a functional layer 12, a transparent conductive film 13 (second conductive film), and a counter substrate on the front surface (first surface) side of the lens base material 10. 14.

  The lens substrate 10 has a curved surface shape on its surface. Specifically, the surface shape of the lens substrate 10 has a curved surface shape that can exhibit a lens function in accordance with a difference in refractive index with the material (functional layer 12) formed thereon. Here, a plurality of concave curved surfaces (one concave curved surface corresponds to the cylindrical lens 10a) are arranged along the X direction, whereby the lens module 1A constitutes a lenticular lens as a whole. The surface shape of the lens substrate 10 is determined to be an appropriate shape in consideration of the magnitude relationship among the refractive indexes of the lens substrate 10, the liquid 12a, and the charged particles 12b, the required refractive power, and the like. It may be a curved surface or a convex curved surface. Further, not only the curved surface but also a curved surface having a flat surface in part, that is, a configuration in which polygonal prism (prism) -shaped lenses are arranged instead of the cylindrical lens 10a may be employed. .

  The lens substrate 10 is made of a transparent material (a material that transmits visible light) having a refractive index (n1) of, for example, about 1.35 to 1.75. Examples of such transparent materials include glass materials such as soda lime glass (refractive index 1.51), polymethyl methacrylate (refractive index 1.49), polycarbonate (refractive index 1.585), polyethylene terephthalate (refractive index). For example, a plastic material having a refractive index of about 1.5 to 1.6 is available. On the surface side of the lens base material 10, a counter substrate 14 is disposed with an appropriate distance from the lens base material 10.

  The counter substrate 14 is made of a transparent material. Examples of the transparent material include those similar to the lens substrate 10 described above. Transparent conductive films 11 and 13 are provided on the opposing surfaces of the lens base 10 and the counter substrate 14.

  Examples of the transparent conductive films 11 and 13 include a conductive film having transparency to visible light, specifically, ITO (indium tin oxide), IZO (indium zinc oxide), FTO (fluorine-doped tin oxide), and the like. . Among these, the transparent conductive film 11 is formed in a surface shape that follows the surface shape of the lens substrate 10 (a curved surface shape corresponding to the cylindrical lens 10a). On the other hand, the surface of the transparent conductive film 13 on the functional layer 12 side is a flat surface. Although the thickness of these transparent conductive films 11 and 13 is not specifically limited, For example, it is about 10 nm-500 nm. The transparent conductive films 11 and 13 may be coated with, for example, a fluorine-based surface modifier for the purpose of extending the electrode life. A functional layer 12 is enclosed between the transparent conductive films 11 and 13 so that a potential difference is applied to the functional layer 12 through the transparent conductive films 11 and 13 (any one of the transparent conductive films 11 and 13). Positive or negative charge can be supplied).

  The functional layer 12 includes, for example, charged particles 12b in the liquid 12a, and has a thickness equal to or greater than the lens thickness t1 of the lens substrate 10. The liquid 12a is a dispersion medium for the charged particles 12b and is made of an organic solvent having an insulating property. The charged particle 12b is a particle having a property of being charged to a positive or negative polarity in the liquid 12a, and is made of, for example, a metal material, a metal oxide, or a resin material. Various coatings may be applied to the charged particles 12b in order to improve chargeability and dispersibility. Both of the liquid 12a and the charged particles 12b are desirably transparent to visible light. In the present embodiment, either one of them has a refractive index substantially the same as that of the lens substrate 10. Have. In addition, “refractive index” in this specification indicates “absolute refractive index” inherent to the material.

  Although the content of the charged particles 12b in the liquid 12a is not particularly limited, it is desirable that the following conditions are satisfied. That is, in a state where the charged particles 12b are localized on the lens base material 10 side, the thickness is equal to or greater than the thickness t1 (depth) of the concave portion in the curved shape of the lens base material 10 (the charged particles 12b are filled in the concave curved surface. It is good to contain the amount. Although details will be described later, this is because the lens function of the lens substrate 10 is effectively exhibited when the charged particles 12b are moved to the lens substrate 10 side.

In the present embodiment, the refractive index (na) of the liquid 12a substantially matches the refractive index n1 of the lens substrate 10, and the refractive index (nb) of the charged particles is different from the refractive index n1 of the lens substrate 10. (Here, nb> n1). For example, when the lens substrate 10 is made of a material having a refractive index of around 1.5 as described above, the liquid 12a is tetrachloroethylene (refractive index 1.504), and the charged particles 12b is titanium dioxide (TiO 2). _{2 with} a refractive index of 2.72). Titanium dioxide has the property of being negatively charged in the tetrachloroethylene by the surface hydroxyl group releasing hydrogen ions. Further, in this specification, the “refractive index of each material” is not limited to the case where the respective refractive index values are completely matched (same), and for example, 0.1% between them. The concept includes a case where there is a difference in refractive index of less than about. Further, “different” in the refractive index of each material means that the lens base material has a refractive index difference enough to obtain a desired refractive power.

  Such a functional layer 12 is preferably made of a colloidal solution, and the charged particles 12b may have a very small particle size. In the functional layer 12, the charged particles 12b settle or float according to the specific gravity difference between the liquid 12a and the charged particles 12b. Here, for example, the specific gravity of tetrachloroethylene is 1.62 and the specific gravity of titanium dioxide is 4.5. Therefore, if the particle diameter of titanium dioxide is large, the titanium dioxide particles settle, for example, along the Y direction. Particularly, in a large electronic device such as a TV, since the cylindrical lens 10a is installed so that the extending direction (Y direction) is vertical, titanium dioxide accumulates at the bottom of the screen if left for a long time. For this reason, when the specific gravity of the charged particles 12b is larger than the specific gravity of the liquid 12a, it is desirable to make the particle size of the charged particles 12b minute as described above. As a result, the Brownian motion becomes active (becomes less susceptible to gravity), and the sedimentation speed can be reduced. In the case of titanium dioxide, the particle diameter is preferably 100 nm or less, for example. Conversely, even when the specific gravity of the charged particle 12b is smaller than the specific gravity of the liquid 12a, the charged particle size may be designed so that the Brownian motion is superior to gravity, as in the above case.

  The lens module 1A as described above can be manufactured, for example, as follows. That is, first, the lens base material 10 is formed by forming the above-described surface shape on the base material made of the above-described material using, for example, a roll-out manufacturing method or a melt extrusion method. Thereafter, the transparent conductive film 11 made of the above-described material is formed on the surface of the lens substrate 10 by, for example, sputtering. On the other hand, the transparent conductive film 13 is similarly formed on one surface of the counter substrate 14. Next, for example, a liquid 12a made of the above-described material mixed with the charged particles 12b is applied onto the transparent conductive film 11, and then the transparent conductive film 13 side of the counter substrate 14 is formed thereon using a spacer, for example. The peripheral part is sealed while being kept at a distance of. Thereby, the lens base material 10 and the counter substrate 14 are bonded. In this way, the lens module 1A can be manufactured.

[Action / Effect]
In the present embodiment, when each pixel P is driven on the display unit 2 based on a video signal input from the outside, an image based on the video signal is displayed on a two-dimensional plane (for example, the lens module 1A side of the display unit 2). It is projected on the surface. At this time, when a 3D image is displayed (3D mode), a driving voltage corresponding to a 3D video signal is supplied to each pixel P under the control of the timing control unit 31. On the other hand, when a 2D image is displayed (2D mode), a driving voltage corresponding to a 2D video signal is supplied to each pixel P under the control of the timing control unit 31. Note that switching between the 3D mode and the 2D mode is performed based on, for example, a selection signal supplied from the outside together with the video signal. In this way, the display unit 2 forms a 3D image or an image corresponding to the 2D image on a two-dimensional plane.

  In the 3D mode, the image generated by the display unit 2 is an image in which multi-viewpoint images are arranged in a spatially and periodically manner. For example, as shown in FIG. 4A, a viewpoint image corresponding to each viewpoint in the multi-viewpoint direction is displayed on a plurality of adjacent pixels (here, ten red pixels R1 to R10) along the X direction. Is done. As shown in FIG. 4B, these viewpoint images R1 to R10 are images (or pseudo-photographed) respectively taken from 10 viewpoints D1 to D10 with respect to one point (imaging target point) A. Image). Such ten pixels are defined as one unit (U1), and this unit U1 is arranged with a predetermined period for each color. On the other hand, when a 2D image is displayed (2D mode), the image is displayed for each pixel P.

  5A and 5B schematically show an example of the operation (switching operation) of the lens module 1A in each of the 3D mode and the 2D mode. In the present embodiment, as described above, the refractive index n1 of the lens substrate 10 and the refractive index na of the liquid 12a are substantially equal, and the refractive index nb of the charged particles 12b is different from the refractive index n1, but in this case, the transparent conductive By supplying a charge having a polarity opposite to the polarity of the charged particle 12b to any one of the films 11 and 13, the lens function of the lens module 1A is controlled as described below.

(3D mode)
In the 3D mode, the lens driving unit 35 supplies charges having a polarity opposite to the polarity of the charged particles 12b to the transparent conductive film 11 on the lens substrate 10 side, for example, under the control of the video signal processing unit 30. Specifically, a positive potential is applied to the transparent conductive film 11 as shown in FIG. Thereby, for example, negatively charged charged particles 12b move to the transparent conductive film 11 side (lens substrate 10 side) (electrophoresis occurs). The voltage to be applied may be a direct current or an alternating current. In the case of alternating current, the moving speed of the charged particles 12b can be improved. As a result, the functional layer 12 is in a layer state in which the charged particles 12b are localized only on the lens substrate 10 side in the liquid 12a.

  For example, when tetrachloroethylene is used as the liquid 12a and titanium dioxide is used as the charged particles 12b, the charged particles 12b (titanium dioxide particles) are changed by setting the distance between the transparent conductive films 11 and 13 to 100 μm and the applied voltage to 15V, for example. , Can be moved to the position as shown.

  At this time, since there is a predetermined refractive index difference (n1 <nb) between the lens substrate 10 and the charged particles 12b, a lens (lenticular lens) corresponding to the refractive index difference and the curved surface shape of the lens substrate 10 is used. The function of the lens or the cylindrical lens 10a) is exhibited (expresses the function of such a lens). That is, the light L incident from the lens substrate 10 side is refracted in the vicinity of the interface between the lens substrate 10 (specifically, the transparent conductive film 11) and the functional layer 12. The charged particles 12b desirably have a thickness equal to or greater than the thickness t1 in the curved shape of the lens substrate 10 in a state where the charged particles 12b are localized on the lens substrate 10 side. Thereby, the charged particles 12b are filled so as to flatten the concave curved surface of the lens substrate 10, the lens function of the lens substrate 10 is effectively exhibited, and the interface between the charged particles 12b and the liquid 12a is flat. Thus, light loss due to the interface between the charged particles 12b and the liquid 12a can be reduced.

  Accordingly, in the 3D mode, for example, as illustrated in FIG. 6, viewpoint images R1 to R10 (viewpoint images R1 to R10 illustrated in FIG. 4A) displayed on the two-dimensional plane (surface S) of the display unit 2. Are refracted in different directions by the lens module 1A and emitted. As a result, images R1 'to R10' corresponding to ten viewpoints that generate parallax (binocular parallax) are displayed to the observer who views the surface S of the display unit 2 through the lens module 1A. That is, the observer can obtain a stereoscopic effect corresponding to the parallax between these images by perceiving different images of these images R1 ′ to R10 ′ with each of the left eye and the right eye. it can.

(2D mode)
In the 2D mode, the lens driving unit 35 supplies charges having a polarity opposite to the polarity of the charged particles 12b to the transparent conductive film 13 on the counter substrate 14 side, for example, under the control of the video signal processing unit 30. Specifically, as shown in FIG. 5B, by applying a positive potential to the transparent conductive film 13, for example, negatively charged charged particles 12b on the transparent conductive film 13 side (opposing substrate 14 side). Moves (electrophoresis occurs). Thereby, in the functional layer 12, the charged particles 12b are localized only on the counter substrate 14 side in the liquid 12a, and the lens base material 10 side is in a layer state filled with the liquid 12a.

  At this time, since the refractive indexes of the lens base material 10 and the liquid 12a are substantially the same, the lens function of the lens base material 10 is not exhibited (the lens function is not expressed). That is, for example, the light L incident from the lens base material 10 side passes through the lens base material 10 and the functional layer 12 without being refracted in the vicinity of the interface between the lens base material 10 and the functional layer 12, and is on the counter substrate 14. Is emitted.

  Accordingly, in the 2D mode, the lens module 1A does not hinder the image display on the display unit 2. For this reason, the observer can visually recognize the image displayed on the two-dimensional plane of the display unit 2 as a normal 2D image.

  As described above, in the lens module 1A, by providing the functional layer 12 including the liquid 12a having a predetermined refractive index and the charged particles 12b between the transparent conductive films 11 and 13, the electrophoretic phenomenon is utilized. The lens function can be controlled. Specifically, in the present embodiment, the lens function is achieved by substantially matching the refractive indexes of the lens substrate 10 and the liquid 12a and supplying the transparent conductive film 11 with a charge having a polarity opposite to that of the charged particles 12b. (Passing light is refracted) and 3D image display can be realized. On the other hand, by supplying a charge having the opposite polarity to the charged particles 12b to the transparent conductive film 13, the lens function is lost (light is allowed to pass through without being refracted), and 2D image display can be realized.

  As described above, in the present embodiment, the lens module 1A is provided with the functional layer 12 including the liquid 12a and the charged particles 12b on the surface side (curved surface side) of the lens base material 10, and the functional layer 12 is interposed between Since the transparent conductive films 11 and 13 are provided, the lens function can be electrically controlled. That is, by utilizing the electrophoresis phenomenon of the charged particles 12b, the lens module 1A can function as a switching element that switches on / off of the lens function. Here, since the polarization control is required when the above switching is performed using the alignment of the liquid crystal, the combination with a display (such as an organic EL display) that does not originally use polarized light is poor. On the other hand, since the polarization control is not required by using the electrophoresis phenomenon as in the present embodiment, it can be suitably combined with such a display as a module. Furthermore, in the functional layer 12, for example, it is not necessary to separately install a member for separating the liquid 12a and the charged particles 12b, so that the manufacturing process is not complicated. Therefore, it is possible to realize a module that is excellent in versatility and mass productivity and can electrically control the lens function of light. Further, the display device 1 can switch between a 3D image and a 2D image, for example, by displaying an image using such a lens module 1A.

  In the above embodiment, the case where the refractive index of the charged particle 12b is larger than the refractive index of the lens base material 10 is exemplified, but the refractive index of the charged particle 12b is smaller than the refractive index of the lens base material 10. Each material may be selected. Even in such a case, an effect equivalent to that of the above-described embodiment can be obtained by setting the curved surface shape of the lens substrate 10 to an appropriate shape.

  Next, modified examples (modified examples 1 to 4) of the lens module of the above embodiment will be described. In the following, the same components as those in the above embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

<Modification 1>
FIG. 7 is a schematic diagram for explaining a lens module according to the first modification. In the above embodiment, it has been described that in the lens module 1A, the transparent conductive films 11 and 13 are provided with the functional layer 12 interposed therebetween. However, one or both of these transparent conductive films 11 and 13 include a plurality of transparent conductive films 11 and 13. It may be divided into electrodes (sub-electrodes). In this example, the transparent conductive film 13 on the counter substrate 14 side is divided into a plurality of sub-electrodes 13a. Each of the plurality of sub-electrodes 13a preferably has a strip shape having long sides along the X direction. In this example, the transparent conductive film 11 on the lens base material 10 side has a shape that follows the surface shape of the lens base material 10 as in the above embodiment.

  In this modification, for example, the lens driving unit 35 shown in FIG. 2 applies a positive or negative potential to each of the plurality of sub-electrodes 13a in a space-divided manner at a predetermined timing. At this time, for example, the scanning is performed in the positive or negative direction in the Y direction (from the upper part to the lower part and from the lower part to the upper part), for example, while reversing the potential. As described above, particularly when the lens module is installed with the Y direction as the vertical direction, the charged particles easily settle below the lens module due to the influence of gravity. As in this modification, the charged conductive particles 13 can be stirred by dividing the transparent conductive film 13 and sequentially supplying a positive or negative potential to each of them. Thereby, even if the charged particles settle due to gravity, the charged particles can be dispersed again in the liquid. However, since the switching operation of the lens module accompanying the image display operation as described in the above embodiment is hindered during the stirring operation, the stirring operation by applying the voltage is performed during a period when the image display is not performed ( For example, it is desirable that the operation is performed for several seconds after the electronic device is switched off (after the image display operation is completed).

  Note that the method of applying a potential is not limited to the method of scanning while reversing positive and negative as described above, and other application methods may be used as long as charged particles can be stirred. In this example, the transparent conductive film 13 on the counter substrate 14 side is divided into a plurality of parts. However, the transparent conductive film 11 on the lens base material 10 side may be divided, or both of them may be divided. Further, the shape and number of sub-electrodes (number of divisions) are not limited to those illustrated.

  As described above, at least one of the transparent conductive films 11 and 13 may be divided into a plurality of pieces and the charged particles may be stirred. Also in this case, when displaying a 2D image, if a charge having a polarity opposite to that of the charged particles is supplied to all of the plurality of sub-electrodes 13a, the same 2D image display as in the above embodiment can be performed. it can. Therefore, an effect equivalent to that of the above embodiment can be obtained. In addition, when sedimentation of charged particles occurs, the lens function changes between the upper part and the lower part of the lens module, which may cause a difference in appearance at the top and bottom of the screen, which may reduce display quality. However, the charged particles can be dispersed again by performing the stirring operation as described above. Therefore, a highly accurate switching operation using the electrophoresis phenomenon can be realized.

<Modification 2>
FIG. 8 illustrates a cross-sectional configuration of a lens module 1B according to Modification 2. In the above embodiment, the case where the refractive indexes of the lens base material 10 and the liquid 12a are substantially the same and the refractive indexes of the lens base material 10 and the charged particles 12b are different is illustrated. It is not limited. For example, as in the present modification, the refractive indexes of the lens substrate (lens substrate 20) and the charged particles (charged particles 22b) are substantially the same, and the refractive indexes of the lens substrate 20 and the liquid 22a are different. Also good.

(Constitution)
Similarly to the lens module 1A of the above-described embodiment, the lens module 1B is used in combination with the display unit 2 as a module, for example, in the display device as described above. The lens module 1B is provided so as to face at least the pixel portion 2a. For example, a plurality of cylindrical lenses (semi-cylindrical lenses, bowl-shaped lenses) 20a having an axis in the Y direction are arranged in the X direction. It functions as a lenticular lens. The lens module 1B also includes a transparent conductive film 21 (first conductive film), a functional layer 22, a transparent conductive film 13, and a counter substrate 14 on the front surface (first surface) side of the lens base material 20. Is.

  However, in the present modification, the curved surface shape of the lens substrate 20 is such that a plurality of convex curved surfaces (one convex curved surface corresponds to the cylindrical lens 20a) is arranged along the X direction. A transparent conductive film 21 is formed on the surface of the lens base 20 facing the counter substrate 14 with a surface shape that follows the surface shape of the lens base 20. As the lens base material 20, for example, a transparent material having a refractive index (n1) in the same range as the above embodiment is used. The transparent conductive film 21 is made of the same material and thickness as the transparent conductive films 11 and 13 of the above embodiment. Further, a predetermined potential difference is given to the functional layer 22 through the transparent conductive films 21 and 13 (a positive or negative charge can be supplied to either of the transparent conductive films 21 and 13. )

  The functional layer 22 includes charged particles 22b in a liquid 22a as a dispersion medium, as in the functional layer 12 of the above embodiment, and the liquid 22a is made of an organic solvent having an insulating property. The charged particles 22b are particles having a property of being charged to a positive or negative polarity in the liquid 22a, and are made of, for example, a metal material or a metal oxide. Various coatings may be applied to the charged particles 22b in order to improve chargeability and dispersibility. Further, for the same reason as the functional layer 12 of the above embodiment, the functional layer 22 is preferably a colloidal solution when the specific gravity of the charged particles 22b is larger than the specific gravity of the liquid 22a, and the charged particles 22b It is preferable that the particle size of the is small.

  Although the content of the charged particles 22b in the liquid 22a is not particularly limited, it is desirable that the following conditions are satisfied. That is, in the state where the charged particles 22b are localized on the lens base material 20 side, the thickness is equal to or greater than the thickness t2 of the convex portion of the curved shape of the lens base material 20 (the concave portion between the adjacent convex curved surfaces of the charged particles 22b. 20b). This is because when the charged particles 22b are moved to the lens base material 20 side, the lens function of the lens base material 20 is uniformly lost.

  In the present modification, as described above, the refractive index nb of the charged particle 22b substantially matches the refractive index n1 of the lens substrate 20, and the refractive index na of the liquid 22a is different from the refractive index n1 of the lens substrate 20. . (Here na <n1). For example, when the lens substrate 20 is made of a material having a refractive index of about 1.5 as described above, the liquid 22a is, for example, silicone oil (refractive index 1.4), and the charged particles 22b is a refractive index. A resin material of around 1.5 is used. Examples of such charged particles 22b include acrylic resins. Here, the case where the charged particles 22b are negatively charged in the liquid 22a will be described as an example.

(Action / Effect)
FIGS. 9A and 9B schematically show an example of the operation (switching operation) of the lens module 1B in each mode of the 3D mode and the 2D mode. In the lens module 1B of the present modification example, as described above, the refractive index n1 of the lens substrate 20 and the refractive index nb of the charged particles 22b substantially match, and the refractive index na of the liquid 22a differs from the refractive index n1, In this case as well, the lens function can be controlled by supplying a charge having a polarity opposite to the polarity of the charged particles 22b to one of the transparent conductive films 21 and 13, as in the above embodiment. However, in the present modification, as described below, the relative positional relationship between the liquid 22a and the charged particles 22b in each mode of the 3D mode and the 2D mode is different from that in the above embodiment.

  Specifically, in the 3D mode, as shown in FIG. 9A, for example, a charge having a polarity opposite to the polarity of the charged particles 22b is supplied to the transparent conductive film 13 on the counter substrate 14 side (here, A positive potential is applied to the transparent conductive film 13). Thereby, for example, negatively charged charged particles 22b move to the transparent conductive film 13 side (counter substrate 14 side) (electrophoresis phenomenon occurs). As a result, the charged particles 22b are localized only on the counter substrate 14 side in the liquid 22a, and the lens base material 20 side is in a layered state filled with the liquid 22a.

  At this time, in this modification, there is a predetermined refractive index difference (n1> na) between the lens base 20 and the liquid 22a. The function of the lens (lenticular lens or cylindrical lens 20a) is exhibited. That is, the light L incident from the lens substrate 20 side is refracted in the vicinity of the interface between the lens substrate 20 (specifically, the transparent conductive film 21) and the functional layer 22. Accordingly, in the 3D mode, as in the above embodiment, each light corresponding to each of the multi-viewpoint images formed two-dimensionally by the display unit 2 is refracted and emitted in different directions by the lens module 1B. .

  On the other hand, in the 2D mode, as shown in FIG. 9B, for example, a charge having a polarity opposite to the polarity of the charged particles 22b is supplied to the transparent conductive film 21 on the lens substrate 20 side (here, transparent conductive film). A positive potential is applied to the membrane 21). Thereby, for example, negatively charged charged particles 22b move to the transparent conductive film 21 side (lens base material 20 side) (electrophoresis occurs). As a result, the functional layer 22 is in a layer state in which the charged particles 22b are localized only on the lens substrate 10 side in the liquid 22a.

  At this time, in this modified example, since the refractive indexes of the lens substrate 20 and the charged particles 22b are substantially the same, the lens function of the lens substrate 20 is not exhibited. That is, for example, the light L incident from the lens base material 20 side passes through the lens base material 20 and the functional layer 22 without being refracted in the vicinity of the interface between the lens base material 20 and the functional layer 22, and is on the counter substrate 14. Is emitted. Accordingly, in the 2D mode, the lens module 1 </ b> B does not hinder the image display by the display unit 2 as in the above embodiment.

  As described above, also in the present modified example, in the lens module 1B, in the lens module 1B, the functional layer 22 including the liquid 22a having a predetermined refractive index and the charged particles 22b between the transparent conductive films 21 and 13. By providing the lens function, it is possible to control the lens function using the electrophoresis phenomenon. Specifically, in this modification, the lens function is achieved by substantially matching the refractive indexes of the lens substrate 20 and the charged particles 22b and supplying the transparent conductive film 13 with a charge having the opposite polarity to the charged particles 22b. (Passing light is refracted) and 3D image display can be realized. On the other hand, by supplying a charge having the opposite polarity to the charged particles 22b to the transparent conductive film 21, the lens function is lost (light is allowed to pass through without being refracted), and 2D image display can be realized. Therefore, in this modification, an effect equivalent to that of the above embodiment can be obtained.

  In the second modification, the case where the refractive index of the liquid 22a is smaller than the refractive index of the lens base material 20 is exemplified, but each of the liquid 22a has a refractive index larger than the refractive index of the lens base material 20. Material may be selected. Even in such a case, an effect equivalent to that of the above-described embodiment can be obtained by setting the curved surface shape of the lens substrate 20 to an appropriate shape.

<Modification 3>
In the above embodiment and the second modification, the case where the refractive index of either one of the liquid and the charged particles substantially matches the refractive index of the lens base material is exemplified. The refractive indexes of the liquid 23a and the charged particles 23b are different from each other. In addition, what is necessary is just to select an appropriate thing as a lens base material 20, the liquid 23a, and the charged particle 23b so that a mutual refractive index may differ from the materials mentioned above. In addition, here, a configuration using the lens base material 20 having the convex curved surface described in the first modification is illustrated.

  FIGS. 10A and 10B schematically show an example of the operation (switching operation) in the 3D mode and the 2D mode of the lens module (lens module 1C) of this modification. Also in this modification, the lens function can be controlled by providing the functional layer 23 including the liquid 23a and the charged particles 23b between the transparent conductive films 21 and 13 as in the above embodiment. However, in this modified example, as described below, the operation in the 2D mode is different from the above-described embodiment and the like.

  Specifically, in the 3D mode, as shown in FIG. 10A, as in the above-described modification 2, for example, the transparent conductive film 13 on the counter substrate 14 side has a charge with a polarity opposite to that of the charged particles 23b. (Here, a positive potential is applied to the transparent conductive film 13). Thereby, for example, negatively charged charged particles 23b move to the transparent conductive film 13 side (counter substrate 14 side) (electrophoresis occurs). As a result, the charged particles 23b are localized only on the counter substrate 14 side in the liquid 23a, and the lens base material 20 side is in a layered state filled with the liquid 23a.

  At this time, in this modified example, there is a predetermined refractive index difference between the lens base material 20 and the liquid 23a. Therefore, a lens (lenticular lens or lens) corresponding to the refractive index difference and the curved shape of the lens base material 20 is used. The function of the cylindrical lens 20a) is exhibited. That is, the light L incident from the lens substrate 20 side is refracted in the vicinity of the interface between the lens substrate 20 (specifically, the transparent conductive film 21) and the functional layer 22. Therefore, in the 3D mode, as in the above-described embodiment, each light corresponding to each of the multi-viewpoint images formed two-dimensionally by the display unit 2 is refracted and emitted in different directions.

  On the other hand, in the 2D mode, as shown in FIG. 10B, the charged particles 23b are dispersed in the liquid 23a. That is, in this modification, the lens function of the lens base material 20 is lost due to the scattering action of the charged particles 23b by leaving no potential difference between the transparent conductive films 21 and 13. Therefore, in the 2D mode, the image display by the display unit 2 is not greatly affected. However, since the sharpness of the image may be lost due to the scattering action, it is desirable to reduce the content of the charged particles 23b as much as possible.

  As described above, also in the present modification, in the lens module 1C, the functional layer including the liquid 23a having the predetermined refractive index and the charged particles 23b is provided between the transparent conductive films 21 and 13 in substantially the same manner as in the above embodiment. By providing 23, the lens function can be controlled using the electrophoresis phenomenon. Specifically, in the present modification, the refractive indexes of the lens base material 20, the liquid 23a, and the charged particles 23b are made different from each other, and a charge having a polarity opposite to that of the charged particles 22b is supplied to the transparent conductive film 13. The 3D image display can be realized by exhibiting the lens function (refracting the passing light). On the other hand, the lens function is lost (light is allowed to pass through without being refracted) by using the scattering action of the charged particles 23b dispersed in the liquid 23a without applying a potential difference to the transparent conductive films 21 and 13, and a 2D image. Display can be realized. Therefore, also in the present modification, it is possible to obtain substantially the same effect as the above embodiment.

  Moreover, in this modification, it is not necessary to collect the charged particles 23b on the curved surface side of the uneven lens base 20 in both the 3D mode and the 2D mode. Here, when a potential is applied to the transparent conductive film 21, the unevenness of the electric field strength may occur on the lens base material 20 side due to the uneven shape. As a result, the charged particles 23b collect in a biased area on the lens base material 20 side (not in a desired area). Accordingly, by controlling the lens function without collecting the charged particles 23b on the lens base material 20 side as in this modification, it is possible to prevent such bias of the charged particles 23b.

<Modification 4>
FIG. 11 illustrates a cross-sectional configuration of a lens module (lens module 1D) according to Modification 4. In the above embodiment and Modifications 1 to 3, one of the pair of transparent conductive films sandwiching the functional layer is provided on the surface of the lens substrate (first surface having a curved surface shape). As described above, the transparent conductive film 24 may be provided on the back surface (flat second surface) of the lens substrate 10. Even in such a case, an effect equivalent to that of the above-described embodiment and the like can be obtained. In the present modification, the distance between the functional layer 12 and the transparent conductive film 24 is increased by the thickness of the lens substrate 10, so that the voltage applied to the functional layer 12 is set larger than in the above-described embodiment. Although it is necessary, since the transparent conductive film 24 can be formed on the flat surface of the lens substrate 10, uneven film thickness hardly occurs and the film forming process becomes easy. In addition, there is an effect of preventing a short circuit with the transparent conductive film 13 on the counter substrate 14 side.

  As described above, the embodiments and modifications have been described, but the present disclosure is not limited to the aspects described in the embodiments and the like, and various modifications can be made. For example, in the above-described embodiment and the like, the charged particles of the present disclosure have been described by way of example of those that are negatively charged in a liquid. However, charged particles may be positively charged depending on the material used. Good. However, in this case, when realizing the 3D mode or the 2D mode, a negative charge is supplied to one of the transparent conductive films.

  Moreover, in the said embodiment etc., although the case where light was entered from the back surface side of a lens base material (when a display part is installed in the back surface side of a lens base material) was illustrated, this indication is not limited to this. Alternatively, light may be incident from the counter substrate 14 side. Further, the surface on the functional layer side of the counter substrate 14 (transparent conductive film 13) is a flat surface, but each cylindrical lens may have a curved surface.

  Furthermore, in the above-described embodiments and the like, a display device that can switch between 3D display and 2D display in which a lens module is combined with a display unit has been described. However, the lens module according to the present disclosure is other than such a video display device. It can also be applied to electronic devices. For example, the present invention can be applied to an imaging device (camera) that can shoot by switching between 3D video and 2D video. Further, since the lens module functions as a switching element that switches on / off of the lens function, it can be used for various purposes other than the above-described 3D / 2D switching. For example, as described above, the lens module can switch three functions of transmitting (transmitting without being refracted), collecting (refracting and transmitting), or scattering the light passing therethrough. The present invention can also be applied to lighting that uses simple switching.

In addition, the lens module of this indication may have a structure as described in the following (1)-(12).
(1) A substrate having first and second surfaces facing each other, having a curved surface shape on the first surface, provided on the first surface side of the substrate, and liquid and charged particles. A lens module comprising: a functional layer including: a first conductive film and a second conductive film disposed to face each other with the functional layer interposed therebetween.
(2) The lens module according to (1), wherein a refractive index of any one of the liquid and the charged particles of the functional layer substantially matches a refractive index of the base material.
(3) The first conductive film is provided on the first or second surface of the base material, and the second conductive film is provided on the side of the functional layer opposite to the base material. The lens module according to (1) or (2) above.
(4) The refractive index of the liquid and the refractive index of the base material substantially coincide with each other, the refractive index of the charged particle and the refractive index of the base material are different from each other, and the charged particle is formed on the first conductive film. The lens function in the base material is exhibited by supplying a charge having a polarity different from that of the charged particles, and the charge function having a polarity different from that of the charged particles is supplied to the second conductive film. The lens module according to any one of (1) to (3), wherein:
(5) The refractive index of the charged particle and the refractive index of the base material substantially coincide with each other, the refractive index of the liquid and the refractive index of the base material are different from each other, and the charged particle is formed on the second conductive film. The lens function in the base material is exhibited by supplying a charge having a polarity different from that of the charged particle to the first conductive film. The lens module according to any one of (1) to (4), wherein:
(6) The lens module according to any one of (1) to (5), wherein the base material, the liquid, and the charged particles have different refractive indexes.
(7) The first conductive film is provided on the first or second surface of the base material, and the second conductive film is provided on a surface of the functional layer opposite to the base material. The second conductive film is supplied with a charge having a polarity different from that of the charged particles, thereby exhibiting a lens function in the base material, and the charged particles are dispersed in the functional layer, thereby the base material. The lens module according to (6), wherein the lens function is not exhibited.
(8) The lens module according to any one of (1) to (7), wherein at least one of the first and second conductive films is divided into a plurality of sub-electrodes.
(9) The lens module according to (8), wherein a positive or negative potential is applied to each of the plurality of sub-electrodes.
(10) The above-mentioned (1) to (9), wherein the curved surface shape of the base material has a lens function as a lenticular lens, in which a plurality of semicylindrical surfaces having an axis extending in one direction are arranged. The lens module according to any one of the above.
(11) The lens module according to any one of (1) to (10), wherein the functional layer has a thickness larger than a thickness of a convex portion or a concave portion in the curved surface shape.
(12) The lens module according to any one of (1) to (11), wherein the first conductive film has a surface shape that follows the curved shape of the base material.

In addition, the display device of the present disclosure may have a configuration as described in the following (13) to (15), and further includes the lens module described in the above (2) to (12). You may do it.
(13) A display unit and a lens module provided on the light emission side of the display unit, the lens module having first and second surfaces facing each other, and the first surface having a curved surface shape A functional layer containing liquid and charged particles, and a first conductive film and a second conductive film disposed opposite to each other with the functional layer in between A display device.
(14) A lens driving unit that drives the lens module is provided, and the lens driving unit supplies a charge different from the polarity of the charged particles to one of the first and second conductive films. The display device according to (13), in which a three-dimensional image display is performed, and a charge different from the polarity of the charged particles is supplied to the other conductive film to perform a two-dimensional image display.
(15) A lens driving unit that drives the lens module is provided, and the lens driving unit supplies a charge different from the polarity of the charged particles to one of the first and second conductive films. The display device according to (13) or (14), in which a three-dimensional image display is performed, and a two-dimensional image display is performed in a state where no voltage is applied to the functional layer.

  DESCRIPTION OF SYMBOLS 1 ... Display apparatus, 1A-1D ... Lens module, 2 ... Display part, 10, 20 ... Lens base material, 11, 21, 13 ... Transparent conductive film, 12, 22, 23 ... Functional layer, 12a, 22a, 23a ... Liquid, 12b, 22b, 23b ... charged particles, 14 ... counter substrate.

Claims (15)

A substrate having first and second surfaces facing each other and having a curved surface shape on the first surface;
A functional layer provided on the first surface side of the base material and containing a liquid and charged particles;
A lens module comprising: first and second conductive films disposed to face each other with the functional layer interposed therebetween. The lens module according to claim 1, wherein a refractive index of any one of the liquid and the charged particles in the functional layer substantially matches a refractive index of the base material. The first conductive film is provided on the first or second surface of the base material,
The lens module according to claim 2, wherein the second conductive film is provided on the side of the functional layer opposite to the base material. The refractive index of the liquid and the refractive index of the base material substantially coincide with each other, and the refractive index of the charged particles and the refractive index of the base material are different from each other,
By supplying a charge having a polarity different from that of the charged particles to the first conductive film, the lens function in the substrate is exhibited,
The lens module according to claim 3, wherein the lens function of the base material is not exhibited by supplying a charge having a polarity different from that of the charged particles to the second conductive film. The refractive index of the charged particles and the refractive index of the base material substantially match, and the refractive index of the liquid and the refractive index of the base material are different from each other,
By supplying a charge having a polarity different from that of the charged particles to the second conductive film, the lens function in the substrate is exhibited,
The lens module according to claim 3, wherein the lens function of the base material is not exhibited by supplying charges having a polarity different from that of the charged particles to the first conductive film. The lens module according to claim 1, wherein the base material, the liquid, and the charged particles have different refractive indexes. The first conductive film is provided on the first or second surface of the base material,
The second conductive film is provided on the surface of the functional layer opposite to the base material,
By supplying a charge having a polarity different from that of the charged particles to the second conductive film, the lens function in the substrate is exhibited,
The lens module according to claim 6, wherein the charged particles are dispersed in the functional layer, so that the lens function of the base material is not exhibited. The lens module according to claim 1, wherein at least one of the first and second conductive films is divided into a plurality of sub-electrodes. The lens module according to claim 8, wherein a positive or negative potential is applied to each of the plurality of sub-electrodes. The curved surface shape of the base material is a plurality of semi-cylindrical surfaces having an axis extending in one direction,
The lens module according to claim 1, having a lens function as a lenticular lens. The lens module according to claim 1, wherein the functional layer has a thickness larger than a thickness of a convex portion or a concave portion in the curved surface shape. The lens module according to claim 1, wherein the first conductive film has a surface shape that follows the curved shape of the base material. A display unit, and a lens module provided on the light emission side of the display unit,
The lens module is
A substrate having first and second surfaces facing each other and having a curved surface shape on the first surface;
A functional layer provided on the first surface side of the base material and containing a liquid and charged particles;
And a first conductive film and a second conductive film disposed to face each other with the functional layer interposed therebetween. A lens driving unit for driving the lens module;
The lens driving unit is
Three-dimensional image display is performed by supplying a charge different from the polarity of the charged particles to one of the first and second conductive films,
The display device according to claim 13, wherein a two-dimensional image display is performed by supplying a charge different from a polarity of the charged particles to the other conductive film. A lens driving unit for driving the lens module;
The lens driving unit is
Three-dimensional image display is performed by supplying a charge different from the polarity of the charged particles to one of the first and second conductive films,
The display device according to claim 13, wherein two-dimensional image display is performed in a state where no voltage is applied to the functional layer.

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