JP2008076623A - Liquid crystal lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal lens which can be easily manufactured and has a uniform heater construction nearly free from gap unevenness in a cell. <P>SOLUTION: The liquid crystal lens interposing a liquid crystal layer and functioning as a variable focal lens, is characterized in that a seal has such a constitution that a first frame-shaped seal is provided at an outer edge of a transparent substrate and a second seal in which a spacer considering film thickness difference due to film thickness of a heater or the like is mixed is disposed on the heater on the inner side of the first seal and on the outer side of a lens region for phase modulation of the liquid crystal layer while the heater for efficiently heating is made to exist on the peripheral part of an effective lens region as a measure against low temperature. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal lens having a heater structure, and more particularly to a liquid crystal lens that is uniform and resistant to external stress even though it has a simple structure and eliminates gap unevenness in a cell.

  Conventionally, as a focusing mechanism for changing the focal length or focal position of an optical system, a method of focusing by moving a lens has been widely used. However, this method requires a lens driving mechanism, and thus has a drawback that the mechanism is complicated and a lens driving motor requires a relatively large amount of electric power. In addition, there is a drawback that the impact resistance is generally low. Thus, as a focusing mechanism that does not require a lens driving mechanism, a method of focusing by changing the refractive index of a liquid crystal lens is known. This method using a liquid crystal lens functions as a variable focus lens by changing the refractive index distribution of the liquid crystal lens by changing the voltage (drive voltage) applied to the liquid crystal lens to drive the liquid crystal lens. It is.

  However, in this conventional liquid crystal lens, the viscosity of the liquid crystal increases as the temperature is lowered, so that the response of the liquid crystal to the voltage is delayed, and there is a problem that it takes a long time until focusing. .

  In view of this, a configuration has been proposed in which a heater is included inside the cell, together with a transparent electrode pattern for causing the liquid crystal lens to function as a variable focus lens (see Patent Document 1).

  By the way, when a liquid crystal lens is used as a variable focus lens, the surface accuracy is important in expressing the characteristics as a lens, as in other optical components such as a plastic lens and a glass lens. The surface accuracy in the case of the liquid crystal lens here corresponds to a characteristic value in both flatness, which is a relative value in the effective lens region surface, and uniformity as an absolute value of the in-plane cell gap distribution.

  This liquid crystal lens is formed by stacking two glass substrates, and a transparent electrode is patterned on the glass substrate as an electrode for driving the liquid crystal to obtain a desired retardation distribution. One of the transparent electrodes has a ring-shaped electrode, and the other has a solid common electrode. Moreover, after mixing a spacer in the thermosetting epoxy sealing material which adhere | attaches glass substrates, or UV curable acrylic sealing material, two glass substrates are pressure-baked, and glass is obtained. The cell gap between the substrates is regulated. This cell gap is regulated mainly by mixing spacers made of glass fiber and silica beads into the seal and spraying spacers made of plastic beads and silica beads inside the cell (inside the seal that injects liquid crystal). There are two ways.

  Since these glass fibers and silica beads are relatively hard materials, the spacer becomes a support column when the seal is cured by pressure firing between two glass substrates, and the cell gap is regulated by the particle size of the spacer. . On the other hand, plastic beads are a relatively soft material, and are used mainly for the purpose of maintaining a cell gap by acting as a repulsive force when liquid crystal contracts due to temperature or external stress.

As described above, in order to uniformly regulate the cell gap, it is sufficient to distribute the spacers uniformly at the target locations and use many spacers. However, if there are spacers in the effective lens region, The spacer portion causes the incident light to be transmitted and diffused, and in some cases, diffracted light is generated. Further, since this spacer disturbs the alignment of the liquid crystal around the spacer, aberration is generated in the light incident on the liquid crystal lens, and the characteristics as the variable focus lens are deteriorated. That is, if a spacer exists in the effective lens region, a desired refractive index distribution cannot be obtained, and the lens function is hindered.

  In particular, in the case where the cell gap is increased in order to increase the retardation value, the particle size of the spacer increases despite the fact that the effective lens diameter does not change. growing. For this reason, the problem of the above-mentioned transmission diffusion, the problem of diffraction, and the problem of occurrence of aberration due to disorder of alignment become more remarkable.

  In addition, in order to create a cell gap by mixing glass fibers in the seal, increasing the ratio of mixing spacers in the seal will reduce the ground contact area between the seal and the glass substrate, thereby increasing the adhesion of the seal. Strength will be impaired. If the seal is made thicker, it will hinder downsizing. For example, if the cell gap is to be made uniform only with the glass fiber in the seal, when the seal is arranged away from the effective lens region, the cell gap changes as the distance from the vicinity of the seal increases. The surface accuracy is worse.

Therefore, by using a seal in the spacer and the cell in the spacer, as a method for the absence of spacers in yet effective lens area locally performed N ₂ blowing a dispenser after spacer spraying, the skip spacers effective lens area 1 And a second manufacturing method using a metal mask at the time of dispersing the spacers to prevent the spacers from being scattered in the effective lens region (for example, see Patent Document 2).

Japanese Patent Laying-Open No. 2006-201243 (pages 13-14, FIGS. 1, 4-5) Japanese Unexamined Patent Publication No. 2000-81600 (page 4-6, FIGS. 1 and 5-6)

  In Patent Document 1, as a heater, a transparent electrode substrate made of indium tin oxide or the like and a light-shielding metal made of a metal material mainly composed of chromium in order to make an electric current flow easily through the heater electrode are common to an annular pattern. A heater is formed around the electrodes. Since the heater cannot be formed in the effective lens region if the heater is a light-shielding material, it is highly desirable to dispose it in the periphery. However, the liquid crystal lens described in Patent Document 1 does not take into account the above-described surface accuracy associated with these members, and when a metal film is formed on a transparent electrode, it is natural that there is a step between the place where the metal film is located and the place where the metal film is located. Will occur. Therefore, depending on the balance with the spacer for determining the gap and the seal in which the spacer is mixed, the surface accuracy of the cell gap may be affected.

  For example, as an example, if there are 500 mm of alignment films arranged with a liquid crystal layer sandwiched therebetween (1000 mm because there are two layers at the top and bottom), and the thickness of the heater is 4000 mm, there will be a step of 5000 mm on the transparent substrate. It is happening. Therefore, a gap difference of 5000 mm is generated depending on the place where the seal on the transparent substrate is arranged. As a result, the surface accuracy of the cell gap may be deteriorated.

Further, in the first manufacturing method in Patent Document 2, if the spacer in the cell is blown away by performing N ₂ blow and the spacer in the effective lens region can be surely eliminated, the problem of transmission diffusion, the problem of diffraction, It is possible to eliminate the problem of the occurrence of aberration due to the alignment disturbance.

However, in this method, it is impossible to control where the spacers fly, and the flying destination may again enter the effective lens area of the same cell or an adjacent cell, and this phenomenon is not reproducible. . As described above, since the position where the spacer is blown is not reproducible, it is necessary to check whether the spacer exists in the effective lens region after performing N ₂ blow once. If present, the N ₂ blow must be performed again.

In addition, although this method is performed in order to blow off the spacer only in the effective lens area, there is a possibility that the spacer outside the effective lens area may be blown off. That is, since the spacer near the effective lens region is likely to be blown away by N ₂ blow, it is difficult to accurately regulate the surface accuracy of the effective lens region. In this way, it is apparent that this method is difficult to spread the spacers in the vicinity of the effective lens region.

  In the second manufacturing method, the effective lens region is selectively masked using a metal mask, and the spacers are scattered outside the effective lens region, and the effective lens region and the metal mask are first arranged. It is difficult to obtain position accuracy.

  In addition, the spacer may enter between the metal mask and the glass substrate, and the spacer may exist in the effective lens region. When the mask area is larger than the mask opening, most of the spacers remain on the mask, and the effective usage rate of the spacers is low and wasteful.

  Further, in order to fix the mask to the effective lens region, a portion for bridging each mask is required, and a spacer cannot be scattered on that portion. In addition, it is necessary to check the remaining spacers in the effective lens region, and there is a problem that the number of processes is greatly increased.

  Therefore, the present invention eliminates the above-mentioned problems and mixes a spacer around the effective lens area instead of the in-cell spacer in order to produce a uniform gap in the entire cell configuration including the heater. Even if a heater for low-temperature countermeasures is provided around the effective lens area, the seal is formed in the vicinity of the effective lens area without being affected by the film thickness of the heater. An object of the present invention is to provide a liquid crystal lens having a uniform heater structure that is easy to arrange and manufacture and has less cell gap unevenness in the cell.

  In order to solve the above-described problems and achieve the object, the liquid crystal lens of the present invention basically adopts the following configuration.

  The liquid crystal lens according to the present invention has an effective lens region for functioning as a variable focus lens and a transparent substrate provided with a heater in the vicinity of the outer region of the effective lens region, bonded together through a seal, and a liquid crystal layer is In the sandwiched liquid crystal lens, the seal is mixed with the first spacer, and the frame-shaped first seal provided on the outer edge of the transparent substrate and at least a heater compared to the diameter of the first spacer A second spacer having a diameter reduced by an amount corresponding to the film thickness of the first spacer, and a second seal provided inside the first seal and provided on the heater, the diameter of the second spacer Is smaller than the diameter of the first spacer by at least the film thickness of the heater.

  In the liquid crystal lens according to the present invention, the first seal described above has a closed ring shape, and the second seal described above has an opening for allowing liquid crystal to flow into the effective lens region. Is.

  With the above configuration, by injecting the liquid crystal by dropping injection into the effective lens region or outside thereof, the sealing step in the UV curing agent can be omitted, and the liquid crystal is not wasted.

  The liquid crystal lens according to the present invention is characterized in that the first seal and the second seal described above are integrally formed.

  In the liquid crystal lens according to the present invention, the effective lens region described above has a substantially circular shape, and the second seal is formed in a curved shape along the outer shape of the effective lens region. Is.

  By adopting the above configuration, the uniformity of the cell gap of the liquid crystal lens and the generation of astigmatism with respect to light passing through the liquid crystal lens can be minimized.

  In the liquid crystal lens according to the present invention, the above-described second seal is divided into an even number, and the divided pairs of the second seals are arranged symmetrically with respect to the lens center of the effective lens region. It is a feature.

  With the above configuration, the uniformity of the cell gap and the occurrence of the astigmatism can be minimized.

  The liquid crystal lens according to the present invention is characterized in that the inner wall surface adjacent to the effective lens region in the second seal described above is disposed so as to be equidistant from the lens center in the effective lens region. It is.

  According to the liquid crystal lens of the present invention, a spacer for easily providing a cell gap is disposed on the heater in the vicinity of the effective lens region while having a heater structure for preventing a decrease in the response speed of the liquid crystal in a low temperature environment. Therefore, compared with the conventional configuration, the cell gap in the effective lens region can be regulated to the target cell gap. Further, even if a transparent electrode for functioning as a variable focus lens is arranged around the effective lens region, the transparent electrode can be made thin and high resistance, so that the transmittance can be increased. The spacer arrangement in the vicinity of the effective lens region can be performed in a normal seal forming process, so that a new process is not added and the liquid crystal lens of the present invention can be easily manufactured.

  In addition, according to the liquid crystal lens of the present invention, there is no spacer in the effective lens region, and the problem of transmission diffusion, the problem of diffraction, and the problem of occurrence of aberration due to orientation disturbance do not occur.

  Exemplary embodiments of a liquid crystal lens cell according to the present invention and an electronic apparatus equipped with the same will be described below in detail with reference to the accompanying drawings.

  First, a configuration example of the liquid crystal lens cell of the present invention will be described. FIG. 1A and FIG. 1B are a cross-sectional view and a front view showing a cell configuration of a liquid crystal lens, respectively.

As shown in FIG. 1A, the liquid crystal lens 1a according to the present invention includes, for example, pattern electrodes 24, 25, 2 each having a predetermined pattern formed on the inner surface of three opposing transparent substrates 12, 13, and 14.
6 and 27 are bonded through a seal so as to face each other, and a heater 21 is formed on a part of the pattern electrode 25 by patterning. On the pattern electrodes 24 to 27 and the heater 21, alignment films 18a and 18b for aligning liquid crystals are formed by rubbing treatment.

  The liquid crystal lens 1a is a homogeneous alignment liquid crystal cell in which, for example, p-type liquid crystals 10 and 11 are sealed so that the director direction in which the liquid crystals 10 and 11 are aligned with each other is 90 °. In this figure, the positional relationship in which the director directions of the liquid crystals 10 and 11 are shifted by 90 ° is such that the liquid crystal 10 is directed perpendicular to the paper surface and the liquid crystal 11 is directed from the lower left to the upper right. However, the present invention is limited to this. It is not a thing. In addition, although the liquid crystals 10 and 11 are in homogeneous alignment, they may be twist alignment, bend alignment, splay alignment, or hybrid alignment, or may be n-type liquid crystal and vertical alignment.

  Moreover, the seal | sticker which adhere | attaches the transparent substrates 12-14 is a frame shape which mixes the spacer 17a which determines the cell gap provided in the outer edge part of the transparent substrates 12-14 as shown to Fig.1 (a) (b). The first seal 15 and the heater 21 for heating the liquid crystal inside the first seal 15 and near the outside of the effective lens region 20 for phase modulation of the liquid crystals 10 and 11 are circular. A second seal 16a is formed so that a spacer 17b having a diameter smaller than the spacer 17a mixed in the first seal 15 by the film thickness of the heater 21 is mixed along the shape of a certain effective lens region 20. Yes. A second seal 16a in which a spacer 17c for determining a cell gap of the liquid crystal 10 is mixed is arranged between the transparent substrates 13 and 14 without the heater 21.

  In the drawing, the diameter of the spacer 17b is smaller than that of the spacer 17a by the film thickness of the heater 21 and the film thickness of the alignment film 18a on the transparent substrate 12 and 13 side. The spacer diameter may be reduced including the thickness of the electrodes 24 and 25.

  In addition, the spacer 17b may be recessed into the alignment film 18a or the heater 21 depending on the degree of pressure applied at the time of manufacturing the panel. It is preferable to increase the diameter of the spacer 17b.

  Thus, in the liquid crystal lens 1a of the present invention, the heater 21 exists around the effective lens region 20, but the spacer 17b considering the thickness of the heater 21 is mixed in the second seal 16a. A variable focus lens having excellent surface accuracy can be obtained. Further, in the drawing, for convenience, the seal 16a is completely accommodated in the width of the heater 21, but since the cell gap by the spacer is determined at the narrowest gap, the second seal 16a inside the width of the heater 21 is not necessarily provided. There is no need to pay.

  Further, as shown in the drawing, the second seal 16a in the liquid crystal lens 1a has a sealed space between the first seal 15 and the second seal 16a so that the liquid crystals 10 and 11 are injected. In order not to make it, it is divided into two even numbers and arranged so as to have a point-symmetrical relationship with respect to the lens center in the effective lens region 20.

  The first and second seals 15 and 16a disposed between the transparent substrates 12 and 13 and the transparent substrates 13 and 14, respectively, are overlapped at the same position as shown in FIG. Yes. Accordingly, the cell gap between the transparent substrates 12 and 13 and between the transparent substrates 13 and 14 can be made uniform, and the flatness of the cells can be obtained, so that it passes through the liquid crystal lens 1a. Generation of astigmatism with respect to light can be suppressed as much as possible.

  If the divided second seals 16a are arranged at different distances from the lens center, or if the odd number of the second seals 16a are arranged irregularly at irregular intervals, the liquid crystal 10 existing in the effective lens region 20, As the surface accuracy of 11 decreases, the possibility of aberration occurring in the light passing through the liquid crystal lens 1a increases. In particular, when there are two liquid crystal layers and the position where the second seal 16a is arranged in the first and second layers in a cell using three transparent substrates 12 to 14, the liquid crystal lens 1a At the time of manufacturing, in particular, unevenness occurs in the pressure distribution during pressurization in the bonding process of the transparent substrates 12 to 14, and the surface accuracy of the liquid crystals 10 and 11 is deteriorated. As a result, there is a problem that aberrations are always generated in the light passing through the liquid crystal lens 1a.

  In FIGS. 1A and 1B, glass fibers are used as the spacers 17a to 17c, but the spacers 17a to 17c are not particularly limited, and may be silica beads, plastic beads, or conductive particles.

Here, a manufacturing method of the liquid crystal lens 1a of the present invention will be described. The liquid crystal lens 1a can be manufactured by the following steps.
First, a second seal 16a in which a predetermined amount of a spacer 17b having a diameter reduced from the target cell gap by the thickness of the heater 21 and the thickness of the alignment film 18a is mixed, and the alignment film from the target cell gap diameter. A second seal 16a in which a predetermined amount of spacer 17c having a diameter reduced by the film thickness of 18b is mixed, and a first seal 15 in which a predetermined amount of spacer 17a having a target cell gap diameter is mixed are used, for example, by screen printing. Printing is performed on the surfaces of the transparent substrates 12 and 14, respectively.

  Then, the transparent substrates 12 to 14 are overlapped, and the first and second seals 15 and 16a are applied by applying a predetermined pressure while applying heat to the first and second seals 15 and 16a by hot pressing. It hardens | cures and adhesive force increases and it adhere | attaches with the transparent substrates 12-14, maintaining the cell gap of the particle size of spacer 17a-17c. The first and second seals 15 and 16a may be patterned by a dispenser.

  As described above, the second seal 16a is arranged in the vicinity of the effective lens region 20 in the cell as a cell gap correction seal in consideration of the offset of the film configuration at the seal arrangement place while having the heater configuration. The distance between the lens region 20 and the spacers 17b and 17c can be minimized, and cell gap unevenness can be minimized.

  In the present invention, since there are many regions for regulating the cell gap between the transparent substrates 12 to 14, the amount of deformation of the transparent substrates 12 to 14 should be reduced even if an external stress is applied. Can do.

  In the seal printing method, for example, the second seal 16a is printed on the transparent substrate 12, the first seal 15 is printed on the transparent substrate 13, and then the transparent substrates 12 to 14 are overlapped. Different types of sealing materials can be incorporated into the same cell. For this reason, regarding the 1st seal | sticker 15 and the 2nd seal | sticker 16a, not only the diameter of the spacers 17a-17c can be changed but the mixing ratio and the sealing material can also be changed.

  For the first seal 15 and the second seal 16a, a thermosetting epoxy resin, a UV curable epoxy resin, or the like can be used. Moreover, you may form combining the material from which the 1st seal | sticker 15 and the 2nd seal | sticker 16a differ.

The shape of the first seal 15 is a quadrangle in FIG. This shape is not particularly limited, but a large number of cells are simultaneously formed in a large size, and in a strip-shaped cell having a plurality of cells arranged in a line, liquid crystal is simultaneously applied to the plurality of cells. When injecting, it is desirable to have a shape that forms a seal along the outer shape of the transparent substrates 12 to 14, but other shapes may be used.

  Further, in FIG. 1B, the first seal 15 and the second seal 16a are arranged separately without being connected, but the first and second seals 15 and 16a are integrally connected to each other. You may form in. At that time, in order to allow the liquid crystals 10 and 11 to enter the effective lens region 20, it is important to provide a liquid crystal channel (opening) communicating with the liquid crystal injection port.

  As an injection method for the liquid crystals 10 and 11, after setting an empty cell in the chamber and evacuating it, the liquid crystal injection port provided in the first seal 15 is immersed in the liquid crystal and returned to atmospheric pressure. The liquid crystal lens 1a can be manufactured by a vacuum injection method in which the liquid crystals 10 and 11 are injected into the cell. When this method is adopted, it is necessary to secure a liquid crystal channel (opening) as described above. Then, after injecting liquid crystal into the inner region of the first seal 15 including the lens effective region 20, a UV curable sealing agent 19 is applied to the injection port, and the sealing material 19 is irradiated with UV to be cured. Thus, the liquid crystal lens 1a of the present invention is completed.

  The liquid crystal lens 1a of the present invention can also be manufactured by a liquid crystal dropping injection method using a dispenser or the like. In this case, although not shown, the first seal 15 has a closed ring shape, and the second seal 16 a has a liquid crystal channel (opening) for allowing the liquid crystals 10 and 11 to flow into the effective lens region 20. And Thus, when the liquid crystal dropping injection method is employed with the first seal 15 as a closed ring structure, the sealing material 19 is not necessary. In addition, if the liquid crystal dropping injection method is employed, the required amount of liquid crystal can be injected only into the region within the seal, thereby eliminating unnecessary use of the liquid crystal.

  The arrangement form of the second seal 16a is not particularly limited as long as it is in the vicinity of the effective lens region 20, and may be a linear shape or a point shape, which will be described later, but it follows the outer shape of the effective lens region 20. A curved shape is desirable.

  As described above, it is desirable to provide the second seal 16a as close to the effective lens region 20 as possible. However, generally, in the vicinity of the seal, the components of the seal are formed to spread before being cured during pressure firing. There may be a problem, a problem that the liquid crystal is not aligned well in the vicinity of the seal, and a problem such as a disclination that is an alignment continuity defect of the liquid crystal molecules. Therefore, the effective lens region 20 and the second seal 16a It is better to take some margin in the arrangement position in consideration of the above matters.

  As described above, the liquid crystal lens 1 a according to the present invention is a spacer for providing a target cell gap in consideration of the film thickness of the heater 21 even when the heater 21 is easily present in the vicinity of the effective lens region 20. Since 17b to 17c are arranged, it is possible to regulate the cell gap in the effective lens region 20 to a target cell gap as compared with the conventional configuration while having a low temperature countermeasure heater configuration. The arrangement of the spacers 17b to 17c in the vicinity of the effective lens region 20 can be performed in a normal seal forming process, so that the liquid crystal lens 1a can be easily manufactured without adding a new process. .

  In addition, according to the liquid crystal lens 1a, there is no spacer in the effective lens region 20, which frequently occurs in the conventional manufacturing method, and there is a problem of transmission diffusion and diffraction that frequently occur in the conventional configuration. This problem does not occur, and the problem of aberration due to orientation disturbance does not occur.

Next, another configuration example of the liquid crystal lens of the present invention will be described. FIG. 2 is a diagram showing another configuration example of the liquid crystal lens of the present invention.
The liquid crystal lens 1b shown in FIG. 2 differs from the configuration example shown above only in the shape of the second seal, and the other configurations are the same. Therefore, in the following description, the difference in the present embodiment will be mainly described, and description of other common members will be omitted.

  As shown in FIG. 2, the liquid crystal lens 1b has four second seals 16b that are substantially linear. This configuration is particularly effective when a smaller liquid crystal lens 1b is used.

  In order to reduce the external size of the liquid crystal lens and increase the cell gap, in the liquid crystal lens 1a shown in FIG. 1B in Example 1, the second seal 16b is formed in a desired circular shape in screen printing. May be difficult. Therefore, in the liquid crystal lens 1b in this embodiment, as shown in FIG. 2, the substantially linear second seal 16b is divided into an even number (divided into four in this figure) to obtain an effective lens area. It is arranged on the heater 21 in the vicinity of 20. Thus, by making the shape of the second seal 16b in the liquid crystal lens 1b substantially linear, the uniformity of the cell gap is improved, and the generation of astigmatism with respect to the light passing through the liquid crystal lens 1b is minimized. can do.

Next, a modification of the liquid crystal lens of the present invention shown in FIG. 2 will be described. FIG. 3 is a diagram showing a modification of the liquid crystal lens 1b described above.
The liquid crystal lens 1c in the present modification is different in only the shape of the first seal 15 and the width of the heater 21 in the liquid crystal lens 1b shown in FIG. 2, and the other configurations are the same. Therefore, in the following description, the difference in this modification is mainly demonstrated, and the description about another common member is omitted.

  As shown in FIG. 3, the liquid crystal lens 1 c has a configuration in which the outer edge portion of the second seal 16 c and the first seal 15 that is equidistant from the lens center in the effective lens region 20 are eliminated. For example, in the liquid crystal lens 1c, the heater 21 has a wide width. In this way, when the width of the heater 21 is widened without changing the external size of the liquid crystal lens, the thickness of the heater 21 is not taken into consideration if the first seal 15 is disposed on the heater 21 so as to overlap. The spacer 17a is disposed on the heater. In such a structure, the portion where the heater 21 and the first seal 15 are overlapped with each other has a poor surface accuracy because the cell gap is increased by the thickness of the heater 21. This is not preferable. On the other hand, as described above, the liquid crystal lens 1c in the present modification has a configuration in which the first seal 15 that is equidistant from the distance between the lens center and the outer edge of the second seal 16c is removed. The deterioration of the surface accuracy of the cell can be minimized.

Next, another modification of the liquid crystal lens of the present invention shown in FIG. 2 will be described. FIG. 4 is a view showing another modification of the liquid crystal lens 1b shown in FIG.
In the liquid crystal lens 1d in the present modified example, the shape of the second seal and the shape of the heater 21 in the liquid crystal lens 1b shown in FIG. The configuration is the same. Therefore, in the following description, the difference in this modification is mainly demonstrated, and the description about another common member is omitted.

As shown in FIG. 4, the liquid crystal lens 1 d has a D-cut for the heater 21 on the inlet side to narrow a part of the heater width, and a second seal 16 d is added to the liquid crystal lens 1 c shown in FIG. 3. In contrast, two are added. And the 2nd seal | sticker 16d distribute | arranged up and down with respect to the paper surface is connected and integrated with the 1st seal | sticker 15 so that it may not be arrange | positioned on the heater 21. FIG. When the first seal 15 is arranged on the heater 21 so as to overlap the spacer 17a mixed in the first seal 15, the spacer 17a not considering the thickness of the heater 21 is placed on the heater 21. As a result, the cell gap of the portion becomes thicker than other portions. Therefore, it is important to prevent the first seal 15 and the heater 21 from being overlapped in consideration of deterioration of surface accuracy. The individual second seals 16d are arranged so that all the inner wall surfaces on the lens center side of the second seal 16d are equidistant from the lens center.

  In order to improve surface accuracy, the liquid crystal lens 1d has a balance with the D-cut surface of the heater 21 and the heater width in order to dispose as many second seals as possible at an equal distance from the effective lens region 20. For this reason, the second seal 16d is not completely accommodated on the heater 21, but the cell gap of the liquid crystal lens 1d is determined by the spacer 17b in the second seal 16d on the heater 21, so that the heater The second seal 16d provided so as to protrude from 21 does not affect the regulation of the cell gap.

  Also, depending on the balance with the heater shape, by using the liquid crystal lens 1d in the present embodiment, it is possible to obtain a lens with improved cell gap accuracy compared to the previous embodiment.

  With the configuration of the liquid crystal lenses 1b to 1d described above, in addition to the effects peculiar to the present invention described in the first embodiment, even if the outer size is made smaller, particularly small and the cell gap is thick, The effect can be maintained.

Next, still another configuration example of the liquid crystal lens of the present invention will be described. FIG. 5 is a diagram showing still another configuration example of the liquid crystal lens of the present invention.
The liquid crystal lens 1e shown in FIG. 5 differs only in the shape of the second seal in the liquid crystal lenses 1a and 1b in the first and second embodiments described above, and the other configurations are the same. Therefore, in the following description, the difference in the present embodiment will be mainly described, and description of other common members will be omitted.

  As shown in FIG. 5, the liquid crystal lens 1 e is arranged on the outer periphery of the effective lens region 20, and the respective dotted second seals 16 e are arranged at equidistant positions from the lens center in the effective lens region 20. It has become the composition. These point-like second seals 16e are arranged on the heater 21 so as to be point-symmetric at positions equidistant from the lens center in the effective lens region 20.

  Thus, by arranging a plurality of second seals 16e symmetrically with respect to the center of the lens, in addition to the effects of the first embodiment, the shape of the second seal 16e having the curvature shown in the first embodiment can be obtained. The problem that it is difficult to obtain a desired circular shape in screen printing at the time of forming can be solved.

  Further, the second seal 16e is divided into point shapes (in the figure, divided into 8 even numbers) so that a seal having a shape close to an arc shape as a collection of points can be easily obtained. Therefore, it is possible to reduce the astigmatism as much as possible with respect to the uniformity of the cell gap and the light transmitted through the liquid crystal lens 1e. The liquid crystal lens 1e has a particularly effective configuration when it is necessary to reduce the outer shape of the cell.

Next, still another configuration example of the liquid crystal lens of the present invention will be described. FIG. 6 is a diagram showing still another configuration example of the liquid crystal lens of the present invention.
The liquid crystal lens 1f shown in FIG. 6 of the present embodiment is different from the configuration example shown above only in the shape of the second seal, and the other configurations are the same. Therefore, in the following description, the difference in the present embodiment will be mainly described, and description of other common members will be omitted.

  As shown in FIG. 6, the liquid crystal lens 1 f has a configuration in which the shape of the second seal 16 f disposed outside the effective lens region 20 is a linear shape. Further, in this figure, the second seal 16f is not completely placed on the heater 21, but a problem arises because the cell gap is determined by the spacer 17b in the second seal 16f on the heater 21. Absent.

  In this way, by arranging the two second seals 16f to be symmetrical at positions equidistant from the center of the lens in the effective lens region 20, as described in the other embodiments, the effective lens Although the distance from the region 20 to the inner wall of the second seal 16f varies, the cell gap uniformity can clearly be improved as compared with the conventional configuration.

Next, still another configuration example of the liquid crystal lens of the present invention will be described. FIGS. 7A and 7B are diagrams showing still another configuration example of the liquid crystal lens of the present invention.
The liquid crystal lenses 1g and 1h shown in FIG. 7 of the present embodiment are different from each other only in the shape of the second seal in the configuration example described above, and the other configurations are the same. Therefore, in the following description, the difference in the present embodiment will be mainly described, and description of other common members will be omitted.

  As shown in FIG. 7A, the liquid crystal lens 1g is disposed on the heater 21 integrally with the second seal 16g surrounding the outer periphery of the effective lens region 20 and at a distance from the first seal 15. A configuration example is shown.

  In the present configuration example, the shape of the second seal 16g has a curved surface shape, so that it becomes difficult to obtain a desired seal shape when the outer dimension of the cell is reduced. Even if the second seal 16g is divided into a plurality of even numbers and not divided after an even number, the effects specific to the present invention described in the first embodiment can be obtained.

  If the heater 21 and the second seal 16g are positioned so as to overlap at least the area for determining the cell gap, the second seal 16g may be formed so as to protrude from the heater 21, or the heater 21 and the second seal 16g. The second seal 16g may be partially covered.

  Further, like the liquid crystal lens 1h shown in FIG. 7 (b), the second seal 16h divided into three is provided on the outer periphery of the effective lens region 20 from the lens center to the inner wall surface of the second seal 16h. It is good also as a form each arrange | positioned so that distance may become equal.

  As shown in FIG. 7B, even when three second seals 16h are arranged on the outer periphery of the effective lens region 20, the first embodiment is similar to the embodiment shown in FIG. The effects unique to the present invention described can be obtained.

As described above, the present invention has a configuration in which a heater is present in order to efficiently heat around the effective lens region as a countermeasure for low temperature, and the heater film thickness around the effective lens region instead of the in-cell spacer. By forming a seal mixed with a spacer that takes into account the difference in thickness of the film structure due to, etc., it is useful for manufacturing a uniform liquid crystal lens with less gap unevenness in the cell easily, In particular, it has a quality suitable as an optical component for a camera that is mounted on a camera, a digital camera, a movie camera, a camera unit of a camera-equipped mobile phone, a car, etc. and used for a monitor for backward confirmation.

  Further, the configuration of the liquid crystal lens of the present invention is applicable not only to a liquid crystal panel functioning as a lens, but also to a liquid crystal optical element used for correcting wavefront aberration that occurs when recording and reproducing an optical disk. It is.

It is sectional drawing and the front view which show the structural example of the liquid-crystal lens concerning this invention. It is a figure which shows the other structural example of the liquid crystal lens concerning this invention. It is a figure which shows the modification in the liquid crystal lens concerning this invention. It is a figure which shows the other modification in the liquid crystal lens concerning this invention. It is a figure which shows the further another structural example of the liquid crystal lens concerning this invention. It is a figure which shows the further another structural example of the liquid crystal lens concerning this invention. It is a figure which shows the further another structural example of the liquid crystal lens concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a-1h Liquid crystal lens 10 Liquid crystal 11 Liquid crystal 12-14 Transparent board | substrate 15 1st seal | sticker 16a-16h 2nd seal | sticker 17a-17c Spacer 18a, 18b Alignment film | membrane 19 Sealing agent 20 Effective lens area | region 21 Heater 24-27 Pattern electrode

Claims (6)

In a liquid crystal lens in which an effective lens region for functioning as a variable focus lens and a transparent substrate provided with a heater in the vicinity of the outer region of the effective lens region are bonded together via a seal, and a liquid crystal layer is sandwiched between them,
The seal is mixed with a first spacer, and the frame-shaped first seal provided on the outer edge of the transparent substrate and the thickness of the heater at least as much as the diameter of the first spacer. A liquid crystal lens comprising: a second seal having a second spacer with a reduced diameter mixed therein, the second seal provided on the heater inside the first seal. The first seal has a closed ring shape,
The liquid crystal lens according to claim 1, wherein the second seal has an opening for allowing liquid crystal to flow into the effective lens region. The liquid crystal lens according to claim 1, wherein the first seal and the second seal are integrally formed. The effective lens region has a substantially circular shape, and the second seal is formed in a curved shape along the outer shape of the effective lens region. The liquid crystal lens according to one item. The second seal is divided into an even number, and the divided pairs of the second seals are arranged point-symmetrically with respect to the lens center of the effective lens region. 5. The liquid crystal lens according to any one of items 1 to 4. The inner wall surface adjacent to the effective lens region in the second seal is disposed so as to be equidistant from the lens center in the effective lens region. The liquid crystal lens described in 1.

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