JP2008209614A - Liquid crystal lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal lens that keeps a desired temperature of a liquid crystal layer and responses at a sufficient speed even at a low temperature by sufficiently reducing the resistance of a heater so as to obtain sufficient heat energy, and increasing the flexibility of pattern wiring of the heater so as to uniformly heat within the effective circle of a phase modulation electrode group, while reducing the size of the liquid crystal panel. <P>SOLUTION: A flexible circuit board is provided with an electrode wiring pattern to feed electricity to a liquid crystal panel, as well as a hole which is at least larger than a circular shape of a phase modulation electrode group, a heater disposed around the hole to heat a liquid crystal layer, and a heater wiring pattern to feed electricity to the heater. The flexible circuit board is joined to cover the surface of a transparent substrate so that the hole surrounds the periphery of the phase modulation electrode group of the liquid crystal panel, and the liquid crystal can be heated by the heater through the transparent substrate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention realizes the effective use of the phase modulation electrode group by reducing the resistance value of the heater sufficiently so that sufficient thermal energy can be obtained while reducing the size of the liquid crystal panel, and at the same time, increasing the degree of freedom of pattern wiring of the heater. The present invention relates to a liquid crystal lens that can uniformly heat a circle, maintains a liquid crystal layer at a desired temperature or higher, and responds at a sufficient speed even at a low temperature.

  Conventionally, as a focusing mechanism for changing the focal length or focal position of a camera, a method of focusing by combining two or more lenses and changing the positional relationship 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. Therefore, as a focusing mechanism that does not require a lens driving mechanism, a method of focusing by changing the refractive index of the liquid crystal lens has been proposed (see, for example, Patent Document 1).

  However, when considering a variable focus system using a liquid crystal lens, the response speed of the liquid crystal becomes a problem. It is known that a nematic liquid crystal filled in a liquid crystal lens has a slow response speed due to an increase in viscosity at a low temperature.

  Therefore, in order to increase the response speed of the liquid crystal, proposals have been made to use an alignment method called bend alignment (see Patent Document 2), or to use a ferroelectric liquid crystal with excellent high-speed response as the liquid crystal material. .

  Further, a method has been proposed in which a heater for heating the liquid crystal of the liquid crystal lens is provided in a region outside the phase modulation electrode group for changing the liquid crystal refractive index of the liquid crystal lens (see Patent Document 2).

Japanese Patent No. 3047082 (page 3-5, Fig. 1-4) Japanese Patent Laying-Open No. 2006-291243 (page 6-13, FIG. 1-11)

  However, both the bend alignment and ferroelectric liquid crystal capable of high-speed response have a small change in refractive index when the liquid crystal is ON / OFF, and therefore, when these means are used for a liquid crystal lens, the variable focus performance is remarkably inferior. There's a problem.

  Further, in the method of providing a heater for heating the liquid crystal of the liquid crystal lens in the region outside the phase modulation electrode group for changing the liquid crystal refractive index of the liquid crystal lens, in a shorter time under a limited supply voltage condition. In order to obtain sufficient thermal energy, it is necessary to sufficiently reduce the electric resistance value of the heater.

  For this reason, it is desirable to pattern a metal film having a lower resistance value as the heater material. In addition, since the resistance value is inversely proportional to the cross-sectional area of the conductor, it is desirable to make the heater pattern thicker and wider in order to reduce the resistance value.

However, in order to achieve such a configuration, it is necessary to pattern the metal film thicker and wider for the heater electrode pattern in a process different from the patterning of the phase modulation electrode group of the liquid crystal lens. This complicates the manufacturing process of the liquid crystal lens and reduces the manufacturing yield. In addition, providing a wide heater leads to an increase in the planar size of the liquid crystal lens.

  Furthermore, in order to mix the phase modulation electrode group and the heater in the same plane in the liquid crystal lens, avoid the electrode wiring pattern for supplying power to the phase modulation electrode group, and the heater wiring pattern for supplying power to the heater and the heater. I have to lay out. Therefore, this heater cannot completely surround the phase modulation electrode group having a circular outer shape, and it is difficult to uniformly heat the effective circle of the phase modulation electrode group acting as a variable focus lens.

  Therefore, the present invention solves the above-mentioned problems and realizes downsizing of the liquid crystal panel while sufficiently reducing the resistance value of the heater so that sufficient thermal energy can be obtained, and at the same time, increasing the degree of freedom of heater pattern wiring. An object of the present invention is to provide a liquid crystal lens that can uniformly heat the effective circle of a phase modulation electrode group, maintains a liquid crystal layer at a desired temperature or more, and responds at a sufficient speed even at a low temperature.

  In order to achieve the above object, the liquid crystal lens of the present invention basically adopts the following configuration.

  The liquid crystal lens of the present invention includes a first transparent substrate having a phase modulation electrode group having a circular outer shape, a second transparent substrate having a counter electrode, a liquid crystal layer sandwiched between the two transparent substrates, A liquid crystal panel provided on the surface of the first or second transparent substrate, having a phase modulation electrode group and a lead electrode for supplying power to the counter electrode, functioning as a variable focus lens, and to the phase modulation electrode group and the counter electrode A flexible circuit board having an electrode wiring pattern for supplying power, a heater for heating the liquid crystal layer via a transparent substrate, and a heater wiring pattern for supplying power to the heater; A transparent substrate is connected to the extraction electrode of the liquid crystal panel and guides incident light to the phase modulation electrode group through a hole having an inner diameter that is at least larger than the outer shape of the phase modulation electrode group. Together provided over at least one substrate surface by a heater provided on the outer periphery of the hole and is characterized in heating the liquid crystal layer.

  In the liquid crystal lens of the present invention, the hole and the inner diameter of the heater are circular, and the distance between the outer periphery of the phase modulation electrode group and the inner periphery of the heater is constant. It is characterized by this.

  The liquid crystal lens of the present invention is characterized in that the liquid crystal panel and the flexible circuit board are aligned and fixed by an alignment mark provided in the liquid crystal panel and a mark hole provided in the flexible circuit board. To do.

  The liquid crystal lens of the present invention is characterized in that a temperature sensor is disposed on the flexible circuit board and the heater is controlled in accordance with the temperature detected by the temperature sensor.

  In the liquid crystal lens of the present invention, the upper surface opposite to the mounting surface of the temperature sensor on the flexible circuit board is the side of the first or second transparent substrate in the liquid crystal panel on which the flexible circuit board is fixedly arranged. It is characterized in that it is fixed to the substrate surface located in the region of different sides.

According to the present invention, an electrode wiring pattern for supplying power to the liquid crystal panel is provided on the flexible circuit board, and a heater and a heater wiring pattern for heating the liquid crystal lens are provided, so that both can be formed by the same manufacturing process. Therefore, the heater can be formed without adding any special processing steps or parts.

  Further, since the conductor forming the heater is a conductor used in a general flexible circuit board, the thickness thereof can be made much larger than that formed on the transparent substrate of the liquid crystal lens. Therefore, when it is desired to reduce the electrical resistance of the heater in order to obtain sufficient thermal energy under limited supply voltage conditions, it is possible to flexibly cope with the need to increase the thickness and width of the heater.

  Also, by providing a heater on the flexible circuit board, the heater pattern can be freely controlled without being affected by problems such as interference with the wiring pattern of the lead-out electrode of the liquid crystal panel and an increase in the size of the liquid crystal panel due to the wiring of the heater. Can be set.

  Furthermore, the heater formed on the flexible circuit board covers the surface of the transparent substrate so as to completely surround the outer periphery of the phase modulation electrode group of the liquid crystal lens, thereby heating the effective circle more uniformly and efficiently. Can do.

  As a result, it is possible to reduce the size of the heater while lowering the resistance value of the heater, and at the same time, increase the degree of freedom of the heater wiring so that the effective circle of the phase modulation electrode group can be heated uniformly, and the liquid crystal layer can be formed in a desired manner. It is possible to provide a liquid crystal lens that is maintained at a temperature or higher and responds at a sufficient speed even at low temperatures.

  A preferred embodiment of a liquid crystal lens according to the present invention will be described below with reference to FIGS.

  First, a schematic configuration of the liquid crystal lens of the present invention will be described. FIG. 1 is an exploded perspective view showing an example of the entire configuration of the liquid crystal lens of the present invention.

  As shown in FIG. 1, the liquid crystal lens 1 of the present invention includes a liquid crystal panel 10 and a flexible circuit board 20. The liquid crystal panel 10 includes a phase modulation electrode group 101 having a circular outer shape. The liquid crystal sandwiched between both electrodes has a refractive index distribution by supplying power to the phase modulation electrode group 101 and a counter electrode (not shown). Function as a variable focus lens. The flexible circuit board 20 includes an electrode wiring pattern 21 for supplying power to the liquid crystal panel 10 and a heater 23 for heating the liquid crystal panel 10. The flexible circuit board 20 supplies power to the liquid crystal panel 10 and heats the liquid crystal panel 10. You can do it.

  Next, the configuration of the liquid crystal panel 10 shown in FIG. 1 will be described in detail with reference to FIGS. FIG. 2 is a cross-sectional view showing a configuration example of a liquid crystal panel in the liquid crystal lens of the present invention. FIG. 3 is a front view showing an example of the configuration of the liquid crystal panel in the liquid crystal lens of the present invention.

  As shown in FIG. 2, the liquid crystal panel 10 includes, for example, two opposing transparent substrates 11 and 12, and a transparent pattern electrode 13 is formed on the surface of the transparent substrate 11 facing the transparent substrate 12. A transparent counter electrode 14 is formed on the surface of the transparent substrate 12 facing the transparent substrate 11. For example, a homogeneous alignment liquid crystal layer 15 is enclosed between the transparent substrate 11 and the transparent substrate 12.

  The transparent substrate 11 has a plane shape larger than that of the opposing transparent substrate 12 and has a surface protruding at least on two sides, and is bonded to the transparent substrate 12 so as to face each other. Reference numeral 16 shown in FIG. 2 is a first protruding plane, and reference numeral 17 is a second protruding plane. A lead wiring 102 is extended to the first projecting plane 16.

  3, reference numeral 101 denotes a phase modulation electrode group having a circular outer shape, reference numeral 102a denotes an extraction electrode for supplying power to the phase modulation electrode group 101, and reference numeral 102b denotes a counter electrode 14 that does not appear in the opposing figure. This is an extraction electrode for supplying power (see FIG. 2). That is, the pattern electrode 13 formed on the transparent substrate 11 includes the phase modulation electrode group 101 and the extraction electrodes 102a and 102b. In FIG. 3, reference numeral 106 denotes a seal member, and reference numeral 107 denotes an alignment mark.

  Although not particularly limited, the phase modulation electrode group 101 is, for example, a pattern in which a plurality of C-shaped annular electrodes are arranged around the circumference of a plurality of concentric circles having different deformations around a circular center electrode. Composed. The plurality of annular electrodes are insulated spaces, and each annular electrode is connected to the extraction electrode 102a so that power can be supplied independently. The extraction electrodes 102 a are extracted from the phase modulation electrode group 101 and arranged in a line on the first projecting plane 16.

  In addition, the first projecting plane 16 is provided with a lead electrode 102b connected to the counter electrode 14 that does not appear in the drawing facing the pattern electrode 13. A common voltage is applied to the extraction electrode 102b.

  A flexible circuit board, which will be described later, is connected to the first projecting plane 16, and power is supplied to the phase modulation electrode group 101 and the counter electrode 14 of the liquid crystal panel 10.

  Various voltages are applied to the plurality of extraction electrodes 102a connected to the flexible circuit board, and the voltage values of the annular electrodes of the phase modulation electrode group 101 are different depending on the applied voltage. can do. That is, a voltage distribution is generated in the liquid crystal layer 15 by the phase modulation electrode group 101. By changing this voltage distribution, the refractive index distribution of the liquid crystal panel 10 changes, and the lens power of the liquid crystal panel 10 can be changed. Thus, the liquid crystal panel 10 can be made to function as a variable focus lens by making it into a convex lens, parallel glass, or concave lens.

  The seal member 106 seals the peripheral edge of the phase modulation electrode group 101 having a circular outer shape, and the thickness of the liquid crystal layer 15 (see FIG. 2) in the liquid crystal panel 10 is dispersed in the seal member 106. It is kept constant by the spacer member that does not.

  The alignment mark 107 is a positioning mark provided on the transparent substrate 11 or the transparent substrate 12. As the shape of the alignment mark 107, for example, as shown in FIG. 3, two circular patterns are provided at a predetermined distance. The mark is formed by patterning simultaneously with the same material as the electrode film when pattern electrode 13 or counter electrode 14 is patterned. Moreover, you may provide by means, such as printing, in a post process.

Although it does not specifically limit in the liquid crystal lens of this invention, The dimension of the liquid crystal panel 10 is shown below as an example.
The length of one side of the transparent substrates 11 and 12 is about several mm to several tens of mm, for example, 6 mm. The thickness of the transparent substrates 11 and 12 is about several hundred μm, for example, 300 μm. The thickness of the liquid crystal layer 15 is about several μm to several tens of μm, for example, 25 μm. The diameter of the phase modulation electrode group 101 is about several mm, for example, 2.5 mm. The alignment mark 107 has a diameter of about several hundred μm, for example, 300 μm.

  Next, the flexible circuit board 20 of the present invention will be described in detail with reference to FIG. FIG. 4 is a front view showing an example of a flexible circuit board in the liquid crystal lens of the present invention.

  In general, the flexible circuit board 20 has a structure in which a conductive foil having a thickness of about 10 μm to 50 μm is formed on the surface of a film-like insulator having a thickness of 30 μm to 150 μm, and is flexible and can be greatly deformed. Printed circuit board. Polyimide is used as the insulator, and copper is used as the conductor.

  4, reference numeral 21 denotes an electrode wiring pattern for supplying power to the liquid crystal panel 10 (see FIG. 3), reference numeral 22 denotes a hole provided corresponding to the phase modulation electrode group 101 of the liquid crystal panel 10, and reference numeral 23. Is a heater for heating the liquid crystal panel 10, reference numeral 24 is a heater wiring pattern for supplying power to the heater 23, reference numeral 25 is a positioning mark hole provided corresponding to the alignment mark 107 of the liquid crystal panel 10, Reference numeral 26 is a temperature sensor for detecting the temperature of the liquid crystal panel 10, reference numeral 27 is a temperature sensor wiring pattern for supplying power to the temperature sensor 26, reference numeral 28 is a mud provided between the electrode wiring pattern 21 and the hole 22, Respectively.

  The electrode wiring pattern 21 is a metal wiring pattern provided corresponding to the extraction electrodes 102a and 102b shown in FIG. 3 in order to supply power to the liquid crystal panel 10. The number, the wiring pitch, and the pattern width are the same as those of the extraction electrodes 102 a and 102 b of the liquid crystal lens 10.

  The hole 22 has a hole that is at least larger than the outer shape of the phase modulation electrode group 101 of the liquid crystal panel 10. The shape of the hole 22 is not particularly limited. For example, it is desirable that the hole 22 be a circular hole slightly larger than the circular outer shape of the phase modulation electrode group 101 of the liquid crystal panel 10.

  The heater 23 heats the liquid crystal layer 15 via the transparent substrate 11 or the transparent substrate 12 shown in FIG. 2, and is made of the same process as the electrode wiring pattern 21 and the metal on the flexible circuit board 20 formed by the same material. It is a wiring pattern. That is, by forming the heater 23 on the flexible circuit board 20, it is extremely easy to add a process for forming the heater to the manufacturing process of the liquid crystal panel 10 or to add a new part for the heater. The heater 23 can be formed.

  The shape of the heater 23 is not particularly limited. For example, as shown in FIG. 4, the heater 23 is similar in shape to the hole 22, has a circular shape with a constant width surrounding the hole 22, and is a heater for supplying power to the heater 23. The wiring pattern 24 is drawn from both the left and right ends of the heater 23. At this time, the pattern width of the heater 23 is set to be narrower than the pattern width of the heater wiring pattern 24. In the wiring path including the heater, the part where the pattern width is partially narrower generates more heat due to the increased current density. Therefore, by making the pattern width of the heater 23 narrower than others, only the circular part of the heater is formed. Can be heated more selectively. Further, by making the pattern width in the circular path of the heater 23 constant, heat can be generated uniformly in the path of the heater 23.

  Another advantage of forming the heater 23 on the flexible circuit board 20 is that the conductor thickness of the heater 23 can be set relatively easily. For example, when the heater is formed on the transparent substrate of the liquid crystal panel 10 by vapor deposition or plating, the thickness is generally 1 μm or less, whereas when the heater is formed on the flexible circuit board 20, the general flexible Considering the conductor thickness of the circuit board, the thickness can be about 10 μm to 50 μm.

  In other words, when it is desired to reduce the electrical resistance of the heater in order to obtain sufficient thermal energy under limited supply voltage conditions, it is possible to flexibly cope with the need to increase the thickness and width of the heater. As a result, the width, thickness, and routing of the heater can be set flexibly, and a smaller and more efficient heater 23 can be realized.

  The mark hole 25 is a hole for positioning the flexible circuit board 20 and the liquid crystal panel 10. It is arranged at a position corresponding to the alignment mark 107 provided on the liquid crystal panel 10. It is important that the size of the mark hole 25 is set slightly larger than the diameter of the alignment mark 107. That is, when the mark hole 25 of the flexible circuit board 20 and the alignment mark 107 of the liquid crystal panel 10 are overlapped, the alignment mark 107 is set to appear concentrically at the opening of the mark hole 25.

  The temperature sensor 26 detects the temperature of the liquid crystal panel 10 and is mounted on the flexible circuit board 20 side here. As a result, it is not necessary to separately create a wiring pattern for the temperature sensor 26 on the liquid crystal panel 10 side, so that not only the liquid crystal panel 10 can be reduced in size, but also the pattern layout and shape of the extraction electrodes of the liquid crystal panel 10 can be further increased. It becomes possible to consider flexibly. Further, for example, when the temperature detection circuit requires an accessory component such as a capacitor or a resistor other than the temperature sensor 26, the wiring and mounting position can be flexibly handled by similarly mounting on the flexible circuit board 20. be able to.

  The mud 28 is an extraction window for easily bending the flexible circuit board 20 when the liquid crystal panel 10 and the flexible circuit board 20 are connected. However, the mud 28 may not be provided.

  Next, the structure of the liquid crystal lens 1 of the present invention will be described in detail with reference to FIGS. FIG. 5 is a front view showing an example of a state in which the liquid crystal panel 10 and the flexible circuit board 20 are connected, and FIG. 6 is a cross section showing an example of a state in which the liquid crystal panel 10 and the flexible circuit board 20 are connected. FIG.

  To connect the liquid crystal panel 10 and the flexible circuit board 20, the flexible circuit board 20 is first placed and fixed on the transparent substrate 12 with the alignment mark 107 and the mark hole 25 positioned. As a method for fixing the flexible circuit board 20 and the liquid crystal panel 10, for example, the outer peripheral portion of the transparent substrate 12 and the surface of the flexible circuit board 20 are fixed by UV bonding.

  Next, the lead electrodes 102a and 102b exposed on the first protruding plane 16 of the liquid crystal panel 10 and the electrode wiring pattern 21 of the flexible circuit board 20 are aligned with a jig or the like and then electrically connected. To do. The connection method here can be performed by, for example, thermocompression bonding using an anisotropic conductive sheet. As a result, the flexible circuit board 20 is fixed to the two surfaces of the transparent substrate 12 of the liquid crystal panel 10 and the first projecting plane 16. As shown in FIG. 6, the two surfaces have a level difference corresponding to the thickness of the transparent substrate 12 and the thickness of the liquid crystal layer 15, but the flexible circuit board 20 is flexible, as shown in FIG. By bending near the step, it is possible to connect to different heights.

  Here, in a state where the liquid crystal panel 10 and the flexible circuit board 20 are positioned and fixed at predetermined positions, the hole portions 22 of the flexible circuit board 20 are disposed so as to surround the phase modulation electrode group 101. . Further, since the hole 22 is set to be at least larger than the outer shape of the phase modulation electrode group 101, the flexible circuit board 20 fixed to the upper surface of the transparent substrate 12 prevents light from passing through the phase modulation electrode group 101. There is nothing.

If the flexible circuit board 20 is fixedly arranged on the liquid crystal panel 10 in this way, the heater 23 is brought into contact with the phase modulation electrode group 101 so as to surround it. At this time, as shown in FIG. 5, the heater 23 has a circular shape in which the inner circumference of the heater 23 has a constant distance from the outer circumference of the phase modulation electrode group 101. It has a circular shape that is constant in width with the inner periphery. In this way, by making the heater 23 circular with a constant curvature and a constant width, unevenness in heat generation in the heater can be kept low. Also, by arranging the heater 23 and the phase modulation electrode group 101 so that the distance between them is constant, the heat generated by the heater 23 is efficiently transferred into the circle of the phase modulation electrode group 101 via the transparent substrate 12. As a result, the liquid crystal layer 15 on the phase modulation electrode group 101 functioning as a variable focus lens can be uniformly heated.

  The temperature sensor 26 is placed on the second projecting plane 17 of the liquid crystal panel 10 with the upper surface opposite to the mounting surface on the flexible circuit board 20 being fixed. The method for fixing the temperature sensor 26 is not particularly limited. For example, the temperature sensor 26 is fixed using a silicone adhesive having good thermal conductivity. In this way, the temperature sensor 26 detects the temperature on the second projecting plane 17 when the liquid crystal panel 10 is heated by the heater 23. Further, in order to detect the temperature of the liquid crystal layer 15 heated by the heater 23 as accurately as possible, the position of the temperature sensor 26 is a position where the temperature difference from the liquid crystal layer 15 is as small as possible, that is, the second projecting plane 17. It is desirable to fix it at a position as close as possible to the above phase modulation electrode group 101.

  By arranging the temperature sensor 26 in this way, the power supply to the heater 23 is controlled so that the temperature of the liquid crystal layer 15 becomes a predetermined value according to the temperature of the liquid crystal layer 15 detected by the temperature sensor 26. . The liquid crystal layer 15 can be maintained at a predetermined temperature even in a low temperature environment, and a liquid crystal lens whose response speed does not change even at a low temperature can be realized.

  In the above description, a configuration example in which the temperature sensor 26 is placed on the side (second projecting plane 17) facing the region (first projecting plane 16) where the extraction electrodes 102a and 102b of the liquid crystal panel 10 are formed. Although shown, the liquid crystal lens of the present invention is not limited to this, and the temperature sensor 26 may be provided in a region adjacent to the first projecting surface 16.

  As described above, in the liquid crystal lens 1 of the present invention, the heater 23 is provided on the flexible circuit board 20, so that the liquid crystal panel can be interfered with the wiring pattern of the extraction electrodes 102a and 102b of the liquid crystal panel 10 and the wiring of the heater. The heater pattern can be set freely without being affected by problems such as an increase in size. In addition, when it is desired to reduce the electrical resistance of the heater in order to obtain sufficient thermal energy under the condition of a limited supply voltage, even if it is necessary to increase the thickness or width of the heater, it is possible to flexibly cope with it. As a result, a smaller and more efficient heater can be realized.

  Further, in the liquid crystal panel 10, it is not necessary to lay out the heater and temperature sensor patterns, and not only can the size be reduced, but also the process of forming the heater and the process of mounting the temperature sensor are not required. This simplifies the process and improves the yield.

  The liquid crystal lens according to the present invention is useful for an automatic focusing device using a lens having a variable focus, and is mounted on a camera, a digital camera, a movie camera, a camera unit of a camera-equipped mobile phone, a car, etc. This is suitable for the structure of a lens unit such as a camera used for a monitor for an automobile, a camera part of an endoscope, and the like.

It is a disassembled perspective view which shows an example of the whole structure of the liquid-crystal lens of this invention. It is sectional drawing which shows the structural example of the liquid crystal panel in the liquid crystal lens of this invention. It is a front view which shows the structural example of the liquid crystal panel in the liquid crystal lens of this invention. It is a front view which shows an example of the flexible circuit board in the liquid crystal lens of this invention. It is a front view which shows an example of the state which connected the liquid crystal panel and flexible circuit board in the liquid crystal lens of this invention. It is sectional drawing which shows an example of the state which connected the liquid crystal panel and flexible circuit board in the liquid crystal lens of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Liquid crystal panel 11, 12 Transparent substrate 13 Pattern electrode 14 Counter electrode 15 Liquid crystal layer 16 1st protrusion plane 17 2nd protrusion plane 20 Flexible circuit board 21 Electrode wiring pattern 22 Hole 23 Heater 24 Heater wiring pattern 25 Mark hole 26 Temperature sensor 27 Temperature sensor wiring pattern 28 Mad 101 Phase modulation electrode group 102, 102a, 102b Lead electrode 106 Seal member 107 Alignment mark

Claims (5)

A first transparent substrate having a phase-modulating electrode group having a circular outer shape; a second transparent substrate having a counter electrode; a liquid crystal layer sandwiched between the first and second transparent substrates; A liquid crystal panel provided on the surface of the second transparent substrate, having a lead electrode for supplying power to the phase modulation electrode group and the counter electrode, and functioning as a variable focus lens;
A flexible circuit board comprising: an electrode wiring pattern for supplying power to the phase modulation electrode group and the counter electrode; a heater for heating the liquid crystal layer via the transparent substrate; and a heater wiring pattern for supplying power to the heater. With
In the flexible circuit board, the electrode wiring pattern is connected to an extraction electrode of the liquid crystal panel, and is incident on the phase modulation electrode group through a hole having an inner diameter larger than the outer shape of the phase modulation electrode group. A liquid crystal lens, which is provided so as to cover at least one substrate surface of the transparent substrate so as to guide light, and the liquid crystal layer is heated by a heater provided on the outer periphery of the hole. The inner diameter shape of the hole and the heater is a circular shape,
The liquid crystal lens according to claim 1, wherein the interval between the outer periphery of the phase modulation electrode group and the inner periphery of the heater is arranged to be constant. The liquid crystal panel and the flexible circuit board are aligned and fixed by an alignment mark provided in the liquid crystal panel and a mark hole provided in the flexible circuit board. 2. A liquid crystal lens according to 2. 4. The liquid crystal lens according to claim 1, wherein a temperature sensor is disposed on the flexible circuit board, and the heater is controlled according to a temperature detected by the temperature sensor. 5. . The upper surface opposite to the mounting surface of the temperature sensor on the flexible circuit board is placed on the substrate surface located in a region of a side different from the side of the transparent substrate in the liquid crystal panel on which the flexible circuit board is fixedly arranged. The liquid crystal lens according to claim 4, wherein the liquid crystal lens is fixed.

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