JP4989949B2 - Liquid crystal optical element and liquid crystal optical module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal optical element capable of forming an annular electrode in its complete shape without using a through hole, and a liquid crystal optical module. <P>SOLUTION: The liquid crystal optical element (100) has a liquid crystal (130) sandwiched between first and second substrates, a transparent electrode pattern having a plurality of arcuate electrodes (301 to 327) and a plurality of lead-out wiring lines (351 to 377) for supplying voltages to the plurality of arcuate electrodes respectively, a transparent insulating film (170) provided covering the plurality of lead-out wiring lines, and a plurality of complementary electrodes (501 to 527 and 551 to 577) which are disposed straddling the transparent insulating film to be connected to the plurality of arcuate electrodes respectively and form a plurality of rings in complete shapes for changing the refractive indexes to incident light to different extents respectively. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a liquid crystal optical element that functions as a variable focus lens and a liquid crystal optical module having such a liquid crystal optical element.

  A liquid crystal is sandwiched between a common electrode and a plurality of concentric ring-shaped transparent electrode bands, and a voltage applied to the plurality of concentric ring-shaped transparent electrode bands is controlled to form a refractive index distribution of the liquid crystal with respect to the incident light. A variable focus lens using a liquid crystal that forms a phase distribution for obtaining a focal length is known (for example, see Patent Document 1).

  In the variable focus lens described in Patent Document 1, the concentric ring-shaped transparent electrode bands are insulated from each other by an insulator, and a lead-out wiring for supplying a voltage to each concentric ring-shaped transparent electrode band includes a concentric ring. It was arranged from the shape part toward the outside.

  When such a variable focus lens is driven, a predetermined voltage is applied not only to the concentric ring-shaped part but also to the lead-out wiring part. Therefore, the liquid crystal corresponding to the lead-out wiring portion also operates in the same manner as the concentric ring-shaped portion (that is, the liquid crystal corresponding to the lead-out wiring portion changes so as to have a predetermined refractive index), and the ring-shaped refraction The refractive index distribution is not accurately formed, and a refractive index distribution is formed by a plurality of lead wires. The refractive index distribution by a plurality of lead wires is formed like a groove that divides the ring-shaped refractive index distribution, so that light passing through that portion is refracted, and a variable focus lens using such a liquid crystal There is a problem in that an image in which the periphery of a bright spot is blurred or an image in which a bright line is generated is obtained.

  There is also known a variable focus lens in which a plurality of ring-shaped electrodes and lead wires to the plurality of ring-shaped electrodes are formed in different planes, and the plurality of ring-shaped electrodes and the lead wires are connected by through holes ( For example, Patent Document 2).

  In the focusable lens described in Patent Document 2, since there is no omission in the ring-shaped electrode, it is possible to form a lens having good imaging characteristics. However, a plurality of ring-shaped electrodes and lead wires are connected by through holes. Alignment for connection is difficult, and in particular, when a minute and a plurality of annular electrodes are formed, there is a problem that the manufacturing process becomes complicated.

JP 2000-81600 A (FIG. 11) Japanese Patent Laid-Open No. 5-100201 (FIG. 1 (b))

  Therefore, an object of the present invention is to provide a liquid crystal optical element and a liquid crystal optical module that can solve the above problems.

  It is another object of the present invention to provide a liquid crystal optical element and a liquid crystal optical module that do not cause problems due to the lead-out wiring region.

  Furthermore, an object of the present invention is to provide a liquid crystal optical element and a liquid crystal optical module capable of forming a ring-shaped electrode having no omission without using a through hole.

  In order to solve the above problems, a liquid crystal optical element according to the present invention includes a first substrate, a second substrate, a liquid crystal sandwiched between the first and second substrates, and the first or second substrate. A plurality of arc-shaped electrodes formed on one side of the substrate, a plurality of lead wires for supplying a voltage to each of the plurality of arc-shaped electrodes, a transparent insulating film provided so as to cover the plurality of lead wires, and transparent A plurality of complementary electrodes that are arranged so as to straddle the insulating film and are connected to each of the plurality of arc-shaped electrodes, and form a plurality of ring zones without missing portions to change the refractive index for incident light to different degrees. It is characterized by having.

  In order to solve the above problems, a liquid crystal optical element according to the present invention includes a first substrate, a second substrate, a liquid crystal sandwiched between the first and second substrates, and the first or second substrate. A plurality of lead wires formed on one of the two substrates, a transparent insulating film provided so as to cover a part of the plurality of lead wires, and formed on the transparent insulating film and covered with the transparent insulating film It has a plurality of ring-shaped electrodes that are respectively connected to the plurality of lead-out wirings that are not present and change the refractive index for incident light to different degrees.

Furthermore, in order to solve the above-mentioned problem, a liquid crystal optical module according to the present invention includes:
A first substrate; a second substrate; a liquid crystal sandwiched between the first and second substrates; a plurality of arc-shaped electrodes formed on one of the first or second substrate; and the plurality of circles A plurality of lead wires for supplying a voltage to each of the arc-shaped electrodes, a transparent insulating film provided so as to cover the plurality of lead wires, and the plurality of arc-shaped electrodes arranged so as to straddle the transparent insulating film A liquid crystal optical element having a plurality of complementary electrodes that are connected to each other and form a plurality of ring zones without omission to change the refractive index of the incident light to different degrees, and
It has a condensing lens.

Furthermore, in order to solve the above-mentioned problem, a liquid crystal optical module according to the present invention includes:
A first substrate, a second substrate, a liquid crystal sandwiched between the first and second substrates, a plurality of lead wires formed on one of the first or second substrates, and the plurality of lead wires. A transparent insulating film provided so as to cover a part thereof, and each of the plurality of lead wirings formed on the transparent insulating film and not covered by the transparent insulating film; A liquid crystal optical element having a plurality of ring-shaped electrodes for changing to different degrees,
It has a condensing lens.

  According to the present invention, the transparent insulating film prevents the plurality of lead wires from driving the liquid crystal, and the refractive index distribution can be generated by the ring zone or the ring-shaped electrode having no omission. It is possible to solve the problem that an image in which the periphery of a bright spot is blurred or an image in which a bright line is generated is obtained by refraction of light incident on the liquid crystal portion.

  Hereinafter, a liquid crystal optical element and a liquid crystal optical module according to the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a liquid crystal optical element 100 that functions as a variable focus lens.

  A direction indicated by an arrow A in the drawing indicates a direction in which light enters the liquid crystal optical element 100. The liquid crystal optical element 100 is composed of a first liquid crystal layer 130 and a second liquid crystal layer 132 sandwiched between three transparent substrates 101, 102 and 103. The alignment directions of the liquid crystal molecules of the first liquid crystal layer 130 and the second liquid crystal layer 132 are configured to be orthogonal to each other, and the first liquid crystal layer 130 functions as a P-wave liquid crystal lens, The liquid crystal layer 132 functions as an S-wave liquid crystal lens. Note that each element shown in FIG. 1 is exaggerated for convenience of explanation, and is different from an actual thickness ratio.

  In FIG. 1, a transparent counter electrode 110 is formed on a transparent substrate 101 on the incident side. Further, on the transparent substrate 102 facing the transparent substrate 101, a transparent electrode pattern 114 having an arc-shaped electrode pattern 300 and lead wires 351 to 377 described later, a transparent insulating film 170, and a complementary electrode pattern 180 are formed. The first liquid crystal layer 130 is sealed with a thickness a2 (20 μm) between the two transparent substrates 101 and 102 and the seal member 120.

  A transparent counter electrode 118 is formed on the transparent substrate 103 opposite to the incident side. On the transparent substrate 102 facing the transparent substrate 103, a plurality of arc-shaped electrode patterns 700, a transparent electrode pattern 115 having a lead-out wiring region 141, a transparent insulating film 171 and a complementary electrode pattern 181 are formed. The second liquid crystal layer 132 is sealed with a thickness a4 (20 μm) between the two transparent substrates 103 and 102 and the seal member 121.

  The three transparent substrates 101, 102, and 103 are made of a glass material having a refractive index of 1.52, and are formed with thicknesses a1 (130 μm), a3 (300 μm), and a5 (130 μm), respectively. Seal members 120 and 121 are made of resin. In the present embodiment, homogeneous liquid crystal is used as the first and second liquid crystal layers 130 and 132 sandwiched between the three transparent substrates 101, 102, and 103, and the refractive index thereof is 1.50. Vary between ˜1.76. Note that a vertical alignment type liquid crystal may be used as the liquid crystal.

  Incidentally, since the transparent electrode pattern 114 includes the lead-out wiring region 140, the first liquid crystal layer 130 includes the lead-out wiring influence region 131 driven by the lead-out wiring region 140. Similarly, since the transparent electrode pattern 115 includes the lead wiring region 141, the second liquid crystal layer 132 includes the lead wiring influence region 133 driven by the lead wiring region 141. The arc-shaped electrode patterns 300 and 700 have the same shape, and the complementary electrode patterns 180 and 181 have the same shape. An alignment film (not shown) is formed between the layers formed on the transparent substrates 101, 102, and 103 and the first and second liquid crystal layers 130 and 131. Further, the refractive index, thickness, and the like of each component of the liquid crystal optical element 100 are appropriately changed according to the specifications of the liquid crystal optical element 100 and the liquid crystal optical module in which the liquid crystal optical element is disposed.

  FIG. 2 is a diagram illustrating an example of a complementary electrode pattern.

  The complementary electrode pattern 180 shown in FIG. 2 has concentric ring-shaped electrodes 501 to 527 that are not missing, and are arranged with a small interval for insulation. Further, each of the ring-shaped electrodes 501 to 527 is driven by power supplied from the power source 160 via the lead wires 351 to 377 and the arc-shaped electrodes 301 to 327 of the arc-shaped electrode pattern 300 as will be described later. A predetermined AC voltage is individually applied from the IC circuit 150.

  2 corresponds to the cross-sectional view of the liquid crystal optical element 100 in FIG. Further, a position where a transparent insulating film 170 described later is disposed is indicated by a dotted line in the drawing.

  FIG. 3 is a diagram illustrating an example of a plurality of arc-shaped electrodes and a plurality of lead wires.

  The arc-shaped electrode pattern 300 shown in FIG. 3 is formed on the transparent electrode pattern 114, and has concentric arc-shaped electrodes 301 to 327, which are arranged at a minute interval for insulation. Yes. Further, as will be described later, a predetermined AC voltage is individually applied to each of the arc-shaped electrodes 301 to 327 from the drive IC circuit 150 that is supplied with power from the power supply 160 via the lead wires 351 to 377. It is configured as follows.

  FIG. 4 is an enlarged view of the area 330 portion of FIG.

  As shown in FIG. 4, the arc-shaped electrode pattern 300 is connected to lead-out wirings 351 to 377 for supplying voltages to the arc-shaped electrodes 301 to 327, respectively, and lead-out wirings 351 to 377 are arranged. A region (shown by hatching in the drawing) corresponds to the lead-out wiring region 140. The lead wires 351 to 377 are also insulated from each other across a minute region, similarly to the arc-shaped electrodes 301 to 327.

  Since the arc-shaped electrodes 301 to 327 have a plurality of lead wires 351 to 377 arranged on the same plane, the arc-shaped electrodes 301 to 327 are missing and do not become complete ring zones (except for the arc-shaped electrode 301). Further, when a voltage is supplied to the arc-shaped electrodes 301 to 327 via the lead wirings 351 to 377, the above-described problems occur due to the liquid crystal driven by the lead wiring part. Therefore, in the liquid crystal optical element 100 according to the present invention, the transparent insulating film 170 is disposed between the lead-out wiring and the first liquid crystal layer 130 so as to cover the lead-out wirings 351 to 377, and the lead-out wirings 351 to 377. Thus, the first liquid crystal layer 130 is not driven (that is, the lead wiring influence region 131 is not driven). Further, the complementary electrode pattern 180 is formed between the transparent insulating film 170 and the first liquid crystal layer 130, and the ring-shaped electrodes 501 to 527 of the complementary electrode pattern 180 are respectively arc-shaped electrodes of the arc-shaped electrode pattern 300. It was comprised so that it might be connected with 301-327. Accordingly, individual voltages can be supplied to the ring-shaped electrodes 501 to 527 of the complementary electrode pattern 180 via the lead wires 351 to 377 and the arc-shaped electrodes 301 to 327, respectively. Therefore, the ring-shaped electrodes 501 to 527 (see FIG. 2) of the complementary electrode pattern 180 having no omission are ideal as an electrode pattern for refractive index correction, and a refractive index distribution without distortion can be formed.

  Hereinafter, the manufacturing method of the electrode pattern for refractive index correction shown in FIG. 2 will be described with reference to FIGS.

  First, as shown in FIG. 5, the transparent electrode pattern 114 having the arc-shaped electrodes 301 to 327 and the lead wirings 351 to 357 of the arc-shaped electrode pattern 300 is formed on the transparent substrate 102. FIG. 5A shows a plan view of the electrode pattern, and FIG. 5B shows a DD ′ cross-sectional view of FIG. 5A. 5A and 5B show only the arc-shaped electrodes 301 to 304 in the arc-shaped electrode pattern 300 and only the lead wires 351 to 354.

The arc-shaped electrodes 301 to 327 and the lead-out wirings 351 to 377 of the arc-shaped electrode pattern 300 are formed by simultaneously forming a film on the transparent substrate 102 and then using a photolithography method. In addition to ITO, SnO ₂ , ZnO or the like can be used as the transparent electrode member.

  Next, after forming the arc-shaped electrodes 301 to 327 and the lead wires 351 to 357 of the arc-shaped electrode pattern 300, as shown in FIG. 6, a transparent insulating film 170 is formed so as to cover the lead wires 351 to 377. To do. 6A shows a plan view of the electrode pattern, and FIG. 6B shows a DD ′ cross-sectional view of FIG. 6A.

  The transparent insulating film 170 is formed by patterning using a photolithographic method after forming a transparent insulating film on the upper surfaces of the arc-shaped electrodes 301 to 327 and the lead wires 351 to 377 of the arc-shaped electrode pattern 300 formed. Formed. However, the transparent insulating film 170 may be formed by printing. As a material for the transparent insulating film, an acrylic or polyimide photosensitive resin can be used.

  Finally, after the formation of the transparent insulating film 170, as shown in FIG. 7, the ring-shaped electrodes 501 to 527 of the complementary electrode pattern 180 are formed so as to cover the arc-shaped electrodes 301 to 327 of the arc-shaped electrode pattern 300. To do. FIG. 7A shows a plan view of the electrode pattern, and FIG. 7B shows a DD ′ sectional view of FIG. 7A.

Each of the ring-shaped electrodes 501 to 527 of the complementary electrode pattern 180 is obtained by forming a ITO film on the entire surface of the arc-shaped electrode pattern 300 and the transparent insulating film 170 and then patterning it using a photolithography method. In addition to ITO, SnO ₂ , ZnO or the like can be used as the transparent electrode member.

  In the above description, the electrode pattern (shape, configuration, and manufacturing method) including the arc-shaped electrode pattern 300, the lead wires 351 to 377, and the complementary electrode pattern 180 on the transparent substrate 102 corresponding to the first liquid crystal layer 130 has been described. The electrode pattern including the arc-shaped electrode pattern 700 on the transparent substrate 102 corresponding to the second liquid crystal layer 132, the lead-out wiring for supplying a voltage to each arc-shaped electrode of the arc-shaped electrode pattern 700, and the complementary electrode pattern 181. The same applies to (shape, configuration and manufacturing method).

  FIG. 8 is a diagram showing the relationship between each of the annular electrodes 501 to 527 and the voltage applied to them.

  FIG. 8A is an enlarged view of a part of the cross section of the complementary electrode pattern 180 on the transparent substrate 102. All the minute intervals between the ring-shaped electrodes were set to 3 μm (for the sake of convenience, they are shown enlarged, and the description of the arc-shaped electrodes and the transparent insulating film is omitted).

  FIG. 8B shows effective voltages 401 to 427 of the respective ring-shaped electrodes 501 to 527 with respect to a reference voltage (voltage applied to the ring-shaped electrode 527, here 0 [V]). In addition, the liquid crystal used for the liquid crystal optical element generally shows an effective value response to the applied voltage. If a DC voltage component is applied to the liquid crystal for a long time, problems such as burn-in and decomposition of the liquid crystal occur. Accordingly, the liquid crystal is driven by applying an AC voltage to each transparent electrode of the liquid crystal optical element so as not to apply a DC voltage component. Further, the reference voltage 0 [V] for the liquid crystal optical element is precisely a voltage applied to the liquid crystal layer, and the voltage can be arbitrarily set. In general, the applied voltage is often set to 0 [V] as a reference, but it is also possible to set the reference voltage at another voltage value (for example, 3 [V]).

  FIG. 9 is a diagram showing the relationship between the applied voltage and the refractive index of the liquid crystal constituting the first and second liquid crystal layers 130 and 132 used in the present embodiment.

As shown in FIG. 9, the homogeneous liquid crystal using the P-type liquid crystal has a non-linear characteristic in which the refractive index gradually decreases as the applied voltage increases. In the present embodiment, V ₂ is applied to the annular electrode 527 (as a reference voltage) and V ₁ is applied to the annular electrode 501 with respect to the complementary electrode pattern 180. Further, V ₂ (reference voltage) was applied to the transparent counter electrode 110.

By the way, as shown in FIG. 9, in the relationship between the applied voltage and the refractive index of the homogeneous liquid crystal, there is a region that changes almost linearly in the middle (applied voltage range V _{3 to} V ₄ ). Is preferably used as a region for controlling the refractive index. However, in order to obtain a wide operating range, it may be preferable to use a non-linear region.

  FIG. 10 is a diagram illustrating an example of a refractive index distribution pattern formed by the complementary electrode pattern 180.

  In FIG. 10, the vertical axis represents the refractive index of the first liquid crystal layer 130, and the horizontal axis represents the pupil position (X) of the complementary electrode pattern 180. Further, on the X axis, cross sections of the respective ring-shaped electrodes 501 to 527 are shown.

As shown in FIG. 8, an effective voltage 401 (V ₁ ) is applied to the ring-shaped electrode 501 via the lead-out wiring 351 and the arc-shaped electrode 301, so that the ring-shaped electrode 501 and the transparent counter electrode 110 are connected. The refractive index of the first liquid crystal layer 130 sandwiched between the layers is N ₁ (N = 1.78). Similarly, by applying effective voltages 402 to 426 to the ring-shaped electrodes 502 to 526 via the lead wires 352 to 376 and the arc-shaped electrodes 302 to 326, the ring-shaped electrodes 502 to 526 and the transparent counter electrode 110 are applied. The refractive index of the first liquid crystal layer 130 sandwiched between N _{2 and} N ₂₆ is N _{2 to} N ₂₆ . Further, the effective voltage 427 (V ₂ ) is applied to the ring-shaped electrode 527 via the lead-out wiring 377 and the arc-shaped electrode 327, whereby the first electrode sandwiched between the ring-shaped electrode 527 and the transparent counter electrode 110. The refractive index of one liquid crystal layer 130 is N ₂₇ (N = 1.50).

  In this way, by applying a predetermined voltage to each of the annular electrodes 501 to 527, the first liquid crystal layer 130 has a refractive index distribution as shown by the curve 600 in FIG. The liquid crystal optical element 100 having 130 functions as a P-wave variable focus liquid crystal lens (convex lens). As described above, since the complementary electrode pattern 181 has the same shape as the complementary electrode pattern 180 shown in FIG. 2, the same voltage as the voltage applied to the complementary electrode pattern 180 is applied to each complementary electrode pattern 181. By applying to the annular zone, the second liquid crystal layer 132 also has a refractive index distribution as shown by a curve 600 in FIG. Therefore, the liquid crystal optical element 100 having the second liquid crystal layer 132 also functions as a variable focus liquid crystal lens (convex lens) for S waves.

  11 is a cross-sectional view of the liquid crystal optical module 1 according to the present invention, and FIG. 12 is an exploded perspective view of the liquid crystal optical module 1 shown in FIG.

  The liquid crystal optical module 1 includes the above-described liquid crystal optical element 100 for changing the focus, three first to third optical lenses L1 to L3 housed in the lens frame 30, and an optical image formed as an image. The photoelectric conversion element 50 for converting the signal into an electric signal is disposed in the case 10 and the base 60 as a main component. Light from the subject incident from the case opening 11 of the case 10 passes through the liquid crystal optical element 100 and the first to third optical lenses L1 to L3, forms an image on the photoelectric conversion element 50, and is converted into an electrical signal. The In the present embodiment, the case 10 is configured as a rectangular box corresponding to the outer shape of the liquid crystal optical element 100 as shown in FIG. 12, but is not limited to a rectangular shape. The outer shape of the module is a cube of about 6 mm.

  The surface of the liquid crystal optical element 100 facing the first optical lens L1 is placed on the annular protrusion 31 protruding from the front surface of the lens frame 30, and the surface of the liquid crystal optical element 100 facing the case 10 is the case opening. It is pressed against the case 10 via an annular elastic member 15 having a diameter larger than 11. The liquid crystal optical element 100 is pressed and fixed by an annular elastic member 15 that is a first pressing member and an annular protrusion 31 that is a second pressing member. Since the annular protrusion 31 and the annular elastic member 15 press the seal members 120 and 121 of the liquid crystal optical element 100, the gap thickness of the liquid crystal optical element 100 is not changed by the pressing force. Therefore, the optical characteristics are not deteriorated due to the fluctuation of the gap thickness of the liquid crystal due to the pressing force. The annular elastic member 15 is desirably bonded to the liquid crystal optical element 100 and the case 10 with an adhesive. Also, it is better to bond the annular protrusion 31 and the liquid crystal optical element 100 together.

  In the liquid crystal lens module in which the focal point changes as the conventional lens frame moves in the optical axis direction, the case opening 11 needs a protective glass (cover glass) to prevent intrusion of dust and the like. However, in this embodiment using the liquid crystal optical element 100, the transparent substrate of the liquid crystal optical element 100 is in close contact with the case opening 11 because the transparent substrate of the liquid crystal optical element 100 is in close contact with the annular elastic member 15. The protective glass is also used, and the protective glass of the case opening 11 is omitted. In some cases, a protective glass with a case opening can be attached.

  Inside the cylindrical lens frame 30, three first to third optical lenses L1 to L3 are housed. The first optical lens L1 is disposed to face the opening 32 on the subject side end surface of the lens frame 30, the second optical lens L2 is disposed below the first optical lens L1, and a disc-like spacer 33 having an opening is further interposed therebetween. The third optical lens L3 is disposed. As a method for arranging these optical lenses in the lens frame, a known method can be adopted as appropriate.

  The disc-like spacer 33 disposed between the second optical lens L2 and the third optical lens L3 is for adjusting the lens interval, and may not be necessary in other embodiments. In addition, the disc-like spacer 33 for adjusting the lens interval is provided between the first optical lens L1 and the second optical lens L2, or between the liquid crystal optical element 100 and the first optical lens L1. Can also be placed if necessary. In the present embodiment, since the first optical lens L1 is sequentially inserted and fixed to the lens frame 30, the disk-shaped spacer 33 is used. However, in other embodiments, the disk-shaped spacer 33 is used. Instead of this, a flange that protrudes into the lens frame 30 may be used. Further, the number of optical lenses to be arranged is not limited to three, and at least one is sufficient.

  The lens frame 30 is fixed to the lens frame holder 40 supported by the base 60, and a protrusion 41 provided on the outer periphery of the lens frame holder 40 engages with the engaging portion 12 of the case 10, thereby The third optical lenses L1 to L3 and the liquid crystal optical element 100 are fixedly disposed on the case 10. Although the lens frame holder 40 may be configured integrally with the lens frame 30, it is preferable that the lens frame 30 is movable with respect to the lens frame holder 40 as a separate body as shown in the figure. Thus, the distance between the optical lens and the photoelectric conversion element 50 can be adjusted by final assembly of the lens frame 30 and the lens frame holder 40. In this case, the annular elastic member 15 interposed between the liquid crystal optical element 100 and the case 10 serves to absorb a change in the distance between the liquid crystal optical element 100 and the case 10 due to the movement of the lens frame 30 in the optical axis direction. The height from the bottom surface of the base 60 to the upper surface of the lens frame 30 can always be kept constant.

  The photoelectric conversion element 50 for converting an image formed by the optical system into an electric signal is formed by a CCD or a CMOS, and the light receiving surface of the photoelectric conversion element 50 is exposed from the opening of the printed circuit board 51. Provided on the back side. On the surface of the printed circuit board 51, an infrared (IR) cut filter 52 is disposed to cover the opening of the printed circuit board 51 and prevent infrared light from entering the photoelectric conversion element 50. The infrared cut filter 52 needs to have a distance between the infrared cut filter 52 and the photoelectric conversion element 50 so that dust or the like attached to the infrared cut filter 52 does not appear in the photoelectric conversion element 50. For this purpose, the infrared cut filter 52 is provided at a predetermined distance from the photoelectric conversion element 50 via the filter mounting frame 53. A lead electrode (not shown) is formed on the printed circuit board 51, and an image signal taken out by the lead electrode is sent to a digital signal processing unit.

  In this embodiment, between the lens frame 30 holding the first to third optical lenses L1 to L3 and the case 10, the liquid crystal optical element 100 is connected to the annular elastic member 15 which is the first pressing member and the first elastic member 15. 2 is pressed and held by the annular projecting portion 31 which is a pressing member, a holder for holding the liquid crystal optical element 100 is not required, and a compact liquid crystal lens module can be formed. The positions of the first to third optical lenses L1 to L3 in the optical axis direction are easily determined.

  Here, the maximum incident angle θ to the liquid crystal optical element 100 is determined by the opening of the case 10 and the opening 32 on the subject side end face of the lens frame 30, and the value thereof is 30 degrees.

  FIG. 13 shows an application example of the liquid crystal optical module 1 using the liquid crystal optical element 100 according to the present invention.

  In FIG. 13, a lens L indicates a lens group including the first to third optical lenses L1 to L3 described in FIGS. 11 and 12, and C indicates a control unit including a CPU and a power source.

  FIG. 13A shows a case where the focus is set to infinity, and since the reference voltage is applied to the complementary electrode patterns 180 and 181 of the liquid crystal optical element 100, the liquid crystal optical element 100 does not have power, and the liquid crystal Incident light having an effective diameter 10 incident on the optical module 1 is condensed on the photoelectric conversion element 50 only by the lens L.

  FIG. 13B shows a case where the focus is adjusted to a short distance, and by applying a predetermined voltage to the complementary electrode patterns 180 and 181 of the liquid crystal optical element 100, the liquid crystal optical element 100 is shown in FIG. It functions as a convex lens having a curve 600 of the refractive index distribution shown. Accordingly, the incident light incident on the liquid crystal optical module 1 has a focal length different from the focal length of only the lens L (see 7 in the figure) by the liquid crystal optical element 100 and the lens L, as shown in 6 in the figure. It is condensed on the photoelectric conversion element 50.

  Further, if the voltage value applied to the complementary electrode pattern 180 of the liquid crystal optical element 100 is varied in accordance with a signal from a predetermined autofocus adjustment circuit, an autofocus optical system can be easily configured without using moving parts. Is possible. If the liquid crystal optical module 1 capable of switching the focal length without using such moving parts is used for a digital camera or a mobile phone, there is a great advantage that space and cost can be reduced.

  FIG. 14 is a diagram showing another example of the electrode pattern of the liquid crystal optical element 100 described above. 14A shows a plan view of the electrode pattern, and FIG. 14B shows a DD ′ cross-sectional view in FIG. 14A.

  In FIG. 7, the ring-shaped electrodes 501 to 527 of the complementary electrode pattern 180 are again formed on the arc-shaped electrodes 301 to 327 of the arc-shaped electrode pattern 300. However, since the arc-shaped electrodes 301 to 327 have already been formed in most areas other than the lead-out wiring area 140, it is not always necessary to form the ring-shaped electrodes 501 to 527 again.

  Therefore, in the example of FIG. 14, the fan-shaped electrodes 552 to 577 of the complementary electrode pattern 182 are formed so as to straddle the transparent insulating film 170 formed so as to cover the lead-out wiring region 140. In FIG. 14, only the arc-shaped electrodes 301 to 304 in the arc-shaped electrode pattern 300 and only the fan-shaped electrodes 552 to 554 in the complementary electrode pattern 182 are shown. As shown in FIG. 14, the fan-shaped electrode 552 is arranged so as to be connected to one end and the other end of the arc-shaped electrode 302 so as to connect the portions covered by the transparent insulating film 170. . In addition, the fan-shaped electrode 552 has the same potential as the arc-shaped electrode 302 through the lead wiring 352. Therefore, the arc-shaped electrode 302 and the fan-shaped electrode 552 form a ring-shaped electrode having the same potential and having no gap.

  Similarly, the fan-shaped electrodes 553 to 577 are arranged so as to be connected to one end and the other end of the arc-shaped electrodes 303 to 327 so as to connect the portions covered by the transparent insulating film 170, respectively. The Further, the fan-shaped electrodes 553 to 577 have the same potential as the arc-shaped electrodes 303 to 327 through the lead wires 353 to 377, respectively. Therefore, the arc-shaped electrodes 303 to 327 and the fan-shaped electrodes 553 to 527 form a plurality of ring-shaped electrodes having the same potential and having no missing portions.

The fan-shaped electrodes 552 to 527 shown in FIG. 14 are formed by forming a transparent insulating film 170, forming ITO on the arc-shaped electrodes 301 to 327 of the arc-shaped electrode pattern 300 and the transparent insulating film 170, and then performing photolithography. It is a pattern that uses. In addition to ITO, SnO ₂ , ZnO or the like can be used as the transparent electrode member. Here, the arc-shaped electrode pattern 300 and the lead wires 351 to 377 and the transparent insulating film 170 are formed by a method similar to the method shown in FIGS.

  Even if the annular electrodes 501 to 527 of the complementary electrode pattern 180 as shown in FIG. 7 are not formed, the fan-shaped electrodes 552 to 577 are formed so as to straddle the transparent insulating film 170 as shown in FIG. However, the same effect can be obtained. Note that the size of the fan-shaped electrodes 552 to 577 is not limited to that shown in FIG. 14, and an optimal design value can be used as appropriate.

  FIG. 15 is a diagram showing still another example of the electrode pattern of the liquid crystal optical element 100 described above. 15A shows a plan view of the electrode pattern, and FIG. 15B shows a DD ′ cross-sectional view in FIG. 15A.

  In the example shown in FIG. 14, after forming the arc-shaped electrode pattern 300 and the lead wires 351 to 377, the transparent insulating film 170 is formed, and then the complementary electrode pattern 180 is formed so as to straddle the transparent insulating film 170. . On the other hand, in the example shown in FIG. 15, the lead wirings 801 to 827 are formed first, and then the transparent insulating film 172 is formed so as to cover other parts while leaving a part of the lead wirings 801 to 827. Thereafter, each of the ring-shaped electrodes 901 to 927 of the transparent electrode pattern 900 is formed. Each of the ring-shaped electrodes 901 to 927 of the transparent electrode pattern 900 has the same shape as the ring-shaped electrodes 501 to 527 of the complementary electrode pattern 180 shown in FIG. In FIG. 15, only the ring-shaped electrodes 901 to 904 in the transparent electrode pattern 900 are shown.

  Therefore, an appropriate voltage can be supplied to each of the ring-shaped electrodes 901 to 927 of the transparent electrode pattern 900 via the lead wiring electrodes 801 to 827 formed first, and each of the ring-shaped electrodes of the transparent electrode pattern 900 can be supplied. It is possible to prevent the electrodes 901 to 927 from being missing.

  A method for manufacturing the electrode pattern shown in FIG. 15 will be described below with reference to FIGS.

  FIG. 16 is a diagram showing the lead wiring formed first. FIG. 16A shows a plan view of the electrode pattern, and FIG. 16B shows a DD ′ cross-sectional view in FIG.

FIG. 16 shows only the lead wires 801 to 804 among the lead wires 801 to 827. The lead wires 801 to 827 are formed by forming a film of ITO on the transparent substrate 102 and then patterning it using a photolithography method. In addition to ITO, SnO ₂ , ZnO, or the like can be used as a material for the lead wiring.

  FIG. 17 is a diagram illustrating an example of a transparent insulating film formed on the lead-out wiring. FIG. 17A shows a plan view of the electrode pattern, and FIG. 17B shows a DD ′ cross-sectional view in FIG.

  As shown in FIG. 17, the transparent insulating film 172 has a shape that covers only other portions of the lead-out wirings 801 to 827 and covers other portions. In each lead-out wiring 801 to 827, a portion that is not covered with the transparent insulating film 172 is a portion that is connected to each of the ring-shaped electrodes 901 to 927 of the transparent electrode pattern 900 to be formed later. The transparent insulating film 172 is formed by forming a transparent insulating film on the entire upper surface of the formed lead wirings 801 to 827 and then patterning it using a photolithography method. However, the transparent insulating film 172 may be formed by printing. As a material for the transparent insulating film, an acrylic or polyimide photosensitive resin can be used.

  After forming the transparent insulating film 172 shown in FIG. 17, the ring-shaped electrodes 901 to 927 of the transparent electrode pattern 900 are formed thereon, thereby forming the electrode pattern shown in FIG. 15. The ring-shaped electrodes 901 to 927 of the transparent electrode pattern 900 are manufactured by the same method as that of the complementary electrode pattern 180 described above.

  FIG. 18 is a view showing a modification of the lead wiring shown in FIG.

  In the example shown in FIG. 15, the lead wires 801 to 827 are covered with the transparent insulating film 172 so as to leave a part of the tips of the lead wires 801 to 827. However, as shown in FIG. 18, protrusions 852 to 877 for better connection with the respective ring-shaped electrodes 901 to 927 of the transparent electrode pattern 900 to be formed later on the leading ends of the lead wirings 801 to 827. (In FIG. 8, only the protrusions 852 to 854 are shown). The protrusions 852 to 877 shown in FIG. 18 are particularly effective when the ring-shaped electrodes 901 to 927 of the transparent electrode pattern 900 are extremely thin and a sufficient area of the connection portion cannot be secured. Further, by providing the protrusions 852 to 877, the shape of the transparent insulating film can be made simple as shown in FIG. 18 instead of a complicated shape as shown in FIG. .

  The procedure for forming the ring-shaped electrodes 901 to 927 of the transparent insulating film 170 and the transparent electrode pattern 900 after forming the lead wires 801 to 827 and the protruding portions 852 to 877 as shown in FIG. To As described in FIG.

1 is a cross-sectional view of a liquid crystal optical element 100 according to the present invention. It is a figure which shows an example of a complementary electrode pattern. It is a figure which shows an example of an arc-shaped electrode pattern. FIG. 4 is a partially enlarged view of FIG. 3. It is a figure for demonstrating the manufacturing method of the transparent electrode pattern shown in FIG. It is a figure for demonstrating the manufacturing method of the transparent electrode pattern shown in FIG. It is a figure for demonstrating the manufacturing method of the transparent electrode pattern shown in FIG. (A) is the elements on larger scale of the cross section of a transparent electrode pattern, (b) is the figure which showed the example of the applied voltage to each ring-shaped electrode. It is a figure which shows the relationship between the applied voltage and refractive index of a liquid crystal. It is a figure which shows an example of the refractive index distribution pattern formed of a transparent electrode pattern. It is sectional drawing of the liquid crystal optical module which concerns on this invention. It is a disassembled perspective view of the liquid crystal optical module shown in FIG. It is the figure which showed the usage example of the liquid crystal optical module which concerns on this invention. It is a figure which shows the other example of the transparent electrode pattern for refractive index correction | amendment. It is a figure which shows the further another example of the transparent electrode pattern for refractive index correction | amendment. It is a figure for demonstrating the manufacturing method of the transparent electrode pattern shown in FIG. It is a figure for demonstrating the manufacturing method of the transparent electrode pattern shown in FIG. It is a figure which shows the modification of extraction wiring.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Liquid crystal optical element 101,102,103 Transparent substrate 130 1st liquid crystal layer 132 2nd liquid crystal layer 170,171,172 Transparent insulating film 180,181,182 Complementary electrode pattern 300 Arc-shaped electrode pattern 301-327 Arc-shaped electrode 351 to 377, 801 to 827 Lead-out wiring 501 to 527, 901 to 927 Ring-shaped electrode 552 to 577 Fan-shaped electrode 852 to 877 Projection

Claims (10)

A liquid crystal optical element that acts as a variable focus lens for incident light,
A first substrate;
A second substrate;
Liquid crystal sandwiched between the first and second substrates;
A plurality of arc-shaped electrodes formed on one of the first or second substrate and a plurality of lead wires for supplying a voltage to each of the plurality of arc-shaped electrodes;
A transparent insulating film provided to cover the plurality of lead wires;
A plurality of annular zones that are arranged so as to straddle the transparent insulating film and are connected to each of the plurality of arc-shaped electrodes and have no omission to change the refractive index with respect to the incident light to different degrees. With complementary electrodes,
A liquid crystal optical element comprising:   The liquid crystal optical element according to claim 1, wherein the plurality of annular zones are configured only by the plurality of complementary electrodes.   2. The liquid crystal optical element according to claim 1, wherein the plurality of annular zones includes the plurality of arc-shaped electrodes and the plurality of complementary electrodes. A liquid crystal optical element that acts as a variable focus lens for incident light,
A first substrate;
A second substrate;
Liquid crystal sandwiched between the first and second substrates;
A plurality of lead wires formed on one of the first or second substrates;
A transparent insulating film provided so as to cover a part of the plurality of lead wires;
A plurality of ring-shaped electrodes connected to the plurality of lead wirings formed on the transparent insulating film and not covered by the transparent insulating film, respectively, for changing the refractive index with respect to the incident light to different degrees. And having
The plurality of lead wires and the plurality of ring-shaped electrodes are disposed on the same surface of the first substrate or the second substrate.
A liquid crystal optical element.   5. The liquid crystal optical element according to claim 4, wherein each of the plurality of lead wirings has a protrusion for connecting to the plurality of annular electrodes. A liquid crystal optical module acting as a variable focus lens,
A first substrate; a second substrate; a liquid crystal sandwiched between the first and second substrates; a plurality of arc-shaped electrodes formed on one of the first or second substrate; and the plurality of circles A plurality of lead wires for supplying a voltage to each of the arc-shaped electrodes, a transparent insulating film provided so as to cover the plurality of lead wires, and the plurality of arc-shaped electrodes arranged so as to straddle the transparent insulating film A liquid crystal optical element having a plurality of complementary electrodes that are connected to each other and that form a plurality of ring zones that are not missing to change the refractive index of the incident light to different degrees;
A condenser lens;
A liquid crystal optical module comprising:   The liquid crystal optical module according to claim 6, wherein the plurality of annular zones are configured by only the plurality of complementary electrodes.   The liquid crystal optical module according to claim 6, wherein the plurality of annular zones are configured by the plurality of arc-shaped electrodes and the plurality of complementary electrodes. A liquid crystal optical module acting as a variable focus lens,
A first substrate, a second substrate, a liquid crystal sandwiched between the first and second substrates, a plurality of lead wires formed on one of the first or second substrates, and the plurality of lead wires. A transparent insulating film provided so as to cover a part thereof, and each of the plurality of lead wirings formed on the transparent insulating film and not covered by the transparent insulating film; Each has a plurality of ring-shaped electrodes for changing to different degrees, and the plurality of lead- out wirings and the plurality of ring-shaped electrodes are arranged on the same surface of the first substrate or the second substrate. A liquid crystal optical element,
A condenser lens;
A liquid crystal optical module comprising:   10. The liquid crystal optical module according to claim 9, wherein each of the plurality of lead wirings has a protrusion for connecting to the plurality of annular electrodes.

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