JP4996114B2 - Aperture optical element for camera and manufacturing method thereof - Google Patents

Description

  The present invention relates to a diaphragm optical element for a camera using a liquid crystal display element or an electrochromic display element, and a method for manufacturing the same.

  Conventionally, there has been known an aperture mechanism that controls the amount of light that strikes the photosensitive portion of a camera to adjust the amount of light and adjust the focus.For example, a mechanism that mechanically expands or contracts the size of the opening is known. is there. However, a diaphragm mechanism that mechanically expands / contracts the size of the opening requires a motor as a drive source, and thus there is a problem that the apparatus cannot be increased in size and that there is vibration. In addition, since the aperture mechanism is a stepwise adjustment, there is a problem that noise occurs at the time of shooting or the brightness changes abruptly at the time of switching, resulting in poor reliability.

  In order to solve the above problems, a diaphragm mechanism has been proposed in which a transmissive liquid crystal panel or electrochromic panel having a transparent electrode layer having a circular opening pattern is electrically controlled to change the opening pattern. (See Patent Document 1).

  In the case of the liquid crystal panel, the diaphragm mechanism is switched depending on the application so that the entire surface of the liquid crystal panel is a quarter wavelength plate or only the opening pattern portion is a quarter wavelength plate. In the case of the electrochromic panel, the entire surface of the electrochromic panel is made transparent or only the opening pattern portion is changed depending on the application.

  Since the diaphragm mechanism electrically controls the liquid crystal panel or the electrochromic panel, the apparatus can be downsized, and the brightness can be continuously adjusted without vibration.

However, the diaphragm mechanism can only be switched in two stages, that is, the entire panel surface or only the circular opening pattern portion, and there is a disadvantage that the focus cannot be adjusted sufficiently.
JP-A-9-106566 (Claims 2, 6, 9)

  The present invention provides a diaphragm optical element for a camera that can eliminate such inconvenience, can continuously adjust the amount of light hitting the photosensitive part of the camera, and can adjust the focus, and a method for manufacturing the same. The purpose is to do.

The present invention includes a pair of a transparent electrode layer having a predetermined pattern and a liquid crystal alignment film layer formed on the transparent electrode layer on one surface, the liquid crystal alignment film layers being arranged to face each other. And a liquid crystal layer including a dichroic dye and a chiral agent. The transparent electrode layer is concentrically formed on the glass substrate. The liquid crystal alignment film layer is provided on each of the plurality of portions of the transparent electrode layer.

  In the diaphragm optical element for a camera having the above-described configuration, in the portion where the transparent electrode layer is formed, the liquid crystal in the liquid crystal layer is determined by the liquid crystal alignment film layer formed on the transparent electrode layer. Is oriented. Therefore, in the diaphragm optical element for a camera, depending on the alignment direction of the liquid crystal, the transmittance or reflectance is maximized in the state where no voltage is applied, and the transmittance or reflectance gradually decreases as the applied voltage increases, or the voltage The transmittance or reflectance is minimized when no voltage is applied, and the transmittance or reflectance gradually increases as the applied voltage increases.

  At this time, since the transparent electrode layer is composed of a plurality of portions arranged concentrically, for example, when the transmittance or reflectance is maximized without applying a voltage, the transparent electrode layer is opened with no voltage applied. The opening portion can be reduced by increasing the portion to which the voltage is applied from the outside to the inside of the plurality of portions having the largest portion and concentrically arranged. On the other hand, when the transmittance or reflectance is minimized when no voltage is applied, the opening is the smallest when no voltage is applied, and from the inside of the plurality of concentrically arranged portions. The opening can be enlarged by increasing the portion to which the voltage is applied outward.

  Therefore, according to the diaphragm optical element for a camera, the size of the opening can be selected depending on which part of the plurality of transparent electrode layers arranged concentrically to which the voltage is applied. Adjustments can be made. Further, according to the diaphragm optical element for a camera, in any of the above cases, the amount of light is adjusted by changing the transmittance or the reflectance by increasing or decreasing the voltage in the portion where the voltage is applied. Can do.

  In the camera aperture optical element, the liquid crystal alignment film may be a vertical alignment film, for example. In this case, since the liquid crystal in the liquid crystal layer is aligned in the direction perpendicular to the glass substrate by the vertical alignment film, the transmittance or reflectance is maximized when no voltage is applied.

According to a second aspect of the present invention, a first glass substrate including a transparent electrode layer having a predetermined pattern on one surface and an electrochromic film layer formed on the transparent electrode layer, and one surface. A second electrode substrate provided with a transparent electrode layer having a predetermined pattern, the transparent electrode layer being disposed opposite the electrochromic film layer of the first glass substrate, and an electrolyte layer disposed between the two glass substrates. The transparent electrode layer includes a plurality of portions arranged concentrically on the glass substrate , and the electrochromic film layer is the transparent electrode layer of the first glass substrate. It is provided on each of the plurality of portions .

  The aperture optical element for a camera having the above configuration is transparent when no voltage is applied, but when a voltage is applied, cations are injected from the electrolyte layer into the electrochromic film layer, and the electrochromic film layer is colored. The coloring gradually increases as the applied voltage increases.

  At this time, since the transparent electrode layer is composed of a plurality of portions arranged concentrically, the opening is maximum when no voltage is applied, and from the outside to the inside of the plurality of portions arranged concentrically. By increasing the portion to which the voltage is applied, the colored portion can be increased and the opening can be reduced.

  Therefore, according to the diaphragm optical element for a camera, the size of the opening can be selected depending on which part of the plurality of transparent electrode layers arranged concentrically to which the voltage is applied. Adjustments can be made. Further, according to the camera aperture optical element, the amount of light can be adjusted by changing the transmittance or the reflectance by increasing or decreasing the voltage in the portion where the voltage is applied.

  In the camera aperture optical element, the electrochromic film layer may be a tungsten trioxide film, for example. In this case, the electrochromic film layer is colored blue when cations are injected from the electrolyte layer by applying a voltage.

The diaphragm optical element for a camera of the present invention includes a step of forming a transparent electrode layer on the entire surface of a pair of glass substrates, and an alignment film layer for liquid crystal on the entire surface of the transparent electrode layer formed on each glass substrate. Forming the transparent electrode layer and the alignment layer for liquid crystal on each glass substrate, and irradiating the surface of the transparent electrode layer and the alignment film layer for liquid crystal with a laser; By removing the film layer, a transparent electrode layer having a plurality of portions arranged concentrically on each glass substrate, and the alignment film layer for liquid crystal are formed on each of the plurality of portions of the transparent electrode layer It can manufacture advantageously by a manufacturing method provided with the process to do.

  In the manufacturing method, first, a transparent electrode layer is formed on the entire surface of a pair of glass substrates by a method known per se, and then a liquid crystal alignment film layer is formed on the entire surface of the transparent electrode layer. Instead of forming a transparent electrode layer on the entire surface of the glass substrate, a commercially available glass substrate having a transparent electrode layer formed on the entire surface may be used.

  Next, a surface of the pair of glass substrates on which the transparent electrode layer and the alignment film layer for liquid crystal are formed is irradiated with laser, and the transparent electrode layer and the alignment for liquid crystal in the portion irradiated with the laser are irradiated. The membrane layer is removed. As a result, according to the said manufacturing method, a transparent electrode layer provided with the some part arrange | positioned concentrically on each glass substrate can be formed accurately.

  At this time, in the manufacturing method, the transparent electrode layer and the alignment film layer for liquid crystal are mainly formed by laser ablation without damaging the glass substrate by appropriately setting the type of laser, irradiation conditions, and the like. It can be decomposed at the atomic level and removed from the glass substrate.

The diaphragm optical element for a camera according to the second aspect of the present invention includes a step of forming a transparent electrode layer on the entire surface of a pair of glass substrates, and an entire surface of the transparent electrode layer formed on the first glass substrate. Forming an electrochromic film layer on the surface, and irradiating a laser on the surface of the first glass substrate on which the transparent electrode layer and the electrochromic film layer are formed, and the transparent portion of the portion irradiated with the laser The electrode layer and the electrochromic film layer are removed, and the surface of the second glass substrate on which the transparent electrode layer is formed is irradiated with a laser to remove the transparent electrode layer in the portion irradiated with the laser. Forming a transparent electrode layer comprising a central circle and a plurality of concentric circles surrounding the center circle on each glass substrate, and on each of the plurality of transparent electrode layers of the first glass substrate The electrochromic film By a production method comprising a step of forming a can be advantageously produced.

  In the manufacturing method, first, a transparent electrode layer is formed on the entire surface of a pair of glass substrates by a method known per se. Further, as in the case of the method of manufacturing the camera aperture optical element of the first aspect, instead of forming a transparent electrode layer on the entire surface of the glass substrate, a commercially available glass having a transparent electrode layer formed on the entire surface. A substrate may be used.

  Next, an electrochromic film layer is formed on the entire surface of the transparent electrode layer formed on the first glass substrate. At this time, the electrochromic film layer is not formed on the transparent electrode layer on the second glass substrate.

  Next, the surface of the first glass substrate on which the transparent electrode layer and the electrochromic film layer are formed is irradiated with a laser, and the transparent electrode layer and the electrochromic film layer in a portion irradiated with the laser And remove. Further, the surface of the second glass substrate on which the transparent electrode layer is formed is irradiated with a laser, and the transparent electrode layer in the portion irradiated with the laser is removed. As a result, according to the said manufacturing method, a transparent electrode layer provided with the some part arrange | positioned concentrically on each glass substrate can be formed accurately.

  At this time, in the manufacturing method, by appropriately setting the type of laser, irradiation conditions, etc., without damaging the glass substrate, the transparent electrode layer and the electrochromic film layer mainly by laser ablation, Alternatively, only the transparent electrode layer can be decomposed at the atomic level and removed from the glass substrate.

  Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is an explanatory sectional view showing an embodiment of a camera diaphragm optical element according to the present invention, FIG. 2 is a plan view showing a pattern shape of a transparent electrode layer in the camera diaphragm optical element shown in FIG. 1, and FIG. 2 is a graph showing spectral characteristics of the camera aperture optical element shown in FIG. FIG. 4 is an explanatory sectional view showing another embodiment of the camera aperture optical element of the present invention, and FIG. 5 is a graph showing the spectral characteristics of the camera aperture optical element shown in FIG.

  As shown in FIG. 1, the camera aperture optical element 1 a according to the first aspect of the present embodiment includes glass substrates 2 and 3 made of transparent plate glass, and a liquid crystal layer 4 disposed between the glass substrates 2 and 3. The liquid crystal layer 4 is sealed with a sealing agent layer 5 formed on the outer edges of the glass substrates 2 and 3. The glass substrate 2 includes transparent electrode layers 6 a, 6 b, 6 c, 6 d on the surface facing the glass substrate 3, and the glass substrate 3 has transparent electrode layers 7 a, 7 b, 7 c, 7d. The transparent electrode layers 6a, 6b, 6c, 6d, 7a, 7b, 7c, and 7d are made of, for example, ITO. A liquid crystal alignment film layer 8 is formed on each of the transparent electrode layers 6a, 6b, 6c, 6d, 7a, 7b, 7c, and 7d.

  As shown in FIG. 2 (a), the transparent electrode layers 6a, 6b, 6c, 6d formed on the glass substrate 2 are centered on a circular transparent electrode layer 6a, and are spaced from each other around the transparent electrode layers 6a, 6b, 6c, 6d. A concentric pattern shape in which doughnut-shaped transparent electrode layers 6b, 6c, and 6d are formed is formed. The transparent electrode layers 6a, 6b, 6c, and 6d have a maximum diameter (corresponding to the outer diameter of the transparent electrode layer 6d) as a practical size in the range of 4 to 10 mm. For example, the ratio of the area of the opening Can be changed in four stages of 100%, 50%, 25%, and 12.5%. Therefore, for example, when the outer diameter of the transparent electrode layer 6d is 6 mm, the outer diameter of the transparent electrode layer 6c is 4.2 mm, the outer diameter of the transparent electrode layer 6b is 3.0 mm, and the diameter of the transparent electrode layer 6a is 2. The interval between the transparent electrode layers 6a, 6b, 6c, and 6d is set to 60 μm. The transparent electrode layers 6a, 6b, 6c and 6d are connected to each other by a connection portion 9 made of the same material as the transparent electrode layers 6a, 6b, 6c and 6d, and are connected to an external power source via the connection portion 9. It can be turned on and off at the same time.

  On the other hand, the transparent electrode layers 7a, 7b, 7c and 7d formed on the glass substrate 3 are spaced from each other around the circular transparent electrode layer 7a as shown in FIG. 2B. Thus, a concentric pattern shape in which donut-shaped transparent electrode layers 7b, 7c, and 7d are formed is formed. The outer diameter of the transparent electrode layers 7d, 7c, 7b is the same as the outer diameter of the transparent electrode layers 6d, 6c, 6b, and the diameter of the transparent electrode layer 7a is the same as the diameter of the transparent electrode layer 6a. The intervals between the transparent electrode layers 7a, 7b, 7c, and 7d are the same as the intervals between the transparent electrode layers 6a, 6b, 6c, and 6d. Each of the transparent electrode layers 7a, 7b, 7c, and 7d is independently connected to an external power source via the connection portions 10a, 10b, 10c, and 10d formed by removing a part of the transparent electrode layers 7b, 7c, and 7d. It can be connected freely and can be turned on / off independently. The connecting portions 10a, 10b, 10c, and 10d are made of the same material as the transparent electrode layers 7a, 7b, 7c, and 7d.

  The liquid crystal alignment film layer 8 may be formed of a vertical alignment film or a horizontal alignment film, but is preferably formed of a vertical alignment film in that high transmittance can be obtained at a low voltage.

  The liquid crystal layer 4 is composed of a liquid crystal containing a dichroic dye and a chiral agent. The dichroic dye is preferably used by mixing at least three kinds of dyes, and usually 3 to 7 kinds of dyes, for example, five kinds of dyes are mixed and used. The chiral agent is preferably added so that d / p is in the range of 0.5-1.

  The camera aperture optical element 1a of this aspect can be manufactured as follows, for example.

  First, a pair of glass substrates 2 and 3 having a transparent electrode layer made of ITO formed on the entire surface are prepared. The glass substrates 2 and 3 are made of transparent blue plate glass having a thickness of 0.7 mm, and the transparent electrode layer is formed to a thickness of 2000 angstroms.

  Next, a vertical alignment film is formed as a liquid crystal alignment film layer on each of the transparent electrode layers of the glass substrates 2 and 3.

  Next, the surface of the glass substrates 2 and 3 on which the transparent electrode layer and the liquid crystal alignment film layer are formed is irradiated with a YVO laser or YAG laser, for example, a YVO laser (manufactured by YVO) having an output of 10 W and a wavelength of 1064 nm. Then, unnecessary portions of the transparent electrode layer and the liquid crystal alignment film layer are removed to form the pattern shapes shown in FIGS. 2 (a) and 2 (b). The laser irradiation is preferably performed by setting the LD power in the range of 1 to 100%, the Q switch in the range of 10 to 100 kHz, and the moving speed in the range of 1 to 1500 mm / sec. The Q switch is 40 kHz and the moving speed is 300 mm / sec.

  As a result, on the glass substrate 2, the transparent electrode layers 6a, 6b, 6c, and 6d, the connection portion 9, the transparent electrode layers 6a, 6b, 6c, and 6d, and the liquid crystal alignment film layer formed on the connection portion 9 are obtained. 8 is obtained. Moreover, on the glass substrate 3, transparent electrode layer 7a, 7b, 7c, 7d, connection part 10a, 10b, 10c, 10d, transparent electrode layer 7a, 7b, 7c, 7d, connection part 10a, 10b, 10c , 10d, the liquid crystal alignment film layer 8 is obtained.

  When the portion irradiated with the laser was observed with a microscope, the transparent electrode layer and the liquid crystal alignment film layer were completely removed, and the surfaces of the glass substrates 2 and 3 were exposed. The surface of the glass substrates 2 and 3 has a surface roughness of about 120 angstroms, but the surface roughness is comparable to the surfaces of the transparent electrode layers 6a, 6b, 6c, 6d, 7a, 7b, 7c and 7d. The surface state of the display substrate is sufficiently smooth.

  The YVO laser is absorbed by ITO forming the transparent electrode layer, but is transmitted as it is without being absorbed by the glass substrates 2 and 3, and hardly generates heat even at the wavelength of 1064 nm. This is probably because of this. Therefore, according to the laser irradiation, the ITO that forms the transparent electrode layer and the liquid crystal alignment film layer are decomposed and removed at the atomic level mainly by ablation. It is considered that the smoothness can be obtained on the surfaces of the glass substrates 2 and 3 without causing damage.

  Next, a main sealant (product name: ES-7500, manufactured by Mitsui Chemicals, Inc.) containing 3% by weight of a gap control agent in the range of 2 to 5% by weight, for example, is applied onto the glass substrate 3 as the lower substrate. Then, the sealant layer 5 is formed. As the gap control agent, one having a diameter in the range of 3 to 15 μm can be used according to the thickness of the liquid crystal layer 4, and for example, a glass fiber having a diameter of 5 μm is used. The main sealant can be applied by, for example, screen printing or a dispenser.

  Next, a gap control agent made of, for example, a plastic ball having a diameter of 5 μm is sprayed on the glass substrate 2 as the upper substrate. The gap control agent can be sprayed using, for example, a dry gap sprayer.

  Next, the glass substrates 2 and 3 are overlapped so that the center points of the transparent electrode layers 6a and 7a overlap to form a cell, and a guest-host type liquid crystal is vacuum-injected into the cell to form the liquid crystal layer 4 To do. As the host liquid crystal, a liquid crystal having a negative Δε can be used, and a dichroic dye is added in the range of 2 to 15% by weight to the liquid crystal. The dichroic dye is preferably used by mixing at least three kinds of dyes, and usually 3 to 7 kinds of dyes, for example, five kinds of dyes are mixed and used. As the dichroic dye, a black dye (for example, trade name: S-428, manufactured by Mitsui Chemicals, Inc.) may be used. In addition, the liquid crystal has a chiral agent (trade name: S-811 manufactured by Merck & Co., Inc.) so that d / p is in the range of 0.5 to 1, for example, d / p = 0.75. It has been added to.

  Next, an end sealant is applied to the injection port of the guest-host type liquid crystal and sealed, thereby completing the camera diaphragm optical element 1a.

  The diaphragm optical element 1a for the camera according to this aspect operates as follows.

  First, in a state in which no voltage is applied, the liquid crystal molecules 4 in the liquid crystal layer 4 between the transparent electrode layers 6a, 6b, 6c, 6d and the transparent electrode layers 7a, 7b, 7c, 7d arranged to face each other The dichroic dye is oriented in the direction perpendicular to the glass substrates 2 and 3 and is almost transparent. In this state, the ratio of the area of the opening as the camera diaphragm is 100%.

  Next, when a voltage is applied between the transparent electrode layers 6a, 6b, 6c, 6d and the transparent electrode layers 7a, 7b, 7c, 7d, the liquid crystal molecules and the dichroic dye are applied to the glass substrates 2, 3. It becomes a colored state in which the color of the dichroic dye can be seen at an angle, and the coloring increases as the voltage increases. The spectral characteristics at this time are shown in FIG. From FIG. 3A, in the liquid crystal layer 4 between the transparent electrode layers 6a, 6b, 6c, and 6d and the transparent electrode layers 7a, 7b, 7c, and 7d, as the voltage increases, the color increases and the transmission It is clear that the rate decreases.

  On the other hand, in the portion where the transparent electrode layers 6a, 6b, 6c, 6d, the connection portion 9, and the transparent electrode layers 7a, 7b, 7c, 7d, the connection portions 10a, 10b, 10c, 10d are not formed, the liquid crystal alignment film No layer is formed. Therefore, in the said part, the liquid crystal molecule and the dichroic dye are in a state (amorphous orientation) aligned horizontally (parallel) with respect to the glass substrates 2 and 3, and the color of the dichroic dye is from the beginning. The color is visible. The spectral characteristics at this time are shown in FIG. From FIG. 3 (b), in the said part, when a high voltage is applied between the transparent electrode layers 6a, 6b, 6c, 6d and the transparent electrode layers 7a, 7b, 7c, 7d (shown in FIG. 3 (a)). It is in a state very similar to the case of 10V.

  Therefore, according to the diaphragm optical element 1a for a camera, a voltage is applied only between the transparent electrode layer 6d and the transparent electrode layer 7d, and the transparent electrode layers 6a, 6b, 6c and the transparent electrode layers 7a, 7b, 7c If no voltage is applied between them, only the transparent electrode layers 6d and 7d are colored, and the other portions are transparent. In this state, the ratio of the area of the opening as the camera diaphragm is 50%.

  In addition, a voltage is applied only between the transparent electrode layers 6d and 6c and the transparent electrode layers 7d and 7c, and no voltage is applied between the transparent electrode layers 6a and 6b and the transparent electrode layers 7a and 7b. Only the portions of the transparent electrode layers 6d and 6c and the transparent electrode layers 7d and 7c are colored, and the other portions are transparent. In this state, the ratio of the area of the opening as the camera diaphragm is 25%.

  Furthermore, a voltage is applied only between the transparent electrode layers 6d, 6c, 6b and the transparent electrode layers 7d, 7c, 7b, and no voltage is applied between the transparent electrode layer 6a and the transparent electrode layer 7a. Only the portions of the transparent electrode layers 6d, 6c, 6b and the transparent electrode layers 7d, 7c, 7b are colored, and the other portions are transparent. In this state, the ratio of the area of the opening as the camera diaphragm is 12.5%.

  Therefore, by selectively applying a voltage to the transparent electrode layers 6a, 6b, 6c, 6d and the transparent electrode layers 7a, 7b, 7c, 7d, the size of the transparent portion can be increased in multiple stages (in the above case). 4 stages), and the focus can be adjusted.

  Further, in the portion that is in a colored state, the degree of coloring can be adjusted by adjusting the applied voltage, so that the amount of light can be continuously adjusted.

  In this embodiment, the liquid crystal alignment film layer is not rubbed, but the liquid crystal alignment film layer may be rubbed. When the rubbing treatment is performed, it is preferable that the orientation direction between the glass substrates 2 and 3 is in a range of 90 to 360 °.

  Next, as shown in FIG. 4, the camera aperture optical element 1 b according to the second aspect of the present embodiment is disposed between the glass substrates 2 and 3 made of transparent plate glass and the glass substrates 2 and 3. The electrolyte layer 11 is sealed with a sealing agent layer 5 formed on the outer edges of the glass substrates 2 and 3. The glass substrate 2 includes transparent electrode layers 6 a, 6 b, 6 c, 6 d on the surface facing the glass substrate 3, and the glass substrate 3 has transparent electrode layers 7 a, 7 b, 7 c, 7d. The transparent electrode layers 6a, 6b, 6c, 6d, 7a, 7b, 7c, and 7d are made of, for example, ITO. An electrochromic film layer 12 is formed on the transparent electrode layers 7a, 7b, 7c, and 7d of the glass substrate 3.

  The transparent electrode layers 6a, 6b, 6c, and 6d formed on the glass substrate 2 have the same concentric pattern shape as the camera diaphragm optical element 1a. That is, the transparent electrode layers 6a, 6b, 6c, and 6d have a maximum diameter (corresponding to the outer diameter of the transparent electrode layer 6d) as a practical size in the range of 4 to 10 mm. The ratio can be changed in four stages of 100%, 50%, 25%, and 12.5%. Thus, for example, when the transparent electrode layer 6d has an outer diameter of 6 mm, the transparent electrode layer 6c has an outer diameter of 4.2 mm, the transparent electrode layer 6b has an outer diameter of 3.0 mm, and the transparent electrode layer 6a has a diameter of 2. The distance between the transparent electrode layers 6a, 6b, 6c, 6d is 60 μm. Each of the transparent electrode layers 6a, 6b, 6c and 6d is made the same as the diaphragm optical element 1a for the camera, and can be freely connected to an external power source via the connecting portion 9, and can be turned on / off at the same time.

  On the other hand, the transparent electrode layers 7a, 7b, 7c, and 7d formed on the glass substrate 3 form the same concentric pattern shape as the camera diaphragm optical element 1a. That is, the outer diameter of the transparent electrode layers 7d, 7c, 7b is the same as the outer diameter of the transparent electrode layers 6d, 6c, 6b, and the diameter of the transparent electrode layer 7a is the same as the diameter of the transparent electrode layer 6a. Yes. The intervals between the transparent electrode layers 7a, 7b, 7c, and 7d are the same as the intervals between the transparent electrode layers 6a, 6b, 6c, and 6d. Each of the transparent electrode layers 7a, 7b, 7c, and 7d is made the same as the diaphragm optical element 1a for the camera, and can be independently connected to an external power source via the connection portions 10a, 10b, 10c, and 10d. It can be turned on / off.

The electrochromic film layer 12 may be made of any material as long as it is an electrochromic film that switches between the transparent state and the colored state of the interface film. Examples of such an electrochromic film include tungsten trioxide (WO ₃ ), molybdenum oxide, tungsten oxide-molybdenum composite film, metal oxides such as vanadium oxide, iridium oxide, manganese dioxide, nickel oxide, viologen compounds, and styryl compounds. For example, an electrochromic film layer 12 made of tungsten trioxide can be used.

  The electrochromic film layer 12 can be formed by various printing methods such as vacuum deposition, sputtering such as RF magnetron sputtering, plating, LB, screen printing, spin coating, and die coating. It can be formed by the method.

  The electrochromic film layer 12 is not preferably a dense film structure, and is preferably an amorphous structure having many gaps. The electrochromic film layer 12 may positively disperse minute particles so as to have a structure having the gap.

  The aperture optical element 1b for a camera according to this aspect can be manufactured as follows, for example.

  First, a pair of glass substrates 2 and 3 having a transparent electrode layer made of ITO formed on the entire surface are prepared. The glass substrates 2 and 3 are made of transparent blue plate glass having a thickness of 0.4 mm, and the transparent electrode layer is formed to a thickness of 800 angstroms.

Next, a tungsten trioxide layer is formed on the transparent electrode layer of the glass substrate 3 by vacuum deposition, and heat treatment is performed at a temperature in the range of 300 to 550 ° C. for 20 to 60 minutes, for example, at 350 ° C. for 30 minutes. Next, the surface of the glass substrate 2 on which the transparent electrode layer is formed is irradiated with a YVO laser or a YAG laser, for example, a YVO laser (manufactured by YVO) having an output of 10 W and a wavelength of 1064 nm. A portion of the transparent electrode layer is removed to form a pattern shape shown in FIG. Further, the surface of the glass substrate 3 on which the transparent electrode layer and the electrochromic film layer are formed is irradiated with a YVO laser or a YAG laser, for example, a YVO laser (manufactured by YVO) having an output of 10 W and a wavelength of 1064 nm, and unnecessary portions. The transparent electrode layer is removed to form a pattern shape shown in FIG.

  The laser irradiation is preferably performed with an LD power in the range of 1 to 100%, a Q switch in the range of 10 to 100 kHz, and a moving speed in the range of 1 to 1500 mm / sec. The Q switch is 50 kHz and the moving speed is 500 mm / sec.

  As a result, the transparent electrode layers 6 a, 6 b, 6 c, 6 d and the connection portion 9 are obtained on the glass substrate 2. Moreover, on the glass substrate 3, transparent electrode layer 7a, 7b, 7c, 7d, connection part 10a, 10b, 10c, 10d, transparent electrode layer 7a, 7b, 7c, 7d, connection part 10a, 10b, 10c , 10d, the electrochromic film layer 12 is obtained.

  When the portion irradiated with the laser was observed with a microscope, the transparent electrode layer was completely removed on the glass substrate 2 and the surface of the glass substrate 2 was exposed. In the glass substrate 3, the transparent electrode layer and the electro The chromic film layer was completely removed, and the surface of the glass substrate 3 was exposed. The surface of the glass substrates 2 and 3 has a surface roughness of about 80 angstroms, but the surface roughness is comparable to the surfaces of the transparent electrode layers 6a, 6b, 6c, 6d, 7a, 7b, 7c and 7d. It has sufficient smoothness.

  The YVO laser is absorbed by ITO forming the transparent electrode layer, but is transmitted as it is without being absorbed by the glass substrates 2 and 3, and hardly generates heat even at the wavelength of 1064 nm. This is probably because of this. Therefore, according to the laser irradiation, the ITO forming the transparent electrode layer and the electrochromic film layer are decomposed and removed at the atomic level mainly by ablation, and the glass substrates 2 and 3 are almost completely removed. It is considered that the smoothness can be obtained on the surfaces of the glass substrates 2 and 3 without causing damage.

  Next, a main sealant (product name: ES-7500, manufactured by Mitsui Chemicals, Inc.) containing a gap control agent in the range of 2 to 5% by weight, for example, 5% by weight, is applied on the glass substrate 2 as the upper substrate. Then, the sealant layer 5 is formed. As the gap control agent, one having a diameter in the range of 50 to 200 μm can be used according to the thickness of the electrolyte layer 11. For example, a plastic ball having a diameter of 75 μm is used. The main sealant can be applied by, for example, screen printing or a dispenser.

  Next, the glass substrates 2 and 3 are overlapped so that the central points of the transparent electrode layers 6a and 7a overlap to form a cell, and an electrolyte is vacuum injected into the cell to form the electrolyte layer 11. Examples of the electrolytic solution include NaOH solutions, various liquid salts, and solvents such as acetonitrile. For example, NaOH solutions can be used.

  Next, an end sealing agent is applied to the electrolyte solution inlet and sealed to complete the diaphragm optical element 1b for the camera.

  The camera aperture optical element 1b of this aspect operates as follows.

  First, in a state where no voltage is applied, the portions where the transparent electrode layers 6a, 6b, 6c, 6d and the transparent electrode layers 7a, 7b, 7c, 7d that are arranged to face each other are almost transparent. Yes. In this state, the ratio of the area of the opening as the camera diaphragm is 100%.

  Next, when a voltage is applied between the transparent electrode layers 6a, 6b, 6c, 6d and the transparent electrode layers 7a, 7b, 7c, 7d, cations are injected from the electrolyte layer 11 into the electrochromic film layer 12, and the elect The chromic film layer 12 becomes colored, and coloring increases as the voltage increases. The spectral characteristics at this time are shown in FIG. From FIG. 4, it is clear that in the electrochromic film layer 12, as the voltage increases, the coloring increases and the transmittance decreases.

  Therefore, according to the diaphragm optical element 1b for a camera, a voltage is applied only between the transparent electrode layer 6d and the transparent electrode layer 7d, and the transparent electrode layers 6a, 6b, 6c and the transparent electrode layers 7a, 7b, 7c If no voltage is applied between them, only the transparent electrode layers 6d and 7d are colored, and the other portions are transparent. In this state, the ratio of the area of the opening as the camera diaphragm is 50%.

  In addition, a voltage is applied only between the transparent electrode layers 6d and 6c and the transparent electrode layers 7d and 7c, and no voltage is applied between the transparent electrode layers 6a and 6b and the transparent electrode layers 7a and 7b. Only the portions of the transparent electrode layers 6d and 6c and the transparent electrode layers 7d and 7c are colored, and the other portions are transparent. In this state, the ratio of the area of the opening as the camera diaphragm is 25%.

  Furthermore, a voltage is applied only between the transparent electrode layers 6d, 6c, 6b and the transparent electrode layers 7d, 7c, 7b, and no voltage is applied between the transparent electrode layer 6a and the transparent electrode layer 7a. Only the portions of the transparent electrode layers 6d, 6c, 6b and the transparent electrode layers 7d, 7c, 7b are colored, and the other portions are transparent. In this state, the ratio of the area of the opening as the camera diaphragm is 12.5%.

  Therefore, by selectively applying a voltage to the transparent electrode layers 6a, 6b, 6c, 6d and the transparent electrode layers 7a, 7b, 7c, 7d, the size of the transparent portion can be increased in multiple stages (in the above case). 4 stages), and the focus can be adjusted.

  At this time, in the diaphragm optical element 1a for the camera, the transparent electrode layers 6a, 6b, 6c, 6d, the connection portion 9, the transparent electrode layers 7a, 7b, 7c, 7d, and the connection portions 10a, 10b, 10c, 10d are formed. The electrochromic film layer is not formed in the part that is not formed. Therefore, coloring at a portion of the transparent electrode other than the transparent electrode to which a voltage is applied, that is, so-called crosstalk can be reliably prevented.

  Further, in the portion that is in a colored state, the degree of coloring can be adjusted by adjusting the applied voltage, so that the amount of light can be continuously adjusted.

  In this embodiment, the transparent electrodes 6a, 6b, 6c, 6d on the side of the glass substrate 2 on which no electrochromic film layer is formed are not subjected to any treatment, but on the transparent electrodes 6a, 6b, 6c, 6d. Alternatively, an electron donating film may be formed.

  According to the camera aperture optical elements 1a and 1b of the present embodiment, the transparent electrode layers 6a, 6b, 6c, and 6d are selectively selected from any one of the transparent electrode layers 7a, 7b, 7c, and 7d corresponding thereto. By applying a voltage to and adjusting the applied voltage, the light transmittance of the portion where each of the transparent electrodes 6a, 6b, 6c, 6d, 7a, 7b, 7c, 7d exists can be freely controlled. . Therefore, various light transmission states can be realized, and the photographing performance can be freely selected according to various photographing scenes, photographing environments and the like in the camera.

  For example, when it is desired to take a picture so that the whole image including the background is clearly displayed under a strong external light condition, voltage is applied to all of the transparent electrodes 6a, 6b, 6c, 6d and the transparent electrodes 7a, 7b, 7c, 7d. Is applied to reduce the amount of light hitting the photosensitive part of the camera. Further, when it is desired to focus and emphasize a nearby subject under strong external light, all other transparent electrodes 6b, 6c, 6d except the transparent electrode 6a at the center and the transparent electrode 7a are transparent. Focus adjustment can be performed by applying a voltage to the electrodes 7b, 7c, and 7d.

  The camera aperture optical elements 1a and 1b of the present embodiment are applied to, for example, digital still cameras in general, video cameras, security cameras, video cameras such as in-vehicle cameras, mobile phones with cameras, PDAs, personal computers, etc. Can do.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory sectional drawing which shows one Embodiment of the aperture_diaphragm | restriction optical element for cameras of this invention. The top view which shows the pattern shape of the transparent electrode layer in the aperture_diaphragm | restriction optical element for cameras shown in FIG. The graph which shows the spectral characteristic in the aperture_diaphragm | restriction optical element for cameras shown in FIG. Explanatory sectional drawing which shows other embodiment of the aperture stop optical element for cameras of this invention. The graph which shows the spectral characteristic in the aperture_diaphragm | restriction optical element for cameras shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a, 1b ... Diaphragm optical element for cameras, 2,3 ... Glass substrate, 4 ... Liquid crystal layer, 6a, 6b, 6c, 6d ... Transparent electrode layer, 7a, 7b, 7c, 7d ... Transparent electrode layer, 8 ... Liquid crystal orientation Membrane layer, 11 ... electrolyte layer, 12 ... electrochromic membrane layer.

Claims (3)

On one surface, a transparent electrode layer having a predetermined pattern and a liquid crystal alignment film layer formed on the transparent electrode layer, a pair of glass substrates in which the liquid crystal alignment film layers are arranged to face each other,
In a diaphragm optical element for a camera provided between a glass substrate and a liquid crystal layer containing a dichroic dye and a chiral agent,
The transparent electrode layer comprises a plurality of portions arranged concentrically on the glass substrate,
The diaphragm optical element for a camera, wherein the liquid crystal alignment film layer is provided on each of the plurality of portions of the transparent electrode layer.   2. The aperture optical element for a camera according to claim 1, wherein the alignment film layer for liquid crystal is composed of a vertical alignment film. Forming a transparent electrode layer on the entire surface of a pair of glass substrates;
Forming a liquid crystal alignment film layer on the entire surface of the transparent electrode layer formed on each glass substrate;
The surface of each glass substrate on which the transparent electrode layer and the alignment film layer for liquid crystal are formed is irradiated with laser, and the transparent electrode layer and the alignment film layer for liquid crystal are removed from the portion irradiated with the laser. Forming a transparent electrode layer having a plurality of portions arranged concentrically on each glass substrate, and forming the alignment film layer for liquid crystal on each of the plurality of portions of the transparent electrode layer A method of manufacturing a diaphragm optical element for a camera.

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