JP2009237226A - Electronic eyeglasses - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electronic eyeglasses which are free from blurring of an image and allow the dioptric power to be comfortably corrected even when brightness around a wearer is changed. <P>SOLUTION: The electronic eyeglasses include: an illuminance sensor; variable focus lenses which are provided so as to correspond to right and left eyes and have the focal lengths varied by a signal from the outside; and a focus control circuit which determines the focal lengths of the variable focus lenses in accordance with an output from the illuminance sensor. The focus control circuit includes: an illuminance calculation block for calculating illuminance in accordance with the output from the illuminance sensor; an calculation comparison block for calculating a comparative value between the illuminance calculated by the illuminance calculation block and a predetermined photopic or scotopic vision illuminance; and a driving control block for determining the focal lengths of the variable focus lenses in accordance with the calculation comparison result of the calculation comparison block. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic spectacle that electrically adjusts and controls the refractive power.

  As electronic glasses capable of changing the focal length, there is known a method in which the refractive power is variably controlled by changing the shape of the optical elastic lens by electrically controlling the pressure applied to the optical elastic lens (for example, patents). Reference 1).

Also, as electronic glasses that variably control refractive power electrically, a variable focus lens that controls refractive power by enclosing a dielectric material such as liquid crystal in the lens and applying a voltage to this to change the dielectric constant. There is a method used. The refractive index of a lens or variable focus lens depends on the wavelength. Therefore, in a lens or a variable focus lens, the refractive power in the visible wavelength range of 380 nm to 780 nm cannot be made the same. Therefore, it is necessary to adjust the refractive power of the variable focus lens. For example, the dielectric constant of the variable focus lens is changed so as to realize a predetermined refractive power at a wavelength of 550 nm where the specific luminous sensitivity of photopic vision is almost maximum. A method for performing control is known (for example, see Patent Document 2).
JP-A-63-24217 JP-A-11-352445

  However, in the conventional technique, the refractive power of the variable focus lens does not change even if the ambient brightness changes. For example, when the refractive power of the variable focus lens is controlled with reference to the wavelength of 550 nm, the wavelength of 550 nm is always controlled to have a predetermined refractive power even if the ambient brightness changes.

  In photopic vision where the surroundings are brighter than about 10 lux, the wavelength of maximum visual acuity is about 555 nm in order to sense light by the pyramidal cells on the retina, but about 0.01 lux or less In the scotopic vision with a brightness of about the moonlight, the wavelength of the maximum luminous efficiency is about 507 nm in order to sense light by the rod cells on the retina. In the morning glow at the midpoint between dark vision and photopic vision, and at dusk vision at dusk, light sensitivity is detected by both rod cells and cone cells depending on the brightness. The maximum wavelength varies depending on the brightness. Therefore, when the ambient brightness changes, the refractive power of the wavelength with the maximum specific visibility shifts from the predetermined refractive power required by the wearer, and there is a problem that the image is blurred because the focus is shifted. Was.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object of the present invention is to provide electronic glasses that can comfortably correct refractive power without blurring of an image even when the brightness around the wearer changes. .

  In order to solve the above-mentioned conventional problems, an electronic spectacle of the present invention includes an illuminance sensor, a variable focus lens whose focal length is changed by an external signal provided corresponding to the left and right eyes, and the illuminance sensor. And a focus control circuit for determining the focal length of the variable focus lens in accordance with the output of.

  The present invention solves the above-described conventional problems, and according to the electronic glasses equipped with the illuminance sensor, the focus control circuit, and the variable focus lens of the present invention, the optimum refractive power for the wearer according to the surrounding brightness. In addition, by driving and controlling the variable focus lens, it is possible to provide an electronic spectacle that realizes optimum correction of visual acuity without a bright defocus in a field of view under any brightness conditions.

  Embodiments of a refractive power control apparatus for electronic glasses according to the present invention will be described below in detail with reference to the drawings.

(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram of the electronic glasses according to Embodiment 1 of the present invention. The variable focus lens 1 is held by a rim 3. One set of the variable focus lens 1 and the rim 3 are connected and held by a bridge 5. A pair of nose pads 6 is provided on the bridge 5 in a portion that holds the electronic glasses in close contact with the nose when the electronic glasses are worn. Wigs 7 are provided at both ends of the rim 3, and are connected to the temple 4 through hinges 8. The temple 4 is provided with a focus control circuit 9 and a power source 10. The temple 4 is configured so that the electronic glasses are stably held on the side of the face and the ears when the electronic glasses are worn. The illuminance sensor 11 is provided in the wisdom 7. In this embodiment, the focus control circuit 9 and the power source 10 are provided in the temple 4 and the illuminance sensor 11 is provided in the wilt 7, but this is not particularly limited, and the focus control circuit 9 and the power source 10 are arranged in other components of the frame 2. Also good.

  FIG. 2 is a block diagram of the electronic glasses according to Embodiment 1 of the present invention. The illuminance sensor 11 detects the illuminance around the electronic glasses and sends an output corresponding to the illuminance to the focus control circuit 9. The focus control circuit 9 includes an illuminance calculation block 20, a calculation comparison block 21, and a drive control block 22. The illuminance calculation block 20 calculates the illuminance according to the output from the illuminance sensor 11. The operation comparison block 21 performs an operation comparison process between the value calculated by the illuminance calculation block 20 and a predetermined illuminance. The drive control block 22 performs adjustment control of the refractive power of the variable focus lens 1 in accordance with the calculation comparison result by the calculation comparison block 21. The variable focus lens 1, the power supply 10, and the illuminance sensor 11 are each electrically connected to the focus control circuit 9.

  FIG. 3 is a graph showing specific luminous efficiency characteristics of human eyes in photopic and scotopic visions. In the state of photopic vision (when viewed in a bright environment during the day), the human eye senses light by cone cells on the retina. Since the pyramidal cells are most sensitive to yellow-green light having a wavelength of approximately 555 nm, the specific luminous sensitivity characteristic in the photopic state is the characteristic 12 in FIG. The photopic illuminance is in a bright state of approximately 10 lux or more. In the scotopic state (when viewed in an environment of about moonlight), light is detected by the rod cells on the retina. Since rod cells are most sensitive to blue-green light having a wavelength of about 507 nm, the relative luminous sensitivity characteristic in the state of scotopic vision is the characteristic 13 in FIG. The illuminance in the dark place is in a dark environment of about 0.01 lux or less.

  FIG. 4 is an explanatory diagram of refractive power control of the electronic glasses according to Embodiment 1 of the present invention. A method for adjusting the refractive power control will be described with reference to FIG. In photopic vision in which the brightness is brighter than the third illuminance 16 of about 10 lux, as shown in the photosensitivity characteristic 12 of photopic vision in FIG. The relative visibility with respect to blue light on the short wavelength side and red light on the long wavelength side is significantly reduced. When the illuminance sensor 11 detects that the ambient illuminance is greater than or equal to the third illuminance of approximately 10 lux, the focus control circuit 9 can change the wavelength to achieve a predetermined refractive power optimum for the wearer to approximately 555 nm. The focus lens 1 is adjusted.

  In scotopic vision in which the brightness is darker than the second illuminance 15 of about 0.01 lux, the maximum wavelength of luminosity is about 507 nm as shown in the relative luminosity characteristic 13 of scotopic vision in FIG. Thus, the sensitivity at the wavelength of about 555 nm, which is the maximum specific visual sensitivity in the photopic state, is greatly reduced to 50% or less. When the illuminance sensor 11 detects that the ambient illuminance is less than or equal to the second illuminance of approximately 0.01 lux, the focus control circuit 9 can vary the wavelength that achieves the optimum refractive power for the wearer to approximately 507 nm. The focus lens 1 is adjusted.

  In the state of sunrise or dusk brightness between the second illuminance of about 0.01 lux and the third illuminance of about 10 lux, rod cells and cones according to the brightness. Light is sensed by both cells. In the case of illuminance close to that of scotopic vision in mesopic vision, the ratio of detecting light by the rod cells is larger than that of the cone cells, so that the specific luminous efficiency is close to the specific luminous sensitivity characteristic 13 of scotopic vision. . Further, in illuminance close to photopic vision in mesopic vision, the ratio of sensing light by cone cells is larger than that of rod cells, so that the specific visual sensitivity is close to the specific visual sensitivity characteristic 12 of photopic vision. In the first embodiment of the present invention, in the state of dim vision, the third illuminance 16 of approximately 10 lux that is the illuminance for photopic vision and the second illuminance 15 of approximately 0.01 lux that is the illuminance for scotopic vision. The control is switched at the first illuminance 14 between the two.

  In Embodiment 1 of FIG. 4, the case where 1 lux is 1 lux is shown. When the illuminance corresponding to the output of the illuminance sensor 11 is greater than 1 lux, the focus control circuit 9 is set so that the maximum specific vision sensitivity of photopic vision is approximately 555 nm and that the predetermined refractive power optimum for the wearer is realized. Thus, the variable focus lens 1 is adjusted. When the illuminance corresponding to the output of the illuminance sensor 11 is smaller than 1 lux, the focus control circuit 9 is set so that the maximum specific luminous sensitivity of scotopic vision is approximately 507 nm and realizes a predetermined refractive power optimum for the wearer. Thus, the variable focus lens 1 is adjusted. In FIG. 4, the first illuminance is 1 lux. However, the value is not particularly limited to this value, and may be a value between approximately 0.01 lux and approximately 10 lux in the state of dimming.

  FIG. 5 shows an explanatory diagram of the first design example in the first embodiment of the present invention. The optical material has a dispersion characteristic in which the refractive index changes depending on the wavelength of light. There is an Abbe number as a characteristic value representing the dispersion characteristic. The Abbe number is defined as follows. The refractive index of the C line (wavelength of 656.3 nm) is nC, the refractive index of the d line (wavelength of 587.6 nm) is nd, and the refractive index of the F line (wavelength of 486.1 nm) is nF. , Can be expressed by Equation 1.

  The Abbe number of general optical resin materials such as polycarbonate resin, acrylic resin, and urethane resin is about 25 to 80. However, when a nematic liquid crystal material is used as the material of the variable focus lens 1, the Abbe number is The value is about 20 to 40.

A predetermined refractive power required by the wearer as a first design example: D = 4 diopter (focal length f = 250 mm)
Abbe number of liquid crystal material of variable focus lens 1: V = 20
The case of the variable focus lens will be described with reference to FIG.

  FIG. 5A shows a refractive power adjustment state when the illuminance corresponding to the output of the illuminance sensor 11 is a value larger than the first illuminance 14. The variable focus lens 1 is adjusted by the focus control circuit 9 so that the wavelength of approximately 555 nm, which is the maximum specific vision sensitivity of photopic vision, is realized so as to realize the optimum refractive power D = 4 diopter (focal length f = 250 mm) for the wearer. ing.

  The refractive power state of the varifocal lens 1 shown in FIG. 5A is such that the wavelength of approximately 555 nm is adjusted to a refractive power D = 4 diopters optimum for the wearer, and the relative luminous sensitivity of scotopic vision is maximum. The wavelength of 507 nm is D = 4.1 (focal length f = 245 mm). Therefore, when the electronic glasses having the refractive power state (a) in the darkness of scotopic vision are worn, a wavelength of about 507 nm, which is the maximum specific luminosity sensitivity of scotopic vision, is the optimum refractive power D = 4 for the wearer. Since it is adjusted so as to deviate from the diopter, it is not in an appropriate refractive power correction state and is out of focus.

  FIG. 5B shows a refractive power adjustment state when the illuminance corresponding to the output of the illuminance sensor 11 is smaller than the first illuminance 14. The variable focus lens 1 is moved by the focus control circuit 9 so that the wavelength of about 507 nm, which is the maximum relative luminous sensitivity in the state of scotopic vision, realizes the optimum refractive power D = 4 diopter (focal length f = 250 mm) for the wearer. It has been adjusted. At a wavelength of about 555 nm, which is the maximum specific vision sensitivity for photopic vision, the specific visibility is greatly reduced to 50% or less in dark vision vision, and the refractive power is 3.9 diopters (focal length f = 255 mm). Thus, it is in a state deviating from the optimum refractive power required by the wearer.

  An explanatory diagram of the second design example in the first embodiment of the present invention is shown in FIG. 6 shows a case where a diffractive variable focus lens 19 composed of a diffractive lens 17 and a nematic liquid crystal material 18 is used as the variable focus lens 1 in the second design example of FIG. The material of the diffractive lens 17 may be polycarbonate resin, acrylic resin, urethane resin, or the like, but is not particularly limited thereto. The dispersion characteristic of the diffractive variable focus lens 19 that generates refractive power due to the diffraction phenomenon depends on the wavelength, and the Abbe number is that of the C-line (656.3 nm wavelength) is λC, and the d-line (587.6 nm wavelength). Assuming that the wavelength is λd and the wavelength of the F-line (wavelength of 486.1 nm) is λF, it can be expressed by Equation 2.

  As shown in Equation 2, the Abbe number of the diffractive variable focus lens 19 is −3.4, and the Abbe number of a normal optical resin material such as polycarbonate resin, acrylic resin, or urethane resin is about 25 to 80. On the other hand, the value is considerably small. Accordingly, the dispersion characteristics of the diffractive variable focus lens 19 with respect to the wavelength of light are poor, and the dependence of the refractive power (focal length) on the wavelength becomes very large.

As a second design example, the refractive power required by the wearer: D = 4 diopters (focal length f = 250 mm)
Abbe number of diffractive variable focus lens: V = -3.4
The case where the diffractive variable focus lens 19 composed of the diffractive lens 17 and the nematic liquid crystal material 18 is used will be described with reference to FIG.

  FIG. 6A shows a refractive power adjustment state when the illuminance corresponding to the output of the illuminance sensor 11 is a value larger than the first illuminance 14. The diffractive variable focus lens 19 is moved by the focus control circuit 9 so that the wavelength of approximately 555 nm, which is the maximum specific luminous sensitivity for photopic vision, realizes the optimum refractive power D = 4 diopter (focal length f = 250 mm) for the wearer. It has been adjusted.

  The refractive power state of the diffractive variable focus lens 19 in FIG. 6A is such that the wavelength of approximately 555 nm is adjusted to a refractive power D = 4 diopters that is optimal for the wearer, and the relative luminous sensitivity of scotopic vision is maximum. The wavelength of about 507 nm is D = 3.7 (focal length f = 270 mm). Therefore, when the electronic glasses having the refractive power state (a) in the darkness of scotopic vision are worn, a wavelength of about 507 nm, which is the maximum specific luminosity sensitivity of scotopic vision, is the optimum refractive power D = 4 for the wearer. Since it is adjusted to a state greatly deviated from the diopter, it is not in an appropriate refractive power correction state and is in a defocused state.

  FIG. 6B shows the refractive power adjustment state when the illuminance corresponding to the output of the illuminance sensor 11 is smaller than the first illuminance 14. The diffractive variable focus lens 19 is a focus control circuit so that a wavelength of about 507 nm, which is the maximum relative luminous sensitivity in the state of scotopic vision, realizes an optimum refractive power D = 4 diopter (focal length f = 250 mm) for the wearer. 9 is adjusted. At a wavelength of about 555 nm, which is the maximum specific vision sensitivity for photopic vision, the specific visibility is greatly reduced to 50% or less in dark vision vision, and the refractive power is 4.3 diopters (focal length f = 230 mm). Thus, it is in a state deviating from the optimum refractive power required by the wearer.

  In the first embodiment, a liquid crystal type lens is described as an example of the variable focus lens 1, but a variable focus lens capable of adjusting the refractive power by electrical control, such as a hydraulic lens type or a photonic crystal lens type. I just need it.

  As described above, in the first embodiment, the illuminance sensor 11 detects ambient illuminance, and according to the output, the wavelength having the maximum specific visual acuity has a predetermined refractive power required by the wearer. The variable focus lens 1 is adjusted in two stages by the focus control circuit 9. By this adjustment control, by correcting the refractive power suitable for the wearer in accordance with the surrounding illuminance, it is possible to realize electronic glasses that are free of focus shift even if the surrounding illuminance changes.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIG. FIG. 7 is an explanatory diagram of the refractive power control of the electronic glasses according to the second embodiment of the present invention. Hereinafter, a method for adjusting the refractive power control will be described with reference to FIG. In photopic vision where the illuminance corresponding to the output from the illuminance sensor 11 is brighter than the third illuminance 16 of approximately 10 lux, light is sensed by the pyramidal cells on the retina. As shown in the photopic characteristic 12 of photopic vision in FIG. 3, the maximum wavelength of specific luminous efficiency is about 555 nm, and the relative luminous sensitivity to blue light on the short wavelength side and red light on the long wavelength side is significantly reduced. Accordingly, when the illuminance sensor 11 detects the ambient illuminance as the third illuminance 16 or more of about 10 lux, the focus control circuit 9 is set so that the wavelength for realizing the predetermined refractive power optimum for the wearer is about 555 nm. Thus, the variable focus lens 1 is adjusted.

  In scotopic vision where the illuminance corresponding to the output from the illuminance sensor 11 is darker than the second illuminance 15 of approximately 0.01 lux, light is sensed by the rod cells on the retina. As shown in the relative luminous sensitivity characteristic 13 of dark vision in FIG. 3, the maximum wavelength of specific luminous efficiency is approximately 507 nm, and the sensitivity of the wavelength of approximately 555 nm, which is the maximum relative luminous efficiency in photopic vision, is 50% or less. Decrease significantly. When the illuminance sensor 11 detects that the ambient illuminance is less than or equal to the second illuminance of approximately 0.01 lux, the focus control circuit 9 can vary the wavelength that achieves the optimum refractive power for the wearer to approximately 507 nm. The focus lens 1 is adjusted.

  The brightness in accordance with the output from the illuminance sensor 11 is in the state of morning glow or dusk lightness between the second illuminance of approximately 0.01 lux and the third illuminance of approximately 10 lux. In response to this, light is sensed by both rod cells and cone cells. In the case of illuminance close to that of scotopic vision in mesopic vision, the ratio of detecting light by the rod cells is larger than that of the cone cells, so that the specific luminous efficiency is close to the specific luminous sensitivity characteristic 13 of scotopic vision. . Further, in illuminance close to photopic vision in mesopic vision, the ratio of sensing light by cone cells is larger than that of rod cells, so that the specific visual sensitivity is close to the specific visual sensitivity characteristic 12 of photopic vision. Therefore, between about 0.01 lux and about 10 lux, the wavelength with the highest specific luminous efficiency is between the wavelength with the highest relative visual sensitivity for scotopic vision of about 507 nm and the wavelength with the highest relative visual sensitivity for photopic vision of about 555 nm. Change.

  In Example 2 of the present invention, as shown in FIG. 7, the wavelength that realizes the optimum predetermined refractive power for the wearer in accordance with the output of the illuminance sensor 11 is approximately 507 nm in the state of thin vision. The variable focus lens 1 is adjusted by the focus control circuit 9 so as to continuously change to approximately 555 nm. By making such adjustments, the optimal refractive power correction of the wearer at a wavelength with high specific vision sensitivity according to the brightness even in the state of mesopic vision where light is sensed by both rod cells and cone cells Can be realized.

  In the second embodiment, the wavelength that achieves the appropriate refractive power for the wearer continuously changes from approximately 507 nm, which is the maximum specific luminous sensitivity for scotopic vision, to approximately 555 nm, which is the maximum specific luminous sensitivity for photopic vision. As described above, the variable focus lens 1 was adjusted by the focus control circuit 9. However, the adjustment control method is not particularly limited to this, and as shown in FIG. 8, over a wavelength range from about 507 nm at the maximum relative luminous sensitivity for scotopic vision to about 555 nm at the maximum relative luminous sensitivity for photopic vision. The variable focus lens 1 may be adjusted by the focus control circuit 9 so as to change intermittently.

  As described above, in the second embodiment, the illuminance sensor 11 detects ambient illuminance, and according to the output, the wavelength having the maximum specific visual acuity has a predetermined refractive power required by the wearer. The variable focus lens 1 is adjusted by the focus control circuit 9. This adjustment control makes it possible to correct the refractive power optimal for the wearer in accordance with the ambient illuminance, and to realize electronic glasses that are not out of focus even if the ambient illuminance changes.

  The electronic glasses according to the present invention detect ambient brightness by an illuminance sensor, and perform adjustment control of the refractive power of the variable focus lens by a focus control circuit according to the output. This makes it possible to correct the optimal refractive power in focus even if the surrounding brightness environment changes, so electronic glasses for correcting abnormal refractive power in the human eye such as myopia, hyperopia and presbyopia Etc. are useful.

Schematic diagram of electronic glasses in Embodiment 1 of the present invention Block diagram of electronic glasses in Embodiment 1 of the present invention A graph showing the relative visibility characteristics of human eyes in photopic and scotopic vision Explanatory drawing of refractive power control of the electronic spectacles in Embodiment 1 of this invention Explanatory drawing of the 1st design example in Embodiment 1 of this invention Explanatory drawing of the 2nd design example in Embodiment 1 of this invention Explanatory drawing of refractive power control of the electronic spectacles in Embodiment 2 of this invention Explanatory drawing of refractive power control of the electronic spectacles in Embodiment 2 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Variable focus lens 2 Frame 3 Rim 4 Temple 5 Bridge 6 Nose pad 7 Satoshi 8 Hinge 9 Focus control circuit 10 Power supply 11 Illuminance sensor 12 Specific luminous efficiency characteristic of photopic vision 13 Specific luminous characteristic characteristic of dark vision 14 1st Illuminance 15 Second illuminance 16 Third illuminance 17 Diffractive lens 18 Nematic liquid crystal 19 Diffractive variable focus lens 20 Illuminance calculation block 21 Operation comparison block 22 Drive control block

Claims (8)

An illuminance sensor;
A variable focal length lens whose focal length is changed by an external signal provided corresponding to the left and right eyes;
Electronic glasses comprising: a focus control circuit that determines a focal length of the variable focus lens according to an output from the illuminance sensor. The focus control circuit includes:
2. The electronic glasses according to claim 1, wherein focal lengths of the left and right variable focus lenses are simultaneously determined according to an output from the illuminance sensor. The focus control circuit includes:
An illuminance calculation block that calculates illuminance according to the output from the illuminance sensor;
A calculation comparison block for calculating a comparison value between the illuminance calculated by the illuminance calculation block and a predetermined dark place illuminance or photopic illuminance;
The electronic spectacles of Claim 1 provided with the drive control block which determines the focal distance of the said variable focus lens according to the calculation comparison result by the said calculation comparison block. The drive control block includes:
When the comparison value is smaller than the scotopic illuminance, determine the focal length of the variable focus lens so as to be the focal length of the maximum luminous efficiency relative wavelength in scotopic vision,
4. The electronic glasses according to claim 3, wherein when the comparison value is larger than the photopic illuminance, the focal length of the variable focus lens is determined so as to be a focal length of a maximum luminous efficiency relative wavelength in photopic vision. . The drive control block includes:
When the comparison value is larger than the scotopic illuminance and smaller than the photopic illuminance, the ratio in photopic vision from the focal length of the maximum luminous efficiency relative wavelength in scotopic vision according to the illuminance. The electronic spectacles of Claim 3 which determine the focal distance of the said variable focus lens in the range of the focal distance of a visibility maximum wavelength. The drive control block includes:
When the comparison value is larger than the scotopic illuminance and smaller than the photopic illuminance, the ratio in photopic vision from the focal length of the maximum luminous efficiency relative wavelength in scotopic vision according to the illuminance. The electronic spectacles of Claim 4 which determine the focal distance of the said variable focus lens in the range of the focal distance of a visibility maximum wavelength. The electronic glasses according to claim 3, wherein the dark place illuminance is approximately 0.01 lux, and the bright place illuminance is approximately 10 lux. The electronic spectacles according to claim 4 or 5, wherein the maximum wavelength of specific luminous efficiency in the dark place vision is about 507 nm, and the maximum wavelength of specific visibility in the photopic vision is about 555 nm.

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