JP5665052B2 - Optical product for shading and shading glasses - Google Patents

Description

  The present invention relates to a light-shielding optical product or light-shielding glasses using the optical product.

  When the light from the light source directly enters the field of view, it diffuses in the eyeball and feels unpleasant glare. Such irregular reflection of direct light makes it difficult to recognize light from an object to be visually recognized, and a clear field of view cannot be secured. As a means for preventing such dazzling and poor visibility, a blind that blocks direct light or indirect illumination is performed. However, in these, the loss of light amount becomes large, and the place and the viewing direction are limited.

  Therefore, as the means, wearing sunglasses as light-shielding glasses using light-shielding optical products is performed. By wearing sunglasses, the amount of direct light incident on the eyeball can be reduced and anti-glare can be applied regardless of the location or viewing direction. As such sunglasses, those described in Patent Document 1 below are known. In this sunglasses, a substantially rectangular colored sunglasses (light-shielding lens) is used (see Patent Document 1 [0009] etc.) or a polarizing plate is used (see [0014] to [0017] etc.).

JP 2006-301287 A

  However, in the sunglasses described in Patent Document 1, the light from the object to be viewed is also shielded in the same way as the direct light, and the higher the light shielding performance, the more difficult it is to obtain a clear view. In addition, the higher the light shielding performance, the darker the color of the lens itself, and in some cases, the wearer's eyes cannot be seen by others. In particular, in order to effectively suppress irregular reflection in the eye, if it is configured to cut the short wavelength region of visible light, it becomes a hard yellow lens, but many users do not like such a yellow lens in appearance.

  SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a light-shielding optical product that has a favorable appearance and has a clear field of view while having light-shielding performance, or light-shielding glasses using the same. It is a thing.

In order to achieve the above object, the invention according to claim 1 is a light-blocking optical product comprising: a volume phase hologram formed by irradiating a hologram recording laser in an inclined state with respect to the hologram surface; with which the wavelength of the reflected light incident light is generated is reflected to the hologram surface of the volume phase hologram, it becomes one corresponding to the incident angle is the angle of the incident light relative to the normal of the hologram surface cage, the incident angle is equal to or less than the wavelength of the reflected light is 400nm when it is 0 °, the increased angle of incidence than 0 ° Then, the wavelength of the reflected light having portions ing the wavelength longer than 400nm It is characterized by.

In order to achieve the above object, the invention according to claim 2 is a light-blocking optical product comprising: a volume phase hologram formed by irradiating a hologram recording laser in a state inclined with respect to the hologram surface; with which the wavelength of the reflected light incident light is generated is reflected to the hologram surface of the volume phase hologram, it becomes one corresponding to the incident angle is the angle of the incident light relative to the normal of the hologram surface cage, wherein the wavelength of the reflected light when the incident angle is 0 ° is at 380nm or less, the increase the angle of incidence than 0 ° Then, the wavelength of the reflected light having portions ing the wavelength longer than 380nm It is characterized by.

  According to a third aspect of the present invention, in order to achieve the above object, the present invention provides a light-shielding spectacle and is made using the light-shielding optical product.

  According to the present invention, a volume phase hologram formed by irradiating a hologram recording laser in an inclined state with respect to the hologram surface is provided. Therefore, based on Bragg's law, it is possible to provide an optical product in which the wavelength of reflected light changes according to the angle with respect to the hologram surface. Further, the wavelength of the reflected light of the normal incident light is set to 400 (380) nm or less. Therefore, while allowing visible light incident perpendicularly to the hologram surface to pass, it is possible to reflect the short wavelength side and transmit the long wavelength side of visible light obliquely incident on the hologram surface from above. The angle and wavelength can be adjusted by changing the tilt angle of the laser. If the wavelength of the reflected light of the normal incident light is set to 400 nm or less, the vertically incident light can be clearly seen, and the light on the short wavelength side in the visible region can be cut out from the light from above. If the wavelength is 380 nm or less, an angle range that can be clearly seen (a vertical direction or a range that is obliquely upward from the direction by a predetermined angle) can be secured wider, and visible light from above is visible. The one on the short wavelength side in the region can be cut.

(A) is a schematic diagram which shows the optical product which concerns on this invention, (b) is a schematic diagram which shows the hologram recording of the optical product. It is a graph which shows the relationship between the angle of a perpendicular direction and the wavelength of the reflected light in the angle concerning the optical product of FIG.

  Hereinafter, examples of embodiments according to the present invention will be described. In addition, the form of this invention is not limited to the following.

  Fig.1 (a) is a schematic diagram which shows the optical product 1 as the said example. The optical product 1 is obtained by recording a volume phase hologram on a translucent substrate 2. The volume phase hologram is recorded on the hologram surface H of the substrate 2. The shape of the substrate 2 may be a circle or a block. Further, as the hologram surface H, any one surface or a surface inside the substrate 2 may be selected. Furthermore, an optical product may be formed by attaching a translucent cover that covers at least a part of the substrate 2 on which the hologram is recorded.

  FIG. 1B is a schematic diagram showing a hologram recording method in the optical product 1. The hologram recording lasers L1 and L2 are made incident on both surfaces of the base material 2 in such a direction that an angle (incident angle) formed with the surface of the base material 2 becomes a predetermined angle (here, 20 degrees).

  The lasers L1 and L2 are irradiated symmetrically in directions facing each other. The wavelengths of the lasers L1 and L2 are 488 nm (nanometers) here. The lasers L1 and L2 may be irradiated in directions that are not symmetrical, or other wavelengths may be selected as long as the output intensity necessary for recording can be secured.

  The lasers L1 and L2 serve as coherent reference light and object illumination light, and form a diffraction grating by interfering with the hologram surface H. The recording of the volume phase type hologram causes a change in the refractive index distribution. The direction of change in the refractive index distribution is along the bisector of the angle formed by the lasers L1 and L2. In other words, the layers having the same refractive index become one layer to form layers of each refractive index, and the direction of each layer is inclined with respect to the surface of the substrate 2 in a state perpendicular to the bisector direction. Yes.

The base material 2 on which the hologram is thus recorded has the following reflection characteristics with respect to light rays from an object or the like incident on the base material 2 based on Bragg's law. The Bragg condition in Bragg's law is that the angle between the direction of the refractive index layer and the light beam from the object is θ [°], the wavelength of the light beam from the object or the reflected light is λ [nm], the diffraction order Is n, and the distance between the diffraction gratings (same refractive index layers) is d [nm]. Although the diffraction order n is an integer, the intensity of the reflected light with n ≧ 2 is extremely small compared to the intensity of the reflected light with n = 1, so that only the case of n = 1 should be considered. Regarding d, it is not necessary to measure the actual layer spacing, and it can be obtained if the wavelength λ1 of light reflected at a specific angle θ1 is known.
2d sin θ = nλ

  That is, the base material 2 (optical product 1) on which hologram recording is performed by irradiating lasers L1 and L2 having a wavelength of 488 nm with an incident angle of 20 ° reflects light having a wavelength of 488 nm that is incident at an incident angle of 20 ° (θ = 90 °). Reflected as light R1. Therefore, the optical product 1 selectively reflects light of 488 nm as white light incident at an incident angle of 20 ° as reflected light R1. Such selective reflection with respect to wavelength follows the distribution of diffraction efficiency in a volume phase hologram. That is, at the incident angle, the light of 488 nm is diffracted most efficiently, and the diffraction efficiency decreases steeply when the angle is centered on the incident angle. It should be noted that the transmittance at the incident angle may be 0%, or a predetermined transmittance that is lower than the transmittance in other regions (for example, 20% relative to the transmittance of about 80% in other regions). Etc.).

  Further, when white light is incident with θ being decreased (increased angle with the substrate 2), the wavelength λ of the reflected light is also decreased due to the Bragg condition, and perpendicular incidence (θ = 20) with respect to the base material 2 is achieved. )), The wavelength λ of the reflected light R2 becomes 400 nm or less, and leaves the visible region.

  The optical product 1 having such characteristics can be used alone or in combination with other optical products such as lenses. In particular, the optical product 1 is used as a light-shielding spectacle by forming it as a spectacle lens with or without prescription, or the light product is formed by attaching the optical product 1 to the front and / or back of the lens substrate. It is possible to use it for light-shielding glasses, or to form a lens base material in a shape that is divided into a plurality of parts and sandwich the optical product 1 in the lens base material to make a light-shielding lens.

  FIG. 2 shows the relationship between the vertical angle [°] and the wavelength [nm] of reflected light in the case where light-shielding glasses are formed using the optical product 1 or two similar optical products as light-shielding lenses. Since these optical products are the same as the optical product 1 except that the incident angles of lasers at the time of hologram recording are different from each other, the following three optical products will be described using the same reference numerals as those of the optical product 1.

  The number in front of “30, 30” in FIG. 2 indicates the angle (incident angle [°]) between the front surface of the base material 2 and the surface of the base material 2 of the laser L1 during hologram recording. The later numbers are the angles (reflection angle [°]) between the laser L2 and the back of the base material 2 during hologram recording on the back side (eyeball side) of the base material 2. . In addition, the optical product as a light-shielding spectacle lens is arranged so that the laser L1 may be worn with the irradiation source on the upper side and the irradiation source with the laser L2 on the lower side. The same applies to “20, 20” and “10, 10”.

  In FIG. 2, “20, 20” is the optical product 1, and “10, 10” is an optical product formed by laying the lasers L1, L2 on the base material from the case of the optical product 1, and “30, 30 "is an optical product formed by raising the lasers L1 and L2 with respect to the base material 2 from the case of the optical product 1 described above.

  The vertical direction angle (viewed angle) is an angle that assumes the direction of the line of sight when viewed from the front side of the optical product, and 0 ° is an angle perpendicular to the base material 2 and the base material 2 is vertical. The horizontal direction in some cases (incident angle 90 °, θ = 20 °) is shown, a negative angle indicates an upper angle than when 0 °, and a positive angle indicates a lower angle than when 0 °. .

  In the optical product 1, the vertical angle is −30 °, and when viewed from the upper 30 ° direction, reflection of light having a wavelength of about 460 nm is observed. As the absolute value of the vertical angle decreases, the wavelength of the reflected light also decreases based on the Bragg condition. When the vertical angle becomes approximately −5 °, the wavelength is 400 nm or less, and the wavelength λ of the reflected light deviates from the visible region. To do. That is, the optical product 1 selectively reflects the short wavelength side in the visible region until the vertical angle becomes −5 °. As the vertical angle increases (because θ decreases), the wavelength λ of the reflected light further decreases. When the vertical angle reaches approximately 22 °, the wavelength λ of the reflected light cuts less than 300 nm. In this case, if the incident angle from above is less than 90 ° and the incident angle from below is more than 90 °, the reflected light wavelength is shorter than 400 nm when the incident angle increases from 90 °. It can be said that it will change.

  Further, in the optical product of “30, 30”, the change of the wavelength λ almost the same as that of the optical product 1 is observed. However, when compared at the same vertical angle, the wavelength λ is about 7 to 20 nm larger than that of the optical product 1. Therefore, when the vertical direction angle is about 0 °, it is 400 nm or less, and the wavelength λ is less than 300 nm when the vertical direction angle is about 28 °.

  On the other hand, in the optical product of “10, 10”, the change of the wavelength λ which is almost the same as that of the optical product 1 is observed. However, when compared at the same vertical angle, the wavelength λ is 7 to 20 nm smaller than that of the optical product 1. Therefore, when the vertical angle is about −8 °, the wavelength is 400 nm or less, and the wavelength λ is less than 300 nm when the vertical angle is about 18 °.

  The optical product 1 or the like described above includes a volume phase hologram formed by irradiating the hologram recording lasers L1 and L2 in an inclined state with respect to the hologram surface H (surface of the base material 2). The wavelength λ of the reflected light R1, R2, etc. that is generated by reflecting the incident light on the surface changes according to the incident angle of the incident light with respect to the hologram surface H. In the optical product 1, the wavelength λ of the reflected light R1 having an incident angle of 20 ° is 488 nm, and the wavelength λ of the reflected light R2 having an incident angle of 90 ° is about 380 nm.

  Therefore, it is possible to provide an optical product in which the wavelength of the reflected light is shifted according to the incident angle, and the angle at which the lasers L1 and L2 are tilted with respect to the hologram surface H is adjusted to obtain a desired incident angle. The wavelength of the corresponding reflected light can be obtained. For example, the laser wavelength that is sufficient output for hologram recording exists so that when recorded perpendicularly to the hologram surface H with a laser having a specific wavelength, the characteristic is only at that specific wavelength for perpendicular incident light. Although only a reflecting optical product can be provided, the optical product 1 or the like of the present invention can reflect with a wavelength of about 380 nm with respect to normal incident light even if it is recorded with a laser having a specified wavelength of 488 nm when irradiated at 20 °. Light can be exhibited, and if irradiated at 10 °, reflected light having a wavelength of about 360 nm can be exhibited with respect to normal incident light.

  Further, in the optical product 1, the wavelength of the reflected light R2 when the incident angle of the incident light with respect to the hologram surface H is 90 ° is 400 nm or less, and when the incident angle decreases from 90 °, the wavelength of the reflected light is 400 nm. It has a portion that changes to the longer wavelength side (for example, the wavelength of the reflected light R1 when the incident angle is 20 ° changes to 488 nm).

  Accordingly, when the incident angle is 90 °, the reflected light R2 comes out of the visible region, and consideration is given to good visibility and the like by sufficiently transmitting light in the 90 ° direction which is important with light-shielding glasses or the like. It is possible to make it look transparent when viewed from the normal direction of the base material 2 (the direction of the line of sight of the person facing the base material 2), which is the most seen direction. Can do.

  Moreover, when the portion that changes to the long wavelength side is directed upward, the light in the front direction from the object to be viewed is not directly cut in the visible region, but directly from the sun or illumination that is mostly located above. The component of the short wavelength side of the visible region can be cut by reflection, and most of the direct light comes from above, while the visual recognition is almost horizontal, and the indirect light from the visual object is horizontal. Efficient light shielding performance can be provided in accordance with the characteristics of receiving. In this case, when viewed from above, it will exhibit blue or yellow from the wavelength of the reflected light, but in light-shielding glasses etc., the possibility of being seen from above is extremely less than the possibility of being seen from the front, Since it is transparent as described above when viewed from the front, the appearance can be effectively improved while having light shielding performance.

  When the portion that changes to the short wavelength side is downward, the light from the lower front (lower objective side) is transmitted through the visible region, and the visibility is as good as in the vertical direction (front). Further, reflection of light from the lower rear (lower eyeball side) is also prevented, and a situation in which extra reflected light reaches the eyeball can be prevented, and visibility can be maintained well.

  Further, in the optical product of “10, 10”, that is, the optical product irradiated with the lasers L1 and L2 at the incident angle of 10 ° and the reflection angle of 10 °, the reflection when the incident angle of the incident light with respect to the hologram surface H is 90 °. When the wavelength of the light R2 is 380 nm or less and the incident angle is decreased from 90 °, the wavelength of the reflected light changes to a longer wavelength side than 380 nm (for example, the wavelength of the reflected light R1 at the incident angle of 10 ° is Change to 488 nm).

  Accordingly, it is possible to block the visible light in the front direction or in the range of about 10 ° above it, and to block the short wavelength side above it by reflection, and as with the optical product 1, it can block light efficiently. Thus, it is possible to provide an optical product with good appearance or visibility. Further, compared with the optical product 1, the visibility and the appearance can be further improved by slightly reducing the light shielding performance. Such adjustment of performance balance can be performed relatively easily by changing the tilt angle of the hologram recording laser.

  Note that the entire volume phase hologram may be used as an optical product, or an optical product may be formed by inserting a sheet-like volume phase hologram during polymerization molding of a plastic lens. It is also possible to produce a volume phase hologram by recording with a laser after the hologram recording agent is attached to, inserted into, or inserted into the lens. Furthermore, a hard coat layer, a primer layer, or the like can be formed on the front side or the back side of such an optical product or lens, an antireflection film can be formed, or an antifouling process can be applied.

  Further, the portion that changes to the long wavelength side can be arranged not on the upper side but on the lower side, or on the left side or the right side. Further, two optical products 1 are prepared and arranged symmetrically in the vertical direction to form one new optical product so that the wavelength of reflected light increases as the angle increases upward. The wavelength of the reflected light can be increased even when the angle is downward. In addition, it is possible to make the hologram surface curved, for example, by sticking a sheet-like optical product along the curved surface of the lens.

  In addition to the use of light-shielding glasses, the light-shielding optical product of the present invention includes a camera lens filter for light shielding that varies the reflection characteristics according to the incident angle of light, a microscope lens that emphasizes a specific observation portion, Or it can apply also to uses, such as a cover for a transmission lamp of a remote controller for preventing malfunction, and a window translucent plate that blocks high sunlight and receives low sunlight.

1 Optical product 2 Base material H Hologram surface L1, L2 Laser R1, R2 Reflected light

Claims (3)

It is equipped with a volume phase hologram formed by irradiating a hologram recording laser in a state inclined with respect to the hologram surface,
Wavelength of the reflected light incident light is generated is reflected to the hologram surface of the volume phase hologram, has a one corresponding to the angle of incidence angle is of the incident light relative to the normal of the hologram surface,
The wavelength of the reflected light when the incident angle is 0 ° is 400 nm or less,
Said increased angle of incidence than 0 ° Then, the light blocking optical products wavelength of the reflected light and having a long wavelength and ing portions than 400 nm. It is equipped with a volume phase hologram formed by irradiating a hologram recording laser in a state inclined with respect to the hologram surface,
Wavelength of the reflected light incident light is generated is reflected to the hologram surface of the volume phase hologram, has a one corresponding to the angle of incidence angle is of the incident light relative to the normal of the hologram surface,
The wavelength of the reflected light when the incident angle is 0 ° is 380 nm or less,
The incident angle is increased from 0 ° Then, the light blocking optical product characterized in that the wavelength of the reflected light having portions ing and wavelengths longer than 380 nm.   A light-shielding eyeglass produced by using the light-shielding optical product according to claim 1.

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