Image display device, wire grid polarizing plate, method of manufacturing plate, method of observing wire grid polarizing plate, and method of estimating polarization axis direction of wire grid polarizing plate
To provide an image display device for enabling a polarization axis direction of a reflection type polarizing plate to be identified with simplicity and accuracy, and enabling an adjustment in the polarization reflection axis direction to be made with high accuracy, a wire grid polarizing plate for enabling the polarization axis direction to be examined simply, and the like, a head-up display device ( 1 ) in the present invention is an image display device provided with an image display ( 14 ) that outputs image light which is polarized light, a reflection type polarizing plate ( 15 ) having an reflecting surface ( 28 ) that reflects the image light, and a projection plate ( 11 ) onto which the image light reflected by the reflection type polarizing plate is projected, and is characterized in that the reflection type polarizing plate allows a bright line (B) as an indicator indicative of the polarization axis direction of the reflecting surface to be observed.
1. A wire grid polarizing plate comprising:
a plurality of fine metal wires each extending in a predetermined direction to form a fine metal wire region so that a polarization reflection axis direction of the wire grid polarizing plate is substantially parallel to the predetermined direction; and
a plurality of different fine metal wires that are directly adjacent to each other, each having a structure different from that of peripheral fine metal wires of the plurality of fine metal wires, the plurality of different fine metal wires being provided within the fine metal wire region so as to form an abnormal structure region for emitting diffracted light in reflection observation, and the plurality of different fine metal wires in the abnormal structure region being configured to emit the diffracted light as a line that corresponds to a polarizing direction of the surface having the fine metal wire region.
2. The wire grid polarizing plate according to claim 1 , wherein each of the different fine metal wires is at least one selected from the group consisting of a fine metal wire provided in the wire grid polarizing plate to form a broken line, and a fine metal wire having a width or a height different from that of the peripheral fine metal wires.
3. The wire grid polarizing plate according to claim 2 , wherein each of the plurality of different fine metal wires is the fine metal wire having a width or a height different from that of the peripheral fine metal wires.
4. The wire grid polarizing plate according to claim 1 , wherein an extension direction of each of the plurality of different fine metal wires is substantially parallel with the predetermined direction in which the plurality of fine metal wires extend.
5. The wire grid polarizing, plate according to claim 1 , wherein each of the plurality of different fine metal wires has a width or a height different in a range of 3% or more from that of the peripheral fine metal wires.
6. The wire grid polarizing plate according to claim 5 , wherein each of the plurality of different fine Metal wires has a structure where the width or the height of the fine metal wire is different in a range of 3% to 60% from that of the peripheral fine metal wires.
7. The wire grid polarizing plate according to claim 1 , wherein a distance between the fine metal wires m the fine metal wire region ranges from 50 nm to 150 nm.
8. The wire grid polarizing plate according to claim 1 , further comprising:
a substrate having a concavo-convex structure extending in a particular direction on a surface thereof, wherein the plurality of fine metal wires is provided on the concave-convex structure of the substrate.
9. The wire grid polarizing plate according to claim 8 , wherein the plurality of fine metal wires is provided to be unevenly distributed on one-side surfaces of convex portions of the concave-convex structure of the substrate.
10. The wire grid polarizing plate according to claim 8 , wherein the concavo-convex structure of the substrate includes a convex portion having a structure different from that of peripheral convex portions.
11. The wire grid polarizing plate according to claim 8 , wherein the concavo-convex structure of the substrate includes the convex portion having a structure where a width or a height is different in a range of 3% to 60% from that of the peripheral convex portions.
12. The wire grid polarizing plate according to claim 8 , wherein a distance between convex portions of the concavo-convex structure of the substrate ranges from 50 nm to 150 nm.
13. The wire grid polarizing plate according to claim 1 , wherein each of the plurality of different fine metal wires has a portion having a length ranges from 50 nm to 800 nm.
14. The wire grid polarizing plate according to claim 13 , wherein the length of the portion of each of the plurality of different line metal wires is the same as or less than a wavelength of light desired for polarization separation.
15. The wire grid polarizing plate according to claim 1 , wherein a width of the abnormal structure region, in a direction perpendicular to a direction in which the different fine metal wires extend, ranges from 50 nm to 800 nm.
16. The wire grid polarizing plate according to claim 1 , wherein a width of the abnormal structure region in a direction perpendicular to a direction in which each of the plurality of different fine metal wires extends is the same as or less than a wavelength of light desired for polarization separation.
17. The wire grid polarizing, plate according to claim 1 , wherein a width of the abnormal structure region in a direction, in which the different fine metal wires of the abnormal structure region extend, ranges from 50 nm to 800 nm.
18. The wire grid polarizing plate according to claim 1 , a width of the abnormal structure region in a direction in which the fine metal wires of the abnormal structure region extend is the same as or less than a wavelength of light desired for polarization separation.
19. A method of observing a polarizing direction of the fine metal wire region of the wire grid polarizing plate of claim 1 , the method comprising:
applying light to a surface having the fine metal wire region of the wire grid polarizing plate; and
observing the surface having the fine metal wire region of the wire grid polarizing plate from an angle that is not a regular reflection direction of the light applied, so as to observe the line that corresponds to a polarizing direction of the surface having the fine metal wire region.
20. The method according to claim 19 , wherein a polarization axis direction of a wire grid polarizing plate is estimated by the observation.
21. A method of manufacturing a wire grid polarizing plate having a fine metal wire region, comprising:
a fine metal wire forming step of forming a plurality of fine metal wires extending in a predetermined direction on a substrate to form the fine metal wire region; and
a step of forming a plurality of different fine metal wires that are directly adjacent to each other, each having a structure different from that of peripheral fine metal wires on the substrate to be included in the fine metal wire region at a same time as, or at a different step from, the fine metal wire forming step, so that the plurality of different fine metal wires are formed within the fine metal wire region and provide Han an abnormal structure region for emitting diffracted light in reflection observation, wherein the diffracted light is a line that corresponds to a polarizing direction of the surface having the fine metal wire region.
22. The method of manufacturing the wire grid polarizing plate according to claim 21 , further comprising:
a concavo-convex structure forming step of forming a concavo-convex structure extending in the predetermined direction on the substrate; and
a step of forming a convex portion having a structure different from that of peripheral convex portions on the substrate at a same time or a different step as/from the concavo-convex structure forming step.
23. The method of manufacturing the wire grid polarizing plate according to claim 21 , wherein the plurality of fine metal wires contains aluminum.