1. A kit for a firewall penetration system for use between a firewall and a penetrating member, the kit comprising:
a first annular plate having an outer and an inner radial wall and an axial wall coupled therebetween, the axial wall extending axially away from the outer radial wall, and the inner radial wall extending radially inwardly from the axial wall, the inner radial wall having an inner peripheral edge defining an opening through which the penetrating member may extend;
a second annular plate having an outer section, an inner section, and an inner peripheral edge, the outer section configured to couple to the first annular plate outer radial wall, the inner section configured to define a seal cavity with the first annular plate axial wall and inner radial wall when the first and second annular plates are coupled together, and the inner peripheral edge defining an opening; and
a compressible seal configured to be disposed in the seal cavity, the compressible seal having a bulb and a leg extending therefrom.
2. The kit of claim 1, wherein the compressible seal is mounted to the first annular plate axial wall.
3. The kit of claim 1, wherein the compressible seal is a dual bulb compressible seal.
4. The kit of claim 3, wherein the dual bulb compressible seal includes a pilot bulb and the pilot bulb is configured to be installed adjacent the inner radial wall.
5. The kit of claim 1, wherein the compressible seal is integrally formed as an annulus.
6. The kit of claim 1, wherein the compressible seal comprises woven fabric having a first end and a second end stitched together.
7. The kit of claim 1, wherein the compressible seal comprises a strip of woven fabric having a first end and a second end bonded together.
8. The kit of claim 1, wherein the compressible seal includes a shape memory material coupled thereto that is configured to cause the compressible seal to form a predetermined cross-sectional shape upon exposure to a predetermined temperature.
9. The kit of claim 1, wherein at least one of the first and second annular plates comprises fireproof material.
10. The kit of claim 9, wherein at least one of the first and second annular plates comprises fiber reinforced plastic composite.
11. The kit of claim 10, wherein at least one of the first and second annular plates comprises graphite-bismaleimide.
12. The kit of claim 1, wherein each of the first and the second annular plates each comprise more than one piece.
13. A firewall penetration system disposed between a firewall and a penetrating member, the system comprising:
a first annular plate having a first section and a second section, each section including an outer radial wall, an inner radial wall and an axial wall coupled therebetween, the axial wall extending axially away from the outer radial wall, the inner radial wall extending radially inwardly from the axial wall, the inner radial wall having an inner peripheral edge defining a first space within which the penetrating member is at least partially disposed;
a second annular plate having a first section and a second section, each section including an outer section, an inner section, and an inner peripheral edge, the outer section coupled to the first annular plate outer radial wall, and the inner peripheral edge defining a second space within which the penetrating member is at least partially disposed;
a seal cavity defined by the second annular plate inner section, the first annular plate axial wall, and first annular plate inner radial wall; and
a compressible seal disposed in the seal cavity, the compressible seal having ends that are joined together such that a ring is formed.
14. The system of claim 13, wherein the compressible seal includes a shape memory material coupled thereto that is configured to cause the compressible seal to form a predetermined cross-sectional shape upon exposure to a predetermined temperature.
15. The system of claim 13, wherein at least one of the first and second annular plates comprises fireproof material.
16. The system of claim 15, wherein at least one of the first and second annular plates comprises fiber reinforced plastic composite.
17. The system of claim 16, wherein at least one of the first and second annular plates comprises graphite-bismaleimide.
18. The system of claim 13, wherein the compressible seal is coupled to at least a portion of the first annular plate axial wall.
19. The system of claim 13, wherein the compressible seal is a dual bulb compressible seal.
20. The system of claim 19, wherein the dual bulb compressible seal includes a pilot bulb and the pilot bulb is configured to be installed adjacent the first annular plate inner radial wall.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An optical element having at least one surface divided into a plurality of regions, the optical element comprising:
a first region including an optical axis and configured to converge light with a wavelength \u03bb1 onto a storage surface of a first optical disc and converge light with a wavelength \u03bb2 onto a storage surface of a second optical disc; and
a second region formed around the outer circumference of the first region and configured to converge light with the wavelength \u03bb1 onto the storage surface of the first optical disc and converge light with the wavelength \u03bb2 onto the storage surface of the second optical disc, wherein
the first region has a first diffraction structure cyclically formed on an aspheric surface and having a step-like cross section,
the second region has a second diffraction structure cyclically formed on an aspheric surface and having a step-like cross section, and
in the first region, the number of steps included between top portions of the first diffraction structure is different from the number of steps included between the optical axis and a top portion that is closest to the optical axis in the first diffraction structure.
2. An optical element having at least one surface divided into a plurality of regions, the optical element comprising:
a first region including an optical axis and configured to converge light with a wavelength \u03bb1 onto a storage surface of a first optical disc and converge light with a wavelength \u03bb2 onto a storage surface of a second optical disc; and
a second region formed around the outer circumference of the first region and configured to converge light with the wavelength \u03bb1 onto the storage surface of the first optical disc and converge light with the wavelength \u03bb2 onto the storage surface of the second optical disc, wherein
the first region has a first diffraction structure cyclically formed on a first aspheric surface and having a step-like cross section, and
the second region has a second diffraction structure cyclically formed on a second aspheric surface and having a step-like cross section, and
the optical element satisfying the following conditions:
\u22120.25<(\u03a611+\u03a612)\u2212N1<0.25\u2003\u2003(1)
\u22120.25<(\u03a621+\u03a622)\u2212N2<0.25\u2003\u2003(2)
where,
\u03a611 is a phase difference with reference to a phase at the first aspheric surface, \u03a611 being given by a step in the first region, that is closest to the second region, for light with the wavelength \u03bb1 to be converged onto the first optical disc,
\u03a612 is a phase difference with reference to a phase at the second aspheric surface, \u03a612 being given by a step in the second region, that is closest to the first region, for light with the wavelength \u03bb1 to be converged onto the first optical disc,
\u03a621 is a phase difference with reference to the phase at the first aspheric surface, \u03a621 being given by the step in the first region, that is closest to the second region, for light with the wavelength \u03bb2 to be converged onto the second optical disc,
\u03a622 is a phase difference with reference to the phase at the second aspheric surface, \u03a622 being given by the step in the second region, that is closest to the first region, for light with the wavelength \u03bb2 to be converged onto the second optical disc,
N1 is an integer obtained by rounding the first decimal place of a numerical value given by \u03a611+\u03a612, and
N2 is an integer obtained by rounding the first decimal place of a numerical value given by \u03a621+\u03a622.
3. The optical element according to claim 2, the optical element being an objective lens and satisfying the following conditions:
\u03a611=d1\xd7cos {s1(0.2\xd7f+1.1)}\xd7(n1\u22121)\u03bb1\u2003\u2003(3)
\u03a612=d2\xd7cos {s2(0.2\xd7f+1.1)}\xd7(n1\u22121)\u03bb1\u2003\u2003(4)
\u03a621=d1\xd7cos {s1(0.2\xd7f+1.1)}(n2\u22121)\u03bb2\u2003\u2003(5)
\u03a622=d2 cos {s2(0.2\xd7f+1:1)}\xd7(n2\u22121)\u03bb2\u2003\u2003(6)
where,
d1 is the height of the step in the first region, that is closest to the second region, from the first aspheric surface in the optical axis direction,
d2 is the height of the step in the second region, that is closest to the first region, from the second aspheric surface in the optical axis direction,
s1 is an inclination angle deg made by the outermost step in the first region with respect to a plane perpendicular to the optical axis,
s2 is an inclination angle deg made by the innermost step in the second region with respect to the plane perpendicular to the optical axis,
f is a focal length mm of the objective lens,
n1 is a refractive index of the optical element for the wavelength and
n2 is a refractive index of the optical element for the wavelength \u03bb2.
4. The optical element according to claim 1, wherein the diffraction structure in the first region is a step-like diffraction structure having five to nine steps per one cycle.
5. The optical element according to claim 1, wherein
the diffraction structure in the second region is a step-like diffraction structure having three to eight steps per one cycle, and
the number of steps in one cycle of the diffraction structure in the second region is less than the number of steps in one cycle of the diffraction structure in the first region.
6. The optical element according to claim 1, wherein
the wavelength \u03bb1 is 350 to 450 nm, and
the wavelength \u03bb2 is 600 to 800 nm.
7. An optical head apparatus comprising the optical element according to claim 1.
8. The optical element according to claim 2, wherein the diffraction structure in the first region is a step-like diffraction structure having five to nine steps per one cycle.
9. The optical element according to claim 2, wherein
the diffraction structure in the second region is a step-like diffraction structure having three to eight steps per one cycle, and
the number of steps in one cycle of the diffraction structure in the second region is less than the number of steps in one cycle of the diffraction structure in the first region.
10. The optical element according to claim 2, wherein
the wavelength \u03bb1 is 350 to 450 nm, and
the wavelength \u03bb2 is 600 to 800 nm.
11. An optical head apparatus comprising the optical element according to claim 2.