1. An optical device which guides illuminating light from a light source, comprising:
a columnar light-guiding unit including an incidence face which the illuminating light from the light source is incident upon, an emission face which emits the illuminating light and has a larger area than the incidence face, and a reflection face which guides rays of the illuminating light which is incident from the incidence face to the emission face while bringing the rays to total internal reflection; and
a holder which secures the columnar light-guiding unit in position for the light source,
wherein the columnar light-guiding unit and the holder are connected together in a single piece only on the reflection face on the emission face side of the columnar light-guiding unit, and
the holder includes a connector for connecting to the light source, the connector being disposed further to the incidence face side than the emission face side.
2. The optical device according to claim 1, wherein a plurality of the reflection faces are disposed on the columnar light-guiding unit, and one of the holders is joined to each of two of the reflection faces.
3. An illumination apparatus comprising: the optical device according to claim 1; and
a light source which includes a light-emitting diode which emits illuminating light and a base which holds the light-emitting diode,
wherein the holder is secured in position to the base such that the incidence face is opposite the light-emitting diode.
4. The illumination apparatus according to claim 3, wherein the base is provided with a positioning section for positioning for the incidence face.
5. The illumination apparatus according to claim 3, wherein the holder is adhesively secured to the base with the connector therebetween.
6. The illumination apparatus according to claim 5, further comprising:
a convexity which is formed on the connector and protrudes in the direction of the base; and
a concavity which is formed in the base and allows the convexity to be inserted therein.
7. The illumination apparatus according to claim 3, further comprising a securing section which secures the connector to the base.
8. The illumination apparatus according to claim 7, wherein the connector protrudes toward the base, and the securing section further comprises an engaging groove which the connector attached to the base can be engaged into, and a clasping member which securely engages and fastens the connector into the engaging groove.
9. The illumination apparatus according to claim 7, wherein the securing section further comprises:
a holder side through-hole which is provided in the connector and faces the base side;
a base side through-hole which is provided in the base and can be aligned with the holder side through-hole; and
a pointed pin which can be inserted through the holder side through-hole and the base side through-hole.
10. The illumination apparatus according to claim 9, wherein the pin is long enough to protrude from the base side through-hole when inserted therein, forming a protruding section, and the protruding section is thermally crimped to the base.
11. The illumination apparatus according to claim 7, wherein the securing section further comprises:
a pointed pin which is formed in a single piece with the connector and protrudes in the direction of the base; and
a base side through-hole which is formed in the base and allows the pin to be inserted.
12. The illumination apparatus according to claim 11, wherein the pin is long enough to protrude from the base side through-hole when inserted therein, forming a protruding section, and the protruding section is thermally crimped to the base.
13. The illumination apparatus according to claim 7, wherein the securing section comprises:
a holder side through-hole which is provided in the connector and faces the base side;
an external screw section which can be inserted through the holder side through-hole; and
an internal screw section which is provided in the base and allows the external screw section to be screwed therein after insertion through the holder side through-hole.
14. The illumination apparatus according to claim 9, further comprising:
a convexity which is formed on the connector and protrudes in the direction of the base; and
a concavity which is formed in the base and allows the convexity to be inserted therein.
15. An optical device which guides illuminating light from a light source, comprising:
a columnar light-guiding unit including an incidence face which the illuminating light from the light source is incident upon, an emission face which emits the illuminating light and has a larger area than the incidence face, and a reflection face which guides rays of the illuminating light which is incident from the incidence face to the emission face while bringing the rays to total internal reflection; and
a holder which secures the columnar light-guiding unit in position for the light source,
wherein the columnar light-guiding unit and the holder are connected together in a single piece only on the reflection face on the emission face side of the columnar light-guiding unit,
the columnar light-guiding unit and the holder are molded in a single piece of the same material, and
the holder includes a connector for connecting to the light source, the connector being disposed further to the incidence face side than the emission face side.
16. An optical device which guides illuminating light from a light source, comprising:
a columnar light-guiding unit including an incidence face which the illuminating light from the light source is incident upon, an emission face which emits the illuminating light and has a larger area than the incidence face, and a reflection face which guides rays of the illuminating light which is incident from the incidence face to the emission face while bringing the rays to total internal reflection; and
a holder which secures the columnar light-guiding unit in position for the light source,
wherein the columnar light-guiding unit and the holder are connected together in a single piece only on the reflection face on the emission face side of the columnar light-guiding unit,
the holder includes a connector for connecting to the light source, the connector being disposed further to the incidence face side than the emission face side, and
the distance between the emission face and the connector is approximately the same as the distance between the emission face and the incidence face.
17. An optical device which guides illuminating light from a light source, comprising:
a columnar light-guiding unit including an incidence face which the illuminating light from the light source is incident upon, an emission face which emits the illuminating light and has a larger area than the incidence face, and a reflection face which guides rays of the illuminating light which is incident from the incidence face to the emission face while bringing the rays to total internal reflection; and
a holder which secures the columnar light-guiding unit in position for the light source,
wherein the columnar light-guiding unit and the holder are connected together in a single piece only on the reflection face on the emission face side of the columnar light-guiding unit,
the columnar light-guiding unit and the holder are molded in a single piece of a same material,
the holder includes a connector for connecting to the light source, the connector being disposed further to the incidence face side than the emission face side, and
the distance between the emission face and the connector is approximately the same as the distance between the emission face and the incidence face.
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. A method for reducing the time to determine data packet routes on a computer network, the method comprising:
(a) providing a forwarding process for looking up routing information from a memory to route a data packet on the computer network, wherein a plurality of original second protocol entries stored in the memory each include second protocol information for a second protocol, and wherein a plurality of first protocol combined entries stored in the memory each include first protocol information for a first protocol and cached second protocol information retrieved from an associated original second protocol entry, wherein the forwarding process includes a lookup in the memory to find a particular first protocol combined entry in the memory, the lookup obtaining the first protocol information and the cached second protocol information to provide a route for the data packet, and wherein the first protocol is different from the second protocol; and
(b) providing a background maintenance process for maintaining the coherency of the cached associated second protocol information so that the cached second protocol information does not become stale when the original second protocol entries get updated.
2. The method of claim 1, wherein the first protocol is an exterior gateway protocol (EGP), and wherein the second protocol is an interior gateway protocol (IGP).
3. The method of claim 2 wherein the background maintenance task maintains coherency by invalidating the cached second protocol information in each of the combined entries individually once the update to the original second protocol entries is made.
4. The method of claim 3 wherein the combined entries are invalidated individually by storing an invalid indicator in each of the combined entries.
5. The method of claim 3 wherein the forwarding process re-caches the updated second protocol information into the combined entries after the background maintenance task invalidates the combined entries.
6. The method of claim 3 wherein the background maintenance task runs in parallel to the forwarding process.
7. A computer readable storage medium including program instructions that perform a method on a computer device for reducing the time to determine data packet routes on a computer network, the program instructions performing steps comprising:
(a) providing a forwarding process for looking up routing information from a memory to route a data packet on the computer network, wherein a plurality of original second protocol entries stored in the memory each include second protocol information for a second protocol, and wherein a plurality of first protocol combined entries stored in the memory each include first protocol information for a first protocol and cached second protocol information retrieved from an associated original second protocol entry, wherein the forwarding process includes a lookup in the memory to find a particular first protocol combined entry in the memory, the lookup obtaining the first protocol information and the cached second protocol information to provide a route for the data packet, and wherein the first protocol is different from the second protocol; and
(b) providing a background maintenance process for maintaining the coherency of the cached associated second protocol information so that the cached second protocol information does not become stale when the original second protocol entries get updated.
8. The computer readable medium of claim 7, wherein the first protocol is an exterior gateway protocol (EGP), and wherein the second protocol is an interior gateway protocol (IGP).
9. The computer readable medium of claim 8, wherein the background maintenance task maintains coherency by invalidating each of the first protocol combined entries individually once the update to the original second protocol entries get updated.
10. A method for allowing the reduction of time for lookup and resolution of data packet routes on a computer network, the data packet routes requiring a first protocol and a second protocol, the method comprising the steps of:
(a) for a plurality of second protocol entries stored in a memory of an electronic apparatus, storing second protocol information for the second protocol from each second protocol entry into a cache in an associated first protocol entry storing first protocol information for the first protocol in the memory to allow the information from both entries to be read with a single lookup to the first protocol entry, wherein the information from both entries is used to resolve a first protocol route for a packet of data on the computer network, and wherein the second protocol is different from the first protocol;
(b) invalidating the cache in all first protocol entries when a change to at least one of the second protocol entries is made; and
(c) after the change to at least one of the second protocol entries is made, repeating the storing of information from second protocol entries into the caches in associated first protocol entries.
11. The method of claim 10, wherein the first protocol is an exterior gateway protocol (EGP), and wherein the second protocol is an interior gateway protocol (IGP).
12. A method as recited in claim 11 further comprising performing a lookup in the memory tree to find one of the EGP entries in the memory tree when receiving a data packet to be routed on the network, wherein the information from the EGP entry and the information stored in the cache of the EGP entry is used to resolve an EGP route for a packet of data on the computer network.
13. A method as recited in claim 12 wherein the lookup in the memory tree is not permitted when the cache in all EGP entries has been invalidated, and wherein the lookup is permitted after the repeated storing of information from the IGP entries into the caches in the associated EGP entries.
14. A method as recited in claim 11 wherein invalidating the cache in all EGP entries includes invalidating each of the caches stored in the memory individually.
15. A method as recited in claim 14 wherein the invalidating of caches individually is performed by a background maintenance task that is running in parallel with a process implementing the storing of IGP information in the caches.
16. A method as recited in claim 14 wherein the invalidating of the caches includes resetting a global flag when a change to at least one of the IGP entries is made.
17. A method as recited in claim 16 wherein the invalidating of the caches individually includes accessing each of the EGP entries individually and resetting a local flag in each of the EGP entries.
18. A computer readable storage medium including program instructions that perform a method on a computer device for allowing the reduction of time for lookup and resolution of data packet routes on a computer network, the program instructions performing steps comprising:
(a) for a plurality of interior gateway protocol (IGP) entries stored in a memory of an electronic apparatus, storing IGP information from each IGP entry into a cache in an associated external gateway protocol (EGP) entry storing EGP information in the memory to allow the information from both entries to be read with a single lookup to the memory, wherein the information from both entries is used to resolve a EGP route for a packet of data on the computer network;
(b) invalidating the cache in all EGP entries when a change to at least one of the IGP entries is made; and
(c) after the change to at least one of the IGP entries is made, repeating the storing of information from IGP entries into the caches in associated EGP entries.
19. A method for reducing the time to determine data packet routes on a computer network, the method comprising the steps of:
performing a single lookup in a memory tree to find a particular first protocol forwarding entry in the memory tree to determine a first protocol route for a packet of data to be routed on the computer network, wherein the first protocol forwarding entry includes first protocol information for a first protocol and a cache of associated second protocol information for a second protocol different from the first protocol, and wherein the first protocol is an exterior gateway protocol (EGP) and the second protocol is an interior gateway protocol (JGP);
determining whether the cached second protocol information associated with one or more first protocol entries in the search tree has been invalidated due to an update to at least one original second protocol entry in the search tree; and
retrieving and using the cached second protocol information in the determination of the first protocol route for the packet of data on the computer network.
20. The method of claim 19, wherein if the cached IGP information has been invalidated, the lookup is a first lookup, and further comprising:
performing a second lookup in the memory tree by retrieving and using the EGP information to find an original IGP entry in the memory tree; and
using the found original IGP entry in the determination of the destination for the packet of data.
21. The method of claim 20, further comprising a step of caching the information in the original IGP entry found in the second lookup into the first protocol forwarding entry found in the first lookup.
22. A computer readable storage medium including program instructions that perform a method on a computer device for reducing the time to determine data packet routes on a computer network, the program instructions performing steps comprising:
performing a single lookup in a memory tree to find a particular first protocol forwarding entry in the memory tree to determine a first protocol route for a packet of data to be routed on the computer network, wherein the first protocol forwarding entry includes first protocol information for a first protocol and a cache of associated second protocol information for a second protocol different from the first protocol, wherein both the first protocol information and cached second protocol information are retrievable with the single lookup, and wherein the first protocol is an exterior gateway protocol (EGP) and the second protocol is an interior gateway protocol (JGP);
determining whether the cached second protocol information associated with one or more first protocol forwarding entries in the search tree has been invalidated due to an update to at least one second protocol entry in the search tree, and wherein if the cached second protocol information has been invalidated, then further comprising:
(a) performing a second lookup in the memory tree is performed to find an original second protocol entry in the memory tree; and
(b) using the information in the original second protocol entry in the determination of the destination for the packet of data; and
if the cached second protocol information has not been invalidated, using the cached second protocol information in the determination of the first protocol route for the packet of data on the computer network.
23. A method for reducing the time to determine data packet routes on a computer network, the method comprising:
(a) performing a first lookup in a memory tree to find a particular first protocol forwarding entry in the memory tree to determine a first protocol route for a packet of data to be routed on the computer network, wherein the first protocol forwarding entry includes first protocol information for a first protocol and a cache of associated second protocol information for a second protocol different from the first protocol, wherein both the first protocol information and cached second protocol information are retrievable with the first lookup;
(b) determining whether the cache associated with one or more first protocol forwarding entries in the search tree is valid or has been invalidated due to an update to at least one original second protocol entry in the search tree;
(c) if the cache is valid, using the cached second protocol information to determine a destination for the packet of data on the computer network; and
(d) if the cache has been invalidated, performing a second lookup in the memory tree using the first protocol information to find the original second protocol entry in the memory tree associated with the first protocol forwarding entry found in the first lookup, wherein the associated original second protocol entry is used to determine the destination for the packet of data on the computer network.
24. A method as recited in claim 23 wherein the method is performed by a network processor provided in a router on the computer network.
25. A method as recited in claim 23 wherein the memory tree is implemented in Dynamic Random Access Memory (DRAM).
26. The method of claim 23, wherein the first protocol is an exterior gateway protocol (EGP), and wherein the second protocol is an interior gateway protocol (IGP).
27. A method as recited in claim 26 wherein the EGP is Border Gateway Protocol (BGP) and at least a portion of the computer network is the Internet.
28. A method as recited in claim 26 wherein the update to at least one IGP entry in the search tree is due to a change in configuration of the network.
29. The method of claim 26, further comprising a step of caching the information in the IGP entry found in the second lookup in the first protocol forwarding entry found in the first lookup.
30. A method as recited in claim 29 wherein a portion of the forwarding entries of the memory tree are stored in Static Random Access Memory (SRAM).
31. A method as recited in claim 29 wherein the caches of all of the EGP entries are invalidated once the update to at least one original IGP entry in the search tree has been made by storing a global validation indicator.
32. A method as recited in claim 31 further comprising a step of invalidating the caches in each of the EGP forwarding entries individually once the update to at least one original IGP entry in the search tree has been made by storing an invalid indicator in each of the EGP forwarding entries.
33. A method as recited in claim 32 wherein the information in the original IGP entry found in the second lookup is not cached in the EGP forwarding entry found in the first lookup if the caches of all the EGP forwarding entries are still invalidated at the time of the second lookup.
34. A method as recited in claim 29 further comprising a step of invalidating the caches in each of the EGP forwarding entries individually once the update to at least one original IGP entry in the search tree has been made by storing an invalid indicator in each of the EGP forwarding entries.
35. A method as recited in claim 34 wherein the invalid indicator stored in each of the EGP forwarding entries is a validity flag that has been reset.
36. A method as recited in claim 34 wherein the information in the original IGP entry found in the second lookup is cached only if the caches stored with all the EGP entries in the memory tree have been individually invalidated.
37. A method as recited in claim 36 wherein the individual invalidation of the caches in all the EGP entries is performed by a background maintenance task that runs in parallel to the lookup steps.
38. A computer readable storage medium including program instructions that perform a method on a computer device for reducing the time to determine data packet routes on a computer network, the program instructions performing steps comprising:
(a) performing a first lookup in a memory tree to find a particular first protocol forwarding entry in the memory tree to determine a first protocol route for a packet of data to be routed on the computer network, wherein the first protocol forwarding entry includes first protocol information for a first protocol and a cache of associated second protocol information for a second protocol different from the first protocol, wherein both the first protocol information and cached second protocol information are retrievable with the first lookup;
(b) determining whether the cache associated with one or more first protocol forwarding entries in the search tree is valid or has been invalidated due to an update to at least one original second protocol entry in the search tree;
(c) if the cache is valid, using the cached second protocol information to determine a destination for the packet of data on the computer network; and
(d) if the cache has been invalidated, performing a second lookup in the memory tree using the first protocol information to find the original second protocol entry in the memory tree associated with the first protocol forwarding entry found in the first lookup, wherein the associated original second protocol entry is used to determine the destination for the packet of data on the computer network.
39. The computer readable medium of claim 38, further comprising a step of caching the information in the original second protocol entry found in the second lookup into the first protocol forwarding entry found in the first lookup.
40. The computer readable medium of claim 38, wherein the information in the second protocol entry found in the second lookup is not cached in the first protocol forwarding entry found in the first lookup if all the first protocol forwarding entries are still invalidated at the time of the second lookup.
41. The computer readable medium of claim 38, wherein the first protocol is an exterior gateway protocol (EGP), and wherein the second protocol is an interior gateway protocol (IGP).