As a result of a fourth surface being a surface on a gate side, a merging position of a molten resin material during molding of a lens array main body is placed away from formation positions of lens faces, and as a result of the three dimensional shape of a third recessing section, during molding of the lens array main body, the flow of molten resin material from a surface side that opposes the fourth surface into a flow path corresponding with an area between a first recessing section and a second recessing section can be suppressed.

In recent years, in reflection of the need for higher-speed communication and more compact communication devices, there has been an increasing demand for a lens array in which a plurality of lenses are arranged in parallel, as a compactly structured optical component effective for actualizing multichannel optical communication.
This type of lens array is conventionally configured such that a photovoltaic device including a plurality of light-emitting elements (such as a vertical cavity surface emitting laser [VCSEL]) can be attached thereto and a plurality of optical fibers can be attached thereto.
In a state in which the lens array is disposed between the photovoltaic device and plurality of the optical fibers in this way, the lens array optically couples light emitted from each light-emitting element of the photovoltaic device to an end face of each optical fiber. As a result, multichannel optical communication can be performed.
In addition, among photovoltaic devices, some include a monitoring light-receiving element for monitoring light (particularly intensity or amount of light) emitted from the light-emitting elements to stabilize the output characteristics of the light-emitting elements. A lens array supporting such photovoltaic devices is configured to reflect some of the light emitted from the light-emitting elements towards the monitoring light-receiving element as monitor light.
Furthermore, among the photovoltaic devices, some include a receiving light-receiving element in addition to the light-emitting elements to support bidirectional communication. A lens array supporting such photovoltaic devices include a lens for reception in addition to a lens for transmission.
An example of the lens array supporting light monitoring and an example of the lens array supporting bidirectional communication will hereinafter be described in sequence.
(Light Monitoring-supporting Lens Array)
First, FIG. 20 is a vertical cross-sectional view showing a lens array 1 supporting light monitoring, together with a photovoltaic device 2 and optical fibers 3. In addition, FIG. 21 is a planar view of a lens array main body in the lens array 1 shown in FIG. 20. FIG. 22 is a left-side view of the lens array main body shown in FIG. 20. FIG. 23 is a bottom view of the lens array main body shown in FIG. 20. FIG. 24 is a right-side view of the lens array main body shown in FIG. 20.
As shown in FIG. 20, the lens array 1 is disposed between the photovoltaic device 2 and the optical fibers 3.
Here, the photovoltaic device 2 has a plurality of light-emitting elements 7 on a surface of a semiconductor substrate 5 facing the lens array 1, the light-emitting elements 7 emitting laser light La in a direction perpendicular to the surface (upward direction in FIG. 20). The light-emitting elements 7 configure the above-described VCSEL. In FIG. 20, the light-emitting elements 7 are formed in an array along a direction perpendicular to the surface of the paper on which FIG. 20 is printed. In addition, the photovoltaic device 2 has a plurality of monitoring light-receiving elements 8 on the surface of the semiconductor substrate 5 facing the lens array 1, in positions near the left-hand side in FIG. 20 of the light-emitting elements 7. The light-receiving elements 8 receive monitor light M for monitoring the output (such as intensity or amount of light) of the laser light La emitted from the light-emitting elements 7. The number of light-receiving elements 8 is the same as the number of light-emitting elements 7. The light-receiving elements 8 are formed in an array in the same direction as the light-emitting elements 7. The positions in the array direction match between corresponding elements 7 and 8. In other words, the light-receiving elements 8 are formed at the same pitch as the light-emitting elements 7. The light-receiving elements 8 are configured by photodetectors or the like. Furthermore, a control circuit (not shown) that controls the output of the laser light La emitted from the light-emitting elements 7 based on the intensity and the amount of light of the monitor light M received by the light-receiving elements 8 is connected to the photovoltaic device 2. The photovoltaic device 2 such as this is configured, for example, to be arranged opposing the lens array 1 in a state in which the semiconductor substrate 5 is in contact with the lens array 1. The photovoltaic device 2 together with the lens array 1 configures an optical module by, for example, being attached to the lens array 1 by a known fixing means (not shown) such as a clamp spring.
In addition, the same number of optical fibers 3 as the number of light-emitting elements 7 and the number of light-receiving elements 8 are arranged. The optical fibers 3 are formed in an array at the same pitch as the light-emitting elements 7 along the direction perpendicular to the surface of the paper on which FIG. 20 is printed in FIG. 20. The optical fibers 3 have the same dimensions as one another. A portion of each optical fiber 3 on an end face 3a side is held within a multi-core integrated optical connector 10, such as a mechanically transferable splicing connector (MT connector). The optical fibers 3 such as this are, for example, attached to the lens array 1 by a known fixing means (not shown) (such as a clamp spring) in a state in which an end surface of the optical connector 10 on the lens array 1 side is in contact with the lens array 1.
The lens array 1 optically couples each light-emitting element 7 with the end face 3a of each optical fiber 3 in a state in which the lens array 1 is disposed between the photovoltaic device 2 and the optical fibers 3 such as those described above.
The lens array 1 will be described in further detail. As shown in FIG. 20, the lens array 1 has a light-transmissive lens array main body 4. The outer shape of the lens array main body 4 is formed into a substantially rectangular plate shape. In other words, as shown in FIG. 20 and FIG. 21, the rough outer shape of the lens array main body 4 is configured by each planar surface: an upper end surface 4a, a lower end surface 4b, a left end surface 4c, a right end surface 4d, a front end surface 4e, and a back end surface 4f. The upper and lower end surfaces 4a and 4b are parallel with each other. The left and right end surfaces 4c and 4d are also parallel with each other. Furthermore, the upper and lower end surfaces 4a and 4b and the left and right end surfaces 4c and 4d are perpendicular to each other.
The photovoltaic device 2 is attached to the lower end surface 4b of the lens array main body 4 such as this. As shown in FIG. 20 and FIG. 23, a plurality (12 lens faces) of first lens faces (convex lens faces) 11 having a circular planar shape are formed on the lower end surface 4b. The number of first lens faces 11 is the same as the number of light-emitting elements 7. Here, as shown in FIG. 20, a portion having a substantially rectangular planar shape in a predetermined area on the right side in FIG. 20 of the lower end surface 4b is formed into a recessing plane (referred to, hereinafter, as a lens formation surface 16a) that recesses further upwards than other portions with a counterbore 16 therebetween. The plurality of first lens faces 11 are formed on the lens formation surface 16a on the lower end surface 4b such as this. However, the lens formation surface 16a is formed in parallel with the other portions of the lower end surface 4b. In addition, the first lens faces 11 are formed such as to be arrayed in a predetermined array direction (the direction perpendicular to the surface of the paper on which FIG. 20 is printed in FIG. 20, and a vertical direction in FIG. 23) corresponding with the light-emitting elements 7. Furthermore, the first lens faces 11 are formed having the same dimensions as one another and are formed at the same pitch as the light-emitting elements 7. Still further, the first lens faces 11 that are adjacent to each other in the array direction are formed in an adjoining state in which respective peripheral end sections are in contact with each other. In addition, an optical axis OA(1) of each first lens face 11 is formed perpendicular to the lower end surface 4b of the lens array main body 4. Moreover, the optical axis OA(1) of each first lens face 11 is formed to match a center axis of the laser light La emitted from each light-emitting element 7 corresponding with each first lens face 11.
As shown in FIG. 20, the laser light La emitted from each light-emitting element 7 corresponding with each first lens face 11 enters each first lens face 11. Each first lens face 11 advances the incident laser light La of each light-emitting element 7 into the lens array main body 4. Each first lens face 11 collimates the incident laser light La of each light-emitting element 7 in some instances, and converges the incident laser light La in other instances.
On the other hand, the plurality of optical fibers 3 are attached to the left end surface 4c of the lens array main body 4. As shown in FIG. 20 and FIG. 22, a plurality of second lens faces (convex lens faces) 12 having a circular planar shape are formed on the left end surface 4c. The number of second lens faces 12 is the same as the number of the first lens faces 11. Here, as shown in FIG. 20 and FIG. 22, a portion having a substantially rectangular planar shape in a predetermined area in the center of the left end surface 4c is formed into a recessing plane (referred to, hereinafter, as a lens formation surface 17a) that recesses further to the right in FIG. 20 than other portions on the peripheral side surrounding the portion with a counterbore 17 therebetween. The plurality of second lens faces 12 are formed on the lens formation surface 17a on the left end surface 4c such as this. However, the lens formation surface 17a is formed in parallel with the other portions of the left end surface 4c. In addition, the second lens faces 12 are formed such as to be arrayed in the same direction as the array direction of the end faces 3a of the optical fibers 3, or in other words, the array direction of the first lens faces 11. Furthermore, the second lens faces 12 are formed having the same dimensions as one another and are formed at the same pitch as the first lens faces 11. Still further, the second lens faces 12 that are adjacent to each other in the array direction are formed in an adjoining state in which respective peripheral end sections are in contact with each other. In addition, an optical axis OA(2) of each second lens face 12 is formed perpendicular to the left end surface 4c of the lens array main body 4. Moreover, the optical axis OA(2) of each second lens face 12 is formed to be positioned coaxially with the center axis of the end face 3a of each optical fiber 3 corresponding with each second lens face 12.
The laser light La of each light-emitting element 7 that has entered each first lens face 11 corresponding with each second lens face 12 and advanced on an optical path within the lens array main body 4 enters each second lens face 12, as shown in FIG. 20. Each second lens face 12 converges the incident laser light La of each light-emitting element 7 and emits the converged laser light La to the end face 3a of each optical fiber 3a corresponding with each second lens face 12.
In this way, each light-emitting element 7 and the end face 3a of each optical fiber are optically coupled by the first lens face 11 and the second lens face 12.
Furthermore, as shown in FIG. 20 and FIG. 23, third lens faces (convex lens face) 13 having a circular planar shape are formed on the lens formation surface 16a on the lower end surface 4b of the lens array main body 4, in positions near the left-hand side in FIG. 20 of the first lens faces 11. The number of third lens faces 13 is the same as the number of the light-receiving elements 8 (according to the present embodiment, the number of third lens faces 13 is also the same as the number of light-emitting elements 7, the number of optical fibers 3, the number of first lens faces 11, and the number of second lens faces 12). The third lens faces 13 are formed such as to be arrayed in a predetermined array direction corresponding with the light-receiving elements 8, or in other words, the same direction as the array direction of the first lens faces 11. Furthermore, the third lens faces 13 are formed having the same dimensions as one another and are formed at the same pitch as the light-receiving elements 8. Still further, the third lens faces 13 that are adjacent to each other in the array direction are formed in an adjoining state in which respective peripheral end sections are in contact with each other. In addition, an optical axis OA(3) of each third lens face 13 is formed perpendicular to the lower end surface 4b of the lens array main body 4. Moreover, the optical axis OA(3) of each third lens face 13 is formed to almost match the center axis of a light-receiving surface of each light-receiving element 8 corresponding with each third lens face 13.
The monitor light M of each light-emitting element 7 corresponding with each third lens face 13 enters each third lens face 13 from within the lens array main body 4, as shown in FIG. 20. Each third lens face 13 converges the incident monitor light M of each light-emitting element 7 and emits the converged monitor light M towards each light-receiving element 8 corresponding with each third lens face 13.
Still further, as shown in FIG. 20 and FIG. 21, a first recessing section 18 having a substantially trapezoidal vertical cross-sectional shape is formed in a recessing manner on the upper end surface 4a of the lens array main body 4. A sloped surface 18a forming a portion of the inner surface of the first recessing section 18 serves as a total reflection surface 18a. As shown in FIG. 20, the total reflection surface 18a is formed into a sloped surface having a tilt in relation to both the lower end surface 4b and the left end surface 4c of the lens array main body 4 such that the upper end portion thereof is positioned further to the left side in FIG. 20 (in other words, towards a second recessing section 19, described hereafter) than the lower end portion thereof. In addition, as shown in FIG. 21, the planar shape of the total reflection surface 18a is formed into a substantially rectangular shape that is elongated in the array direction of the first lens faces 11 (a vertical direction in FIG. 21). The total reflection surface 18a is disposed on the optical path of the laser light La of each light-emitting element 7 between the first lens faces 11 and a first optical surface 19a of the second recessing section 19, described hereafter.
As shown in FIG. 20, the laser light La of each light-emitting element 7 that has entered each first lens face 11 enters the total reflection surface 18a such as this at an angle of incidence that is the critical angle or greater, from below in FIG. 20. The total reflection surface 18a totally reflects the incident laser light La of each light-emitting element 7 towards the left side in FIG. 20.
The tilt angle of the total reflection surface 18a is 40° to 50° (such as 45°) in the clockwise direction in FIG. 20, with reference to the lower end surface 4b (0°).
In addition, as shown in FIG. 20 and FIG. 21, the second recessing section 19 is formed in a recessing manner on the upper end surface 4a of the lens array main body 4 such as to be positioned on the optical path of the laser light La passing through the first lens faces 11 and the second lens faces 12. As shown in FIG. 20 and FIG. 21, the second recessing section 19 is formed such that the vertical cross-sectional shape is rectangular, and the planar shape is a rectangular shape that is elongated in the array direction of the first lens faces 11.
Here, as shown in FIG. 20, the first optical surface 19a forming a portion of the inner surface of the second recessing section 19 is formed on the right side surface of the second recessing section 19. The first optical surface 19a is formed in parallel with the left end surface 4c of the lens array main body 4.
As shown in FIG. 20, the laser light La of each light-emitting element 7 that has been totally reflected by the total reflection surface 18a perpendicularly enters the first optical surface 19a such as this. The angle of incidence (in other words, a direction of incidence) is an angle (direction of incidence) that is also perpendicular to the left end surface 4c.
In addition, as shown in FIG. 20, a second optical surface 19b is formed on the left side surface of the second recessing section 19 such as to form a portion of the inner surface of the second recessing section 19 and form a portion opposing the first optical surface 19a on the left side in FIG. 20. The second optical surface 19b is also formed in parallel with the left end surface 4c.
As shown in FIG. 20, the laser light La of each light-emitting element 7 that has entered the first optical surface 19a and subsequently advanced toward the second lens face 12 side perpendicularly enters the second optical surface 19b such as this. The second optical surface 19b then perpendicularly transmits the incident laser light La of each light-emitting element 7.
Furthermore, as shown in FIG. 20, a prism 20 having a trapezoidal vertical cross-sectional shape is disposed in a space formed by the second recessing section 19.
Here, as shown in FIG. 20, the prism 20 has a first prism face 20a forming a portion of the surface of the prism 20 in a position facing the first optical surface 19a on the left side in FIG. 20. The first prism face 20a is formed into a sloped surface having a predetermined tilt angle in relation to the lower end surface 4b and the left end surface 4c of the lens array main body 4 such that the upper end portion thereof is positioned further to the right side in FIG. 20 (in other words, towards the first optical surface 19a side) than the lower end portion thereof. As a result, as shown in FIG. 20, a space having a right-triangular vertical cross-sectional shape is formed between the first prism face 20a and the first optical surface 19a.
In addition, as shown in FIG. 20, the prism 20 has a second prism face 20b that forms a portion of the surface of the prism 20 and forms a portion opposing the first prism face 20a. The second prism face 20b is disposed in parallel with the second optical surface 19b in a position facing the second optical surface 19b on the right side in FIG. 20 with a predetermined amount of space therebetween.
Furthermore, as shown in FIG. 20, the prism 20 is positioned in relation to the second recessing section 19 such that a right end surface in FIG. 20 is in contact with a portion extending upwards from the upper end of the first optical surface 19a on the right side surface of the second recessing section 19, a lower end surface in FIG. 20 is in contact with a bottom surface 19e (see FIG. 21) of the second recessing section 19, and a shoulder section 21 formed in the upper end portion is in contact with the upper end surface 4a of the lens array main body 4.
The prism 20 such as this forms the optical path of the laser light La of each light-emitting element 7 that has entered the first optical surface 19a and subsequently advances towards the second lens face 12 side.
Still further, as shown in FIG. 20, a filler material 22 composed of a light-transmissive adhesive material fills the space between the second recessing section 19 and the prism 20. The prism 20 is stably held within the second recessing section 19 by the adhesive force of the filler material 22. In addition, as shown in FIG. 20, the filler material 22 is also disposed on the shoulder section 21, and is used to bond the shoulder section 21 to the upper end surface 4a of the lens array main body 4. A thermosetting resin or an ultraviolet-curable resin can be used as the filler material 22 such as this.
In addition, the filler material 22 is formed having the same refractive index as the prism 20. For example, in some instances, the prism 20 is composed of Ultimo (registered trademark) manufactured by SUBIC Innovative Plastics Holding B.V. as a polyetherimide and the filler material 22 is composed of LumipluS (registered trademark) manufactured by Mitsubishi Gas Chemical Company, Inc. In this instance, the refractive indexes of the prism 20 and the filler material 22 are both 1.64 in relation to light having a wavelength of 850 nm. In addition, for example, in some instances, the prism 20 is composed of ARTON (registered trademark) manufactured by JSR Corporation as a cyclic olefin resin, and the filler material 22 is composed of A1754B manufactured by TECS Co., Ltd. as an ultraviolet(UV)-curable resin. In this instance, the refractive indexes of the prism 20 and the filler material 22 are both 1.50 in relation to light having a wavelength of 850 nm.
Furthermore, as shown in FIG. 20, a reflective/transmissive layer 24 having a thin thickness is formed within the space formed by the second recessing section 19 and in a position on the upstream side in the advancing direction of the laser light La of each light-emitting element 7 in relation to the prism 20. Here, as shown in FIG. 20, the surface of the reflective/transmissive layer 24 on the first optical surface 19a side faces the first optical surface 19a with the filler material 22 therebetween, and the surface on the first prism face 20a side is in contact with the first prism face 20a. In some instances, the reflective/transmissive layer 24 such as this is formed by the first prism face 20a being coated with a single layer film composed of a single metal, such as Ni, Cr, or Al, or a dielectric multilayer film obtained by a plurality of dielectrics having differing dielectric constants (such as TiO2 and SiO2) being alternately stacked. In this instance, a known coating technique, such as Inconel deposition, is used for coating. When coating such as this is used, the reflective/transmissive layer 24 is formed into a very thin thickness of, for example, 1 μm or less. However, in some instances, the reflective/transmissive layer 24 is configured by a glass filter. In addition, the reflective/transmissive layer 24 is formed in parallel with the first prism face 20a.
Here, as shown in FIG. 20, the laser light La of each light-emitting element 7 that has perpendicularly entered the first optical surface 19a advances straight towards the second lens face 12 side on the optical path within the filler material 22 filling the space between the first optical surface 19a and the reflective/transmissive layer 24 without refracting. At this time, when the filler material 22 is formed having the same refractive index as the lens array main body 4 as well, Fresnel reflection at the interface between the first optical surface 19a and the filler material 22 is suppressed. In this instance, the lens array main body 4 maybe composed of the same material as the prism 20. Furthermore, the laser light La of each light-emitting element 7 that has advanced into the filler material 22 between the first optical surface 19a and the reflective/transmissive layer 24 enters the reflective/transmissive layer 24. Then, the reflective/transmissive layer 24 reflects the incident laser light La of each light-emitting element 7 towards the third lens face 13 side at a predetermined reflection factor and transmits the laser light La towards the prism 20 side at a predetermined transmission factor. At this time, because the reflective/transmissive layer 24 has a thin thickness, the refraction of the laser light La transmitted through the reflective/transmissive layer 24 can be ignored (considered to be directly advancing transmission). As the reflection factor and the transmission factor of the reflective/transmissive layer 24, desired values are set based on the material, thickness, and the like of the reflective/transmissive layer 24, to the extent that an amount of monitor light M sufficient for monitoring the output of the laser light La can be obtained. For example, when the reflective/transmissive layer 24 is formed by the above-described single layer film, the reflection factor of the reflective/transmissive layer 24 can be 20% and the transmission factor can be 60% (absorption factor 20%), although depending on the thickness thereof. In addition, for example, when the reflective/transmissive layer 24 is formed by the above-described dielectric multilayer film, the reflection factor of the reflective/transmissive layer 24 can be 10% and the transmission factor can be 90%, although depending on the thickness and the number of layers thereof.
As shown in FIG. 20, during reflection or transmission such as this, the reflective/transmissive layer 24 reflects some (light amounting to the reflection factor) of the laser light La of each light-emitting element 7 that has entered the reflective/transmissive layer 24 as the monitor light M of each light-emitting element 7 corresponding to each light-emitting element 7, towards the third lens face 13 corresponding with each beam of monitor light M.
Furthermore, the monitor light M of each light-emitting element 7 reflected by the reflective/transmissive layer 24 in this way advances within the lens array main body 4 towards the third lens face 13 side, and is emitted from each third lens face 13 towards each light-receiving element 8 corresponding to each third lens face 13.
On the other hand, the laser light La of each light-emitting element 7 transmitted by the reflective/transmissive layer 24 enters the first prism face 20a immediately after transmittance. The direction of incidence of the laser light La of each light-emitting element 7 in relation to the first prism face 20a can be considered to be the same as the direction of incidence of the laser light La of each light-emitting element 7 in relation to the reflective/transmissive layer 24. This is because the reflective/transmissive layer 24 is very thin and the refraction of the laser light La by the layer 24 can be ignored. The laser light La of each light-emitting element 7 that has entered the first prism face 20a advances towards the second lens face 12 side on the optical path within the prism 20.
At this time, because the prism 20 is formed having the same refractive index as the filler material 22, when the laser light La of each light-emitting element 7 enters the first prism face 20a, refraction does not occur in the laser light La. The laser light La of each light-emitting element 7 that has advanced on the optical path within the prism 20 perpendicularly enters the second prism face 20b and is perpendicularly emitted outside of the prism 20 from the second prism face 20b.
Next, the laser light La of each light-emitting element 7 emitted from the second prism face 20b perpendicularly enters the filler material 22 filling the space between the second prism face 20b and the second optical surface 19b. The perpendicularly incident laser light La of each light-emitting element 7 advances straight towards the second lens face 12 side on the optical path within the filler material 22 without refracting. At this time, because the filler material 22 is formed having the same refractive index as the prism 20, Fresnel reflection at the interface between the second prism face 20b and the filler material 22 is suppressed.
The laser light La of each light-emitting element 7 that has advanced within the filler material 22 between the second prism face 20b and the second optical surface 19b in this way is perpendicularly emitted from the filler material 22 and, immediately thereafter, perpendicularly enters the second optical surface 19b, as described above. The laser light La of each light-emitting element 7 that has perpendicularly entered the second optical surface 19b advances towards the second lens face 12 side on the optical path within the lens array main body 4 after the second optical surface 19b, and is then emitted by each second lens face 12 towards the end face of each optical fiber 3 corresponding with each second lens face 12.
As shown in FIG. 21, the second recessing section 19 is formed such that the bottom surface 19e as well as all side surfaces 19a to d of the second recessing section 19 fit within an area indicated by the outer shape of an opening section 19f of the second recessing section 19 when viewed from a surface-normal direction of the upper end surface 4a (above in FIG. 20). In other words, the second recessing section 19 is formed such that the respective projection surfaces in the surface-normal direction of the upper end surface 4a of the bottom surface 19e and all side surfaces 19a to d fit within the area indicated by the outer shape of the opening section 19f. The shape of the second recessing section 19 such as this is a shape enabling detachability from a mold to be ensured. This similarly applies to the above-described first recessing section 18.
In addition, as shown in FIG. 20 to FIG. 23, a pair of fiber-positioning projecting sections 25 are formed such as to be perpendicular to the left end surface 4c, on the left end surface 4c of the lens array main body 4 in positions on both outer sides of the lens formation surface 17a in the array direction of the second lens faces 12, as an optical-fiber positioning structure on the lens array side. The pair of fiber-positioning projecting sections 25 are formed into circular pin shapes (circular columnar shapes) having the same dimensions that project from the left end surface 4c towards the optical fiber 3 side.
On the other hand, as a configuration on the optical fiber 3 side corresponding with the pair of fiber-positioning projecting sections 25, as shown in FIG. 25, a pair of fiber-positioning recessing sections 26 are formed in the optical connector 10, as an optical-fiber positioning structure on the optical fiber side. However, in FIG. 25, because both fiber-positioning recessing sections 26 overlap in the direction perpendicular to the surface of the paper on which FIG. 25 is printed, only one fiber-positioning recessing section 26 towards the front of the paper surface is visible. The pair of fiber-positioning recessing sections 26 are formed into circular boss-hole shapes having the same dimensions such as to satisfy dimensional accuracy adhering to the standards (IEC61754-5, JISC5981) for F12-type multi-core fiber connectors.
As shown in FIG. 25, when the optical fibers 3 are attached to the lens array 1, the corresponding fiber positioning projecting sections 25 are inserted into the fiber positioning recessing sections 26. As a result, positioning of the optical fibers 3 when attaching the optical fibers 3 to the lens array 1 is performed.
Furthermore, as shown in FIG. 23, a pair of device-positioning recessing sections 28 are formed on the lower end surface 4b of the lens array main body 4 in positions on both outer sides of the lens formation surface 16a in the array direction of the first lens faces 11 and the third lens faces 13, as a photovoltaic-device positioning structure on the lens array side. The pair of device-positioning recessing sections 28 are formed into circular boss-hole shapes having the same dimensions, and the center axes thereof are formed in parallel with the optical axis OA(1) of the first lens faces 11.
On the other hand, as a configuration on the photovoltaic device 2 side corresponding with the pair of device-positioning recessing sections 28, as shown in FIG. 25, a pair of device-positioning projecting sections 29 are formed in the semiconductor substrate 5, as the photovoltaic-device positioning structure on the photovoltaic device side. However, in FIG. 25, because both device-positioning recessing sections 29 overlap in the direction perpendicular to the surface of the paper on which FIG. 25 is printed, only one device-positioning recessing section 29 towards the front of the paper surface is visible. The pair of device-positioning projecting sections 29 are formed into circular pin shapes having the same dimensions that extend in a direction parallel to the center axis of the outgoing light from the light-emitting elements 7.
As shown in FIG. 25, when the photovoltaic device 2 is attached to the lens array 1, each device-positioning projecting section 29 is inserted into the corresponding device-positioning recessing section 28. As a result, positioning of the photovoltaic device 2 when attaching the photovoltaic device 2 to the lens array 1 is performed.
(Bidirectional Communication-Supporting Lens Array)
Next, FIG. 26 is a vertical cross-sectional view of a bidirectional communication-supporting lens array 31, together with the photovoltaic device 2 and the optical fibers 3. In addition, FIG. 27 is a planar view of the lens array 31 shown in FIG. 26. FIG. 28 is a left-side view of the lens array 31 shown in FIG. 26. FIG. 29 is a bottom view of the lens array 31 shown in FIG. 26.
In the bidirectional communication-supporting lens array 31, the configurations and functions of the first lens faces 11, the second lens faces 12, and the first recessing section 18 are similar to those of above-described light monitoring-supporting lens array 1.
On the other hand, instead of each constituent section 20, 22, and 24 that obtains the above-described monitor light M, the bidirectional communication-supporting lens array 31 includes a configuration for supporting reception of optical signals.
In addition, a configuration supporting reception of optical signals is included on the photovoltaic device 2 side and the optical fiber 3 side as well.
In other words, as shown in FIG. 26, reception-dedicated second optical fibers 33 are arranged in parallel near the optical fibers 3 in the optical connector 10 (near the lower side in FIG. 26). The second optical fibers 33 are arrayed along the same direction as the array direction of the optical fibers 3 at the same pitch as the optical fibers 3. The number of second optical fibers 33 is also the same as the number of the optical fibers 3 (12 optical fibers). In addition, the number of second optical fibers 33 is the same as the number of light-receiving elements 8 and the number of third lens faces 13. Laser light LR is emitted from each end face 33a of the plurality of second optical fibers 33 facing the lens array 31, towards the lens array 31. The laser light LR is equivalent to optical signals for reception.
In addition, as shown in FIG. 26, fourth lens faces 14 are formed in positions adjacent to the second lens faces 12 in a direction perpendicular to the array direction of the second lens faces 12 (downward direction in FIG. 26) on the left end surface 4c of the lens array main body 4, in positions facing the end faces 33a of the second optical fibers 33, each fourth lens face 14 into which the laser light LR emitted from each second optical fiber 33 enters. The number of fourth lens faces 14 is the same as the number of second optical fibers 33. These plurality of fourth lens faces 14 are formed having a circular planar shape with the same dimensions as one another, and are formed in an array along the array direction of the second lens faces 12 at the same pitch as the second lens faces 12. In addition, an optical axis OA(4) of each fourth lens faces 14 is formed perpendicular to the left end surface 4c. The fourth lens faces 14 may have the same dimensions as the second lens faces 12.
Furthermore, as shown in FIG. 26, the second recessing section 19 has a second total reflection surface 34 that forms a portion in a predetermined area on the right end portion side on the bottom surface of the second recessing section 19. The second total reflection surface 34 is formed into a sloped surface such that the upper end portion thereof is positioned further to the left side in FIG. 26 than the lower end portion thereof. The second total reflection surface 34 maybe formed in parallel with the total reflection surface 18a of the first recessing section 18. The laser light LR of each second optical fiber 33 that has entered each fourth lens face 14 enters the second total reflection surface 34 such as this at an angle of incidence that the critical angle or greater from the left side in FIG. 26. The second total reflection surface 34 totally reflects the incident laser light LR of each second optical fiber 33 towards the third lens face 13 side (downward in FIG. 26).
The laser light LR of each second optical fiber 33 that has been totally reflected by the second total reflection surface 34 in this way is converged by each third lens face 13 and emitted towards the corresponding light-receiving elements 8. In other words, in the bidirectional communication-supporting lens array 31, the third lens faces 13 are used to collect reception optical signals instead collecting the monitor light M, and the light-receiving elements 8 are used to receive the reception optical signals instead of receiving the monitor light M.
On the other hand, in a manner similar to that in the light monitoring-supporting lens array 1, laser light LT of each light-emitting element 7 passes through the first lens faces 11, the total reflection surface 18a, the first optical surface 19a, and the second optical surface 19b in sequence, and is then emitted from each second lens face 12 towards the corresponding end face 3a of the optical fiber 3.
Ina configuration such as this, the laser light LR emitted from each second optical fiber 33 can be coupled with each light-receiving element 8 through the fourth lens faces 14, the second total reflection surface 34, and the third lens faces 13. Therefore, bidirectional communication can be effectively supported.
In the bidirectional communication-supporting lens array 31 such as this, for example, when a configuration separate from the lens array main body 4, such as a coating of reflective film (such as Au, Ag, or AL) on the total reflection surfaces 18a and 34, is not provided, the lens array 31 is the lens array main body 4 itself.
As conventional technology related to lens arrays such as this, proposals such as that in Patent Literature 1 has been made in the past    Patent Literature 1: Japanese Patent Application No. 2010-242124

Lens array and manufacturing method thereof


A low-voltage to high-voltage level shifter circuit includes an input circuit, a voltage shifting circuit, and an output circuit. The input circuit is configured to receive an input signal having a voltage range between a first voltage and a ground voltage, and to provide an inverted input signal and a delayed version of the inverted input signal. The voltage shifting circuit is coupled to the input circuit and is configured to receive the input signal, the inverted input signal, and the delayed version of the inverted input signal. The voltage shifting circuit is configured to provide an internal signal having a voltage range between a second voltage and the ground voltage, the second voltage being higher than the first voltage. The output circuit provides an output voltage in the high-voltage range for the corresponding input voltage in the low-voltage range.

The present invention relates to the field of electronic circuit technology; in particular it relates to a low-voltage to high-voltage level shifter circuit.
To achieve high performance and high integration density, transistor dimensions are aggressively scaled down in the ultra-deep submicron process and nanometer process, while low power dissipation is achieved by scaling down the supply voltage even under 0.7 V or 0.9V. In various electronic devices, integrated circuits operating at low supply voltages are interfaced with electronic circuits operating at higher supply voltages. For example, a chip set operating at a first core voltage level (VDDL) can interface with a memory device operating at a higher voltage level (VDDH), for example, at 1.4 V. In addition, many kinds of I/O voltages such as 1.5V, 1.8V, 2.5V and 3.3V are needed in the I/O interface part.
A conventional voltage converter circuit is often used as a bridge for connecting low-voltage circuits and high-voltage circuits. For example, a voltage shifter circuit can be used to connect a low-voltage core logic to a high-voltage I/O interface circuit to obtain a higher drive current.
FIG. 1 is a circuit diagram of a conventional voltage shifter circuit. As shown in FIG. 1, the voltage converter circuit includes transistors M101, M102, M103, M104, M105, and M106, in which transistors M101 and M102 may be thin gate oxide transistors, and transistor M103 and M104 may be thick gate oxide transistors.
As shown in FIG. 1, the current driving capability of transistors M105 and M106 are affected by the threshold voltage of each transistors, and they are not affected by the high-voltage power supply VDDH. In this way, a stable current driving capability can be maintained, suitable for a wide range of high-voltage power supply VDDH.
However, the inventor has observed that, in FIG. 1, when input IN is high, transistors M103 and M105 are open simultaneously, thus forming a path from the power supply to ground leakage current path. Since the transistors M103 and M104 are thick gate-oxide transistors having high threshold voltages, a conventional low-voltage to high-voltage shifter circuit, such as the one shown in FIG. 1, cannot be applied to ultra-low input signal voltages.
FIG. 2 is a circuit diagram of another conventional low-voltage to high-voltage shifter circuit. As shown in FIG. 2, the voltage converter circuit includes transistors M201, M202, M203, M204, M205, and M206, in which transistors M201 and M202 are thin gate oxide transistors, and transistors M203 to M206 are thick gate oxide transistors. In the low-voltage to high-voltage shifter circuit in FIG. 2, thick gate-oxide PMOS transistors M207 and M208, along with thick gate oxide NMOS transistors M203 and M204, form an inverter and can quickly cut off the leakage current from the power supply to ground to improve the operating frequency.
However, the inventor has observed that the addition of thick gate-oxide MOS transistors M207 and M208 increases the minimum required power supply voltage VDDH. As a result, the low-voltage to high-voltage shifter circuit shown in FIG. 2 is not suited for wide output voltage applications.
In the meanwhile, with the enhancement of system performance, high speed becomes increasingly important. The inventor has also observed that conventional level shifter circuits often fail to meet the high speed requirements.
Therefore, an improved design of the low-voltage to high-voltage shifter circuit is highly desirable.

Low-voltage to high-voltage level shifter circuit

Semiconductor Manufacturing International (Shanghai) Corporation


A reconfigurable computing device includes a reconfigurable logical device of which a circuit logic can be changed based on configuration data, a storage part to store beforehand input-output attributes of input-output parts of the reconfigurable logical device, and a verification part to verify the configuration data by making a comparison between information on the input-output parts in the configuration data and the input-output attributes stored in the storage part. With this, it is possible to inspect the configuration data of the reconfigurable logical device by a simple method.

1. Field of the Invention
The present invention relates to a reconfigurable logical device, and in particular it relates to a technique of inspecting configuration data of the reconfigurable logical device.
2. Description of the Related Art
In a device (reconfigurable logical device), such as an FPGA (Field Programmable Gate Array) of which a circuit logic can be changed based on configuration data (circuit information data), the configuration data, if not correct, will be a cause that damages the device. For example, when both pads (pins), which are input-output parts of an FPGA chip, and a peripheral circuit, which is connected thereto, are in output states, there will be a high probability that the device will be damaged.
An FPGA can be used for the purpose of changing and/or updating the function of a product by causing its configuration data to be downloaded after the shipment thereof. For example, with an in-vehicle device using an FPGA, the function thereof can be changed by downloading its configuration data via a wireless network or a recorded storage medium from the outside of a vehicle. At the time when such configuration data is downloaded, an alteration or falsification by a third party will pose a problem. It is considered that with an intention to destroy the device, a third party may alter or falsify the configuration data so as to place both the pads of the FPGA and its peripheral circuit into their output states, as mentioned above.
In order to verify the alteration of the configuration data by such a third party, there have been proposed methods that make use of encryption technology (Japanese patent application laid open No. 2003-122442, and Japanese patent application laid-open No. 2003-304235). In these methods, the detection of an alteration of configuration data is made possible by applying an electronic signature to the configuration data by the use of encryption technology.
However, the methods of verifying configuration data using an electronic signature are carried out on a large scale, and will cause an increase in cost, etc.
An object of the present invention is to provide a technique that is capable of inspecting the configuration data of a reconfigurable logical device by the use of a simple method.

Reconfigurable computing device and method for inspecting configuration data


The purpose of the present invention is to reduce a load of preventing dew condensation, and to provide a highly reliable humidity detection device. In order to achieve the purpose, this humidity detection device is provided with: a humidity sensor having a humidity detection unit and a temperature detection unit; a heating resistor that heats the humidity sensor; and a heating control unit that controls a heating temperature of the heating resistor. The humidity detection device is characterized in having a target temperature storage unit that stores target temperatures of the heating resistor, said target temperatures having been determined corresponding to temperatures and humidities.

Conventionally, automobiles using electronic control fuel injection systems have been widely used. In engine compartments of such automobiles, various sensors and control devices are disposed. As one of them, there is a humidity detector. Although humidity detectors have recently come into use for the purpose of fuel control, humidity detectors have conventionally been used mainly for air conditioning management in automobile cabins. When humidity detectors are used in automobile cabins, there is no requirement for durability or the like which presupposes a severe environment. For example, when a humidity detector is used integrally with the intake air flow measuring device or other sensors for the purpose of controlling an engine, the humidity detector is required to have environment-resistant performance equivalent to that of the intake air flow measuring device.
An environment particularly unfavorable to the humidity detector is adhesion of water droplets to a humidity detecting unit which originates from dew condensation of a detecting element unit, or the like. When moisture in air reaches a saturation point (relative humidity 100%), dew condensation occurs. A temperature at which dew condensation occurs is called a dew point. When dew condensation occurs on a humidity sensor, a significant delay is generated in detection responsiveness to changes in humidity and humidity measurement accuracy itself is negatively affected. In addition, there may be a case where the humidity detector loses a function thereof. When dew condensation occurs on the humidity detecting unit, a signal value indicating maximum or minimum humidity is output, and the humidity detector temporarily loses the function as a humidity detector until the detecting element unit dries. As a result, an engine control system is negatively affected while the function of the humidity detector is lost. This is a salient problem particularly when a polymer capacitance humidity sensor is used in an environment where an atmosphere rapidly changes such as inside of a vehicle intake pipe. A clear technical object is necessary to deal with the above problems.
PTL 1 is an example of a humidity detector including a countermeasure against dew condensation described above. PTL 1 discloses that dew condensation on a humidity detecting unit is prevented by obtaining a dew point temperature, and then heating, by a heating unit included therein, the humidity detecting unit to a temperature at which there is a certain difference between a sensor temperature and the dew point temperature.


An electrical device cabinet includes a cabinet body, a front panel, and a positioning mechanism. The cabinet body has an open front end. The front panel is formed by a resin molding, and is mounted to the front end of the cabinet body. The positioning mechanism includes a concave portion disposed at the cabinet body and a convex portion disposed at an inner face of the front panel. The positioning mechanism positions the front panel in a lateral direction with respect to the cabinet body by mating the concave portion and the convex portion. The convex portion is formed in a hollow shape and is covered by an outer face of the front panel from a front side of the front panel.

1. Field of the Invention
The present invention generally relates to an electrical device cabinet. More specifically, the present invention relates to an electrical device cabinet having a front panel which is a resin molding.
2. Background Information
FIG. 5 is a simplified vertical cross sectional side view of a front panel 105 employed in a known electrical device cabinet. The front panel 105 is equipped with a convex portion 106 used for positioning the front panel 105 in a lateral direction of the electrical device cabinet. The convex portion 106 is provided at a location in a lateral direction of a bottom plate 155 of the front panel 105. The convex portion 106 is solidly formed by increasing a thickness of the bottom plate 155 at the location.
FIG. 6 is a simplified vertical cross sectional side view of another convex portion 116 formed on the front panel 105 employed in another electrical device cabinet. A recess 161 is formed on a lower face side of the bottom plate 155 of the front panel 105 at the location where the convex portion 116 is formed.
A configuration in which an electrical device cabinet is made up of a chassis, a top cover, and a front panel is known (see Japanese Laid-Open Patent Application No. 2002-217556 and Japanese Laid-Open Patent Application No. 2005-136040, for example). The coupling of a front panel and a chassis with an engagement structure is also known (see Japanese Laid-Open Patent Application No. 2002-324982, for example). Furthermore, research into setting a vertical attachment reference place for a front panel with respect to a front panel attachment frame is known (see Japanese Laid-Open Patent Application No. H6-89559, for example).
However, when the convex portion 106 is formed in the way illustrated in FIG. 5, a tiny depression known as a "sink mark" is produced on a lower face 156 of the bottom plate 155 at the location where the convex portion 106 is formed because of shrinkage of the resin molding material. The sink mark becomes a very noticeable flaw in the appearance of the electrical device cabinet.
The occurrence of the above-mentioned sink mark is suppressed if the convex portion 116 is formed in the way illustrated in FIG. 6. Specifically, an increase in the thickness of the front panel 105 at the location of the convex portion 116 is avoided by forming the recess 161. However, since the recess 161 is exposed on an outer face (the lower face) of the front panel 105, the recess 161 becomes a very noticeable flaw in the appearance of the front panel 105 of the electrical device cabinet.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved electrical device cabinet that prevents flaws in its outer appearance. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.


A container and method of forming intimately bonded plastic components including a lower base with a closed bottom and an upstanding peripheral wall, and an upwardly extending ring telescopically engaged with the base and extending from a lower edge at an intermediate height on said base wall to an upper edge vertically spaced above the base wall to define three distinct zones along the height of the container.

The present invention broadly relates to molded plastic containers formed in multiple layers of appropriate synthetic resinous materials.
While such containers are generally known, as will be seen in U.S. Pat. No. 3,309,448, issued Mar. 14, 1967, such known containers basically comprise duplicate layers coextensive with each other with each layer in itself being of a full receptacle configuration. In the container described in U.S. Pat. No. 3,309,448, the purpose of the multiple layers is to provide for a two-tone appearance.
In another known form of multiple layer container, the first receptacle defining component will have a second receptacle defining component enclosing only the lower portion of the first receptacle component, thus providing a particular aesthetic appearance involving lower and upper zones.
As will be seen, for example in U.S. Pat. No. 3,914,081, the bowl and ring portions of the serving bowl could be formed together in one injection molding apparatus. The apparatus described in U.S. Pat. No. 3,914,081, which is expressly incorporated herein by reference in its entirety herein, discloses a machine that would allow for two step injection molding of ring and base portions of a container in accordance with the present invention.

Multiple component container and method of molding same


A method of and apparatus for identifying the presence of thin photocatalytic (PCAT) coatings on glass surfaces. An apparatus is disclosed that can determine whether a PCAT coating (which may comprise titanium dioxide, for example) having a thickness of less than about 100 Å is present on the surface of a substrate such as glass. The apparatus may measure the reflectance of electromagnetic energy (such as light energy) at the surface of a substrate using energy at selected wavelengths or wavelength ranges. The apparatus may determine reflectance values for PCAT coated surfaces of any thickness, as well as for uncoated surfaces.

A great deal of work has been done with the goal of developing self-cleaning coatings for windows and other substrates. One area of research has focused on photocatalytic coatings. Research in this area is founded on the ability of photocatalytic coatings to break down organic materials that come into contact with the coatings. One such photocatalyst appears to be titanium oxides (titanium dioxide, for example).
Windows may derive great benefit from photocatalytic coatings. For example, such windows may have self-cleaning characteristics. To the extent organic matter is deposited on such a window, the photoactive coating may act to oxidize the organic deposits, thereby having a cleaning effect on the surface of the window. To the extent residue survives this photocatalysis, such residue may be more easily removed by washing or, for outdoor window surfaces, by run-off rainwater.
Photocatalytic coatings have been developed which typically involve a titanium dioxide layer on a glass pane. The coatings are commonly provided with a relatively thick layer of titanium dioxide and/or a specific under-layer system designed for achieving high levels of photoactivity. Such photocatalytic coatings may be useful for absorbing ultraviolet radiation and photocatalytically degrading organic materials that may have collected on the coating. Thick titanium dioxide layers, unfortunately, produce high levels of visible reflectance, thus creating a somewhat mirror-like appearance. This high visible reflectance tends to exaggerate the appearance of dirt on a window.
Glass surfaces, such as windows, may have a photocatalytic (PCAT) coating applied in which the coating typically comprises a layer of titanium dioxide (TiO2) that may be roughly 250 to 300 angstroms (Å) thick. PCAT coatings in this thickness range may be visible to the unaided human eye, and their presence may therefore be relatively easy to detect. Furthermore, at coating thicknesses in this range, visible light reflectance is significantly higher than it would be for the same substrate without the PCAT coating (typically in the range of 7 to 10% higher). Devices have been developed that can help distinguish between PCAT coated surfaces at these coating thicknesses and non-coated surfaces.
More recently, PCAT coatings have been developed in which the coating is significantly thinner than that described above. For example, work has been done to reduce the thickness of the TiO2 layer in certain PCAT coated products to reduce and possibly eliminate reflectance and appearance differences between coated and non-coated surfaces, while maintaining the photocatalytic functionality of the coating.
The existence of thinner PCAT coatings may make it more difficult to distinguish between substrates coated with a "thin" PCAT coating and uncoated substrates. Visible differences between "thin" PCAT coatings and uncoated surfaces may be negligible. Furthermore, existing devices, which may have been designed for use with "thick" PCAT coatings (i.e., 250 to 300 Å), may not be able to distinguish surfaces with "thin" PCAT coatings from uncoated surfaces. These difficulties may pose additional challenges in the areas of manufacturing, quality assurance and distribution. For example, a customer or distributor receiving a shipment of the thin PCAT coated product may not be able to easily verify that they received the correct product due to the reduction in appearance and reflectance differences. New methods and devices for identifying the presence of "thin" PCAT coated products are therefore necessary.

Method and apparatus for identifying photocatalytic coatings


A locking grating or seal for a conduit includes a cover positioned at one open end of the conduit and is removably engaged and axially aligned with, an expander positioned within the conduit. A jacking bolt penetrates the cover and the expander, and is threadedly engaged with a jacking nut in a position within the conduit and spaced apart from the expander. C-shaped elastically flexible arms are integrally engaged with the expander and with the jacking nut so that rotation of the jacking bolt enables the jacking nut to move toward the expander forcing the C-shaped arms to bow outwardly into contact with the conduit for gripping it.

This disclosure relates to the field of drains for liquid flows, and more particularly to a removable floor drain grating having a mechanism for locking the grating in place over a drain pipe and which is unlocked only by use of a tool so as to prevent casual removal of the grating which may lead to undesired clogging due to drain pipe stuffing, that is, allowing large amounts of materials to enter the drain pipe. The same locking mechanism may be used with a cover for sealing the open end of a drain pipe or any similar pipe when the grating is replaced with a cover plate without any pass-through apertures, i.e., without openings therein.
A drain grating or covering is conceived as a plate that may be fitted over a drain pipe or conduit, and which may have plural openings in it, each generally smaller than the span of the drain pipe itself. Its purpose is to prevent large items from entering the drain pipe which may clog it. A grate may also be constructed as a series of spaced apart rigid bars as a lattice or as a screen such as one made of expanded metal sheeting or the like. In general, a drain grate is a filter. Drain grates usually become covered or engaged with the large items which they are designed to prevent from entering the drain pipe so that they must be periodically cleared which may require temporary removal from the drain pipe. In commercial kitchens, floors are generally hosed down to assure meeting cleanliness standards. Items such as foodstuffs, packaging materials, and the like are carried by water flows to floor drains and if allowed to enter the drain pipes, clogs may occur. To prevent this, such items must be removed from the drain grate manually in order to have a free flow of water. Kitchen help may resort to removing a drain grate in order to allow such items to enter the drain pipe thereby shortening kitchen cleanup time. This practice often results in drain pipe clogging requiring expensive steps in clearing such clogs. To help prevent this, a locking drain pipe grating may be used; one that is not easily removed. The prior art discloses various means for locking a cover onto a drain or other cylindrical conduit including types described in the following. As said, such locking mechanisms are equally useful in sealing a cover plate onto the end of a pipe to prevent anything from passing into or out of the pipe.
The prior art discloses a ratchet type closet flange for replacing broken cast iron closet flanges in old buildings or in new construction in place of conventional cast iron closet flanges. Such a device includes a flange body, a cup, a rubber seal, and a means for applying pressure such as a central bolt. After removing the broken closet flange, the ratchet type closet flange is inserted into the existing pipe. A compression seal is formed between the flange body and the inside of the pipe by applying pressure to the flange body and the cup using a central bolt, thereby forcing a compression relationship between the rubber seal and the pipe. The ratchet type closet flange may slide up and down inside the pipe to achieve a desired height.
The prior art also discloses various drain covers with looking mechanisms including those having a cylindrical body with a peripheral sidewall. Wedge members are movable from a release position to a locking position by use of a central screw or jacking mechanism. In the release position each wedge member is positioned at one end of the peripheral sidewall. In the locking position each wedge member is moved upwardly into contact with an opposing end of the peripheral sidewall so that an exterior surface of the peripheral sidewall wedges within the cylindrical body.
The presently described apparatus incorporates an advance over prior art concepts providing a locking grating or sealing cover with novel benefits in manufacture and operation as will be described below.


An apparatus for digital signature authentication includes a dividing unit that divides streaming data into plural pieces of partial data in a predetermined unit; a first creating unit that creates a hash value string including plural hash values corresponding to the pieces of partial data; a second creating unit that creates a first binary tree using the hash value string; and a third creating unit that creates a digital signature of a signer using a root value of the first binary tree.

1. Field of the Invention
The present invention relates to a technology for digital signature authentication.
2. Description of the Related Art
It has become a common practice to install a security camera in shops, downtown areas, and apartments, or to install a drive recorder in commercial vehicles. Accordingly, moving images are increasingly used as an evidential matter. Moreover, it has also become common to keep a record of conversation between a customer and an operator to deal with troubles in telephone transactions or in a customer support operation.
Currently, when a moving image or audio data is used as an evident, a video tape, an image, or an audio file is provided as it is. However, if stored images and audio data are digitized, it becomes easy to tamper or edit such data. Therefore, third-party authentication such as a signature and a timestamp becomes necessary. A service and a product to record sound of a telephone operator are actually provided, and needs for such a technology are expected to increase.
On the other hand, protection of privacy is another problem for increasing security cameras in using a shot image, and is discussed. In addition, since Private Information Protection Law is enforced, use of private information of an individual has been strictly limited and disclosure or partial deletion of information is required if the individual requests.
To protect privacy while maintaining adequacy as an evidential matter, a signature technology is studied in which partial guaranteeing of an original content is enabled that guarantees a part of an electronic document to maintain its original content, and in which concealment of a part of the electronic document is enabled. A signature technique in which addition, alteration, concealment (sanitization), and deletion are enabled on a part of a document to which a digital signature is applied while guaranteeing that the document maintains its original content is disclosed in the third Forum of Information Technology FIT 2004, M-066, 2004, "Proposal of a Partial Integrity Assurance Technology Considering Correction and Circulation of Electronic Documents" by Takashi Yoshioka and Masahiko Takenaka, and in Japanese Patent Laid-Open Publication No. 2006-60722.
By using such a technique, signature verification of a digital-signed electronic document becomes possible even in a state where a part of the document is concealed. Furthermore, it is possible to verify that no change has been made in the document except a concealed part (also "altered part" or "added part" in the technique disclosed in "Proposal of a Partial Integrity Assurance Technology Considering Correction and Circulation of Electronic Documents") by a third party.
The signature technique disclosed in "Proposal of a Partial Integrity Assurance Technology Considering Correction and Circulation of Electronic Documents" is explained. This signature technique is a partial integrity assurance technology called PIAT, and partial integrity assurance of electronic data being a subject of signature is performed in a trilateral model of a signer, an extractor, and a verifier.
The signer is a person that digitally signs electronic data being a subject of signature, or a computer that is operated by the person. The signer guarantees a content of the electronic data by signing the data. It is necessary to sign the data under such a condition that which part is to be extracted from the subject of signature is unpredictable.
The extractor is a person that extracts (conceals or alters) a part from the electronic data being a subject of signature, or a computer that is operated by the person. The extractor extracts a part of the electronic data digitally signed by the signer and discloses the extracted part to the verifier. The extracted electronic data is referred to as extraction data. There are two kinds of extracting methods, onymous extraction and anonymous extraction. In the anonymous extraction, the extractor performs an extracting process under anonymity. In the onymous extraction, the extractor discloses information on the extractor so that who has performed the extracting process is specified.
The verifier is a person that verifies whether the extraction data is guaranteed by the signer, or a computer that is operated by the person. In the case of the anonymous extraction, it is verified whether the extraction data is a part of the electronic data signed by the signer. In the case of the onymous extraction, it is verified whether the extracting process is performed by the extractor as well as whether the extraction data is a part of the electronic data signed by the signer.
FIG. 22 is a schematic diagram showing an outline of algorism for a signer in PIAT. The signer divides an electronic document (entire character string) 2200 into partial data (character strings of respective lines), and calculates a hash value of each partial data to create a hash value set 2201. The digital signature of the signer is given to the hash value set 2201. A combination of the hash value set 2201 and a digital signature 2202 of the signer is a PIAT signature 2203 of the signer.
FIG. 23 is a schematic diagram showing an outline of algorism for an extractor in PIAT. The extractor extracts partial data (extraction data 2300) from the data to which the PIAT signature is given by the signer. Thereafter, the extractor performs the same operation as that performed by the signer. A combination of a hash value set 2301 thus obtained and a digital signature 2302 of the extractor is a PIAT signature 2303 of the extractor. When a deleted part is wished to be specified, a concealing process is performed, and partial data after deletion is modified to partial data, such as "XXXXXXX", that can be identified as concealment.
FIG. 24 is a schematic diagram showing an outline of algorism for a verifier in PIAT. The verifier first verifies integrity of the hash value sets 2201 and 2301 from the PIAT signatures of the signer and the extractor. The verifier then creates a hash value set 2301 from the disclosed extraction data 2300, and verifies whether the hash value set 2301 thus created and the hash value set 2301 included in the PIAT signature 2303 of the extractor coincide with each other.
Finally, the verifier compares the hash value set 2201 of the signer and the hash value set 2301 of the extractor. It is found that a position of data at which the hash value is identical in both of the hash value sets 2201 and 2301 is a position of data extracted from the electronic document. If the hash value set 2301 of the extraction data 2300 is not included in the hash value set 2201 of the PIAT signature 2203 of the signer, it is determined that the extraction data 2300 is tampered.
In PIAT, extraction is performed basically by the onymous extraction, and therefore, it is possible to verify who has extracted which part. However, in the case of the anonymous extraction, the PIAT signature process performed by the extractor can be omitted. In this case, the verifier performs verification of the hash value set in the PIAT signature of the signer and the digital signature thereof, creation of a hash value set from the disclosed extraction data, and comparison with the hash value set in the PIAT signature of the signer.
This signature technique (PIAT) can be applied also to streaming data including a moving image file such as moving picture experts group phase 1 (MPEG-1) and an audio file.
In this case, streaming data being a subject of signature is divided into partial data. When streaming data of MPEG-1 is divided into partial data so as to be extractable, the data can be divided in an image unit or in a group of picture (GOP) unit.
However, in MPEG-1, since an interframe prediction technology is applied, P-frame and B-frame lack independency in an image unit. Therefore, extraction is considered to be limited. On the other hand, GOP is a smallest unit of a moving image in which several images are combined, and independent reproduction in this unit is possible. GOP is a structure for reproducing or editing a moving image from a middle of data. For simplicity, it is assumed that division into partial data is performed in the GOP unit.
The signer divides a moving image (for example, an MPEG-1 file) being a subject of signature in GOP units, and calculates a hash value of each GOP to create a hash value set. The signer then gives a digital signature of the signer to the created hash value set, to create a PIAT signature by combining the hash value set and the digital signature.
The extractor extracts a required partial moving image from the moving image to which the PIAT signature is given by the signer. In the case of the anonymous extraction, the extractor discloses the extracted moving image and the PIAT signature of the signer. In the case of the onymous extraction, the extractor performs the same operation as that performed by the signer, to create a PIAT signature of the extractor, and discloses the extracted moving image, the PIAT signature of the signer, and the PIAT signature of the extractor.
In the case of the onymous extraction, the verifier first verifies integrity of the hash value set from the PIAT signature of the signer and the PIAT signature of the extractor. The verifier then creates a hash value set from the disclosed extracted moving image, and verifies that the hash value set thus created coincides with the hash value set included in the PIAT signature of the extractor.
Finally, the verifier compares the hash value set of the signer and the hash value set of the extractor. It is found that a position of data at which the hash value is identical in both of the hash value sets is a position of data extracted from the moving image being the subject of signature. In the case of the anonymous extraction, the verifier performs verification of the hash value set in the PIAT signature of the signer and the digital signature thereof, creation of a hash value set from the disclosed extracted moving image, and comparison with the hash value set in the PIAT signature of the signer, to check whether it is partial information.
Next, the signature technique disclosed in Japanese Patent Laid-Open Publication No. 2006-60722 is explained. In this signature technique, an amount of data related to signature can be reduced by managing hash values, which are a part of the data related to signature, in a binary tree, and data to be a subject of signature includes not only electronic documents but also streaming data such as a moving image and audio data, similarly to PIAT described above. Herein, an example in which the subject of signature is streaming data of a moving image is explained.
FIG. 25 is a schematic diagram for explaining a signing process performed by a signer in the signature technique disclosed in Japanese Patent Laid-Open Publication No. 2006-60722 in which streaming data of a moving image is the subject of signature. In this technique, hash values h1 to h5 of partial moving images f1 to f5 obtained by dividing a moving image file F being a subject of the signature by GOP units are managed in a complete binary tree. This requires addition of dummy data D.
The signer first adds the dummy data D at the end of the moving image file F, and calculates hash values h1 to h8 for each GOP as a process of the first level. As a process of the second level, the signer then connects the end of a hash value hx and the head of hy to calculate a new hash value hx,y. The hash value hx and the hash value hy are adjacent values.
The same process is repeated in the third level and later until a single hash value is obtained. Thus, a hash-value binary tree T is created. The single hash value is referred to as root Ra. In the example shown in FIG. 25, the root Ra is obtained in the fourth level. The signer gives a digital signature Sa of the signer to the root Ra.
Disclosure information A that is stored at this time includes the original moving image file F, the dummy data D (or a root hash value string {h6, h7,8} having hash values of the partial moving images f6 to f8 of the dummy data D as leaves), and the root Ra to which the digital signature Sa is given.
FIG. 26 is a schematic diagram for explaining an extracting process performed by an extractor in the signature technique disclosed in Japanese Patent Laid-Open Publication No. 2006-60722 in which streaming data of a moving image is the subject of signature. The extractor extracts the partial moving images f3 and f4 from the moving image file F being a subject of signature, and calculates the hash values h1 to h8 of the partial moving images f1 to f8 of the moving image file F and the dummy data D as a process of the first level. The extractor then deletes all partial moving images f1, f2, and f5 to f8 except the extracted partial moving images f3 and f4.
Thereafter, the extractor connects the end of the hash value hx and the head of the hash value hy to create a new hash value hx,y, and repeats the same process in the second level and later until a single hash value is obtained. Thus, the hash-value binary tree T is created. In the example shown in FIG. 26, a root Rb is created with the hash value obtained in the fourth level. The extractor gives a digital signature Sb of the extractor to the root Rb.
Signature related data B disclosed at this time includes the extracted moving images f3 and f4, root hash values h1,2 and h5,8 that are obtained from the hash values of the deleted partial moving images f1, f2, and f5 to f8, and the root Rb to which the digital signature Sb is given.
However, in the signature technique described above, when a part of large streaming data such as a moving image file and an audio file is extracted, it is necessary to store all of hash values of moving images other than the extracted moving image. Therefore, an amount of data related to signature is enormous.
Moreover, in the signature technique disclosed in Japanese Patent Laid-Open Publication No. 2006-60722, although it is possible to reduce an amount of data related to signature by managing hash values, which are a part of the data related to signature, in a binary tree, addition of dummy data is required to manage the hash values in a complete binary tree.
Accordingly, an amount of data to be stored increases due to added dummy data D (the dummy data D or a hash value group of a hash tree T constituted only of the dummy data D).
Furthermore, since the dummy data D is added, calculation of hash values therefor is required, and as a result, a processing time also increases. In addition, falsification (curtailment) of the moving image file being the subject of signature is possible by replacing data at the end of the moving image file with the dummy data.
Moreover, random numbers that are included in the signature related data required to guarantee uniqueness of the extracted partial moving images f3 and f4 are also required to be stored as they are. FIG. 27 is a schematic diagram for showing random numbers that are added to the partial moving images f1 to f5. As shown in FIG. 27, although it is possible to unify the hash values h1 to h5 of the respective partial moving images f1 to f5 in units of GOP into a single hash value h, the same number of random numbers r1 to r5 as the number of the partial moving images f1 to f5 are required. As a result, an amount of the signature related data becomes enormous.
As described above, if PIAT is simply applied to streaming data such as a moving image file, even if a part of the data is extracted, the data can be guaranteed as a part of the moving image file being the subject of signature.
However, as described above, when the moving image file being the subject of signature is a moving image file with a long recording time or a moving image file having a high frame rate, the number of frames or GOP becomes large. As a result, an amount of data of a hash value set included in the PIAT signature increases.
Furthermore, when a content of the moving image file being the subject of signature is an animation, the same frame or GOP appears repeatedly. In PIAT, if the same image appears in partial data, a moving image corresponding to the deleted part can be restored based on a hash value set. To guarantee uniqueness of the partial data, if the same image appears in the partial data, a random number is required to be added for each of original partial data.
FIG. 28 is a schematic diagram showing a moving image file of an animation. As shown in FIG. 28, even if images E1 and E2 are deleted, when the hash values h1 to h3 of images E1 to E3 are the same, the deleted image E1 and E2 can be restored based on the hash value of the image E3 since the deleted images E1 and E2 are identical to the image E3. To prevent such restoration, it is necessary to add a random number to each of the images E1 and E4.
However, when random numbers are added, data of the number of GOP×random number length are further required to be stored. Therefore, data other than the moving images to be stored further increases. For example, when a PIAT signature is given to a moving image of one hour long having a frame rate equivalent to that of television, the signature data requires several hundred kilobytes to several megabytes. The amount of data is small compared to that of the image data, however, the amount of signature related data increases.

Method and apparatus for digital signature authentication, and computer product


An outdoor, self-contained wood fueled furnace. The furnace includes a non-warping, laminated sheet metal door; a rear exiting flue with water discharge means; and a baffled, heat exchanger which surrounds the firebox. The door, particularly, includes an external panel which is secured with a single pin to a crossbroken first panel. An insulator is secured between the first panel and a second interior panel, and the first and second panels are riveted to each other.

The present invention relates to wood or coal fueled heating systems and, in particular, to a self-contained furnace which mounts externally of the structure or premises being heated.
With increasing heating fuel costs for gas and petroleum products, alternatively fueled heating systems have experienced a resurgence in popularity. Wood and coal fired stoves, boilers and furnaces are increasingly being used as the primary or as a supplemental heat source. This is especially true in the northern-tier states where alternative, low-cost fuel supplies are available and winters tend to be long and cold.
Many of these stoves mount within the structure being heated. That is, the heating appliance is typically contained within a utility room or finished room of the dwelling. Either radiant heat is obtained or an intermediate heat exchange carrier or media is heated and conducted about the premises.
Unfortunately, the increased use of fuels that produce relatively large amounts of creosote and improper stove and flue maintenance has resulted in increased numbers of related fires and resultant increased insurance premiums. Many manufacturers of stoves and furnaces intended for use as primary heating systems, therefore, now construct there stoves as self-contained assemblies. These assemblies are mounted external to the premises to be heated. The risk of fire and smoke damage to the premises is thereby reduced.
With the removal of the firebox from the premises, larger fireboxes become more practical, along with longer burn times between each recharging or refueling. Consequently and depending upon the fuel, burn times of one to multiple days can be obtained between each re-charging of the stove. Stoves may now also be used over a longer heating season, since the residual radiant heat does not overheat the premises during milder fall or spring days. As these stoves are also made to burn more efficiently, the flue temperatures have been reduced.
With reduced flue temperatures, however, increased amounts of creosote and water vapor are created which can significantly reduce the life of the firebox, especially where a top mount flue is provided. That is, large amounts of moisture accumulate as part of the combustion process and can amount from one to many quarts a day. This water accumulates in the ash to form an acidic lye compound which corrodes away the firebox in a matter of months.
An additional problem effecting the cost of the stove and operational safety can develop at the fire door. Depending upon the stove construction, warpage can occur in the door during the normal cycling of the stove. The warpage may be significant or not and may even permanently effect the door. In all cases, however, warpage tends to create unintended drafts and unregulated burning. A non-warping door construction is therefore desired.
With the foregoing considerations in mind, applicant has developed an improved self-contained wood or coal fueled furnace.


Status information concerning a condition of a network peripheral device connected to a network is automatically communicated to a remote service organization. First, a condition of the network peripheral device is detected. Then, in response to the detected condition, status information is automatically obtained, the status information corresponding to the detected condition. Finally, upon obtaining the status information, a packet is automatically transmitted to the remote service organization via the network, the packet containing the status information.

1. Field of the Invention
The present invention concerns techniques by which a network peripheral device may send an automatic service request over the world wide web or other network and means for implementing such techniques.
2. Description of the Related Art
Traditionally, when a peripheral device such as a network copier required manufacturer's servicing, the user was required to first notice the condition necessitating service, such as inoperability or an error message displayed by the peripheral device, by physically inspecting the device. Then, the user had to notify the manufacturer's technical support or servicing department, for example by placing a telephone call or faxing a service request form. This latter step often involved locating and providing various types of information to the manufacturer's technical support department, and presented a significant potential for error in communicating the information accurately.
One method has been proposed by which a peripheral device requiring service would initiate a modem connection to the service organization and then would communicate servicing request information via the modem connection. However, such a method has several drawbacks. First, in order for the recipient to effectively use data transmitted via a modem connection, it is generally necessary for the recipient to have software which is specifically compatible with the sender's in order to decode the transmitted data. Second, using the modem connection technique generally only allows a service organization, such as technical support, to receive service requests over periods during which it maintains a server connected to a modem at a preestablished telephone number.

Automatic service requests over the world wide web


The invention relates to a network comprising a plurality of network nodes. At least part of the network nodes are directly intercoupled via at least one star node. The star node contains a plurality of star interfaces which are assigned to at least one network node. A star interface is provided for transferring a message from the assigned network node to the other star interfaces or from another star interface to at least one of the assigned network nodes always in dependence on a pilot signal.

The invention relates to a network comprising a plurality of network nodes. Such networks may be installed, for example, in private cars, in industrial automation (for example, sensor systems) and domestic automation (for example, lighting, alarm systems, heating system, air-conditioning system, etc.).
In such a network for private cars can be used, for example, the TTP protocol (TTP=Time-Triggered Protocol) known from the journal "Elektronik", No. 14, 1999, pp. 36 to 43 (Dr. Stefan Blenda, Georg Kroiss: "TTP: "Drive by Wire" in greifbarer Nähe"). This protocol makes a reliable data transmission possible and may therefore also be used in networks concerning safety devices (for example brakes). Said article mentions a bus system as a network structure.

Network comprising a plurality of network nodes and at least one star node


A system and method for assigning received channels to preset tuning keys of a receiver. A series of preset keys are sequentially labeled and one preset key, such as the preset key marked “0,” is a pre-defined preset key. An elongated pressing of the pre-defined key causes the currently tuned channel, if it is not assigned to a preset key, to be assigned to an unassigned preset key. If the currently tuned channel is already assigned to a preset key, pressing the pre-defined key instead causes the currently selected channel to be un-assigned from that preset key. Radios with two tuners that each process different sets of radio signals assign channels for a particular tuner to alternating preset keys, allowing acceleration of sequentially selecting channels assigned to pre-set keys by pre-tuning another tuner to the next channel in the sequence.

Electronic devices used to receive broadcast signals, such as audio radios, often facilitate the user's control of the device by providing programmable operator interface keys. In the case of radios, a number of programmable "preset keys" are usually provided that allow a user to assign a particular radio channel to each of the programmable preset keys. These preset keys are especially useful for the use of radios in an automobile where it is desired to minimize a driver's distraction in selecting a different received radio channel. Preset keys are also used in portable radios and in all types of radios due to their general convenience. Once a channel is assigned to a preset key, the user is able to cause the radio to select that channel by simply pressing the preset key to which that channel is assigned. By assigning different channels to each preset key, the user is able to quickly select a number of favorite channels by simply pressing the associated preset key.
Advances in technology allow an increasing number of preset keys to be provided on a single radio. The user interfaces of such radios typically do not display, in a comprehensive or convenient manner, the channels that are assigned to all of the preset keys. A user wishing to determine which channels are assigned to the preset keys is usually required to press each preset key and remember which channels are assigned to each. This becomes increasingly difficult as the number of preset keys increases. Furthermore, radios typically do not indicate which preset keys have channels already assigned. When a user wishes to assign a new channel to a preset key, there is no way to easily confirm which preset keys is not already assigned a channel that is desired by the user and which the user does not wish to overwrite with the new channel. This often requires a user to sequence through all preset keys to determine which preset key can be overwritten with the assignment of the new channel. The user is also not sure, unless the user inspects the setting of all of the preset keys, if the "new" channel is already assigned to a preset key.
New radios signals are digitally modulated and may require a significant amount of time to process the signal. This can result in a delay when a radio's signal processor is changed to another channel. This delay can produce an undesirable gap in the programming presented to the user.
Therefore a need exists to overcome the problems with the prior art as discussed above.

This patent is subject to a terminal disclaimer.

Radio preset key assignment method and apparatus


Exemplary embodiments provide manufacturing methods for forming a doped region in a semiconductor. Specifically, the doped region can be formed by multiple ion implantation processes using a patterned photoresist (PR) layer as a mask. The patterned PR layer can be formed using a hard-bakeless photolithography process by removing a hard-bake step to improve the profile of the patterned PR layer. The multiple ion implantation processes can be performed in a sequence of, implanting a first dopant species using a high energy; implanting the first dopant species using a reduced energy and an increased implant angle (e.g., about 9° or higher); and implanting a second dopant species using a reduced energy. In various embodiments, the doped region can be used as a double diffused region for LDMOS transistors.

Lateral double-diffused metal oxide semiconductor (LDMOS) transistors require that the LDMOS transistors have a low on resistance, a high off resistance, and a large electrical safe operating area. To increase the current handling capability of the LDMOS transistors on an integrated circuit, a number of LDMOS transistors are often tied together forming, for example, multi-fingered LDMOS. With the LDMOS transistors connected in parallel, the current flow can be shared among the various LDMOS transistors. To ensure the proper distribution of current among the various LDMOS transistors, it is important that the threshold voltage (Vt) of the individual LDMOS transistor structures be closely matched.
The threshold voltage (Vt) of the LDMOS transistor is set by the multiple ion implantation processes used to form the transistor channel region. During the multiple ion implantation processes, a patterned photoresist (PR) masking layer is formed over the substrate and the dopant species are implanted through patterned openings formed in the PR masking layer. In forming the LDMOS transistors required for high current applications, a major limitation to obtaining closely matched threshold voltages is the variation in the photoresist sidewall angle of the various openings through which the dopants are implanted. For example, the photoresist sidewall angle is significantly decreased depending on local resist density, such as after the photoresist hard bake step of a conventional photolithography process.
Thus, there is a need to overcome these and other problems of the prior art and to provide methods for forming LDMOS transistors with closely matched threshold voltages.

LDMOS transistor double diffused region formation process