Abstract: In a file sharing system, a key manager unit realizes a correspondence between the first user identifier and the first public key in response to a registration request of the first user, generates a first key material for encrypting the first file into a first encrypted file, and generates a first credential according to the first user identifier, the first file identifier, the first public key and the first key material after receiving an access-right claim request to the first file from the first user. A file storage unit stores the first encrypted file and the first credential. The first user uses the first user identifier, the first file identifier and the first private key to retrieve the first key material out of the first credential, and uses the first key material to decrypt the first encrypted file into the first file.

Abstract: A safety circuit is provided for a ballast of an electro-luminescent (EL) lamp. The EL lamp had an electrical ground shield on at least a portion thereof and has a separate ground lead. The ballast is an isolated ballast with a line input being isolated from an output. The ballast is constructed and arranged to be electrically connected with the separate ground lead. The circuit includes a current sensing structure constructed and arranged to connect between the separate ground lead and a potential ground of the ballast. In the event a user contacts the EL lamp to replace the EL lamp or contacts a defective EL lamp, the ballast is shut down based on a value of current sensed by the current sensing structure.

Abstract: A ballast (11) includes a variable output DC converter source (12) and an inverter circuit (14) arranged to provide AC output voltage to an electro-luminescent (EL) lamp (16). A Q factor of EL lamp can characterize the age of the EL lamp. A series resonance-parallel loaded circuit and two voltage detector (18, 20) are constructed to measure the Q factor. A processor (17) controls the output of DC voltage source in accordance with a look-up table containing constant brightness algorithm based on the derived voltage and Q relationship.

Abstract: A double-shielded electroluminescent panel includes an electroluminescent device, an upper electrical shield and a lower electrical shield. The upper electrical shield is a transparent conductive material, and is overlaid on the illuminating surface of the electroluminescent device. The lower electrical shield is an electrical conductive material, and is mounted on the non-illuminating surface of the electroluminescent device. The upper electrical shield and lower electrical shield are together connected to the ground line of a power source. Therefore, the occurrence of electromagnetic interference and an electric shock is avoided.

Abstract: A ballast (11) includes a variable output DC converter source (12) and an inverter circuit (14) arranged to provide AC output voltage to an electro-luminescent (EL) lamp (16). A Q factor of EL lamp can characterize the age of the EL lamp. A series resonance-parallel loaded circuit and two voltage detector (18, 20) are constructed to measure the Q factor. A processor (17) controls the output of DC voltage source in accordance with a look-up table containing constant brightness algorithm based on the derived voltage and Q relationship.

Abstract: A ballast (11) includes a variable output DC converter source (12) and an inverter circuit (14) arranged to provide AC output voltage to an electro-luminescent (EL) lamp (16). A Q factor of EL lamp can characterize the age of the EL lamp. A series resonance-parallel loaded circuit and two voltage detector (18, 20) are constructed to measure the Q factor. A processor (17) controls the output of DC voltage source in accordance with a look-up table containing constant brightness algorithm based on the derived voltage and Q relationship.

Abstract: A current limiting device includes a constant current source circuit constructed and arranged to be connected to a direct current input voltage source and to regulate electrical current and a resonance source circuit receiving current from the constant current source circuit. The resonance source circuit is constructed and arranged to be electrically connected with an electro-luminescent (EL) lamp so that the EL lamp receives alternating current. The constant current source circuit and the resonance source circuit are constructed and arranged such that when current flows from the constant current source circuit to the resonance source circuit and to the EL lamp, a maximum peak current received by a user contacting an output of the device or contacting the EL lamp is less than about 0.7 mA.

Abstract: A safety circuit is provided for a ballast of an electro-luminescent (EL) lamp. The EL lamp had an electrical ground shield on at least a portion thereof and has a separate ground lead. The ballast is an isolated ballast with a line input being isolated from an output. The ballast is constructed and arranged to be electrically connected with the separate ground lead. The circuit includes a current sensing structure constructed and arranged to connect between the separate ground lead and a potential ground of the ballast. In the event a user contacts the EL lamp to replace the EL lamp or contacts a defective EL lamp, the ballast is shut down based on a value of current sensed by the current sensing structure.

Abstract: A ballast (11) includes a variable output DC converter source (12) and an inverter circuit (14) arranged to provide AC output voltage to an electro-luminescent (EL) lamp (16). A Q factor of EL lamp can characterize the age of the EL lamp. A series resonance-parallel loaded circuit and two voltage detector (18, 20) are constructed to measure the Q factor. A processor (17) controls the output of DC voltage source in accordance with a look-up table containing constant brightness algorithm based on the derived voltage and Q relationship.

Abstract: A current limiting device includes a constant current source circuit constructed and arranged to be connected to a direct current input voltage source and to regulate electrical current and a resonance source circuit receiving current from the constant current source circuit. The resonance source circuit is constructed and arranged to be electrically connected with an electro-luminescent (EL) lamp so that the EL lamp receives alternating current. The constant current source circuit and the resonance source circuit are constructed and arranged such that when current flows from the constant current source circuit to the resonance source circuit and to the EL lamp, a maximum peak current received by a user contacting an output of the device or contacting the EL lamp is less than about 0.7 mA.

Abstract: An illuminating membrane switch, including: an upper membrane sheet on which a plurality of wires are formed; a lower membrane sheet on which a plurality of wires are formed; and an electroluminescent device interposed between the upper membrane sheet and the lower membrane sheet, the electroluminescent device emitting rays through the upper membrane sheet and having a plurality of openings so as to allow the wires of the upper and lower membrane sheets to contact each other.

Abstract: A ballast (11) includes a variable output DC converter source (12) and an inverter circuit (14) arranged to provide AC output voltage to an electro-luminescent (EL) lamp (16). A Q factor of EL lamp can characterize the age of the EL lamp. A series resonance-parallel loaded circuit and two voltage detector (18, 20) are constructed to measure the Q factor. A processor (17) controls the output of DC voltage source in accordance with a look-up table containing constant brightness algorithm based on the derived voltage and Q relationship.

Abstract: A current limiting device includes a constant current source circuit constructed and arranged to be connected to a direct current input voltage source and to regulate electrical current and a resonance source circuit receiving current from the constant current source circuit. The resonance source circuit is constructed and arranged to be electrically connected with an electro-luminescent (EL) lamp so that the EL lamp receives alternating current. The constant current source circuit and the resonance source circuit are constructed and arranged such that when current flows from the constant current source circuit to the resonance source circuit and to the EL lamp, a maximum peak current received by a user contacting an output of the device or contacting the EL lamp is less than about 0.7 mA.

Abstract: A ballast (11) includes a variable output DC converter source (12) and an inverter circuit (14) arranged to provide AC output voltage to an electro-luminescent (EL) lamp (16). A Q factor of EL lamp can characterize the age of the EL lamp. A series resonance-parallel loaded circuit and two voltage detector (18, 20) are constructed to measure the Q factor. A processor (17) controls the output of DC voltage source in accordance with a look-up table containing constant brightness algorithm based on the derived voltage and Q relationship.

Abstract: A safety circuit is provided for a ballast of an electro-luminescent (EL) lamp. The EL lamp had an electrical ground shield on at least a portion thereof and has a separate ground lead. The ballast is an isolated ballast with a line input being isolated from an output. The ballast is constructed and arranged to be electrically connected with the separate ground lead. The circuit includes a current sensing structure constructed and arranged to connect between the separate ground lead and a potential ground of the ballast. In the event a user contacts the EL lamp to replace the EL lamp or contacts a defective EL lamp, the ballast is shut down based on a value of current sensed by the current sensing structure.

Abstract: An illuminating membrane switch includes an upper membrane sheet, an electroluminescent device and a lower membrane sheet. The electroluminescent device is interposed between the upper membrane sheet and lower membrane sheet on which switch circuits are printed. In addition to emitting rays through the upper membrane sheet, the electroluminescent device has a plurality of openings allowing the switch circuits of them to contact each other. The keyboard utilizes the illuminating membrane switch to detect any input of keystroke and light up the symbols on the surfaces of key caps for a user to identify the function or alphabetic input of each key cap.

Abstract: The present invention discloses a packaged set of luminous disks with DIY surface and a method of its use. The invention is designed for providing consumers an alternative to design the surface of the disk at their will. The packaged set of the present invention basically contains at least one luminous disks and at least one transparent stickers; the luminous disk has a disk lamination and a light-emitting lamination, the transparent stickers has cutting lines defined some specific shapes for users to easily detach from the mother sheet. After designing and printing out the desired patterns on the transparent stickers, the user detaches the transparent stickers and then stick them onto the luminous surface of the luminous disk, a special home-made disk is thus obtained.

Abstract: A portable apparatus disclosed hereinafter comprises a luminous disk and a bracing portion. The luminous disk includes a disk lamination having a substrate and a metallic reflecting layer formed on a surface of the substrate; and a light emitting lamination superposed on the surface of the metallic reflecting layer opposite to the surface of the substrate for emitting light when it receives an external electrical power. The light emitting lamination includes an electroluminescence section, which luminesces in case the external electrical power is supplied thereon, and a biasing section for receiving and applying the external electrical power onto the electroluminescence section. The bracing portion includes a bracing part, a stretching part extended from the bracing part, and a contact part, which combines the luminous disk and the bracing apparatus together, and conducts the electrical power to the luminous disk.

Abstract: The present invention relates to a portable apparatus including a fastening mechanism for use with the light-emitting disk. The clamping area of the light-emitting disk has a plurality of conductive terminals, and the touch portion of the fastening mechanism connected with the conductive terminals can supply electrical power to light up the light-emitting disk. Furthermore, the light-emitting disk can light partially, intermittently or colorfully by itself because the fastening mechanism controls the electrical power in different modes.

Abstract: The present invention relates to a portable apparatus for use with the light-emitting disk. The inner-circle plastic sheet of the light-emitting disk has a plurality of conductive terminals, and the touch portion of a fastening mechanism is used to transfer the power source to the conductive terminals to excite the light-emitting disk to luminesce. The light-emitting disk can be held by users with a fastening mechanism, hung on the chest of a user or placed on a table. Besides, the sponsor of a party, a singing show or a pub can previously record the singer's song on a light-emitting disk, combine the light-emitting disk into a portable apparatus by the teaching of the present invention, and give as a present to viewers or draw lots to determine the prize winners for increasing a scene atmosphere or for advertising effect.