Abstract: A technology for detecting an RFID by a reader writer and transmitting harmonics for reading and writing the RFID timely without using an object detection sensor is provided. Using a nonlinearity of a rectifier or a demodulator in an IC chip of the RFID, a continuous wave or a modulated wave of two or more different frequencies is output from the reader writer. The RFID receives the continuous wave or the modulated wave of two or more different frequencies and the reader writer receives harmonics intermodulation generated by the rectifier or the demodulator in the IC chip. Therefore, the RFID can be detected without any special object detection sensor, and a modulated wave for reading or writing the RFID can be transmitted.

Abstract: An IC tag system is provided which can perform transfer of a method of accessing an IC tag and assure data validity of the IC tag only between authorized users. The IC tag system comprises a data write-in device including a password encryption unit (130), a signature generation unit (140) and a data write-in unit (150) operative to communicate with the IC tag (30) to write in data and an encrypted password in the IC tag (30) and set the limitation on access to the data written in the IC tag (30) by the aid of the password, and a data read-in device including a password decryption unit (230), a signature authentication unit (240) and a data read-in unit (250) operative to communicate with the IC tag (30) to read in the data and the encrypted password from the IC tag (30) and release the limitation on access to the data by the aid of the decrypted password.

Abstract: An Radio Frequency Identification Device (RFID) for receiving commands transmitted from a reader/writer of a RFID system to which the RFID belongs, having a demodulation circuit comprising a variable LPF, a binarization circuit connected to the variable LPF, a transmission rate detection circuit for detecting the transmission rate of a received command from an output signal of the binarization circuit, and a control circuit for setting the bandwidth corresponding to the maximum transmission rate of the received command as the reception bandwidth of the variable LPF in the initial state, and changing the reception bandwidth of the variable LPF according to the detected transmission rate of the received command.

Abstract: A technology for detecting an RFID by a reader writer and transmitting harmonics for reading and writing the RFID timely without using an object detection sensor is provided. Using a nonlinearity of a rectifier or a demodulator in an IC chip of the RFID, a continuous wave or a modulated wave of two or more different frequencies is output from the reader writer. The RFID receives the continuous wave or the modulated wave of two or more different frequencies and the reader writer receives harmonics intermodulation generated by the rectifier or the demodulator in the IC chip. Therefore, the RFID can be detected without any special object detection sensor, and a modulated wave for reading or writing the RFID can be transmitted.

Abstract: A technique of reducing the interference wave occurred between a plurality of reader/writers in an environment in which a plurality of RFID systems are operating. An RFID system includes a plurality of reader/writers and a controller for controlling the plurality of reader/writers. Each reader/writer includes a body, antennas, and a distributor for selecting one antenna from the antennas. The controller selects an antenna having a positional relationship in which the interference wave is small from the antennas of each reader/writer, and giving a command for the antenna to the body of each reader/writer. Each reader/writer selects one antenna from the antennas based on the command from the controller and transmits a command to the RFID.

Abstract: In order to provide a highly secure system at a low cost without providing a complicated logic circuit for an RFID tag, in a system including an RFID tag (10) and a interrogator (20), the interrogator (10) is provided with a password creating unit (1100) which computes an electronic key (131) and a keyword unique to the RFID tag with a predetermined irreversible function to create a password. By using the password as a key, item information of an item attached with the RFID tag (20) is encrypted with a predetermined encryption function. The encrypted item information and the keyword are written to the RFID tag (20). The interrogator (10) reads the encrypted item information and the keyword from the RFID tag (20), causes the password creating unit (1100) to compute the password by using the keyword, and uses the password as a key to decrypt the read encrypted item information.

Abstract: A reader/writer (R/W) transmits a query command ALL (A), which causes RFID tags (A) with a communication method (A) to respond at a time, to N RFID tags (A) with the communication method (A) and X RFID tags (C) with a communication method (C). In this case, since R/W receives responses from N RFID tags (A), it can recognize presence of the RFID tags with a communication method (A) from its reception level or the like. Next, R/W transmits a query command ALL (B) which causes RFID tags (B) with a communication method (B) to respond at a time. In this case, since R/W receives no response, it can recognize that no RFID tag with the communication method (B) is present rapidly. In an RFID system, therefore, a communication time between RFID tags and an RFID reader/writer can be reduced.

Abstract: In a case where the services are used jointly among plural users with the use of shared electronic keys, a method which invalidates only the electronic keys of some users is provided.

Abstract: A graphics system which accelerates generation of pixels including transparent objects by simply adding more rendering devices. The system has composition means and a plurality of rendering devices each comprising a geometric processor, a rendering processor and a frame memory that holds color, depth and weight data in a screen bit map format. Given a plurality of sets of color, depth and weight data about any one pixel position from the frame memories, the composition means first compares the depth data, and multiplies successively the weight and color data starting with those corresponding to the depth data closest to the foreground, thereby generating new pixel data. The system thus permits merging of transparent objects.

Abstract: A graphics system utilizes the graphics standardization specification PEX for providing high-speed drawing when a client and a server locally operate on the same machine and allow an application to change structure and graphics attributes defined by another application without being aware of the distinction between local and remote cases.

Abstract: A plurality of texture data of a surface of an object to be displayed as viewed from a plurality of assumed directions are stored in a texture memory. When a CPU sends to a graphic processor information specifying a shape of the surface, a direction to view the surface and a texture in the texture memory as a command, a geometric operation unit produces read information of the texture memory based on the input information. A triangle generator reads the texture data corresponding to the view direction of the surface of the object by the read information for texture mapping. An image of the texture mapped image of the surface of the object is stored in a frame memory and displayed on a monitor. When there is no texture data corresponding to the view direction, a plurality of texture data closest thereto are read from the texture memory and interpolated to produce an appropriate texture data.

Abstract: Intensities of light reflected from a surface of an object to be displayed are calculated as to values of an ambient light reflection component, a diffuse light reflection component, and a specular reflection component. Judgement is made as whether the calculated value of the specular reflection component exceed a predetermined value. Texture data are blended with a sum of the calculated ambient light reflection component value and the calculated diffuse light reflection component value. If it is judged that the calculated specular reflection component value exceeds the predetermined value, the specular reflection component value is added to the blended value of the texture data with the sum of the calculated ambient light reflection component value and the calculated diffuse light reflection component value.

Abstract: A distributed drawing processing system which includes a drawing server for integratedly executing a string of drawing commands transmitted from a client program for graphics display. In the system, the client program divides the drawing command string into a drawing command block of a string of drawing commands processable on a parallel basis and a drawing command block of a string of drawing commands not processable on the parallel basis, and transmits the divided drawing command string blocks to the drawing server. The drawing server executes the drawing command string while judging whether to process it on the parallel or sequential basis with respect to each of the divided drawing command string blocks.

Abstract: An Icon window display area taking precedence over all other display areas is disposed in the display screen. A window which becomes invisible at generation of a new window, a window size change of an existing window, or a position change of an existing window represented as an Icon which the operator can recognize or identify is the invisible window displayed in a new Icon window display area.

Abstract: An Icon window display area taking precedence over all other display areas is disposed in the display screen. A window which becomes invisible at generation of a new window, a window size change of an existing window, or a position change of an existing window is reduced to a predetermined size so as to be displayed in a new Icon window display area.