Abstract: A recording/reproducing apparatus (115) includes a storage section (117) having a content attribute database (DB1) and a point database (DB2). Further, a point calculating section (120) of the recording/reproducing apparatus (115) extracts attribute information sets for each content item from the content attribute database (DB1). Further, deletion factor points associated with deletion factors corresponding to the extracted attribute information sets are extracted from the point database (DB2) for each content item, and evaluation points are calculated in accordance with the extracted plural deletion factor points. This allows the user to appropriately reserve a space required in a recording medium.

Abstract: A collective content consisting of a plurality of partial contents holding license information including a use condition can be appropriately used according to the use condition contained in the license information in each of the partial contents. A content use control device includes an input/output I/F, license generation unit, output control unit, content reproduction unit, and use control unit. The partial content holding the license information including the use condition is inputted via the input/output I/F. License information is assigned to each of the partial contents inputted and constituting a collective content. Single license information collecting the assigned license information and its collective content are outputted to a recording medium. The content use control device reproduces a partial content contained in the collective content recorded on the recording medium and controls the use of the reproduced partial content according to its use condition.

Abstract: There is provided an information recording medium that reduces operation of shifting information backward or putting information forward closer together upon recording/deleting/dividing information to facilitate processes of recording/deleting/dividing information. An information recording medium records Programs 1 composed of image data, etc., UPGR 3 that refers to at least a part of the Programs 1, PGRG 5 that refers to the UPGR 3, a PGRM that collectively records the UPGR 3 and reference information thereof, and a PGRGM that collectively records the PGRG 5 and reference information thereof. When recording the UPGR 3, the information recording medium refers to the reference information contained in the PGRM, and when invalid reference information or reference information giving no reference to any UPGR 3 is present, records the UPGR 3 using the reference information.

Abstract: To enable a recording device recording a video/audio signal and information necessary for utilizing the video/audio signal to copy the video/audio signal with the converted bit rate, encoding format, etc., to another recording device when utilizing the video/audio signal by the another recording device, and to move only the information necessary for utilizing the video/audio signal between the recording device and the another recording device. A recording device comprises: an input portion that inputs a video/audio signal; a recording portion that records the video/audio signal and information necessary for utilizing the video/audio signal; and a converting portion that converts the recorded video/audio signal. The recording device, leaving the original video/audio signal, copies the video/audio signal whose bit rate, encoding format, etc.

Abstract: When data whose storage period is limited by copy control information is temporarily stored in a removable recording medium, the data are encrypted and decoding information (encryption key) necessary to decrypt the encrypted data is held on the device side. By doing so, the data cannot be used beyond a permitted period of the temporary storage. A storage device has an external input/output I/F for removably connecting a removable recording medium; a reception section for receiving copy control information and data (such as video data), the storage period of which data is limited by the copy control information; an encrypting section for encrypting the received data; and a control section for storing the encrypted data in the removable recording medium and storing decryption information (encryption key), necessary to decrypt the encrypted data, in a place in the storage device, outside the removable recording medium.

Abstract: A collective content consisting of a plurality of partial contents holding license information including a use condition can be appropriately used according to the use condition contained in the license information in each of the partial contents. A content use control device includes an input/output I/F, license generation unit, output control unit, content reproduction unit, and use control unit. The partial content holding the license information including the use condition is inputted via the input/output I/F. License information is assigned to each of the partial contents inputted and constituting a collective content. Single license information collecting the assigned license information and its collective content are outputted to a recording medium. The content use control device reproduces a partial content contained in the collective content recorded on the recording medium and controls the use of the reproduced partial content according to its use condition.

Abstract: There is provided an accounting system for accounting a content distributed by an accumulation broadcast or a removable recording medium while preventing an unauthorized use and holding privacy of a user. An accounting ID specifying the money information stored in a prepaid card is read and a content ID of the encrypted content specified by the user and the accounting ID are reported to an accounting server. Decoding information is acquired in return for the accounting and the encrypted content is decoded by using the decoding information so as to be used.

Abstract: The invention is intended to represent a three-dimensional image of an object just as observable from a viewing point, allowing representation of a semi-transparent image on the condition that its rear side may not transparently visible. A three-dimensional image display device according to the present invention is composed essentially of a laser light source, a modulator, an X-Y deflector, a control computer, an image data memory, a moving flat screen and a projection lens. The screen is constructed of a large number of pixels (e.g., 100 by 100 pixels) and each of the pixels is composed of a large number of diffraction elements (e.g., 5 by 5 diffraction elements). On the basis of three-dimensional image data and desired view-point data, both control and image-data preparing computers perform ON-OFF control of laser radiation onto diffraction elements having different reflection directions to determine displaying condition of a pixel composed of said diffraction elements.