Abstract: A projection type image display device provided with an unauthorized use preventing system includes a button unit or a remote controller for operating the display device, a condition memory for storing information indicating at least one use condition in an authorized use of the display device, a password memory for storing a password for releasing a restriction on the use of the display device, a detector for detecting a used condition of the display device at a power on timing, and a processor for imposing restrictions on the use of the display device when the use condition detected by the detector does not match the at least one use condition indicated by the information stored in the condition memory and for relieving the restriction based upon input of the password.

Abstract: A refresh area is taken advantage of when a series of images are coded using Intra-frame coding and Inter-frame coding, a partial area of an image being forcefully Intra-frame coded (Intra MBs) in the refresh area. As the prediction mode for prediction of the Intra MBs inside the refresh area, a prediction mode is selected where the prediction is executable based on only the image that exists inside the refresh area.

Abstract: When a super resolution technology for optical disks is used in a situation where optical disk management information is formed with a signal that cannot be reproduced by a reproduction method based on a conventional optical disk technology, optical disk drives cannot make recording adjustments and/or reproduction adjustments. An optical disk drive uses an optical disk that forms a management information signal with pits not smaller in size than optical resolution and can be read by a reproduction method based on a conventional optical disk technology. When the optical disk drive records information onto or reproduces information from the optical disk having the super resolution region, it is possible to make proper recording adjustments or reproduction adjustments and perform a proper recording operation or reproducing operation in an optical disk's information region for user information recording or reproduction.

Abstract: A method of reproducing data from a recording medium, each of the data including reference time information indicating a reference time and including packet data, the method including: reproducing the data from the recording medium; obtaining a difference between respective reference times indicated by the reference time information of the reproduced adjacent data; rearranging the data on a time axis such that a time interval between adjacent data is equal to the obtained reference time difference; and outputting the rearranged data.