The LTH write-once BD-R media feature an organic dye recording layer, making them different that the currently available BD-R discs that use inorganic materials. The "Low to High" technology (LTH, in groove recording) was included in the "Blu-ray Disc Recordable Format Ver.1.2" specifications.
Current Blu-Ray drives cannot read the LTH BD-R discs. That because the reproduced signal while reading the discs has a LTH (Low to High) polarity. Panasonic's release of the new firmware for its DiGA BD recorders indicates that a firmware upgrade on existing BD drives could add support for LTH discs.
The advantages of the LTH manufacturing technology is that it can be applied without requiring large-scale manufacturing plant investments, allowing for using modified CD-R and DVD-R manufacturing equipment.
Pioneer and Mitsubishi Chemical Media have announced that they have developed the first LTH discs last September. Taiyo Yuden, Fuji Photo Film and Hitachi Maxell are also expected to release LTH BD-R discs next year.
For additional information about the Panasonic's firmware release, visit http://panasonic.jp/support/bd/info/download.html (Japanese).