Sony announced the development of its small digital recording cassette with a new format called "MICROMV," and the introduction of a digital camcorder called "DCR-IP7," using the new cassette. Sony said this is "the world's smallest and lightest camcorder."

The company employed its new MICROMV format for developing the camcorder and realized the smallest camcorder size of 47mm wide by 103mm high by 80mm deep with a reduced weight of 370g (including battery). And for the first time, Sony adapted a Bluetooth interface, a short-distance wireless data-transmission technology.

Because it is equipped with a Bluetooth interface, camcorder users can access the Internet through either a Bluetooth-enabled modem or a Bluetooth-enabled mobile phone. This makes it possible to achieve the uploading of short video clips and still images filmed by the user (on the Internet). Also, the camcorder is equipped with other functions such as attaching short video clips and still images onto emails, and browsing Web pages.

It will be available from Oct. 10. Although it is open priced, Sony expects the market price to be around 170,000 yen. (120.20 yen = US$1)

"We wanted to cut the camcorder's size, but also sought not to reduce its functions and features. For example, the camcorder LCD monitor panel is larger than those of current camcorders," a Sony official said.

The company had overcome the essential obstacles to achieve a significant reduction in the camcorder size, the bulky tape-cassette and its mechanical-deck, through developing the new MICROMV format. Sony plans to offer new concepts of camcorders to mainly those users of around 30 years old.

"So far, camcorders have been restricted to use as family tools. From now on, we expect them to be widely used as personal mobile tools with increased network-friendliness," the Sony official said.

The MICROMV format cassette size is 46.0mm wide by 30.2mm deep by 8.5mm high. It has achieved 60 minutes of continuous digital video data recording, even though its cassette size is only a third that of the current DV cassette.

Sony adapted the following leading-edge technologies: (1) MPEG2 digital data compression technology, and (2) a high-density data recording technology of three times the data density of the current DV format.

Sony selected an MPEG2 encoding speed of 12Mbps. The high-speed data transfer of around 12Mbps in MPEG2 data processing is enough to obtain a high-quality recording. The image data can be reduced to half the data of current DV format recordings through adopting the MICROMV format. But, its power dissipation was as large as around 1W in an encoding operation using the conventional MPEG2 codec LSI. Thus, Sony developed an original MPEG2 codec LSI called "CXD2890" for use with a 48Mb DRAM. The CODEC LSI is manufactured using the 0.18-micron CMOS processing technology, and its power dissipation is reduced to only about 170mW in its encoding mode.

To obtain a higher recording density, Sony developed high-density magnetic recording technology with a narrower head track-pitch and the shorter wavelength of recording signals than those of the current DV format. The MICROMV format has a head track-pitch of 5-micron, half the current track-pitch of 10-micron. To follow the narrower head track-pitch, Sony developed and adapted a new head scanning means of "double-scanning," performing double scanning on the same track line.

The double-scanning makes it possible to track with better tolerance of the optimum playing-head positions on the recorded tracks of a magnetic tape and reduce the playback data errors. The recording wavelength of data signals is shortened to 0.29-micron while the current DV format-recording wavelength is 0.49-micron.

On the other hand, the shorter recording wavelength and the narrower head track-pitch results in a lower playback head output, and as a result it tends to get more error output data. To overcome this error-signal generation, the MICROMV format camcorder adopted a MR-head for its playback head. Sony said it succeeded in developing a four times larger output level compared with that of the conventional inductive-head.