Abstract: A code conversion method and apparatus is provided for scrambling and modulating data. The method and apparatus includes scrambling an input main data unit based on any of plural types of pseudo-random number sequences, and modulating the scrambled main data unit based on any of plural types of modulation data. An output main data unit is produced from the modulated main data unit, and a calculated value representing a difference between a number of 0 bits and a number of 1 bits included in the output main data unit is obtained. Any of the modulation data is then selected dependent upon the calculated value.

Abstract: A digital video disk stores data codes and multifunctional synchronization codes in a data structure. The synchronization codes contain type information code identifying whether the synchronization code is located in a code sequence at the beginning of the data block, the beginning of a data block sector other than the first sector in the data block, the beginning of a line, or the middle of a line. The type information is expressed by two alternative patterns, type information code 1 and type information code 2, expressing the same information and differing in the number of is in the 5-bit sequence, i.e., an odd or even number of 1s. Which one of the two type information code pattern is used is selected according to the DSV so as to minimize bias in the dc component of the frame following the synchronization code.

Abstract: The optical recording medium of this invention includes: a first substrate having a first information surface; a semitransparent reflection film formed on the first information surface of the first substrate; a second substrate having a second information surface; a reflection film formed on the second information surface of the second substrate; and an adhesive layer for adhering the first substrate and the second substrate so that the first information surface and the second information surface face each other, wherein the thickness of the first substrate is 0.56 mm or more, the thickness of the adhesive layer is 30 .mu.m or more, and the total thickness of the first substrate and the adhesive layer is 0.68 mm or less.

Abstract: An optical record carrier and methods and apparatuses for recording and reproducing an information on and from said optical recording carrier, whereby the effects of crosstalk from adjacent tracks is reduced, and stable tracing control is possible, is achieved. A recording track to which information divided into sector units is recorded is formed in a spiral or concentric pattern on the surface of the optical record carrier. Each sector further comprises sixty frames. Each frame comprises a re-sync pattern, frame address, data, and postamble fields. Identification information identifying the sector location of the information is recorded to the data block of the first frame. The user data is recorded after the data is scrambled using a value generated by a fifteen-stage maximum-length sequence generator based on the value of this identification information.

Abstract: The information to be recorded is divided into 8-bit long data words. Each data word is then converted to 14-bit long code word. The code words are sequentially connected with a one-bit merging bit inserted between the code words to define a code bit sequence. The run-length of 0s in the code bit sequence is limited to be between 2 and 11. The one-bit merging bit normally takes a bit value of 0, but is changed to 1 when any one of the T.sub.min control or T.sub.max control is applied so as to accomplish the run-length limitation. The T.sub.min control is applied when the adjacent bits on both sides of the merging bit are 1s. The T.sub.max control is applied when trailing P bits of a code word preceding the merging bit and leading Q bits of a code word following the merging bit are all 0s, provided that P+Q.gtoreq.11, and in this case, at least either one of the P bits and Q bits has a bit sequence of (00000), and the bit sequence (00000) is changed to (00100).

Abstract: An optical record carrier and methods and apparatuses for recording and reproducing an information on and from said optical recording carrier, whereby the effects of crosstalk from adjacent tracks is reduced, and stable tracing control is possible, is achieved. A recording track to which information divided into sector units is recorded is formed in a spiral or concentric pattern on the surface of the optical record carrier. Each sector further comprises sixty frames. Each frame comprises a re-sync pattern, frame address, data, and postamble fields. Identification information identifying the sector location of the information is recorded to the data block of the first frame. The user data is recorded after the data is scrambled using a value generated by a fifteen-stage maximum-length sequence generator based on the value of this identification information.

Abstract: The optical recording medium of this invention includes: a first substrate having a first information surface; a semitransparent reflection film formed on the first information surface of the first substrate; a second substrate having a second information surface; a reflection film formed on the second information surface of the second substrate; and an adhesive layer for adhering the first substrate and the second substrate so that the first information surface and the second information surface face each other, wherein the thickness of the first substrate is 0.56 mm or more, the thickness of the adhesive layer is 30 .mu.m or more, and the total thickness of the first substrate and the adhesive layer is 0.68 mm or less.

Abstract: The collector-top type transistor according to the present invention has at least principal semiconductor layers of an emitter layer, tunnel barrier layers having electron affinities smaller than those of the emitter and a base, the base layer, and a collector layer formed in the above-mentioned order on a semiconductor substrate in which the injection of the minority carriers from the emitter to the base is controlled by the tunneling mechanism via the tunnel barrier layer where the film thickness of the tunnel barrier layer in the extrinsic transistor region is regulated to be larger than that in the intrinsic transistor region.

Abstract: There is disclosed a heterojunction bipolar transistor comprising an emitter region having a first conductivity type, a base region having a second conductivity type opposite to the first conductivity type, and a collector region having a graded collector section formed of a first compound semiconductor material and a collector contact section formed of a second compound semiconductor material of the first conductivity type, and an emitter-base junction, a base-collector junction and an abrupt potential discontinuity are formed between the emitter region and the base region, between the base region and the graded collector section and between the graded collector section and the collector contact section, respectively, wherein the first compound semiconductor material is increased in bandgap from the base-collector junction toward the collector contact section and the second semiconductor material is smaller in bandgap at the abrupt junction than the first semiconductor material, so that the potential differe

Abstract: For improvement in operation speed, there is provided a heterojunction bipolar transistor comprising, (a) an emitter region formed of a first semiconductor material of a first conductivity type, (b) a base region formed of a second semiconductor material of a second conductivity type opposite to the first conductivity type and forming a first junction together with the emitter region, and (c) a collector region formed of a third semiconductor material of the first conductivity type and forming a second junction together with the base region, the heterojunction bipolar transistor has a plurality of abrupt potential discontinuities including first and second abrupt potential discontinuities produced in succession to provide kinetic energies to a carrier injected from the emitter region, respectively, and the first abrupt potential discontinuity is produced at one of the first and second junctions, thereby allowing the carrier to move over a distance longer than a mean free path of the carrier in the ballistic m

Abstract: There is disclosed a photosensitive lithographic printing plate material comprising a photosensitive layer having a slip sheet laid on the surface thereof, said slip sheet comprising natural pulp, 5 to 50% by weight of polyolefinic synthetic pulp and 0.2 to 2.0% by weight of an alkali metal halide.