Abstract: An optical disk apparatus for a phase-change optical disk detects the boundary between a first region and a second region prior to detecting a synchronization mark. The synchronization mark is detected in accordance with the position of the detected boundary between the first region and the second region. User data is read from a data region in accordance with the detected synchronization mark.

Abstract: A disk recording medium has reliability of address reading which is maintained equivalently to the conventional disk recording medium by recording a first address and a second address that are identical in a header area. By arranging the first and second addresses to be reversely displaced from the center line of a groove track or a land track to the radial direction of the medium, the distance between the first and second addresses when they are adjacent is increased, which eliminates the influence of crosstalk. This avoids redundancy of the header area and enables high-density recording to the disk recording medium.

Abstract: An optical disc is disclosed, having tracks formed in a spiral shape or a concentric circle shape, each of the tracks being radially divided into a plurality of zones, data being recorded and/or reproduced at different angular velocities in the individual zones in such a manner that the angular velocity in the same zone is the same, wherein a buffer area is formed at a zone boundary, and wherein at least one pit portion is formed in the buffer area so that the pit portion is almost radially adjacent to a pit portion of a zone on the inner periphery side and a pit portion of a zone on the outer periphery side.

Abstract: According to the present invention, in a disk-shaped recording medium such as an optical disk and the like, a reference clock with a frequency corresponding to a reproduction frequency of data reproduced from a data recording region is divided in accordance with a ratio between a record density of a header region where pre-formatted data including a sector mark for indicating a leading position of a sector is recorded, and a recording density of a data recording region subsequent to the header region, so as to produce a sampling clock. Then, by use of thus-produced sampling clock, the sector mark is detected. This structure enables, even if the header region has a recording density different from the recording density of the data region, to use a sector mark detector having the same structure as of a sector mark detector which is employed in the case where the header region has the same recording density as that of the data region and therefore a reference clock is used.

Abstract: A disk recording medium has reliability of address reading which is maintained equivalently to the conventional disk recording medium by recording a first address and a second address that are identical in a header area. By arranging the first and second addresses to be reversely displaced from the center line of a groove track or a land track to the radial direction of the medium, the distance between the first and second addresses when they are adjacent is increased, which eliminates the influence of crosstalk. This avoids redundancy of the header area and enables high-density recording to the disk recording medium.

Abstract: An improvement of a photographic film roll composed of a spool which has a spool core having a slit therein and a flange at both ends of the spool core and a photographic 120-size film which is placed and fixed on a continuous light-shielding backing paper in which one end of the backing paper is inserted into the slit of the spool and other portion of the backing paper is wound on the spool to form multiple convolutions, resides in that the backing paper has at the center in its longitudinal direction a width less than the distance between the two flanges measured at the position of ½ of height of the flanges and has two wide areas of at least 10 cm long one of which is within 50 cm area measured from its one end and another of which is within 50 cm area measured from its another end, the width of each wide area being larger than the distance between the two flanges measured at the tops of the flanges.

Abstract: A container is formed for a liquid. In order to reduce a volume of the container for a liquid after use thereof, a bellows portion is provided at an axial direction portion of a container main body. A lid member is removed, and liquid within the container for a liquid is discharged from an opening portion. The bellows portion is contracted so that head space can be adjusted and so that a volume of the container main body can be reduced. Further, because the head space can be adjusted, an interior of the container for a liquid is always substantially filled with the liquid so that oxidation of the liquid can be prevented. When the liquid is poured, the bellows portion automatically expands and contracts so that the liquid flows quickly and so that little air is drawn in. Further, if a certain amount or more of the liquid in the interior is discharged, the volume can be reduced, and a volume-reduced state can be maintained by tightly screwing the lid member.

Abstract: An electrophotographic photoreceptor which has an electrophotographic photoreceptive layer containing as a charge generating material a particular organic compound having the general formula described hereinafter in this disclosure in a combination with a charge transporting material. The compounds improve upon the sensitivity, durability and selectivity to photosensitive wavelengths of photoreceptors. Furthermore, the photoreceptors can be easily manufactured.

Abstract: An electrophotographic light-sensitive printing material having a high sensitivity and forming a good printing plate capable of providing clear copies having less stains at non-image areas is disclosed. The material is comprised of a conductive support having formed thereon an electrophotographic light-sensitive layer containing (a) a hydrazone compound, (b) a barbituric acid derivative, a thiobarbituric acid derivative or other charge generating material, and (c) a resin binder.

Abstract: An electrophotographic photoreceptor is described comprising an N-arylamino substituted hydrazone compound represented by formula (I), (II), or (III), in a light-sensitive layer thereof provided on a conductive support; formulae (I), (II), and (III) are as follows: ##STR1## wherein X represents O, S or N--R.sup.6 ; R.sup.1 and R.sup.2 each represents a non-substituted or a substituted straight or branched chain alkyl group containing from 1 to 12 carbon atoms, a non-substituted or a substituted straight or branched chain aralkyl group containing from 7 to 20 carbon atoms, or a non-substituted or a substituted aryl group, the aryl group including monovalent residues of monocyclic aromatic rings and condensed polycyclic aromatic rings having from 2 to 4 rings therein; R.sup.3, R.sup.4, R.sup.5, and R.sup.

Abstract: An electrophotographic light-sensitive material with an electrophotographic light-sensitive layer containing a charge-generating material and a charge-transporting material is described.The material is characterized in that the charge-generating material is a compound represented by the general formula (I) or (II): ##STR1## (wherein the symbols are the same as defined in the claims).

Abstract: A photoconductive element comprising elemental selenium dispersed in an insulating polymer is prepared by reducing an inorganic selenium compound in the presence of the insulating polymer. The invention also provide a process for preparing an electrophotosensitive material having a photoconductive layer in which reduction of the inorganic selenium compound is performed in a layer coated on a conductive support.

Abstract: An electrophotographic photoreceptor is described comprising an N-arylamino substituted hydrazone compound represented by formula (I), (II), or (III), in a light-sensitive layer thereof provided on a conductive support; formulae (I), (II), and (III) are as follows: ##STR1## wherein X represents O, S or N--R.sup.6 ; R.sup.1 and R.sup.2 each represents a non-substituted or a substituted straight or branched chain alkyl group containing from 1 to 12 carbon atoms, a non-substituted or a substituted straight or branched chain aralkyl group containing from 7 to 20 carbon atoms, or a non-substituted or a substituted aryl group, the aryl group including monovalent residues of monocyclic aromatic rings and condensed polycyclic aromatic rings having from 2 to 4 rings therein; R.sup.3, R.sup.4, R.sup.5, and R.sup.

Abstract: An electrophotographic sensitive material is described comprising an electrophotographic sensitive layer containing a compound represented by the formula (1) ##STR1## wherein R.sup.1 and R.sup.2 each represents an unsubstituted or substituted straight chain or branched chain alkyl group having from 1 to 12 carbon atoms, an unsubstituted or substituted straight chain or branched chain aralkyl group having from 7 to 20 carbon atoms or an aryl group consisting of a monovalent group consisting of an unsubstituted or substituted monocyclic aromatic hydrocarbon or polycyclic aromatic hydrocarbon having from 2 to 4 nuclei from which a hydrogen atom is removed; R.sup.3 represents an unsubstituted or substituted straight chain or branched chain alkyl group having from 1 to 12 carbon atoms, an unsubstituted or substituted aralkyl group having from 7 to 20 carbon atoms or an unsubstituted or substituted aryl group; and R.sup.4 and R.sup.

Abstract: An electrophotographic sensitive material is described having an electrophotographic sensitive layer containing a charge generating material and a charge transfer material, wherein said charge generating material comprises a barbituric acid derivative or thiobarbituric acid derivative represented by formula (I) or (II) ##STR1## wherein (i) X represents an oxygen atom or a sulfur atom(ii) R.sup.1 represents an alkoxy group, an aralkyl group or a substituted amino group represented by ##STR2## wherein R.sup.7 and R.sup.8 each represents an unsubstituted or substituted alkyl group or phenyl group, or R.sup.7 and R.sup.8 together represent a group forming a nitrogen atom-containing heterocyclic ring,(iii) R.sup.2 and R.sup.3 each represents a hydrogen atom, a halogen atom, an alkyl group, or a lower alkoxy group,(iv) R.sup.4 represents a hydrogen atom, an alkyl group, or an unsubstituted or substituted phenyl group,(v) R.sup.5 and R.sup.

Abstract: A function separated type electrophotographic light-sensitive member and a process for production thereof are described, said member comprising an electrically conductive support, a light-sensitive layer made of a hydrogen-doped amorphous silicon semiconductor, and an organic electric charge transport layer containing at least one positive charge transport carrier selected from the group consisting of pyrazolines, aryl-alkanes, arylketones, arylamines and chalcones.

Abstract: A photographic material for recording non-silver images at high sensitivity using a small amount of silver halide, comprising a support, a layer, formed thereon, of a monovalent or divalent copper salt or complex and a hydrophilic binder, and a layer of silver halide formed on the layer containing the copper salt or complex either by vacuum-deposition or sputtering, or by coating a silver halide emulsion. Non-silver images are formed by exposing the photographic material imagewise, and developing the silver halide layer and the copper compound layer either successively with different developer solutions, or continuously in one developer solution. The silver developed acts as a catalyst for the development of the copper compound.

Abstract: A light-sensitive image recording material comprising, as a self-supporting film or in one or more layers on a support, at least(a) a heat sensitive coloring element comprising at least one polyvinyl pyridine and at least one polyvinylidene halide, and(b) a light sensitizing element comprising at least one of(1) a compound which, on exposure to actinic radiation, is capable of complexing the polyvinyl pyridine of element (a) or is capable of forming a quaternary salt with the polyvinyl pyridine of element (a), or(2) a compound which, on exposure to actinic radiation, is capable of releasing a precursor which is capable of complexing the polyvinyl pyridine of element (a) or is capable of forming a quaternary salt with the polyvinyl pyridine of element (a) under heating,and a dry process for recording a light image comprising(1) imagewise exposing to actinic radiation the light-sensitive image recording material described above, and(2) uniformly heating the imagewise exposed light-sensitive image recording mate

Abstract: A heat sensitive color forming and heat sensitive electrical conductivity increasing composition comprising a mixture of (A) a basic polymer which reacts with hydrogen halide and is capable of forming a quaternary salt and (B) a halogen-containing polymer capable of forming a conjugated polyene by the elimination of hydrogen halide; and a heat sensitive image recording sheet containing the same.

Abstract: A method for producing an image comprising image-wise exposing a light-sensitive layer containing a sensitizing agent and an image forming compound which can be transferred at non-exposed areas to an image receiving layer upon heating at about 80.degree. to about 200.degree. C, and which can be changed to a non-transferable compound at exposed areas, contacting the light-sensitive layer with the image receiving layer containing a compound which forms a colored image upon reaction with the image forming compound, and heating the light-sensitive layer to transfer the image forming compound to the image receiving layer at non-exposed areas, wherein the image receiving layer comprises an organic tellurium compound and a binder formed on a support.