Abstract: A hydrazone compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 each are an aryl group or collectively with the carbon to which they are attached form a polycyclic group; R.sub.3 represents a hydrogen or halogen atom or an alkyl or phenyl group; and R.sub.4 and R.sub.5 each represent an alkyl, aralkyl or aryl group, with the proviso that at least one of R.sub.4 and R.sub.5 is an aryl group, is useful as a charge-transporting material in an electrophotographic photoreceptor and are produced by condensing the corresponding aldehyde with the corresponding H.sub.2 N--NR.sub.4 R.sub.5 hydrazine.

Abstract: A method for preparing a magnetic recording medium which comprises the steps:(a) providing on a non-magnetic support, a thin magnetic metal film,(b) providing on the thin magnetic film, a protective layer comprised substantially of carbon,(c) washing the surface of the protective layer at least once, each washing performed with one substance selected from the group consisting of an alkali detergent, a neutral detergent and an organic solvent, and(d) providing on the surface of the protective layer, a lubricating layer containing at least one organic lubricating agent.Where the magnetic recording mediums produced therefrom exhibit excellent lubricating properties and running durability and causes no attachments on a magnetic head. Magnetic disks produced from the magnetic recording mediums also exhibit excellent lubricating properties and running durability and also do not cause attachments on a magnetic head.

Abstract: A ferromagnetic thin film type magnetic recording medium is disclosed, comprising a nonmagnetic intermediate layer formed between a nonmagnetic support and a magnetic layer, the intermediate layer containing a binder resin and ultrafine particles, wherein the ultrafine particles have a diameter of from 5 to 250 nm and (a) the binder resin has as a polar group at least one group selected from the group consisting of --SO.sub.3 M, --OH, --OSO.sub.3 M, --COOM, ##STR1## --NR.sub.2 and --.sym.NR.sub.3 X.crclbar. wherein M is H, Li, Na, K or a hydrocarbon group, R is H, or an alkyl group, and X is a halogen atom, or (b) the peak temperature of the loss tangent (tan) of the binder resin is from 10 to 90.degree. C.The magnetic recording medium has an excellent running durability, still life and frictional property.

Abstract: A single unit remote controller adapted to control predetermined functions of first and second video tape recorders (VTR) connected each other for performing a signal transfer between the first and second VTRs is disclosed. The first VTR is preconditioned to be responsive exclusively to a first remote control code signal (code A) and the second VTR is preconditioned to be responsive exclusively to a second remote control code signal (code B) to perform the predetermined functions. The single unit remote controller comprises function keys corresponding to the predetermined functions of the first and second VTRs for commanding remotely the predetermined functions, code generation unit for generating the code A and code B combined in sequence with an interruption of a predetermined time period therebetween in response to a depression of a specific key of the function keys, and, transmission unit for transmitting the code A and code B generated by the code generation means to the first and second VTRs.

Abstract: A magnetic disk comprising a nonmagnetic support having provided thereon a magnetic layer comprising a ferromagnetic metal powder and a binder resin, wherein the magnetic layer has a mechanical loss tangent, tan .delta., of from 8.times.10.sup.-3 to 6.times.10.sup.-2, measured at a frequency of 110 Hz and in a temperature range of from 20.degree. to 50.degree. C. with a temperature increase rate of 2 deg/min.

Abstract: A magnetic recording medium having on a non-magnetic support a magnetic layer mainly composed of a ferromagnetic metal powder and a binder resin is disclosed, wherein the specific surface area S (m.sup.2 /g) of the ferromagnetic metal powder is from 30 to 65 and the magnetic layer further contains a fatty acid ester in a content Y (% by weight) to the ferromagnetic metal powder of the range of 0.05S+5.5.ltoreq.Y.ltoreq.-0.2S+24 when the specific surface area S is from 30 to less than 50 and the range of 0.06S+4.7.ltoreq.Y.ltoreq.-0.13S+21 when the specific surface area S is from 50 to 65. The magnetic recording medium is suitable for high density recording and exhibits excellent running durability.

Abstract: An improved magnetic recording medium comprises a nonmagnetic support and a magnetic recording layer which comprises a ferromagnetic powder, a lubricant and an abrasive dispersed in a binder comprising a specific polyurethane resin and a specific vinyl chloride copolymer at a ratio (polyurethane resin:vinyl chloride copolymer) in the range of 15:85 to 90:10. The polyurethane resin has a polar group such as --COOM, --SO.sub.3 M, --OSO.sub.3 M and --PO(OM').sub.2, wherein M is hydrogen or an alkali metal atom, and M' is hydrogen, an alkali metal atom or a lower hydrocarbon group, one polar group being contained per 53,000 to 100,000 of the number-average molecular weight of the resin, and the vinyl chloride copolymer has one of the above-mentioned polar group, one polar group unit being contained per 10,000 to 100,000 of the number-average molecular weight of the copolymer.

Abstract: There are here provided a novel tetraphenylthiophene derivative represented by the general formula ##STR1## wherein AM is a tertiary amino group, each of l, m and n is the integer 0 or 1 and l.gtoreq.m.gtoreq.n are useful as the charge-transporting material in an electrophotographic photoreceptor having an electrically conductive base and a photosensitive layer thereon containing a charge-transporting material and a charge-generating material, which preferably is an azo compound.

Abstract: A printed circuit board has the printed circuit shielded against radiation of high frequency signals by upper and lower conductive plates separated from the printed circuit and substrate by resist layer.

Abstract: There are here provided a novel tetraphenylthiophene derivative represented by the general formula ##STR1## wherein AM is a tertiary amino group, each of l, m and n is the integer 0 or 1 and l.gtoreq.m.gtoreq.n are useful as the charge-transporting material in an electrophotographic photoreceptor having an electrically conductive base and a photosensitive layer thereon containing a charge-transporting material and a charge-generating material, which preferably is an azo compound.

Abstract: A magnetic recording medium, having excellent running durability and strong resistance to deformation caused by heat, is comprised of a non-magnetic support and a magnetic layer having provided therebetween, a non-magnetic under-coating comprised of a dispersion of silica fine particles and at least one binder, said binder comprising at least one polymerizable (meth)acrylate compound containing a triazine ring.

Abstract: An undifferentiated symbiotic combination of lichen flora induced from a tissue of lichen flora and having a capability of producing any lichenous substance.

Abstract: A photographic optical device of this invention comprises: a master lens unit having a positive refractive power, determining a photographic optical path and moving along the optical axis to change magnification; a first auxiliary lens unit having a positive refractive power and being capable of being placed on and off the optical path; and a second auxiliary lens unit having a negative refractive power and being capable of being placed on and off the optical path. The first auxiliary lens unit is attached to an image-plane side of the master lens unit to form a photographic unit giving a low ratio of magnification. The second auxiliary lens unit is attached to an image-plane side of the master lens unit to form another photographic unit giving a high ratio of magnification. The first and second auxiliary lens units are placed outside of the optical path to form another photographic unit giving a middle ratio of magnification.

Abstract: A magnetic recording medium is described, comprising a non-magnetic support having provided thereon a magnetic layer containing ferromagnetic particles and a binder, said binder of the magnetic layer containing polyisocyanato-isocyanurate as a hardening component.

Abstract: A magnification change-over device for a camera is provided with an incident optical path for the incidence of the light of an object to be photographed; a first optical path for guiding the object light incident on the incident optical path to a first aperture; a second optical path for guiding the object light incident on the incident optical path to a second aperture; changeover means for selection between the first and second optical paths; and optical means for differentiating the magnification of an image formed through the second aperture from that of an image formed through the first aperture.

Abstract: The disclosed variable magnification finder includes, from front to rear, a first lens unit of negative power, a second lens unit of positive power, a third lens unit of positive power, the first, second and third lens units constituting an objective lens of positive power, and an eyepiece of positive power. The first and second lens units form a finder image on a plane just in front of the third lens unit. The second lens unit is moved axially forward to increase the image magnification, while the shift of diopter of the finder is simultaneously compensated for by moving the first lens unit.

Abstract: Disclosed is a colored polarizing film having excellent durability which comprises (a) an organic polymer film or sheet and (b) at least one dichroic dye having an azo, anthraquinone, thioindigo, perylene or phthalone structure containing no water-soluble group. Also disclosed is a method of making a colored polarizing film using an organic polymer film or sheet formed of a polyamide or polyester resin, which comprises the steps of (a) blending (preferably, dry blending) a dichroic dye with the resinous polymer in advance, (b) melting the resulting blend and forming it into a film, and then (c) stretching the film in at least one direction.

Abstract: An optical system of changeable magnification comprising a master lens arranged normally in axial alignment to an image receptor to be switchable to another light path which includes a rear converter, and a reflection mirror arranged so that when the master lens is switched from the first to the second light path, the light emerging from the converter is directed to the image receptor, while blocking the first light path off the image receptor, thereby the image magnification is changed from one value to another.

Abstract: An abrasive tape comprises a flexible substrate, and an abrasive layer overlaid on the flexible substrate by applying an abrasive coating composition containing abrasive grains and a binder onto the flexible substrate and drying the applied abrasive coating composition. The binder contains a vinyl chloride resin having a --SO.sub.3 M group, where M represents Li, Na or K, and an epoxy group.

Abstract: A magnetic recording medium is described, comprising a non-magnetic support having provided thereon a magnetic layer containing CrO.sub.2 fine particles and a binder, wherein the binder comprises polycarbonate polyurethane in an amount of from about 30 to about 90 wt %, based on the total weight of said binder.