Abstract: An optical pickup device comprises a light source to emit a light flux having wavelength &lgr;; an objective lens including at least two plastic lenses of a first plastic lens having positive refractive power and a second plastic lens having positive refractive power, wherein the first plastic lens and the second plastic lens are arranged in this order from the light source side; and an actuator to drive the objective lens; wherein the objective lens satisfies the following expression (1-1):

Abstract: A formed lens produced by pressing an optical material so as to shape a predetermined configuration, has an optical surface having a light entrance side, a light exit side and an optical axis. When a normal line angle is defined as an angle formed between the optical axis and a normal line at an arbitrary point on the optical surface, the maximum normal angle is 60° to 90° and an intersection at which the maximum normal line forming the maximum normal line angle intersects with the optical axis is located at the light exit side from the point of the maximum normal line on the optical surface, and Abbe's number &ngr;d of the optical material is 60 or more.

Abstract: An objective lens for recording information on and/or reproducing information from and optical information recording medium, comprises a diffractive structure including ring-shaped diffractive zones on at least one surface thereof. The objective lens is a single lens made of plastic material, at least on surface thereof is an aspheric surface, and the following conditional formula is satisfied; NA≧0.7 where NA represents an image side numerical aperture necessary for recording on and/or reproducing from an optical information recording medium.

Abstract: There is described a strobe device particularly suited for image capturing apparatus equipped with wide-angle lens. The strobe device includes a reflector to reflect a strobe light, a light-emitting tube to emit the strobe light and an optical panel to transmits the strobe light. In the strobe device embodied in the present invention, a maximum luminous intensity of the strobe light, illuminated by the strobe device, is arranged in a direction being different from a direction of a strobe light axis.

Abstract: An objective lens for recording and/or reproducing an optical information recording medium, comprises a first lens having a positive refractive power; and a second lens having a positive refractive power; wherein the first lens and the second lens are aligned in this order from a light source side of the objective lens; first lens and the second lens are respectfully made of material having a specific gravity of 2.

Abstract: A zoom lens includes, in the order named from an object side: a first lens group having a positive focal length; a second lens group having a negative focal length; and a third lens group having a positive focal length. A magnification is changed by moving said second and third lens groups in an optical axis direction of said zoom lens, and satisfies the following condition, 3.0<Lt/(L{square root over (Z)})<6.0 where Lt represents a distance between a lens surface closest to the object side of said first lens group and an image plane, L represents a diagonal length of the image plane, and Z represents a variable magnification ratio showing a ratio of a focal length at a wide angle end to a focal length at a telephoto end.

Abstract: In a zoom lens having a variable power ratio representing a ratio of a focal length at a telephoto end position to a focal length at a wide angle end position being not less than 2.5 times, the zoom lens includes, in the order named from an object side: a first lens group having a negative focal length; a second lens group having an aperture-stop and a positive focal length; and a third lens group having a positive focal length. When a magnification is varied from the wide angle end position to the telephoto end position, all of the first, second and third lens groups are moved in an optical axis direction of the zoom lens so that a distance between the first and second lens groups is decreased. The first lens group Includes, in the order named from the object side, a first positive lens whose convex surface faces the object side, a second negative meniscus lens whose convex surface faces the object side, a third negative lens, and a fourth positive lens.

Abstract: An image forming apparatus includes: a first reading device for reading an image recorded on a recording medium; a storing device for storing a signal of a reference image representing a reference to correct the image recorded on the recording medium; a second reading device for reading a chart image obtained by recording the reference image; a calculating device for calculating image correction data by comparing the signal of the reference image with a signal of the chart image; an image processing device for correcting the image signal read by the first reading device on the basis of the image correction data; and an outputting device for outputting an image on the basis of the image signal corrected by the image processing device.

Abstract: An electronic still camera comprises solid-state image pickup elements arranged such that a pixel pitch is P (mm); an optical low-pass filter; an image pickup lens for focusing the image light through the optical low-pass filter onto the solid-state image pickup elements, the image pickup lens having resolving power X (lines/mm) at an optical axis when the image light is focused on the solid-state image pickup elements; wherein the following condition is satisfied:1/F.lambda.>X>1/Pwherein F represents F-number and .lambda. is 550.times.10.sup.-6 (mm).

Abstract: A charge generation layer and a method of manufacturing a charge generation layer of a highly sensitive organic photoconductor for electrophotography is provided, wherein the charge generation layer is formed by using a dispersion liquid in which an organic pigment or dye is so dispersed as to be fully utilized as a charge generation agent. The organic pigment or dye is dispersed and pulverized in a dispersing solvent, with ball-shaped pulverizing media of about 0.1 to about 0.3 mm in diameter, to an average particle size of from about 0.1 to about 0.3 .mu.m. The ratio of the organic pigment or dye to the solid components of the dispersion liquid is set at about 5 to about 95 weight %. The ball-shaped pulverizing media are removed from the dispersion liquid prior to dip coat formation of the charge generation layer. The total weight of the ball-shaped pulverizing media is set at about 0.25 to about 5 times as heavy as the weight of the dispersion liquid.

Abstract: A zoom lens includes, in the order named from an object side, a first lens group having a positive refracting power and a second lens group having a negative refracting power, in which magnification change is conducted by changing a distance between said first and second lens groups. The first lens group has, in the order named from the object side, a 1a lens component having a negative refracting power, including a 1-1 lens having a negative refracting power and a 1-2 lens made of a plastic material, at least one surface of which is an aspherical surface, and a 1b lens component having a positive refracting power. The second lens group has, in the order named from the object side, a 2-1 lens having a positive refracting power made of a plastic material, at least one surface of which is an aspherical surface, and a 2-2 lens having a negative refracting power. The zoom lens satisfies the following conditional expression,2.5<f.sub.T /f.sub.W3.0<f.sub.T /f.sub.1 <5.0where f.sub.

Abstract: A camera for taking a photograph on a picture plane of a rolled film which has a width of 24 mm. The camera includes: a photographing lens of which a convex surface is faced toward an object to be photographed and satisfying: 18.ltoreq.f.ltoreq.32 and f.sup.2 /90.ltoreq.F.ltoreq.16 in which f is the focal length of the photographing lens and F is the F-number of the photographing lens; at least one diaphragm; and the picture plane having a picture frame satisfying: 23.ltoreq.L.ltoreq.32 and 1.5.ltoreq.L/S 6.5 in which L (mm) is the long dimension of the picture frame, S is the short dimension of the picture frame, and an image of the object is focused on the picture plane through the photographing lens and the diaphragm.

Abstract: A photographic lens includes a first meniscus lens having a positive refracting power, a convex face of which is directed to a photographic object side, and includes a second meniscus lens having a positive refracting power, a concave face of which is directed to the photographic object side. The first and second lenses are arranged in this order from the photographic object side. The photographic lens is composed in such a manner that the following conditional expressions are satisfied:0.60<f/f.sub.1 <0.75-3.2<(r.sub.4 +r.sub.3)/(r.sub.4 -r.sub.3)<-2.5where f represents a focal length of the photographic lens, f.sub.1 represents a focal length of the first meniscus lens, r.sub.3 represents a radius of curvature of the concave surface facing the object side of the second meniscus lens and r.sub.4 represents a radius of curvature of a surface facing an image plane side of the second meniscus lens.

Abstract: An electrophotographic photoreceptor consists of an intermediate layer on a conductive substrate. A photosensitive bilayer is coated on the intermediate layer. The outermost layer if the photosensitive bilayer contains a combination of an ester phosphite antioxidant and a hindered phenol antioxidant. This organic photoreceptor has improved resistance to performance degradation and degradation in repetition characteristics from exposure to active gases (such as ozone). A method of producing the electrophotographic photoreceptor according to the invention is also taught.

Abstract: A photoconductor for electrophotography comprises an electroconductive substrate and a photosensitive layer formed on the conductive substrate and including a charge generating material and a charge transporting material. The charge transporting material comprises at least one compound selected from indole compounds represented by the following general formula (I) and at least one compound selected from benzidine compounds represented by the following general formula (II).

Abstract: The photoconductor for electrophotography comprises an electroconductive substrate and a photosensitive layer formed on the substrate. The photosensitive layer may be a monolayer or function-separated laminate type one which comprise a charge generating layer and a charge transporting layer laminated one on another. The charge transporting layer contains a specified diamine compound represented by general formula (I) below as the charge transporting substance. ##STR1## wherein R.sub.1 and R.sub.2, which are the same or different, each represent independently an alkyl group, an alkoxy group, or a halogen atom; R.sub.3, R.sub.4, R.sub.5 and R.sub.6, which are the same or different, each represent independently an aryl group or an alkyl group, or R.sub.3 and R.sub.4, or R.sub.5 and R.sub.6, combine and form a condensed aromatic ring; and X represents an oxygen atom, a sulfur atom, a carbonyl group, or a sulfonyl group.

Abstract: A photographic lens system includes a positive meniscus lens whose the both lens surfaces are shaped in a aspherical surface respectively, the lens is arranged to satisfy the following inequality:0.02<t/L<0.05wherein the length of a diagonal line of an image forming plane on said image forming surface is 2L and the lens thickness on the optical axis is t.

Abstract: A photosensitive member for electrophotography has a photosensitive layer provided on a photoconductive substrate. The photosensitive layer contains at least one of indole derivatives represented by a chemical formula (I): ##STR1## wherein R.sub.1 and R.sub.2 are members selected from a group consisting of hydrogen atom and alkyl, aralkyl, allyl and alkoxy groups having 1-9 carbon atoms (but R.sub.1 and R.sub.2 do not stand for hydrogen atoms at the same time); R.sub.3 is a member selected from a group consisting of hydrogen and halogen atoms and alkyl and alkoxy groups having 1-3 carbon atoms; X is a member selected from a group consisting of alkylen, allylen, carbonyl, sulfonyl, sulfinyl and sulfide groups and oxygen atom; and n stands for an integer of 0 or 1.

Abstract: The photoconductor for electrophotography comprises an electroconductive substrate and a photosensitive layer formed on the substrate. The photosensitive layer may be a monolayer or function-separated laminate type one which comprise a charge generating layer and a charge transporting layer laminated one on another. The charge generating layer contains a specified benzidine compound represented by general formula (I) below as the charge transporting substance. ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4, which are the same or different, each represent independently an aryl group, an alkylaryl group, an alkoxyaryl group or a halogenated aryl group provided that R.sub.1 and R.sub.2, or R.sub.3 and R.sub.4, or both combine and form a condensed aromatic group with the nitrogen atom to which they are bonded, respectively; R.sub.5 and R.sub.6 each represent independently a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom.

Abstract: In a camera in which a 35 mm photographic roll film is used, a positive convex meniscus lens, the convex side of which faces an object to be photographed, an aperture diaphragm and a flare-stop facing an image side are provided. An image plane is curved toward the lens as the image plane advances away from the optical axis of the lens in the longer side direction of the focal surface. The following inequalities are satisfied:26.ltoreq.f.ltoreq.32f.sup.2 /126.ltoreq.F.ltoreq.16in which f represents the focal distance and F represents the F-number of the lens.