Abstract: A method and apparatus for investigating subsurface ground of a site to obtain and store information about soil conditions by pushing into the ground a cableless unit that includes a memory storage device able to collect the information throughout the whole investigation process. After completion of the process, the memory storage device is lifted up to the surface of the ground and is connected to a data processing unit located on the ground to extract the collected information on soil conditions.

Abstract: A color electrophotographic copying process utilizing the Carlson process. A colored original to be copied is color-separated and read by a solid-state image pickup device. Color compensation or gradation compensation is carried out on the basis of the data read by the solid-state image pickup device. When the color compensation is effected, amounts of masking are determined on the basis of the data read by the solid-state image pickup device, and the color-separated latent images are partially erased in an area-modulating manner dependent on the determined amounts of masking with an eraser having a light-emitting dot array. When the gradation compensation is effected, the latent images are partially erased with the eraser in an area-modulating manner dependent on the determined amounts of masking, or an appropriate gradation reproduction curve is selected on the basis of the data read by the solid-state image pickup device.

Abstract: A method of and an apparatus for producing duplicates of a document in color wherein a plurality of photosensitive members in drum form are rotated in the same direction and exposed to respective color-separated optical images of the document through respective arrays of gradient-index rod lenses to form electrostatic latent images on the photosensitive members while the document is supported on a document support member and moved in the same direction as the rotation of the photosensitive drums. The electrostatic latent images on the photosensitive members are developed in different colors into visible images of different colors which are printed by transfer-printing on a sheet of support material on a transfer-printing belt moved in a direction opposite the direction of movement of the document support member for light exposure of the photosensitive members.

Abstract: Multicolored image forming apparatus wherein image processing is accomplished by exposing a photosensitive drum through an exposure optical device to the reflected light beam from the document illuminated with a lamp, reading the document image by an image sensor, energizing, by means of the processed signal of the output of the sensor, each LED in an eraser consisting of an LED array offset from the exposure slit center along the photosensitive drum in the width direction thereof, and erasing it.The light source simultaneously illuminates the document illumination position for slit exposure and a position offset from its center by a distance equal to the displacement between said erase position and the exposure position. The image sensor receives the light beam reflected from the document.

Abstract: A dual-color electrophotographic copier includes a first photosensitive drum having a first layer comprised of a photoconductive material sensitive to light of a first selected color and a second layer formed on the first layer from a photoconductive material sensitive to light of a second selected color and a second photosensitive drum having a third layer comprised of a photoconductive material sensitive at least to the first selected color. A light image from the same original may be applied to the first and second drums simultaneously to form electrostatic latent images on the first and second drums. These images may be developed by differently colored toner and the toner images may be transferred to the same transfer paper superposingly to obtain a dual-color copy image.

Abstract: A recording apparatus has a donor roller which is driven to rotate at a first peripheral speed and has a layer of uniformly charged fine toner particles, a multistylus recording head for forming a charge pattern on the toner layer, and a transfer roller which is rotated opposite in direction to the donor roller and at a second peripheral speed which is slower than the first peripheral speed. A recording medium is advanced between the donor and transfer rollers at a speed equal to the second peripheral speed, whereby a transferred toner image of increased density is obtained.

Abstract: A color recording method wherein equal amounts of photoconductive toner particles of three primary colors are uniformly mixed and applied as a layer on a doner member. Optical color images are projected onto this layer, thereby selectively decreasing the resistivities of the toner particles in patterns corresponding to the optical color images. Simultaneously or immediately thereafter there is applied a voltage thereacross, thereby selectively injecting charge into the photoconductive toner particles with decreased electric resistivities to form a charge distribution in the mixed toner layer corresponding to the projected optical color images. Using the charge distribution formed in the mixed toner layer, color recording is then performed by transferring the toner particles to a recording sheet in accordance with the charge distribution.

Abstract: An information image of a first original and an information image of a second original are synthesized on a photoconductor which includes a photoconductive layer having a spectral sensitivity to A-colored light but not having a spectral sensitivity to B-colored light, and a photoconductive layer having a spectral sensitivity to B-colored light, but not having a spectral sensitivity to A-colored light, which are formed in layers on a conductive base member, by taking the steps of charging the photoconductor to a predetermined polarity and then charging the photoconductor to reverse the original surface potential of the photoconductor, while retaining the charges applied to the photoconductor, to the extent that latent electrostatic images can be formed on the surface of the photoconductor, and exposing the photoconductor to an A-colored light image corresponding to the information image of the first original and a B-colored light image corresponding to the information image of the second originals simultaneous

Abstract: A photographic member includes an electrically conductive substrate which carries a pair of photoconductive layers thereon, which are charged to opposite polarities from each other, as will be further defined herein. The photosensitive member has a surface potential which is of either positive or negative polarity. Subsequently, the photosensitive member is imagewise exposed to light image formed by light of a wavelength which principally renders only one of the photoconductive layers conductive. Areas of the photosensitive member which are irradiated by the light radiation during the imagewise exposure is subjected to a line scanning by a light spot having an extremely small diameter and of a wavelength which principally renders the other conductive layer conductive either simultaneously with or after the imagewise exposure. The spot has a reference light intensity, which is modulated by a pair of write signals.

Abstract: A photoconductive material (11) coated on a drum, belt or sheet (22) is formed with a first photoconductive layer (11b) which is insensitive to red light, a second photoconductive layer (11d) which is sensitive to red light and a transparent insulating layer (11c) formed either between the photoconductive layers (11b), (11d) or on top thereof. The outer surface of the material (11) is radiated with white light while applying a first electrostatic charge thereto rendering both photoconductive layers (11b), (11d) photoconductive. Then, the material (11) is radiated with red light rendering only the second photoconductive layer (11d) photoconductive while applying an electrostatic charge of opposite polarity. Then, a third electrostatic charge of the same polarity as the first electrostatic charge is applied in the dark. The result is that electrostatic charges of opposite polarities are formed at the outer surfaces of the first and second photoconductive layers (11b), (11d).

Abstract: A photoconductive member (11) has a conductive substrate (11a) on which is formed a first photoconductive layer (11b) which is insensitive to red light but sensitive to at least one other color component of white light and a second photoconductive layer (11c) formed on the first layer (11b) which is sensitive to red light. A first electrostatic charge of a first polarity is formed at the interface between the first and second layers (11b), (11c). A second electrostatic charge of a second polarity is formed on the second layer (11c). A light image having black, white and red areas is radiated onto the second layer (11c). The white light causes both layers (11b), (11c) to conduct and dissipate all charge. The red light causes only the second layer (11c) to conduct to form a bipolar electrostatic image.

Abstract: A photoconductive material (11) is provided which has first and second photoconductive layers (13), (14) of different spectral sensitivities. The material (11) is charged at least twice to form a stratified charge pattern of opposite polarities. A color light image of an original document (24) is radiated onto the material (11) to form an electrostatic surface potential pattern having high and low potential areas of one polarity and another area of the opposite polarity corresponding to three respective colors. The areas are developed separately using toners of the three respective colors to form a three color toner image which is transferred to a copy sheet (36). One of the colors may be black.

Abstract: A photoconductive drum formed with two photoconductive layers of different spectral sensitivty is charged a first time in the dark or while rendering one of the layers conductive and a second time with an opposite polarity in the dark to form a stratified electrostatic charge pattern. Exposure to a light image of an original document causes the layers to conduct according to color. Toner particles of two colors such as red and black adhere to respective areas of the resulting electrostatic image which have opposite polarities. Transfer of the resulting toner image to a copy sheet produces a finished copy in two colors.

Abstract: A photoconductive drum (22) is formed with first and second photoconductive layers of different spectral sensitivities. First and second chargers (12), (14) apply electrostatic charges of opposite polarities to the drum (22) to form a stratified charge pattern. Radiation of a light image onto the drum (22) causes electrostatic images to be formed in the layers according to color, the net surface potential being negative in areas corresponding to one color such as red, positive in areas corresponding to another color such as black and zero in white background areas. First and second developing units (27), (28) apply positively charged red toner and negatively charged black toner respectively to the drum (22) to form a two color toner image. Where only one charger (12), (14) and only one developing unit (27), (28) is actuated for operation, a positive or negative copy in either color may be produced.

Abstract: A converging lens projects a light image of an original document along an optical path onto the surface of a photoconductive drum. A dichroic mirror is disposed in the optical path to reflect the light image and has a reflectance characteristic selected in accordance with the spectral sensitivity characteristic of the drum. Unwanted wavelengths are transmitted through the dichroic mirror and absorbed by an absorption plate. The dichroic mirror and absorption plate are housed in a hermetically sealed casing with the converging lens being fixed to and constituting a portion of the casing.

Abstract: A photosensitive member for use in an electrophotographic apparatus in which a bias potential is applied to the member during development. The member comprises a conductive support having at least one support edge and a photosensitive layer formed on the surface of the support and extending up to a point substantially coincident with the support edge. A tapered surface is formed at the extremity of the photosensitive layer adjacent to each support edge which extends from the top of the photosensitive layer to the support edge. The maximum angle between a tangent of the tapered surface and the surface of the conductive support is less then 45.degree. thereby preventing an edge effect by which a background smearing in the form of a black band may appear on copied paper obtained. Such a tapered surface can be easily formed through a vaporizing technique with a special masking in accordance with the present invention.