Abstract: A speech signal coding apparatus inputs a pitch period generated by coding a speech signal, and outputs information on a range for said pitch period, together with the pitch period. A speech signal decoding apparatus inputs the pitch period and the above information on the range, and determines whether or not the pitch period is within the range. When the pitch period is determined to be within the range, the speech signal decoding apparatus outputs the above pitch period. When the pitch period is determined not to be within the range, the speech signal decoding apparatus outputs as a pitch period a predetermined value within the range.

Abstract: A speech coding system is provided where input speech is coded by finding via an evaluation computation a code vector giving a minimum error between reproduced signals obtained by linear prediction analysis filter processing, simulating speech path characteristics, on code vectors successively read out from a noise codebook storing a plurality of noise trains as code vectors and an input speech signal and by using a code specifying the code vector. In the speech coding system, the noise codebook includes a delta vector codebook which stores an initial vector and a plurality of delta vectors having difference vectors between adjoining code vectors. In addition, provision is made in the computing unit for the evaluation computation of a cyclic adding unit for cumulatively adding the delta vectors to virtually reproduce the code vectors.

Abstract: A color image forming apparatus has a plurality of developing units each including a developing sleeve and storing a developer of particular color. The developing sleeve is located to face a photoconductive element or similar image carrier. When the supply of the developer from the developing sleeve to the image carrier begins or ends, a magnet brush formed on the sleeve by the developer is slowly brought into or out of contact with the image carrier. As a result, a load acting on the image carrier due to the brush contacting it is slowly applied and cancelled. This eliminates changes in the moving speed of the image carrier and thereby insures desirable image quality.

Abstract: A method for detecting a transition of an echo path used for an estimation of the transfer function of a system by using an adaptive filter, from an echo caused by a signal transmitted through an input terminal of the system at which the response of the transmitted signal is received. The method includes the steps of calculating the amount of the whole or the first delay portion of an impulse response of the system, calculating the amount of the remaining delay portion of the impulse response of the system, calculating the ratio between the amount of the whole or the first delay portion of the impulse response and the amount of the remaining delay portion of the impulse response, and deciding an occurrence of a transition of the characteristics of the system based on the calculated ratio. The transition of the characteristics of the system is discriminated from a hindering signal produced in the system in the decision making process.

Abstract: An image forming apparatus has a plurality of developing containers for developing an electrostatic latent image of a latent image carrier by toners having colors different from each other except for black; a black developing container for color for storing black toner for color and operated when the developed image on the latent image carrier every color is overlapped and transferred onto a transfer material to provide a color image; a black developing container for a monochromatic image for storing black toner for a monochromatic image and operated when the monochromatic image is obtained; and a device for arranging the respective developing containers such that the developing containers are opposite to the latent image carrier. The other image forming apparatuses are also shown.

Abstract: A tampon has an absorbent material and an accommodation barrel for accommodating the absorbent material therein. The accommodation barrel includes an absorbent material accommodating portion for accommodating therein the absorbent material and a clamping portion continuously connected with the absorbent material accommodating portion and has a flexible property. The clamping portion is formed as a large diameter portion which is provided with a ring on an outer circumferential edge thereof.

Abstract: A device for use in electrostatographic image recording equipment for retaining and transporting a paper sheet, document or similar sheet member. A transporting member is implemented as an endless belt. An AC voltage is applied to the belt to form a charge density pattern on the surface of the belt, while the charge density pattern sets up a non-uniform electric field in close proximity to the surface of the belt. The non-uniform electric field urges the sheet member against the belt and thereby allows it to be surely transported by the belt to a predetermined position without being dislocated.

Abstract: An echo canceller in a system, having a long impulse response such as in an acoustic system, which employs a fast Fourier transform to transform input data represented in the time domain into signals represented in the frequency domain to reduce calculations. To solve the problem of a long delay, the impulse response length is divided into a plurality of blocks. Each block then has a decreased number of samples within each block. Thus, a fast Fourier transform and finite impulse response type digital filtering are effected, so that the processing delay is decreased while the amount of calculations is kept small.

Abstract: A color recording apparatus has an electric charge carrier which is circulatingly movable, an electrostatic latent image forming unit for forming a latent image which corresponds to an original image on the carrier, a development unit for developing the latent image; a transfer unit for transferring the developed image formed on the carrier to a record paper in a transfer process, a conveyor for conveying the record paper forward and backward with respect to the transfer unit, and a control unit which repeats control operations for controlling the latent image forming unit to form a latent image on the carrier, for controlling the development unit to develop the latent image, for controlling the conveyor to convey the record paper forward, for controlling the transfer unit to transfer the developed image to the record paper, and for controlling the conveyor to convey the record paper backward at least for one time.

Abstract: A rotary multicolor developing apparatus having a plurality of developing chambers defined in a rotatable developing drum, which neighbors and faces a photoconductive drum, and developing units each being disposed in a respective one of the developing chambers to supply toner of a particular color; the developing units being sequentially transported in a rotational motion to a predetermined developing region so that the toner is transferred from each developing unit to an electrostatic latent image provided on the photoconductive drum, thereby developing the latent image. In each developing unit, there are provided a magnetic brush which is sequentially transported between a toner supply region, the developing region, and a toner recovery region, a toner supply roller for transporting toner which is charged in the toner supply region to the magnetic brush, and a toner recovery roller for collecting in the toner recovery region the toner which remains on the magnetic brush after development.

Abstract: A plurality of photosensitive drums are arranged such that color-separated light images of an original document are formed respectively thereon. The photosensitive drums are independently driven under equal conditions by a single drive source for preventing image colors, i.e., image positions, from being shifted out of registry on an image transfer sheet.

Abstract: A composite copying method in full colors, a single color, two colors and black and white and a color copier for practicing the method are disclosed. While toner images of different colors are sequentially transferred onto a paper, the paper is retained by a support member. The timing at which the paper is to be separated from the support member is controllable from outside the copier.

Abstract: A color copier scans an original carrying a multi-color image in one direction to form toner images of different color components thereof on respective photosensitive drums while moving a transfer sheet in the opposite direction to transfer in registration thereon the several toner images and thereby form a composite color image of the original without reversing the rotational direction of the drums. After the latent image on a given drum is developed with a toner of a respective color, the drum is quenched to remove residual charge by irradiating it with light of a color which is not significantly absorbed by the toner on the drum. The quenching light color differs as between different drums, and for a given drum the quenching light color differs from the color of the light used to form the latent image on that drum.

Abstract: An optical system for a color copier in which light images of blue, green and red produced by color separation are formed one on each of three photoconductive elements, then developed by toner of associated colors, and then transferred one upon another onto a paper. A first mirror is disposed in an optical path to which light representative of an image of an original document is led through an image-forming lens and a mirror group. Light reflected by the first mirror is focused onto a first photoconductive element. Light transmitted through the first mirror is split by a second mirror which is located in a position for intercepting a part of the width of a slit for exposure. Light reflected by the second mirror is focused onto a second photoconductive element. Further, light outside the range of the second mirror is reflected by a third mirror to be focused onto a third photoconductive element. The first mirror has a spectral characteristic which reflects light of one of three colors, i.e.

Abstract: A portable image forming device which is moved on an original in a direction perpendicular to a primary scan direction for subscan, and divides original reflection light beams into picture pickup elements in the primary scan direction through an image forming optical system to imageform the pickup elements on a pickup device for reading. The pickup range of the pickup device in the primary scan direction is designed to be variable, and means for setting the pickup range is provided. With a portable copying machine which houses the pickup device and a printing section including a writing head in a single casing, paper is fed to the printer section as required by making use of the movement of the machine for original scan.

Abstract: In a color copying apparatus including a plurality of photosensitive members and a mounting table driven by a pulley, in which an original mounted on the mounting table is illuminated to expose the respective photosensitive members with reflected light from the original to thereby form latent images thereon while the mounting table travels and these images, after developed, are transferred overlappingly onto a transfer paper to produce a color copy, a distance between exposing positions for adjacent photosensitive members is an integer multiple of a peripheral length of the pulley.

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: In a copying apparatus which comprises a plurality of rotatable photosensitive members and an image transfer belt rotatably movable in synchronism with the photosensitive members and in which visible image formed on the photosensitive members are transferred onto a transfer paper carried by the transfer belt, a pair of sensors are arranged around the transfer belt which has a pair of marks thereon and an initiation and a termination of a preprocess are performed prior to a copying process on the basis of detections of these marks by the sensors.

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.