Abstract: On a conversion plane of image data, first through third points (Q.sub.H, Q.sub.S, Q.sub.D) are provided. The first and second points are determined in accordance with highlight and shadow points of an original image, respectively, while the third point is determined in accordance with a dummy shadow point of the original image. A conversion curve (C.sub.a, C.sub.b) is so determined as to pass through the first and second points and to extend along a straight line (L) connecting the first and third points in the highlight region of the coordinate plane.

Abstract: Halftone dots are formed on the basis of three sets of screen pattern data assigned to the to a same combined area, in which a plurality of halftone dots are to be formed. The three sets of screen pattern data have different threshold values assigned to respective pixels in the combined area, and are stored in SPM's (101-116). Eight SPM's (Screen Pattern memory units) store a first set of the screen pattern data, six SPM's store a second one, end two SPM's store a third one. One of the sixteen SPM's is randomly selected with respect to each pixel, whereby one of the threshold values (D.sub.s) stored in the selected SPM is compared with an iamge signal (V.sub.1). A dot signal indicating whether or not each pixel is solid is produced on the basis of the comparison. Accordingly, a grid-like pattern of halftone dots to be seen in a highlight area or a shadow area is prevented.

Abstract: A speed control method for a servomotor, capable of smoothly rotating the servomotor without causing pulsating rotation even when the servomotor rotates at low speeds. On the basis of the numbers of feedback pulses (P2k(m-1)-k+1, . . . , P2km) detected and stored at intervals of a period (TS/2k) equal to a value obtained by dividing an estimated speed calculation period (TS) by an integer multiple of 2, the number (A) of feedback pulses in each estimated speed calculation period and the number (B) of pulses in a time period from a midpoint ((m-1)TS-TS/2) of an estimated speed calculation period immediately before each estimated speed calculation period to a midpoint (mTS-TS/2) of each estimated speed calculation period are calculated, and an estimated speed indicative of an actual rotation speed of the servomotor is further calculated on the basis of the thus calculated numbers (A, B) of pulses.

Abstract: An automatic nominal data setting method in a visual sensor system is capable of accurately and rapidly setting nominal data with ease, and a correction data deriving method is executable on the basis of the automatically set nominal data. If operation of the visual sensor system in a nominal mode is determined (S200) upon start of execution of an orientation portion of a user program by the visual sensor system mounted on an industrial robot, a message for interrogating whether or not nominal data setting should be executed is displayed (S201). When an operator inputs a nominal data setting command (S202), the workpiece position/posture data in the sensor coordinate system at that time, determined based on gray-scale image data, is converted into workpiece position/posture data in the robot coordinate system to be stored as nominal data (S203).

Abstract: Screen patterns for respective color components are represented by arrays of unit regions. The arrays for respective color components have a same array pitch and a same array orientation. Color component images are converted into color component halftone dot images through the screen patterns. When the density of the color component images is in a predetermined range, the color component halftone dot images have a plurality of linear dot elements in each unit region. The plurality of linear dot elements extend in a predetermined direction which is different for each color component.

Abstract: An electromechanical control device is disclosed usable for piloting a vehicle, comprising a piloting control stick articulated on a support via an articulation with two degrees of freedom and so with two output axes, a detection assembly comprising position sensors associated with each of these axes, two electromechanisms acting on the axes via two respective transmission devices, so as to oppose to the movements of the control stick resistant forces in accordance with a predetermined force law. The transmission device comprises a resilient connection disposed in series.

Abstract: Backlash compensation for a numerical control apparatus. Backlash compensation is intelligently applied based on a judgment as to a change in direction or velocity commanded for a cutting tool, table, or the like. Backlash compensation data is stored into a memory of a numerical control apparatus. A judgement is made as to the necessity of backlash compensation, based on velocity data of the feed mechanism, and deciding whether the feed mechanism is being stopped or reversed. Compensation data is output to a servo drive unit.

Abstract: An apparatus for processing a rotary member, comprising: a rotational drive for driving the rotary member so as to rotate the rotary member about an axis of the rotary member; an encoder for detecting a rotational position of the rotational drive device; a control device for controlling, in response to an output signal of the encoder, the rotational drive device so as to rotate the rotational drive device at a uniform speed; a processing device for processing an arbitrary position of the rotary member rotating at the uniform speed; a position detecting device for detecting, on the basis of the output signal of the encoder, a rotational position of the rotary member by raising a resolution of the output signal of the encoder; and a processing control device for controlling the processing device on the basis of the rotational position of the rotary member detected by the position detecting device.

Abstract: A system for converting gray-level input data into binary output data and efficiently preserve much of the original sharpness information. The input data is divided into halftone cells which correspond to several pixels in the original image information. The halftone cells are further divided into subcells which correspond to a plurality of pixels in the halftone cell. The subcells are thresholded with a matrix of threshold values to determine which binary pixels are to be rendered. Any error between the rendered pixels and the average density value of the subcell input values is propagated to adjacent subcells. The thresholding of the subcell pixels can use a separate threshold value for the individual pixels or can use an average threshold value for the entire subcell.

Abstract: A drill motor control for periodically varying the rotational speed of a drill to increase the cutting efficiency of the drill bit is disclosed. The speed of the drill is made to vary according to a predetermined cycle such that the drill bit is permitted to bite into the material being drilled at lower speeds, and then the speed is increased to a point where maximum cutting efficiency is achieved. The drill motor control may either be a stand alone apparatus into which a conventional drill is plugged or alternatively may be incorporated into the drill itself. A closed loop control system which senses drill motor current may be utilized to cause the drill motor to slow down as current to the motor decreases when the drill bit ceases its cutting action such as when glazing occurs or when the drill bit has cut completely through the material being drilled. The drill motor control is also useful when the drill is being used as an electric screwdriver.

Abstract: A method and system for color and monochromatic printing wherein ordered dither and error diffusion processes are combined to provide high quality printed images with good spatial resolution, good gray scale transitions, good low frequency and high frequency responses and a high computational speed. Using this process, gray scale numbers representative of a scanned image are summed for each super pixel of the scanned image and divided by a chosen gray level normalizing factor. This division operation is done to obtain a normalized ordered dither quotient number of drops (dots) to be printed in super pixels and to further obtain an error remainder number of dots to be dispersed to surrounding super pixels. The normalized ordered dither quotient number of dots are printed in pre-assigned individual pixels within printed super pixels, and the error remainder number of drops are diffused to other pre-assigned surrounding or adjacent super pixels.

Abstract: A multi-play compact disk player having a magazine holding a plurality of discrete programmed compact disks. The magazine remains stationary and a housing in the player is rotated with an arm movable to pick up a preselected one of the disks and move the same to a playing area for playing the same. The player can receive thereon a plurality of stacked magazines, each magazine holding a plurality of compact disks.

Abstract: Circuitry and methods are provided for AC line synchronization of the firing means for phase-controlled thyristors in a DC motor speed control system. A line synchronization method and system is disclosed which eliminates zero offset in the phase command input function. This zero offset, which is cuased by motor counter EMF, occurs in prior art controllers which use zero crossings of the AC line voltages for line synchronization of thyristor firing. This invention provides line synchronization timing intervals of constant duration that terminate at the coincidence of AC line voltage and motor counter EMF with the coincidence being the latest time at which the particular thyristor being controlled is forward biased in the absence of current flow. Application to N-phase AC to DC converters for DC motor speed control is disclosed.

Abstract: An apparatus for controlling an operating speed of an electrically controlled device including an electrically operated member. The apparatus includes an error signal generator for generating an error signal indicative of an error between an actual and a target value of the operating speed, a reference signal generator for generating a reference signal, a comparator for generating an output signal based on a result of comparison between the error and reference signals, and an energy control device for controlling an energy supplied to the electrically controlled device by controlling the duty cycle of an electric current applied to the electrically operated member such that the energy varies with the output signal of the comparator. A device is provided for changing the reference signal depending upon a load currently applied to the electrically controlled device.