Abstract: First and second acceleration detectors are attached to first and second sections on a driven body, and values of accelerations ?1 and ?2 in a travel direction of the driven body are detected. On the basis of the difference or sum of the acceleration values ?1 and ?2, at least one of a position command, speed command, or current command for performing drive control of the driven body is corrected.

Abstract: A method for changing a force control gain expressed as a ratio of force error to velocity command value in a control circuit performing a force control of a servo motor driving a die cushion disposed opposite to a slide in a press machine. The method includes: obtaining a difference between a displacement of the slide and a displacement of the die cushion in a state in which the slide and the die cushion collide with and are exerting force on each other; detecting the force when the difference of the displacements is obtained; calculating a spring constant of a structural portion based on a proportionality between the difference of the displacements and the force, when regarding the structural portion including the slide and the die cushion as an elastic structure; and changing the force control gain based on the spring constant using a fixed proportionality that exists between the force control gain and a reciprocal of the spring constant.

Abstract: An imaging system includes an infrared lamp to emit infrared light, a CCD camera (5) to pick up an image of a place irradiated with the infrared lamp and convert the picked-up image into an electric signal, and an image processing unit (7) to periodically change a signal accumulation time of the CCD camera and periodically and continuously provide images of different exposure values. The image processing unit extracts a high-brightness block surrounded with a medium-brightness area from a first image of the periodically provided images, and according to a degree of the medium-brightness area, controls a signal accumulation time of a second image to be picked up.

Abstract: A motor control device detects acceleration of an object driven by a motor through a transmission mechanism, determines a correction command based on the detected acceleration of the driven object, corrects an operation command for the motor by the correction command thus determined, and then controls the motor operation based on the corrected operation command. In the process, a phase shifter combines an operation command signal indicating the operation command with a correction command signal indicating the correction command after adjustably changing the phase of the correction command signal with respect to the vibration of the driven object generated due to the natural vibration of the transmission mechanism.

Abstract: A phosphor in which water adsorption onto the surface of a blue phosphor is inhibited, luminance degradation and chromaticity shift of the phosphor is decreased, or discharge characteristics thereof is improved, and a plasma display device using the phosphor. In phosphor layers used for plasma display, selectively coating at least the vicinity of the sides of planes of mirror symmetry containing Ba atoms in a blue phosphor with an oxide or a fluorine-containing oxide inhibits water adsorption onto the surface of the blue phosphor, decreases luminance degradation and chromacity shift of a phosphor, or improves discharge characteristics thereof.

Abstract: An electric motor control unit (10) comprises: a first position detecting means (31) for detecting a position of a mechanical movable portion (24) driven by an electric motor (20); a second position detecting means (32) for detecting a position of a rotary shaft (21) of the electric motor; a usual operation time movement command outputting means (12) for outputting a usual operation time movement command (Mc) by which the rotary shaft (21) of the electric motor is usually operated, and a stoppage time movement command outputting means (13) for outputting a stoppage time movement command (Mc0) by which the rotary shaft of the electric motor is stopped.

Abstract: A controller for a servomotor capable of improving accuracy of positioning and quality of a machined surface by switching modes of correction of a position command or the like, and reducing a shock at the time of switching. A correction amount generating section obtains a correction amount based on a value of a correction factor such as machine temperature. When the external signal is in ON state, a position command or the like is corrected by the correction amount obtained by the correction amount generating section and sent via switches. A correction amount holding section holds the correction amount obtained by the correction amount generating section. When the external signal turns to OFF state, the connection of the switches is changed so that correction is performed by the correction amount held in the correction amount holding section. When the connection of the switches is changed, the correction amount does not change rapidly, so that the machine does not suffer a shock.

Abstract: A motor control system capable of securing stability and rapidity of motion even in a machine where the stability varies in accordance with a position of a driven member. The driven member and a motor for driving the driven member are operatively connected through a transmission mechanism including a nonlinear element such that a rate of change of the position of the driven member with respect to the position of the motor varies in dependence on the position of the motor. Optimum values of multiplier factors of operation constants with respect to the position of the driven member or the rotational position of the motor for the position control and the velocity control are stored in a data table. The values of the multiplier factors of the operation constants for a present position of the driven member or a present position of the motor are determined using the data table and the determined values of the multiplier factors are multiplied by reference operation constants to update the operation constants.

Abstract: A method of manufacturing a plasma display device which prevents the brightness of a phosphor layer from lowering is disclosed, and the method can form the phosphor layer in a stable manner because a nozzle is free from clogging. At least one of the phosphor layers has a green phosphor layer containing green phosphor having zero or positive charges and a crystal structure of Zn2SiO4:Mn. Green phosphor ink, whose major ingredient is the green phosphor, is applied through the nozzle to discharging cells, thereby forming the green phosphor layer. The green phosphor ink is formed of green phosphor powder coated with an oxide having positive charges, or the ink is formed by crushing the green phosphor powder originally having negative charges and a crystal structure of Zn2SiO4:Mn such that the powder changes to have positive charges.

Abstract: A plasma display device exhibits suppressed luminance degradation of a phosphor, a suppressed change in chromaticity and improved discharge characteristics as a result of suppression of adsorption of water or hydrocarbon-containing gas on a surface of a blue phosphor. A blue phosphor layer used in the plasma display device is formed of a compound expressed by Ba1?XMgAl10O17:EuX or Ba1?x?ySryMgAl10O17:EuX and includes at least one element that is selected from Nb, Ta, Pr, P, As, Sb, Bi and Tm which substitutes for a part of its Al or Mg element.

Abstract: A die cushion controller, for driving a die cushion, disposed in opposition to a slide of a press machine, by controlling a servo motor, including: a pressure command portion which prepares a pressure command value for exerting a predetermined pressure to a press material disposed between the slide and the die cushion; a pressure detecting portion which detects an actual pressure exerted on the press material; a speed correction value preparing portion which prepares a speed correction value by multiplying a differential value of the pressure command value prepared by the pressure command portion by a coefficient; and a first speed command portion which prepares a speed command value to be instructed to the servo motor based on the pressure command value prepared by the pressure command portion, the actual pressure detected by the pressure detecting portion, and the speed correction value prepared by the speed correction value preparing portion.

Abstract: The present invention aims to inhibit water adsorption onto the surface of a blue phosphor(blue fluorescent material), decrease luminance degradation and chromaticity shift of a phosphor, or improve discharge characteristics thereof. Used in a phosphor for a plasma display is a blue phosphor in which trivalent Eu ions substitute for part of divalent Eu ions. This substitution eliminates oxygen vacancy in the vicinity of layers containing Ba atoms (Ba—O layers) in the blue phosphor, and thus inhibits water adsorption onto the surface of the blue phosphor, decreases luminance degradation and chromaticity shift of the phosphor, or improves discharge characteristics thereof.

Abstract: A speed region of a motor is divided into a region lower than a first switch speed VS1, a region higher than a second switch speed VS2 and a region between the first and second switch speeds. An abnormal load determination level to be compared with an estimated load obtained by an observer is set for each of the regions. An abnormal load determination level AL4 applied when an acceleration exceeds a threshold value is set. The abnormal load determination level AL4 is used for comparison with the estimated load until a predetermined period of time elapses after the acceleration to be commanded to the motor, which once exceeded the threshold level, drops. In other cases, the estimated load is compared with the abnormal load determination level having a value according to the speed. If the estimated load exceeds the compared abnormal load determination level, it is judged that a collision is detected.

Abstract: A control device (10) for a die cushion mechanism that produces a force for a slide (24) in a press machine, comprising slide velocity command-forming means (61) for forming a velocity command for the slide (24), die cushion velocity command-forming means (62) for forming a velocity command for said die cushion (20), and velocity relation calculation means (65) for calculating a velocity relation between the velocity of the slide and the velocity of the die cushion based on a rate of increase (dF) in the force produced between the slide and the die cushion immediately after the collision of the slide with the die cushion. The cushion velocity command-forming means forms the velocity command for the die cushion based upon the slide velocity command formed by the slide velocity command-forming means and upon the velocity relation calculated by the velocity relation-calculation means. This makes it possible to form an optimum velocity command for the slide and/or the die cushion.

Abstract: Disclosed is a controller for restraining vibration of a driven element driven by a servomotor. The driven element driven by the servomotor is provided with acceleration detecting means. A correction value is obtained by multiplying a detected acceleration value detected by the acceleration detecting means by a coefficient. Correction is made by subtracting the correction value from a velocity command, and velocity feedback control is executed in a velocity control processing section to obtain a current command. Further, the servomotor is driven by current control processing, whereupon the driven element is moved. If the detected acceleration value is increased by vibration of the driven element, the velocity command is corrected to restrain the vibration, so that the vibration of the driven element can be restrained.

Abstract: There is provided a synchronous control device for driving the same control object with two servomotors. The synchronous control device detects the physical quantity that represents the difference between the forces on the two servomotors, and, on the basis of the detected value, reduces the force that acts between the two servomotors.

Abstract: A plasma display device comprises blue phosphor which restricts adsorption of water and hydrocarbon gases to a surface thereof, reduces degradation of luminance and chromaticity change, and improves discharge characteristic. Among phosphor layers used for a plasma display, a blue phosphor layer comprises one of compounds symbolized by Ba1-xMgAl10O17:Eux and Ba1-x-ySryMgAl10O17:Eux, of which phosphor contains 0.2 to 0.8 in number x of Eu atoms, and the Eu atoms comprises 25% to 85% concentration of bivalent Eu ions, and 15% to 75% concentration of trivalent Eu ions.

Abstract: A device (110) for judging the collision of a slide (24) with a die cushion in a die cushion mechanism (20) which produces a force against the slide in a press machine using a servo motor (18) as a drive source, comprising force detection means (21) for detecting a force produced between the die cushion and the slide; and comparator means (95) for comparing a force detection value (Fd) detected by the force detection means with a predetermined threshold value (L1); wherein, when the force detection value becomes greater than the threshold value, it is so judged that the slide has come into collision with the die cushion. Thus, the collision is judged within a short period of time and reliably. The collision may be judged by comparing differentiated values (Fd?, Fd?) of the force detection value, slide position detection value (Y1d) or slide position instruction value (Y1c) or other related threshold values.

Abstract: A control device, for a servo die cushion, for precisely performing force control without using a force detector. The control device includes a slide position detecting part for detecting the position of the slide, a storing part for storing information representing a relation between the position of the slide and the speed of the die cushion, the information being predetermined such that the force between the slide and the die cushion is set to a desired force and a die cushion speed commanding part for generating a speed command of the die cushion based on the information and the position of the slide detected by the slide position detecting part.

Abstract: A device for controlling a die cushion mechanism including a servo-motor as a drive source and producing a force adapted to be applied to a slide in a press machine. The device includes a section for commanding a force to be produced by the die cushion mechanism; a section for detecting a force produced by the die cushion mechanism and applied to the slide; a section for detecting a moving speed of the slide; and a section for executing a force control on the servo-motor. The force controlling section executes force controls in mutually different modes on the servo-motor, through mutually different control loops, one mode being provided for an initial stage defined from an instant when the die cushion mechanism starts producing the force to be applied to the slide until a predetermined subsequent instant, and another mode being provided for a succeeding stage defined after the predetermined subsequent instant, by using at least a slide-speed detected value detected by the slide-speed detecting section.