Abstract: A signal analyzing system is provided. The signal analyzing system includes a band pass filter (BPF), a sampling unit and a continuous shifted transform (CST) unit. The BPF filters an input signal to obtain a filtered signal. The sampling unit samples the filtered signal to obtain a discrete signal according to a sampling frequency. The CST unit obtains a first frequency spectrum according to the N discrete signals that are sampled continuously, and obtains a second frequency spectrum according to a (N+1)th discrete signal and the first frequency spectrum. Each of the first and second spectra includes N Fourier transform operation results.

Abstract: An encoder having an oil mist prevention structure includes: an encoding body including a cylindrical base, a light emitter and a secondary encoding piece; an oil-containing bearing received and fixed in the cylindrical base; a shaft penetrating the oil-containing bearing to protrude beyond an end surface of the bearing; a rotary disk fixed onto the shaft to cover one side of the secondary encoding piece; a light acceptor fixed to the cylindrical base to correspond to the light emitter and the secondary encoding piece, thereby receiving the signals emitted by the light emitter; and an oil mist prevention structure including a mask integrally formed with the shaft and exposed beyond an end surface of the bearing and a ring extending from the mask for covering an outer periphery of the bearing.

Abstract: An encoder having an oil mist prevention structure includes: an encoding body including a cylindrical base, a light emitter and a secondary encoding piece; an oil-containing bearing received and fixed in the cylindrical base; a shaft penetrating the oil-containing bearing to protrude beyond an end surface of the bearing; a rotary disk fixed onto the shaft to cover one side of the secondary encoding piece; a light acceptor fixed to the cylindrical base to correspond to the light emitter and the secondary encoding piece, thereby receiving the signals emitted by the light emitter; and an oil mist prevention structure including a mask integrally formed with the shaft and exposed beyond an end surface of the bearing and a ring extending from the mask for covering an outer periphery of the bearing.

Abstract: A servo motor system and an operating method of the servo motor system are disclosed. The servo motor system includes a servo motor and a servo driver. The servo motor is electrically connected to the servo driver. The servo motor includes a motor unit and an encoder. The encoder is mechanically connected to the motor unit. The encoder includes a CPU and a memory unit. The memory unit is electrically connected to the CPU. Data parameters are saved in the memory unit. The servo driver uses data parameters of the motor unit saved in the memory unit for controlling the motor unit. The servo motor system and the operating method provide a mechanism to drive and offer compensation to an upgraded motor.

Abstract: A control system used to control a controlled plant includes a main control unit, a first tuning unit, and a second tuning unit. The control system regulated by two weighting parameters of a first multiple and a second multiple, robustness and rapid response are attained, and excess of the output signal the controlled plant generates disappears or approaches zero. The control system has technical features of objective bandwidth, offsetting of low frequency disturbance, and matching of transfer functions. By designing the main control unit, the first tuning unit, and the second tuning unit, regulating the two weighting parameters of the first multiple and the second multiple, and tuning the actual system, the above technical features are obtained.

Abstract: A liquid crystal displayer for preventing the generation of moisture includes a front cover, a touch panel, a nameplate, a partitioning plate and a liquid crystal displayer module. With the partitioning plate dividing a region between the touch panel and the liquid crystal displayer module into a first space and a second space, the first space is smaller, whereas the second space is larger. After the liquid crystal displayer module is supplied with electricity, the hot air staying in the first space is less. Further, the heat-obstructing effect of the partitioning plate causes the hot air not to condense in the second space, and thus it is not easy to generate a temperature difference from the external environment, thereby preventing the generation of mist.

Abstract: An angle-calculation apparatus for three-phase optical encoder receives three-phase sinusoidal signals 120 degree phase from the optical encoder and obtains angle information for a motor rotor. The angle-calculation apparatus includes an A/D converter, a digital signal processor (DSP), a phase digitalizer and a digital counter. The A/D converter converts three-phase analog signals of the optical encoder into three-phase digital signals. The phase digitalizer converts the three-phase analog signals into digital phase signals. The digital counter generates a counting value based on the digital phase signals. The DSP performs an inverse trigonometric function calculation on a relatively linear region of the three-phase digital signals to obtain the angle information. The DSP obtains the rotation turn number and rotation direction of the motor rotor according to the counting value.

Abstract: A high-precision absolute type encoder apparatus includes a controller electrically connected to an incremental type encoder and generating a control signal to the incremental type encoder, a comparator electrically connected to outputs of the incremental type encoder and generating first pulse signals, a latch unit electrically connected to outputs of the comparator and generating second pulse signals by latching the generating first pulse signals. When power failure occurs, the controller generates the control signal as successive pulses with predetermined period to drive the latch unit and the incremental type encoder. Therefore, the controller knows angular information of the incremental type encoder by counting the second pulse signals. The absolute angular information can be obtained by combining the angular information and an initial position after power failure.

Abstract: An angle-calculation apparatus for three-phase optical encoder receives three-phase sinusoidal signals 120 degree phase from the optical encoder and obtains angle information for a motor rotor. The angle-calculation apparatus includes an A/D converter, a digital signal processor (DSP), a phase digitalizer and a digital counter. The A/D converter converts three-phase analog signals of the optical encoder into three-phase digital signals. The phase digitalizer converts the three-phase analog signals into digital phase signals. The digital counter generates a counting value based on the digital phase signals. The DSP performs an inverse trigonometric function calculation on a relatively linear region of the three-phase digital signals to obtain the angle information. The DSP obtains the rotation turn number and rotation direction of the motor rotor according to the counting value.

Abstract: A liquid crystal displayer for preventing the generation of moisture includes a front cover, a touch panel, a nameplate, a partitioning plate and a liquid crystal displayer module. With the partitioning plate dividing a region between the touch panel and the liquid crystal displayer module into a first space and a second space, the first space is smaller, whereas the second space is larger. After the liquid crystal displayer module is supplied with electricity, the hot air staying in the first space is less. Further, the heat-obstructing effect of the partitioning plate causes the hot air not to condense in the second space, and thus it is not easy to generate a temperature difference from the external environment, thereby preventing the generation of mist.

Abstract: An AC servo drive without current sensor includes a PI (proportional integration) controller, at least two first-order controllers (polar point and zero point), a decoupling compensator, a coordinate converter, a pulse width modulator, a counter and a speed estimator. The AC servo drive is connected with a servomotor to form an AC servo module. The servomotor comprises an encoder receiving a current command signal from the servo module to function as input current command signal or the d, q axes PI controller and the decoupling compensator. The voltage command signal generated by the d, q axes PI controller and the signal generated by the decoupling compensator form a control signal and input to the coordinate converter. The signal output from the coordinate converter is processed by PWM controller to control the servomotor. Therefore, the deterioration of servo motor control caused by temperature drift and cost can be solved.

Abstract: An AC servo system with distributed movement control is used for multiple axes control in distributed manner includes at least one drive containing a programmable movement controller to perform a customized procedure to control I/O signal of local axis or other axis. The drive can download/perform movement program through communication network, edit axis parameter and monitor the axis status. The drive can set to be master/slave axis according to practical need. The master axis drive performs multiple axes simultaneous control and sends path command to each slave axis drive. The master axis drive calculates complementary command coordinate according to the path command and the path command received by the slave axis drive, whereby the movement trace of the master/slave axis drive can satisfy the path command requirement.

Abstract: The present invention provides a method for guiding a pick-up head to follow an information track. The method comprises the steps of sensing and sending notification of displacement between the pick-up head and the center of the information track, generating a first correction directly proportional to the displacement, generating from the first correction a second correction non-proportional to the displacement, generating a third correction from an amplified tracking error signal and generating a driving force proportional to the sum of the second and third corrections, driving the pick-up head to follow the information track.

Abstract: A robust current loop controller for a servo system is provided. The robust current loop controller includes a model reference controller and a current controller. The model reference controller generates a velocity command signal from a current command reference signal of the servo system and generates a current command signal through comparing the velocity command signal with a feedback velocity command signal of the servo system. The current controller generates a control signal from the current command signal, the current command reference signal and a current feedback signal in order to drive the servo system.

Abstract: The invention provides a method for improving the yield of a CD recorder, adjusting the current recordable rate and a write delay table using the data of a write radio frequency profile.

Abstract: The present invention provides a method for guiding a pick-up head to follow an information track. The method comprises the steps of sensing and sending notification of displacement between the pick-up head and the center of the information track, generating a first correction directly proportional to the displacement, generating a second correction non-proportional to the displacement and generating a driving force proportional to the sum of the first and second correction, driving the pick-up head to follow the information track.

Abstract: Disclosed is a high-speed dynamic actuating system for optical disks, particularly useful in an optical disk drive, wherein a closed-loop approach is used to overcome the diversity between devices and thus meet the requirement for high speed track-accessing and solve the problems in that the convention open-loop track-jumping takes a long period of time to perform segmental adjustment. The pick-up head is activated by applying high-speed dynamic actuation of the lens so as to conform to the pre-determined velocity curve and eliminate the wobble of the lens caused by different track-jumping times in an optical disk drive and a hard disk. In addition, said system can be implemented in an integrated circuit (IC), which is directly controlled by the hardware and thus effectively simplifies the complicated configuration as in the prior art.

Abstract: Disclosed is a pick-up head controller for optical disk drives, structured particularly for optimal actuation characteristics of a pick-up head of optical disk drives. A framework, composed of a high-frequency digital controller and a low-frequency digital controller, accomplishing different order types of controllers required by optical head systems, is provided based upon the sampling rate dependence of response of digital controllers. Experimental results shows excellent performance in optical systems that high performance, low cost and easy designing can be achieved.