Abstract: Provided are a computer system having a security function, a computer security method, and an optical pointing device. The optical pointing device includes: an optical part irradiating light to a worktable surface and transmitting the light reflected; receiving the reflected light to continuously detect an image and detect a motion of the optical pointing device using variation of the image, and calculating a motion value to output motion data; a first transparent plate receiving the reflected light to discharge the light to the exterior; a second transparent plate transmitting the light discharged and reflected from the subject into the optical pointing device; a subject motion sensor receiving the light reflected from the subject to detect a motion of the subject, and outputting subject motion data; and a motion data storage part storing the motion data and the subject motion data.

Abstract: The present invention relates to an optical pointing system and a method for calculating a movement value thereof, comprising: an image sensor for detecting light reflected from a worktable surface to generate an image signal, a maximum search window variable circuit for inputting at least one of the image signal and a movement value to change a size of a maximum search window, and a movement value calculation circuit for calculating the movement value of the image signal using the maximum search window with the changed size. Therefore, an exact movement value can be found by changing at least one of the maximum search window and a sampling rate according to at least one of a quantity of light and a movement speed to calculate the movement value.

Abstract: Disclosed is an optical mouse and method for preventing abnormal operation of the same. The method comprises the steps of (a) when a shutter-on time of an image sensor is continuously increased or decreased, obtaining a plurality of frames for the shutter-on time, and (b) calculating and outputting a movement value of the optical mouse using one frame obtaining a surface image with the highest accuracy from among the plurality of frames obtained in the step (a). Thus, by sensing the time when the optical mouse passes through an interface having an obvious difference in brightness and preventing the wrong movement value from being outputted, it is possible to prevent the abnormal operation of the optical mouse.

Abstract: The present invention discloses a method of calculating sub-pixel movement and a position tracking sensor using the same. The method includes: setting a reference frame and receiving a current surface image illuminated by light as a sample frame; calculating correlation between the reference frame and the sample frame to obtain a movement value; when the calculated movement value is above a first value, updating the reference frame to the sample frame, and when above a second value, recognizing a movement value of the sample frame with respect to the reference frame; and calculating the movement value of the sample frame with respect to an auxiliary reference frame, and updating the auxiliary reference frame to the sample frame in association with the movement calculation of the sample frame to the reference frame, and when the calculated movement value is above a third value, recognizing the movement value of the sample frame with respect to the auxiliary reference frame.

Abstract: Disclosed is a method for calculating a movement value of an optical mouse and an optical mouse using it. The method comprises the steps of: adjusting a reference frame update speed based on a movement speed of the optical mouse and updating the reference frame, calculating a first movement value, wherein the step of calculating the first movement value sets a reference area in the updated reference frame, and finds a correlation between a current input frame and the reference area of the reference frame to calculate the movement value, and resetting a reference area, wherein the step of resetting a reference area sets a new reference frame to which the reference area of the reference frame is moved by considering the calculated movement value according to the adjusted reference frame update speed.

Abstract: A photocurrent sensing circuit having a stabilized feedback loop comprises a photocurrent generator including a photodiode generating the photocurrent in proportion to an amount of incident light and applying the photocurrent to an output node, a switching unit applying the photocurrent applied to a control node to a voltage-generating capacitor when a shutter signal is in a first state, and applying a predetermined current to the control node when the shutter signal is in a second state, and a circuit stabilizer applying the photocurrent applied to the output node to the control node, and always forming a feedback loop of the photodiode through the photocurrent applied to the output node, wherein the circuit stabilizer comprises a first NMOS transistor forming the feedback loop of the photodiode in response to the photocurrent input to the output node when the predetermined current is applied to the control node, breaking the feedback loop and applying the photocurrent applied to the output node to the contr

Abstract: Disclosed is an optical mouse comprising an image sensor, consisted of a plurality of pixels, for outputting signals accumulated in a given time as a pixel unit, an A/D converter, an image data calculating a moving value of the optical mouse, a system controller for controlling a data flow with an external system, an average value calculator calculating an average value, and a pick-up state discriminator for generating a pick-up state signal. In addition, the optical mouse further comprises a fluorescent lamp state discriminator for discriminating whether the optical mouse is in a fluorescent lamp state and generating a fluorescent lamp state signal.

Abstract: Disclosed is an optical image detector and method for controlling illumination of the same. The optical image detector comprises a light source for controlling the illumination in response to an illumination control signal and irradiating light having the controlled illumination onto a subject, an image sensor for detecting a quantity of light reflected from the subject and generating and outputting image signals corresponding to the detected quantity of light, and an image processor for calculating a shutter-on time using the image signals, comparing the calculated shutter-on time with at least one of maximum and minimum shutter-on times, and generating and outputting the illumination control signal corresponding to values of the compared results.

Abstract: Disclosed is a semiconductor device comprising a reference circuit for receiving a plurality of impedance control signals and generating a reference voltage, a transmission driving circuit for receiving the impedance control signals and a pair of differential input signals and outputting a pair of differential output signals to an external cable, and an impedance control signal generating circuit for receiving a difference signal of the differential output signals and the reference voltage and generating the impedance control signals.

Abstract: An optical mouse of a dynamic range has an analog/digital (A/D) converter having an input range adjusted based on an input range control signal, the A/D converter receiving an input signal over the adjusted input range and converting the received signal into digital data, and an image data processor for determining on the basis of image data from the A/D converter whether a data concentrated distribution has occurred, detecting a level of the input range with the data concentrated distribution upon determining that the data concentrated distribution has occurred, outputting the input range control signal to the A/D converter according to the detected level and processing the image data from the A/D converter to detect motion data therefrom.