43 results about "Delta wave sleep" patented technology

The invention discloses a human body fatigue evaluation method based on brain waves. According to the method, a ThinkGearAM electroencephalogram chip is used for acquiring original brain wave signals, an built-in algorithm is used for analyzing and processing the original brain wave signals, and four kinds of parameters are given through calculation according to processed brain wave data; the four kinds of parameters include variable coefficients of five brain wave signals of original delta waves, original theta waves, original alpha waves, original beta waves and original gamma waves, two nonlinear parameters of complexity and power spectral entropy, a fatigue index F worked out through energy of four basic rhythms of the delta waves, the theta waves, the alpha waves and the beta waves in the brain waves, and two parameters of relaxation degree and attention degree extracted through the brain wave signals, and the four kinds of parameters serve as input of a probabilistic neural network (PPN), the output of the PNN serves as a human body fatigue evaluation basis, and therefore the human body fatigue can be judged according to the brain waves of people.

Disclosed is an electroencephalogram signal processing method and device. Acquired electroencephalogram signals are subjected to amplification preprocessing, Kaiser Window processing is performed on digital electroencephalogram signals including alpha wave, beta wave, theta wave and delta wave, and index parameters of the electroencephalogram signals are obtained through amplitude analysis, time domain analysis and frequency domain analysis. The electroencephalogram signal processing device comprises an electrode sensor, a preprocessing device, an analog / digital (A / D) conversion unit, a digital signal processing unit, an output unit, a display control unit and a storage unit. The electroencephalogram signal processing device is combined with a computer software analyzing and processing device, and human-machine operation is utilized to achieve functions of result display, healthcare advice, voice prompt and the like. The electroencephalogram signal processing device is convenient, easy to use, low in cost, maintenance-free and capable of conveniently displaying the current mental state and electroencephalogram in real time for students, white-collar employees and mental workers.

A vehicle collision avoidance radar multi-target frequency matching method based on a combined waveform of an LFM triangular wave and a constant frequency wave belongs to the field of vehicle collision avoidance radar multi-target frequency matching, solves the technical problem of multi-target frequency matching, and eliminates constant false alarms. According to the technical scheme, over-threshold detection is carried out on upper and lower frequency sweep segments of the triangular wave and the constant frequency wave separately; beat frequencies of the upper and lower frequency sweep segments of the triangular wave are combined pair-wise and two matrices (A1 and B1) are generated; a difference matrix C1 of the matrix A1 and a first Doppler frequency value detected from the constant frequency wave is calculated, and the minimal value of the matrix C1 is found; and corresponding Doppler frequency values and beat frequencies and values in the matrix A1 and the matrix B1 are output. The beneficial effects are that the technical problem of multi-target frequency matching is solved and false alarms are removed.

The invention relates to a relation model between driver fatigue and vehicle driving track, and belongs to the field of transportation. Aiming at fatigue driving early warning application background, by simulating a driving fatigue sampling test of a human-vehicle-road (environment) system in a constructed semi-physical virtual traffic environment, adopting percentage of delta waves and theta waves in facial expression and brain waves of a driver as a standard for judging fatigue degree of the driver, and adopting a method combining time domain analysis and mathematical statistics analysis, the invention researches and determines periodic decreasing driving fatigue preliminary early warning rules of the track of a right front wheel of a vehicle from a right lane line and driving fatigue judgment limit of offset variance of the lane line, can judge fatigue characteristics or moderate fatigue state of the driver, and also researches and determines serious fatigue driving warning rules of abnormal vehicle lane changing. A driving fatigue recognition and early warning system based on the vehicle running track can be established by the invention.

The invention relates to a method and a system for processing electroencephalogram for monitoring sleeping state. The method comprises the following steps: collecting the electroencephalogram generated in the sleeping process of a user; performing wavelet decomposition on the electroencephalogram, regulating wavelet coefficient after decomposition and filtering the noise; extracting a delta wave frequency band, a theta wave frequency band, an alpha wave frequency band and a beta wave frequency band of the electroencephalogram in wavelet reconstruction and respectively calculating the characteristic quantity of the delta wave frequency band, the theta wave frequency band, the alpha wave frequency band and the beta wave frequency band; confirming the characteristic information corresponding to the type of the sleeping state recognition task according to the characteristic quantity of the delta wave frequency band, the theta wave frequency band, the alpha wave frequency band and the beta wave frequency band. On the basis of the technical scheme provided by the invention, the filtering and noise reduction are realized in wavelet decomposition, the characteristic quantity calculation is realized in wavelet reconstruction and the processing efficiency of the electroencephalogram is increased.

The invention discloses an intelligent sleep aid system based on electroencephalogram monitoring and a sleep headphone thereof, and belongs to the field of intelligent sleep aid. According to the intelligent sleep aid system, on the basis of monitoring the electroencephalogram situation when a user sleeps, electroencephalogram signals are collected, and the electroencephalogram signals are specially classified; the energy ratio of beta wave to alpha wave to theta wave to delta wave serves as a characteristic value, incremental learning is conducted by using a support vector machine, the sleepof the user is staged, and while the classification accuracy is ensured, the time complexity of a sleep staging algorithm is reduced as much as possible. The sleep headphone of the intelligent sleep aid system can accurately and effectively achieve staging, according to requirements of different users, the music type of the headphone can be set, the volume size can be adjusted, so that the electroencephalogram (EEG) of the user enters a deep sleep stage or a REM stage, that is, the user enters the optimal sleep state.

The present invention relates to a portable brainwave measuring method, which measures a weak brainwave signal detected from a human scalp through a noninvasive method to measure a degree of concentration through an analysis and process of the detected brainwave signal, and a control method enabled for short distance control of an electronic device or remote monitoring through the internet, by using the brainwave signal. An acceleration sensor is put on the head of a user, and a brainwave detecting means put on the head of a user to detect a brainwave and the acceleration sensor that outputs an acceleration value of three axes including XYZ axes as a signal of predetermined data are used to detect movement of the head, to thereby control the direction and speed of a brainwave-related device.; In more detail, after a signal outputted from the brainwave detecting means is converted into a wireless signal and transmitted, a value of the wireless signal is inputted to a receiving unit of a display device and is expressed numerically. By setting the value inputted to the display device, a portable brainwave measuring device provides accurate device control. A control system is characterized in that a signal according to the slope direction of the head is detected and analyzed, and then numerically expressed by using 6 brainwave signals such as a delta wave (delta), theta wave (theta), alpha wave (alpha), SMR wave, beta wave (beta) and gamma wave (sigma), which are measured through the portable brainwave measuring device and the acceleration sensor put on the head. A wireless system, including a short distance wireless module for transmitting / receiving the wireless signal, includes a wireless receiving module, a signal analyzing unit, and a control output unit. Additionally, the wireless system is connected to a PC or controls a short / long distance external device.

The invention relates to the field of bedding articles, in particular to a sleep-aiding pillow and a sleep-aiding method. The sleep-aiding pillow comprises a pillow body, wherein the pillow body is connected with a plurality of brain wave detection electrodes; a timer is fixedly mounted on the pillow body; a controller and a loudspeaker are arranged in the interior of the pillow body; the controller is used for controlling the connection of the brain wave detection electrodes, the timer and the loudspeaker by a signal wire. According to the sleep-aiding pillow, the brain wave detection electrodes are arranged on the sleep-aiding pillow; delta wave capable of enabling the user to deeply sleep is sent by the loudspeaker when the fact that the user generates the brain wave corresponding to hazy sleepiness or light sleep state is detected; the user brain wave resonates with the delta wave, so that the sleep quality is improved.

The invention discloses a hypnosis music playing method and system based on a television and the television. The hypnosis music playing method based on the television comprises the following steps that an audio file is stored in the television in advance, wherein the frequency spectrum and the frequency of the audio file are identical to those of the alpha wave of brain waves; an audio file is stored in the television in advance, wherein the frequency spectrum and the frequency of the audio file are identical to those of the delta wave of the brain waves; when the hypnosis function is needed, the audio file with the frequency spectrum identical to that of the alpha wave of the brain waves and the frequency identical to that of the alpha wave of the brain waves is controlled to be played by the television, so that the alpha wave is generated, after a preset period, the audio file with the frequency spectrum identical to that of the delta wave of the brain waves and the frequency being identical to that of the delta wave of the brain waves is controlled to the played by the television, so that the delta wave is generated, physical resonance is caused by sound wave vibration, the body and the mind of a user are made to be relaxed under the intervention of the alpha wave, the user is guided to enter the asleep state by the delta wave, and the excited mood of the user is rapidly relieved. Due to the fact that the hypnosis music playing method is achieved in the television through software, cost is low and the hypnosis music playing method is easy to achieve.

A portable therapeutic field generator device (10) generates a reduced magnetic field component for a relatively large electric field by virtue that adjacent conductive tracks in a radiating element (40, 50) conduct electrical current in opposing directions. The device (10) includes a processor (12) that, in response to a control algorithm stored in memory (14), supplies a pulse wave (22) to a circuit containing the radiating element (40, 50). The pulse establishes generation of a base heartbeat reference having a frequency around a nominal heart rate. At periodic times, the base heart beat reference is supplemented by mutually exclusive periods of alpha wave, theta wave and delta wave generation (or other selected frequencies below about 200 Hz) based on selected brainwave frequencies for these waves, with the pulses having a duration generally corresponding to that ascribed to neuron depolarisation pulses. The device (10) cycles through multiple cycles (88) and, dependent upon the effect that is desired, may see delta wave frequencies follow theta wave frequencies that follow alpha wave frequencies. Delays may exist between transitions between the generated waves, with delta wave generation occurring no later than sixty minutes from commencement of alpha wave production for a mode that induces sleep. Delta waves production has, typically, a duration that is twice that of either the alpha or theta wave production. A second mode of operation sees longer pulse times for higher frequencies—between about 100 Hz and 500 Hz—associated with muscle stimulation.

The invention relates to a sleep cycle detection method and a sleep cycle detection system in sleep state analysis. The method comprises the following steps of: performing wavelet decomposition for electroencephalogram generated during the sleep process of a user, rebuilding electroencephalogram according to a preset wavelet coefficient of a low frequency band, and obtaining low-frequency electroencephalogram; extracting a brain wave from the rebuilt low-frequency electroencephalogram; detecting a K comprehensive wave in the brain wave according to a waveform characteristic of the K comprehensive wave, and when the K comprehensive wave is detected, determining that the user currently stays at a cycle S2 of non-rapid eye movement sleep; detecting a delta wave from the brain wave according to the waveform characteristic of the delta wave, and counting the number of the detected delta waves; and determining cycles S3 and S4 of non-rapid eye movement sleep of the user according to the number of the delta waves. By adopting the technical scheme, the electroencephalogram can be prevented from being interfered, whether the user currently stays at a cycle S2 to S4 of the non-rapid eye movement of the user can be accurately detected, and the accuracy is higher.

The invention discloses a wearable electroencephalogram sleeping quality evaluator. A virtual screen is generated at a position which is two meters away from a human eye by a portable projector, and video simulating signals are provided for sleeping quality evaluation. Audio signals are outputted by an audio interface, and audio simulating signals such as background music and training instructions are provided for sleeping quality evaluation. Electroencephalogram electrodes are placed at the forehead of a brain by the aid of a rotary adjusting rod and a telescopic adjusting rod. The electroencephalogram electrodes transmit acquired brain wave signals into an embedded processing unit, the embedded processing unit performs spectral analysis for the brain wave signals, delta wave components reflecting the sleeping state of the brain are extracted, neural feedback is performed for sleeping quality evaluation, and data are transmitted to a man-machine interaction device through a wireless data interface. Electroencephalograms are used as feedback signals of sleeping quality evaluation, and sleeping quality evaluation efficiency and reliability are greatly improved. By the aid of a wearable computer, many unnecessary interference factors are eliminated, and a training environment is improved.

The invention belongs to the technical field of information processing, and discloses an intelligent sleep and fatigue state information monitoring control system and method and a monitor. An electroencephalogram module is used for collecting electroencephalogram signals; fourier transform is carried out on the collected signals, and energy proportions of alpha waves, beta waves, theta waves and delta waves are analyzed to judge the sleep state or fatigue degree of the user; a white noise emitting module is used for emitting white noise to improve the sleep state when the user is in the mild sleep state; a heart rate monitoring module measures pulse waves through a photoplethysmography method and detects the real-time heart rate. The sleep quality or fatigue state of the user can be obtained through analysis by monitoring the brain wave data of the user, and meanwhile the real-time heart rate of the user is monitored. When it is found that the user is in a light sleep state, the systemautomatically plays white noise to improve sleep quality of the user; and when the user enters deep sleep, the white noise stops. When the user is found to be in a deep fatigue state, alarm sound canbe emitted to remind the user to have a rest timely.

The invention relates to marking equipment for the data type of electroencephalogram signals in a sleeping state, comprising an electroencephalogram electrode, a reference electrode, an analog-digital converter, a filter circuit and a processor, wherein the electroencephalogram electrode and the reference electrode are respectively connected with the analog-digital converter and sequentially connected to the processor through the analog-digital converter and the filter circuit; the electroencephalogram electrode is used for detecting electroencephalogram signals of a user in sleeping; the analog-digital converter converts the electroencephalogram signals into digital signals; the filter circuit carries out low-frequency filtration on the electroencephalogram signals and then inputs into the processor; the processor is used for carrying out wavelet decomposition on the electroencephalogram signal sample, reconstructing low-frequency electroencephalogram signals, and extracting brain waves from the low-frequency electroencephalogram signals; detecting K complex waves and delta waves from the brain waves and counting the number; and when the number exceeds a preset number threshold, marking the data type of the electroencephalogram signal sample as sleeping. The marking equipment for the data type of electroencephalogram signals in a sleeping state can eliminate interference components mixed in the electroencephalogram signal sample and have higher marking accuracy.

The invention discloses a Chinese medicine directional sleep instrument, which comprises a sleeping pillow / cushion, an electromagnetic wave generator, and a far infrared thermal energy module, wherein the sleeping pillow / cushion comprises a sleeping pillow / cushion base; the electromagnetic wave generator is composed of permanent magnets and electromagnets for generating an alternating magnetic field; the far infrared thermal energy module is composed of heating cushion filled with carbon fiber heating wires; the electromagnetic wave generator is arranged inside or on the outer surface of the sleeping pillow / cushion base; and the heating cushion is laid in the sleeping pillow / cushion. According to the Chinese medicine directional sleep instrument, the far infrared thermal energy module and the electromagnetic wave generator are arranged at the same time, the far infrared thermal energy module can provide comfortable sleeping warm feeling, microcirculation of a human body can be adjusted, the electromagnetic wave generator generates a biological magnetic field most suitable for the human body, blood circulation of the human body can be improved, the interactive function between the two function units can reach effects of smoothening meridians, increasing blood and oxygen supply of the brain, and reducing terminal nerve excitability of brain, generation of delta waves in the case of sleeping of the human body is promoted, and insomnia symptoms are improved.

The present invention provides a bionic sleep biological rhythm alarm clock. The bionic sleep biological rhythm alarm clock employs light simulation with special frequency to induce people in sleep tobe always weaken up in a light sleep period according to a brain electrical rhythm synchronization effect, and finally, an effect of simulation of natural wakeup is achieved. A deep sleep period takes Delta waves as main waves, and the light sleep period takes Theta waves as main waves. When light simulation with a frequency range of 3-8Hz is acted on a brain, brain wave frequencies can be changed from an original frequency range to a simulation frequency range. Therefore, people in sleep are induced by employing the light simulation with special frequency to allow the people who are waken upto be still in the light sleep period so as to eliminate people's fatigue feeling such as dizzy and sleepy and the like. According to the brain electrical rhythm synchronization effect, the bionic sleep biological rhythm alarm clock can simulate a nature awakening state through light induction, can induce the people in sleep to be waken up in the light sleep period to allow the people to be fullof energy when the people are waken up without any fatigue feeling.

The invention provides a vital sign wireless monitoring method based on waveform design and reflected wave treatment, and belongs to the technical field of medical health and information. According tothe method, wireless monitoring equipment based on a reflected wave of a human body has the capacity of synchronously monitoring vital signs of a plurality of human bodies. The method utilizes changes of phase information of the reflected wave of the human body which are caused by heartbeat of the human body and the respiratory vital sign for dividing a difference frequency signal of the reflected wave and a transmitting wave into a short frame structure and a long frame structure by transmitting a wireless electric wave with the frequency changing with a triangular wave and extracting and analyzing change laws of initial phases of transmitting waves of different human bodies to estimate the heart rate and respiratory rate of each human body. According to the method, the signal treatmentsoft operation is conducted on existing wireless monitoring equipment to have the capacity of monitoring multiple people. The method has a good application prospect in the fields of medical monitoring, old people and child monitoring, health state monitoring and the like.

The invention belongs to the technical field of integrated circuit design and biomedical combination, and discloses a deep sleep improvement detection system and method based on a biological low noiseamplifier. The method includes that before the human body sleeps, a detecting device is worn on the head; a bioelectrode in the detecting device samples an EEG signal which is subjected to amplification treatment by an analog front end like the biological low noise amplifier to form an EEG spectrogram; the computer technology of the device is utilized to analyze the spectral characteristics of the EEG; when a delta wave (a long pulse wave released by the brain during the deep sleep) is detected, the device automatically plays sound of some corresponding bands, diffracting more delta bands topromote the deep sleep. The biological low noise amplifier is utilized to amplify and process the extracted EEG signal, analyze the sleep state give certain improvement, prolong the deep sleep time and improves the physiological state. Compared with the traditional EEG spectrum application, the system no longer only observes the human brain activity artificially and by computer-analyzed spectrum,but is directly applied to the improvement of sleep and put into action.

The invention discloses a psychological state judgment method based on EEG energy clustering analysis, and a corresponding system thereof. The method comprises the following steps: (10) EEG collection: collecting EEGs under different psychological emotional states; (20) signal preprocessing: preprocessing the EEG; (30) energy data acquisition: computing the energy of the delta wave, the theta wave, alpha wave and beta wave in the specific psychological states; (40) energy clustering center computation under different psychologies: computing the EEG energy clustering centers under different psychological emotional states through the clustering analysis algorithm; (50) current psychology energy computation: collecting the EEG under the current psychological emotional state and computing theEEG energy; (60) current phycology judgment: computing the distance between the current EEG energy and the EEG energy clustering center, and judging the current psychological emotional state. Throughthe psychological state judgment method and system disclosed by the invention, the psychological state can be accurately judged by determining the quantitative state of the EEG and the psychological state.

The invention relates to a sleeping state detection method and system in sleeping state analysis, wherein the method comprises the steps: carrying out wavelet decomposition on electroencephalogram signals generated by a user in the sleeping process, and reconstructing the electroencephalogram signals according to a preset wavelet coefficient in a low-frequency stage to obtain low-frequency electroencephalogram signals; extracting brain waves from the reconstructed low-frequency electroencephalogram signals; according to the wave characters of K complex waves and delta waves, detecting the K complex waves and delta waves in the brain waves; and counting the number of the K complex waves and delta waves detected, and when the number exceeds a preset number threshold, judging that the user is in the sleeping state currently. The technique disclosed by the invention can prevent electroencephalogram signals from being interfered and influencing the detection result, thereby having higher accuracy rate.

The invention discloses a wearable electroencephalogram sleeping quality evaluator. A virtual screen is generated at a position which is two meters away from a human eye by a portable projector, and video simulating signals are provided for sleeping quality evaluation. Audio signals are outputted by an audio interface, and audio simulating signals such as background music and training instructions are provided for sleeping quality evaluation. Electroencephalogram electrodes are placed at the forehead of a brain by the aid of a rotary adjusting rod and a telescopic adjusting rod. The electroencephalogram electrodes transmit acquired brain wave signals into an embedded processing unit, the embedded processing unit performs spectral analysis for the brain wave signals, delta wave components reflecting the sleeping state of the brain are extracted, neural feedback is performed for sleeping quality evaluation, and data are transmitted to a man-machine interaction device through a wireless data interface. Electroencephalograms are used as feedback signals of sleeping quality evaluation, and sleeping quality evaluation efficiency and reliability are greatly improved. By the aid of a wearable computer, many unnecessary interference factors are eliminated, and a training environment is improved.

The invention is concerned with microcomputer zoology curing equipment, relating to a kind of electromagnetism medical treatment health protection equipment to solve the problem that the existing curing equipment is not convenient for complex operation. It relates to power supply, display, key-press and electromagnetism loop. The power supply connects with single chip, amplifier and liquid crystal display, and the single chip connects with liquid crystal display, key-press and amplifier which connecting with electromagnetism loop, and the time actuator; connects with power supply and single chip. The said electromagnetism loop can produce one or some kind of 0.4 to 4Hz delta wave, 4 to 8 Hz theta wave, 9 to 13 Hz alpha wave, or 14 to 22 Hz beta wave. The curing equipment does not touch the people body with small bulk and easy operation, and it produces a space magnetic field with small range to communicate with the electromagnetism field of people body to take effect and keep the balance of the electromagnetism field of people body and cure the illness. It is fit for people in all kinds of age.

The invention discloses a method for making variable-frequency-difference sleep-aiding double-frequency music, and relates to the technical field of music therapy. The method comprises the following steps of making double-frequency music with four different frequency differences of Beta, Alpha, Theta and Delta, wherein each time period is 15 minutes; mixing the four different frequency differenceswith background music; connecting the four pieces of double-frequency music with the background music to synthesize 60-minute variable-frequency double-frequency music; outputting the synthesized double-frequency music with the background music; and during output, selecting a Wave waveform format for storage, and then converting the Wave waveform format into an MP3 format or other formats. By means of the variable-frequency double-frequency music technology, brain waves of a user can be effectively induced to enter Theta waves of light sleep from Beta waves in a waking state and then enter Delta waves of deep sleep; and great help is provided for hypnosis, auxiliary treatment of refractory insomnia and correction of brain wave Delta frequency disorder of patients with melancholia.

The invention relates to a method and system for labeling the type of electroencephalographic signal data in a sleep state. The method includes the steps that wavelet decomposition is carried out on an electroencephalographic signal sample, an electroencephalographic signal is reconstructed according to a preset wavelet coefficient in a low-frequency stage, and a low-frequency electroencephalographic signal is obtained; brain waves are extracted from the reconstructed low-frequency electroencephalographic signal; K synthetic waves and delta waves are detected from the brain waves according to the waveform characteristics of the K synthetic waves and the delta waves; the number of the detected K synthetic waves and delta waves is calculated, and when the number exceeds a preset number threshold value, the signal type of the electroencephalographic signal sample is labeled as sleep. By labeling the type of the electroencephalographic signal sample according to the technical scheme, interference elements mixed into the electroencephalographic signal sample can be eliminated, so that a personal classifier trained with the labeled electroencephalographic signal sample is higher in recognition accuracy rate, and the reliability of the detection result of the personal sleep state detected in a later stage is improved.

Disclosed are methods and devices for modulating delta brainwaves in a sleeping subject. In various embodiments, the method includes a) detecting and monitoring an initial delta wave in a subject, b) applying an electrical current to modulate the initial delta wave in the subject, thereby modifying the initial delta wave in the subject to form a modified delta wave, and, optionally, repeating cycles of steps a) and b), thereby modulating delta brainwaves.

The invention discloses a triangular wave modulation photoelectric plethysmography measurement device and method capable of raising an electrical level. A micro processor outputs triangular waves which have different frequencies and raise a preset electrical level in a twice-proportion relation to drive at least four light emitting diodes; light emitted by the light emitting diodes is received by a photosensor after passing through a measured finger; the photosensor converts the light into a voltage signal; the voltage signal is converted into a preset amplitude voltage signal through a current / voltage conversion amplifier; the micro processor processes a digital signal to acquire photoelectric plethysmography as well as a valley value and a peak value thereof so as to obtain a spectral value; in a process that the photosensor acquires a photoelectric signal, the noise level is not changed, but the preset electrical level of a triangular wave signal serving as a driver is raised, so that the low electrical level part of the triangular wave signal is obviously improved when the triangular wave signal is compared with noise; therefore, the signal-to-noise ratio of a photoelectric signal acquired by the photosensor at the low electrical level part of the triangular wave signal is increased, and the precision of the digital signal input into a computer is improved.

The invention discloses an eye fundus photography control circuit applying triangular wave illumination capable of raising preset level. According to the control circuit, light reflected back from eye fundi of detected human eyes passes through an eyepiece and objective lens a half-transparent and half-reflecting prism and an imaging lens sequentially to be imaged in an image sensor; the image sensor acquires one or more video images in the period of the triangular wave or sawtooth wave and transmits the video images to a computer, gliding frame accumulative average is performed on the video images within the time length, and an eye fundus image signal with higher definition is obtained; during image acquisition of the image sensor, noise level is not changed, but the triangular wave signal as a drive unit is improved remarkably at the low level part compared with noise due to the fact that the preset level is improved, the signal-to-noise ratio, acquired by the image sensor, of the images is increased at the low level section of the triangular wave signal, and accordingly, the precision of the video images input into the computer is improved.