Abstract: A large field-of-view adaptive optics retinal imaging system and method with common optical path beam scanning, the system comprises: a light source module (1), an adaptive optics module (2), a beam scanning module (3), a defocus compensation module (4), a sight beacon module (6), a pupil monitoring module (7), a detection module (8), a control module (9) and an output module (10). The beam scanning module is configured in different scanning modes for carrying out different scanning imaging functions including a large field-of-view imaging function, a small field-of-view high-resolution imaging function and a large field-of-view high-resolution imaging function. The system is simple in structure, and the common optical path structure can obtain three types of retinal imaging images, which meets the requirements of different application scenarios and improves the application range of retinal imaging.

Abstract: An illumination device, an LED driver circuit, a bleeder control circuit and a control method are provided. An AC input voltage is transmitted to a bus line after phase-cut processing. The bleeder control circuit includes a timing module configured to receive a bus voltage and at least one threshold voltage and generate a first time signal; a time processing module configured to receive the first time signal and generate a second time signal based on the first time signal in a previous power frequency half-wave cycle; and a control signal generation module configured to receive the second time signal and generate a first control signal for controlling a bleeder circuit. The beneficial effects of the present disclosure include the bleeder circuit being accurately controlled through the detection of the bus voltage and the implementation of the adaptive control method, thereby improving the operational efficiency and stability of the system.

Abstract: A leakage protection circuit and a dimming drive circuit are provided. A leakage detection circuit is configured to detect whether leakage occurs between two input terminals that receive an external signal. When leakage occurs, leakage protection measures are taken. A pulse generation circuit receives the sampling signal characterizing the voltage between the two input terminals to compare the sampling signal with two thresholds to control a detection path of the leakage detection circuit to be turned on or off according to a comparison result. The leakage detection path is enabled to be turned on twice by setting two pulse signals in a power frequency period, which can consider the leakage detection of the front-edge phase-cutting dimming and rear-edge phase-cutting dimming of the dimming drive circuit and has a wide range of applications.

Abstract: A buffer circuit for an LED driver circuit, a LED driver circuit, and a control method, the buffer circuit includes a first control switch connected in series in a rectified input loop and a feedback control module connected to the rectified input loop to obtain a loop current in the rectified input loop for generating a first control signal to the first control switch according to the loop current and a reference signal. The first control switch switches between a fully conducting state and a non-fully-conducting state based on the first control signal and restrains the loop current when the first control switch is in the non-fully-conducting state. The buffer circuit enhances the effect of restraining the current change rate and can effectively restrain current spikes in a circuit, resulting in higher safety and reliability.

Abstract: An illumination device, an LED driver circuit, a bleeder control circuit and a control method are provided. An AC input voltage is transmitted to a bus line after phase-cut processing. The bleeder control circuit includes a timing module configured to receive a bus voltage and at least one threshold voltage and generate a first time signal; a time processing module configured to receive the first time signal and generate a second time signal based on the first time signal in a previous power frequency half-wave cycle; and a control signal generation module configured to receive the second time signal and generate a first control signal for controlling a bleeder circuit. The beneficial effects of the present disclosure include the bleeder circuit being accurately controlled through the detection of the bus voltage and the implementation of the adaptive control method, thereby improving the operational efficiency and stability of the system.

Abstract: A buffer circuit for an LED driver circuit, a LED driver circuit, and a control method, the buffer circuit includes a first control switch connected in series in a rectified input loop and a feedback control module connected to the rectified input loop to obtain a loop current in the rectified input loop for generating a first control signal to the first control switch according to the loop current and a reference signal. The first control switch switches between a fully conducting state and a non-fully-conducting state based on the first control signal and restrains the loop current when the first control switch is in the non-fully-conducting state. The buffer circuit enhances the effect of restraining the current change rate and can effectively restrain current spikes in a circuit, resulting in higher safety and reliability.

Abstract: A leakage protection circuit and a dimming drive circuit are provided. A leakage detection circuit is configured to detect whether leakage occurs between two input terminals that receive an external signal. When leakage occurs, leakage protection measures are taken. A pulse generation circuit receives the sampling signal characterizing the voltage between the two input terminals to compare the sampling signal with two thresholds to control a detection path of the leakage detection circuit to be turned on or off according to a comparison result. The leakage detection path is enabled to be turned on twice by setting two pulse signals in a power frequency period, which can consider the leakage detection of the front-edge phase-cutting dimming and rear-edge phase-cutting dimming of the dimming drive circuit and has a wide range of applications.