Abstract: A detection method for stain on a light cover of a LiDAR, including: transmitting a multi-pulse sequence with pulse coding; receiving an echo; obtaining an echo pulse sequence in the echo corresponding to the multi-pulse sequence; determining whether the light cover of the LiDAR has a stain based on a time of flight (TOF) of the echo pulse sequence. The present disclosure utilizes light beams generated by a transmitter unit of the LiDAR to detect a stain on the light cover, without the necessity to add an extra light source and/or detector device. The present disclosure provides a simple structure, which saves internal space of the LiDAR. In this application, the detection is completed by using the coded time, TOF and the number of echo points, and the detection accuracy is high and the misjudgment can be avoided.

Abstract: Disclosed is a pixel circuit arranged in a display substrate, which comprises a first driving mode and a second driving mode. Content displayed in the display substrate comprises multiple display frames. In the first driving mode and the second driving mode, the display frames comprise refresh frames. A signal of a second scanning line is the same as that of a third scanning line. The time of which the signal of the second scanning line is an active level signal comprises a first refresh time period, a second refresh time period and a third refresh time period, which sequentially occur at intervals. During the second refresh time period, a signal of a first scanning line is an inactive level signal. The voltage of a signal at a reset voltage end is a positive voltage, and the voltage of a signal at a first initial voltage end is a negative voltage.

Abstract: The present invention provides a crane boom with multi main chord consisting of an underpart boom sections, an insert jib section and a boom head connected in turn. Said underpart boom sections and insert jib section are multi-main-chord boom sections, there is a main-chord on each of the angle part of the cross-section of the multi-main-chord boom section. Said main-chords are connected one another by several belly bars. Add at least one main-chord on the angle part of the cross section along the width or the height of said multi-main-chord boom, and the added main-chord parallels to the original main-chord. The crane boom with multi main chord of the present invention, without changing the size of the boom sections during transporting, the cross-sectional area of the main-chord is increased and the integral stiffness of the boom is strengthened by increasing main-chord number of boom, thus fold increasing the structural carrying capacity of the boom which is suitable for large crane.