Abstract: An optical photographing lens assembly includes seven lens elements which are, in order from an object side to an image side: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element. Each of the seven lens elements of the optical photographing lens assembly has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The object-side surface of the first lens element is concave in a paraxial region thereof. The object-side surface of the first lens element is aspheric and has at least one critical point in an off-axis region thereof.

Abstract: A flyback converter includes: a transformer including a primary winding and a secondary winding; a first switch coupled to the primary winding; a first control module configured to control the first switch; a second switch coupled to the secondary winding; and a second control module configured to control the second switch, such that the second switch operates in an ON state during a first time period and during a second time period which follows the first time period, and such that a current flowing through the secondary winding has a direction during the second time period opposite to that during the first time period.

Abstract: A screen reeling device includes a frame, an axle, a driving member, an elongated roller, and a biasing member. The frame includes left and right bracket members. The axle has a proximate end mounted to the right bracket member, and a distal end. The driving member is retained slidably and rotatably on the frame and has a right transverse end wall proximate to the right bracket member, and a left end portion. The elongated roller is adapted to be wound with the screen thereon, and includes a left end portion journalled on the left bracket member and an axially hollowed right end portion which is sleeved securely on the left end portion of the driving member to be rotatable therewith. The biasing member biases the right transverse end wall axially toward the right bracket member.

Abstract: A tensioning device is to be used with a control cord of a blind assembly and includes a hollow casing which confines a vertically extending receiving space and which has an open top end portion and a bottom end provided with a pivot portion. A pivot unit mounts rotatably the pivot portion of the casing on a wall body. A cord engaging unit has a pulley formed with a cord engaging groove for passing over of the control cord, and a base slidably provided in the receiving space and having a front side formed with a pulley receiving recess. The pulley is mounted rotatably to the base in the pulley receiving recess. The base further has a top wall formed with a pair of notches which permit extension of parallel sections of the control cord that passes over the pulley. A cover member is mounted on the open top end portion of the casing, and is formed with a pair of slits that are aligned with the notches in the top wall of the base and that permit extension of the parallel sections of the control cord therethrough.