Abstract: A surveillance device includes a front cover, at least two guide rods, a lens module, a mounting plate, a first balance spring, a circuit board, and a number of second balance springs. The guide rods are mounted in the front cover. The lens module is received the first through hole. The mounting plate is slidably mounted to the guide rods. The mounting plate defines a through hole. The first balance spring is positioned between the front cover and the mounting plate. The circuit board is mounted to the mounting plate and opposite to the first balance spring. The image sensor is mounted on the circuit board and faces the through and the lens module. The second balance springs are positioned between the mounting plate and the circuit board. The first balance spring and the second balance springs keep the image sensor being aligned with the lens module.

Abstract: An adjustable lens structure includes a lens housing, a lens module, a rotatable lens seat, and a shifting apparatus. The lens housing has a front housing and a top housing located behind the front housing. The front housing is a hollow cylinder and the rotatable lens seat is placed inside the front housing. The lens module is placed on the rotatable lens seat. The shifting apparatus is engaged with the top housing. The shifting apparatus has a gear assembly engaged with the rotatable lens seat to provide adjustable shooting angle for the lens module.

Abstract: A foldable screen protector for use on a computer monitor of various kinds has a fixing frame, a foldable top cover, and foldable left and right plates, thereof the fixing frame is adapted and secured to the screen of different types of computer monitors even to that of a notebook computer to provide the screen with protections against reflection of sunlight and oversight of others from outside; and by use of protruded tracks intersecting across the surface of the foldable top cover to reduce the amount of friction and a torsion spring, the foldable top cover and the foldable left and right plates can be folded and unfolded easily. When not in use, the foldable top cover can be folded up and lodged to the fixing frame as a protector to the screen.