Abstract: A range finder includes a laser transmitter, a laser receiver, a large-aperture objective lens unit, an image sensing device, a display device and a microphone. The laser transmitter is configured to emit a laser beam to a measured object. The laser receiver is configured to receive a reflected laser beam reflected by the measured object. The objective lens unit is configured to allow visible light reflected by the measured object to pass therethrough, includes an objective lens and a focusing lens and has a length defined by the objective lens and the focusing lens. The image sensing device is configured to receive the visible light passing through the objective lens and generate an image signal. The length is constant when the objective lens unit is moved with respect to the image sensing device for focusing operation.

Abstract: A range finder includes a laser transmitter, a laser receiver, a large-aperture objective lens unit, an image sensing device, a display device and a microphone. The laser transmitter is configured to emit a laser beam to a measured object. The laser receiver is configured to receive a reflected laser beam reflected by the measured object. The objective lens unit is configured to allow visible light reflected by the measured object to pass therethrough, includes an objective lens and a focusing lens and has a length defined by the objective lens and the focusing lens. The image sensing device is configured to receive the visible light passing through the objective lens and generate an image signal. The length is constant when the objective lens unit is moved with respect to the image sensing device for focusing operation.

Abstract: A lens assembly includes a stop, a first lens, a second lens and a third lens, all of which are arranged in sequence from an object side to an image side along an optical axis. The first lens is a plano-convex lens with positive refractive power and includes a convex surface facing the object side. The second lens is with negative refractive power. The third lens is with positive refractive power and includes a convex surface facing the object side. The third lens satisfies 0<f3/f<1, wherein f3 is an effective focal length of the third lens and f is an effective focal length of the lens assembly.

Abstract: A range finder includes a laser transmitter, a laser receiver, an objective lens, an image sensing device, a display device and a microphone. The laser transmitter is configured to emit a laser beam to a measured object. The laser receiver is configured to receive a reflected laser beam reflected by the measured object. The objective lens is configured to allow visible light reflected by the measured object to pass therethrough. The image sensing device is configured to receive the visible light passing through the objective lens and generate an image signal. The display device is configured to receive the image signal and display an image of the measured object. The microphone is configured to record sound.

Abstract: A barcode reading method and a barcode reading device are provided. An image sensor is utilized to capture an image of a barcode via an optical lens, and then a triangulation method and an ideal lens imagining method are collocated to calculate the digital image so as to produce an optimum image distance. A distance between the image sensor and the optical lens is then adjusted in accordance with the optimum image distance, so that the barcode can be immediately and clearly imaged on the image sensor.

Abstract: A barcode reading method and a barcode reading device are provided. An image sensor is utilized to capture an image of a barcode via an optical lens, and then a triangulation method and an ideal lens imagining method are collocated to calculate the digital image so as to produce an optimum image distance. A distance between the image sensor and the optical lens is then adjusted in accordance with the optimum image distance, so that the barcode can be immediately and clearly imaged on the image sensor.

Abstract: A laser distance measuring system includes an object lens, a beam splitter, a transmitter, a receiver, and a shutter mechanism. The beam splitter is disposed at one side of the object lens. The transmitter emits a laser beam that is split by the beam splitter into a measurement beam and a reference beam. The measurement beam passes through the object lens, and is reflected by an object to result in a reflected measurement beam passing through the object lens. The receiver is disposed to receive the reflected measurement beam and the reference beam. The shutter mechanism includes a beam masker operable to move to either block path of the reflected measurement beam to the receiver or path of the reference beam to the receiver.

Abstract: An optical system (1) of telescope includes an objective lens (10) for collecting incident light and transmitting the incident light along a light path, and an imaging lens group (20) disposed on the light path that makes the optical system focus on an image plane (40). The imaging lens group includes two positive lenses and two negative lenses. Each lens of the imaging lens group has a refractive index less than 1.80.

Abstract: A laser distance measuring system includes an object lens, a beam splitter, a transmitter, a receiver, and a shutter mechanism. The beam splitter is disposed at one side of the object lens. The transmitter emits a laser beam that is split by the beam splitter into a measurement beam and a reference beam. The measurement beam passes through the object lens, and is reflected by an object to result in a reflected measurement beam passing through the object lens. The receiver is disposed to receive the reflected measurement beam and the reference beam. The shutter mechanism includes a beam masker operable to move to either block path of the reflected measurement beam to the receiver or path of the reference beam to the receiver.

Abstract: A laser distance-measuring device includes a laser-transmitting portion, a laser-receiving portion, a coupling portion, an inclination-measuring portion, a signal-processing portion, and a display. The laser-transmitting portion emits a laser beam, and the laser-receiving portion receives the laser beam. The coupling portion interconnects the laser-receiving portion and the signal-processing portion. The inclination-measuring portion detects an inclination angle of the laser beam. The signal-processing portion processes the signals received from the laser-receiving portion and the inclination-measuring portion and sends the result to the display. The display receives and displays the result of processing by the signal-processing portion.

Abstract: An optical axis adjusting mechanism disposed on a laser ruler for adjusting an optical axis of the laser ruler is provided. The laser ruler includes a main bracket. The optical axis adjusting mechanism includes a main body rotatably assembled to the main bracket of the laser ruler with a shaft, and one or more adjusting elements for selectively rotating the main body about the shaft to adjust an optical axis of the laser ruler.

Abstract: A laser distance-measuring device includes a laser-transmitting portion, a laser-receiving portion, a coupling portion, an inclination-measuring portion, a signal-processing portion, and a display. The laser-transmitting portion emits a laser beam, and the laser-receiving portion receives the laser beam. The coupling portion interconnects the laser-receiving portion and the signal-processing portion. The inclination-measuring portion detects an inclination angle of the laser beam. The signal-processing portion processes the signals received from the laser-receiving portion and the inclination-measuring portion and sends the result to the display. The display receives and displays the result of processing by the signal-processing portion.

Abstract: An optical system (1) of telescope includes an objective lens (10) for collecting incident light and transmitting the incident light along a light path, and an imaging lens group (20) disposed on the light path that makes the optical system focus on an image plane (40). The imaging lens group includes two positive lenses and two negative lenses. Each lens of the imaging lens group has a refractive index less than 1.80.