Abstract: A knob structure includes a base, a rotational element, a clicking plate and a clicking sheet. The rotational element is rotatably disposed on the base and includes inner peripheral surfaces. The clicking plate is joined to the inner peripheral surfaces of the rotational element and includes a plurality of first engaging members. The clicking sheet is joined to the base and includes at least one second engaging member. The clicking plate is held between the base and the clicking sheet to force the clicking sheet against the clicking plate. The rotational element is configured to rotate the clicking plate with respect to the clicking sheet so that the second engaging member continuously engages with the first engaging members.

Abstract: A rotating cylinder device includes a cylindrical belt having an axis line, several plate-shaped parts, several link mechanisms, and a cylindrical casing. The plate-shaped parts are disposed outside the belt and arranged symmetrically across the axis line. The link mechanisms are pivotally connected to the respective plate-shaped parts and each have a moving protrusion. The moving protrusions are adapted to move along a first direction parallel to the axis line. The cylindrical casing is adapted to rotate about the axis line and is coupled to the moving protrusions. When the cylindrical casing rotates about the axis line, the moving protrusions are driven to move along the first direction, and the plate-shaped parts are driven by the link mechanisms to move along a second direction perpendicular to the axis line, to contract the belt.

Abstract: A lens assembly includes a fifth lens, a first lens, a second lens, a third lens and a fourth lens, all of which are arranged in sequence from an object side to an image side along an optical axis. The second lens is a biconcave lens. The third lens is a biconvex lens and made of glass material. The fourth lens includes a concave surface facing the object side.

Abstract: A sight capable of measuring distance comprises a telescope without any turrets, a laser transmitting module, a mount for adjusting elevation and windage and a power supply. The telescope comprises a barrel, an unadjustable reticle fixed in the barrel and a laser receiving module fixed in the barrel. The laser transmitting module is steadfastly fixed on the outer barrel of the telescope and emitting a laser beam toward the target. The mount for adjusting elevation and windage is fixed on a lower side of the outer barrel of telescope, and comprises a mounting part, an elevation adjusting part and a windage adjusting part. The power supply electrically connects to the laser transmitting module and the laser receiving module.

Abstract: A binoculars rangefinder includes a central shaft, two eyepieces, two objective lenses, two prism modules, an optical transmitter, and an optical receiver. The eyepieces are disposed on two sides of the central shaft, allowing a first light beam reflected by an object to pass therethrough. The objective lenses are disposed on the two sides of the central shaft. The prism modules are disposed between the eyepieces and objective lenses. The optical transmitter is configured to emit a second light beam to the object. The optical receiver is configured to receive the second beam which is reflected by the object.

Abstract: A trajectory prediction system for predicting a point of impact of an object shot from a ballistic device is provided. The trajectory prediction system includes an objective lens, an eyepiece lens optically coupled with the objective lens, an image sensor, a processor, and a display electrically connected to the processor and the image sensor. The image sensor, the processor, and the display are disposed between the objective lens and the eyepiece lens. When an external light reaches the image sensor through the objective lens, the image sensor transmits a first signal to the display, and the display shows an image according to the first signal. The processor calculates the trajectory of the object and transmits a second signal to the display, and the display simultaneously shows the image and at least one predictive point of impact according to the first and second signals.

Abstract: A headphone is provided. The headphone includes a housing and an speaker. The housing includes a first layer structure, a first receiving space, a first output path, a first trench and a sound output side. The speaker is located in the first receiving space, wherein the speaker includes a first speaker orientation, and the first speaker orientation corresponds to the first output path. The first output path includes the first trench, which is located at the first layer structure, extends around the speaker, and is connected to the sound output side.

Abstract: A headphone is provided. The headphone includes a housing, a first speaker and a second speaker. The housing includes a sound output side, a first layer structure, a first output path, a first trench, a first recess, and a second recess. The first speaker is disposed in the first recess, wherein the first speaker includes a first speaker orientation, and the first speaker orientation corresponds to the first output path. The second speaker is disposed in the second recess. The first output path includes the first trench, which is located at the first layer structure, that extends around the first speaker, and is connected to the sound output side.

Abstract: A sight includes a cylinder, a first lens, a first lens seat, and at least one first elastic member. The first lens is disposed in the cylinder. The first lens seat carrying the first lens is disposed in the cylinder. The first elastic member is disposed between an outer surface of the first lens seat and an inner periphery of the cylinder, wherein the first lens seat is tightly fitted with the cylinder and light enters the cylinder through the first lens.

Abstract: A lens assembly includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens. The first lens is with positive refractive power. The second lens is with negative refractive power. The third lens is with positive refractive power. The fourth lens is a meniscus lens and includes a concave surface facing the object side and a convex surface facing the image side. The fifth lens includes a concave surface facing the image side. The first lens and the third lens are made of the same material and an Abbe number of the first lens is the same as an Abbe number of the third lens. An Abbe number of the first lens, an Abbe number of the third lens and an Abbe number of the fifth lens are greater than an Abbe number of the second lens.

Abstract: A near infrared lens assembly includes a first lens, a second lens, a third lens and a fourth lens, all of which are arranged in sequence from an object side to an image side along an optical axis. The first lens is with positive refractive power and includes a convex surface facing the object side. The second lens is a meniscus lens and includes a convex surface facing the object side and a concave surface facing the image side. The third lens is a meniscus lens and includes a concave surface facing the object side and a convex surface facing the image side. The fourth lens is with negative refractive power and includes a concave surface facing the object side.

Abstract: A pico projector includes a housing, a lens, a light engine, a control module and a central processing module. The housing includes a main body and a cover. The lens is disposed in the housing. The light engine is disposed in the housing and configured to produce light including image signals and project the light through the lens. The control module is configured to provide a control signal. The central processing module is disposed in the housing and configured to rotate or move the cover with respect to the main body according to the control signal so as to create an opening for enhancing heat dissipation of the interior of the housing.

Abstract: An active protection system for protecting an object includes a first lens, a second lens, a processing unit and an alarm unit. The first lens is configured to receive first light and generate a first image. The second lens is configured to receive second light and generate a second image. The processing unit is configured to obtain a characteristic value of the object from the second image, determine whether the characteristic value reaches a pre-set value, and judge whether the object is regulated in a predetermined period after the characteristic value reaches the pre-set value. The alarm unit is configured to raise an alarm under control of the processing unit if the object is not regulated in the predetermined period after the characteristic value reaches the pre-set value.

Abstract: A zoom lens, in sequence from an object side to an image side along an optical axis, comprises a first lens group; a second lens group; a stop; and a rear lens group and comprising a third lens group, a fourth lens group, and a fifth lens group; the fourth lens group further comprises an image correction lens which is able to shifted in a direction transverse to the optical axis of the zoom lens to stabilize the picked-up image when the zoom lens vibrates; furthermore, the zoom lens satisfies the following condition: (1??p)×?r>2, where ?p is a lateral magnification of the image correction lens when the zoom lens is at the telephoto end, and where ?r is a lateral magnification of the lenses in the rear lens group except for the lenses in front of the image correction lens when the zoom lens is at the telephoto end.

Abstract: A sight includes a main body including a focus lens system and an erecting lens system; a first adjusting member disposed in the main body and configured to move the focus lens system along the optical axis; a second adjusting member disposed in the main body and configured to move the erecting lens system in a first direction which is perpendicular to the optical axis; a focus adjusting module disposed in the main body and configured to drive the first adjusting member so as to move the focus lens system along the optical axis; and a first adjusting module detachably joined to the focus adjusting module and configured to drive the second adjusting member so as to move the erecting lens system in the first direction.

Abstract: A zoom lens has a four-group zoom configuration, in order from the object side to the image side, consisting of negative, positive, positive, and positive refractive power. The zoom lens carries out zooming from the wide-angle end to the telephoto end mainly by changing the distance between the third lens group and the fourth lens group. Also, the distance between the second lens group and the third lens group may be decreased in the zooming. Focusing is carried out mainly by moving the second lens group along the optical axis. Such a zoom lens is thin and small in size, and has a great imaging performance.

Abstract: A sight includes an adjusting module, a collector ring, a first adjusting element, and an elastic element. The collector ring includes a connecting end connected to the adjusting module, a free end opposite to the connecting end, a periphery connecting the connecting end and the free end, and a notch formed on the periphery and connected to the free end. The first adjusting element includes a first end which abuts the periphery. The elastic element extends in a direction from the free end to the connecting end and abuts the periphery. The elastic element contacts the periphery in a position between the notch and the connecting end. The first end is configured to resist an elastic force exerted by the elastic element and move the collector ring.