Abstract: A freeform imaging lens defined in a (x, y, z) coordinate is provided. The freeform imaging lens comprises a first surface and a second surface opposite to the first surface. The first surface comprises a first freeform surface and a second freeform surface symmetrical about x-z plane. The first freeform surface and the second freeform surface are 5th order xy-polynomial curve surfaces. The second surface is a 10th order aspheric surface. The present disclosure also relates to a freeform imaging system using the above freeform imaging lens.

Abstract: A method for providing an interactive user interface on a mobile terminal having a touch screen, including: displaying a content layer and a background layer corresponding to the content layer; detecting a contact event occurring on the screen of the mobile terminal and obtaining an operation command corresponding to the contact event; and executing an operation according to the obtained operation command; wherein the background layer is located below the content layer and is configured to display a scene as a background; and the content layer is configured to arrange at least a component for user interaction, a preset point of an icon corresponding to the component being set to correspond to a preset position of the content layer, and the preset position of the content layer being set to correspond to a preset position of the scene displayed by the background layer.

Abstract: A design method of freeform imaging system is provided. An initial freeform imaging system is provided, the initial freeform image system comprising a first initial surface and a second initial surface spaced from each other. A second surface is constructed by calculating a plurality of second data points of the second surface through a plurality of feature rays based on the given object-image relationship. A first surface is constructed by calculating a plurality of first data points of the first surface based on the given object-image relationship and Fermat's principle, wherein the second surface is fixed. The first surface and the second surface substitute for the first initial surface and second initial surface respectively, and repeating steps list above, wherein the plurality of feature rays are intersecting the image plane at the plurality of ideal image points.

Abstract: A light emitting diode includes a first semiconductor layer, an active layer, a second semiconductor layer, a protective layer, and a cermet layer. The active layer is on the first semiconductor layer. The second semiconductor layer is on the active layer. the protective layer is located on the semiconductor layer. The cermet layer is located on the protective layer. A first electrode covers entire surface of the first semiconductor layer away from the active layer. A second electrode is electrically connected to the second semiconductor layer.

Abstract: A method for designing three-dimensional freeform surface is provided. An initial surface and a first three-dimensional rectangular coordinates system are established. A number of feature rays are selected. A number of intersections of the feature rays with a first freeform surface are calculated, wherein the intersections are a number of feature data points. The first freeform surface is obtained by surface fitting the feature data points. An equation of the first freeform surface includes a conic term and a freeform surface term. The first freeform surface is taken as the initial surface for an iteration process.

Abstract: A method for designing off-axial optical system with freeform surfaces is provided. An initial system is established. A freeform surface of the off-axial optical system that needs to be solved is defined as a freeform surface. A number of feature rays are selected. A number of intersections of the feature rays with the freeform surface are calculated point by point based on a given object-image relationship and a vector form of Snell's law. A number of first feature data points are obtained from the intersections and surface fitted to obtain the freeform surface. All the freeform surfaces of the off-axial optical system that need to be solved are obtained by the method above to form a before-iteration off-axial optical system. The before-iteration off-axial optical system is used as the initial system for multiple iterations to obtain an after-iteration off-axial optical system.

Abstract: A method for designing freeform surface off-axial three-mirror imaging system with a real exit pupil is related. An initial system is established. A surface located before the real exit pupil is defined as surface M. A number of feature rays are selected. A number of ideal intersections of the feature rays with surface M are calculated. A number of intersections of the feature rays with each surface before surface M are calculated, and each surface before surface M is obtained by surface fitting. A number of intersections of the feature rays with surface M are calculated, and surface M is obtained by surface fitting. Surface M substitute for an initial surface, and repeating steps above, until the intersections of the feature rays with surface M are close to the ideal intersections, and the intersections of the feature rays with an image surface are close to the ideal image points.

Abstract: The present application is directed to apparatuses and methods for preventing information disclosure. According to example embodiments of the present application, after a mobile terminal of a user is lost, a first short message may be sent to the mobile terminal through a short message network. When the mobile terminal determines that the received short message is the first short message, user information stored in the mobile terminal may be erased by the mobile terminal.

Abstract: An off-axial three-mirror optical system with freeform surfaces includes an aperture, a primary mirror, a secondary mirror, a tertiary mirror, and a detector. The aperture is located on an incident light path. The primary mirror is located on an aperture transmitted light path. The secondary mirror is located on a primary mirror reflected light path. The tertiary mirror is located on a secondary mirror reflected light path. The detector located on a tertiary mirror reflected light path. A primary mirror surface and a tertiary mirror surface have a same freeform surface equation, and the freeform surface equation is a sixth order x?y? polynomial. A secondary mirror surface is a tenth order aspherical surface.

Abstract: An off-axis three-mirror optical system with freeform surfaces includes a primary mirror, a secondary mirror, a tertiary mirror, and an image sensor. The primary mirror receives light rays first and the secondary mirror is located on a path of light reflected from the primary mirror. The tertiary mirror receives light reflected from the secondary mirror. The image sensor is located on a path of light reflected from the tertiary mirror. Each reflecting surface of the primary and tertiary mirrors is a sixth order xy polynomial freeform surface. The secondary mirror reflecting surface is a spherical surface. A field of view of the off-axis three-mirror optical system with freeform surfaces in Y-axis direction is greater or equal to 65°. A field of view of the off-axis three-mirror optical system with freeform surfaces in X-axis direction is greater or equal to 0.8°.

Abstract: A method for designing an off-axis three-mirror imaging system with freeform surfaces is provided. A primary mirror initial structure, a secondary mirror initial structure, and a tertiary mirror initial structure are established. A number of first feature rays are selected, while the primary mirror initial structure and the secondary mirror initial structure unchanged. The first feature rays are forward ray tracked from an object space to an image detector. A number of first feature data points are calculated to obtain a tertiary mirror. A number of fields and a number of second feature rays are selected, while the secondary mirror initial structure and the tertiary mirror unchanged. The second feature rays are reverse ray tracked from the image detector to the object space. A number of second feature data points are calculated to obtain the primary mirror.

Abstract: A semiconductor structure includes a first semiconductor layer, an active layer, a second semiconductor layer, and a cermet layer stacked together. The active layer is on a surface of the first semiconductor layer. The second semiconductor layer is on a surface of the active layer away from the first semiconductor layer. The cermet layer is on a surface of the second semiconductor layer away from the first semiconductor layer.

Abstract: The present application is directed to apparatuses and methods for preventing information disclosure. According to example embodiments of the present application, after a mobile terminal of a user is lost, a first short message may be sent to the mobile terminal through a short message network. When the mobile terminal determines that the received short message is the first short message, user information stored in the mobile terminal may be erased by the mobile terminal.

Abstract: A laser includes a total reflective mirror, an output mirror, a discharge lamp, and an active laser medium. The total reflective mirror, the output mirror, and the discharge lamp define a resonant cavity. The active laser medium is filled in the resonant cavity. The total reflective mirror includes a body, a metal film, and at least one microstructure. The at least one microstructure has a height and a lateral size, and both the height and the lateral size are in a range from about 0.5? to about 2?, while ? is a working wavelength of the laser.

Abstract: A LED optical communication receiving lens includes a first surface and a second surface opposite to the first surface. The first surface includes a first spherical surface and a second spherical surface connected to the first spherical surface. The second surface includes a third spherical surface and a planar surface connected to the third spherical surface. A position of the LED optical communication receiving lens is defined as a three-dimensional Cartesian coordinate system (x, y, z). Sphere centers and symmetric central points of the first spherical surface, the second spherical surface, and the third spherical surface are located on the x axis. The first spherical surface and the planar surface are transmitted surfaces. The second spherical surface and the third spherical surface are reflective surfaces. The present application also relates to a LED optical communication system including the LED optical communication receiving lens.

Abstract: A method for controlling screen rotation for use in a mobile terminal is provided. The method includes: when the mobile terminal enters a full-screen mode, locking a screen orientation of the mobile terminal, and acquiring an initial posture of the mobile terminal; monitoring a real-time posture of the mobile terminal in real time; and determining a screen rotation direction by comparing the real-time posture with the initial posture.

Abstract: An off-axial three-mirror optical system with freeform surfaces includes a primary mirror, a secondary mirror, a tertiary mirror, and a detector. The primary mirror is located on an incident light path. The secondary mirror is located on a primary mirror reflecting light path. The tertiary mirror is located on a secondary mirror reflecting light path. The detector is located on a tertiary mirror reflecting light path. Each of the primary mirror, the secondary mirror, and the tertiary mirror is an xy polynomial freeform surface up to the fifth order.

Abstract: An off-axial three-mirror optical system with freeform surfaces includes a primary mirror, a secondary mirror, a tertiary mirror, and an image sensor. The primary mirror is located on an incident light path. The secondary mirror is located on a primary mirror reflecting light path. The tertiary mirror is located on a secondary mirror reflecting light path. The image sensor is located on a tertiary mirror reflecting light path. The primary mirror, the secondary mirror, and the tertiary mirror are all xy polynomial surfaces up to the sixth order. The off-axial three-mirror optical system with freeform surfaces can achieve push-broom image with small F-number and large field angles.

Abstract: A freeform surface reflective scanning system includes a light source, an aperture, a first freeform surface mirror, and a second freeform surface mirror. The light source is configured to provide a laser. The first freeform surface mirror is located on an aperture side that is away from the light source. The first freeform surface mirror is configured to reflect the laser to form a first reflected light. The second freeform surface mirror is located on a first reflected light path. The second freeform surface mirror is configured to reflect the first reflected light to form a second reflected light. Both the first freeform surface mirror and the second freeform surface mirror are a fourth XY polynomial surface.

Abstract: An off-axial three-mirror system includes a primary mirror, a secondary mirror, a tertiary mirror, and an image sensor. The secondary mirror is located on a reflective optical path of the primary mirror. The tertiary mirror is located on a reflective optical path of the secondary mirror. The image sensor is located on a reflecting optical path of the tertiary mirror. The primary mirror and the tertiary mirror are formed as one piece. The surface type of both the primary mirror and the tertiary mirror is a freeform surface.