30results about How to "Large distortion" patented technology

The invention discloses a near infrared optical lens. The near infrared optical lens comprises right eyeglasses successively arranged from an object side to an image side, wherein the first eyeglass is crescent-shaped, has negative focal power and has a convex surface oriented towards the object side; the second eyeglass is crescent-shaped, has negative focal power and has a convex surface oriented towards the object side; the third eyeglass is biconvex-shaped and has positive focal power; the fourth eyeglass is crescent-shaped, has positive focal power and has a convex surface oriented towards the image side; a doublet is formed by combining the fifth eyeglass with the sixth eyeglass; a seventh eyeglass is biconvex-shaped and has positive focal power; and the eighth eyeglass is crescent-shaped, has positive focal power and has a convex surface oriented towards the object side. The near infrared optical lens, through adoption of different eyeglass combinations and utilization of focal power distribution, has good performance of wide aperture, large visual angle and small distortion, and can effectively realize a heat difference elimination effect by use of a full glass structure.

The invention provides a double-film refraction and reflection type co-detector imaging system, and belongs to the technical field of optics. The system comprises a primary mirror, a secondary mirror, a relay mirror group and a focal plane detector, wherein the primary mirror, the secondary mirror, the relay mirror group and the focal plane detector are placed sharing the same optical axis; the primary mirror and the secondary mirror are of a Cassegrain structure; the primary mirror is provided with a central hole, the secondary mirror is placed in front of the primary mirror, and the relay mirror group and the focal plane detector are placed at the back of the secondary mirror; the secondary mirror is a Mangin mirror, the front surface of the secondary mirror reflects medium wave infrareds and transmits long wave infrareds, and the back surface of the secondary mirror reflects long wave infrareds; arrangement of the two reflecting surfaces of the secondary mirror enables the medium wave infrareds and the long wave infrareds to be the same in optical distance so as to enable the medium wave infrareds and the long wave infrareds to be imaged on the same focal plane under the condition without focusing. The system can achieve two-waveband operation and imaging in a long focal distance and with a large relative aperture, and is compact in structure and little in distortion, a transfer function reaches or is close to a diffraction limit, and cold aperture matching reaches 100%.

The invention discloses a double-sampling-rate distribution network line fault point accurate positioning method based on singular value decomposition and a device thereof. The method comprises the steps of performing phase correlation calculation on a phase current waveform which is acquired by low-sampling-rate measuring equipment, starting a wave recording function of high-sampling-rate measuring equipment when occurrence of a fault is determined, then processing the phase current waveform which is acquired by the high-sampling-rate measuring equipment, and performing accurate positioning on the fault point according to a D-type traveling wave method. According to the method and the device, through performing correlation coefficient calculation on the waveform data, a problem of low reliability in traditional amplitude triggered wave recording is settled. Furthermore correlation calculation is only performed on the low-sampling-rate data, thereby effectively reducing calculation amount and increasing fault wave recording triggering speed. Furthermore the utilized high-sampling-rate measuring equipment has a small sampling time window and does not depend on a high storage capacity, thereby effectively reducing cost of distribution network testing equipment.

The invention discloses a microporous metal cooling mirror and a production method thereof. The cooling mirror comprises a mirror body and a mirror frame, wherein the mirror body comprises a mirror plate and a foam metal microporous layer which are integrally brazed; and the mirror frame comprises at least two liquid access passageways and is positioned behind the foam metal microporous layer to be tightly connected with the mirror body. The mirror plate and foam metal are directly brazed by adopting the brazing technology, so that cooling liquid can flow circularly in the foam metal; and therefore, the purposes of cooling the mirror plate and reducing the temperature rise and the deformation of the mirror plate are achieved. According to the invention, uniform and controllable microporous cooling layers are obtained on the mirror plate, so that large deformation of the mirror plate is inhibited and the problem that the foam metal and the mirror plate are difficult to weld during brazing is solved; and under the action of the capillary force, melted brazing filler metal is fed into the bottom layer of the foam metal suitably, so that the contact thermal contact resistance between the bottom layer of the foam metal and the base of the mirror plate is reduced. The brazing technology can be directly used for producing microporous metal cooling mirrors, so that the method is simple and the operation is easy.

An electric power assist device can be compactly disposed with ease in an electric power steering system for a vehicle. The electric power steering system for a vehicle comprises: a steering wheel; a steering column incorporating therein a steering shaft connected to the steering wheel and extending downward to the front; and an electric power assist device for assisting a steering torque of the steering wheel. Here, an input shaft and an output shaft of the electric power assist device are connected to the lower end of the steering shaft and the input shaft of the steering gear device, respectively, via universal joints.

The invention discloses an optical system of a depth camera. The optical system comprises six lenses that are arranged successively along the optical axis from object space to image space. The first lens has a crescent shape with a negative focal power and a convex surface of the first lens faces the object space; the second lens has a crescent shape with a negative focal power and a convex surface of the second lens faces the object space; the third lens has a biconvex shape with a positive focal power; the fourth lens has a biconcave shape with a negative focal power; the fifth lens has a biconvex shape with a positive focal power; and the sixth lens has a biconvex shape with a positive focal power. According to the optical system of the depth camera, with different lens combination units and focal-power distribution, excellent performances of large aperture, large view angle, and low distortion are realized; and on the basis of the glass-plastic mixing structure, athermalization and low manufacturing cost can be effectively considered.

A phosphomolybdate has the molecular formula of K4M5P4Mo4HO27, and has the powder frequency-doubling intensity the same as that of KDP; when M is K, the phosphomolybdate is potassium hydrogen phosphomolybdate, the crystal belongs to a tetragonal system, the space group is I-4c2, unit cell parameters comprise a=9.670 angstroms, c=29.335 angstroms, alpha=beta=gamma=90 DEG and Z=4, and the unit cell volume is V=2743.1 cubic angstroms; when M is Rb, the phosphomolybdate is rubidium potassium hydrogen phosphomolybdate, the crystal also belongs to a tetragonal system, the space group is I-4c2, unit cell parameters comprise a=9.768 angstroms, c=29.635 angstroms, alpha=beta=gamma=90 DEG and Z=4, and the unit cell volume is V=2827.7 cubic angstroms; the two crystals are both grown by a fluxing agent spontaneous nucleation method or a fluxing agent top seed crystal method; the two crystals both have the nonlinear optical effect, and are incongruent melting compounds; and the two crystals as nonlinear optical crystals from infrared band to ultraviolet band can be used for preparation of a laser output frequency conversion laser device or used for preparation of a generator for generating a second, third, fourth or fifth harmonic generation harmonic to a laser beam with the wavelength of 1064 nm.

The invention discloses an optical lens. The optical lens sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from an object side to an imageside along an optical axis. The first lens can have negative focal power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the second lens can have positive focal power, and the object side surface of the second lens is a convex surface; the fifth lens can have positive focal power, and the object side surface and the image side surface of the fifth lens are convex surfaces; the sixth lens can have negative focal power, and the image side surface of the sixth lens is a concave surface; and the third lens and thefourth lens can be mutually glued to form a glued lens. According to the optical lens provided by the invention, at least one of the beneficial effects of high resolution, miniaturization, small-caliber front end, long coking, large field angle, small principal ray angle, long back focal length and the like can be realized.

The invention provides an on-orbit calibration device and on-orbit calibration method for pointing precision of a remote sensor. The device includes a calibration processing module, a filter component, and an imaging component, wherein the filter component is mounted on the imaging component to filter out the light sources outside the range of a calibration source spectrum, and only enable a calibration light source passing through the optical path system of the remote sensor to be calibrated to pass through; the imaging area of the imaging component includes a calibration area and an imagingarea, the calibration area is located at the edge of the imaging area, the surface of the calibration area is installed with the filter component, and the calibration area receives an optical signal of the calibration light source passing through the filter component, converts the optical signal into an electrical signal, and outputs the electrical signal to the calibration processing module; theimaging area receives the optical signal of an observation target, converts the optical signal of the observation target into an electrical signal, and outputs the electrical signal to an external digital transmission subsystem; and the calibration processing module determines the position coordinate of the calibration light source on the imaging component according to the electrical signal of thecalibration light source, and completes the on-orbit calibration of the pointing accuracy of the remote sensor. The on-orbit calibration device and on-orbit calibration method for pointing precisionof the remote sensor have the advantages of compact structure, convenient installation and high reliability.

The invention discloses an optical system for film projection and projection equipment. The optical system comprises a film, an illumination system and a projection objective lens, the projection objective lens comprises a first lens, a second lens, a third lens, an aperture diaphragm, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged along the same optical axis from a film side to an imaging side, the first lens, the second lens, the fourth lens and the fifth lens are positive lenses, and the third lens and the sixth lens are negative lenses; the F number of the projection objective lens is in a range of 3-6; the illumination system comprises a light source and a lens group, light emitted by the light source passes through the lens group and then enters a film in the form of collimated light or convergent light forming an angle of less than or equal to 10 degrees with a horizontal line, and the light entering a first lens after passing through the film is parallel to an optical axis or converges towards the optical axis at an angle of less than or equal to 10 degrees with the horizontal line; and finally imaging is performed on an imaging target surface through the projection objective lens. The optical system has the advantages of high imaging quality, low distortion, large projection area and the like.

The invention discloses a complex bending and twisting thin plate decoration component based on an annular space structure and an assembling method thereof, and relates to the field of steel structures, the complex bending and twisting thin plate decoration component comprises a mounting base, the bending and twisting component is of a sectional structure, by arranging a plurality of bending and twisting assemblies, the bending and twisting component with the large size can be decomposed into components with the small size, and the device is convenient to transport and assemble; the multiple bending and twisting assemblies are connected through the first flanges and the second flanges, the device is convenient to disassemble, most of the structure can be completely reserved to the maximum extent after disassembly, materials can be reused, the structure is firmer and the twisting amplitude is larger after the device is assembled by arranging the partition plate assembly, and the practicability is high. The working performance of the device is greatly improved, the interior of the reinforcing partition plate is of a hollow structure, a plurality of reinforcing plates are fixedly connected to the interior of a cavity of the reinforcing partition plate, the weight of the reinforcing partition plate is greatly reduced through the cavity structure, and the structural strength is improved while the self weight of the reinforcing plates is reduced through the reinforcing plates.

The invention discloses a positioning method and a device for distribution network line fault points based on a double sampling rate. Phase correlation calculation is carried out on phase current waveforms acquired by a low sampling rate measuring apparatus. A recording function of a high sampling rate measuring apparatus is started when a fault occurs. Phase current waveforms acquired by the highsampling rate measuring apparatus are processed by a short-time Fourier transform. Accurate positioning is carried out on the fault points according to a D-type traveling wave method. According to the positioning method and the device for the distribution network line fault points based on the double sampling rate, the correlation coefficient calculation is carried out on waveform data, so as tosolve the unreliable problem of the traditional amplitude triggering recording wave; correlation calculation is only carried out on low sampling rate data, so as to reduce the calculation amount and improve the fault recording triggering speed; and meanwhile, a sampling time window of the high sampling rate measuring apparatus is small, so as to not rely on the large storage capacity and reduce the cost of distribution network detection equipment.