Lens centering

Let P be a point in a scene and let Pi and P2 be the points corresponding to P in two images obtained from two known sensor positions. Let the lens centers in these... 

From Figure 12.10, 5n is determined by the electric field difference between the lens center and the border. When a voltage V is applied to the lens cell, the electric field in the center (.Ecenter) d at the border (Eborder) is expressed as follows ... 

From Fresnel s approximation, the focal length of an LC lens is related to the lens radius r and Sn = ncenter-nborder which is the refractive index difference between the lens center and borders, as described in Equation (12.5). 

A simple camera-centered imaging model is shown in Fig. 19.38. The coordinate system is chosen such that the xy plane is parallel with the image plane and the z axis passes through the lens center at a distance /, the focal length of the camera, from the image plane. The image of a scene point (x,y,z) forms a point (x y ) on the image plane where... 

Lenses are coated with antireflecting films to increase the optical beam s energy through the instrument. These films are thickness and refractive index specific. IF they are touched, residual skin oils will adversely affect both film thickness and refractive index. The lens will then reflect more and transmit less. Dirty lenses should be cleaned with a fresh cotton-tip swab saturated with a 3 1 mixture of denatured alcohol and ether. Touch the swab to the lens center and then wipe in a spirUng motion to the edge. Rinse with denatured alcohol and allow to dry by evaporation. Do not attempt to clean coated lenses with silicon-coated lens tissues or cloths. The silicone will react with the antireflecting film to create a permanently clouded coating. 

A concave lens cavity model with heater and cooling chaimels as shown in Fig.l were utilized for the simulation and experiment. The heater was put in the vicinity of the lens center, and the cooling chaimels were put around the cavity. Fig.2 is the cut view of the meshed cavity and coolant chaimel. The lens part is meshed by the hexahedral element, and the coolant chaimels are meshed via the combination of prismatic element in the axial direction and the tetrahedral element in the juncture region. The mold base is meshed by the tetrahedral element except in the region adjacent to the coolant surface, where only pyramid element can be used. 

Poland s deposits tend to be located primarily in the west as isolated, lens-shaped deposits. There are other deposits in the center of the country at Turow, Konin /Goslawice/Patnow, Turek/Adomow, and Rogo2no. The production is used in power plants. 

Construction and Operation of Analyzer The construction principle of a sulfur dioxide analyzer based on the ultraviolet fluorescence principle is shown in Fig. 13.48. Undesired wavelengths are removed from the irradiating beam as tar as pos.sible using filters. The irradiating light 214 nm) is focused by a lens at the center of the reaction chamber. 

This system consists of a symmetrical pair of lens elements connected by a small volume of liquid. Each lens consists of a single spherical interface between the liquid and a lens rod. The lens element is formed by polishing a small concave spherical surface in the end of a sapphire rod. At the opposite end of the rod, a thin film piezoelectric transducer is centered on the axis of the lens surface. 

Figure 2 shows the brief principle of a laser-detected FFM. A sample is put on a piezoelectrical tube (PZT), which scans X, Y plane and controls the feedback of Z axis. The laser beam from a diode is focused on the mirror of the free end of a cantilever with lens, and the reflected beam falls on the center of a position-sensitive detector (PSD), a four-quadrant photodiode. When the sample contacts with the tip and relatively moves under the control of a computer, the reflected beam deflects and changes the position on the PSD due to the twist and deflection of the cantilever caused by the changes of surface roughness, friction force, and adhesive force between the sample and the tip. The extension and re-... 

Guidance for Industry Premarket Notification (510(k)) Guidance Document for Contact Lens Care Products. Center for Devices and Radiologic Health, FDA, Rockville, MD, 1997. 

We measured and analyzed the vertical emission from the resonators under pulsed optical pumping. The experimental setup is illustrated in Fig. 12.8a A Ti/sapphire mode-locked laser was used to optically pump the devices at a center wavelength of 980 nm, repetition rate of 76.6 MHz, and pulse duration of approximately 150 fs. A variable attenuator was used to control the pump power. The average pump power and center wavelength were monitored by a wavemeter, through a 50/50 beamsplitter. The pump beam is focused on the back side of the sample with a 50 x objective lens. A 20 x objective lens is used to collect the vertical emission from the sample and to focus it on an IR camera to obtain the NF intensity pattern and to... 

Spherical aberration Inacccurate focusing of light due to curved surface of lense whereby light rays passing through the lens at different distances from its center are focused to different positions in the Z-axis. 

Focal length This is the distance from the lens to the center of the focus. The greater the focal length, the higher the magnification, but the narrower the field of vision. 

The bulk appKTP crystal was 4 mm in length, and was not AR-coated. The grating periods varied from 4.1 pm to 4.3 pm in order to provide a fundamental bandwidth of 7 nm, for SHG at room temperature centered at 851 nm. With an experimentally-optimized focusing lens (f= 15 mm w =... 

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