Exposure amplifier 6 zone
Laser radiation safety is the safe design, use and implementation of lasers to minimize the risk of laser accidents, especially those involving eye injuries. Since even relatively small amounts of laser light can lead to permanent eye injuries, the sale and usage of lasers is typically subject to government regulations. Moderate and high-power lasers are potentially hazardous because they can burn the retina , or even the skin. To control the risk of injury, various specifications, for example 21 Code of Federal Regulations CFR Part in the US and IEC internationally, define "classes" of laser depending on their power and wavelength. These regulations impose upon manufacturers required safety measures, such as labeling lasers with specific warnings, and wearing laser safety goggles when operating lasers. Thermal effects are the predominant cause of laser radiation injury, but photo-chemical effects can also be of concern for specific wavelengths of laser radiation.
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Mixer PA Amplifier 6 Zone Paging MA 120Z6 100V 120W
A number of light measuring elements are arranged at various portions of an image of an object focused by an objective. The light measuring elements are grouped for different zones to measure the average brightness of the image within the respective zones. The average brightness of the image is weighed and added together to calculate the brightness of the object based on which the exposure is controlled.
The present invention relates to an exposure control method and a device therefor for use in a photographic camera, a motion picture camera, a television camera or the like, and more particularly to a method of controlling exposure for such an optical instrument in which the exposure is controlled based on the brightness of a focused image of the object to be photographed and an exposure control device for carrying out the method. There have been known an average light measuring system in which one or two light measuring elements are used for measuring the brightness of the image of an object as a whole and a central spot light measuring system in which the central portion of the image is particularly measured.
Further, recently it has been known to use a number of light measuring elements to measure the various portions of the image and detect the maximum and minimum brightness of the image to control exposure based on the maximum or minimum brightness or average brightness calculated therefrom. The above-mentioned conventional methods of exposure control suffer from defects in that the obtained exposure becomes under or over depending upon the specific brightness distribution of the image as of back-light image or scene having a dark background.
The object of the present invention is, therefore, to provide a method of controlling exposure in which proper exposure can be obtained even when the image has uneven distribution of brightness. Another object of the present invention is to provide a device for controlling exposure carrying out the above method of exposure control. Still another object of the present invention is to provide a method of controlling exposure in which proper exposure can be obtained for various kinds of images by changing the light measuring mode depending upon the object.
A further object of the present invention is to provide a method for controlling exposure in which proper exposure can be obtained for various positions of the camera or the like by changing the light measuring mode depending upon the position of the camera.
A still further object of the present invention is to provide an exposure controlling device for carrying out the above methods in which proper exposure can be obtained for various kinds of objects and for various positions of the camera or the like.
The above objects of the invention are accomplished by dividing the light measuring range of an image of an object into a number of zones, arranging at least one light measuring elements in the respective zones, obtaining the average brightness of the image in the respective zones Bmi , calculating the object brightness B based on the average brightnesses Bmi by the formula: EQU1 K.
The average brightness Bmi is obtained by dividing the sum of the log-converted value of the measured brightness by the number of light measuring elements in the zone, or by obtaining the average of the brightness measured by the light measuring elements in the respective zones and log-converting the sum.
Therefore, there is no fear that the brightness is effected by the high brightness portion of the object as experienced in the conventional central spot light measuring system. The present invention is advantageous in that the most desirable complex zone pattern can easily be selected for the given object and further the average brightness of the respective zones can be properly weighted by use of proper weighting coefficients, and accordingly the exposure control can be conducted more properly than any conventional method.
The present invention is further advantageous in that the zone pattern can be changed for different scene of the object. For instance, in case of a spot light illuminated object, the image area is divided into concentric zones distributed around the center of the image, and in case of an object in back light the area is divided into zones distributed concentrically around a point a little below the center of the image area. Further, it is possible to change the weighting coefficients for the respective zones for different scenes of the object.
For instance, in case of a spot light illuminated object, the central zones are provided with larger weighting coefficients, and in case of a back light object the marginal zones are provided with smaller coefficients. Furthermore, it is possible to obtain a whole average brightness Bo averaged throughout the whole image and use the same for correcting the exposure by adding the same to the above brightness Bmi after weighting the former.
In case that the zone pattern is asymmetrical and the position thereof changes as the position of the camera changes, the position of the camera is detected to correct the position of the zone pattern so that the zone pattern may properly be applied to the object image even when the camera position is changed.
Now the present invention will be described in detail with reference to the accompanying drawings. Referring to FIG. The light measuring elements 2a to 2n may be in the form of photodiodes, photovoltaic elements, phototransistors, CdS, photo-charge storing type CCD charge coupled device and the like. Since the CCD has a narrow dynamic range, it is desirable that the storing time be changed according to the brightness of the object to control sensitivity. In this example, an objective 3 is located in front of a light measuring portion 5 with the intervention of a stop 4 located therebetween.
A taking lens 6 is provided separately therefrom in parallel thereto to focus an image on a photographic film 8 through a stop 7. Thus, the light measuring portion 5 measures the light from the object not shown to be photographed by the camera with the taking lens 6.
An objective 9 is provided in front of an eyepiece 11 with the intervention of a semi-transparent mirror 10 located therebetween. The semi-transparent mirror 10 reflectes a part of the light coming in through the objective 9 toward the light measuring portion 5a. A part of the swing-up mirror 14 is made transparent to transmit the light coming in from the taking lens A concave mirror 15 is located behind the mirror 14 to reflect the light transmitting through the mirror 14 downward toward the light measuring portion 5b.
A stop 17 is located behind the taking lens Thus, a part of the light coming in through the taking lens 16 is focused on the light measuring portion 5b and forms a small image of the object to be photographed thereon. The mirror 14 reflects the light coming in from the taking lens 16 upward.
The light reflected upward by the mirror 14 enters a pentagonal prism 18 through a focusing glass 19 and a condenser lens The light measuring portion 5c is located above the prism 18, 5d in front thereof and 5e therebehind.
In front of the respective light measuring portions 5c, 5d and 5e are located focusing lenses 21c, 21d and 21e, respectively. The light measuring portion 5 as mentioned hereinabove is provided with a number of light measuring elements 2a, 2b,.
In the example shown in FIG. The former three make one zone and are grouped together and the latter three make another zone and are grouped together. By dividing the light measuring elements 2a, 2b,.
Further, by dividing the area into more zones, the area can be divided as shown in FIGS. In the example as shown in FIG. Since the brightness of the marginal portion of the image is low due to the optical performance of the objective or the taking lens, the output of the light measuring elements located in the marginal region of the focused image is low.
Therefore, it is desirable that the light receiving area of the light measuring elements located in the marginal portion or the area of the zone in the marginal portion be made larger than that of the central portion. The zone pattern as shown in FIG. Therefore, the pattern does not change with the position of the camera. The exposure control method and device in accordance with the present invention employs the light measuring portion 5, 5a, 5b. Now the exposure control circuit connected with the light measuring portion employed in the present invention will be described in detail with reference to FIG.
The photodiodes 2a, 2b,. The operational amplifiers 25a,. The gain is controlled to provide a weighting coefficient for the averaged value of the outputs of the light measuring elements in the zone. The weighted output signals of the zones weighted by the operational amplifiers 25a. In this embodiment the averaged values are all summed up. However, it is possible to subtract one output signal of a light measuring zone from the sum of the output signals of the other light measuring zones.
For example, when the image includes a bright sky, it is possible to subtract the output of the zone corresponding to the sky from the sum of the outputs of the other zones. The output of the operational amplifier 29 is sent to an exposure computing circuit 31 as the object brightness information, where a photographic calculation is conducted together with a film sensitivity and the like from an exposure information input means The output of the exposure computing circuit 31 controls the shutter control circuit 33 or the aperture control circuit 34 connected thereto.
In the above embodiment as shown in FIG. However, the photodiodes may be connected after amplified by amplifiers. At the same time, the photodiodes 2a. Thus, the output of the photodiodes 2a. The output signals of the operational amplifiers 36a. The resistors 38 and 39 connected before and in parallel to the operational amplifier 37 are used for weighting the averaged value of the output signals.
The light measuring portion 5 is divided into four zones 5. The log-conversion circuit 40 is constituted of a set of operational amplifiers and log diodes connected in the feed-back circuit thereof for the respective light measuring elements 2a. The log-converted signals are inputed into adding circuits 41a. As the adding circuits 41a.
The output signals of the adding circuits 41a. By this division, the average brightness Bmi for the respective zones is calculated. The average brightness thus obtained is inputed into a weighting adding-and-subtracting circuit 43 and addition and subtraction are conducted after being weighted. Thus, the operation of the formula 1 is conducted by the circuit 43 to calculate the object brightness B.
The brightness B thus obtained is inputed into the exposure calculating circuit Since the zones are divided into asymmetric pattern with respect to the horizontal central line, the position of the zones change as the position of the camera changes. The light measuring elements are numbered 1 to In the position of FIG. In FIG. The output of the light measuring portion 5 is first log-converted by a log-conversion circuit 40 and then inputed into a matrix circuit The matrix circuit 44 makes three groups each consisting of two groups for the three different positions.
In more detail, in case of FIG. In case of FIG. Similarly, in case of FIG. The outputs of these adding circuits 45a,45b,46a,46b,47a and 47b are inputed into dividing circuits 48a,48b,49a,49b,50a and 50b, respectively. The dividing circuits divide the summed value by the number of the light measuring elements in each zone.
The average brightness is thus obtained for three kinds of zone pattern for three different positions of the camera. One of the three average brightness outputs is selected according to the position of the camera by means of an analog switch The analog switch 51 is connected with a camera position detecting means 52 and one of three sets of switches 51a,51b, 51c,51d, and 51e,51f is turned on according to the detected position of the camera.
When the camera is in the horizontal position, analog switches 51a and 51b are turned on to transmit the output of the dividing circuit 48a and 48b to a brightness calculating circuit When the camera is held with the left side up, the analog switches 51c and 51d are turned on and when right side up the switches 51e and 51f are turned on.
The circuit 43 is connected with an exposure computing circuit A Y-shaped glass tube 54 is filled with mercury The mercury 55 moves within the glass tube 54 as the position of the camera changes.
When the camera is held horizontally, the mercury 55 stays in the lower section of the Y-shaped glass tube 54 as shown in FIG. When the camera is moved to the left side up position in FIG. The coefficients Ki for the formula 1 for the other examples of the zone pattern may be determined as follows for example. For the example as shown in FIG. For the example as shown in FIGS.
Exposure XI 11 Pre Amplifier Pre Amp Stereo By John Farlowe Great Condition
A number of light measuring elements are arranged at various portions of an image of an object focused by an objective. The light measuring elements are grouped for different zones to measure the average brightness of the image within the respective zones. The average brightness of the image is weighed and added together to calculate the brightness of the object based on which the exposure is controlled. Field of the Invention. The present invention relates to an exposure control method and a device therefor for use in a photographic camera, a motion picture camera, a television camera or the like, and more particularly to a method of controlling exposure for such an optical instrument in which the exposure is controlled based on the brightness of a focused image of the object to be photographed and an exposure control device for carrying out the method.
Laser safety
Particle and Fibre Toxicology volume 15 , Article number: 44 Cite this article. Metrics details. Effects of air pollution on neurotoxicity and behavioral alterations have been reported. The objective of this study was to investigate the pathophysiology caused by particulate matter PM in the brain. The rats were exposed to An MRI analysis showed that whole-brain and hippocampal volumes increased with 3 and 6 months of PM 1 exposure. A short-term memory deficiency occurred with 3 months of exposure to PM 1 as determined by a novel object recognition NOR task, but there were no significant changes in motor functions. There were no changes in frequency bands or multiscale entropy of brainwaves. Exposure to 3 months of PM 1 increased 8-isoporstance in the cortex, cerebellum, and hippocampus as well as hippocampal inflammation interleukin IL -6 , but not in the olfactory bulb. Light chain 3 LC3 expression increased in the hippocampus after 6 months of exposure.
Sherbourn LDS 12/900 12-Channel 6 Zone Power Amplifier
Color: White, Chime button for making announcements, 10 oz, 6-Zones of speaker outputs - each zone has a separate volume control, SD card slot to play music stored on an SD Card. Echo control for the mic inputs with speed and repeat adjustments. Quality and luxury at the highest levels are the result of honing and perfecting time-honored traditions, skills and knowledge through the years. From a simple gift for a loved one to custom jewelry fit to become beloved family heirlooms, our dedicated team gemologists, craftsmen and industry professionals will walk you through every step of the process.
Available Wiring Diagrams
Little is known about how individual neurotransmitter systems are differentially utilized in response to the ever-changing acoustic environment. Sound exposure upregulates tyrosine hydroxylase, an enzyme responsible for dopamine synthesis, in cholinergic LOC intrinsic neurons, suggesting that individual LOC neurons might at times co-release ACh and DA. We further demonstrate that dopamine down-regulates ANF firing rates by reducing both the hair cell release rate and the size of synaptic events. Every day, we hear sounds that might be alarming, distracting, intriguing or calming — or simply just too loud. Our hearing system responds to these acoustic changes by fine-tuning sounds before they enter the brain. For example, if a noise is too loud, the volume can be turned down by dampening the signals nerve fibers in the ear send to the brain.
Is mobile phone tower radiation a health hazard?
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Functional Notes: Operational condition of this item is excellent, fully tested and no issues found. For all other locations including Hawaii, Puerto Rico and Alaska, please request a quote prior to purchase. Items with factory packaging will be double boxed.
Amplifier top mounted controls include our C. Upgraded input RCA connectors allow for high or low level input signal to be used through our differential input circuit which eliminates incoming noise and can provide a remote out signal when using high level inputs. Dual fan cooling, real time thermal monitoring and dual extruded heat sinks maintain heat dissipation even at high outputs keeping the amp cool. Other features include a conformal coated circuit board for protection against element exposure and compatibility with our PLC2 level remote control. This design creates a highly efficient design that reduces the electrical impact on the vehicles charging system by using the efficient Class D technology while maintaining fidelity combining it with Class b topology.
A number of light measuring elements are arranged at various portions of an image of an object focused by an objective. The light measuring elements are grouped for different zones to measure the average brightness of the image within the respective zones. The average brightness of the image is weighed and added together to calculate the brightness of the object based on which the exposure is controlled. The present invention relates to an exposure control method and a device therefor for use in a photographic camera, a motion picture camera, a television camera or the like, and more particularly to a method of controlling exposure for such an optical instrument in which the exposure is controlled based on the brightness of a focused image of the object to be photographed and an exposure control device for carrying out the method. There have been known an average light measuring system in which one or two light measuring elements are used for measuring the brightness of the image of an object as a whole and a central spot light measuring system in which the central portion of the image is particularly measured. Further, recently it has been known to use a number of light measuring elements to measure the various portions of the image and detect the maximum and minimum brightness of the image to control exposure based on the maximum or minimum brightness or average brightness calculated therefrom.
Does radiation from cellphone towers cause cancer? Yes, said the Kasliwals, two of who have been diagnosed with brain cancer after three towers were installed next to their upscale C-scheme neighbourhood in Jaipur. Since then, illnesses, both minor and major, have become a part of their lives and the lives of the 50 other families in their neighbourhood. The Kasliwals have no family history of cancer.
I apologise, but, in my opinion, you are not right. I am assured. Let's discuss. Write to me in PM, we will talk.