What makes a Visualizer?
Visualizers are made up of numerous components that vary from model to model. Below is a list of the general components you would likely find on a visualizer followed by a brief description of each.
- Arm or Column
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There are two types of columns the gooseneck and the rigid arms are generally used in visualizers today.
The Gooseneck column is extremely maneuverable by positioning the camera head over, around and across the subject being viewed. Once the column is in place it will maintain its position. The column attaches to the camera head and to the base accommodating any cables. This type of column is particularly useful for displaying subjects through microscopes as the camera head can be positioned strategically over the eye piece.
Rigid columns are fixed arms which attach the camera head to the base with appropriate cables running through the column. They come in either fixed lengths or telescopic variants.
Rigid columns are fixed at the base usually with a hinge assembly, which allows the camera to be folded down for portability or to be brought down for better viewing of the subject on the base stage.
Back to the Top - Base
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The Visualizers base serves two functions. Firstly it creates a firm footing to make the visualizer stable to ensure that it will not topple over. Secondly the base usually houses the base light, main power, control panels, stage, input/output connections and processing circuitry. In some Visualizers the camera can be housed in the base, particularly with WolfVision models
Back to the Top - Base Lights / Light boxes
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Base lighting, where fitted, is designed to illuminate viewing subjects from behind, such as transparencies and vary in size from 127 x 100mm up to A4 (approx. 297 x 210mm). Normally the light box is constructed out of two Cold Cathode Fluorescent Lamps located either side of the lighting assembly which allows an even spread of light across the entire surface.
Optional accessory light boxes are also offered in a number of cases when they are not integral to the Visualizer.
Back to the Top - Camera
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The main part of any Visualizer is the camera, which will determine what is seen by the Visualizer and the level of image quality. The camera will consist of an image sensor and will usually be either a CCD or CMOS Active Pixel Sensor. Progressive Scan CCD technology is applied in certain models. Important to the quality of the image is the lens array on front of the image sensor and coupled with the resolution of the image sensor. This can make the difference between a good picture and a great picture. The majority of Desktop Visualizers will have a motorised zoom lens which makes it easy to select the correct view of the subject material.
Cameras are commonly located in a housing which will be fixed at a point to permit the camera to move on its axis. The degree to which that movement can be effected depends on the design of the visualizer. With gooseneck types the camera housing is either fixed or limited in movement about its fixing point as manoeuvrability is provided by the gooseneck itself.
Rigid column units commonly have their cameras in a housing attached to an assembly, which provides movement in the vertical axis up to a maximum angle of approximately 90° either side of the down looking position. This allows the camera to look away from the stage both forward and rearward (NB. Unless compensated for, the image will be upside down when looking away from the stage toward the position that the operator would normally stand. Few models provide compensation for this effect. When looking away from the operator the image will be the correct way up).
Depending on the construction and depth of field of the camera lens, Desktop Visualizers will be fitted with a "close-up" lens, which enables the camera to focus and magnify over short distances, i.e. down towards the stage. When viewing away from the stage at distanced objects, when the camera housing is rotated away from the stage, the close-up lens is redundant. Two common types of fixings for these lenses are either screw (similar to SLR camera lens filter fixings), or "flip-up" where the lens is housed in a narrow frame and fixed to the camera head by a hinge arrangement, closing over the main camera lens when close-up viewing is required, and opening or "flipping-up" when distance viewing is in use. Visualizers not fitted with a close-up lens do not require one due either to their design purpose or lens construction.
Camera heads can also contain wireless remote control receivers to maximise the visibility for reception of signals from the handheld transmitter.
Units with a top mirror viewing function, accommodate their cameras in the base, as with Wolf Vision, or on the column. Wolf Vision provide a motorised top mirror assembly in their two top Desktop models which also provide the image scrolling effect.
Back to the Top - Ceiling Visualizers
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do not conform to the norm, due to their very nature. They will contain a camera, motorised zoom lens and provide connectivity, but will include ceiling mounting capability and remote control functionality will play a far more crucial role. Where necessary their housings will be plenum rated for fire resistance in ceiling voids.
Back to the Top - Control Panel
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Control panels of Visualizers are strategically located for ease of access and use and usually to avoid the camera being obscured by the operator's arm in use.
Desktop Visualizers usually have control panels located at the front of the base stage or on the camera head. Their size and complexity depend on the degree of functionality offered. The majority are push-button and some include "jog shuttle" type controls, all are designed to be intuitive to allow the first-time user to start operation within seconds of introduction to the unit.
Back to the Top - Input / Output Panel
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With the exception of USB-only connected units, connector panels are usually located at the rear and/or the side of the visualizer base and their size depends on the functionality and features of the unit. They can be limited to a single connector or provide full connectivity to suit any display type or resolution.
Commonly provided connectivity on Visualizers is: D-sub 15 pin VGA, S-Video (4 pin Mini DIN), Composite Video (RCA/Phono) and BNC. DVI is beginning to appear in some models and offers High-Definition multimedia Interface (HDMI) in the case of Wolf Vision. Audio connectivity is provided by: Mini Jack or RCA/Phono. PC connectivity is provided almost exclusively by USB 1.0/1.1 (12 Mbits/second) or USB 2.0 (up to 480 Mbits/second). Network Connection 8P8C commonly referred to as RJ-45 ports are also available for PC networking connectivity in models from Wolf Vision.
Back to the Top - Overhead Lights
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Where lights are fitted they can vary in size, type, output and number. Several manufacturers choose LED technology due to intensity, colour temperature, cost and lifespan. Others use CCFL (Cold Cathode Fluorescent), standard Fluorescent or Halogen lamps which are equally as efficient.
Lamps can be mounted on separate smaller columns fixed to the side of the unit's base, at the hinge point of the main column or integral to the camera head itself. Usually lighting is designed to offer directional control which varies the amount of light from the subject reaching the camera. This directional adjustment enables optimum illumination of the subject to be achieved and helps in diminishing the occurrence of "hot spots" or "white outs" and is achieved by gradual rotation of the light unit and the angle of adjustment of the arms they are mounted to.
Back to the Top - Projector Integrated
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Two models in this section are currently available from Toshiba, which provide visualisation and projection in one box.
With the Toshiba product the camera, which is attached to the projector's side body, has a 3x Megapixel CMOS image sensor and 8x digital zoom with LED illumination. The fully featured projector uses LCD technology and has a brightness of 2000 ANSI Lumens with an output resolution of 1024 x 768 XGA.
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