Posts Tagged ‘ LEDs’



Dome Security Camera

Written By:
Friday, April 1st, 2011

The dome security camera is one of the most popular types of digital video security camera in use today.  Thanks to modern technological advances a lot of electronic power can be packaged inside a small 3.5 inch diameter dome camera.  Not only are they small and powerful, but the average dome security camera is light weight as well (in most cases weighing just under one pound), which makes it easy to mount just about anywhere.

Today, there are three standard types of digital video camera based on shape; the box type, bullet type, and dome security camera.  How, what, and where the camera is used usually dictates the type, although user preference is also a factor.

Dome cameras originated from their older analog ancestors.  These cameras were often big and bulky and required a great deal more depth than today’s dome security camera.  Often, the older cameras were actually box cameras placed behind a wall or ceiling with the body of the camera extending into the wall space ith just the lens extending through a pre-cut opening.   A glass dome was then fixed over the lens to make it more aesthetically pleasing.  Blackened glass or two-way mirror glass was often used to conceal the lens, so that potential shoplifters, intruders, etc. would not know in what direction the lens was aimed.

Current dome security cameras are nothing like what is described in the previous paragraph.  Considering that the main components of a digital video camera are the lens, the sensor chip, and the Integrated Circuit (IC) electronics the largest part of the camera is often the lens which on the average is about 3.6mm in diameter.

A digital video dome security camera is a compact, highly sophisticated electronic piece of equipment.   The sole purpose of the camera is to transfer light images into electronic images that can be seen on an electronic display device such as a monitor.

It does this by first using a lens to focus the field of view onto a tiny sensor chip.  These chips range from 1/3 inch to about 1/2 inch square.  One of two different sensor ships is used.  Although the chips go about the process differently, both yield the same result; transferring light into electronic impulses that can be measured (and therefore used to create an electronic image).

The sensor chips are either a Charged Coupled Device or CCD or a Complementary Metal Oxide Semiconductor or CMOS.  After the sensor chip converts the light image into an electronic impulse, the IC chips take over processing and digitizing the electronic information and passing it along to the Digital Video Recorder or DVR.

There are several types of dome security cameras based on how they function or where they are intended to be used.  Dome security cameras can be classified as indoor, outdoor, or indoor/outdoor types although most outdoor types today are the combination indoor/outdoor.  Indoor dome cameras are intended to be used inside, under protective cover from the weather and other elements.

Outdoor dome security cameras are protected by an outer shell or case that prevents water, snow, hail, or other damage to the camera itself.   These cameras are often rated according to the International Electrotechnical Commission’s (IEC’s) Ingress Protection or IP standard.   An IP rating of IP55 or higher is usually considered good.

Dome security cameras are usually flush mounted on a ceiling or wall, but may be mounted on special mounts that can range from peduncle type to horizontal extensions.  They require very little surface area for mounting, and can usually be mounted easily using from two to four screws.  The video transmission cable and the power supply cable usually attach from the underside of the mount or there are extensions exiting from under the mount such that the wires remain hidden and protected by the structure the camera is mounted on.

Dome security cameras may also work in InfraRed (IR) modes and the IR Light Emitting Diodes or LEDs are normally clustered right around the camera lens.   This provides directed IR illumination in the exact field of vision of the camera lens.

Security Camera King offers a wide selection of indoor and outdoor (as well as indoor/outdoor) dome security cameras.  Our cameras are of the highest quality and offer the best performance at the most economical price in the industry.

facebooktwittergoogle_plusredditpinterestlinkedintumblrmail

Home Security Gate Camera

Written By:
Tuesday, January 4th, 2011

A home security gate camera can alert to you to approaching visitors long before they reach your door, prevent unwanted and unnecessary solicitors and assist in providing gate access control.

Home owners often start their residential digital video camera security system with a single home security gate camera. However, after using this camera for a while and realizing the potential security and monitoring power of a digital video camera, they usually return to purchase an entire digital video security system for the house and residential property. This is easy to do as there are systems that easily support up to four, eight, or even sixteen individual cameras.

A home security gate camera used in tandem with a remote electronic gate lock and opener can provide you with security guard “like” control of your property’s entrance. This can be accomplished by using a digital video security camera with audio capturing technology (or an intercom) and either a wired or wireless electric gate lock and opener.

When a visitor arrives at the gate entrance, the user can look at the security system monitor to see the individual’s face and/or the vehicle they are driving. Once the home owner has identified the visitor, they can press the remote gate lock and opener button to allow the individual to enter the property.

For individuals with large homes on abundant land and long driveways, this feature is particularly useful for controlling access to the residence. Some may want to modify the system a bit and use a two-way intercom so that a conversation can take place between the user and a visitor if need be.

There are some features available that you may want to consider before purchasing your home security gate camera. First and foremost, the camera must be an outdoor type camera. These cameras are specifically made with an enclosure or case that provides protection from the weather and elements. These cameras often utilize the International Electrotechnical Commission’s Ingress Protection or International Protection (IP) code.

The IP code consists of two digits, with the first digit representing protection from solids and the second digit representing protection from liquids; the higher the number of each digit the better the protection. The ranges of digits are 0-6 for the first digit and 0-8 for the second digit. An outdoor camera with a rating of IP55 or greater should work fine.

If you want a camera that can capture images ’round the clock (24/7), you may want to consider providing flood lighting at the gate for night time monitoring. However, a cheaper and much easier alternative is to use a home security gate camera that has infrared night vision.

Night vision infrared cameras work both in daylight and in darkness. The camera is sensitive to near infrared spectrum radiation “light.” The infrared light is provided by on-board infrared producing Light Emitting Diodes or LEDs. These LEDs are normally arranged in an array around the camera lens so that they provide a floodlight of infrared illumination in the camera’s field of view. This light is invisible to the human eye, but visible to the camera.

If you are interested in monitoring more area than just the gate or visitor, you may also want to consider a Pan-Tilt-Zoom (PTZ) camera. These cameras can be remotely controlled by the homeowner to move horizontally or vertically to increase the camera’s field of view. Images can be enlarged by using the zoom function. Many DVRs (Digital Video Recorders) have programming that can automatically control PTZ cameras to track or follow objects.

Whether you have the security system installed by a professional or are installing it yourself, you may also want to consider a wireless, battery operated camera. Digital video cameras require that an RG-59 type coaxial video transmission cable be run from each camera to the DVR unit (or monitor if no DVR is used). In addition, each camera needs a low-voltage DC wire run to it for a power supply. A wireless, battery operated camera eliminates the need for any cabling and makes installation a snap.

There are a lot of choices for someone looking to purchase a home security gate camera. Today’s technological advancements have yielded a large variety of optional features that have made home security gate cameras even more powerful, providing the protection you need.

facebooktwittergoogle_plusredditpinterestlinkedintumblrmail

640 x 480 Infrared Camera

Written By:
Monday, October 11th, 2010

What exactly is a 640 x 480 infrared camera? This can be a complicated answer for many reasons. In the following article we will attempt to address some of the characteristics that can make this seemingly simple question so complicated. Specifically, we will briefly discuss infrared technology and the reference to display resolution and how they relate to a 640 x 480 infrared camera.

First lets discuss the meaning of “infrared” when we talk about a 640 x 480 infrared camera. The term “infrared” refers to the wavelength of electromagnetic radiation. The wavelength of infrared radiation generally ranges between 0.7 and 300 micrometers abbreviated as “µm.” The exact range and categories defined may vary slightly depending on the scale that is used to describe the radiation.

For our purposes, it is sufficient enough to know that infrared radiation is a longer wavelength than visible light, therefore the human eye cannot see it. Further, there may be several categories of infrared radiation based on wavelength but we will only consider two; “near infrared” radiation which is invisible to the human eye but is the closest in wavelength to radiation that is visible to the human eye) and “long-wavelength” also called “far infrared,” which for our discussion is the thermal imaging region which is naturally emitted by objects and requires no external or artificial illumination.

So, on this basis there are essentially two types of 640 x 480 infrared cameras. The first type, and the one most commonly used in digital video security camera systems, is the near infrared camera. This camera contains one of two electronic sensor chips, either a Charged Coupled Device (CCD) or a Complimentary Metal Oxide Semiconductor (CMOS). These sensors are able to convert the light energy into electrical energy that can be measured, thereby creating a digital image. Fortuitously, these sensors inherently detect near infrared radiation as well.

The near infrared 640 x 480 camera uses external infrared radiation (or infrared light) to illuminate the area in its field of view. These cameras use InfraRed Light Emitting Diodes or IR LEDS to illuminate the target area in order to create an image. The IR LEDs are normally configured in an array that surrounds the camera lens so that they are focused in the same direction. However, some cameras may have IR LEDs clustered off to the side of the lens and there are even separate “illuminators” that contain nothing but IR LEDs and can be mounted and aimed separately from the camera.

These cameras normally produce a color image in visible light conditions and when the visible light is not bright enough to produce a high quality video image, they switch to infrared, producing a monochromatic or black and white video image.

The far infrared 640 x 480 infrared camera does not require additional external infrared illumination. This camera uses an infrared “Focal Plane Array” or FPA sensor and is capable of creating a digital video image based solely on the thermal emissions or “heat signatures” of objects. These cameras are often called “Forward Looking InfraRed” or FLIR cameras. These cameras are also often made in a “hand held” version. Older models of these cameras had to be cooled somehow to prevent the users’ and their own thermal emissions from interfering with the image.

Far infrared 640 x 480 infrared cameras are often used not only for covert surveillance and security, but by inspectors and engineers to detect a variety of heat signatures. These cameras can be used to detect areas of heat “leakage” from a building or “hot spots” on mechanical engines and other devices.

As for the reference of “640 x 480″ in a 640 x 480 infrared camera, this refers to the image resolution in pixels that the camera is capable of displaying. Far infrared cameras are more commonly referred to by their resolution in pixels, i.e. 640 x 480 infrared camera. However, digital video security cameras may also use the same description.

This can be confusing because older, analog security video cameras more commonly referred to their resolution in terms of TVL or Television Lines. Since the security camera industry today uses primarily digital video cameras, they may refer to the resolution in terms of TVL or pixels.

Perhaps the easiest way to tell the difference between the two is the price. Near infrared digital image security video cameras can be purchased for as low as less than one hundered while far infrared FLIR cameras range from one to several thousand dollars.


facebooktwittergoogle_plusredditpinterestlinkedintumblrmail

Infrared Digital Camera Lens

Written By:
Wednesday, September 29th, 2010

Do security cameras need infrared digital camera lenses to produce infrared video images? How does an digital video infrared camera produce infrared images?

Before we attempt to answer any of these questions, let’s discuss how digital video security cameras work to fully understand their function and how it can relate to infrared image production.

First, a typical contemporary security camera is a digital video camera versus the older legacy analog video cameras. Digital video security cameras are very similar to digital photograph cameras, except that digital video cameras take several digital photographs within a very short time period. On the average, good quality digital video cameras will work at speeds of 30 photographs per second also known as 30 frames per second or 30 fps. Photographs taken at this speed rate, when displayed at the same rate, appear to the human eye as smooth, fluid video.

Digital video security cameras create digital images by using one of two different sensors that transfer light energy into electrical energy that can be measured and used to create a digital video image. One of the sensors is called a Charged Coupled Device or CCD and the other is a Complimentary Metal Oxide Semiconductor or CMOS. These sensor chips are relatively small and for most digital video security cameras range from about 1/4″ to 1 inch in diameter. Generally, but not always, the bigger size of the chip produces a higher resolution image.

The interesting thing about both chips is that they are inherently sensitive to infrared radiation in the near infrared spectrum. No infrared digital camera lens is needed for them to sense near infrared radiation or “light.” This type of infrared radiation is invisible to the human eye however so we cannot detect it. As an example most appliance remote controls (televisions, DVD players, cable TV boxes, etc.) operate by using infrared signals. (Try looking at your remote while pressing a command button – you should see nothing, then look at it again through your digital camera – you should see a flashing white light.

As you can see, your camera is already able to detect near infrared spectrum radiation, so realistically no infrared digital camera lens is required. This is a great value-added feature of the CCD and CMOS sensor chips.

Near infrared radiation is not normally emitted by all objects, i.e. it is not the same wavelength of infrared light that comprises object’s heat signatures. Therefore, your infrared digital video camera needs infrared illumination of the field of view in order for it to produce an image. This is accomplished by using several InfraRed Light Emitting Diodes or IT LEDs to illuminate the field of view. Generally, the more LEDs that are used, the longer the infrared range of the camera.

Therefore it is not necessary to used an infrared digital camera lens to make your digital camera take infrared video images. However, it is necessary for the target area to be illuminated with near infrared spectrum light, so IR LEDs or other infrared illumination is required.

One thing about this business of infrared digital camera lenses and imagery. Security cameras are often marketed as day/night or true day/night cameras, meaning they can take high quality color digital video in visible light conditions and high quality black and white or monochromatic digital video in dark conditions (infrared light does not express “colors.”)

A typical day/night camera uses software or circuitry to filter out the infrared light that it picks up during visible lighting conditions. If it didn’t the extra infrared radiation would combine with visible light to make a lesser quality image. True day/night cameras however, have an internal filter that is used during visible lighting conditions to filter out the infrared light.

This filter is often called an IR Cut Filter (InfraRed Cut-off Filter). It produces a much cleaner, brighter, and higher quality video image. Under infrared conditions, the filter is mechanically removed to allow penetration of infrared light to the sensor. Generally, “true day/night” cameras are more expensive because they contain this filter and the mechanism to remove and replace it.

So as you can see, digital video security cameras by the nature of the electronic sensor they use, can already detect infrared radiation without the need for an infrared digital camera lens. In fact, IR LEDs are more likely needed to create IR light and filters are needed to suppress the infrared radiation during visible light periods to produce a higher quality image.

facebooktwittergoogle_plusredditpinterestlinkedintumblrmail

Camera Mounted Infrared Illuminator

Written By:
Monday, August 2nd, 2010

A camera mounted infrared illuminator is used with most night vision infrared digital video surveillance and security cameras to provide invisible light that is used to create an infrared digital video. The illuminator is normally aimed in the exact same direction of the camera lens so that it can provide infrared light beams to illuminate the target area. Infrared illumination can be “seen” by the camera, but cannot be seen by the human eye.

Let’s take a closer look at how a night vision infrared digital video security camera works in order to appreciate the need for the camera mounted infrared illuminator.

A night vision infrared digital video security camera can produce high quality color video footage when there is enough visible light present. When there is not enough visible light present or when in total darkness, a sensor on the camera switches it into the infrared mode. Digital video recorded under the infrared mode is high quality video footage as well, but is monochromatic or black and white, since infrared light does not emit color.

These cameras create a video image by using one of two sensors that convert light energy into electrical energy that can be quantified and used to create a digital video picture. The sensors that are normally used are the Charged Coupled Device or CCD, or the Complimentary Metal Oxide Semiconductor or CMOS. The camera lens focuses the light from the image onto the sensor which then converts the light image into an electronic image which can be viewed on a monitor or stored as a digital video file.

Both the CCD and CMOS can be constructed with various sensitivities to light. Some cameras can produce full-color, high quality digital video with as little as .002 lux or less of light. These cameras are usually called day/night vision cameras and still require visible light to operate properly; they are infrared sensitive cameras.

A camera mounted infrared illuminator is required on night vision infrared digital video cameras to provide plenty of “light” to illuminate the subject. However, in this case the light is actually infrared radiation from the near infrared spectrum. This light or radiation has a similar effect as a flood light or spot light would on a normal visible-light digital video camera.

Most camera mounted infrared illuminators are created from several infrared Light Emitting Diodes or LEDs. The LEDs are able to create a sufficient amount of radiation that can be focused in the direction of the camera’s field of view. The advantage of using LEDs is that they use a relatively low amount of electrical energy and are small and compact.

The LEDS are normally arranged in an array that surrounds the outside of the camera’s lens or is in a grouping off to the side of the lens but aimed in the same direction as the camera. Generally the more LEDS used the greater the angle and the longer the distance of the effective infrared field of view. For this reason, every night vision infrared digital video camera has an effective target range.

If you are considering the purchase of an infrared night vision camera, be certain that the camera matches the range that you need for the job. There are a variety of different cameras available based on their effective range. Range values for cameras usually begin around 20 to 30 feet with cameras that have ranges of up to 200 feet or more. Cameras are more expensive for higher ranges, because of the extra LEDs that are used for the camera mounted infrared illuminator.

Some cameras ranges and angle of field of view can be extended by using additional infrared LED illuminators. However, these are not camera mounted infrared illuminators; they are mounted separately on their own and must be manually adjusted to ensure that they are aimed properly at the field of view of the camera.

Camera mounted infrared illuminators are an integral and necessary component of any infrared digital video camera. They supply the infrared “light” or radiation that is needed to illuminate the target area for the camera. Normally, the source for this radiation is an array of infrared LEDs that surround the camera lens or are located on the camera. Additional LED illuminators can also be purchased as accessories.

facebooktwittergoogle_plusredditpinterestlinkedintumblrmail