Showing posts with label Optoma. Show all posts
Showing posts with label Optoma. Show all posts

Tuesday, February 27, 2018

What Makes a Projector? -DLP



Projectors have come a long way over the years.  At first they used film to feed through a mechanical shutter with the 2 large reels holding the film. Now they have become stand alone display devices.  More similar to a TV screen than a slide projector.

What makes them what they are today? There are essentially two answers to that question.  One is LCD technology and the other is DLP technology.  They both use replaceable lamps, but how they use those lamps to create the image is what sets them apart.

This begins a short series on Projector display technology.  This post we will cover DLP Projectors.

DLP is an acronym for Digital Light Processing. Invented in 1987 by Larry Hornbeck of Texas Instruments the digital mirrored device chip(DMD).




The first video projector to use this technology was built by Digital Projection in 1997.  Both Digital Projection and Texas Instruments won an Emmy Award for the use of DLP technology.







A DMD chip(pictured above) is made up of microscopic mirrors arranged in an array on the chip surface.  The mirrors are controlled via small electrostatic pulses to adjust their angle.  The angle causes them to either reflect the light out the lens onto the screen or away from the lens to create black or lack of light.  Each mirror is made up a microscopic yoke, torsion spring, and the electrostatic pads that affect the memory cells that set the position.


The diagram to the right shows the construction of each pixel.  Depending on the resolutions the amount of pixels changes. For instance an 800 x 600 DMD has (800*600 pixels= 480,000) pixels or mirrors that are controlled.  However some chips use a method of oscillating the mirrors to have them act double duty, halving the amount of mirror elements needed in a DMD chip.  

DLP Chips are monochrome or single colored. They can only turn light on and off and adjust its brightness. It cannot color the light.  This is where the next most important device of a DLP projector comes into play.

The Color wheel is a glass wheel made up of multiple segments all with a different color glass light filter.  On average they use 4 segments: red, blue, green and clear. Some models have multiples of the same color.  Others use 6 segments colors red, purple, blue, light blue, green and yellow.  The projector syncs the rotation of the color wheel and the color needs of the DMD while the image is being projected. DLP uses optical persistence to "fool" our eyes into seeing a mix of colors when in reality the projector is only projecting one color at a time for a fraction of a second.  If you blink your eyes quickly while looking at the DLP projected image, you can see the colors by themselves.

These 2 devices more than any other set the DLP projector apart from LCD.  Other differences are in the electronics.  There are a whole set of electronics that only are there to support and control the DMD chip.  These electronics are not as physically obvious but are no less important. These chips are for driving the electrostatic control signals to the DMD, as well as the video processing chips that prepare the signal to the DMD controller.  There is a motor control chip that keeps the color wheel in sync so that why the DMD is projecting the red portion of the image, the red color wheel segment is in position.  These all work together to ensure a pleasant and vibrant image.  

The main benefit of DLP over LCD(at the time) was the contrast ratio. Contrast ratio is the difference between a full white and full black image. When using a lamp to create an image there is almost no chance of having true black as black is the absence of light.  Turning off the lamp for the black portions of the picture is not practical.  Rather the pixels that require black merely point their light away from the main lens creating black on the screen.  Since the mirrors are only pointing away, there is some minor light leakage so the "blacks" are not as black as they could be.  The higher the ratio, the darker the blacks and brighter the white bits of the image will be. This was more of an issue with DLP first came to market as LCD had abysmal contrast.  These days they are pretty much the same contrast ratio-wise.

The last and most obvious difference is the lamp used in DLP.  Both DLP and LCD use Short ARC Mercury vapor lamps but only DLP uses this particular arrangement.

DLP Lamps commonly use a non-optical lens. Meaning there is no focusing or change in direction of the light beam.  Rather they have lenses inside the optics that do any light adjustment needed.  The lamps do have a special coating on the lens(ND filter lens). That coating prevents UV(ultraviolet) and IR(infrared) light from being injected into the light path.

DLP Lamp with UV/IR coating

LCD LampThese can harm your eyes and the optics due to heat and radiation.  This coating is a big reason why we do not recommend replacing only the bare bulb. If that coating fails or fails just a little it can cause your color wheel problems and possibly even melt some of the lenses.



Here is a picture of the internals from a Polyvision PJ905 that uses a 2002031-00 Lamp that has the proper coating.


PJ905 Internal diagram of DLP projector.


This about sums up the DLP video projector.  They are a reliable and well proven piece of technology.  Pureland Supply takes a lot of pride in our lamps and we make sure every lamp that is used in a DLP projector(as well as LCD) is configured correctly to perform as well as possible for you.  Check our selection of lamps here. 

Stay tuned for next week when we discuss LCD projectors. If you have any questions please do not hesitate to contact us at 1-800-664-6671 or Sales@purelandsupply.com








Friday, December 22, 2017

10 Tips to Prolong Lamp Life from Pureland Supply

Projector lamps are most important to your projector. Prolong their life with these tips.


1.  Handle the Projector Lamp with gloves. Oils and deposits from hands and fingers can cause hot spots on face of the Projector Lamp, which may result in premature Lamp failure.  Gloves also insure against any smudges that could get on the glass lenses or the projector or the lamp itself.

2.  Operate your projector in a clean, cool, and well ventilated area. A dust free environment would be ideal.  It may be advantageous to look into a ventilation system or air filtration system in the area that the projector will be operating in.

3.  Keep the projector air filters and air vents clean. Clogged filters/vents will not remove heat effectively. This can cause the projector to overheat with an early lamp failure.  During routine maintenance it is recommended to vacuum any loose debris and dust from the projector.  You can also get a can of sealed air to blast out any small particles and dust from the air vents and filter.

4.  Do not place anything on top of the projector or in front of the intake or exhaust vents. This will cause the projector lamp to overheat and fail. Refer to your manual for safe placement of the projector and the accessories.  The vents should be operating in an unrestricted environment that has strong air circulation.

5.  If the projector is built into a compartment, wall, ceiling, or shelf mount, the minimum distance requirement is usually at least 2 feet.  This allows enough space to dissipate any heat that will build up.  Refer to your owner’s manual for specific recommendations.

6.  When you replace the projector lamp make sure the new housing is seated completely and securely. Pureland Supply continually gets phone calls and inquiries from customers that think they have a defective lamp when in actuality they simply didn’t push the lamp in far enough.  Pay attention to the old lamp. Re-install and remove the old lamp a few times to get familiar with the how it fit into your projector. When you install the new lamp you can seat it firmly but without too much pressure.  Use the screws to tighten the lamp into its final position.

7.  Hot Projector Lamps are fragile. Do not move or shake the projector until the Projector Lamp has completely cooled. Shock and vibration applied to hot projector lamps may cause the lamp to break or shorten its effective lifespan.  It is recommended that after operation you let the lamp cool at least an hour before handling the projector or lamp.

8.  Do not unplug the projector until the Lamp has properly cooled. After the projector has been shut off, the fan will remain on for a period. This is required for proper cooling of the lamp.  If the lamp is not cooled properly it will cause the life of the lamp to be shortened drastically.  This is a critical point where many people unplug their projector during use in order to turn it off.  By doing this the lamp is extremely hot and has no air circulation resulting in damage or shortened life of the lamp.

9.  Do not turn the projector on and off frequently during presentations. Each time the projector is switched on, the inrush of power causes stress on the Projector Lamp as does the thermal cycles (heating cooling). Try to minimize your on/ off cycles by not frequently turning on and off. If you are not using the unit for less than 30minutes, use a screen saver or video mute option that some models offer.

10.   Wait until the fans stop running before attempting to turn a projector back on after use. Forcing the Projector Lamp to start before it is adequately cool will cause a thermal and electrical shock to the bulb causing the life to be shortened.

It is recommended that you have your projector serviced and maintained approximately every 2 years.

Preferably have the projector cleaned for dust buildup seasonally.

Insist on high quality projector lamps with the original manufacturer’s bulb inside (Made by Philips, Ushio, Phoenix, or Osram).  All lamps are available for sale at PurelandSupply

Call or Visit Pureland Supply at 1-800-664-6671 to get additional information on any type of Projector Lamp.


Pureland Supply
210 Gale Lane
Kennett Square PA  19348
Phone: 800-664-6671

Fax: 888-880-8874

Monday, November 27, 2017

Is My Projector Ready for the Holidays?

Unless you are me or involved in the home theater hobby I doubt this is a question you ask yourself. 

However, if you entertain regularly over the holidays it’s something worth considering.  Over the course of the year your projector is pulling a lot of air through it.  That air is used to cool the electronic components as well as the lamp.  Unless you are fortunate enough to live is a sterile environment you will get dust pulled inside with that cooling air.

Over time that dust builds up. That dust can start to prevent the air from cooling.  Once the dust builds up to the point to where it isn’t being cooled anymore and will start to act like insulation keeping the heat in.

Depending on your model, removing that dust can vary.  You always hear, “clean your projector”.  Sure, wipe the outside down and keep that machine looking nice. 

However, there is an entire world going on inside your projector.  Fans, ducts circuit boards Oh My! These all tend to gather dust regardless of how clean your house is.  Electronics in general tend to attract dust due to their nature.

There are many models that use filters.  Those filters vary from a complicated cartridge type that is consumable and requires replacement.  Then there are others that use a simple foam rubber filter on a carrier frame.  More recently the filters have been abandoned for under $1000 models. Instead opting for large open airways to channel the dust in and out rather than filtering it.

Short lamp life is the first symptom. More specifically a progressively shorter lamp life. Each lamp will run but maybe it fails after 500 hours. The next lamp fails after 200 hours.  These hour ratings are examples of course. You may see 1000 hours or more but no where near your original lamps life span.

This particular projector below uses a BL-FU310A which is on sale here. Once you clean your projector your BL-FU310A will run cool and bright.

Here are some examples of what your projector may look like inside if it has never been internally cleaned. Have it cleaned regularly to prevent failure during the holidays. Let us know if you have any question at 1-800-664-6671 or Sales@purelandsupply.com

Here is the side of the DLP Chip Heat-sink.

This is the main cooling Fan. Not moving much air.

Here is an overview of the entire projector’s electronics. That dust will cause heat problems.



This is the ballast. That powers the bulb. With this much dust it overheated and failed. Needed to be replaced, with a repair cost in the hundreds of dollars.


We do offer a Professional Cleaning Option. If this is something you would like to learn more about, please contact us with any questions. - PurelandSupply  1-800-664-6671 / Sales@PurelandSupply.com

Tuesday, November 14, 2017

Brands we sell continued...

Pureland Supply only sells the highest quality lamps. Our lamps are aftermarket housings engineered to fit the same as the OEM from the manufacturer. 

The brands we carry are:

Acer
Ask
Barco
BenQ
Boxlight
Canon
Christie
Dell
Digital Projection
Dukane
Eiki
Epson
Hewlett Packard
Hitachi
IBM
Infocus
JVC
Knoll
LG
Liesegang
Marantz
Mitsubishi
NEC
Optoma
Panasonic
Philips
Planar
Plus
Projection Design
Proxima
RCA
Runco
Samsung
Samsung
Sanyo
Sharp
Sim2
SmartBoard   
Sony
Toshiba
Ushio
Vidikron
Viewsonic
Vivitek

Contact us Today at www.PurelandSupply.com or give a call and speak to a real person instead of a recording. We are here 9-5 Eastern Standard time. You can also email us at Sales@PurelandSupply.com