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DIY projector: tips for beginners, calculation of parameters and implementation features at home (instruction + video)
Almost everyone dreams of having a big screen at home on which they can watch films at any time. But, unfortunately, not everyone can afford to buy a projector or TV, and that's when people start thinking about how to make a projector with their own hands.
Brief content of the article:
Before wondering how to make a projector at home, you need to familiarize yourself with the elements present in a store projector. Naturally, few people will be able to create such equipment as in stores, since here it is necessary to purchase several high-precision optical elements:
It is these elements that are responsible for how evenly the light is distributed on the screen.
The source of the picture in such devices is a matrix operating on liquid crystals, the work of which is carried out in transmission.
In this case, each pixel on the screen is displayed in an enlarged size. That is why you need to control so that the original picture is as clear as possible.
The projection lamp is responsible for the maximum screen size. This is all that is initially important to know for making a projector with your own hands.
In this case, the only thing needed to make the projector is a cardboard box and a magnifying glass. These items are inexpensive and can be bought at any household store. If possible, it is recommended to use a Fresnel lens instead of a magnifying glass.
Next, you need to place the lens in front of the phone (it acts as a source of the picture), which is preset to the highest possible brightness. After that, both elements are attached to the box and the projector can be considered finished. The picture is transferred to the screen (a sheet fixed to the wall can act as a screen).
This method of making a projector is ideal for children or teenagers who are just starting to understand the rules of optics, since the final picture will be of rather poor quality.
To manufacture the described device in this way, you will need a laptop, a cardboard box, a Fresnel lens made of hard plastic and tape.
The box must be selected so that its length is about 50 centimeters, while the area of the end part of the box must be larger than the size of the laptop screen.
The lens is allowed to be selected in various sizes, but the ideal option would be a size of 20 by 25 centimeters. Lenses of this size are used for reading books. The price of one lens ranges from $ 7 to $ 8.
Having prepared all these components for creating a projector, you need to follow the following step-by-step instructions:
A rectangle-shaped recess is cut out on the front wall of the box; its dimensions should be less than the dimensions of the lens. For accuracy, you need to attach the lens to a cardboard box as a sample, circle it, and then indent one centimeter inward on each side and draw a smaller rectangle. The drawn rectangle is cut out.
Using tape, attach the lens to the inside of the box's transverse edge. It is imperative to check the moment so that the lens is attached with the corrugated part.
You need to place the laptop with the screen down and put the keyboard on the top of the box. This position will make it possible to immediately achieve a direct and high quality image. But one must take into account the fact that the dimensions of the manufactured device will turn out to be quite impressive.
To make the projector look attractive, you need to separate the box from the laptop and paint it with a spray can in any color you like.
It should be taken into account that the Fresnel lens contributes to a slight distortion of the picture: its edges will be slightly blurred, and the center is focused. In this situation, in order to increase the clarity and brightness, it is necessary to maximize the brightness of the laptop and darken the room as much as possible.
But it is also worth noting that the brightness of the image also depends on the distance between the manufactured equipment and the screen. The closer the equipment is to the screen, the better the picture quality.
Another homemade projector idea is to use a flashlight or lamp in combination with a reading magnifying glass, preferably not very convex.
Initially, you need to create a screen for viewing the image, for this you need to hang a sheet on the wall, after which, at a distance of 2-3 meters from the screen, a chair is placed. A lighting fixture is placed on the chair. Slides should be placed in front of the light source; for this it is recommended to make a special stand, or you can simply hold the slides with your hand.
To enlarge the picture you need to use a magnifying glass. As a result, the slides must be positioned between the magnifying glass and the flashlight. The size and clarity of the image, as in the previous version, are regulated by changing the distance between the homemade equipment and the screen.
This type of projector is ideal for having fun with your kids.
Below you can find photos of various homemade projectors.
VIDEO Watching movies at home on the big screen is a very common desire. But its implementation is noticeably expensive for most dreamers. Otherwise, they would just buy either a projector or a TV. But for those who understand the device of electrical appliances, it is quite within their power to make a projection device for a home theater on their own. This will be discussed further.
First, let's take a look at the diagram of the correct projector. Obviously, not everyone can make such a device. If only because it will require a few precise and high-quality factory-made optical parts:
The uniformity of light distribution on the screen will depend on them. Light must enter the lens at the correct angle. If you do not know the optical characteristics of the lens and lenses, all distances can be determined empirically.
The source of the image in the projection device is a liquid crystal matrix. They work in the light. Moreover, each pixel on the screen is projected with an increase in size. Therefore, the original image should be as clear as possible. The more pixels the better.The so-called FULL HD is 1920 × 1080 pixels. The brightness of the projection lamp will determine the maximum screen size on which you can watch movies with acceptable brightness and contrast.
If the reader owns a smartphone or tablet with a bright screen and a resolution close to FULL HD, and also dreams of watching movies on a big screen, he can try to make a simple device out of the box, a lens and his gadget. The box-case should be larger in any cross-section than the gadget, and the diameter of the lens should be commensurate with the size of its screen. But the distance to the screen will depend on its focal length. The idea is simple:
a hole for the lens is cut in the box;
a gadget is placed inside, which can be brought closer or further away from the lens.
The gadget is installed in a holder, which is convenient to move around in the box. For the mandrel, another smaller box may be a perfectly suitable blank. The reflection of light from the walls of the boxes should be minimal. To do this, it is best to glue the surfaces over with black velvet applique paper. Or paint with black matte paint. You can use thick black shoe polish instead of paint. It is best to place rails between the sides of the boxes, especially when using velvet paper. They will protect the painted surfaces from rubbing.
That's the whole projector. We look at its details in the images below.
It is difficult to imagine modern methods of presentation and teaching without modern presentation equipment. Multimedia projectors, overhead projectors, slide projectors are not cheap equipment and periodically require repair and maintenance.
Projection equipment, projectors are rather complex devices for projecting a “live” picture onto a screen. Many of us still remember overhead projectors - devices that made it possible to project an image from a photographic film onto a screen - to view filmstrips. The overhead projector consisted of a lamp, a transformer feeding it, and a primitive optical unit. Modern projectors are much more complex.
First - the source of the picture ... The projector allows you to project a digital or analog video signal received from any compatible source - from a computer set-top box, DVD-player, set-top box digital broadcast and many other devices. Some modern models of projectors are equipped with memory card readers and USB storage devices for the convenience of instant viewing of photos and videos from digital camera memory cards.Secondly - the sound ... Most projectors are equipped with monaural or stereo speakers. Most likely, they will not be enough for comfortable viewing of full-length films, but they will still be useful in a mobile office presentation, or for watching a private video, where the sound quality is not so important, and there may not be a separate sound system.Thirdly - brightness ... It is no longer necessary to curtain the windows and turn off the lights in the room as it was before. The brightness of most modern projectors is sufficient to comfortably perceive the picture without reducing the level of illumination in the room.Thus, a modern projector is not just presentation equipment, but a full-fledged multimedia device that is not inferior in its capabilities to a TV, and in some parameters is superior to it.
What are the most common defects in video projectors? What are the disadvantages of surrendering projectors for repair ?
Projector repair with a defect does not "light up the lamp" (indication "Lamp")
Projector repair with a “burnt-out pixels on the screen” defectvideo projector repair . Repair of such a projector comes down to replacing the optical unit.
Projector repair with the defect "spontaneously turns off a few minutes after the start of work"Projector repair with the problem of overheating - this is a set of measures for replacing thermally conductive elements, or finding and replacing a faulty microcircuit. Projector repair with the Iris Unit problem, it assumes the replacement of faulty curtains.
Projector repair - not an easy task. Trust it only to specialists. Remember: unskilled intervention increases the cost of repairs several times or even makes production projector repair unprofitable!
Repair of projectors requires not only high qualifications from the master, but also the appropriate conditions and devices, therefore repair of projectors we carry out only in the service center.
If you have already encountered the need repair of projectors Sharp, Epson, HP, NEC, Sanyo, Sony, Toshiba, Acer, Panasonic, Hitachi, LG, Benq, Mitsubishi, Fujitsu, JVC, ViewSonic, InFocus and other manufacturers, our engineers will produce projector repair with high quality, with a guarantee, in the shortest possible time and at reasonable prices .. The specialists of our company have many years of experience in the field of repairing home theaters and office projection equipment, they will be able to provide you with qualified assistance in any breakdown, whether it is repairing power boards, control boards, bus converter, control panels, replacement of the lamp unit, lamps, etc.
Factors determining the timing of projector repair :
the degree of complexity of the work performed (it is natural that the complete replacement of individual components and projector blocks is a faster and less laborious process, however, for the client it is most materially costly than repair of projection equipment at the component level)availability of spare parts to be replaced (in some cases, when it is impossible to avoid replacement of components, the main factor determining the period projector repair , is the availability of the necessary spare parts in the warehouse of the service center).
DLP projector Acer DNX0811 started flashing 15 minutes after being turned on ... We decided to hand over to the supplier under warranty, but received from the service center refusal to repair with the wording - dust interferes with the repair and normal operation of the device. At the same time, they wanted as much as 3000 rubles for cleaning from dust. It was decided to clean it ourselves. To do this, we need a choice - either a pneumatic cleaner, or an air compressor and, in fact, itself DLP projector Acer DNX0811 .
First, lift the lid and unscrew the two screws holding the projector lamp. We take out the lamp up.
We see sufficient dust layer on the fan blades and inside on the walls.
And for nothing that the projector was hanging from the ceiling. Apparently the dust rises remarkably.
unscrew another bolt top cover.
Turn the projector over and unscrew five self-tapping screws at the bottom of the projector.
Lift the top cover - be careful, it is connected to the signal board by a loop.
Carefully disconnect the loop from the board.
Under the cover we see a signal board, covered with a shielding plate. Unscrew the screws holding the screen and the projector board.
Disconnecting the cables from the signal board of the projector and remove it.
Below we see the boards of the power supply unit and the lamp ignition unit. To take off projector lamp inverter, unscrew the screws. If you look at the optics unit, you can see a plug on two screws in the form of a heat dissipating heat sink.
Projector Lamp Inverter Unit shown in the photo.
To remove the projector's power supply, you must also unscrew the screws and remove the cables.
Pay attention to the appearance thermistor, which is attached to the wall behind which is the hot lamp. It protects the lamp from overheating. Logically, it is he who extinguishes the projector backlight when it reaches critical temperature lamp. In turn, the lamp may overheat due to the presence of dust on the reflective walls inside it and on the inner walls of the projector.
We know the dust lays down thin heat-insulating layer ... It is enough to worsen the heat exchange by 10 percent and such problems may begin. Of course, this statement is not true for all projectors, but it turns out that the Acer DNX0811 DLP projector has small margin for exceeding the temperature regime.
Based on this, there is only one conclusion - dust thoroughly ... Let's start by cleaning the optics.
Then we blow inner walls of the lamp.
This is how they look projector internals after cleaning.
By the way, for the purge I used compressor MetaboClassicAir 255 and a blow gun. Generally speaking, compressor is good , but a noisy infection and vibrations on the floor gives a lot. In general, it is better not to install next to working hard drives.
The projector is calibrated immediately after purchase and installation. This is due to the fact that standard picture settings are usually far from ideal. The calibrated device allows you to view videos, photos, pictures in better than the original quality. The purpose of the whole process is to achieve visual parameters, the most close to reality ... Commissioning will require special instruments and suitable software. To avoid unnecessary costs, the work can be done using a computer yourself.
Projectors – these are special devices designed to project the transmitted image onto the screen. They differ from each other in the principle of operation and in the quality of the rendered picture. Manufacturers release models that have various standard and custom settings for the displayed picture. To achieve the maximum high-quality visual effects , you will need to calibrate the device before using it.
Fine tuning can be compared to laboratory work that requires the use of a range of research tools, such as:
spectrophotometer;
colorimeter;
reference images;
free (paid) software set.
It is recommended to adjust the parameters according to the full program in the following sequence:
sharpness (characteristic of the clarity of the outline of the displayed object);
purity (is an indicator of the absence of interference and other defects in frames);
color accuracy;
contrast level;
the amount of resolution.
Color is adjusted by manipulating the following sequence of indicators:
white and black level;
gray range;
color (shades);
Color palette.
To complete a full-scale projector setup with your own hands, you will need to stock up on specialized knowledge and purchase expensive equipment. It is better to use paid programs with ample opportunities. But for a one-time adjustment at home, it is quite enough to use computer with built-in instrumentation .
Adjustment works are designed to ensure that the color characteristics are close to the reference indicators.The latter are taken from special tables , or the graphs contained in the software base or used setting equipment. According to the principle of adjusting the parameters, there are 2 approaches to the calibration process. These are discussed in the following table.
In practice, tuning by specialists is carried out using both principles and additional equipment.
At home The easiest way to tune the projector for the best picture quality is by two methods:
setting the parameter values manually on the projector and comparing the result with the selected standard;
by connecting to a computer and using the standard calibration program in the display settings.
If photos (slides, presentations) are often viewed in the family circle, then to improve the picture, you can use the tools built into the Power Point program on your computer.
This method allows you to manually adjust the saturation, brightness, clarity, contrast, color gamut parameters. A test image from a DVD player or computer is used.
Work should begin with creating conditions that are most consistent with the illumination of ordinary movie viewing (photo). It is better to turn off artificial light sources and reduce natural light by closing the blinds (curtains). Requires a custom mode on the projector.
In addition to lighting, the result is influenced by:
distance from the screen;
the number of spectators;
individual preferences;
screen quality.
VIDEO
The process for determining the preferred parameters will proceed as follows:
selected test picture : the best option is a black and white photo containing texture fragments and small details;
the smallest values of the adjustable parameters are set;
gradually, changing them upwards, check the standard with the resulting image;
each characteristic is adjusted to achieve a level that creates the most favorable visual impression;
upon completion - save the obtained result.
The following signs can serve as a criterion for the correctness of the selected settings:
when reproducing the rest of the reference fragments, a high-quality image is obtained;
eyes do not get tired while watching;
the broadcast frames are not dazzling.
The result obtained is the personal visual preference of the calibrating individual. The work is done by eye.
The projector can both replace a computer monitor and be used together with it as a second screen. By connecting the device to a personal computer, you can calibrate it using a mouse and a conventional keyboard.
Quite often, to connect 2 devices, you need a VGA-DVI cable and various adapters (their type depends on the connectors available on the model used).
After docking the projector with the computer through the appropriate ports, the latter should display a message with the New Hardware Wizard. Next you need install drivers included with the device or downloaded from the Internet.
The interaction of a computer with a projector and a monitor is formed as follows:
go through "Start" to the control panel menu;
there in the subsection "Design" find the item "Screen";
then go into its parameters;
when the computer has detected an additional device, then 2 "desktops" and a list indicating the presence of multiple screens are displayed;
you can select the main display and then switch, either the "Duplicate" option or screen extensions;
the menu item "Orientation" allows you to immediately designate the way the incoming information is displayed by the projector.
When dubbing, the output from the output devices connected to the PC will be the same. And when it expands, it complements each other.
VIDEO
If, after connecting the device, an error popped up on it indicating the impossibility of recognizing the signal, then you will need change resolution on pc ... The appropriate value for the projector used is taken from the instruction manual for the projector.
Calibration is done as follows:
open the menu of the "Screen" item from the control panel;
then select the section "Calibration";
the menu that appears is transferred to the screen of the device being configured;
follow the step-by-step pop-up instructions;
as a result, a suitable gamut is selected from the presented options, click "Next";
similar actions are performed when adjusting brightness and contrast.
The use of a PC allows all commissioning to be carried out quickly and automatically. The result of all the manipulations will be the achievement of the most acceptable display of the video material.
Built-in Power Point tools allow calibrate presentations from photos and pictures ... The procedure is as follows:
in the "Slide Show" tab, find the playback item on the projector;
with the help of the menu of the section "Resolution" change the quality of frames.
The result achieved will be a reflection of personal taste. It is recommended that the calibration be performed jointly to ensure that all family members are concerned.
Calibration is preferably carried out every six months. This will make it possible to correct software failures in time, to maintain the quality of the output video at a high level.
VIDEO
Video (click to play).
Projector calibration is the only tool that can bring the visible image closer to reality, and the film to what the director wanted to show. High level of detail, play of colors will bring an indescribable pleasure while watching. The use of equipment (if necessary, buy it additionally) is not quite advisable for setting up only your home device. In the process, you can also do without the involvement of specialists. Do-it-yourself work will help you to do the usual computer and the use of free programs.
