Now, the ever-changing mobile phone, but the function is much the same. Bring the iPhone since jobs, mobile phones can not see the keyboard, looks more like a small monitor ... ... However, the screen is bigger, more episodes or something bad, you can DIY a small box, turn the mobile phone into a portable projector.
This project only according to the principle of making, the actual effect is for reference only.
Mobile projection principle
Regardless of is real of projector, also is today to do of this phone projection box, actually principle are is simple, that is "convex lens imaging", this in middle school physical in the on introduced had has: Dang objects put in convex lens focus zhiwai, in convex lens another side into inverted of blending, also has a formula: real (from) far like (from) near small, real near like great. Projector is by adjusting the distance between lens and projection source, to change the size of the projected image.
Principle of the projector
When it comes to projecting sources, projectors currently has a variety of types, common to both LCD and DLP. DLP (Digital Light Processing, digital light processing) technology is Texas instrument company of patent, its core is a digital micro-mirror chip, this is a arranged with countless "small mirror" of chip, each a pixel corresponds to with a "small mirror", it relies on of not change incident light of polarization State or itself glow State, but adjustment specific location micro-reflection mirror of reflection angle--if need some pixel of location glow, on drive small mirror, let light reflection to lens So images appear on the screen. Clearly, the way DLP works too high end, not suitable for DIY production. LCD projector technology is much easier, especially now that many DIYer often used the principle of single-chip LCD projector: using the LCD screen as translucent screen, images directly through the lens is projected onto the screen.
So, I use a mobile phone as the projection source, so don't need to consider issues such as light, heat, the only regret is, the brightness of the screen is not too high, after lens refraction and scattering, the brightness of the projected limited, can only be used in darker environments.
Summary projection box internal structure
Design and material selection
Based on the above principles, we can put the "projector" very simplified: projected as mobile sources, using a single convex lens or a Fresnel lens of the camera, a correction like mirrors, combined with a compact and lightweight box is OK.
Projection source--cell phones:
LED projector resolution is determined by the LED screen resolution, use mobile phones as a LED projector projection source, a large screen, high brightness, high resolution mobile phone is necessary. I used the OPPO Find 5 sponsored by the OPPO cell phones as LED projection sources, it has a 5-inch 1080p screen, 1920x1080 resolution, pixel density of 41ppi (Pixels per inch, number of pixels per inch), by refraction of the lens zoomed in, better reflects the advantages of fine quality. Because we want to make a projection light source projector, the source of all the light from the screen itself, OPPO Find 5 phone screens up to 480 lumens brightness, the drop shadow effect is good. In addition, the OPPO Find 5 occupied nearly the entire front screen of the phone, the border only 3.25 mm, so you can make the box as small as possible, reduce the scattering of light, very suitable as a mobile projection source.
Projection source: OPPO Find 5 mobile
Lens:
Greatly simplifies the structure, if using a regular convex lens, corners will appear dim and fuzzy phenomenon. This is because the refraction of light occurs only in the media interface, convex with a thick, light travels in straight lines in the glass part will make the ray attenuation. If you can remove the straight part, leaving only the bent surface, it can save a great deal of material at the same time achieving the same spotlight effect. Fresnel lens is to adopt this principle. Fresnel lens looks like a unlimited number of concentric lines (Fresnel zone) of glass, but it can achieve the effect of convex lenses, projection light source is directional, brought together project to keep a consistent brightness throughout the image, so I used as the projector lens feinier lens. Vera Bradley iPhone 6 cases
Fresnel lens vs through convex lens iPhone 6 cases Vera Bradley
Source: Shell mesh
Reflector:
Convex lens image is inverted real image, although now the phone screen with 180-degree rotating function, but cannot control the flip, so to see a normal text and images, use a small mirror to solve it.
Box:
In order to minimize phone projection, according to the dimensions of the phone and the Fresnel lens focal lengths, calculate the best size. Box, stiff cardboard, paper boxes, PVC plastic and all, principle is to minimize light tight, inner wall are also not reflective.
3D projection box structure diagram
https://www.youtube.com/watch?v=y__kWv23Hlo
Card materials
Fresnel lenses, mirrors, light wood, non-woven fabric
Shell material is 3mm non-woven, lined with a cell phone/mirror mounting bracket, 3mm balsa sheet production.
Production process
Based on the previously calculated distance, designed a box size, make good parts of the box with a cardboard template. Author tests found that distance between reflector and Fresnel lens at about 7CM, to throw about 20 at a distance of 1.5-inch clear images.
Implementation prepared paper template first, draw the outline of the various parts in the non-woven, cut out with scissors.
Fresnel lens dug holes to fix the lens (side towards the inside of the lines).
Between the two sides of the box and the box using the stitching process, resorted to killing machine--a sewing machine.
Source: Shell mesh
Balsa sheet to make a mirror frame, used to place the phone on the bottom.
Give feinier lens in front of a border, so as to underpin the box, fit right in.
Box shaped.
How to make it cover more beautiful? Metal buttons-the need to use a hammer to buttoned.
Solve the problem of lid, and cell phone/mirror bracket in the box and you are done!
See the final look!
Projection box ready, phone fixed bottom position how to control a mobile phone cell phone? You can use the Bluetooth mouse if your cell phone and operating systems support for Bluetooth transmission.
Room for improvement
First of all, is the material of the box, if it is possible, you can use sturdier materials, such as wood or glass materials, made with black shade cloth lining.
Now due to the fixed size of the box, the object distance is not adjustable, Fresnel lens in the front end if you can move back and forth, cast images can be resized and, of course, clear projection distance (distance) have to rely on your mobile.
Source: Shell mesh
No comments:
Post a Comment