Home projectors are becoming more popular, but which specs should I pay attention to when purchasing? Let’s take Xiaomi “Mi Smart Projector 2” as an example.
What specs should you pay attention to in projector products that are appearing one after another?
Xiaomi, a comprehensive home appliance manufacturer, will release the home projector “Mi Smart Projector 2”. This product is Xiaomi’s first projector in Japan, and the suggested retail price is 89,800 yen (tax included).
Since the appearance of the popIn Aladdin projector with integrated ceiling light, it can be said that home projectors have become familiar to many people. Until a long time ago, home projectors were dominated by manufacturers that developed business projectors, but now manufacturers with various backgrounds are entering the market. One of them is Xiaomi.
Including crowdfunding, what should users focus on in home projectors that have a feeling of being crowded? Leaving aside too basic things such as the size of the main unit, let’s explain the points using the main specifications of “Mi Smart Projector 2” as an example.
“DLP method” is a simple solution that is easy to miniaturize
There is an upper limit to the resolution of the device
First of all, it should be noted that “Mi Smart Projector 2” is a “DLP method” projector. DLP is an abbreviation for “Digital Light Processing”, a video display technology by TI (Texas Instruments). After illuminating a collection of very small mirrors called a DMD (Digital Micromirror Device) with white light, the mirrors are operated individually at high speed to display images.
The advantage of the DLP method is that the structure is relatively simple, so it is easy to reduce the size and cost. In general, it is said that it is easy to obtain images with high contrast and sharpness. The disadvantage is that you may see “color breakup” noise that should not be displayed. This is also called “color breaking” and “rainbow noise”.
The liquid crystal method is often used in high-end home projectors. This is because the device resolution adopted by the DLP method for home use is up to 1920 × 1080. Among liquid crystal methods, when adopting a system called “reflection type”, the maximum resolution of the device is 4K. In addition to the above, the advantages of the liquid crystal system include the possibility of stable color display.
The resolution of “Mi Smart Projector 2” is also 1920 x 1080. It seems to be down-converted and processed when 4K signal is input.
However, there is also a model that realizes 4K display on the screen with a time division display method called “pixel shift” even in the DLP method. If the notation of “device resolution” and “display resolution” are different, it is due to the use of such technology. In terms of whether you need 4K resolution from your device, you should consider the size of the projection screen and the resolution of the main content you play.
“LED light” characterized by long life can be displayed for a long time like TV
One of the most important points in the fundamental system of a projector is the light source. This also affects the light output (brightness of the image) expressed in “lumens (lm)”. LED lights are a method that has been increasingly used in home projectors in recent years. Although it is difficult to ensure absolute brightness, it is characterized by long life and low power consumption.
High-pressure mercury lamps are often used as standard light sources. It can be said that it is easier to increase the brightness than LED, and it is also technically advanced. However, life is short.
By the way, the life of the light source often refers to the timing when the brightness is halved, and the life of the high-pressure mercury lamp is about 4000 hours (the high-pressure mercury lamp is often replaceable). In the case of LED, it may be 20,000 to 30,000 hours depending on the product.
In addition, some high-end products are equipped with laser light sources. Color purity is high, startup is quick, and the lifespan is equal to or longer than that of LEDs. However, the technology is still developing, and the product price tends to be expensive.
From the perspective of life, if you want to display images for a long time like a TV, you should choose a product with an LED or laser light source.
“500 lumens” is a modest number, but numbers aren’t everything
As explained in the light source (LED light) section, the “brightness” that a projector can output is expressed in lumens (lm), which is the total amount of light (luminous flux). In order to display high-contrast images, it’s basically better to be bright, but brightness is not directly linked to high image quality. It would be best if the number around 2000 lumens could be secured, but even if this is 1500 lumens, there should be no problem.
Looking at “Mi Smart Projector 2”, it says “Brightness: 500 ANSI lumens”. There is no doubt that the “luminance” mentioned here means brightness. Depending on the product, it may be written as optical output. Note that ANSI stands for American National Standards Institute, and indicates that the measurement value is based on a uniform standard.
500 lumens is a conservative number. The larger the projection screen, the less light per area, and the darker the image. When using a projector with brightness of several hundred lumens, it would be a good idea to consider a screen size of about 60 to 80 inches. Of course, don’t forget to make the room as dark as possible. This is also true for high-end projectors that can ensure a certain level of brightness.