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What causes your smartphone to get hot?Professionals explain how to cool it based on the results of thermography | Time & Space by KDDI

This summer's hot day is continuing, but I have never experienced "smartphones become hot if I was shooting videos under the scorching sun" or "If you play a game for a long time, your smartphone will be hot and the screen will be stuck."I wonder.As the temperature rises, smartphones tend to get hot, and long -term video shooting, video viewing, games, etc. tend to have a lot of load on smartphones and tend to get hot.

So what kind of operation is the smartphone tend to get hot?I performed an operation that tends to get hot on the smartphone and measured the temperature using thermography.Let's convey the mechanism that tends to get hot, how to deal with it, and how to cool the smartphone.

First, let's briefly explain the case where the smartphone gets hot.In the first place, the smartphone itself becomes hot and difficult to cool down as the environmental temperature increases, such as under the hot weather in summer.In addition, the CPU, camera, and communication control unit inside the smartphone are also fever.If the load on the CPU, camera, and communication control departments, such as long -term games, video shooting, and video viewing, the smartphone tends to be hot.In addition, since the charging treatment also generates heat, "while charging", which operates the smartphone while charging, becomes hotter of the smartphone.

If the internal temperature rises in a personal computer, the heat can be lowered by fans for exhaust heat, but there is no small smartphone.There is only a method of dissipating heat from the smartphone itself and lowering the temperature, so if the heat generated exceeds the amount of heat dissipation, the smartphone becomes hot.

Nevertheless, there are some temperature sensors in the smartphone body, reducing the processing speed of the CPU, reducing the brightness of the screen, and stopping charging so that it does not exceed a certain temperature., The "safety function" that stops the camera function is operated.

The operation of the smartphone's safety function appears symptoms such as "the display is muddy", "the charging cannot be charged (the charging stops)", and the "camera does not start".They tend to think that the smartphone has broken down, but in fact it is an intentional operation to "suppress the temperature rise that leads to low -temperature burns."

In fact, I experimented with the editorial department to see what kind of operation increases the temperature of the smartphone.Click here for an overview.

① Four smartphones with the same specifications and the same battery level.(2) The air conditioner temperature setting is 26 ° C, indoors of "Game", "Video Shooting (4K)", "Video Watch (YouTube)" and "Charging (Charging & Surfing)" for 10 minutes.③ Check the smartphone temperature after 10 minutes with the thermography.

If you look at the temperature of the smartphone before the experiment in the thermography, 27.3 ° C.

Then, the experiment start!

The four smartphones performed the following operation for 10 minutes.

● Game 3D Space plays FPS (First Person Shooting) Game ● Video Shooting (4K) Fix it to a tripod and shoot 4K videos ● Watching video (YouTube) Refrush YouTube while charging while charging while charing while charing while charing.

スマホが熱くなる原因は?サーモグラフィの結果を元に冷やし方などプロが解説|TIME&SPACE by KDDI

About 5 minutes have passed since the operation started.Among the four units, the temperature of "video shooting" rises rapidly 43.It reached 5 ° C.

At the time of 5 minutes, the next temperature was 37 in the "game"..2 ℃.Next is "charging while charging" 36.9 ℃.Next is "Video Watch" 33.5 ° C.

After 10 minutes, the experiment of which smartphone will get hot will end.Click here for the result.

1st place video shooting (4K) 46.Charging (charging & online surfing) 37 in the second place in 5 ° C.7 ℃ 3rd place game 37.4 ℃ 4th place Video Watch (YouTube) 34.1 ℃ * The result of this experiment is a reference value

In the experiment in this editorial department, the temperature of the smartphone was the highest in "Video Shooting" 46..5 ℃.The second place is "charging while charging" 37.7 ° C, 37 is 37 in "game".A small difference from 4 ° C.4th place is "Video Watch" 34.The result was 1 ° C.

We asked Ichiro Yamanishi, a smartphone quality control expert in KDDI, about the experimental results.

KDDI 品質管理部 山西一郎

――What is the reason why the video shooting became the hottest?

"Generally, the camera unit mounted on a smartphone is a part that is easy to hold heat. In the experimental thermography, the left side of the smartphone laid sideways is hot, but there is a built -in camera unit.In the case of the camera, the camera is constantly running, so it will be easier to generate fever. "


――Following the video shooting, the charging is 37.7 ° C, the game is 37.4 ° C, 34 video viewing.It became hot in the order of 1 ° C.

"The game that often uses CPU is a game. For example, the game that uses 3D seems to have a high CPU load, probably because it always creates new graphics. In addition, games with communication functions also use communication functions.Because it is done, it costs more.

I think that the net surfing while charging is a fever due to charging and a fever due to communication function.Although it is the 4th place video viewing, the communication function is working, but I think the load on the CPU is relatively light.

Also, the effects of the outside temperature cannot be overlooked.In an environment under the scorching sun, the smartphone is heated and heat dissipation is disadvantageous.If you use a smartphone in the scorching sun, such as leisure and sports, avoid the place where direct sunlight is exposed, stop using it and rest, so that it does not use it for a long time. "

Actually, when a smartphone was placed outdoors with a outside temperature of 31 ° C, it was only 1 minute exceeded 40 ° C, 45 ° C in 5 minutes, and 48 ° C after 10 minutes (!).It turns out that smartphones tend to get hot outdoors in summer.

――How is it better to cool a hot smartphone?

"Smartphones will cool down naturally when the fever is gone, so stop using the applications you are using first and rest your smartphone. Turn off the power. If you are inside, you can expect to stop charging. Natural cooling is the most preferable, so it is not recommended to put it in a refrigerator or use a cooling agent. I think."

――Why isn't forced cooling recommended?

"If the temperature of the smartphone drops rapidly, the inside will be condensed, the water will adhere to the precision equipment, causing corrosion and short circuit, and it will lead to a failure." Cool with ice water because it is a waterproof smartphone. "The appropriate cooling method of a smartphone is to cool it down naturally. Sudden decrease in temperature is strictly prohibited. "

After the experiment, I finished the app, rested my smartphone and measured the temperature."Video shooting" 35 after 10 minutes.2 ° C, 33 "charging".9 ° C, "game" 32.8 ° C, "Video Watching" 33.Even if it did not hit the wind at 6 ° C, the smartphone was cooled properly just by turning it on the standby screen.

In summer, smartphones tend to be hot, and long -term video shooting and games have a heavy load on smartphones.I want you to temporarily stop using your smartphone before the body gets hot and rest your smartphone in a cool place.