Why Need to Install Door Mirrors?

Household anti-theft door is a relatively safe door that many families choose to install. Everyone can notice that there is a hole in the anti-theft door. It is a kind of hole designed for the convenience of indoor observation and outdoor. It is safety door viewer, which is also called a door mirror. For home safety, it is necessary to install a door viewer for the security door when decorating the house. Sometimes someone rings the doorbell outside, and if you open the door rashly, it may be someone who is unruly. If a small door viewer is installed at the door of your home, you can first check who is outside from the door mirror, and then decide whether to open the door or not, which is safer than opening the door directly. Today, we will share with you the relevant household anti-theft knowledge about installing door viewer on the anti-theft door.

 

The role of door viewer

 

Seen from the name, people can know that door viewer is a hole that can view outside of the door through it. Looking out from the room through the door mirror, you can clearly see all the scenes outside the door within the range of about 120 degrees, but from the door through the door mirror, you cannot see anything in the room. If you are living in a public house or private apartment, this mirror is installed on the door, which can play a certain role in preventing theft and safety of the family. It is the role of door viewers which can guard family safe.

 

The principle of door viewer

 

After we know its role, maybe some people are curious and want to know the principle of door viewer. Why people cannot see through it from the outside of door but they can see clearly from inside of the door? In fact, a good door viewer is mainly composed of a concave lens and a convex lens. The concave lens can shrink the portrait outside the door into the door mirror, which will form a three-dimensional virtual image. The convex lens has a magnifying effect, which allows residents to know the situation outside. The reason why the door mirror outside the door cannot see the portrait is that when the person outside the door uses the door mirror, the concave lens becomes the objective lens, and its focal length is very short, and the person outside the door cannot see clearly through the eyepiece. This principle enables residents to observe and judge the situation outside the door in the safest possible situation.

 

How to install the door mirror?

 

Before installing the door mirror, the specific diameter of the door viewer should be measured. If you install it, you need to use a hole opener to make a suitable hole on the door and install it. In fact, after buying a suitable door viewer, more people will choose to ask a professional team to install it. It is not only safer and more reliable, but also is convenient.