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Resistive touch screen working principle

The working principle of the resistive touch screen is mainly to realize the operation and control of the screen content through the principle of pressure sensing. The screen body of this touch screen is very close to the display surface.

Working principle of resistance screen

The working principle of the resistance touch screen is mainly to realize the operation and control of the screen content through the principle of pressure induction. The screen body of this touch screen is a multi-layer composite film that is very matched with the surface of the display. The first layer is glass or organic Glass bottom layer, the second layer is an interlayer, the third layer is a multi-resin surface layer, and the surface is also coated with a transparent conductive layer, it is covered with a smooth scratch-resistant plastic layer with a hardened outer surface. The conductive layer on the surface of the multi-component grease layer and the glass layer sensor are separated by many tiny spacers. The current passes through the surface layer. When the surface layer is pressed lightly, it touches the bottom layer. The controller simultaneously reads the commensurate current from the four corners and calculates the distance of the finger position. The touch screen uses two highly transparent conductive layers to form a touch screen, and the distance between the two layers is only 2.5 microns. When a finger touches the screen, the two conductive layers normally insulated from each other have a contact at the position of the touch point. Because one of the conductive layers is connected to a 5V uniform voltage field in the Y-axis direction, the voltage of the detection layer changes from zero to non-zero. After detecting this connection, the controller performs A/D conversion and compares the obtained voltage value with 5V to obtain the Y-axis coordinate of the touch point, in the same way, the coordinates of the X axis are obtained, which is the most basic principle common to all resistive technology touch screens.

Introduction of specific types of membrane switches

A flexible membrane switch is a typical form of membrane switch. This type of membrane switch is called flexible because the membrane switch mask layer, isolation layer, circuit layer are all composed of a variety of different properties of flexible film. The circuit layer of flexible membrane switch adopts polyester film (PET) with good electrical performance as the carrier of switch circuit pattern. This layer is also equipped with feel shrapnel and upper and lower circuits. Due to the influence of the properties of the polyester film, the membrane switch has good insulation, heat resistance, bending resistance and high resilience. The graphics of the switch circuit, including the on-line of the switch and its outgoing lines, are printed with low-resistance, low-temperature curing conductive paint. Therefore, the composition of the entire membrane switch has a certain degree of flexibility, which is not only suitable for use on a flat body, but also can be matched with a curved body. The lead wire of the flexible membrane switch is integrated with the switch body itself. When making the group switch online, it is collected at a certain place of the membrane and extends outward according to the position specified by the design and the standard line distance to be connected with the rear circuit of the whole machine as a soft, bendable and sealed lead wire.

Structure of membrane switch

The panel layer is generally made of fine patterns and characters on colorless light-transmitting sheets such as PET and PC less than 0.25MM. Because the main function of the panel layer is to play the role of identification and keys, the selected materials must have the characteristics of high transparency, high ink adhesion, high elasticity, high toughness, etc.

Membrane Switch Method Steps

Method steps 1. Clean the surface to be attached to the membrane switch (the surface to be attached is required to be flat, free of rust, oil and dust); 2. Compare the size (put the membrane switch in the place to be pasted to compare whether the size position is right); [4] 3. Peel the centrifugal paper at the bottom of the membrane switch about 10mm from the side; 4. Then put the membrane switch in the corresponding position and stick it to a part, then slowly tear off the remaining centrifugal paper (in the case of an angle of no more than 15 degrees), and then stick it to the corresponding position in turn. [4] 5. In the process of pasting, if the membrane switch of the reverse centrifugal paper needs to be placed first, the reverse side should be placed upward to prevent sticking to other objects and affect pasting; 6. Precautions: Paste cannot be repeated and must be completed at one time. The tearing angle cannot exceed 15 degrees; When trying to press the hand feeling, be sure to lay it flat on the desktop and press it again. You cannot hold it in your hand and press it, otherwise it will affect the service life of the membrane switch.

What are the common types of membrane switches?

Membrane switches are closely related to our lives, such as: microwave ovens, rice cookers, etc., the above are the use of membrane switches, then, what are the common classification of membrane switches. 1. Divided into panel and discrete parts and keycap and keyboard according to the combination method. What are the common types of membrane switches? 2. According to the circuit substrate, it is divided into flexible board and rigid board. 3. According to the panel shape, it is divided into plane type or three-dimensional type. 4. According to the operation feeling, it is divided into non-inductive type and inductive type. 5, according to the special purpose is divided into transparent and refers to the touch screen type.