Touch panel production
Touch screen is a kind of input device, used to sense the human body or object click, according to the communication interface, working method, lamination method, etc. are divided into many kinds
What is Full Lamination？
Full lamination is a process that uses OCA (Optically Clear Adhesive) to adhere the display module and the touch screen or protective cover together.
What is frame Lamination？
Use double-sided tape to fix the touch screen and the display around, there is an air layer between the display and the touch screen, which looks bad when the display is not working
Display vulnerable to interference
According to the working principle of touch screen can be divided into four types of touch screen, 1. resistive touch screen, 2. capacitive touch screen, 3. infrared touch screen, ultrasonic touch screen.
How the Touch panel works ？
Capacitive touch screen
Capacitive screen in principle, the human body as a capacitor element of an electrode, when there is a conductor close to the working surface of the laminated ITO coupled with a sufficient amount of capacitance between the capacitance, the current flow away is enough to cause the capacitive screen misoperation. We know that the capacitance value, although inversely proportional to the distance between the poles, is proportional to the relative area, and is also related to the insulation coefficient of the dielectric. Therefore, when a larger area of the palm of the hand or handheld conductor near the capacitive screen rather than touch can cause capacitive screen malfunction.
Capacitive technology touch screen is a four-layer composite glass screen, the inner surface of the glass screen and the interlayer is coated with a layer of ITO, the outermost layer is only 0.0015 mm thick protective layer of silica glass, interlayer ITO coating as a working surface, four corners lead to four electrodes, the inner layer of ITO for the shielding layer to ensure a good working environment. When the user touches the capacitive screen, due to the human body electric field, the user’s fingertips and the work surface to form a coupling capacitance, because the work surface is connected to the high-frequency signal, so the fingertips absorb a very small current away. This current is divided from the electrodes on the four corners of the touch screen, and theoretically flow through the four electrodes of the current and the finger to the four corners of the distance proportional to the controller through the four current proportional to the precise calculation, the location of the touch point.
Resistive Touch Panel
The main part of the resistive touch screen is a resistive film screen with the display surface is very compatible, which is a multi-layer composite film, a layer of glass or plexiglass as the base, the surface is coated with a transparent conductive layer called ITO, covered with a layer of external hardening treatment, smooth and scratch-resistant plastic layer, its inner surface is also coated with a conductive layer (ITO or nickel gold), between the two conductive layers have Many small (less than one thousandth of an inch) of transparent isolation points to separate them insulated. When the finger touches the screen, the two conductive layers in the touch point location there is a contact, the controller chastity to measure the connection and calculate the location of the X, Y axis, which is the most basic principle common to all resistive technology touch screen.
Xi=Lx×Vi/V (partial pressure principle) Yi=Ly×Vj/V
Resistive touch screen of the two layers of ITO working surface must be complete, in each working surface of the two edges of each coated with a silver glue, one end with 5V voltage, one end with 0V, it can form a uniform and continuous parallel voltage distribution in one direction of the working surface. After the chastity measurement to have touch, immediately A/D conversion to measure the analog voltage value of the contact point, according to the proportional formula will be able to calculate the location of the touch point in this direction.
Applications of our products
mobile phone capacitive touch screen
Nowadays, almost all smartphones use capacitive touch screens. Because capacitive touch screens can be fully fitted, there is no air gap in the middle, so the effect is very good and the operation of capacitive touch screens is sensitive.
Smart wearable product capacitive touch screen
Smart wearable products have been greatly developed, and the shipments of smart watches and smart bracelets are very large. Small-sized products have high requirements for touch accuracy and sensitivity, so capacitive touch screens are almost used.
Tablet PCs and Monitors Capacitive Touchscreens
Support 10-point touch, support size: 10.1″-65″
Touch Technology: Projected Capacitive (PCAP)
Response speed: <10ms
Touch Media: Finger, Glove, Touch Pen
Customization: Support customization Product certification: CE,FCC,RoHS
Operating System: Windows, Linux, Android, Mac
Industrial Resistive Touch Screen
Can support size: 2.7″-22″
Number of touch points: single point
Structure: ITO film + ITO glass
Interface: USB 2.0
Hardness: 3H Touch Life: 35 million times
Voltage: 2.5V to 5V DC Operating Temperature: -20°C- 70°C
Storage temperature: -30°C- 80°C
Product certification: CE,FCC,RoHS Applicable system Windows, Android, Linux
Industrial capacitive touch screen
Size 0.96~20 inch Structure G+F+F
Surface hardness greater than or equal to 6H
Transmittance greater than 83% IC model GT911
Structure G+FF (five points) Glass thickness
Working environment -20℃-70℃, 10%-90%RH Product model
Standard Compliant with ROHS standardApplicable system Windows, Android, Linux
Infrared touch screen above 33 inches
100% transmittance, available in bright places
Touch points: 16-20 points Response time: 10ms
Touch medium: finger, glove, touch pen Scanning frequency: ≥110Hz
Touch pressure: zero pressure
Light transmittance: 100% (without glass)
Light resistance: support
Product certification: CE, FCC, RoHS
Applicable operating system: Windows, Android, Linux, Mac
How many types of touch screens are available?
There are four common types of touch screens: from resistive, infrared type toward capacitive induction and surface acoustic wave type. Now the various types of touch screen is introduced as follows.
1.Surface acoustic wave type touch screen
Surface acoustic wave touch screen touch screen part is a reinforced glass plate, installed in front of the display screen. The upper left corner of the glass screen and the lower right corner of each fixed vertical and horizontal direction of the ultrasonic transmitter transducer, the upper right corner is fixed with two corresponding ultrasonic receiving transducer. The four perimeter of the glass screen is engraved with 45 ° angle from sparse to dense interval of very precise reflection stripes. When working, the transmitting transducer to the controller through the touch screen cable to send the electrical signal into acoustic energy to the left surface, and then by the glass plate under a set of precision reflective stripes to reflect the acoustic energy into the upward uniform surface transmission, acoustic energy through the screen body surface, and then by the upper side of the reflective stripes gathered into the right line propagation to the X-axis receiving transducer, receiving transducer will return to the surface acoustic energy into an electrical signal. When the finger or other objects that can absorb or block the acoustic energy touch the screen, the X-axis through the finger part upward acoustic energy is partially absorbed, and then the controller calculates the position of the finger based on the corresponding data. In addition to the general touch screen can respond to the X, Y coordinates, surface acoustic wave touch screen also responds to the third axis Z-axis coordinates, that is, the user can sense the size of the touch pressure value.
2. Capacitive touch screen
Capacitive touch screen structure is mainly in the glass screen coated with a transparent thin film body layer, and then outside the conductor layer in a protective glass, double glass design can thoroughly protect the conductor layer and sensor. In addition, in the additional touch screen on all sides are plated with narrow electrodes, in the conductor body to form a low voltage AC electric field. When the user touches the screen, due to the human body electric field, a coupling capacitance will be formed between the finger and the conductor layer, the current from the four electrodes will flow to the contact, and the strength of the finger and electrode distance is proportional to the controller located behind the touch screen will calculate the proportion and strength of the current, accurately calculate the location of the touch point. The double glass of capacitive touch screen can not only protect the conductor and sensor, but also effectively prevent the external environmental factors from affecting the touch screen, even if the screen is stained with dirt, dust or oil, the capacitive touch screen can still accurately calculate the touch position; in addition, the capacitive screen can be completely bonded to the display, and is not easily damaged and broken; capacitive touch can use the bonding pad bonding method, with waterproof function, very suitable for harsh environment applications.
3. Resistive touch screen
Resistive touch screen body part is a multi-layer composite film with the display surface is very compatible, by a layer of glass or plexiglass as the base, the surface is coated with a transparent conductive layer, covered with a layer of external hardening treatment, smooth and scratch-resistant plastic layer, its inner surface is also coated with a transparent conductive layer, between the two conductive layers are many tiny (less than one thousandth of an inch) transparent isolation points to They are separated from the insulation. When the finger touches the screen, the usual mutual insulation of the two conductive layers in the location of the touch point has a contact, because one of the conductive layer on the Y-axis direction of the 5V uniform voltage field, so that the voltage of the detection layer from zero to non-zero, the controller detects this connection, the A/D conversion, and the voltage value obtained compared with 5V can be the Y-axis coordinates of the touch point, the same reason that the X-axis coordinates, which is the most basic principle common to all resistive technology touch screen. Resistive touch screen is the key to material technology.
4. Infrared touch screen
Infrared touch screen installation is simple, only for the device plus the light point distance frame, no need to add a coating on the surface of the screen or connected to the controller. Light point distance frame on all sides of the arrangement of infrared transmitter and receiver tube, the screen surface to form an infrared network. When the user touches the screen with his finger at a certain point, the horizontal and vertical infrared rays passing through that location will be blocked and the computer can instantly calculate the location of the touch point.