CN106406588B - Touch display device - Google Patents

Abstract

The invention relates to a touch display device, which comprises a protective cover plate, a capacitive touch unit and a display module, wherein the capacitive touch unit is positioned on one side of the protective cover plate and used for acquiring position information of a touch object, the capacitive touch device also comprises a pressure touch unit positioned on one side of the display module, which is far away from the protective cover plate and used for acquiring pressure information of the touch object, and the pressure touch unit comprises a flexible circuit board and a plurality of force sensors arranged on the flexible circuit board. According to the invention, the force sensor is integrated on the back of the display module, and the force sensor is arranged on the flexible circuit board, so that the combination of position and pressure dual detection is realized, the structure is simple and compact, and the man-machine interaction experience handfeel can be improved.

Description

Touch display device

Technical Field

The present invention relates to the field of display technologies, and in particular, to a touch display device with a pressure sensing function.

Background

Currently, products such as mobile phones, tablet computers, televisions and the like with touch control functions are increasingly popular. The touch control function of the products is realized by arranging a touch screen.

Most of the current touch screens adopt capacitive touch screens, the capacitive touch screens work by utilizing current induction of a human body, namely, the touch operation can only be performed by touching an object made of a conductor material, and if a user carries a glove or performs the operation by using an object made of an insulating material, the touch operation cannot be realized.

Disclosure of Invention

Based on the above, the present invention aims to provide a touch screen that can realize an insulating material touch operation.

The utility model provides a touch display device, includes the protection apron to and be located the electric capacity touch unit and the display module assembly of protection apron one side, electric capacity touch unit is used for acquireing the positional information of touch object, still includes the pressure touch unit that is located the one side that the protection apron was kept away from to the display module assembly, pressure touch unit is used for acquireing the pressure information of touch object, pressure touch unit includes flexible circuit board and sets up a plurality of force sensors on the flexible circuit board.

According to the invention, the force sensor is integrated on the back of the display module, and the force sensor is arranged on the flexible circuit board, so that the combination of position and pressure dual detection is realized, the structure is simple and compact, and the man-machine interaction experience handfeel can be improved.

In one embodiment, the force sensor is a piezoelectric sensor and comprises a piezoelectric film and electrodes arranged on two sides of the piezoelectric film, electrode leads are arranged on the flexible circuit board, and the electrodes are bonded with the electrode leads through conductive adhesive.

In one embodiment, the force sensor is a piezoelectric sensor and comprises a piezoelectric film, electrodes and electrode leads correspondingly and electrically connected with the electrodes are arranged on the flexible circuit board, and the piezoelectric film is correspondingly bonded with the electrodes on the flexible circuit board through conductive adhesive.

In one embodiment, the force sensor is a strain type force sensor, and the strain type force sensor comprises a metal strain gauge or a semiconductor strain gauge, wherein the semiconductor strain gauge or the metal strain gauge is electrically connected with the flexible circuit board through conductive adhesive, and the semiconductor strain gauge or the metal strain gauge can deform under pressure so that the resistance can change.

In one embodiment, the force sensor is a resistive force sensor, and includes an organic composite film doped with conductive particles and electrodes disposed on a surface of the composite film, wherein when the composite film is pressed, the resistance between the electrodes of the composite film changes.

In one embodiment, the flexible circuit board is bar-shaped, frame-shaped or block-shaped.

In one embodiment, the display module comprises a visible area and a non-visible area located at the periphery of the visible area, and the force sensor is arranged in the non-visible area of the display module.

In one embodiment, the force sensor is located between the flexible circuit board and the display module.

In one embodiment, the pressure touch unit further includes an operation chip disposed on the flexible circuit board.

Drawings

Fig. 1 is a schematic diagram of a touch display device according to an embodiment of the invention.

Fig. 2 is a schematic top view of a pressure touch unit in the touch display device shown in fig. 1.

Fig. 3 is a schematic structural diagram of a touch display device according to another embodiment of the invention.

Fig. 4 is a schematic structural diagram of a touch display device according to another embodiment of the invention.

Fig. 5 and fig. 6 are schematic structural diagrams of a flexible circuit board in a pressure touch unit according to different embodiments of the present invention.

Detailed Description

As shown in fig. 1, the touch display device according to an embodiment of the present invention includes, in order from top to bottom, a protective cover 10, a capacitive touch unit 20, a display module 30, and a pressure touch unit 40.

The protective cover 110 may be a reinforced glass cover, a plastic cover, a polymethyl methacrylate (PMMA) cover, or the like.

The capacitive touch unit 20 includes a plurality of driving electrodes and sensing electrodes, and the two touch electrodes may be distributed on the same substrate, or may be distributed on two different substrates, that is, the capacitive touch unit 20 and the protective cover 10 may be formed into structures called GF, GFF, OGS, etc. The touch electrode is led out to one place through silver paste and is bound with the flexible printed circuit board of the capacitive touch unit 20 through Anisotropic Conductive Film (ACF), and the chip of the capacitive touch unit 20 can be positioned on the flexible printed circuit board or a main board of a touch display device (such as a mobile phone). The capacitive touch unit 20 may detect and obtain accurate position information of a plurality of touch objects by means of capacitive coupling.

The display module 30 is disposed on a side of the capacitive touch unit 20 away from the protective cover 10. It is understood that the display module 30 may be integrally provided with the capacitive touch unit 20 in some embodiments.

The pressure touch unit 40 is disposed at a side of the display module 30 away from the protective cover 10. The pressure touch unit 40 is configured to obtain pressure information of a touch object. The pressure touch unit 40 includes a flexible circuit board 41 and a plurality of force sensors disposed on the flexible circuit board 41.

As shown in fig. 1 and 2, the force sensor is a piezoelectric sensor, and includes a piezoelectric film 42 and electrodes 421 and 422 disposed on both sides of the piezoelectric film 42, electrode leads 411 and 412 are disposed on the flexible circuit board 41, and the electrodes 421 and 422 are bonded to the electrode leads 411 and 412 through conductive adhesive 60.

Fig. 3 is a schematic diagram of a touch display device according to another embodiment of the invention, where the force sensor is a piezoelectric sensor, and includes a piezoelectric film 42 and electrodes 421 and 422 disposed on two sides of the piezoelectric film 42. The flexible printed circuit board 41 comprises an upper substrate 413, a lower substrate 411 and an isolation layer 70, wherein an electrode lead (not shown) is provided on the lower surface of the upper substrate 413 and electrically connected to the electrode 421 of the piezoelectric film through the conductive paste 60, and an electrode lead is provided on the upper surface of the lower substrate 411 and electrically connected to the electrode 422 of the piezoelectric film through the conductive paste 60. The separator 70 serves to prevent short circuits of electrode leads on the surfaces of the upper and lower substrates 43 and 41. Meanwhile, in the non-piezoelectric film region in the flexible printed circuit board, electrode leads of the upper substrate 413 are guided to the surface of the lower substrate 411 by means of through holes so as to be electrically connected to external devices.

In another embodiment, as shown in fig. 4, the electrodes 421 and 422 may be directly formed on the upper substrate 413 and the lower substrate 411 of the flexible printed circuit board 41, respectively, and connected to the corresponding electrode leads. Opposite sides of the piezoelectric film 42 of the piezoelectric force sensor are respectively bonded with the electrode 421 on the upper substrate 413 and the electrode 422 on the lower substrate 411 through the conductive adhesive 60.

When the piezoelectric sensor is stressed, induced charges are generated on the upper side and the lower side of the piezoelectric film 42, and the detection of the induced charges is used for detecting the force of the touch object.

In some embodiments, the pressure touch unit 40 further includes an operation chip (not shown) disposed on the flexible circuit board 41. When the piezoelectric film 42 is stressed, induced charges are generated on the upper and lower surfaces of the piezoelectric film, charge signal transmission is performed through the upper and lower electrodes 421 and 422, and the induced charges are transmitted to processing devices such as an operation chip through the conductive adhesive 60 and corresponding circuits in the flexible circuit board 41, so that signals can be processed and converted, and a corresponding relationship between touch pressure and signals is established.

In other embodiments, the force sensor may be of other types, such as a strain-type force sensor, a resistive force sensor. In the case of a strain-type force sensor, the force sensor may be a metallic strain gauge or a semiconductor strain gauge. For example, a semiconductor strain gauge includes a semiconductor film and a resistive track formed on the semiconductor film, the resistive track being electrically connected to a flexible circuit board by a conductive paste. The semiconductor film may be a silicon film, a germanium film, or the like. The resistor strip may be formed on the semiconductor film by a semiconductor process. The resistive strip itself, or the resistive strip and the traces in the flexible circuit board, may form a detection circuit. When the strain force sensor is deformed under external force, the resistance is changed, and then the corresponding relation with the touch pressure can be established by detecting the change of the resistance or the voltage change in the detection circuit, so that the detection of the force of a touch object is realized. When the force sensor is a resistance force sensor formed by an organic composite material film doped with conductive particles, electrodes exist on the surface of the composite material film and can be electrically connected with a flexible circuit board in a mode of conductive adhesive, vapor deposition, screen printing and the like. When the force sensor is subjected to pressure perpendicular to the material, the resistance value of the resistance formed between the surface electrodes of the composite film changes, so that the pressure applied to the force sensor can be measured by detecting the change in resistance.

In some embodiments, the flexible circuit board 41 of the pressure touch unit 40 and the flexible circuit board in the capacitive touch unit 20 can be used together, so as to improve the integration degree of the whole touch display device and thin the touch display device.

The flexible circuit board 41 of the pressure touch unit 40 may be in a block shape as shown in fig. 2, may be in a bar shape as shown in fig. 5, and may be in a ring shape as shown in fig. 6. The force sensors may be disposed at a plurality of locations on the flexible circuit board 41. In some embodiments, the display module 30 includes a visible area and a non-visible area located at the periphery of the visible area, and the force sensor is disposed in the non-visible area of the display module 30. The flexible circuit board may contain a plurality of force sensors, such as 1-8.

As shown in fig. 1, the force sensor is located between the flexible circuit board 41 and the display module 30. The force sensor is fixedly adhered to the display module 30 through common adhesive such as optical adhesive 50 such as OCA.

According to the invention, the force sensor is integrated on the back of the display module, and the force sensor is arranged on the flexible circuit board, so that the combination of position and pressure dual detection is realized, the structure is simple and compact, and the man-machine interaction experience handfeel can be improved.

The touch display device can be used for products such as mobile phones, tablet computers, televisions and the like.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims (5)

1. The touch display device comprises a protective cover plate, a capacitive touch unit and a display module, wherein the capacitive touch unit is positioned on one side of the protective cover plate and used for acquiring position information of a touch object;

the force sensor is a piezoelectric sensor, the piezoelectric sensor comprises a piezoelectric film, the flexible circuit board comprises an upper base material, a lower base material and an isolation layer positioned between the upper base material and the lower base material, and the piezoelectric film is positioned between the upper base material and the lower base material;

Electrodes are arranged on two sides of the piezoelectric film, electrode leads are respectively arranged on the upper base material and the lower base material, and the electrodes are bonded with the electrode leads through conductive adhesive; or the upper substrate or the lower substrate is provided with electrodes and electrode leads which are correspondingly and electrically connected with the electrodes, and the piezoelectric film is correspondingly bonded with the electrodes on the flexible circuit board through conductive adhesive.

2. The touch display device of claim 1, wherein the flexible circuit board is bar-shaped, frame-shaped, or block-shaped.

3. The touch display device of claim 1, wherein the display module includes a viewable area and a non-viewable area located at a periphery of the viewable area, and the force sensor is disposed in the non-viewable area of the display module.

4. The touch display device of claim 1, wherein the force sensor is located between the flexible circuit board and the display module.

5. The touch display device of claim 1, wherein the pressure touch unit further comprises an arithmetic chip disposed on the flexible circuit board.