Optical touch module based on lattice grating structures in two vector directions

Abstract

The invention relates to an optical touch module based on lattice grating structures in two vector directions. The optical touch module comprises a laser light source, a waveguide light guide layer, a grating and a photoelectric detector, the waveguide light guide layer is a single layer; the gratings are distributed on the waveguide light guide layer in the form of dot matrix units, and each dot matrix unit adopts two vector direction dot matrix grating structures and comprises a first vector direction dot matrix grating and a second vector direction dot matrix grating which are mutually straight with the waveguide light guide layer; the laser light source outputs incident light with a specific wavelength so as to meet the requirement that the diffraction angle of diffracted light in air is larger than 90 degrees, the diffracted light is incident on the waveguide light guide layer, the two vector direction lattice grating structures couple the diffracted light into the waveguide light guide layer, and two waveguide modes in different directions are generated. Incident light is transmitted to the side wall of the waveguide light guide layer along X and Y coordinate directions and is received by a peripheral photoelectric detector, so that the position of an incidence point of the laser light source is determined. The beneficial effects are that the output efficiency of the touch screen is improved and the screen thickness is reduced.

Description

【Technical field】 [0001] The invention relates to the technical field of touch display devices, in particular to an optical touch module based on two kinds of vector direction lattice grating structures. 【Background technique】 [0002] According to whether or not to touch the screen, touch technology can be divided into contact and non-contact touch technology. According to different touch sensing methods, contact touch technology can be subdivided into resistive, capacitive, acoustic and optical, and non-contact can be subdivided into camera and electromagnetic resonance. [0003] Resistive touch screens use pressure as an input and consist of two transparent sheets coated with a conductive substance, separated by a tiny space containing a particle fulcrum. When the finger touches the surface of the touch screen, due to the pressure, the two thin plates contact and conduct electricity, and the coordinates of the touch point are determined by detecting the voltage change of...

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Problems solved by technology

[0011] At present, there is a touch screen (201910871622.4) based on distributed gratings in a dot matrix structure. Although this touch screen does not require an additional light source and reduces transmission loss to a certain extent, the output efficiency of the touch screen still cannot meet the needs of large-size screens. Requirements, the use of a one-dimensional grating structure requires the use of two layers of waveguide light-guiding layers, which are thicker, and strong reflection will occur between the two layers of waveguide light-guiding layers, and the incident light of the second waveguide light-guiding layer passes through the first waveguide light-guiding layer Coupling consumption of the layer, energy reduction, affect the touch effect; the efficiency of the two-dimensional grating structure is low, and the output efficiency of the touch screen needs to be further optimized

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