Display and touch integrated non-contact virtual touch screen with light guide type backlight plate structure
Technical Field
The invention relates to the technical field of computer interaction, in particular to a non-contact touch screen, and specifically relates to a display and touch integrated non-contact virtual touch screen structure with a light guide type backlight plate structure and an implementation method thereof.
Background
Touch technology is an interactive input technology with great development prospect, and touch screen technology develops rapidly in recent years. At present, touch screen technologies have been developed to nearly twenty types, and touch screens with relatively mature technologies mainly include resistive type, capacitive type, surface acoustic wave type, infrared type and the like. These touch devices are flat touch screens, and all touch devices need to directly touch the surface of the touch screen to complete touch. The existing inquiry terminals of ATM machines, airports and railway stations in public places, the touch screens and keys on ticket dispensers, and the control buttons of elevators, access controls and the like can generate cross infection of viruses and bacteria. Application requirements call for new techniques for contactless air operation. The existing touch technology (including various methods for acquiring and processing images) cannot reliably, effectively and conveniently realize non-contact air operation of buttons, keyboards and touch screens. Touch screens such as resistive, surface acoustic wave, infrared, etc. must be touched to operate; the distance for realizing non-contact operation of the capacitive screen is short, misoperation is easy to occur, and practicability cannot be realized; devices using image processing techniques are either unavoidable for false occlusion or are difficult to install at the application site. The multi-layer infrared scanning structure is arranged around the screen, so that non-contact aerial virtual touch of the screen can be reliably realized, but the thickness of the screen can be increased.
Accordingly, the prior art is in need of improvement and development.
Disclosure of Invention
The invention aims to solve the defects of the prior art, provides a display-touch integrated non-contact virtual touch screen with a light guide type backlight plate structure, aims to modify the structure of the prior liquid crystal screen to enable the prior liquid crystal screen to have an infrared scanning function, can reliably and conveniently realize the air separation operation of the display screen, solves the problem of cross infection of viruses and bacteria possibly generated by clicking the touch screen in public places, can eliminate a multilayer infrared scanning structure frame around the prior screen, and can be suitable for various liquid crystal screens comprising a plane screen and a curved screen to improve the application range.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention discloses a display touch control integrated non-contact virtual touch screen with a light guide type backlight plate structure, which sequentially comprises the following components in sequence from outside to inside: an outer polarizer, a filter film, an outer orientation layer, a liquid crystal layer, an inner orientation layer, a thin film transistor substrate, an inner polarizer, a light guide and diffusion plate, a light source and a reflector; the filter film, the outer orientation layer and the inner orientation layer are provided with a plurality of pixel points, and each pixel point on the filter film comprises a red, green and blue three-primary-color area; a light valve for controlling the tricolor region of each pixel point on the orientation layer is arranged on the thin film transistor substrate; the light guide light-diffusing plate comprises a light-diffusing layer, a light guide layer and a light reflecting plate, and is characterized in that:
an infrared region is added in the three primary colors of each pixel point on the filter film, the outer orientation layer and the inner orientation layer and is used for transmitting infrared light;
for a normally black liquid crystal display screen, each infrared area on the outer orientation layer and the inner orientation layer is provided with an electrode, and the electrodes and a circuit on the thin film transistor substrate or an external circuit form an infrared light valve;
the reflecting plate is an infrared-transmitting visible light reflecting layer;
an infrared transmitting and receiving pair tube array is arranged behind the infrared transmitting and reflecting visible light layer; the infrared light emitted by each infrared pair tube in the infrared receiving and transmitting tube array corresponds to a plurality of pixel points.
The invention relates to a display touch integrated non-contact virtual touch screen based on a light guide type backlight plate structure, which is characterized in that non-contact virtual touch is realized according to the following steps:
step 1, starting a liquid crystal display, and opening infrared light valves corresponding to all pixel points of a normally black liquid crystal display screen and applying an electric field to an orientation layer; for a normally white type liquid crystal display screen, a normally white state is maintained;
step2, performing infrared scanning according to a certain period, and performing the following processing on each scanning in each period:
step2.1, scanning all the infrared geminate transistors, controlling the infrared emission tube to emit infrared light for each infrared geminate transistor, and transmitting the infrared light from a screen after sequentially passing through a light guide light scattering plate, an inner polarizing plate, an infrared light valve of a thin film transistor base body, an inner orientation layer, a liquid crystal layer, an outer orientation layer, an infrared region of a light transmission film and an outer polarizing plate;
2.2, if the hand is shielded at a certain distance in front of the screen, the transmitted infrared light is reflected by the hand to enter the screen, and then sequentially passes through an outer polarizing plate, an infrared region of a filter film, an outer orientation layer, a liquid crystal layer, an inner orientation layer, an infrared light valve of a thin film transistor matrix, an inner polarizing plate and a light guide light scattering plate and is received by an infrared pair tube; if the hand is not blocked, the reflected light is zero;
obtaining a normalized voltage signal according to the reflected light received by the infrared receiving tube;
calculating the hand shielding distance corresponding to each infrared receiving tube according to the corresponding relation between the voltage signal and the shielding distance;
determining the shielding area of the hand according to the shielding distance of the hand corresponding to each infrared receiving tube, further decomposing to obtain the position of each finger and the shielding area thereof, and calculating the angle and the front end width of each finger;
obtaining a square area of the front end of each finger according to the width of the front end of each finger; the number set of infrared pair tubes with shielding in any square area is set as {1,2, …, i, …, n }, and the coordinate set corresponding to the infrared pair tubes is { (x)1,y1),(x2,y2),…,(xi,yi),…,(xn,yn) The voltage signals of the infrared receiving tubes are integrated into { V }1,V2,…,Vi,…,VnCalculating three-dimensional coordinates (x, y, d) of the finger touch points according to the formula (1), and further obtaining various touch operations according to the three-dimensional coordinates of the finger touch points:
in the formula (1), xiRepresenting the abscissa, y, of the ith IR pair with a shadow in a square regioniRepresents the ordinate of the longitudinal axis of the i-th infrared pair tube with a shield in the square area, ViAnd indicating the voltage signal of the ith infrared receiving tube with the shading in the square area.
Compared with the prior art, the invention has the beneficial effects that:
1. according to the non-contact virtual touch screen structure, the infrared transceiving geminate transistors are arranged behind the backlight plate of the existing liquid crystal screen, the infrared region is added in each pixel point of the display screen except for the three primary color region, so that the non-contact virtual touch screen structure has an infrared scanning function, the touch points are positioned by using a recognition and positioning algorithm, the display screen can be reliably and conveniently separated from the air, and the problem of cross infection of viruses and bacteria possibly generated when the touch screen is clicked in a public place is effectively solved.
2. The non-contact virtual touch screen can set the touch distance according to the needs, can be applied to a plane screen and a curved screen, and has a wide application range.
3. According to the invention, the shielding area of the hand is determined according to the shielding distance of the hand corresponding to each infrared receiving tube, the position of each finger and the shielding area are obtained through further decomposition, the angle and the front end width of each finger are calculated, and the square area of the front end of each finger is obtained according to the front end width of each finger, so that non-contact accurate positioning is realized.
4. The non-contact virtual touch screen integrates display and touch, greatly reduces the thickness of the display touch screen, and has wide application places.
Drawings
FIG. 1 is a schematic diagram of an internal structure of a liquid crystal display panel in the prior art;
FIG. 2 is a schematic diagram of the internal structure of the touch screen of the present invention;
FIG. 3a is a schematic view of an arrangement of regions of a filter according to the present invention;
FIG. 3b is a schematic view of another arrangement of regions of the filter according to the present invention;
FIG. 4 is a schematic view of the filter area and the light valve space correspondence of the present invention;
FIG. 5 is a schematic diagram of an infrared pair tube calibration process according to the present invention;
FIG. 6a is a schematic view of finger touch positioning according to the present invention;
FIG. 6b is a schematic diagram of a square area for finger touch location according to the present invention;
reference numbers in the figures: 1 an outer polarizing plate; 2, filtering the light film; 3 an outer alignment layer; 4 a liquid crystal layer; 5 an inner orientation layer; 6a thin film transistor substrate; 7 an inner polarizing plate; 8 light guide light diffusion plate; 9, a power supply; 10a reflector; 10a an infrared-transmitting, reflective and visible light layer; 11 infrared receiving and transmitting pair tube array; 12 a liquid crystal display screen; 13 matte infrared shading plates.
Detailed Description
In the embodiment, the display touch control integrated non-contact virtual touch screen with the light guide type backlight plate structure has an infrared scanning function by modifying the existing liquid crystal screen structure, and a touch control point is positioned by utilizing an identification positioning algorithm; during operation, the finger is 30mm to 50mm away from the screen (the touch distance can be set), so that non-contact virtual touch can be realized, the problem of cross infection of viruses and bacteria possibly generated when the touch screen is clicked in a public place is solved, meanwhile, the multi-layer infrared scanning structure frame around the original screen is removed, the touch screen can be applied to various liquid crystal screens comprising a plane screen and a curved screen, the appearance is simple and elegant, and the application range is wider.
As shown in fig. 1, the liquid crystal panel sequentially includes, from outside to inside, an outer polarizer 1, a filter 2, an outer alignment layer 3, a liquid crystal layer 4, an inner alignment layer 5, a thin film transistor substrate 6, an inner polarizer 7, a light guiding and diffusing plate 8, a power supply 9, and a reflector 10; wherein, the outer polarizer 1 and the inner polarizer 7 are normally black liquid crystal panels if the polarization directions thereof are parallel to each other, and are normally white liquid crystal panels if the polarization directions thereof are perpendicular to each other; a plurality of pixel points are arranged on the filter film 2, the outer orientation layer 3 and the inner orientation layer 5, and each pixel point on the filter film 2 comprises a tricolor region of red R, green G and blue B; a light valve for controlling the tricolor region of each pixel point on the orientation layer, namely a red light valve R ', a green light valve G ' and a blue light valve B ', is arranged on the thin film transistor substrate 6; the light guide light scattering plate 8 comprises a light scattering layer, a light guide layer and a light reflecting plate 10;
in specific implementation, the display-touch integrated non-contact virtual touch screen of the light guide type backlight plate structure is formed by structurally modifying a liquid crystal display, as shown in fig. 2; an infrared region I is added to the three primary colors of each pixel point on the filter film 2, the outer orientation layer 3 and the inner orientation layer 5 and is used for transmitting infrared light; r, G, B, I can be rectangular fig. 3a, square fig. 3b or any other shape, in this embodiment, the arrangement shape is rectangular fig. 3 a; for a normally black liquid crystal display screen, electrodes are arranged in each infrared area on the outer orientation layer 3 and the inner orientation layer 5, and the electrodes and a circuit or an external circuit on the thin film transistor substrate 6 form an infrared light valve I'; the arrangement shapes and the sequence of the four light valves R ', G ', B ', I ' are spatially corresponding to the R, G, B, I areas one by one, as shown in fig. 4, the colors of the light passing through the red R, green G, and blue B areas are controlled to be red, green, and blue, respectively, the light valves R ', G ', B ' control the intensity of the light passing through each area, and each pixel can display various colors according to the three primary color principle; the area I can only transmit infrared light, the open state of the infrared light valve I 'indicates that the infrared light can be transmitted out of the infrared area I, and the closed state of the infrared light valve I' indicates that the infrared light cannot be transmitted out; for a normally white liquid crystal display, the infrared light valve I' is kept in a normally open state;
the arranged reflecting plate 10 is an infrared-transmitting visible light reflecting layer 10 a; an infrared transmitting and receiving pair tube array 11 is arranged behind the infrared transmitting and reflecting visible light layer 10 a; the infrared light emitted by each infrared pair tube in the infrared receiving-transmitting pair tube array 11 corresponds to a plurality of pixel points.
In this embodiment, a process of using the display-touch integrated non-contact virtual touch screen with the light guide type backlight structure is to perform initialization calibration processing first, and set a non-contact shielding distance as D, in this embodiment, D is 50 mm. Shielding the screen at different distances from 0 to D by using the infrared reflection characteristic of the matte infrared light shielding plate 13 and the approach of the hand, obtaining the response voltage at each distance as shown in FIG. 5, and performing normalization processing on the response voltage; by utilizing the piecewise linear interpolation method, the relation between the normalized response voltage and the shielding distance of the infrared geminate transistors can be obtained, so that the shielding distance of the infrared geminate transistors can be accurately obtained through the normalized response voltage.
In this embodiment, the display-touch integrated non-contact virtual touch screen of the light guide type backlight plate structure realizes non-contact virtual touch by the following steps:
step 1, starting the liquid crystal screen, and opening the infrared light valves corresponding to all pixel points and applying an electric field to the orientation layer for the normally black liquid crystal display screen; for a normally white type liquid crystal display screen, a normally white state is maintained;
step2, performing infrared scanning according to a certain period, and performing the following processing for each scanning in each period, wherein in the embodiment, the scanning period is 0.01 s:
step2.1, scanning all the infrared geminate transistors, controlling the infrared emission tube to emit infrared light for each infrared geminate transistor, and transmitting the infrared light from a screen after sequentially passing through the light guide light scattering plate 8, the inner polarizing plate 7, the infrared light valve of the thin film transistor substrate 6, the inner orientation layer 5, the liquid crystal layer 4, the outer orientation layer 3, the infrared region of the light transmission film 2 and the outer polarizing plate 1;
step 2.2, if the hand of a person is shielded at a certain distance in front of the screen, as shown in fig. 6a, the transmitted infrared light is reflected by the hand of the person and enters the screen, and then sequentially passes through the outer polarizing plate 1, the infrared region of the filter film 2, the outer orientation layer 3, the liquid crystal layer 4, the inner orientation layer 5, the infrared light valve of the thin film transistor substrate 6, the inner polarizing plate 7 and the light guide and diffusion plate 8, and is received by the infrared pair tube; if the hand is not blocked, the reflected light is zero;
obtaining a normalized voltage signal according to the reflected light received by the infrared receiving tube; according to the method for acquiring the shielding distance of the infrared pair tubes, calculating to obtain the hand shielding distance corresponding to each infrared receiving tube;
determining the shielding area of the hand according to the shielding distance of the hand corresponding to each infrared receiving tube, further decomposing to obtain the position of each finger and the shielding area thereof, and calculating the angle and the front end width of each finger;
obtaining a square area of the front end of each finger according to the width of the front end of each finger, as shown in fig. 6 b; the number set of infrared pair tubes with shielding in any square area is set as {1,2, …, i, …, n }, and the coordinate set corresponding to the infrared pair tubes is { (x)1,y1),(x2,y2),…,(xi,yi),…,(xn,yn) The voltage signals of the infrared receiving tubes are integrated into { V }1,V2,…,Vi,…,VnAnd calculating three-dimensional coordinates (x, y, d) of the finger touch points according to the formula (1), and further obtaining various touch operations according to the three-dimensional coordinates of the finger touch points.
In the formula (1), xiRepresenting the abscissa, y, of the ith IR pair with a shadow in a square regioniRepresents the ordinate of the longitudinal axis of the i-th infrared pair tube with a shield in the square area, ViAnd indicating the voltage signal of the ith infrared receiving tube with the shading in the square area.