A virtual image display device

Abstract

This utility model discloses a virtual image display device, comprising: a touch module; a processing control module; and a display module, which includes a window glass for transmitting imaging light to form a virtual image. The touch module is disposed on the window glass and can form a touch surface on the window glass. The touch module includes a first conductive pixelation unit representing the X-axis direction, a second conductive pixelation unit representing the Y-axis direction, and a double-sided conductive glass substrate, wherein the X-axis and Y-axis are perpendicular to each other. The first conductive pixelation unit and the second conductive pixelation unit are respectively disposed on both sides of the double-sided conductive glass substrate. Each conductive pixelation unit is electrically connected to the processing control module, so that the processing control module can identify the self-capacitance and mutual capacitance changes of each conductive pixelation unit. The display module is connected to the processing control module and can display the position of at least one conductive pixelation unit that has identified a self-capacitance change.

Description

Technical Field

[0001] This utility model relates to optical imaging technology, and in particular to a virtual image display device. Background Technology

[0002] Touchscreens can be classified in several ways: by their working principle and the medium through which they transmit information; by their installation method; by their technical principle; and by their technology.

[0003] 1) Resistive Touchscreen

[0004] Analog resistive touchscreens, commonly known as "resistive screens," are a type of touchscreen controlled by pressure sensing. They employ two layers of conductive ITO (indium tin oxide) plastic film. The two ITO layers have microparticle supports, creating a gap between them when the screen is not pressed, resulting in a non-conductive state. When an operator presses the screen with their fingertip or stylus, the pressure causes the film to concave, deforming and making the ITO layer conductive. The pressure point is calculated by detecting changes in voltage along the X and Y axes, completing the touch processing mechanism. Currently, analog resistive touchscreens come in various types, including 4-line, 5-line, 6-line, and 8-line. More lines mean higher detection precision, but also higher cost. Resistive screens do not support multi-touch, consume more power, have a shorter lifespan, and can experience detection point drift with prolonged use, requiring calibration. However, their simple structure and lower cost allowed them to dominate the touchscreen market before capacitive touchscreens matured.

[0005] The basic principle of digital resistive touchscreens is similar to that of analog ones. However, unlike analog resistive touchscreens which use a uniform ITO layer coated on a glass substrate, digital resistive touchscreens utilize a substrate with ITO stripes. The ITO stripes on the upper and lower substrates are perpendicular to each other. Digital resistive touchscreens are more like simple switches and are therefore often used as membrane switches. Digital resistive touchscreens enable multi-touch.

[0006] 2) Capacitive Touchscreen

[0007] Surface capacitive touchscreens sense touch behavior on the screen surface through electric field sensing. Their panel is a uniformly coated ITO layer, with a wire at each of the four corners connecting to the controller. During operation, a uniform electric field is generated on the touchscreen surface. When a grounded object touches the screen surface, the electrodes sense the change in surface charge and determine the coordinates of the touch point. Surface capacitive touchscreens have a long lifespan and high light transmittance, but they have low resolution and do not support multi-touch. Currently, they are mainly used in large-size outdoor touchscreens, such as public information platforms (POI) and public service (sales) platforms (POS).

[0008] Projected capacitive touchscreens utilize the electrostatic field lines emitted by the touchscreen electrodes for sensing. Projected capacitive sensing technology can be divided into two types: self-capacitance and interactive capacitive. Self-capacitance, also known as absolute capacitance, treats the object being sensed as the other plate of a capacitor. This object induces a charge between the sensing and sensing electrodes, and the position is determined by detecting changes in this coupling capacitance. However, for a single-point touch, the change in capacitance results in only one set of coordinates along the X-axis (horizontal in normal use) and Y-axis (vertical in normal use), and the combined coordinates are unique. If there are two touches on the touchscreen, and these two points are not in the same X-axis or Y-axis, there are two coordinate projections in the X and Y directions respectively, resulting in four combined coordinates. Obviously, only two coordinates are real; the other two are what are commonly known as "ghost points." Therefore, self-capacitive screens cannot achieve true multi-touch.

[0009] Interactive capacitance, also known as cross capacitance, is capacitance generated through the coupling of adjacent electrodes. When a sensed object approaches the electric field lines between one electrode and another, the change in interactive capacitance is felt. When the horizontal electrodes sequentially emit excitation signals, all the vertical electrodes simultaneously receive the signals. This allows us to obtain the capacitance values ​​at all intersections of the horizontal and vertical electrodes, i.e., the capacitance of the entire two-dimensional plane of the touchscreen. When a human finger approaches, it causes a decrease in local capacitance. Based on the data of the change in the two-dimensional capacitance of the touchscreen, the coordinates of each touch point can be calculated. Therefore, even if there are multiple touch points on the screen, the true coordinates of each touch point can be calculated.

[0010] In both types of projected capacitive sensors mentioned above, the sensing capacitor can be designed in a certain way to detect the touch of a finger at any given time. This touch is not limited to one finger, but can also involve multiple fingers. Since 2007, the huge success of Apple's iPhone and iPad series products has led to an explosive development of projected capacitive screens, which have quickly replaced resistive touchscreens and become the mainstream touch technology in the market today.

[0011] 3) Infrared touchscreen

[0012] Infrared touchscreens utilize a densely packed matrix of infrared rays along the X and Y axes to detect and locate user touches. An infrared touchscreen has a circuit board frame mounted in front of the display. Infrared emitters and receivers are arranged around the four sides of the screen, forming a crisscrossing infrared matrix. When a user touches the screen, their finger blocks the horizontal and vertical infrared rays passing through that location, allowing the system to determine the touch point's position on the screen. Infrared touchscreens offer advantages such as high light transmittance, immunity to interference from current, voltage, and static electricity, and high touch stability. However, their accuracy is affected by changes in ambient light and by infrared sources such as remote controls, high-temperature objects, and incandescent lamps. Early infrared touchscreens appeared in 1992 with a resolution of only 32×32, were susceptible to environmental interference leading to malfunctions, and required operation in certain shaded environments. After 20 years of development, advanced infrared touchscreens now have a lifespan exceeding 7 years under normal operating conditions. When tracking finger movements, they meet requirements for accuracy, smoothness, and tracking speed, allowing user handwriting to be smoothly converted into image trajectories and fully supporting handwriting recognition input. Infrared touchscreens are mainly used in various public places, offices, and industrial control applications where there is no infrared interference or strong light interference.

[0013] 4) Sonic wave touchscreen

[0014] Surface acoustic wave (SAW) touchscreens are touch technologies that use sound waves for positioning. Sensors for emitting and receiving sound waves in the X and Y directions are attached to the four corners of the touchscreen, and 45° reflective stripes are etched around the perimeter. When a finger touches the screen, the finger absorbs some of the sound wave energy, and the controller detects the attenuation of the received signal at a certain moment, thereby calculating the position of the touch point.

[0015] Surface acoustic wave (SAW) technology is highly stable and precise. Besides the X and Y coordinates that most touchscreens respond to, it also responds to a unique third axis, the Z-axis, which is the pressure axis. With this function, each touch point is no longer just two digital switch states—touch and no touch—but becomes an analog switch that senses force: the greater the pressure, the wider and deeper the attenuation gap in the received signal waveform. Among all types of touchscreens, only SAW touchscreens possess the ability to sense touch pressure. SAW touchscreens are unaffected by environmental factors such as temperature and humidity, offer high clarity (extremely high resolution), good light transmittance, high durability, good scratch resistance, high responsiveness, and a long lifespan. They maintain clear and bright image quality without drift, require only one calibration during installation, and have good resistance to impacts, making them ideal for public information retrieval and use in offices, government agencies, and relatively clean public places.

[0016] Bending acoustic wave touchscreens are based on sound pulse recognition technology. When an object touches the touchscreen surface, the sensor detects the frequency of the sound wave. By comparing this frequency with a standard frequency pre-stored in a chip, the location of the touch point is determined. This method eliminates false recognitions caused by environmental factors such as clothing, luggage, dust, and insects. While surface touchscreens transmit sound waves along the substrate surface, bending touchscreens transmit sound waves internally within the substrate, making them more resistant to environmental interference. Currently, bending touchscreens are commonly used in kiosks larger than 5 inches, financial equipment, and vending machines.

[0017] Touchscreens displaying virtual images differ from traditional touchscreens displaying real images on an LCD surface. Because the virtual image is displayed at a distance, the touch point and the virtual image's imaging point do not coincide. In fact, the intersection point of the light rays from the virtual image seen by the left eye on the touchscreen does not coincide with the intersection point of the light rays from the virtual image seen by the right eye. This means a one-to-one mapping cannot be established between the touch point and the image point, thus preventing the interaction found in traditional touchscreen solutions. Furthermore, the virtual image's position shifts slightly depending on the viewing position, further complicating the mapping relationship between touch points and image points. Therefore, the mapping problem between touch points and image points in virtual image touchscreen solutions is a critical issue that needs to be addressed. Utility Model Content

[0018] The technical problem to be solved by this utility model is to provide a virtual image display device that improves the convenience of interaction, addressing the shortcomings of the existing technology.

[0019] The technical solution adopted by this utility model to solve the above-mentioned technical problems is: a virtual image display device, comprising:

[0020] The touch module is used to detect the user's touch operations;

[0021] Processing control module; and

[0022] The display module includes a window glass for transmitting imaging light to form a virtual image, and the touch module is disposed on the window glass to form a touch surface on the window glass;

[0023] Its features are:

[0024] The touch module includes a first conductive pixelation unit representing the X-axis direction, a second conductive pixelation unit representing the Y-axis direction, and a double-sided conductive glass substrate, wherein the X-axis and Y-axis are perpendicular to each other. The first and second conductive pixelation units are respectively disposed on both sides of the double-sided conductive glass substrate. Each conductive pixelation unit is electrically connected to the processing control module, so that the processing control module can identify the self-capacitance and mutual capacitance changes of each conductive pixelation unit. The display module is connected to the processing control module and can display the position of at least one conductive pixelation unit that has identified a self-capacitance change.

[0025] By utilizing the self-capacitance and mutual capacitance of the conductive pixelation unit, hover touch and contact touch are realized. The result recognized by the processing and control module during hover touch is displayed on the display module that displays the virtual image to guide the user to make further adjustments or directly touch.

[0026] Furthermore, to facilitate multi-touch operation, the virtual image display device also includes an infrared touch module, which is disposed on the outermost surface of the window glass.

[0027] Preferably, in order to eliminate the effects of reflection and glare from external ambient light, a first quarter-wave plate and a polarizer are arranged sequentially on the outside of the window glass and in a direction away from the window glass, and the infrared touch module is located on the outside of the polarizer.

[0028] Preferably, in order to achieve the floating touch effect of infrared touch, the distance between the plane of the infrared touch module and the polarizer is 3 to 15 mm.

[0029] Preferably, to achieve a distant imaging effect, a first quarter-wave plate and a polarizer are arranged sequentially on the outer side of the window glass and in a direction away from the window glass, and a reflective polarizer and a second quarter-wave plate are also provided on the inner side of the window glass, with the touch module located between the window glass and the reflective polarizer.

[0030] Preferably, in order to achieve a distant image effect, a second antireflection film is provided on the side of the second quarter-wave plate away from the reflective polarizer.

[0031] Compared with the prior art, the advantages of this utility model are: by utilizing the self-capacitance and mutual capacitance of the conductive pixelation unit, hover touch and contact touch are realized, and the results of hover touch recognition are displayed on the display module that displays virtual images to guide the user to make further adjustments or contact touch. Attached Figure Description

[0032] Figure 1 This is an exploded view of the virtual image display window according to the first embodiment of the present invention;

[0033] Figures 2-4This is a schematic diagram illustrating the self-capacitance and mutual capacitance implementation principle of the touch module in the first embodiment of this utility model;

[0034] Figure 5 This is a schematic block diagram of the dashed-line imaging optical system according to the first embodiment of this utility model;

[0035] Figure 6 This is an exploded view of the virtual image display window according to the second embodiment of the present invention. Detailed Implementation

[0036] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions.

[0037] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Since the embodiments disclosed in this utility model can be arranged in different directions, these terms indicating direction are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0038] Example 1

[0039] To address the mapping problem between touch points and image points in the aforementioned virtual image touch control schemes, this invention provides a touch interaction scheme for a virtual image imaging system.

[0040] See Figure 1 and Figure 5A virtual image display device includes a touch module 1, a processing and control module 2, and a display module 3. The display module 3 has a window glass 31. A first quarter-wave plate 32 (QWP) and a polarizer 33 (POL) are arranged sequentially on the outer side of the window glass 31 (the outer side of the window glass 31 refers to the side of the window glass 31 facing away from the device) and away from the window glass 31. In addition, a first anti-reflective film 34 (AR) can be provided on the side of the polarizer 33 away from the first quarter-wave plate 32. This combination of films located on the outer side can eliminate the effects of reflection and glare from external ambient light. The touch module 1 is located inside the window glass 31 (the outside of the window glass 31 refers to the side of the window glass 31 facing the inside of the device). A reflective polarizer 35 (RP) and a second quarter-wave plate 36 are also provided inside the window glass 31. The touch module 1 is located between the window glass 31 and the reflective polarizer 35. In addition, a second anti-reflection film 37 can be provided on the side of the second quarter-wave plate 36 away from the reflective polarizer 35. These internal film materials are combined with the optical film inside the virtual image optical module to achieve a far-image effect.

[0041] The contents disclosed in Chinese Patent Application No. 202411086278.5 are incorporated herein by reference in their entirety (where touch module 1 corresponds to touch device, processing control module 2 corresponds to control device, display module 3 corresponds to display body, and window glass 31 corresponds to inner window glass 13), and therefore the composition of the imaging optical system will not be described in detail here.

[0042] The first conductive pixelation unit 11 in the X-axis direction (a conductive pixelation unit is a technology or phenomenon that distributes or prepares conductive materials in a pixelated form to achieve a specific function) and the second conductive pixelation unit 12 in the Y-axis direction of the touch module 1 are respectively placed on both sides of the double-sided conductive glass substrate 13, as shown in side view 2 and top view 3. The correspondence between the X-axis and Y-axis directions represented by the two types of pixelation units and the window glass 31 can be found in [reference needed]. Figure 1 As shown, the X-axis typically corresponds to the horizontal direction from the user's perspective during normal use, and the Y-axis corresponds to the vertical direction from the user's perspective during normal use. The mutual and self-capacitance between each pixelation unit are represented by... Figure 4 The capacitance is represented by Cm and Cs. Self-capacitance refers to the capacitance formed between a single pixel unit and the reference ground (or surrounding environment). Each pixel can be considered as an electrode, and its self-capacitance is the capacitance value generated between the electrode and "ground" due to the charge storage capacity. Mutual capacitance refers to the capacitance generated between two adjacent or related pixel units due to charge induction. When two pixels serve as the driving electrode and the sensing electrode respectively, the capacitance between them is mutual capacitance.

[0043] The first conductive pixelation unit 11 can have m units, corresponding to m positions along the X-axis; the second conductive pixelation unit 12 can have n units, corresponding to n positions along the Y-axis. Optionally, for a conventional screen, m can be 1200 and n can be 1600.

[0044] When a finger approaches a pixelated unit, the capacitance of that pixelated conductive unit changes (generally, the capacitance value increases), which is recognized by the connected processing and control module 2, triggering hover touch. When the finger touches the touch screen, it causes a change in mutual capacitance (generally, the capacitance value decreases), triggering contact touch. Thus, hover touch and contact touch are simultaneously implemented in the same touch module 1.

[0045] Unlike traditional methods that directly attach the physical image to the touchscreen for touch point position feedback, this invention's virtual image touch solution displays the touch point position on the virtual image in real time, similar to mouse control. This allows the touch points to establish a one-to-one mapping without relying on the correspondence between the user's left and right eyes and the virtual image display points. Furthermore, by displaying the real-time touch point position, the user learns and corrects their position, thus subjectively establishing a correspondence between the touch point and the display point.

[0046] Considering that typical capacitive touch modules simultaneously perform a click event upon finger contact, to achieve real-time feedback of the touch point position to the virtual image in a manner similar to mouse control, the following steps are specifically included:

[0047] Step 1) The user's finger approaches at least one of the conductive pixelation units of the touch module 1, but does not touch the touch module 1 (floating touch). The distance between the finger and the touch module 1 can be selected as 10mm to 30mm. The corresponding conductive pixelation unit of the touch module 1 undergoes a self-contained change and is recognized by the processing and control module 2 connected to it. The finger position is the coordinate value of the coordinate axis formed by the X-axis and Y-axis.

[0048] Step 2), the processing control module 2 sends the detected finger position to the display module 3 and displays it on the virtual image; the display method can be to overlay the X-axis coordinates and Y-axis coordinates corresponding to the current position of the detected finger on the virtual image in a cursor-like manner.

[0049] Step 3): Based on the feedback from display module 3, the user confirms whether the position they are about to press is the target pressing position. If it is, they directly press touch module 1 (in this case, mutual capacitance). If not, they adjust accordingly before pressing touch module 1 (in this case, mutual capacitance). In this step, clicking, swiping, long-pressing, and other events are triggered when pressing (contact touch).

[0050] Example 2

[0051] See Figure 6 In this embodiment, the difference from Embodiment 1 is that, in order to solve the problem that the floating touch cannot achieve multi-touch in Embodiment 1, an infrared touch module 4 is added to the outermost layer of the film on the outer side of the window glass 31. To achieve the floating touch effect of infrared touch, the infrared light emitter and the plane where the infrared structure module is located need to be placed at a certain distance outside the outermost film surface, preferably 3-15mm.

[0052] The principle by which the infrared touch module 4 achieves multi-touch detection is the same as that of the infrared touch screen in the background technology.

Claims

1. A virtual image display device, comprising: A touch module (1) is used to detect the user's touch operation; Processing control module (2); as well as The display module (3) includes a window glass (31) for transmitting imaging light to form a display virtual image, and the touch module (1) is disposed on the window glass (31) and can form a touch surface on the window glass (31); Its features are: The touch module (1) includes a first conductive pixelation unit (11) representing the X-axis direction, a second conductive pixelation unit (12) representing the Y-axis direction, and a double-sided conductive glass substrate (13), wherein the X-axis and Y-axis are perpendicular to each other, the first conductive pixelation unit (11) and the second conductive pixelation unit (12) are respectively disposed on both sides of the double-sided conductive glass substrate (13), and each conductive pixelation unit is electrically connected to the processing control module (2) so that the processing control module (2) can identify the self-capacitance and mutual capacitance changes of each conductive pixelation unit; The display module (3) is connected to the processing control module (2) and can display the position of at least one conductive pixelated unit that has undergone self-contained change.

2. The virtual image display device of claim 1, wherein: The virtual image display device also includes an infrared touch module (4), which is disposed on the outermost surface of the window glass (31).

3. The virtual image display device of claim 2, wherein: The first quarter-wave plate (32) and the polarizer (33) are arranged sequentially on the outside of the window glass (31) and in a direction away from the window glass (31), and the infrared touch module (4) is located on the outside of the polarizer (33).

4. The virtual image display device of claim 3, wherein: The distance between the plane of the infrared touch module (4) and the polarizer (33) is 3 to 15 mm.

5. The virtual image display device of claim 1, wherein: A first quarter-wave plate (32) and a polarizer (33) are arranged sequentially on the outside of the window glass (31) and in a direction away from the window glass (31). A reflective polarizer (35) and a second quarter-wave plate (36) are also provided on the inside of the window glass (31). The touch module (1) is located between the window glass (31) and the reflective polarizer (35).

6. The virtual image display device of claim 5, wherein: A second antireflection film (37) is provided on the side of the second quarter-wave plate (36) away from the reflective polarizer (35).

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