TWI387913B - Optical touch device and its control method - Google Patents

Description

Optical touch device and control method thereof

The invention relates to an optical touch device for optically detecting the movement of an input device to generate a signal. The invention also relates to a method of controlling the device.

Touch devices have become common electronic components today, and can be found, for example, in touchpads of notebook computers, or touch screen or touch panels such as automated teller machines, personal digital assistants, electronic dictionaries, and the like. and many more. At present, various touch devices sense the position of the touch in a resistive or capacitive manner. The resistive drive principle is to use the voltage drop method to find the coordinate axis. When the resistive touch screen is touched, the voltage drop occurs due to the loop being turned on, and in the horizontal and vertical directions of the panel, with the position The voltage drop is different, so the controller can calculate the coordinates based on the voltage drop. The capacitive structure is based on ITO (Indium Tin Oxide) glass. The driving principle is to discharge at the four corners of the ITO glass to form a uniform electric field on the surface. When a conductive object, such as a finger, conducts a small amount of current. When it is lost, the controller calculates the ratio of current loss and further calculates the X-axis and Y-axis coordinates.

The object of the present invention is to provide a new optical touch device whose driving principle is neither resistive nor capacitive, but optically detecting the movement of the input device. Therefore, the input device does not need to apply to the screen or the touchpad. Pressure does not need to be electrically conductive. Moreover, the touch device of the present invention does not require complicated components and processes for fabrication, and the cost is much lower than that of a conventional resistive or capacitive touch device.

A second object of the present invention is to provide a method of controlling a touch device.

To achieve the above objective, in one embodiment of the present invention, an optical touch device includes: a light guiding module including an optical information extraction position, the light guiding module guiding light to Optical information is extracted from the position, and optical information is generated according to light input or reflected from the optical information extraction position; and an image sensing module senses optical information generated by the light guiding module, and according to the optical information Optical information to generate electronic signals.

In the above embodiment, an internal infrared light source may be provided. Moreover, a set of lenses can be disposed between the light guiding module and the image sensing module. In addition, a feedback control circuit can be further provided to feedback control the brightness of the internal light source according to the optical information generated by the light guiding module. The electronic signals generated by the image sensing module can be processed by a processing circuit to generate a signal control cursor, or to control the actions of other circuits, or to generate three-dimensional information.

In addition, according to another embodiment of the present invention, a method for controlling an optical touch device includes: providing a light guiding module including an optical information extraction position; and causing the light guiding module to be based on the optical information Extracting light input or reflected to generate optical information; and sensing optical information generated by the light guiding module, and generating an electronic signal according to the optical information.

The purpose, technical content, features and effects achieved by the present invention will be more readily understood by the detailed description of the embodiments.

The drawings in the present invention are intended to be illustrative, and are intended to represent a structural and functional relationship between the elements, rather than limiting the shape of the elements or the relationship therebetween. The optical touch device of the present invention can be applied to a touch panel, a touch screen, or other control purposes. In fact, the optical touch device of the present invention does not absolutely require "touch" control. However, one of the objects of the present invention is to provide another solution for the existing touch device, and therefore the term "touch device" is still used.

Referring to FIG. 1 , the optical touch device 10 of the present invention basically includes a light source 12 , a light guiding module 14 , and an image sensing module 16 , and an input device 20 is disposed outside. The input device 20 can be any item, such as a finger, a pen, or the like, without necessarily being a dedicated part of the optical touch device 10; the input device 20 need not be electrically conductive. The function of the light source 12 is to project light into the light guiding module 14, the position of which is not necessarily as shown, but may be at other positions, such as directly above or above the touch surface 141. If the natural light source is strong enough, the light source 12 can also be omitted; however, it is generally preferable to provide the light source 12, and it is preferable to use an infrared light source to stabilize the light brightness. The function of the light guiding module 14 is to transmit the moving state of the input device 20 to the image sensing module 16; the light guiding module itself has been a practical technology, and can be plastic injection molding, inkjet technology, or imprint technology. Production, the production method is not the focus of this case, so it will not be explained in detail. For example, 稜鏡 is one of the simpler forms of the light guiding module 14. In a more complicated form, the light guide module 14 includes a light guide plate (not shown) for converting a linear light source emitted from the light source 12 into a refractive planar light source, uniformly projecting to the touch surface 141, and touch The input or reflected light received by the control surface 141 is transmitted to the image sensing module 16 to enable the image sensing module 16 to capture optical information about the movement of the input device 20. Preferably, the reflective material 21 can be added to the front end of the input device 20, so that the optical information captured by the image sensing module 16 can be more correct. The input device 20 does not need to apply pressure to the touch surface 141, so it is not absolutely necessary to directly contact the touch surface 141. Similar to the reason for using the term "touch device", the term "touch surface" is used in the present invention, and does not mean that the input device 20 must be in contact with the touch surface 141, but rather that the function is similar to the touch of the prior art. Board, touch screen, etc.

After the image sensing module 16 captures the optical information, the information can be converted into an electronic signal and transmitted to the processing circuit 30. Depending on the application of the optical touch device 10, the output signal of the processing circuit 30 can be used for different purposes. For example, when the optical touch device 10 is a touch panel on a notebook computer, the output signal of the processing circuit 30 can be used. To control the movement of the cursor 41 on the display screen 40; when the optical touch device 10 is a touch screen on the automatic teller machine, it can be used to control other devices (not shown) to perform actions such as transferring funds and the like.

The optical information captured by the image sensing module 16 is two-dimensional information; if only the movement on the two-dimensional plane needs to be calculated, for example, simply controlling the movement of the cursor 41 is sufficient. If other functions are provided according to the three-dimensional movement of the input device 20, for example, on the screen menu, more than two sensors can be disposed in the image sensing module 16, and according to the received image, two senses The relative distance between the detectors, the focal length of the sensor, and the like, the three-dimensional movement of the input device 20 is calculated. In detail, as shown in Fig. 2, it is assumed that the center position distance between the left and right sensors is T , the focus distance of the sensor is f , the image contains an object, and the object is obtained on the left sensor. The x coordinate in the dimensional image is x _l , and the x coordinate in the 2D image obtained by the sensor on the right is x _r (assuming the center position of the sensor is the origin, then x _{r is} at the center of the right sensor The left side of the position is a negative value), and the distance of the object from the sensor is Z , according to the similar triangle theorem, x _l /f = X/Z , and - x _r /f =( TX ) /Z

Therefore, the three-dimensional information of the object can be obtained: X = ( T × x _l ) / ( x _{l -} x _r ) Y = ( T × y _l ) / ( x _{l -} x _r ) (where y _l is not in the figure Shown) Z = f ×[ T /( x _l - x _r )]

In this way, 卽 can generate three-dimensional information of the object.

Of course, the above calculation method is only one of the feasible methods. In addition to the above methods, other methods can be used to calculate the three-dimensional information. How to calculate 3D information is not the focus of this case, so all possible practices and details will not be described. The main point is that the present invention provides a different dimension of information than the conventional touch device, which makes the application more widely.

Please refer to Fig. 3, which is another embodiment of the present invention. The optical touch device 10 of the present embodiment further includes a lens module 15 and a feedback control circuit 17 in addition to the light source 12, the light guide module 14, and the image sensing module 16. One or more lenses 151-152 may be included in the lens module 15 to assist the image sensing module 16 to capture images more accurately. The function of the feedback control circuit 17 is to adjust the brightness of the light source 12. When the light sensed by the image sensing module 16 is too weak, so that the sensing effect is not good, the feedback control circuit 17 The brightness of the light source 12 can be adjusted according to the condition of the image sensing module 16.

In the above-mentioned first and third figures, the input device 20 is drawn to be much smaller than the touch surface 141, but this does not mean that the area of the input device 20 must be smaller than the area of the touch surface 141. FIG. 4 illustrates another embodiment of the present invention. As shown, the input device 20 (eg, a finger) of the present embodiment has an area that shields most or all of the area of the touch surface 141. By detecting the movement of the surface pattern of the input device 20 (e.g., the movement of the fingerprint), two or three dimensional information can be generated for, for example, controlling the cursor, selecting options in the menu, and the like. Since the input device 20 can cover most of the area of the touch surface 141, in the embodiment, it is not absolutely necessary to provide the touch surface 141, that is, it can only be an opening on the casing 11. Optical information can be extracted at this location whether or not the touch surface 141 is provided or only an aperture is provided. In some cases, the function of providing the touch surface 141 is mainly to prevent external dust from falling into the body and causing pollution; facilitating the recognition of the movement of the input device 20 is secondary. In other cases, the touch surface 141 itself is a part of a button that can be pressed to provide other control functions; at this time, as a function of the button, it is convenient to recognize the function of the input device 20, which is a secondary .

In the embodiment shown in FIG. 4, in order to further reduce the volume of the entire optical touch device, the light guiding module 14 and the lens module 15 may be integrated into one body. Of course, depending on the design of the device itself, it may be separated or the lens module 15 may not be provided.

The optical touch device of FIG. 4 can be applied to, for example, a smaller electronic device. Such as a mobile phone, a personal digital assistant, a portable music player, etc.; Figure 5 shows one of the application examples, the optical touch device can be disposed in the mobile phone (not shown), the touch surface 141 or the opening For example, it can be set under the display screen of the mobile phone and above the button.

The present invention has been described with reference to the preferred embodiments thereof, and the present invention is not intended to limit the scope of the present invention. For those skilled in the art, various equivalent changes can be immediately considered within the spirit of the invention. For example, each component shown may be added with other additional components that do not affect its main function; the processing circuit 30 is illustrated as an external component of the optical touch device 10, and may be integrated into an internal component; a feedback control circuit The input signal of 17 can be taken from the image sensing module 16, or can be retrieved from the processing circuit 30, and the like. All of these have the possibility of various equivalent changes. Equivalent changes or modifications of the concept and spirit of the invention are intended to be included within the scope of the invention.

10‧‧‧Optical touch device

11‧‧‧Shell

12‧‧‧Light source

14‧‧‧Light guide module

141‧‧‧ touch surface

15‧‧‧ lens module

151,152‧‧ lens

16‧‧‧Image Sensing Module

17‧‧‧Feedback Control Circuit

20‧‧‧ Input device

21‧‧‧Reflective material

30‧‧‧Processing Circuit

40‧‧‧ Display screen

41‧‧‧ cursor

Figure 1 is a first embodiment of the present invention.

Figure 2 shows how to calculate 3D coordinate information.

Figure 3 is a second embodiment of the present invention.

Figure 4 is a third embodiment of the present invention.

Fig. 5 is an application example of the embodiment of Fig. 4.

10‧‧‧Optical touch device

12‧‧‧Light source

14‧‧‧Light guide module

141‧‧‧ touch surface

16‧‧‧Image Sensing Module

20‧‧‧ Input device

21‧‧‧Reflective material

30‧‧‧Processing Circuit

40‧‧‧ Display screen

41‧‧‧ cursor

Claims (18)

An optical touch device includes: an internal light source that emits a linear light; and a light guiding module that converts at least a portion of the linear light into a planar light and guides it to an optical information extraction position, and The optical information extracts optical information that is transmitted or reflected by the position to generate optical information, wherein the optical information is related to movement of an input device; and an image sensing module senses optical information generated by the light guiding module, and according to The optical information is used to generate an electronic signal; and a lens module includes a first lens between the optical information extraction position and the light guiding module, and a second lens interposed between the light guiding module and the optical lens Between the image sensing modules, wherein the light guiding module has a slope opposite to the optical information extraction position, and the slope has a relative angle with one of the working surfaces of the optical information extraction position, so that at least Part of the linear light penetrates the slope, is converted into the planar light, and is guided to the optical information extraction position, and a portion of the planar light is reflected from the optical information extraction position to the oblique And further by the inclined surface, the reflective portion of the light plane, the portion to the image sensor module. The optical touch device of claim 1, wherein the internal light source is an infrared light source. The optical touch device of claim 2, wherein the light guiding module has a trapezoidal cross section. The optical touch device of claim 1, wherein the electronic signal is output to a processing circuit to generate three-dimensional information. The optical touch device of claim 4, wherein the image sensing module comprises at least two image sensors, the relative distance is T , and the focus distance of the sensor is f , wherein the three-dimensional information is : X = (T × xl) / (xl - xr) ; Y = (T × yl) / (xl - xr) ; and Z = f × [T / (xl - xr)] ; where xl and yl are One of the image sensors senses the two-dimensional information, and xr and yr are the two-dimensional information sensed by the other image sensor. The optical touch device of claim 1, further comprising an input device, one of the input devices being of a reflective material. The optical touch device of claim 1, further comprising a feedback control circuit for feedback controlling the brightness of the internal light source according to the optical information generated by the light guiding module. The optical touch device of claim 7, wherein the feedback control circuit receives a signal from the image sensing module or receives a signal from the processing circuit. The optical touch device of claim 1, wherein the optical information extraction position is a surface or an opening. The optical touch device of claim 1, wherein the optical information extraction location is a surface and the surface is a portion of a pushable button. The optical touch device of claim 1, wherein at least a majority of the area of the optical information extraction location is obscured by a finger or an input device. A method for controlling an optical touch device includes: emitting a linear light; providing a light guiding module, converting at least a portion of the linear light into a planar light, and guiding to an optical information extraction position, wherein the light guiding The module has a slope opposite to the optical information extraction position, and the slope has a relative angle with one of the working surfaces of the optical information extraction position, such that at least a portion of the linear light penetrates the slope and is converted into the plane After the light is directed to the optical information extraction position, and a portion of the planar light is reflected from the optical information extraction position to the slope, and the portion of the planar light is partially reflected to the light guide module by the slope a lateral side; causing the light guiding module to generate optical information according to light transmitted or reflected from the optical information extraction position, wherein the optical information is related to movement of an input device; and sensing the light guiding module The optical information is generated, and the electronic signal is generated according to the optical information; wherein the light guiding module is integrated with a lens module, and the lens module includes a first An optical lens interposed between the extracted position information to the light guide module, and a second lens interposed between the light guide module and the sensing of the optical information. The control method of claim 12, wherein the light guiding module has a trapezoidal cross section, and the linear light is infrared light. The control method of claim 13, further comprising: generating a feedback signal according to the optical information, and feeding back the brightness of the infrared light. The control method of claim 12, further comprising: controlling, according to the electronic signal, a cursor on the display optical information extraction position. The control method of claim 12, further comprising: generating three-dimensional information according to the electronic signal. The control method of claim 12, further comprising: moving the optical information extraction position of the light guiding module with an object at least partially reflective material. The control method of claim 12, wherein at least a majority of the area of the optical information extraction location is obscured by a finger or an input device.