TWI416391B - Infrared type handwriting input apparatus and scanning method - Google Patents

Abstract

An infrared type handwriting input apparatus and scanning method are disclosed. The input apparatus comprises a plurality of light emitters and a plurality of light receivers aligned along one side of a sensing area of the input apparatus, a control device and a signal processing device. The control device controls the light emitters to emit light and to control the light receivers to receive the light reflected from a pointer in the sensing area. The signal processing device processes the signals generated from the light receivers and transmits the processed signals to the control device.

Description

Infrared input device and position scanning method

The present invention relates to an input device and a position scanning method, and more particularly to a low-cost infrared input device and a position scanning method.

A device that inputs commands or information by touch, such as a display screen with a touch function, can accurately position the touch point within the effective sensing distance of the touch. There are many ways to detect the position of the touch point on the screen. One of them is to place the light emitting module and the light sensing module at the corner of the touch screen at the same time. The light emitting module emits a beam, and when the emitted beam hits To the indicator object (user's finger, pen or other object), such that part of the light beam is reflected back to a part of the sensing component of the light sensing module, and the sensing component of the light sensing module senses the indicator touch The position of the point reflected beam determines the corresponding angle of the indicator touch point. The position coordinates of the touch point can be calculated by using the triangular geometry principle by the angles of the indicator touch point and the light sensing module. The advantage of this method of detecting the position of the touch point is that sufficient resolution accuracy can be achieved with only a small number of components. However, the method for detecting the position of the touch point is to detect the change of the light sensing signal by scanning all the light sensing elements, but since the movement of the touch point is usually a continuous movement rather than a large distance, Therefore, it is repeated for all light sensing elements. Scanning is not an efficient way to scan, but it also slows down the touch response.

Another method for detecting the position of the touch point is to place the light emitting module and the light sensing module in opposite positions, and use a finger or a pen to block the light at the touch point to determine the detection. User finger touch point location. Such a technique for detecting touch point position can be used for a device of a large-sized sensing area, but the resolution depends on the number of light-emitting modules and light-sensing modules. U.S. Patent Nos. 3,764, 813, 4,928, 094, 5, 162, 783, and 6,677, 934 disclose prior art infrared light-emitting diode (LED) input technology and input devices. The disclosed input devices place an infrared light-emitting diode, that is, a transmitting end. One side of the sensing area is disposed on the opposite side of the sensing area, and the user's finger or pen is used to block the light beam traveling at the touch point to determine the user's finger. Touch point location. The resolution of the touch input technology as described above depends on the number of light emitting modules and light sensing modules. In order to have a certain resolution and completely cover the touch sensing area, the light emitting must be densely arranged on all four sides of the sensing area. And the light sensor, which not only increases the number of parts, but also increases the difficulty and cost of product assembly. Higher resolution requires more light-emitting modules and light-sensing modules to be used, which increases cost and complicates signal processing.

In view of the above disadvantages of the conventional input device and the position scanning method, the present invention provides an infrared input device and a position scanning method to reduce the number of parts and reduce the cost.

An object of the present invention is to provide an input device and a position scanning method, in which a light emitter and a light sensor are disposed on one side of a sensing area to reduce the number of parts and reduce the cost.

In accordance with the above objects, the present invention provides an input device comprising a plurality of light emitters and a plurality of light sensors on the same side of the sensing region of the input device, a control element and a signal processing component. The control element controls the light emitter to emit a beam of light and controls the light sensor to receive a beam of light reflected from an indicator in the sensing region. The signal processing component processes the photo-sensing signal generated by the photo sensor and transmits the processed photo-sensing signal to the control component.

According to the above object, the present invention provides a position scanning method for an input device, the input device comprising a control element and a plurality of light emitters and a plurality of light sensors on the same side of the sensing area of the input device, the control element is controlled The light emitter emits a beam of light and controls the light sensor to receive a beam of light reflected from an indicator in the sensing region. The position scanning method of the input device includes the following steps. First, the control element controls a light emitter to emit light into the sensing region. The control element then turns on all of the light sensors in sequence to receive the light beam reflected from the indicator. Repeat the above steps until all of the light emitters have emitted a beam of light. Comparing the light sensing signal intensity values received by the light sensor to determine the approximate position of the indicator in the Y-axis direction of the sensing region. The control element then controls at least one of the light emitters located in the region where the intensity of the optically inductive signal is strong to emit a light beam. The control element then turns on the light sensor to receive the light beam reflected from the indicator. Then, the light sensing signal intensity value received by the light sensor is compared to determine the Y axis coordinate of the indicator in the sensing area. Finally, the X-axis coordinate of the index is calculated by using the distance between the Y-axis coordinate of the indicator and the two adjacent photosensors closest to the Y-axis coordinate of the indicator.

101‧‧‧Sensing area

102‧‧‧Control elements

104‧‧‧Signal Processing Components

106‧‧‧Multiplexer

108‧‧‧Multiplexer

110‧‧‧Light emitter

112‧‧‧Light sensor

The first figure shows a basic conceptual diagram of an input device according to an embodiment of the present invention.

The second figure shows a schematic diagram of signal transmission and reception of an input device according to an embodiment of the invention.

The third figure shows the calculation method of the position coordinates of the indicator object according to an embodiment of the present invention.

Some embodiments of the invention are described in detail below. However, the present invention may be widely practiced in other embodiments than the following description, and the scope of the present invention is not limited by the examples, which are subject to the scope of the following patents. Further, in order to provide a clearer description and a better understanding of the present invention, the various parts of the drawings are not drawn according to their relative dimensions, and some dimensions have been exaggerated compared to other related dimensions; the irrelevant details are not fully drawn. Out, in order to make the schema simple.

The first figure shows a basic conceptual diagram of an input device according to an embodiment of the present invention. An indicator in the sensing area 101, such as a user's finger or stylus, is emitted by the light emitter 110 on one side of the sensing area 101 into the sensing area 101 when the light is incident. The light beam directed at the indicator, such as the user's finger or pen, is blocked and reflected back to the light sensor 112, and the nearest light sensor 112 can produce the highest intensity light sensing signal, which is not blocked by the indicator. The broken light beam is not reflected, the light sensor 112 does not generate a light sensing signal or only generates a weak light sensing signal, and the light sensor 112 of a specific angle is reflected by the index and produces the highest intensity. The optical sensing signal is processed by the signal processing component 104 to obtain a complete signal intensity distribution curve. After combining the result of the signal distribution curve with the algorithm, the position coordinates of the pointer of the indicator can be calculated. That is to say, based on the change of the optical sensing signal and the calculation of the algorithm, the position of the indicator in the sensing area 101 can be derived. The position of the light emitter 110 and the light sensor 112 and The arrangement is preferably arranged in an interleaved manner, but is not limited thereto. The light emitters 110 are arranged in a line, and each of the light emitters 110 is controlled by a control element 102 through a switch of a multiplexer 106. Each of the photo sensors 112 is also arranged in a line and is controlled by a control element 102 through a switch of a multiplexer 108. Control element 102 includes a microcontroller (MCU), but is not limited to a microcontroller. The light emitter 110 includes an infrared light emitting diode (LED), but is not limited to an infrared light emitting diode. The photo sensor 112 includes a photoelectrically-coupled element (CMOS Senosr) such as a charge coupled device (CCD Senosr) or a complementary metal oxide semiconductor, but is not limited to a charge coupled element or a complementary metal-oxygen semiconductor element, if the light emitter 110 When an infrared light emitting diode (LED) is used, the light sensor 112 can be replaced with an infrared sensor (Infrared Red Sensor). Each of the light emitters 110 corresponds to each switch of the multiplexer 106, and the control element 102 issues a control signal according to the firmware programming to determine the mode in which the light emitter 110 is turned on or scanned. Each of the photo sensors 112 corresponds to each switch of the multiplexer 108, and the control unit 102 sends a control signal according to the firmware setting to determine the mode in which the photo sensor 112 is turned on or scanned. The photo sensor 112 is configured according to the photo sensor 112. The control signal from the control component 102 is turned on to receive the light beam emitted by the light emitter 110 and reflected back by the indicator object, such as the user's finger. The light sensor 112 receives the light beam to generate a light sensing signal, and transmits the light sensing signal to the signal. Processing component 104. The optical sensing signal processed by the signal processing component 104 is transmitted back to the control component 102 for calculation of the coordinate position of the pointer within the sensing region. What is described herein is a schematic diagram of the basic concept of the touch input device shown in the first figure, and therefore parts that are less relevant to the main features of the present invention are omitted. The parts omitted in the input device in this embodiment can be implemented by any related art, and any one skilled in the art can implement the present invention according to the general technical level. The sensing area 101 of the touch input device of the present invention is a kind The surface of the touch input function can be combined with the display screen and the writing surface. For example, when the screen is combined, a sensing area of a touch panel is formed, and when combined with the whiteboard surface, a touch type electronic body is formed. The sensing area of an electronic white board, etc., but its application is not limited to the two types of touch screens and touch electronic whiteboards, and all other equivalent changes or modifications that do not depart from the spirit of the invention are covered. Within the scope of the present invention. The touch screen includes a touch flat display screen, such as a liquid crystal display screen, a plasma display screen, an internal projection display screen, etc., and does not exclude a cathode ray tube screen. The above-described elements of the embodiments of the present invention are intended to be illustrative and not limiting, and various equivalents and modifications may be made without departing from the spirit and scope of the invention.

The second figure shows a schematic diagram of signal transmission and reception of an input device according to an embodiment of the invention. The figure shows that a light emitter 110 emitted by the pair of indicators enters the sensing area 101, and the light blocked by the user's finger and reflected back is received by all the light sensors 112 and generates a light sensing signal. The intensity of the light sensing signal is inversely proportional to the distance between the light sensor 112 and the index of the indicator or the user, and the distance between the light sensor 112 and the index of the indicator or the user's finger is greater. The light sensing signal generated by the detector 112 is weaker. The closer the distance between the light sensor 112 and the index of the indicator or the user's finger, the stronger the light sensing signal generated by the light sensor 112, and thus the distribution of the light sensing signal can be generated. Since the light emitter 110 and the light sensor 112 are arranged along the Y axis, the light sensing signals are distributed along the Y axis, and the Y-axis coordinates of the index or the user's finger can be obtained. In the second figure, the light sensor 112 closest to the finger or the user's finger has the strongest light-sensing signal, and the light-sensing signal intensity distribution of the light sensor 112 is gradually attenuated from the center to the sides. The second figure shows the light-induced signal intensity distribution of the light sensor 112 generated by the light emitter 110 of the indicator, and the light of the light sensor 112 generated by the light emitter 110 of the other non-aligned indicator. Induction The intensity distribution is different, but the light sensor 112 closest to the indicator or the user's finger still has the strongest light sensing signal.

As shown in the first figure, in order to detect whether an indicator appears in the sensing area of the input device, the control element 102 must control the light emitter 110 to emit a light beam, and the control element must simultaneously control the light sensor 112 to receive the light sensor 112. The indicator object, such as the beam reflected back by the user's finger, calculates the position of the indicator within the sensing area. The control component 102 first issues a control signal to sequentially switch the switches by the multiplexer 106 to sequentially turn on the light emitter 110 to emit a light beam. The control element 102 sends a control signal to sequentially switch the switch by the multiplexer 108 to turn on the photo sensor 112. In one embodiment, the full area scanning of the sensing area is controlled by the control element 102 to control the multiplexer 106 to turn on a light emitter 110 to emit a light beam, and then the control unit 102 controls the multiplexer 108 to turn on all of the light sensing one by one. The device 112 receives the light beam that may be reflected back after being transmitted by the first light emitter 110. The control element 102 then controls the multiplexer 106 to turn on the second light emitter 110 to emit a light beam, and then the control unit 102 controls the multiplexer 108 to turn on all of the light sensors 112 one by one to receive the second light emitter 110 after the launch. The reflected light beam is reflected and then repeated until the last light emitter 110 emits a light beam and all of the light sensors 112 receive a light beam that may be reflected back. If the indicator appears in the sensing area of the input device, the light sensor 112 receives the light beams that are sequentially transmitted from the light emitters 110 and are reflected back from the indicator, because each of the light emitters 110 and the light sensor 112 The distance from the indicator is different, so the distribution of the intensity of the photo-sensing signal along the Y-axis is generated. Comparing the photo-sensing signal intensity values, it can be inferred that the index object is located at approximately the Y-axis direction in the sensing region 101.

When it is determined that the indicator is located at an approximate position in the Y direction in the sensing area 101, a partial area scanning is performed on the sensing area. The control component 102 controls the multiplexer 106 to turn on the light emitter 110 with the strongest intensity of the light-sensing signal to emit a light beam, and then the control component 102 controls the multiplexer 108 to turn on all the light sensors 112 to receive the light reflector 110. The beam of light returned. Comparing the intensity values of the photo-sensing signals according to the intensity distribution of the photo-sensing signals of all the photo sensors 112, extracting the signal intensity values of the photo-sensing signal intensity and the second-order optical sensor 112, thereby using the three lights The actual position adjacent distance of the induced signal strength and the calculation of the algorithm can calculate the exact Y coordinate of the indicator in the sensing area 101. Calculating the Y coordinate of the indicator in the sensing region 101 can use the following formula: Y _R ={(Y _1st -Y _2nd )/[(Y _1st -Y _2nd )+(Y _1st -Y _3rd )]}×( L×K _R )

Y=(n-1)×(L×K _R )+Y _R

Wherein, if the distance between the two photosensors 112 is L inches, and the resolution per inch is K _R , Y _1st is the signal intensity value of the photo sensor 112 having the strongest intensity of the photo-sensing signal, Y _2nd is the signal intensity value of the light sensor 112 having the second strongest intensity of the light sensing signal, _Y3rd is the signal intensity value of the light sensor 112 having the third strongest intensity of the light sensing signal, and Y _R is the index of the indicator on the Y axis. Relative to the relative address of the strongest photosensor 112, Y is the absolute address of the indicator on the Y-axis.

In order to calculate the X coordinate of the position of the indicator in the sensing area 101, the calculation method shown in the third figure can be utilized. If the photo sensor N is the photo sensor with the strongest intensity of the photo-sensing signal, the Y-coordinate of the position where the index is located in the sensing area 101 and the second-strongest light closest to the Y coordinate are known. the sensor 112 such as an optical sensor coordinate Y coordinate value N + 1, Y coordinate thereof is obtained indicator and the light sensor are N and N + Y direction, the light sensor 1 and the distance Y ₁ Y ₂ . That is to say, the length of Y ₁ plus Y ₂ is exactly L inches. As previously mentioned, the closer the distance between the light sensor 112 and the index of the indicator or the user's finger, the stronger the light sensing signal generated by the light sensor 112, so that the light sensor N and The photo-sensing signal intensity value received by the photo sensor N+1 can obtain the linear distances L ₁ and L _{2 of the} index in the sensing region 101 from the photo sensor N and N+1, and the adjacent optical sensitivities The distance between the detectors is L inches, and X ₁ and X ₂ can be calculated by knowing Y ₁ and L ₁ and Y ₂ and L ₂ , respectively. Finally, the X absolute coordinate of the position of the indicator in the sensing area 101 can be calculated by the following formula: X ₁ ² = L ₁ ^{2 -} Y ₁ ²

X ₂ ² = L ₂ ^{2 -} Y ₂ ²

X=(X ₁ +X ₂ )/2

The input device and the position scanning method of the present invention configure the light emitter and the light sensor on one side of the sensing area. In one embodiment, the light emitter and the light sensor are staggered to save the number of parts used. cut costs. The touch position scanning method is performed by sequential scanning and partial area scanning of the entire area of the light sensor, and can be achieved by writing the firmware of the microcontroller. The invention is based on the first point-by-point scan to find the light sensor with the largest light sensing signal, and in the subsequent scanning, the full light sensor scanning is not performed, but only the partial area scanning is performed. Partial scanning scans only a certain range of light sensors with the largest sensing signal, such as front and rear three light sensors. When the indicator moves, part of the scanning will detect the light with the largest sensing signal. The sensor is moved relative to the indicator. Therefore, it is only necessary to update a certain range of light sensors to be scanned before and after scanning, and to improve the speed of scanning and tracking indicators.

The embodiments described above are merely illustrative of the technical spirit and features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the contents of the present invention and to implement them. The scope of the invention is defined by the scope of the invention, which is intended to be included within the scope of the invention.

101‧‧‧Sensing area

102‧‧‧Control elements

104‧‧‧Signal Processing Components

106‧‧‧Multiplexer

108‧‧‧Multiplexer

110‧‧‧Light emitter

112‧‧‧Light sensor

Claims (12)

An input device comprising: a plurality of light emitters interleaved with a plurality of light sensors on the same side of a sensing area of the input device; a control element that controls the plurality of light emitters Transmitting a light beam and controlling the plurality of light sensors to receive a light beam reflected from an indicator in the sensing area; and a signal processing component, the signal processing component processing the light sensing signal generated by the light sensor to generate a signal The intensity distribution curve is transmitted to the control component, and the control component calculates the coordinates of the indicator according to the signal intensity distribution curve and the positions of the plurality of photo sensors. The input device of claim 1, wherein the light emitter comprises an infrared light emitting diode. The input device of claim 1, wherein the photo sensor comprises one of a charge coupled device or an infrared sensor or a complementary MOS device. The input device of claim 1, wherein the control element controls the light emitter and the light sensor respectively through at least one multiplexer. The input device of claim 1, wherein the sensing area of the input device comprises a sensing area of an electronic white board. The input device of claim 1, wherein the sensing area of the input device comprises a touch liquid crystal display screen sensing area, and a touch plasma display screen sensing area. One of the domain, the touch-in-projection display screen sensing area, and the touch cathode ray tube sensing area. A position scanning method for an input device, the input device comprising a plurality of light emitters interspersed with a plurality of light sensors on a same side of a sensing area of the input device and a control element, the control element controlling the light emission Transmitting a beam of light and controlling the light sensor to receive a beam of light reflected from an indicator in the sensing region, the position scanning method comprising: (a) controlling the light emitting device to emit light into the sensing region (b) the control element sequentially turns on all of the light sensors to receive the light beam reflected from the indicator; (c) repeats (a) to (b) until all of the light emitters have emitted a light beam; Comparing the optical sensor signal intensity value received by the photo sensor to determine an approximate position of the index object in the Y-axis direction of the sensing region; (e) the control component controls at least one of the regions with the strongest intensity of the photo-sensing signal The light emitter emits a light beam; (f) the control element turns on the light sensor to receive a light beam reflected from the indicator; (g) compares the light sensing signal intensity value received by the light sensor to determine the indicator Sense of presence The Y-axis coordinate in the measurement area; and (h) calculating the X-axis coordinate of the indicator by using the Y-axis coordinate of the indicator and the distance between the adjacent optical sensors closest to the Y-axis coordinate distance of the index object . The position scanning method of the input device according to claim 7, wherein the light emitter comprises an infrared light emitting diode. The position scanning method of the input device according to claim 7, wherein the photo sensor comprises one of a charge coupled device or an infrared ray sensor or a complementary MOS device. The position scanning method of the input device according to claim 7, wherein the control element controls the three light emitters located at the region where the intensity of the optical signal is strongest to emit a light beam. The method of scanning a position of an input device according to claim 7, wherein the sensing area of the input device comprises a sensing area of an electronic white board. The method for scanning a position of an input device according to claim 7, wherein the sensing area of the input device comprises a touch liquid crystal display screen sensing area, a touch plasma display screen sensing area, and a touch internal projection type. One of the screen sensing area and the touch cathode ray tube sensing area is displayed.