Touch detection system

Abstract

This system provides a "touch detection system" that suppresses false touch detection by touch sensors installed below the display. [Solution] Four touch sensors TS1-TS4 and seven proximity sensors IPS1-IPS7 are arranged side by side near the bottom of the display 21. The seven proximity sensors IPS1-IPS7 emit infrared light at a predetermined angle, diagonally towards the front and upward of the display 21, and detect the intensity of the reflected infrared light. The approach of a hand attempting to operate the touch sensor is detected only when a reflected light intensity of Thi or higher is detected in any of the touch sensors IPSi, and a reflected light intensity of a predetermined level or higher is not detected in either of the two adjacent touch sensors (IPSi-2 or IPSi+2) (or only one if only one exists).

Description

Technical Field

[0001] The present invention relates to a technique for suppressing false detection of a touch sensor.

Background Art

[0002] As a technique for suppressing false detection of a touch sensor, a proximity sensor for detecting the approach of an operator to a capacitive touch panel is provided, the sensitivity of the touch panel is lowered when the operator is not approaching, and the sensitivity of the touch panel is increased when the operator is approaching the touch panel, thereby suppressing false detection of a touch on the touch panel due to noise or the like not caused by the operator (for example, Patent Document 1).

[0003] Also, as a technique related to the present invention, a plurality of LEDs arranged along the lower side of the display and irradiating infrared light obliquely upward in front of the display are lit, and a plurality of photodiodes arranged along the lower side of the display detect the reflected light of the infrared light by the operator, and a technique for detecting the approach of the operator to the display surface from the intensity of the reflected light is known (for example, Patent Document 2).

[0004] Also, as a technique related to the present invention, a touch panel in which electrodes are arranged linearly (one-dimensionally) and capable of receiving a slide operation in which a finger touched in the electrode arrangement direction is moved is known (for example, Patent Document 3).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] In in-vehicle infotainment (IVI) and other in-vehicle information systems, the display unit, which is responsible for display output and operation reception interfaces for the user, is often mounted on the car's dashboard or the top of the dashboard.

[0007] Furthermore, such display units sometimes utilize a unit that includes a display with a touch panel and a capacitive touch sensor positioned along the bottom edge of the display. Therefore, in order to suppress false detections due to noise in such touch sensors, it is conceivable to apply the above-mentioned technology and arrange multiple LEDs that emit infrared light diagonally upward in front of the display along the bottom edge of the display to detect the approach of the operator from the reflected infrared light, and to reduce the sensitivity of the touch panel when the operator is not approaching and increase the sensitivity of the touch panel when the operator is approaching the touch panel, thereby suppressing false detections of touches on the touch panel due to noise, etc.

[0008] However, this approach can lead to problems such as the following when a display unit is mounted on the top of the dashboard. In other words, if an object such as a charm or accessory hanging from the rearview mirror of a car hangs down in front of the display unit, the system may mistakenly detect the operator's approach to this object, increasing the sensitivity of the touch panel and making it impossible to suppress false touch detections caused by noise or other factors.

[0009] While it is possible to pre-set detection characteristics through calibration to avoid detecting stationary, fixed objects, objects suspended from the rearview mirror sway due to the vibrations of the vehicle, making it impossible to pre-set such detection characteristics through calibration.

[0010] Therefore, the present invention aims to properly suppress false touch detection by the touch sensor even when there is an object installed in front of and above it. [Means for solving the problem]

[0011] To achieve the above objectives, the present invention provides a touch detection system comprising a display and a touch sensor disposed on the lower side of the lower edge of the display surface of the display, comprising: three or more light sources arranged side by side in the left-right direction of the display on the lower side of the lower edge of the display surface of the display, which emit invisible light upward toward the front of the display surface; light detection means for each light source, which detects the reflected invisible light emitted by the light source; touch detection means for detecting a touch of the touch sensor with a set detection sensitivity; and detection sensitivity setting means for setting the detection sensitivity of the touch detection means. Here, the detection sensitivity setting means determines whether detection is present when a predetermined condition is met, with i being the order of arrangement of the light sources along the left-right direction, and sets the detection sensitivity of the touch detection means to the first sensitivity, and otherwise sets the detection sensitivity of the touch detection means to a second sensitivity which is lower than the first sensitivity. Furthermore, the predetermined conditions are necessary for the intensity of reflected light from the i-th light source detected by the light detection means to be greater than a predetermined threshold, and are not met if the reference reflected light intensity is greater than a level determined from a predetermined standard. The reference reflected light intensity is the greater of the intensity of reflected light from the i+A-th light source detected by the light detection means and the intensity of reflected light from the iA-th light source, where A is an integer of 1 or more. If both the i+A-th light source and the iA-th light source exist, the reference reflected light intensity is the intensity of reflected light from the existing light source detected by the light detection means.

[0012] Here, the touch detection system may use the reference reflected light intensity as the sum of the intensity of reflected light from the i+A-th light source and the intensity of reflected light from the iA-th light source detected by the light detection means, where A is an integer of 1 or more, if both the i+A-th light source and the iA-th light source are present, or as the intensity of reflected light from the present light source detected by the light detection means if only one of the i+A-th light source and the iA-th light source is present.

[0013] Furthermore, the touch detection system may be configured such that, for any i, the detection sensitivity setting means determines that a detection has occurred if the value obtained by subtracting the reference reflected light intensity from the intensity of the reflected light of the i-th light source detected by the light detection means is greater than a predetermined threshold, and sets the detection sensitivity of the touch detection means to the first sensitivity; otherwise, it sets the detection sensitivity of the touch detection means to the second sensitivity.

[0014] Alternatively, the touch detection system may be configured such that, for any i, the detection sensitivity setting means determines that a detection has occurred if the intensity of the reflected light from the i-th light source detected by the light detection means is greater than a predetermined threshold and the reference reflected light intensity is not greater than a predetermined value, and sets the detection sensitivity of the touch detection means to the first sensitivity; otherwise, it sets the detection sensitivity of the touch detection means to the second sensitivity.

[0015] Alternatively, the touch detection system may be configured such that, for any i, the detection sensitivity setting means determines that a detection has occurred when the intensity of the reflected light from the i-th light source detected by the light detection means is greater than a threshold set to increase as the reference reflected light intensity increases, and sets the detection sensitivity of the touch detection means to the first sensitivity; otherwise, it sets the detection sensitivity of the touch detection means to the second sensitivity.

[0016] In the touch detection system described above, A=2 may be set. Furthermore, to address the aforementioned problems, the present invention provides a touch detection system comprising a display and a touch sensor positioned below the lower edge of the display surface of the display, comprising: three or more light sources arranged side by side in the left-right direction of the display below the lower edge of the display surface of the display, which emit invisible light toward the front of the display surface; light detection means for each light source, which detects the reflected invisible light emitted by the light source; touch detection means for detecting a touch of the touch sensor with a set detection sensitivity; and detection sensitivity setting means for setting the detection sensitivity of the touch detection means. The detection sensitivity setting means comprises a first detection means, a second detection means, and a detection determination unit. The first detection means determines detection is present for any i, where i is the order of the light sources arranged along the left-right direction, if a predetermined condition is met. The predetermined condition is necessary for the intensity of reflected light from the i-th light source detected by the light detection means to be greater than a predetermined threshold, and the condition is not met if the reference reflected light intensity is greater than a level determined from a predetermined standard. The reference reflected light intensity is the greater of the intensity of reflected light from the i+A-th light source detected by the light detection means and the intensity of reflected light from the iA-th light source, where A is an integer of 1 or more. If both the i+A-th light source and the iA-th light source exist, the reference reflected light intensity is the intensity of reflected light from the existing light source detected by the light detection means. The second detection means determines detection is present for any i, where i is the order of the light sources arranged along the left-right direction, if the intensity of reflected light from the i-th light source detected by the light detection means is greater than the predetermined threshold and a predetermined second threshold. The detection determination unit then sets the detection sensitivity of the touch detection means to the first sensitivity if at least one of the first detection means and the second detection means determines that detection is present, and sets the detection sensitivity of the touch detection means to a second sensitivity which is lower than the first sensitivity in other cases.

[0017] Here, the touch detection system may use the reference reflected light intensity as the sum of the intensity of reflected light from the i+A-th light source and the intensity of reflected light from the iA-th light source detected by the light detection means, where A is an integer of 1 or more, if both the i+A-th light source and the iA-th light source are present, or as the intensity of reflected light from the present light source detected by the light detection means if only one of the i+A-th light source and the iA-th light source is present.

[0018] Furthermore, to address the aforementioned problems, the present invention provides a touch detection system comprising a display and a touch sensor disposed below the lower edge of the display surface of the display, comprising: a plurality of light sources arranged side by side in the left-right direction of the display below the lower edge of the display surface of the display, which emit invisible light toward the front of the display surface; a light detection means for each of the light sources that detects the reflected invisible light emitted by the light source; a touch detection means that detects a touch of the touch sensor with a set detection sensitivity; and a detection sensitivity setting means that sets the detection sensitivity of the touch detection means. Here, the detection sensitivity setting means determines that a detection has occurred for any i, if the magnitude of the signal obtained by attenuating the frequency component of the vibration frequency band of an object that may be installed hanging in front of the upper part of the display surface of the display is greater than a threshold, and sets the detection sensitivity of the touch detection means to the first sensitivity; and otherwise sets the detection sensitivity of the touch detection means to a second sensitivity which is lower than the first sensitivity.

[0019] In the touch detection system described above, the display may be positioned on the top of the car's dashboard. According to the touch detection system as described above, from the installation object hanging down to the front of the upper part of the display, more reflected light of continuously arranged light sources can be obtained than the hand of the operator approaching the touch sensor at the lower part of the display. Also, since the suspended installation object swings like a pendulum, by utilizing the fact that the reflected light has a frequency within a certain range, the approach of the operator's hand to the touch sensor can be discriminated and detected from the installation object suspended to the upper front surface of the display.

Effect of the Invention

[0020] As described above, according to the present invention, even when there is an installation object in the front upper direction, it is possible to appropriately suppress the erroneous detection of the touch of the touch sensor.

Brief Description of the Drawings

[0021] [Figure 1] It is a block diagram showing the configuration of an information processing system according to an embodiment of the present invention. [Figure 2] It is a diagram showing a display unit according to an embodiment of the present invention and its arrangement. [Figure 3] It is a diagram showing the positional relationship between a display unit and a nearby object according to an embodiment of the present invention. [Figure 4] It is a diagram showing the configuration of a display surface approach detection unit according to an embodiment of the present invention. [Figure 5] It is a diagram showing the configuration of a lower region approach detection unit according to an embodiment of the present invention. [Figure 6] It is a diagram showing another configuration example of a lower region approach detection unit according to an embodiment of the present invention. [Figure 7] It is a diagram showing another configuration example of a lower region approach detection unit according to an embodiment of the present invention. [Figure 8] It is a diagram showing another configuration example of a lower region approach detection unit according to an embodiment of the present invention. [Figure 9] It is a diagram showing another configuration example of a lower region approach detection unit according to an embodiment of the present invention. [Figure 10] It is a diagram showing an aspect of sensitivity adjustment in a touch detection unit according to an embodiment of the present invention. [Figure 11] This figure shows another example configuration of the information processing system according to an embodiment of the present invention. [Figure 12] This figure shows another example configuration of the information processing system according to an embodiment of the present invention. [Modes for carrying out the invention]

[0022] Embodiments of the present invention will be described below. Figure 1 shows the configuration of the information processing system according to this embodiment. The information processing system is a system installed in an automobile and includes a data processing unit 1 that executes applications such as car navigation applications, media player applications, and control applications for automobile equipment such as air conditioners, a display unit 2 that functions as a peripheral device to the data processing unit 1, and other peripheral devices 3.

[0023] The display unit 2 includes a display 21 with a touch panel used by the data processing device 1 for displaying images and inputting coordinates, a touch sensor unit 22, a touch detection unit 23 for detecting touches from the touch sensor, a proximity sensor unit 24, and a proximity detection unit 25. The touch sensor unit 22 is equipped with four touch sensors, TS1-TS4. Each touch sensor is a capacitive touch sensor, for example, a one-dimensional touch panel. The proximity sensor unit 24 is equipped with seven proximity sensors, IPS1 to IPS7. Each proximity sensor includes an infrared LED that emits infrared light and a photodiode (PD) that detects light in a wavelength range that includes the wavelength of the infrared light emitted by the infrared LED. Here, as shown in Figure 2a1, which is a front view of the display unit 2, and Figure 2a2, which is a side view of the display unit 2, the four touch sensors TS1-TS4 are arranged side by side near the bottom of the display 21. Furthermore, the seven proximity sensors IPS1-IPS7 are arranged in the area below the placement area of ​​the four touch sensors TS1-TS4, with spacing between them, in the order of IPS1, IPS2, IPS3, IPS4, IPS5, IPS6, and IPS7 from left to right. Furthermore, as shown in the front view of Figure 2b1 and the side view of Figure 2b2, the seven proximity sensors IPS1-IPS7 emit infrared light diagonally upward toward the front of the display 21 at a predetermined irradiation angle, and detect the intensity of the reflected infrared light. Here, the emission of infrared light and the detection of reflected light by the seven proximity sensors IPS1-IPS7 are performed sequentially and cyclically for each proximity sensor.

[0024] The display unit 2 is then positioned on the top of the dashboard, as shown in Figure 2c. The data processing unit 1 and peripheral devices 3 may be integrated with the display unit 2. Returning to Figure 1, the touch detection unit 23 detects the touch and touch position of each touch sensor TS1-TS4. Furthermore, the proximity detection unit 25 includes a display surface proximity detection unit 251 that uses seven proximity sensors IPS1-IPS7 to detect the approach of the operator's hand to the display surface (touch panel) of the display, and a lower area proximity detection unit 252 that uses seven proximity sensors IPS1-IPS7 to detect the approach of the operator's hand to the lower area, which is the area below the display 21.

[0025] Next, Figures 3a, b1, and b2 show the relationship between the display unit 2, which is positioned on the top of the dashboard as described above, and the items such as amulets and accessories that are suspended from the rearview mirror of the car. As shown in Figure 3a, the installation object OBJ suspended from the rearview mirror of a car may hang down to the upper front of the display 21 of the display unit 2. In this case, as shown in the front view in Figure 3b1 and the side view in Figure 3b2, the installation object OBJ is illuminated by infrared light emitted by multiple of the seven proximity sensors IPS1-IPS7, and the reflected light is detected.

[0026] In this embodiment, the arrangement and illumination angle of each proximity sensor are set so that the infrared light from four or more proximity sensors illuminates an object located in front of the upper part of the display 21. On the other hand, as shown in the front view of Figure 3c1 and the side view of Figure 3c2, when an operator extends one finger to bring their hand closer to the underside of the display 21 in order to operate the touch sensors TS1-TS4, the hand is positioned closer to the proximity sensors. As a result, it is illuminated by infrared light from fewer proximity sensors than the number of proximity sensors illuminating an object in front of the top of the display 21, and the reflected light is detected.

[0027] In this embodiment, the arrangement and illumination angle of each proximity sensor are set so that the infrared light from two or fewer proximity sensors illuminates the hand that the operator brings close to the lower side of the display 21 with one finger extended. Based on the above, we will now describe the display surface proximity detection unit 251, which uses the seven proximity sensors IPS1-IPS7 to detect the approach of the operator's hand to the display surface (touch panel), and the lower area proximity detection unit 252, which uses the seven proximity sensors IPS1-IPS7 to detect the approach of the operator's hand to the lower area of ​​the display 21.

[0028] First, Figure 4 shows the configuration of the display surface proximity detection unit 251 using a logic circuit equivalent to that configuration. As shown in the figure, the display surface proximity detection unit 251 has seven comparators CP1-CP7 and a logical OR circuit. Li (i=1, 2, 3, 4, 5, 6, 7) is the reflected light intensity detected by IPSi. CPi compares Li with a preset threshold Thi, outputting 1 if Li is greater, and 0 otherwise. The OR circuit outputs 1 when any of CP1-CP7 outputs 1, and 0 when all of CP1-CP7 output 0. A 1 output from the OR circuit indicates a hand approaching the display surface, while a 0 output indicates no approach.

[0029] Therefore, when any of Li (i=1, 2, 3, 4, 5, 6, 7) exceeds the corresponding threshold Thi, the approach of a hand to the display surface is detected. It is preferable to set the threshold Thi to a value predetermined as the Li value when a hand approaches a predetermined distance or more from the position where infrared light from the IPSi in front of the display surface is irradiated. However, the threshold Thi may be set to the same value for all positions. Furthermore, the threshold Thi is set to be greater than the intensity of reflected light from the installed object OB located in front of the upper part of the display 21, as shown in Figure 3b1, so that the object OB is not detected as a hand approaching the display. Note that the closer the reflector is to the proximity sensor and the larger the size of the reflector, the greater the reflected light intensity. By setting the threshold Thi in this way, the approach of a hand to the front of the display surface can be detected without practical problems.

[0030] The display surface proximity detection unit 251 detects when a hand approaches the display surface and notifies the data processing device 1. Upon receiving notification of the approach of a hand to the display surface, the data processing device 1 performs predetermined processing such as switching the display screen of the display 21 or enlarging the display icons. Next, Figure 5 shows the configuration of the lower region approach detection unit 252 using a logic circuit equivalent to the said configuration. As shown in the figure, the lower region proximity detection unit 252 has seven comparators CP1-CP7, seven subtractors SB1-SB7, seven multipliers G1-G7, three selectors SL3-SL5, and an OR circuit. SLj(j=3, 4, 5) outputs the larger of Lj-2 and Lj+2, Gj amplifies the output of SLj by gain Aj, SBj subtracts the output of Gj from Lj, and CPj compares the output of SBj with a preset threshold Thj, outputting 1 if the output of SBj is larger, and 0 otherwise. Gk (k=1, 2) amplifies the output of Lk+2 by gain Ak, SBk subtracts the output of Gk from Lk, and CPk compares the output of SBk with a preset threshold Thk, outputting 1 if the output of SBk is greater, and 0 otherwise. Gm (m=6, 7) amplifies the output of Lm-2 by gain Am, SBm subtracts the output of Gm from Lm, and CPm compares the output of SBm with a preset threshold Thm, outputting 1 if the output of SBm is greater, and 0 otherwise. The OR gate outputs 1 when any of CP1-CP7 outputs 1, and 0 when all of CP1-CP7 output 0. When the output of the OR gate is 1, it indicates that a hand is approaching the lower region, which is the area near the touch sensor below the display 21, and when it is 0, it indicates that a hand is not approaching.

[0031] Therefore, the lower region proximity detection unit 252 detects the approach of a hand to the lower region when any of the Li (i=1, 2, 3, 4, 5, 6, 7) has a value obtained by multiplying the larger of Li+2 and L-2 (however, if Li+2 does not exist, the value of L-2 is used; if Li-2 does not exist, the value of L+2 is used) by a predetermined count Ai, and subtracting this value from Li, exceeds the corresponding threshold Thi.

[0032] As a result, approach of a hand to the lower area is detected only when a reflected light intensity of Thi or higher is detected in any of the touch sensors IPSi, and a reflected light intensity of a predetermined level or higher is not detected in either of the two adjacent touch sensors (IPSi-2 or IPSi+2) (or only one if only one exists).

[0033] Therefore, as shown in Figure 3b1, for an object OBJ located in front of the top of the display 21 and illuminated by infrared light from 4 or more proximity sensors, the detection of a hand in the downward area is not detected. On the other hand, as shown in Figure 3c1, the approach of a hand in the downward area is detected for an operator's hand brought close to the lower touch sensor of the display 21, which is illuminated by infrared light from 2 or fewer proximity sensors.

[0034] The gain Ai of Gi is a tuning coefficient, and an appropriate value is determined and set in advance through experiments or other means so that the approach of a hand to the lower region is not detected relative to the installed object OBJ in Figure 3b1, but the approach of a hand to the lower region is detected when the operator's hand is brought close to the lower touch sensor of the display 21.

[0035] Now, the function of the lower region proximity detection unit 252 may be realized by a configuration different from that shown in Figure 5. For example, the logic circuit equivalent to the lower region proximity detection unit 252 may be configured as shown in Figure 6. As shown in the figure, in this configuration, the lower region proximity detection unit 252 has seven comparators CP1-CP7, seven comparators CPD1-CPD7, seven AND circuits AND1-AND7, three selectors SL3-SL5, and an OR circuit. CPi(i=1, 2, 3, 4, 5, 6, 7) compares Li with a pre-set threshold Thi, outputting 1 if Li is greater, and 0 otherwise. SLj(j=3, 4, 5) outputs the larger of Lj-2 and Lj+2, and CPDj compares the output of SLj with a pre-set threshold ThDj, outputting 1 if the output of ThDj is larger, and 0 otherwise. CPDk(k=1, 2) compares the output of Lk+2 with the threshold ThDi, outputting 1 if ThDi is greater, and 0 otherwise. CPDm(m=6,7) compares the output of Lm-2 with the threshold ThDm, outputting 1 if the ThDm output is greater, and 0 otherwise. ANDi(i=1, 2, 3, 4, 5, 6, 7) outputs 1 when both CPi and CPDi outputs are 1, and 0 otherwise. The OR gate outputs 1 when any of AND1-AND7 outputs 1, and 0 when all of AND1-AND7 outputs 0. The output of a logical OR circuit is 1, which indicates that the hand is approaching the lower region, and 0, which indicates that it is not approaching. As a result, when the output of CPDi to the OR circuit is 0, the output of CPi is masked to 0. Therefore, approach of a hand to the lower area is detected only when a reflected light intensity of Thi or higher is detected in any of the touch sensors IPSi, and a reflected light intensity of a predetermined level or higher is not detected in either of the two adjacent touch sensors (IPSi-2 or IPSi+2) (or only one of them if only one exists).

[0036] Therefore, the configuration shown in Figure 6 can perform the same function as the lower region proximity detection unit 252 shown in Figure 5. The threshold ThDi is set in advance by determining, through experiments or other means, an appropriate value such that approach of a hand to the lower region is not detected relative to the installed object OBJ in Figure 3b1, but approach of a hand to the lower region is detected when the operator's hand is brought close to the lower touch sensor of the display 21. Alternatively, for example, the logic circuit equivalent to the lower region proximity detection unit 252 may be configured as shown in Figure 7. As shown in the figure, in this configuration, the lower region proximity detection unit 252 has seven comparators CP1-CP7, three selectors SL3-SL5, seven threshold control circuits ThCNT1-ThCNT7, and an OR circuit. CPi(i=1, 2, 3, 4, 5, 6, 7) compares Li with the threshold Thi input from ThCNTi, outputting 1 if Li is greater, and 0 otherwise. SLj(j=3, 4, 5) outputs the larger of Lj-2 and Lj+2, and ThCNTj controls the ThCNTj output to CPj so that it becomes larger as the output of SLj increases. ThCNTk(k=1, 2) controls the ThCNTk output to CPk in accordance with the output of Lk+2, such that the output of ThCNTk increases as Lk+2 increases. ThCNTm (m=6, 7) controls the ThCNTm output to CPm in accordance with the output of Lm-2, such that the larger Lm-2 is, the larger the ThCNTm output. The OR gate outputs 1 when any of CP1-ACP7 outputs 1, and 0 when all of CP1-CP7 outputs 0. The output of a logical OR circuit is 1, which indicates that the hand is approaching the lower region, and 0, which indicates that it is not approaching. As a result, the threshold Thi, which is compared with Li in CPi, increases when a reflected light intensity above a predetermined level is detected by both (or one of) the two adjacent touch sensors (IPSi-2 or IPSi+2), reducing the sensitivity of approach detection to the lower region in CPi. Therefore, the configuration shown in Figure 7 can perform the same function as the lower region approach detection unit 252 shown in Figure 5.

[0037] Alternatively, as shown in Figure 8a, when an operator extends their hand to operate a touch sensor, reflected light intensity may be detected by three or more touch sensors. In this case, considering that the configurations in Figures 5, 6, and 7 may not detect the approach of the hand to the lower region, the configuration of the lower region approach detection unit 252 may be as shown in Figure 8b.

[0038] As shown in the figure, in this configuration, the lower region proximity detection unit 252 includes a first detection block 2521, a second detection block 2522, and a logical OR circuit ORT. The first detection block 2521 has the same configuration as the lower region proximity detection unit 252 shown in Figures 5, 6, and 7. The second detection block 2522 has seven comparators CPE1-CPE7 and a logical OR circuit ORE. CPEi compares Li with a pre-set threshold ThEi and outputs 1 if Li is greater, and 0 otherwise. The OR circuit ORE outputs 1 if any of CPE1-CPE7 are outputting 1, and 0 if all of CPE1-CPE7 are outputting 0. The OR gate ORT outputs 1 when either the first detection block 2521 or the second detection block 2522 outputs 1, and outputs 0 when both outputs 0. The output of the OR gate ORT is 1 when it indicates that the hand is approaching the lower region, and 0 when it indicates that the hand is not approaching.

[0039] The threshold ThEi used in the second detection block 2522 is a value greater than the threshold Thi used in the first detection block 2521. As shown in Figure 8a, when an operator extends their hand to operate the touch sensor, the hand is close to the proximity sensor, and because the hand is extended, the reflected light intensity increases. Therefore, by pre-determining and setting an appropriate threshold ThEi such that the reflected light intensity of the installed object OBJ in Figure 3b1 does not exceed the threshold ThEi, and the reflected light intensity of the hand extended and brought close to the touch sensor on the lower side of the display 21 exceeds the threshold ThEi, it is possible to discriminate and detect a hand that is extending its hand to operate the touch sensor.

[0040] As a result, the output of the OR circuit ORT will indicate the approach of a hand to the lower area even if the first detection block 2521 fails to detect the approach of a hand to the lower area, as long as the second detection block 2522 detects a hand that is spread out and attempting to operate the touch sensor. Up to this point, we have determined whether Li(i=1, 2, 3, 4, 5, 6, 7) indicates the approach of a hand to the lower region by considering Li, Li+2, and L-2. However, depending on the arrangement of the proximity sensors IPS1-IPS17, we may also determine whether Li(i=1, 2, 3, 4, 5, 6, 7) indicates the approach of a hand to the lower region by setting A to an integer greater than or equal to 1 other than 2, and considering Li, Li+A, and LA in the same way as in the case of Li+2 and L-2.

[0041] Furthermore, the configurations of the lower region proximity detection unit 252 shown in Figures 5, 6, and 7, and the first detection block 2521 shown in Figure 8, may be modified by replacing SLj (j=3, 4, 5), which outputs the larger of Lj-2 and Lj+2, with the arithmetic unit CALj, which outputs ki[(Lj-2)+(Lj+2)]. However, ki is a tuning coefficient, and an appropriate value is determined and set in advance through experiments or other means so that the approach of a hand to the lower region is not detected for the installed object OBJ in Figure 3b1, but the approach of a hand to the lower region is detected for the operator's hand brought close to the lower touch sensor of the display 21.

[0042] Even in this manner, the same functions as the lower region approach detection unit 252 shown in Figures 5, 6, and 7, and the first detection block 2521 shown in Figure 8 can be achieved. Next, the configuration of the lower region proximity detection unit 252 may be equivalent to the logic circuit shown in Figure 9. As shown in the figure, in this configuration, the lower region approach detection unit 252 has seven comparators CP1-CP7, seven frequency-selective filters FSF1-FSF7, and a logical OR circuit. CPi(i=1, 2, 3, 4, 5, 6, 7) compares Li, which has passed through the frequency selection filter FSFi, with a preset threshold Thi, outputting 1 when Li is greater, and 0 otherwise. The OR gate outputs 1 when any of CP1-CP7 outputs 1, and 0 when all of CP1-CP7 outputs 0. The output of a logical OR circuit is 1, which indicates that the hand is approaching the lower region, and 0, which indicates that it is not approaching. Here, the OBJ (Object OBJ) suspended from the car's rearview mirror swings. The period of the OBJ's swing is a constant period corresponding to the length of the OBJ as a pendulum, and this length is within a certain range when it is located in front of the upper part of the display 21. Therefore, the period of the OBJ's swing and the period of the reflected light from the OBJ detected by IPS1-IPS7 are also within a certain range. Consequently, the reflected light from the OBJ detected by IPS1-IPS7 has a frequency within a certain range. Furthermore, this certain range of frequencies is different from the frequency band of the reflected light from the operator's hand.

[0043] Therefore, by pre-setting the frequency gain characteristics that cut out components within a certain frequency range as the frequency gain characteristics of the frequency selective filters FSF1-FSF7, it is possible to detect approach to the lower region of the operator's hand without detecting approach to the lower region of the installed object OBJ.

[0044] Furthermore, the frequency band of the reflected light from the installed object OBJ is higher than the frequency band of the reflected light obtained from the normal operation of the touch sensor operated by the operator's hand. Therefore, a Low Pass Filter (LPF) may be used as the frequency selective filters FSF1-FSF7. Now, returning to Figure 1, the touch detection unit 23, which detects touches from the touch sensors TS1-TS4, increases the sensitivity of touch detection when the lower area proximity detection unit 252 detects that the operator's hand is approaching the lower area, and decreases the sensitivity of touch detection when it detects that the operator's hand is not approaching the lower area.

[0045] This sensitivity control is performed, for example, as shown in Figure 10, by making the touch detection threshold, which consists of a detection threshold (a capacitance threshold for touch sensors TS1-TS4 that detect a touch when no touch is detected) and a dedetection threshold (a capacitance threshold for touch sensors TS1-TS4 that dedetects a touch when a touch is detected), smaller when the lower region proximity detection unit 252 detects that the operator's hand is approaching the lower region than when it detects that the operator's hand is not approaching the lower region.

[0046] The touch detection unit 23 notifies the data processing unit 1 of whether or not a touch occurred on the touch sensors TS1-TS4 and the location of the touch. Upon receiving notification of a touch on the touch sensors TS1-TS4, the data processing unit 1 performs predetermined processing according to the touched touch sensor, the touch location, and any changes in the touch location. For example, if the notified content represents a slide operation of a touch sensor for volume adjustment, the data processing unit 1 performs processing to adjust the output level of the output sound according to the sliding direction.

[0047] Embodiments of the present invention have been described above. By the way, in the above embodiment, seven proximity sensors IPS1-IPS7, each equipped with an infrared LED and a photodiode (PD), were used as the proximity sensor unit 24. However, the same or different numbers of infrared LEDs and photodiodes (PDs) may be used as the proximity sensor unit 24. For example, as shown in Figure 11a, six infrared LEDs are arranged side by side in the order LED1, LED2, LED3, LED4, LED5, and LED6 in the area below the placement area of ​​the touch sensors (TS1-TS4), with PD1 placed between LED1 and LED2, PD2 between LED3 and LED4, and PD3 between LED5 and LED6. Then, as shown in Figure 11b, the infrared LEDs are sequentially illuminated in the order of LED1, LED2, LED3, LED4, LED5, and LED6. The reflected light intensity detected by PD1 during the illumination of LED1 is set as LP1, the reflected light intensity detected by PD1 during the illumination of LED2 is set as LP2, the reflected light intensity detected by PD2 during the illumination of LED3 is set as LP3, the reflected light intensity detected by PD2 during the illumination of LED4 is set as LP4, the reflected light intensity detected by PD3 during the illumination of LED5 is set as LP5, and the reflected light intensity detected by PD3 during the illumination of LED6 is set as LP6. By using LPi (i=1, 2, 3, 4, 5, 6) in place of the reflected light intensity Li detected by IPsi in the above embodiment, the proximity sensor unit 24 functions in the same way as when there are six proximity sensors in the above embodiment. Furthermore, in the above embodiments, the proximity sensors (IPS1-IPS7), infrared LEDs (LED1-LED6), and photodiodes (PD1-PD3) were placed in the area below the placement area of ​​the touch sensors (TS1-TS4). However, the proximity sensors (IPS1-IPS7), infrared LEDs (LED1-LED6), and photodiodes (PD1-PD3) may also be placed in the area between the touch sensors (TS1-TS4) and the display 21 above the placement area, as shown for the proximity sensor (IPS1-IPS7) in Figure 12a.

[0048] Alternatively, the touch sensors (TS1-TS4) may be formed from a material that transmits infrared light, such as a transparent electrode, and the proximity sensors (IPS1-IPS7), infrared LEDs (LED1-LED6), and photodiodes (PD1-PD3) may be placed behind the touch sensors (TS1-TS4), as shown in Figure 12b for the proximity sensors (IPS1-IPS7).

[0049] Furthermore, in the above embodiments, the number of proximity sensors (IPS) and infrared LEDs (LEDs) may be any number of 4 or more, except when the lower region proximity detection unit 252 is configured as shown in Figure 9. Also, except in the case shown in Figure 9, if Li, Li+1, and Li-1 are considered instead of Li, Li+2, and Li-2 as described above to determine whether Li indicates the approach of a hand to the lower region, the number of proximity sensors (IPS) and infrared LEDs (LEDs) may be any number of 3 or more.

[0050] Furthermore, if the lower region proximity detection unit 252 is configured as shown in Figure 9, the number of proximity sensors (IPS) and infrared LEDs (LEDs) can be any number. [Explanation of Symbols]

[0051] 1...Data processing device, 2...Display unit, 3...Peripheral device, 21...Display, 22...Touch sensor unit, 23...Touch detection unit, 24...Proximity sensor unit, 25...Proximity detection unit, 251...Display surface proximity detection unit, 252...Lower area proximity detection unit, 2521...First detection block, 2522...Second detection block.

Claims

1. A touch detection system comprising a display and a touch sensor positioned below the lower edge of the display surface of the display, Three or more light sources are arranged side by side in the left-right direction of the display, below the lower edge of the display surface of the display, and emit invisible light upward toward the front of the display surface. Each of the aforementioned light sources is provided with a light detection means for detecting reflected invisible light emitted from the light source, A touch detection means for detecting a touch of the touch sensor with a set detection sensitivity, The system includes a detection sensitivity setting means for setting the detection sensitivity of the touch detection means, The detection sensitivity setting means determines whether detection is present when a predetermined condition is met for any i, where i is the order of arrangement of the light sources along the left-right direction, and sets the detection sensitivity of the touch detection means to the first sensitivity, and otherwise sets the detection sensitivity of the touch detection means to a second sensitivity which is lower than the first sensitivity. The aforementioned predetermined condition is necessary for the intensity of reflected light from the i-th light source detected by the light detection means to be greater than a predetermined threshold, and is a condition that is not met if the reference reflected light intensity is greater than a level determined from a predetermined standard. The aforementioned reference reflected light intensity is characterized in that, with A being an integer of 1 or more, if both the i+A-th light source and the iA-th light source are present, the larger of the intensity of reflected light from the i+A-th light source detected by the light detection means and the intensity of reflected light from the iA-th light source; and if only one of the i+A-th light source and the iA-th light source is present, the reflected light intensity from the present light source detected by the light detection means.

2. A touch detection system comprising a display and a touch sensor positioned below the lower edge of the display surface of the display, Three or more light sources are arranged side by side in the left-right direction of the display, below the lower edge of the display surface of the display, and emit invisible light upward toward the front of the display surface. Each of the aforementioned light sources is provided with a light detection means for detecting reflected invisible light emitted from the light source, A touch detection means for detecting a touch of the touch sensor with a set detection sensitivity, The system includes a detection sensitivity setting means for setting the detection sensitivity of the touch detection means, The detection sensitivity setting means determines whether detection is present when a predetermined condition is met for any i, where i is the order of arrangement of the light sources along the left-right direction, and sets the detection sensitivity of the touch detection means to the first sensitivity, and otherwise sets the detection sensitivity of the touch detection means to a second sensitivity which is lower than the first sensitivity. The aforementioned predetermined condition is necessary for the intensity of reflected light from the i-th light source detected by the light detection means to be greater than a predetermined threshold, and is a condition that is not met if the reference reflected light intensity is greater than a level determined from a predetermined standard. The aforementioned reference reflected light intensity is characterized in that, with A being an integer of 1 or more, if both the i+A-th light source and the iA-th light source are present, it is the sum of the intensity of reflected light from the i+A-th light source and the intensity of reflected light from the iA-th light source detected by the light detection means, and if only one of the i+A-th light source and the iA-th light source is present, it is the intensity of reflected light from the present light source detected by the light detection means.

3. A touch detection system according to claim 1 or 2, The touch detection system is characterized in that, for any i, the detection sensitivity setting means determines that detection is present when the value obtained by subtracting the reference reflected light intensity from the intensity of the reflected light of the i-th light source detected by the light detection means is greater than a predetermined threshold, and sets the detection sensitivity of the touch detection means to the first sensitivity, and sets the detection sensitivity of the touch detection means to the second sensitivity in other cases.

4. A touch detection system according to claim 1 or 2, The touch detection system is characterized in that, for any i, the detection sensitivity setting means determines that detection is present when the intensity of reflected light from the i-th light source detected by the light detection means is greater than a predetermined threshold and the reference reflected light intensity is not greater than a predetermined value, and sets the detection sensitivity of the touch detection means to the first sensitivity, and sets the detection sensitivity of the touch detection means to the second sensitivity in other cases.

5. A touch detection system according to claim 1 or 2, The touch detection system is characterized in that, for any i, the detection sensitivity setting means determines that detection is present when the intensity of reflected light from the i-th light source detected by the light detection means is greater than a threshold set so that the intensity increases as the reference reflected light intensity increases, and sets the detection sensitivity of the touch detection means to the first sensitivity, and sets the detection sensitivity of the touch detection means to the second sensitivity in other cases.

6. A touch detection system according to claim 1 or 2, A touch detection system characterized in that A=2.

7. A touch detection system comprising a display and a touch sensor positioned below the lower edge of the display surface of the display, Three or more light sources that emit invisible light toward the front of the display surface are arranged side by side in the left-right direction of the display on the lower side of the lower edge of the display surface of the display, Each of the aforementioned light sources is provided with a light detection means for detecting reflected invisible light emitted from the light source, A touch detection means for detecting a touch of the touch sensor with a set detection sensitivity, The system includes a detection sensitivity setting means for setting the detection sensitivity of the touch detection means, The aforementioned detection sensitivity setting means includes a first detection means, a second detection means, and a detection determination unit. The first detection means determines whether detection is present if a predetermined condition is met for any i, where i is the order of arrangement of the light sources along the left-right direction. The aforementioned predetermined condition is necessary for the intensity of reflected light from the i-th light source detected by the light detection means to be greater than a predetermined threshold, and is a condition that is not met if the reference reflected light intensity is greater than a level determined from a predetermined standard. The aforementioned reference reflected light intensity is, with A being an integer of 1 or more, the larger of the intensity of reflected light from the i+A-th light source and the intensity of reflected light from the iA-th light source detected by the light detection means when both the i+A-th light source and the iA-th light source are present, and the intensity of reflected light from the present light source detected by the light detection means when only one of the i+A-th light source and the iA-th light source is present. The second detection means determines whether detection is present if, for any i, the intensity of the reflected light from the i-th light source detected by the light detection means is greater than the predetermined threshold, or a predetermined second threshold. The touch detection system is characterized in that the detection determination unit sets the detection sensitivity of the touch detection means to a first sensitivity when at least one of the first detection means and the second detection means determines that detection is present, and sets the detection sensitivity of the touch detection means to a second sensitivity which is lower than the first sensitivity in other cases.

8. A touch detection system comprising a display and a touch sensor positioned below the lower edge of the display surface of the display, Three or more light sources that emit invisible light toward the front of the display surface are arranged side by side in the left-right direction of the display on the lower side of the lower edge of the display surface of the display, Each of the aforementioned light sources is provided with a light detection means for detecting reflected invisible light emitted from the light source, A touch detection means for detecting a touch of the touch sensor with a set detection sensitivity, The system includes a detection sensitivity setting means for setting the detection sensitivity of the touch detection means, The aforementioned detection sensitivity setting means includes a first detection means, a second detection means, and a detection determination unit. The first detection means determines whether detection is present if a predetermined condition is met for any i, where i is the order of arrangement of the light sources along the left-right direction. The aforementioned predetermined condition is necessary for the intensity of reflected light from the i-th light source detected by the light detection means to be greater than a predetermined threshold, and is a condition that is not met if the reference reflected light intensity is greater than a level determined from a predetermined standard. The reference reflected light intensity is the sum of the intensity of reflected light from the i+A-th light source and the intensity of reflected light from the iA-th light source detected by the light detection means, where A is an integer of 1 or more. If both the i+A-th light source and the iA-th light source are present, the reference reflected light intensity is the intensity of reflected light from the present light source detected by the light detection means if only one of the i+A-th light source or the iA-th light source is present. The second detection means determines whether detection is present if, for any i, the intensity of the reflected light from the i-th light source detected by the light detection means is greater than the predetermined threshold, or a predetermined second threshold. The touch detection system is characterized in that the detection determination unit sets the detection sensitivity of the touch detection means to a first sensitivity when at least one of the first detection means and the second detection means determines that detection is present, and sets the detection sensitivity of the touch detection means to a second sensitivity which is lower than the first sensitivity in other cases.

9. A touch detection system comprising a display and a touch sensor positioned below the lower edge of the display surface of the display, Multiple light sources that emit invisible light toward the front of the display surface are arranged side by side in the left-right direction on the lower side of the lower edge of the display surface of the display, Each of the aforementioned light sources is provided with a light detection means for detecting reflected invisible light emitted from the light source, A touch detection means for detecting a touch of the touch sensor with a set detection sensitivity, The system includes a detection sensitivity setting means for setting the detection sensitivity of the touch detection means, The touch detection system is characterized in that, for any i, the detection sensitivity setting means determines that detection is present and sets the detection sensitivity of the touch detection means to the first sensitivity, and otherwise sets the detection sensitivity of the touch detection means to a second sensitivity which is lower than the first sensitivity, when the magnitude of the signal obtained by attenuating the frequency component in the frequency band of vibration of an object that may be installed hanging in front of the upper part of the display surface of the display is greater than a threshold, and the detection sensitivity of the touch detection means is set to the first sensitivity, and otherwise sets the detection sensitivity of the touch detection means to a second sensitivity which is lower than the first sensitivity.

10. A touch detection system according to claim 1, 2, 7, 8, or 9, The aforementioned display is a touch detection system characterized by being positioned on the top surface of the dashboard of an automobile.

Images