JP2020013171A - Sensor system - Google Patents

Abstract

To provide a sensor system capable of preventing malfunction.SOLUTION: A sensor system 1 includes a projection optical system 10 that forms a real image of a projection objection 2 as an aerial image 3 in the air, a capacitive sensor 20 that is a capacitive sensor in which a capacitance value increases as a detection object 4 approaches in a detection space D1 and that outputs detection signal based on the capacitance value, and a control unit 30 that outputs a control signal for controlling a control target device 90 when receiving the detection signal. At least a part of the aerial image 3 exists in a space where the capacitance value is equal to or more than first threshold value th1 and equal to or less than a second threshold value th2 in the detection space D1. The capacitive sensor 20 outputs the detection signal when satisfying a predetermined condition in a case where the capacitance value exceeds the first threshold value th1 and does not exceed the second threshold value th2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sensor system.

  2. Description of the Related Art Conventionally, a technique for detecting a human operation on an aerial image is known. For example, Patent Literature 1 discloses an optical system that can detect that a human hand touches an aerial image using a TOF (Time Of Flight) type infrared sensor. Further, Patent Document 2 discloses an aerial video interaction device that detects a user's access to an aerial video by identifying the user's position by photographing the user using a camera.

International Publication No. 2012/133279 International Publication No. 2008/123500

  However, in the above-described conventional technology, since an optical sensor such as an infrared sensor or a camera is used, reflected light may be detected even when an operation on an aerial image is not performed, and there is a problem that a malfunction occurs. Specifically, when an object exists on a line connecting the light receiving element and the aerial image, the reflected light is detected in the same manner as when operating the aerial image. For example, when a hand or body accidentally passes by the optical sensor side of the image, reflected light is detected, and a malfunction occurs.

  Therefore, an object of the present invention is to provide a sensor system that can suppress malfunction.

  In order to achieve the above object, a sensor system according to one embodiment of the present invention includes a projection optical system that forms a real image of a projection target in the air as an aerial image, and the closer the detection target in the detection space, the more the electrostatic A capacitance-type sensor having a large capacitance value, the capacitance-type sensor outputting a detection signal based on the capacitance value, and for controlling a device to be controlled when the detection signal is received. A control unit that outputs a control signal of the aerial image, at least a part of the aerial image exists in a space where the capacitance value is equal to or more than a first threshold and equal to or less than a second threshold in the detection space, and The capacitive sensor outputs the detection signal when a predetermined condition is satisfied when the capacitance value does not exceed the second threshold after exceeding the first threshold.

  According to the sensor system of the present invention, malfunctions can be suppressed.

FIG. 2 is a cross-sectional view schematically illustrating a configuration of the sensor system according to the first embodiment. FIG. 2 is a block diagram illustrating a configuration of a sensor system according to Embodiment 1. FIG. 4 is a diagram schematically illustrating a relationship between a detection space of a capacitance type sensor and a capacitance value in the sensor system according to the first embodiment. FIG. 3 is a diagram showing an example of a user touching an aerial image in the sensor system according to the first embodiment. FIG. 5 is a diagram for explaining an operation of the sensor system according to the movement of the user shown in FIG. 4. FIG. 7 is a diagram illustrating another example of contact of a user with an aerial image in the sensor system according to Embodiment 1. FIG. 7 is a diagram for explaining an operation of the sensor system according to the movement of the user shown in FIG. 6. FIG. 7 is a cross-sectional view schematically illustrating a configuration of a sensor system according to a second embodiment. FIG. 14 is a diagram illustrating an example of a user touching an aerial image in the sensor system according to the second embodiment. FIG. 10 is a diagram for explaining an operation of the sensor system according to the movement of the user shown in FIG. 9.

  Hereinafter, a sensor system according to an embodiment of the present invention will be described in detail with reference to the drawings. Each of the embodiments described below shows a specific example of the present invention. Therefore, numerical values, shapes, materials, constituent elements, arrangement and connection forms of constituent elements, steps, order of steps, and the like shown in the following embodiments are merely examples, and do not limit the present invention. Therefore, among the components in the following embodiments, components that are not described in the independent claims that represent the highest concept of the present invention are described as arbitrary components.

  In addition, each drawing is a schematic diagram, and is not necessarily strictly illustrated. Therefore, for example, the scales and the like do not always match in each drawing. Further, in each of the drawings, substantially the same configuration is denoted by the same reference numeral, and redundant description will be omitted or simplified. Further, in the following embodiments, expressions using “substantially” such as approximately coincident or approximately vertical are used. For example, an approximate match means not only a perfect match but also a substantial match, that is, including a difference of, for example, about several percent. The same applies to expressions using other “abbreviations”.

(Embodiment 1)
[Constitution]
First, the configuration of the sensor system 1 according to the present embodiment will be described with reference to FIGS. FIG. 1 is a cross-sectional view schematically illustrating a configuration of a sensor system 1 according to the present embodiment. FIG. 2 is a block diagram showing a configuration of the sensor system 1 according to the present embodiment.

  As shown in FIGS. 1 and 2, the sensor system 1 displays an aerial image 3 in the air by forming a real image of the projection target 2 in the air, and operates the user on the displayed aerial image 3. Is a system that detects At least a part of the aerial image 3 exists in the detection space D1. When the aerial image 3 is operated by the detection target 4 such as a user's hand or finger, the sensor system 1 controls the control target device 90 according to the operation.

  In FIG. 1, the path of light emitted from the projection target 2 is indicated by a broken line. The arrow shown by the broken line indicates the traveling direction of light. This is the same in FIG. 8 described later.

  In the present embodiment, the projection target 2 is an image (video) displayed on a display surface (or screen) by a display device such as a display or a projector. The projection target 2 may be, for example, either a still image or a moving image. The projection target 2 is, for example, a content image stored in a storage device included in the display device, a video or recorded image of a broadcasted television program, a BD (Blu-ray (registered trademark) Disc) or a DVD (Digital Versatile Disc). , Or a streaming video via the Internet.

  Since the aerial image 3 is a real image of the projection target 2, the display content (content) of the aerial image 3 matches the projection target 2.

  The detection target 4 is a part of a living body such as a user's hand or finger, but is not limited thereto. For example, the detection target 4 may be an inorganic substance.

  The control target device 90 is a device controlled by the sensor system 1. Specifically, the control target device 90 is controlled in accordance with a user operation on the aerial image 3.

  In the present embodiment, the control target device 90 is a display that displays the projection target 2. The control target device 90 changes the video (or image) displayed on the projection target 2, that is, the display surface, based on the control by the sensor system 1. Thereby, the display content of the aerial image 3 is changed.

  As described above, according to the present embodiment, when the user operates the aerial image 3, the display content of the aerial image 3 can be changed.

  As shown in FIG. 2, the sensor system 1 includes a projection optical system 10, a capacitance sensor 20, and a control unit 30. Hereinafter, each component of the sensor system 1 will be described with reference to FIGS. 1 and 2 as appropriate.

[Projection optical system]
The projection optical system 10 forms a real image of the projection target 2 as an aerial image 3 in the air. As shown in FIG. 1, the projection optical system 10 includes a half mirror 11 and a retroreflective member 12.

  The projection optical system 10 displays the aerial image 3 at a plane symmetric position of the projection target 2 with respect to the half mirror 11. Specifically, a virtual straight line connecting a predetermined part of the projection target 2 and a part of the aerial image 3 corresponding to the part is orthogonal to the half mirror 11. The projection target 2 and the aerial image 3 are located at the same distance from the half mirror 11, respectively. The aerial image 3 has the same size as the projection target 2.

  The half mirror 11 is an example of a beam splitter that emits reflected light and transmitted light by reflecting and transmitting light emitted from the projection target 2. Specifically, the half mirror 11 specularly reflects a part of the incident light, and transmits the rest as it is (without substantially changing the traveling direction). The half mirror 11 reflects and transmits incident light at approximately 1: 1 for example. That is, the half mirror 11 emits 50% of reflected light and 50% of transmitted light of the light beam of the incident light.

  The half mirror 11 is, for example, a translucent plate material having a reflective thin film such as a metal thin film or a dielectric multilayer film formed on the surface. The translucent plate material is formed using, for example, a glass material such as transparent soda glass or a transparent resin material such as acrylic (PMMA) or polycarbonate (PC). The metal thin film is a thin film formed using a metal material such as aluminum so as to have light transmittance and light reflectivity.

  The half mirror 11 reflects the light emitted from the projection target 2 toward the retroreflective member 12. The half mirror 11 transmits light retroreflected from the retroreflective member 12. The transmitted retroreflected light forms an image in a space on the opposite side of the projection target 2 with respect to the half mirror 11. Thereby, the aerial image 3 which is the real image of the projection target 2 is displayed in the air.

  The retroreflective member 12 retroreflects the light reflected by the half mirror 11. In the present embodiment, the retroreflective member 12 is located on the same side as the projection target 2 with respect to the half mirror 11.

  The retroreflective member 12 is, for example, a sheet-like member in which a plurality of spherical glass beads are spread in a plane of a plate-like base material. Alternatively, the retroreflective member 12 may be a plate member provided with a microprism.

  In the present embodiment, the retroreflective member 12 is disposed so as to be inclined at a predetermined angle with respect to the half mirror 11, but is not limited thereto. The retroreflective member 12 only needs to be located on the optical path of the light reflected by the half mirror 11, and may be arranged in a posture substantially perpendicular to the half mirror 11.

[Capacitance sensor]
The capacitance-type sensor 20 is a capacitance-type sensor whose capacitance value increases as the detection target object 4 approaches the detection space D1, and outputs a detection signal based on the capacitance value. The detection signal is a signal indicating that the detection target object 4 has been detected.

  As shown in FIG. 1, the capacitance type sensor 20 includes a substrate 21 and a detection electrode 22. The capacitance sensor 20 detects the detection target 4 based on a capacitance value between the detection electrode 22 and the detection target 4.

  The substrate 21 is, for example, a resin substrate made of a resin material or a metal base substrate coated with a metal by insulation. The substrate 21 has, for example, a circular shape in plan view, but is not limited thereto and may have a rectangular shape.

  The detection electrode 22 is formed in a predetermined pattern on one surface of the substrate 21 using, for example, a metal material such as copper or silver. Specifically, the detection electrode 22 is a solid electrode having a circular shape in plan view. The detection electrode 22 outputs a signal indicating a time change of a capacitance value generated between the detection electrode 22 and the detection target object 4. In the present embodiment, the substrate 21 and the detection electrode 22 of the capacitance type sensor 20 are arranged so as to be substantially parallel to the main surface of the half mirror 11 of the projection optical system 10.

  The detection space D1 of the capacitance type sensor 20 is formed so as to extend forward (the side opposite to the substrate 21) from the detection electrode 22. For example, the shape of the detection space D1 is spherical (part of a sphere) or dome. The planar shape of the detection space D1 is, for example, a circle. The plan view means a case where the detection electrode 22 is viewed from the front. The center axis P of the detection space D1 is a straight line that passes through the center of a circle that is the shape of the detection space D1 in a plan view, and is a virtual straight line that is substantially perpendicular to the detection electrode 22 at a substantially central portion of the detection electrode 22.

  In the present embodiment, as shown in FIG. 1, at least a part of the aerial image 3 exists in the detection space D1 and exists on the central axis P. At least a part of the projection target 2 exists on the central axis P of the detection space D1. For example, a virtual straight line connecting the central part of the projection target 2 and the central part of the aerial image 3 substantially coincides with the central axis P.

  Here, the relationship between the detection space D1 and the capacitance value will be described with reference to FIG. FIG. 3 is a diagram schematically illustrating the relationship between the detection space D1 of the capacitance type sensor 20 and the capacitance value in the sensor system 1 according to the present embodiment.

  The capacitance value between the capacitance type sensor 20 and the detection target 4 increases as the detection target 4 approaches. Specifically, there is a negative correlation between the distance from the detection electrode 22 and the capacitance value between the detection object 4 and the distance. By utilizing the correlation, the detection space D1 of the capacitance type sensor 20 can be defined based on the capacitance value between the detection space D1 and the detection target object 4.

  For example, when the detection target 4 (the tip) exists on the solid line indicated by “th1” in FIG. 3, the capacitance value becomes equal to the first threshold th1. In the present embodiment, the detection space D1 is a space surrounded by the solid line. Specifically, the detection space D1 is a space where the capacitance value between the detection space D1 and the detection target object 4 is equal to or larger than the first threshold th1. In other words, when the detection target object 4 exists in the detection space D1, the capacitance value of the capacitance sensor 20 becomes a value equal to or more than the first threshold th1.

  In addition, when (the tip of) the detection target 4 exists on the broken line indicated by “th2” in FIG. 3, the capacitance value becomes equal to the second threshold th2. The second threshold value th2 is a value larger than the first threshold value th1. A space surrounded by a broken line indicated by “th2” in FIG. 3 indicates a space D2 in which the capacitance value is equal to or larger than the second threshold th2. The space D2 is formed in the detection space D1 and at a portion closer to the detection electrode 22.

  The capacitance value exceeds the first threshold th1 when the detection target 4 enters the detection space D1, and falls below the first threshold th1 when the detection target 4 exits the detection space D1. Similarly, the capacitance value exceeds the second threshold th2 when the detection target 4 enters the space D2, and falls below the second threshold th2 when the detection target 4 exits the space D2.

  The size of the detection space D1 is, for example, within a range of several cm to several tens of cm from the detection electrode 22 on the central axis P, but is not limited thereto. It can be set appropriately according to the usage environment of the sensor system 1 and the like.

  The capacitance sensor 20 outputs a detection signal when a predetermined condition is satisfied in a case where the capacitance value does not exceed the second threshold th2 after exceeding the first threshold th1. The predetermined condition is a condition that the capacitance value must satisfy in order for the capacitance sensor 20 to output a detection signal. The specific conditions and the specific operation of the capacitance type sensor 20 will be described later.

[Control unit]
When receiving the detection signal, the control unit 30 outputs a control signal for controlling the control target device 90. The control unit 30 is connected to the control target device 90 by wire or wirelessly. By transmitting a control signal to the control target device 90 by wire communication or wireless communication, the operation of the control target device 90 is controlled.

  In the present embodiment, when the user operates the aerial image 3 with a finger (detection target 4), the capacitance sensor 20 detects the detection target 4 and outputs a detection signal. The control target device 90 is controlled by the control. For example, when the control target device 90 is a display that displays the projection target object 2, the control unit 30 generates a control signal for changing the display content of the projection target object 2, and transmits the control signal to the control target device 90. . Thus, the display content of the aerial image 3 (projection target 2) can be changed by the user operating the aerial image 3.

  The control unit 30 is realized by, for example, a microcomputer (microcontroller). The control unit 30 is realized by, for example, a nonvolatile memory storing a program, a volatile memory serving as a temporary storage area for executing the program, an input / output port, a processor executing the program, and the like.

[motion]
Subsequently, an operation of the sensor system 1 according to the present embodiment will be described.

  The sensor system 1 according to the present embodiment detects a user operation on the aerial image 3. At this time, two modes can be considered as a user's operation mode for the aerial image 3. Specifically, two modes are a touch operation and a stroke operation. Hereinafter, the operation of the sensor system 1 according to each of the two aspects will be described.

[Touch operation]
First, the touch operation will be described with reference to FIGS.

  FIG. 4 is a diagram illustrating an example of a user touching the aerial image 3 (touch operation) in the sensor system 1 according to the present embodiment. FIG. 5 is a diagram for explaining the operation of the sensor system 1 according to the movement of the user shown in FIG.

  As shown in FIG. 4, at least a part of the aerial image 3 exists in the detection space D1 in a space where the capacitance value is equal to or more than the first threshold th1 and equal to or less than the second threshold th2. That is, at least a part of the aerial image 3 exists in a space excluding the space D2 in the detection space D1. As one of operations for the user to operate the aerial image 3, the hand (the detection target 4) is moved to the display position of the aerial image 3 so as to be superimposed on the aerial image 3, and after a short time, the hand is moved. There is a pulling action (solid and dashed arrows in FIG. 4). In this specification, the operation is referred to as “touch operation”.

  When the touch operation is performed, the hand that is the detection target 4 enters the detection space D1 of the capacitive sensor 20 and then leaves the detection space D1 without entering the space D2. At this time, the capacitance value of the capacitance sensor 20 draws a curve C1 indicated by a solid line in FIG. Specifically, the capacitance value gradually increases, exceeds the first threshold th1, and is maintained for a certain period between the first threshold th1 and the second threshold th2. Thereafter, the capacitance value gradually decreases and falls below the first threshold th1 in accordance with the operation of pulling the hand (the detection target 4).

  In the present embodiment, when the state in which the capacitance value is equal to or larger than the first threshold th1 and equal to or smaller than the second threshold th2 continues for a predetermined first period Tth1 or more, a predetermined condition is satisfied. A detection signal is output as being satisfied. The capacitance-type sensor 20 does not output a detection signal when the duration in which the capacitance value is equal to or more than the first threshold th1 and equal to or less than the second threshold th2 is shorter than the first period Tth1. The predetermined first period Tth1 is, for example, 1 second or less, and is 0.4 seconds as an example.

  Normally, it takes 0.4 seconds or more for the user to move the hand (detection target 4) to the aerial image 3 and retract it (that is, touch operation). Therefore, as shown by a solid curve C1 in FIG. 5, a period T1 required for the capacitance value to exceed the first threshold th1 after the capacitance exceeds the first threshold th1 is longer than the first period Tth1. Therefore, when the first period Tth1 has elapsed since the capacitance value exceeded the first threshold th1, the capacitance sensor 20 outputs a detection signal. Thereby, the control unit 30 outputs a control signal to the control target device 90, and the control target device 90 is controlled.

  Here, the behavior of the capacitance value when the user performs an operation other than the touch operation on the aerial image 3 will be described.

  For example, it is assumed that the user has passed near the surface of the capacitance type sensor 20. Specifically, when the capacitance-type sensor 20 is embedded in a wall of a building or the like, the capacitance value of the capacitance-type sensor 20 changes when a person walks near the wall. I do.

  When such an operation is performed, the user who is the detection target object 4 enters the detection space D1 of the capacitive sensor 20, passes through the space D2, and exits the detection space D1. At this time, the capacitance value of the capacitance type sensor 20 draws a curve C2 indicated by a broken line in FIG. Specifically, as the user approaches the capacitance-type sensor 20, the capacitance value gradually increases, exceeds the first threshold th1, and then exceeds the second threshold th2. Thereafter, as the user moves away from the capacitance-type sensor 20, the capacitance value gradually decreases and sequentially falls below the second threshold th2 and the first threshold th1.

  In the case of an operation that is not a touch operation, since the operation is not stopped consciously, the period from entering the detection space D1 to entering the space D2 is sufficiently short. Therefore, as shown in FIG. 5, the period T2 from when the first threshold th1 is exceeded to when the second threshold th2 is exceeded is shorter than the first period Tth1. For this reason, since the capacitance type sensor 20 does not output the detection signal, the control unit 30 does not output the control signal, and the control target device 90 is not controlled.

  As described above, according to the sensor system 1 according to the present embodiment, the control target device 90 can be controlled by the touch operation. Further, according to the sensor system 1, in the case of an operation other than a touch operation, the control target device 90 is unintentionally controlled, that is, a malfunction can be suppressed.

[Stroke operation]
Next, the stroke operation will be described with reference to FIGS.

  FIG. 6 is a diagram illustrating another example of contact (stroke operation) of the user with the aerial image 3 in the sensor system 1 according to the present embodiment. FIG. 7 is a diagram for explaining the operation of the sensor system 1 according to the movement of the user shown in FIG.

  As shown in FIG. 6, as one of the operations for the user to operate the aerial image 3, the user moves the hand (the detection target 4) so as to pass through the display position of the aerial image 3 so as to pay the aerial image 3. There is an operation (solid arrow in FIG. 6). In this specification, the operation is referred to as “stroke operation”.

  When the stroke operation is performed, the hand that is the detection target 4 enters the detection space D1 of the capacitive sensor 20 and then leaves the detection space D1 without entering the space D2. At this time, the capacitance value of the capacitance type sensor 20 draws a curve C11 indicated by a solid line in FIG. Specifically, the capacitance value gradually increases and falls short of the first threshold th1 immediately after exceeding the first threshold th1.

  In the present embodiment, after the capacitance value exceeds the first threshold th1, the capacitance sensor 20 does not exceed the second threshold th2 within a period shorter than the predetermined second period Tth2. When the value falls below the threshold th1, a predetermined condition is satisfied and a detection signal is output. The capacitance-type sensor 20 is configured to exceed the first threshold th1 and then exceed the second threshold th2, or to exceed the first threshold th1 and fall below the first threshold th1 without exceeding the second threshold th2. Is longer than the second period Tth2, no detection signal is output. The predetermined second period Tth2 is a period shorter than the first period Tth1 used for determining a touch operation. The second period Tth2 is, for example, 0.2 seconds to 0.3 seconds.

  Normally, when the user operates to pay the aerial image 3 with his / her hand (the detection target object 4), a period during which the user touches the aerial image 3 (specifically, a period from when the first threshold th1 is exceeded to when it falls below). Is a sufficiently short period, such as 0.2 seconds or less. Therefore, as shown by the solid line curve C11 in FIG. 7, the period T11 from when the capacitance value exceeds the first threshold value th1 to when the capacitance value falls below the first threshold value th1 without exceeding the second threshold value th2 is equal to the second threshold value. It becomes shorter than the period Tth2. Therefore, when the capacitance value falls below the first threshold th1, the capacitance type sensor 20 outputs a detection signal. Thereby, the control unit 30 outputs a control signal to the control target device 90, and the control target device 90 is controlled.

  Here, the behavior of the capacitance value when the user performs an operation other than the stroke operation of the aerial image 3 will be described.

  For example, it is assumed that the user continues to exist near the surface of the capacitance type sensor 20. Specifically, when the capacitance type sensor 20 is embedded in a wall of a building or the like, when the user leans for a long time without noticing the presence of the capacitance type The capacitance value of the expression sensor 20 changes.

  When such an operation is performed, the user who is the detection target 4 enters the detection space D1 of the capacitive sensor 20 and continues to exist in the space D2 for a predetermined period. At this time, the capacitance value of the capacitance sensor 20 draws a curve C12 indicated by a broken line in FIG. Specifically, as the user approaches the capacitance-type sensor 20, the capacitance value gradually increases and sequentially exceeds the first threshold th1 and the second threshold th2. Since the user does not move as it is, the capacitance value is maintained in a state exceeding the second threshold value th2.

  In the case of an operation other than a stroke operation, an unintended change in the capacitance value and maintenance of the value are likely to occur. Therefore, after the capacitance value exceeds the first threshold value th1, the capacitance value is changed within a period shorter than the second period Tth2. It hardly falls below one threshold th1. For this reason, since the capacitance type sensor 20 does not output the detection signal, the control unit 30 does not output the control signal, and the control target device 90 is not controlled.

  As described above, according to the sensor system 1 according to the present embodiment, the control target device 90 can be controlled by the stroke operation. Further, according to the sensor system 1, in the case of an operation other than a stroke operation, the control target device 90 is unintentionally controlled, that is, a malfunction can be suppressed.

  In the present embodiment, the condition for outputting the detection signal in each of the touch operation and the stroke operation has been described. However, the capacitance type sensor 20 may use only one of the conditions. . Alternatively, the capacitance type sensor 20 may use both conditions. Specifically, the capacitance-type sensor 20 includes (i) when the state in which the capacitance value is equal to or more than the first threshold th1 and equal to or less than the second threshold th2 continues for the first period Tth1 or more, and (ii) When the capacitance value falls below the first threshold value without exceeding the second threshold value th2 within a period shorter than the second period Tth2 after the capacitance value exceeds the first threshold value th1, a detection is performed when at least one of the capacitance values falls below the first threshold value. A signal may be output. Thus, the control target device 90 can be controlled regardless of whether the touch operation or the stroke operation is performed. The user's contact with the aerial image 3 is not limited, so that user convenience can be improved.

[Effects, etc.]
As described above, the sensor system 1 according to the present embodiment is configured such that the projection optical system 10 that forms a real image of the projection target 2 in the air as the aerial image 3 and the detection target 4 closer to the detection space D1. A capacitance sensor having a large capacitance value, a capacitance sensor 20 that outputs a detection signal based on the capacitance value, and a control target device 90 when the detection signal is received. A control unit 30 that outputs a control signal for controlling, wherein at least a part of the aerial image 3 exists in a space where the capacitance value is equal to or more than the first threshold th1 and equal to or less than the second threshold th2 in the detection space D1. Then, the capacitance-type sensor 20 outputs a detection signal when a predetermined condition is satisfied when the capacitance value does not exceed the second threshold value th2 after exceeding the first threshold value th1.

  Thereby, in the sensor system 101, since the space where at least a part of the aerial image 3 exists and the range in which the detection signal is output correspond, for example, when the user operates (touches) the aerial image 3 , And outputs a detection signal to control the controlled device 90.

  Further, the capacitance type sensor 20 outputs a detection signal when a predetermined condition is satisfied from when the capacitance value exceeds the first threshold value th1 to when the capacitance value exceeds the second threshold value th2. Does not output the detection signal when the sensor is too close to the capacitance sensor 20 (that is, when the capacitance value exceeds the second threshold th2). Therefore, it is possible to suppress output of a detection signal when the operation of the aerial image 3 is not intended, such as when the detection target 4 accidentally crosses the vicinity of the surface of the capacitance type sensor 20. Thereby, malfunction (operation not intended by the user) of the control target device 90 can be suppressed.

  Further, for example, the capacitance-type sensor 20 satisfies a predetermined condition when the state in which the capacitance value is equal to or more than the first threshold th1 and equal to or less than the second threshold th2 continues for a predetermined first period Tth1 or more. And outputs a detection signal.

  Thus, when an operation (touch operation) such as placing a hand (detection target object 4) on the aerial image 3 is performed, a detection signal is output and the control target device 90 can be controlled. The control target device 90 can be appropriately controlled while suppressing a malfunction due to an operation other than the touch operation.

  Further, for example, after the capacitance value exceeds the first threshold value th1, the capacitance sensor 20 does not exceed the second threshold value th2 within a period shorter than the predetermined second period Tth2. , The detection signal is output assuming that a predetermined condition is satisfied.

  Accordingly, when an operation (stroke operation) of paying the aerial image 3 by hand (detection target object 4) is performed, a detection signal is output and the control target device 90 can be controlled. The control target device 90 can be appropriately controlled while suppressing a malfunction due to an operation other than the stroke operation.

  Also, for example, at least a part of the aerial image 3 exists on the central axis P of the detection space D1.

  Thereby, since at least a part of the aerial image 3 exists on the central axis of the detection space D1, the whole or most of the aerial image 3 exists in the detection space D1. Therefore, even when the user touches only a part of the aerial image 3, the capacitance value of the capacitance type sensor 20 changes, so that the detection signal is easily output. Thus, the sensing accuracy of the sensor system 1 can be improved.

(Embodiment 2)
Next, a second embodiment will be described.

[Constitution]
FIG. 8 is a cross-sectional view schematically illustrating a configuration of the sensor system 101 according to the present embodiment.

  The sensor system 101 according to the present embodiment is different from the first embodiment in that a capacitance sensor 120 is provided instead of the capacitance sensor 20 according to the first embodiment. The capacitance-type sensor 120 has the same configuration as the capacitance-type sensor 20 according to the first embodiment, and is different in the arrangement position.

  Specifically, the capacitance type sensor 120 is arranged so that the aerial image 3 does not exist on the central axis P of the detection space D1. That is, a virtual straight line connecting an arbitrary part of the projection target 2 and a part of the aerial image 3 corresponding to the part does not coincide with the central axis P.

  In the present embodiment, as shown in FIG. 8, the aerial image 3 exists below the central axis P in the detection space D1. Here, the downward direction is a direction approaching the retroreflective member 12 along the main surface of the half mirror 11. The upward direction is the opposite direction, specifically, the direction away from the retroreflective member 12 along the main surface of the half mirror 11. That is, FIG. 8 illustrates a case where the half mirror 11 is set upright so that the capacitance type sensor 120 is located above. For this reason, the user can look down at the aerial image 3 from obliquely above. The mode of installation of the half mirror 11 is not limited to this, and the half mirror 11 may be installed horizontally.

  In the present embodiment, the capacitive sensor 120 is located farther from the retroreflective member 12 than the capacitive sensor 20 according to the first embodiment (on the user's viewpoint side, that is, on the upper side). ). Thereby, the area of the effective area of the half mirror 11 can be increased. The effective area of the half mirror 11 is a range schematically shown by a double-headed arrow in FIG. 8, and is a portion where light emitted from the projection target 2 can be imaged as the aerial image 3.

  In the first embodiment, since the projection target 2 exists on the central axis P, a part of the light emitted from the projection target 2 is blocked by the capacitance sensor 20 (see FIG. 1). On the other hand, in the present embodiment, since the projection target 2 is located closer to the retroreflective member 12 than the center axis P, the amount of light that is radiated from the projection target 2 is reduced, and the projection target 2 is effective. The area can be enlarged. Thereby, the viewing angle which is a range in which the aerial image 3 can be viewed can be increased.

  Note that, as the capacitance type sensor 120 moves away from the retroreflective member 12, the viewing angle becomes wider, but the direct light from the projection target 2 easily enters the user's eyes. When direct light is incident on the eye, the visibility of the aerial image 3 is reduced.

  For this reason, as shown in FIG. 8, the lower end of the substrate 121 of the capacitive sensor 120 is located closer to the retroreflective member 12 than the line Q connecting the upper end of the projection target 2 and the upper end of the aerial image 3. are doing. Thereby, the direct light from the projection target 2 can be blocked by the substrate 121, and the visibility of the aerial image 3 can be improved.

[motion]
Subsequently, an operation of the sensor system 101 according to the present embodiment will be described.

  In the present embodiment, as shown in FIG. 8, the aerial image 3 is located below the central axis P, and the viewpoint of the user is located diagonally above the aerial image 3. Therefore, when the user attempts to operate the aerial image 3, the stroke operation is easier to perform than the touch operation. Therefore, the case where the stroke operation is performed will be described below.

  FIG. 9 is a diagram illustrating an example of contact (stroke operation) of the user with the aerial image 3 in the sensor system 101 according to the present embodiment. FIG. 10 is a diagram for explaining the operation of the sensor system 101 according to the movement of the user shown in FIG.

  As shown in FIG. 9, at least a part of the aerial image 3 exists at a position where the capacitance value matches the third threshold th3 in the detection space D1. The third threshold th3 is a value equal to or larger than the first threshold th1 and smaller than the second threshold th2. The third threshold th3 is, for example, a value larger than the first threshold th1 and a value closer to the first threshold th1 than the second threshold th2. For example, the aerial image 3 may exist near the boundary between the detection space D1 and the outside of the detection space D1.

  Note that the third threshold th3 may be equal to the first threshold th1. Alternatively, the third threshold th3 may be a value closer to the second threshold th2 than the first threshold th1 or an average value of the first threshold th1 and the second threshold th2.

  When the stroke operation is performed, the hand that is the detection target 4 enters the detection space D1 of the capacitance type sensor 120, and then leaves the detection space D1 without entering the space D2. At this time, the capacitance value of the capacitance type sensor 120 draws a curve C21 indicated by a solid line in FIG. Specifically, the capacitance value gradually increases, sequentially exceeds the first threshold th1 and the third threshold th3, and then sequentially falls below the third threshold th3 and the first threshold th1.

  In the present embodiment, when the capacitance value falls below the third threshold th3 after exceeding the third threshold th3, the capacitance sensor 120 outputs a detection signal assuming that a predetermined condition is satisfied. Since at least a part of the aerial image 3 exists at a position where the capacitance value matches the third threshold value th3 as shown in FIG. 9, a detection signal is output when the user touches the aerial image 3. Is done.

  At this time, when the capacitance value exceeds the third threshold th3, the capacitance sensor 120 does not output a detection signal. Accordingly, as shown in FIG. 9, when the hand (the detection target object 4) is swung down toward the aerial image 3, no detection signal is output immediately before the hand reaches the aerial image 3. Therefore, the detection signal is output before the user touches the aerial image 3, and the control of the control target device 90 can be suppressed.

[Effects, etc.]
As described above, in the sensor system 101 according to the present embodiment, for example, the aerial image 3 does not exist on the center axis P of the detection space D1.

  This makes it difficult for the capacitive sensor 20 to block the light emitted from the projection target 2, so that the viewing angle of the aerial image 3 can be increased.

  Further, for example, at least a part of the aerial image 3 exists at a position where the capacitance value matches a third threshold th3 that is equal to or larger than the first threshold th1 and smaller than the second threshold th2 in the detection space D1. When the capacitance value falls below the third threshold value th3 after exceeding the third threshold value th3, the expression sensor 20 outputs a detection signal assuming that a predetermined condition is satisfied.

  Thus, the capacitance sensor 120 determines whether to output a detection signal by comparing the capacitance value with the third threshold th3. That is, since it is not necessary to measure the period until the value falls below the threshold as in the first embodiment, the output of the detection signal can be determined with a simple circuit configuration (or program).

  Further, since the display position of the aerial image 3 corresponds to the third threshold th3, a detection signal is output at the timing when the user operates the aerial image 3, and the control target device 90 is controlled. As described above, since the operation of the aerial image 3 and the control of the control target device 90 are performed substantially simultaneously, the operation of the aerial image 3 is naturally felt by the user, and the discomfort can be reduced. For example, similarly to operating the physical button, the user can operate the aerial image 3 to control the control target device 90.

(Other)
As described above, the sensor system according to the present invention has been described based on the above embodiments, but the present invention is not limited to the above embodiments.

  For example, in the above-described embodiment, an example is described in which the retroreflective member 12 is disposed on the same side as the projection target 2 with respect to the half mirror 11, but the present invention is not limited thereto. The retroreflective member 12 may be arranged on the side opposite to the projection target object 2 with respect to the half mirror 11, that is, on the aerial image 3 side.

  In this case, the retroreflective member 12 retroreflects the light transmitted from the half mirror 11 among the light emitted from the projection target 2. Light retroreflected by the retroreflective member 12 is reflected by the half mirror 11. The reflected retroreflected light is imaged in a space on the same side as the retroreflective member 12 with respect to the half mirror 11 (the side opposite to the projection target 2). Thereby, the aerial image 3 which is the real image of the projection target 2 is displayed in the air.

  Further, for example, the projection optical system 10 may include a beam splitter having different transmittance and reflectance instead of the half mirror 11 having the same transmittance and reflectance of 50%.

  Further, for example, in the above-described embodiment, an example has been described in which the projection optical system 10 includes the half mirror 11 and the retroreflective member 12, but the invention is not limited thereto. The projection optical system 10 may form an image of the projection target 2 in the air, and may include, for example, a dihedral corner reflector array instead of the half mirror 11. In this case, the projection optical system 10 may not include the retroreflective member 12.

  Further, for example, in the above-described embodiment, an example in which the control target device 90 is a display or the like that displays the projection target object 2 has been described. The control target device 90 may be another device such as, for example, lighting equipment, sound equipment, and air conditioning equipment. Specifically, the control unit 30 may control on / off of the power of the lighting equipment, the audio equipment, or the air conditioning equipment. That is, the sensor system 1 can function as a power switch of various facilities.

  In addition, a form obtained by performing various modifications that can be conceived by those skilled in the art to each embodiment, and a combination of components and functions in each embodiment without departing from the spirit of the present invention are realized. Embodiments are also included in the present invention.

DESCRIPTION OF SYMBOLS 1, 101 Sensor system 2 Projection object 3 Aerial image 4 Detection object 10 Projection optical system 20, 120 Capacitive sensor 30 Control part 90 Controlled device D1 Detection space P Central axis

Claims (6)

A projection optical system that forms a real image of a projection target in the air as an aerial image,
A capacitance sensor whose capacitance value increases as the detection target approaches in the detection space, wherein the capacitance sensor outputs a detection signal based on the capacitance value.
When receiving the detection signal, comprising a control unit that outputs a control signal for controlling the device to be controlled,
At least a part of the aerial image exists in a space where the capacitance value is equal to or greater than a first threshold and equal to or less than a second threshold in the detection space,
The sensor system, wherein the capacitance sensor outputs the detection signal when a predetermined condition is satisfied in a case where the capacitance value does not exceed the second threshold after exceeding the first threshold. The capacitance-type sensor detects that the predetermined condition is satisfied when the state where the capacitance value is equal to or more than the first threshold and equal to or less than the second threshold continues for a predetermined first period or more. The sensor system according to claim 1, which outputs a signal. When the capacitance value sensor falls below the first threshold without exceeding the second threshold within a period shorter than a predetermined second period after the capacitance value exceeds the first threshold. The sensor system according to claim 1, wherein the detection signal is output assuming that the predetermined condition is satisfied. The sensor system according to any one of claims 1 to 3, wherein at least a part of the aerial image exists on a center axis of the detection space. The sensor system according to claim 1, wherein the aerial image does not exist on a central axis of the detection space. At least a portion of the aerial image is present at a position where the capacitance value in the detection space matches a third threshold that is greater than or equal to the first threshold and smaller than the second threshold.
The capacitance type sensor outputs the detection signal as satisfying the predetermined condition when the capacitance value falls below the third threshold value after the capacitance value exceeds the third threshold value. The sensor system as described.

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