JP7654946B2 - Non-contact switch - Google Patents

Description

The present invention relates to a non-contact switch that allows for non-contact operation input.

From the standpoint of hygiene and preventing the spread of infectious diseases, research is being conducted into non-contact switches that allow users to input operations without touching any parts (see, for example, Patent Document 1).

For example, the input device disclosed in Patent Document 1 includes a light source, a light guide plate, a sensor, and a second image. The light guide plate guides light from the light source to form a first image in space. The sensor detects an object in the space including the imaging position of the first image, or in a space a predetermined distance away from the imaging position of the first image. The second image is displayed on a surface different from the surface on which the first image is displayed. Then, the controller changes the first image to be displayed in response to the user's input operation on the first image. Furthermore, a light guide plate or a display device for displaying the second image is provided, and the second image displayed by the controller is changed in response to the input operation.

JP 2020-64632 A

The input device disclosed in Patent Document 1 is configured to make it easy to obtain a three-dimensional effect in an image. However, depending on the device in which the non-contact switch is implemented, there may not be enough space to place the non-contact switch. For this reason, it is desirable to make the non-contact switch thinner.

Therefore, the present invention aims to provide a non-contact switch that can be made thinner.

As one embodiment of the present invention, there is provided a non-contact switch comprising: a light source, a light guide plate formed in a flat plate shape from a transparent member, having a first incident surface and a second incident surface, and capable of displaying a pattern indicating a position for accepting an operational input, a light source arranged to face the first incident surface, a detection unit arranged to face the second incident surface, emitting sensor light and outputting a detection signal indicating the detection when the sensor light reflected or scattered by a predetermined object at the position for accepting the operational input is detected, and a control unit which outputs a signal indicating that an operational input has been performed when the detection signal is received from the detection unit. The light guide plate has a plurality of first prisms that are arranged along a pattern indicating the position for accepting operation input on a first surface of the light guide plate opposite the position for accepting operation input, and that reflect light that is emitted from the light source and enters the light guide plate from the first entrance surface so as to exit from a second surface of the light guide plate on the side of the position for accepting operation input, and at least one second prism that is provided on the first surface of the light guide plate and reflects sensor light that is emitted from the detection unit and enters the light guide plate from the second entrance surface so as to exit from the second surface of the light guide plate toward the position for accepting operation input, and that is reflected or scattered by a predetermined object at that position and reflects the sensor light that enters the light guide plate from the second surface toward the detection unit.
With this configuration, the sensor light also propagates within the light guide plate for indicating the position where operational input is accepted, so there is no need to place the detection unit on the opposite side of the light guide plate from the position where operational input is accepted. As a result, the non-contact switch can be made thinner.

In this non-contact switch, it is preferable that the light guide plate has a plurality of second prisms provided on the first surface, and each of the plurality of second prisms is arranged so that the distance between the second prism and the position for accepting operational input is equal to each other.
By having such a configuration, this non-contact switch can approximately equalize the amount of sensor light that emits from the detection unit and reaches the position where the operational input is accepted, for each of the second prisms, and as a result, can accurately detect the operational input by the user regardless of the direction of the sensor light reflected or scattered by a specified object at the position where the operational input is accepted.

Alternatively, in this non-contact switch, it is preferable that the light guide plate has a plurality of second prisms provided on the first surface, and each of the plurality of second prisms is formed so that the reflective surface that reflects the sensor light becomes larger as the distance to the position where the operational input is accepted increases.
By having such a configuration, this non-contact switch can approximately equalize the amount of sensor light that emits from the detection unit and reaches the position where the operational input is accepted, for each of the second prisms, and as a result, can accurately detect the operational input by the user regardless of the direction of the sensor light reflected or scattered by a specified object at the position where the operational input is accepted.

Furthermore, in this non-contact switch, the first incident surface and the second incident surface are preferably provided on different side surfaces of the light guide plate.
By having such a configuration, this non-contact switch can prevent any of the first prisms from reflecting the sensor light toward the position where operational input is accepted, or can prevent any of the first prisms from reflecting sensor light reflected or scattered by an object at a position different from the position where operational input is accepted toward the detection unit, thereby preventing erroneous detection of operational input unintended by the user.

1 is a schematic configuration diagram of a non-contact switch according to an embodiment of the present invention; 2 is a schematic cross-sectional view of the light guide plate taken along the line indicated by the arrow AA' in FIG. 1 . 2 is a schematic cross-sectional view of the light guide plate taken along the line indicated by the arrow BB' in FIG. 1 . 13A is a schematic perspective view of a light guide plate according to a modified example, and FIG. 13B is a schematic front view of the light guide plate according to the modified example. FIG. 13 is a schematic configuration diagram of a non-contact switch according to another modified example.

The non-contact switch according to the embodiment of the present invention will be described below with reference to the drawings. In this non-contact switch, a plurality of prisms that reflect the light from the light source that enters the light guide plate from one of the entrance surfaces of the light guide plate and propagates through the light guide plate toward the side facing the user (hereinafter, for convenience of explanation, may be referred to as the front side) are arranged along a pattern that indicates the position where operation input is accepted, thereby making it possible to display the pattern. Furthermore, in this non-contact switch, the light emitting element and the light receiving element of the light sensor are arranged to face the other entrance surface of the light guide plate, and a prism that reflects the sensor light emitted from the light emitting element of the light sensor, enters the light guide plate, and propagates through the light guide plate toward the front side, and that reflects the sensor light that is reflected or scattered by the user's finger or the like and enters the light guide plate from the front side surface of the light guide plate toward the light receiving element of the light sensor is provided separately from the prism for forming the pattern. This allows the non-contact switch to be made thinner.

In the embodiment described below, the non-contact switch is operated by a user's finger. That is, the operational input is accepted by detecting sensor light reflected or scattered by a user's finger placed in a position to accept the operational input. A user's finger is an example of a predetermined object for making an operational input to a non-contact switch. However, the predetermined object for making an operational input is not limited to a user's finger, but may be another part of the user, such as the user's hand, or an object worn by or held by the user that can reflect or scatter the sensor light.

Figure 1 is a schematic diagram of a non-contact switch according to one embodiment of the present invention. The non-contact switch 1 has a light guide plate 11, a light source 12, an optical sensor 13, and a control unit 14. Each of these components is housed in a housing (not shown).

The light guide plate 11 is a member formed in a flat plate shape that is transparent to the light emitted from the light source 12 and the sensor light emitted from the light sensor 13. The light guide plate 11 is formed by molding a resin that is transparent to the light emitted from the light source 12 and the sensor light emitted from the light sensor 13, such as polymethyl methacrylate (PMMA), polycarbonate, or cycloolefin polymer. The light guide plate 11 displays a pattern 21 indicating a position where an operation input is accepted by the light emitted from the light source 12, entering the light guide plate 11, and propagating within the light guide plate 11. Furthermore, the light guide plate 11 directs the sensor light that is emitted from the light sensor 13, enters the light guide plate 11, and propagates within the light guide plate 11 to a position where an operation input is accepted, and directs the sensor light that is reflected or scattered by the user's finger placed at the position where the operation input is accepted and enters the light guide plate 11 to the light sensor 13.

2 is a schematic cross-sectional view of the light guide plate 11 along the line indicated by the arrow AA' in FIG. 1. FIG. 3 is a schematic cross-sectional view of the light guide plate 11 along the line indicated by the arrow BB' in FIG. 1. One of the side surfaces of the light guide plate 11 is formed as a first incident surface 11a through which light emitted from the light source 12 enters the light guide plate 11. In addition, a plurality of prisms 22 (first prisms) arranged along the pattern 21 are formed on the surface (first surface) on the rear side of the light guide plate 11. Each prism 22 is formed, for example, as a triangular prism-shaped groove, and is arranged so that one surface of the groove faces the light source 12 as an inclined surface. Each prism 22 enters the light guide plate 11 from the first incident surface 11a, totally reflects the light from the light source 12 propagating within the light guide plate 11, and emits the light from the front surface (second surface) of the light guide plate 11, thereby displaying the pattern 21. Pattern 21 is displayed near the position where operation input is accepted to indicate that position. For example, the display position of pattern 21 may be set so that the foot of a perpendicular line drawn from the position where operation input is accepted to the front surface of light guide plate 11 overlaps with pattern 21.

The pattern 21 may be displayed in the air on the front side of the light guide plate 11 as a three-dimensional image. In this case, a plurality of prisms 22 are provided for each point of the pattern 21. For each point of the pattern 21, each of the plurality of prisms 22 corresponding to that point is arranged so as to reflect the light incident from the incident surface 11a and propagating through the light guide plate 11 toward that point. Therefore, light from the plurality of prisms 22 arranged at different positions is concentrated on each point of the pattern 21, which is a three-dimensional image displayed in the air. Therefore, from the user positioned on the front side, it appears that light is emanating from each point of the pattern 21 displayed in the air. Therefore, the pattern 21 displayed in the air is observed from the user's perspective.

In addition, two or three of the side surfaces of the light guide plate 11 may be formed as first incident surfaces. Then, the light sources 12 may be arranged to face each of the first incident surfaces.

The other side of the light guide plate 11, which is perpendicular to the first incident surface 11a, is formed as a second incident surface 11b through which the sensor light emitted from the light sensor 13 enters the light guide plate 11. At least one prism 23 (second prism) is formed on the rear surface of the light guide plate 11. The prism 23 is formed, for example, as a triangular prism-shaped groove, and one surface of the groove is arranged as an inverted slope facing the light sensor 13. The prism 23 totally reflects the sensor light that enters from the second incident surface 11b and propagates through the light guide plate 11, and emits the light from the front surface of the light guide plate 11 toward the position where the operation input is accepted. Furthermore, the prism 23 totally reflects the sensor light that is reflected or scattered by the user's finger placed at the position where the operation input is accepted and enters the light guide plate 11 from the front surface of the light guide plate 11, and directs the light to the light sensor 13.

In this embodiment, the first incident surface 11a and the second incident surface 11b are perpendicular to each other, the light source 12 is provided so as to face the first incident surface 11a, and the light sensor 13 is provided so as to face the second incident surface 11b. Therefore, the reflecting surface of each prism 22 forming the pattern 21 and the reflecting surface of the prism 23 also face in different directions. Therefore, each prism 22 does not reflect the sensor light emitted from the light sensor 13 and passing through the entire light guide plate 11 toward the front side, and does not reflect the sensor light incident from the front surface of the light guide plate 11 toward the light sensor 13. Therefore, the sensor light is prevented from being reflected or scattered by an object placed at a position different from the position where the operation input is accepted and returning to the light sensor 13, so that the user's unintended operation input is prevented from being erroneously detected.

The two opposite sides of the light guide plate 11 may be formed as the first incident surface 11a and the second incident surface 11b, respectively. In this case, as in the above embodiment, each prism 22 does not reflect the sensor light emitted from the light sensor 13 and passing through the entire light guide plate 11 toward the front side, and does not reflect the sensor light incident from the front surface of the light guide plate 11 toward the light sensor 13, thereby preventing erroneous detection of an operation input that is not intended by the user.

Alternatively, a collimating lens may be disposed between the light source 12 and the optical sensor 13 and the side of the light guide plate 11 formed as the incident surface. In this case, the light emitted from the light source 12 and the sensor light emitted from the optical sensor 13 are each collimated and incident on the light guide plate 11, so that the light from the light source 12 and the sensor light from the optical sensor 13 propagate parallel to each other within the light guide plate 11. Therefore, in this case, each of the prisms 22 can be disposed in a position where the sensor light does not propagate, so that the first incident surface and the second incident surface can be the same side surface of the light guide plate 11.

The light source 12 emits light for displaying the pattern 21. To this end, the light source 12 has two or more light-emitting elements with different emission colors (for example, a first light-emitting element that emits blue light and a second light-emitting element that emits red light). That is, the light source 12 is capable of changing the emission color of the illumination light. Each light-emitting element can be, for example, a light-emitting diode. Each light-emitting element of the light source 12 is arranged so that its emission surface faces the first incidence surface 11a of the light guide plate 11. The light emitted from each light-emitting element of the light source 12 enters the light guide plate 11 from the first incidence surface 11a, propagates through the light guide plate 11, and is reflected by a plurality of prisms 22 provided on the back surface of the light guide plate 11, and is emitted from the front surface of the light guide plate 11 to display the pattern 21.

Each light-emitting element of the light source 12 is controlled in response to a control signal from the control unit 14 so that one of the light-emitting elements is turned on and the other light-emitting elements are turned off. That is, the color of the light that displays the pattern 21 changes depending on which of the light-emitting elements of the light source 12 is emitting light. Therefore, the control unit 14 switches which light-emitting element is turned on each time it receives an operational input from the user, making it easy for the user to identify the operational state of the non-contact switch 1.

The optical sensor 13 is an example of a detection unit, and detects an operational input by the user. To this end, the optical sensor 13 has a light-emitting element (not shown) that emits sensor light, and a light-receiving element (not shown) that detects the sensor light reflected or scattered by the user's finger and outputs a detection signal indicating that the sensor light has been detected. It is preferable that the sensor light is light that is not visible to the user, and therefore the light-emitting element can be, for example, an infrared-emitting diode that emits infrared light as the sensor light. In addition, the light-receiving element can be a light-receiving element that is sensitive to the sensor light, for example, a photodiode that is sensitive to infrared light.

In this embodiment, the optical sensor 13 is arranged so that the light emitting surface of the light emitting element and the light receiving surface of the light receiving element of the optical sensor 13 face the second incident surface 11b of the light guide plate 11. The sensor light emitted from the light emitting element of the optical sensor 13 enters the light guide plate 11 through the second incident surface 11b, propagates through the light guide plate 11, is totally reflected by the prism 23, exits from the front surface of the light guide plate 11, and heads toward the position where the operation input is accepted. When the user brings his/her finger close to the position where the operation input is accepted, a part of the sensor light reflected or scattered by the user's finger enters the light guide plate 11 from the front surface of the light guide plate 11 again, and is totally reflected by the prism 23 and returns to the optical sensor 13. When the light receiving element of the optical sensor 13 detects the returned sensor light, it outputs a detection signal to the control unit 14. This detects the operation input by the user. In this way, the light sensor 13 is arranged so that not only the light from the light source 12 for displaying the pattern 21 but also the sensor light propagates through the light guide plate 11, and a prism 23 is provided to reflect the sensor light to a position where operational input is accepted, thereby making it possible to make the non-contact switch 1 thinner. In this example, the path of the sensor light emitted from the light-emitting element and the path of the sensor light detected by the light-receiving element are approximately the same, so the position where operational input is accepted may be set on the path of the sensor light in the air on the front side of the light guide plate 11.

When the control unit 14 receives a detection signal from the light sensor 13, it outputs a signal indicating that an operation input has been performed, and changes the color of the illumination light emitted from the light source 12. To this end, the control unit 14 has, for example, one or more microprocessors, a semiconductor memory, and an interface for connecting to other devices.

When the control unit 14 does not accept an operational input from the user, it turns on one of the light-emitting elements of the light source 12 (for example, the first light-emitting element that emits blue light) and turns off the other light-emitting elements. This causes a pattern 21 having the emission color of the first light-emitting element to be displayed near the position where the operational input is accepted.

After that, when the control unit 14 receives a detection signal from the optical sensor 13, it outputs a signal to another device via the interface indicating that the operation state has become a first state (e.g., an on state). The control unit 14 then turns off the first light-emitting element of the light source 12 and turns on the other light-emitting element (e.g., a second light-emitting element that emits red light). This causes the color of the light displaying the pattern 21 to change (i.e., the color of the pattern changes from the emission color of the first light-emitting element to the emission color of the second light-emitting element). Therefore, the user can easily recognize that the operation input has been accepted and the operation state has changed.

Then, when the control unit 14 receives a detection signal again after temporarily stopping receiving the detection signal from the optical sensor 13, it outputs a signal to another device via the interface indicating that the operation state has become a second operation state (e.g., an off state). The control unit 14 then turns off the second light-emitting element and turns on the first light-emitting element among the light-emitting elements of the light source 12. This causes the color of the light displaying the pattern 21 to change from the emission color of the second light-emitting element to the emission color of the first light-emitting element. Therefore, the user can easily recognize that the operation input has been accepted again and the operation state has returned to the original state.

The control unit 14 may change the lighting state of the light source 12 other than the light emission color each time it receives a detection signal from the optical sensor 13. For example, the control unit 14 may blink the light source 12 at a predetermined cycle when it receives a detection signal from the optical sensor 13 and the operation state becomes the first operation state. The control unit 14 may then turn on the light source 12 when it stops receiving a detection signal from the optical sensor 13 and receives a detection signal again and the operation state becomes the second operation state. Alternatively, the control unit 14 may control the light source 12 so that the light emission intensity of the light source 12 differs when the operation state is the first operation state and when the operation state is the second operation state.

As described above, this non-contact switch can detect operational input by the user moving their finger to a position in the air where operational input is accepted, allowing the user to operate a device equipped with the non-contact switch without contact. In addition, this non-contact switch changes the display color of the pattern indicating the position where operational input is accepted each time operational input is accepted, allowing the user to easily determine whether or not operational input has been accepted. Furthermore, this non-contact switch has an optical sensor disposed within the light guide plate that displays the pattern indicating the position where operational input is accepted so that the sensor light also propagates within the light guide plate, eliminating the need to dispose an optical sensor on the back side of the light guide plate, and as a result, the non-contact switch can be made thinner.

According to a modified example, when multiple prisms 23 are formed on the light guide plate 11, it is preferable that each of the prisms 23 is positioned so that its reflective surface directly faces the light sensor 13.

4(a) is a schematic perspective view of the light guide plate 11 according to this modified example, and FIG. 4(b) is a schematic front view of the light guide plate 11 according to this modified example. In this modified example, a plurality of prisms 23 are formed on the rear surface of the light guide plate 11. Each prism 23 is arranged along an arc centered on the optical sensor 13. Each prism 23 is arranged so that the reflective surface of each prism 23 faces the optical sensor 13 directly. That is, for each prism 23, in a plane parallel to the rear surface of the light guide plate 11, the normal direction of the reflective surface of each prism 23 and the line connecting the optical sensor 13 and the reflective surface of the prism 23 are approximately parallel. In addition, each prism 23 is formed so that the inclination angle of the reflective surface of each prism 23 with respect to the rear surface of the light guide plate 11 is the same as each other. As a result, the sensor light emitted from the light sensor 13 and entering the light guide plate from the second entrance surface 11b is directed by the multiple prisms 23 toward a position P that is set on the front side of the light guide plate 11 and accepts operational input, making it possible to increase the amount of sensor light at position P. In addition, the sensor light reflected or scattered by the user's finger placed at position P that accepts operational input enters the light guide plate 11 from the front side surface of the light guide plate 11, and then is totally reflected by the multiple prisms 23 and heads toward the light sensor 13, making it possible to increase the amount of sensor light returning to the light sensor 13. Therefore, according to this modified example, the non-contact switch can detect operational input by the user with good sensitivity.

The multiple prisms 23 do not have to be arranged in a single arc centered on the optical sensor 13, and two or more of the multiple prisms 23 may be arranged so that the distance from the optical sensor 13 is different from each other. In this case, it is preferable that each of the prisms 23 is arranged so that the longer the distance from the optical sensor 13 to the prism 23, the greater the inclination angle of the reflecting surface of the prism 23 with respect to the rear surface of the light guide plate 11, so that the sensor light emitted from the optical sensor 13 and incident on the light guide plate 11 is totally reflected toward the same position P.

Furthermore, it is preferable that the multiple prisms 23 are arranged so that the distances from the prisms 23 to the position P where the operational input is accepted are equal to each other. This makes it possible to equalize the amount of sensor light emitted from the optical sensor 13 and directed toward the position P where the operational input is accepted, or the amount of sensor light returning to the optical sensor 13 from the position P where the operational input is accepted. As a result, this non-contact switch can accurately detect the operational input by the user, regardless of the direction of the sensor light reflected or scattered by the user's finger placed at the position where the operational input is accepted.

Alternatively, each of the multiple prisms 23 is preferably formed so that the reflective surface becomes larger as the distance from the prism 23 to the position P where the operational input is accepted increases. In this case, too, the amount of sensor light emitted from the optical sensor 13 and traveling toward the position P where the operational input is accepted, or the amount of sensor light returning to the optical sensor 13 from the position P where the operational input is accepted, can be made uniform for each prism 23. Therefore, in this case too, this non-contact switch can accurately detect the operational input by the user, regardless of the direction of the sensor light reflected or scattered by the user's finger placed at the position where the operational input is accepted.

According to another variation, the light emitting element and the light receiving element of the optical sensor may be positioned at different positions.

Figure 5 is a schematic diagram of a non-contact switch according to this modified example. The non-contact switch 2 according to this modified example differs from the non-contact switch 1 shown in Figure 1 in terms of the configuration of the optical sensor. Below, the differences and related parts of the non-contact switch 2 are explained. Also, in Figure 5, components that are not related to the differences are omitted from the illustration.

In this modified example, the light emitting element 131 and the light receiving element 132 of the optical sensor 13 are arranged to face the second incident surface 11b of the light guide plate 11 at different positions. For example, the light emitting element 131 and the light receiving element 132 are arranged so that a position for receiving an operation input is located between the light emitting element 131 and the light receiving element 132 in the direction along the second incident surface 11b of the light guide plate 11. The light emitting element 131 and the light receiving element 132 may be arranged to face different side surfaces of the light guide plate 11, or may be arranged to face each of the notches provided at two corners of the light guide plate 11. In this case, the side surface or notch facing the light emitting element 131 and the side surface or notch facing the light receiving element 132 are each another example of the second incident surface.

At least one prism 23-1 is provided on the rear surface of the light guide plate 11 to totally reflect the sensor light emitted from the light emitting element 131 of the optical sensor 13 and incident on the light guide plate 11 through the second incident surface 11b, and direct the sensor light to a position on the front side of the light guide plate 11 where operation input is accepted. At least one prism 23-2 is provided on the rear surface of the light guide plate 11 to totally reflect the sensor light that is reflected or scattered by the user's finger placed at the position where operation input is accepted and incident on the light guide plate 11 from the front surface of the light guide plate 11, and direct the sensor light to the light receiving element 132 of the optical sensor 13. In this example, the light emitting element 131 and the light receiving element 132 are arranged in the order of the light emitting element 131, the position where operation input is accepted, and the light receiving element 132 in the direction along the second incident surface 11b. Therefore, in order to direct the sensor light emitted from the light-emitting element 131 to the position where the operation input is received, each of the prisms 23-1 is provided so that the reflecting surface of the prism 23-1 rotates toward the light-receiving element 132 side in a plane parallel to the rear surface of the light guide plate 11 rather than the direction directly facing the light-emitting element 131. Conversely, in order to direct the sensor light from the position where the operation input is received to the light-receiving element 132, each of the prisms 23-2 is provided so that the reflecting surface of the prism 23-2 rotates toward the light-emitting element 131 side in a plane parallel to the rear surface of the light guide plate 11 rather than the direction directly facing the light-receiving element 132.

Like the non-contact switch according to the above embodiment, the non-contact switch according to this modified example is also thin because the light-emitting element and the light-receiving element of the optical sensor are arranged on the sides of the light guide plate.

Thus, those skilled in the art can make various modifications to suit the implementation form within the scope of the present invention.

Reference Signs List 1, 2 Non-contact switch 11 Light guide plate 11a First incident surface 11b Second incident surface 12 Light source 13 Optical sensor 131 Light emitting element 132 Light receiving element 21 Pattern 22 First prism 23, 23-1, 23-2 Second prism 14 Control unit

Claims (3)

A light source;
a light guide plate formed in a flat plate shape using a transparent member, the light guide plate having a first entrance surface and a second entrance surface, and capable of displaying a pattern indicating a position for receiving an operation input;
a light source disposed opposite the first incident surface;
a detection unit that is disposed to face the second incident surface, emits sensor light, and when it detects the sensor light reflected or scattered by a predetermined object located at a position where the operation input is received, outputs a detection signal indicating the detection;
a control unit that outputs a signal indicating that the operation input has been performed when the detection signal is received from the detection unit;
having
The light guide plate is
a plurality of first prisms that are arranged along the pattern on a first surface of the light guide plate opposite to a position where the operation input is accepted, and that reflect light that is emitted from the light source and enters the light guide plate from the first entrance surface so as to be emitted from a second surface of the light guide plate on the side of the position where the operation input is accepted;
a plurality of second prisms provided on the first surface of the light guide plate, the second prisms reflecting the sensor light emitted from the detection unit and incident into the light guide plate from the second incident surface, out of the second surface of the light guide plate, toward a position where the operation input is accepted, and reflecting the sensor light that is reflected or scattered by the predetermined object at the position and incident into the light guide plate from the second surface, toward the detection unit;
having
A non- contact switch, wherein each of the multiple second prisms is positioned such that the distances between the second prism and the position are equal to each other. A light source;
a light guide plate formed in a flat plate shape using a transparent member, the light guide plate having a first entrance surface and a second entrance surface, and capable of displaying a pattern indicating a position for receiving an operation input;
a light source disposed opposite the first incident surface;
a detection unit that is disposed to face the second incident surface, emits sensor light, and when it detects the sensor light reflected or scattered by a predetermined object located at a position where the operation input is received, outputs a detection signal indicating the detection;
a control unit that outputs a signal indicating that the operation input has been performed when the detection signal is received from the detection unit;
having
The light guide plate is
a plurality of first prisms that are arranged along the pattern on a first surface of the light guide plate opposite to a position where the operation input is accepted, and that reflect light that is emitted from the light source and enters the light guide plate from the first entrance surface so as to be emitted from a second surface of the light guide plate on the side of the position where the operation input is accepted;
a plurality of second prisms provided on the first surface of the light guide plate, the second prisms reflecting the sensor light emitted from the detection unit and incident into the light guide plate from the second incident surface, out of the second surface of the light guide plate, toward a position where the operation input is accepted, and reflecting the sensor light that is reflected or scattered by the predetermined object at the position and incident into the light guide plate from the second surface, toward the detection unit;
having
A non- contact switch, wherein each of the plurality of second prisms is formed so that the reflective surface that reflects the sensor light becomes larger as the distance to the position increases. The non-contact switch according to claim 1 , wherein the first incident surface and the second incident surface are provided on different side surfaces of the light guide plate.

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