JP2020187847A - Light receiving sensor, proximity sensor, and electronic apparatus - Google Patents

Abstract

To provide a light receiving sensor, a proximity sensor, and an electronic apparatus capable of enlarging a display area of the electronic apparatus and capable of increasing detection accuracy of the proximity sensor.SOLUTION: An electronic apparatus includes: a cover panel 91; a first circularly polarizing plate 41 disposed at a lower side of the cover panel 91; an OLED panel 5 disposed at a lower side of the first circularly polarizing plate 41; and a light emitting unit 10 and a light receiving sensor 98 disposed at a lower side of the OLED panel 5. The light emitting unit 10 includes an LED 21 and a second circularly polarizing plate 61 disposed at an upper side of the LED 21. The light receiving sensor 98 includes a light receiving element 34 and a third circularly polarizing plate 51 disposed at an upper side of the light receiving element 34. A polarization direction of the third circularly polarizing plate 51 is the same as a polarization direction of the second circularly polarizing plate 61. The polarization direction of the second circularly polarizing plate 61 and the polarization direction of the third circularly polarizing plate 51, and a polarization direction of the first circularly polarizing plate 41 are opposite to each other.SELECTED DRAWING: Figure 3

Description

The present invention relates to light receiving sensors, proximity sensors, and electronic devices.

Electronic devices such as smartphones are known to be equipped with a proximity sensor for detecting a nearby object. The proximity sensor detects the presence or absence of an object by emitting infrared light and detecting the infrared light reflected by the object.

In the electronic device of Patent Document 1, a proximity sensor is arranged in a bezel area around the electronic device.

Japanese Unexamined Patent Publication No. 2017-27595

In Patent Document 1, since it is necessary to provide an area for arranging the proximity sensor in the bezel area, the area of the bezel area becomes large. As a result, the display area of the electronic device becomes smaller. It is desired that the display area of the electronic device can be increased and the detection accuracy of the proximity sensor is high.

Therefore, an object of the present invention is to provide a light receiving sensor, a proximity sensor, and an electronic device capable of increasing the display area of the electronic device and increasing the detection accuracy of the proximity sensor. ..

The present invention is a light receiving sensor mounted on an electronic device. The electronic devices are arranged under the cover panel, the first circular polarizing plate arranged under the cover panel, the OLED panel arranged under the first circular polarizing plate, and the lower side of the OLED panel. It is provided with a light emitting unit. The light emitting unit includes an LED and a second circular polarizing plate arranged above the LED. The light receiving sensor includes a light receiving element and a third circular polarizing plate arranged above the light receiving element. The polarization direction of the second circular polarizing plate and the polarization direction of the third circular polarizing plate are the same. The polarization direction of the second circular polarizing plate, the polarization direction of the third circular polarizing plate, and the polarization direction of the first circular polarizing plate are opposite to each other.

Preferably, the first circular polarizing plate includes a first linear polarizing plate and a first 1/4 wave plate arranged below the first linear polarizing plate. The optical axis of the first quarter wave plate intersects the transmission axis of the first linear polarizing plate at an angle α. The second circularly polarizing plate includes a second linearly polarizing plate and a second 1/4 wave plate arranged above the second linearly polarizing plate. The optical axis of the second quarter wave plate intersects the transmission axis of the second linear polarizing plate at an angle β. The third circularly polarizing plate includes a third linear polarizing plate and a third quarter wave plate arranged above the third linear polarizing plate. The optical axis of the second quarter wave plate intersects the transmission axis of the second linear polarizing plate at an angle β. The magnitudes of α and β are the same, but the signs of α and β are different.

Preferably, α = −45 degrees and β = 45 degrees.
Preferably, α = 45 degrees and β = −45 degrees.

Preferably, the first circular polarizing plate is attached to the lower surface of the cover panel. The second circular polarizing plate is attached to the upper surface of the module containing the LED. The third circular polarizing plate is attached to the upper surface of the module including the light receiving element.

The present invention is a proximity sensor mounted on an electronic device. The electronic device includes a cover panel, a first circular polarizing plate arranged on the lower side of the cover panel, and an OLED panel arranged on the lower side of the first circular polarizing plate. The proximity sensor includes a light emitting unit arranged on the lower side of the OLED panel and a light receiving sensor arranged on the lower side of the OLED panel. The light emitting unit includes an LED and a second circular polarizing plate arranged above the LED. The light receiving sensor includes a light receiving element and a third circular polarizing plate arranged above the light receiving element. The polarization direction of the second circular polarizing plate and the polarization direction of the third circular polarizing plate are the same. The polarization direction of the second circular polarizing plate, the polarization direction of the third circular polarizing plate, and the polarization direction of the first circular polarizing plate are opposite to each other.

The electronic device of the present invention includes a cover panel, a first circular polarizing plate arranged under the cover panel, an OLED panel arranged under the first circular polarizing plate, and a lower side of the OLED panel. A light emitting unit arranged in the above and a light receiving sensor arranged under the OLED panel are provided. The light emitting unit includes an LED and a second circular polarizing plate arranged above the LED. The light receiving sensor includes a light receiving element and a third circular polarizing plate arranged above the light receiving element. The first circular polarizing plate is attached to the lower surface of the cover panel. The second circular polarizing plate is attached to the upper surface of the module containing the LED. The third circular polarizing plate is attached to the upper surface of the module including the light receiving element. The polarization direction of the second circular polarizing plate and the polarization direction of the third circular polarizing plate are the same. The polarization direction of the second circular polarizing plate, the polarization direction of the third circular polarizing plate, and the polarization direction of the first circular polarizing plate are opposite to each other.

The electronic device of the present invention includes a cover panel, a first circular polarizing plate arranged under the cover panel, an OLED panel arranged under the first circular polarizing plate, and a lower side of the OLED panel. A light emitting unit arranged in the above and a light receiving sensor arranged under the OLED panel are provided. The light emitting unit includes an LED. The light receiving sensor includes a light receiving element.

The electronic device further includes a second circular polarizing plate arranged on the upper side of the LED and a third circular polarizing plate arranged on the upper side of the light receiving element. The second circular polarizing plate is attached to the lower surface of the OLED panel. The third circular polarizing plate is attached to the lower surface of the OLED panel. The polarization direction of the second circular polarizing plate and the polarization direction of the third circular polarizing plate are the same. The polarization direction of the second circular polarizing plate, the polarization direction of the third circular polarizing plate, and the polarization direction of the first circular polarizing plate are opposite to each other.

According to the present invention, the display area of the electronic device can be increased, and the detection accuracy of the proximity sensor can be increased.

It is a figure which shows the main structure of the smartphone of embodiment. It is a figure which shows the structure of the proximity sensor 9 of an embodiment. It is a figure which shows the arrangement of the LED 21, the light receiving element 34, the OLED panel 5, the first circular polarizing plate 41, the second circular polarizing plate 61, and the third circular polarizing plate 51 in the 1st Embodiment. It is a figure which shows the path of the light incident from the outside. It is a figure which shows the path of the light emitted from LED21. It is a figure which shows the arrangement of the LED 21, the light receiving element 34, the OLED panel 5, the 1st circular polarizing plate 41, the 2nd circular polarizing plate 81, and the 3rd circular polarizing plate 71 in 2nd Embodiment. It is a figure which shows the arrangement of the LED 21, the light receiving element 34, the OLED panel 5, the 1st circular polarizing plate 41, the 2nd circular polarizing plate 81, and the 3rd circular polarizing plate 71 in the 3rd Embodiment. It is a figure which shows the arrangement of the LED 21, the light receiving element 34, the OLED panel 5, the first circular polarizing plate 141, the second circular polarizing plate 181 and the third circular polarizing plate 171 in the 4th embodiment. It is a figure which shows the arrangement of the LED 21, the light receiving element 34, the OLED panel 5, the 1st circular polarizing plate 241, the 2nd circular polarizing plate 261 and the 3rd circular polarizing plate 251 in 5th Embodiment.

Hereinafter, embodiments will be described with reference to the drawings.
In the following description, a smartphone will be described as an example of an electronic device, but the present invention is not limited to this, and includes a touch pad, a television, a camera, a music player, a mobile communication device other than the smartphone, and the like.

[First Embodiment]
FIG. 1 is a diagram showing a main configuration of a smartphone according to an embodiment.

The smartphone 100 includes an antenna 2, a wireless communication unit 3, a touch panel 4, an OLED (Organic Light Emitting Diode) panel 5, an illuminance sensor 6, a speaker 7, a microphone 8, a proximity sensor 9, and an acceleration sensor 16. The gyro sensor 17, the control circuit 12, and the battery 15 are provided. The proximity sensor 9 includes a light emitting unit 10 and a light receiving sensor 98. The control circuit 12 includes a processor 13 and a memory 14.

The antenna 2 transmits a radio signal to the base station and receives the radio signal from the base station.
The wireless communication unit 3 amplifies and downconverts the wireless signal sent from the antenna 2 and outputs it to the control circuit 12. The wireless communication unit 3 up-converts and amplifies a transmission signal including a sound signal generated by the control circuit 12, and outputs the processed wireless signal to the antenna 2.

The touch panel 4 detects the contact or proximity of an object such as a user's finger, and outputs a detection signal according to the detection result to the control circuit 12.

The microphone 8 converts the sound input from the outside of the smartphone 100 into an electrical sound signal and outputs it to the control circuit 12.

The speaker 7 converts an electrical sound signal from the control circuit 12 into sound and outputs it.
The acceleration sensor 16 detects the acceleration of the smartphone 100.

The gyro sensor 17 detects the rotation speed of the smartphone 100.
The OLED panel 5 displays various information such as characters, symbols, and figures under the control of the control circuit 12.

The illuminance sensor 6 detects the illuminance of the surrounding environment and outputs a detection signal according to the detection result to the control circuit 12.

The proximity sensor 9 detects the proximity of an object and outputs a detection signal according to the detection result to the control circuit 12. The control circuit 12 sets the touch panel 4 and the OLED panel 5 to the off state when the proximity of an object is detected.

The light emitting unit 10 emits infrared light.
The light receiving sensor 98 controls the emission of infrared light by the light emitting unit 10 and detects the infrared light emitted from the light emitting unit 10 and reflected by the object.

The processor 13 is composed of a CPU (Central Processing Unit), a DSP (Digital Signal Processing), and the like.

The memory 14 stores a control program for controlling the smartphone 100, a plurality of application programs, and the like. Various functions of the control circuit 12 are realized by the processor 13 executing various programs in the memory 14.

The battery 15 supplies electric power to the electronic components included in the smartphone 100.
FIG. 2 is a diagram showing the configuration of the proximity sensor 9 of the embodiment.

The light receiving sensor 98 includes a light receiving IC (Integrated Circuit) 11. The light receiving IC 11 includes a control logic 31, a pulse generator 32, a driving unit 39 including a driver 33, a light receiving element 34, an amplifier 35, and an ADC (Analog to Digital Converter) 36. The light emitting unit 10 includes an LED (Light Emitting Diode) 21.

The control logic 31 controls the drive of the LED 21 according to a command from the processor 13. The control logic 31 notifies the processor 13 of whether or not infrared light is received.

The pulse generator 32 outputs a pulse width modulation signal PWM.
The driver 33 drives the LED 21 according to the pulse width modulation signal PWM.

The light receiving element 34 detects the infrared light reflected by the object RF. The light receiving element 34 is composed of a photodiode.

The amplifier 35 amplifies the output signal of the light receiving element 34.
The ADC 36 converts the output signal of the amplifier 35 into a digital signal and outputs it to the control logic 31.

FIG. 3 is a diagram showing the arrangement of the LED 21, the light receiving element 34, the OLED panel 5, the first circular polarizing plate 41, the second circular polarizing plate 61, and the third circular polarizing plate 51 in the first embodiment. Is.

The longitudinal direction of the smartphone 100 is the Y-axis direction. The short side direction of the smartphone 100 is the X-axis. The normal direction of the front of the smartphone 100 is the Z-axis direction. In the following description, the lower side is the negative direction of the Z axis, and the upper side is the positive direction of the Z axis.

The first circular polarizing plate 41 is arranged below the cover panel 91. Specifically, the first circular polarizing plate 41 is attached to the lower surface of the cover panel 91.

The touch panel 4 is arranged below the first circular polarizing plate 41.
The OLED panel 5 is arranged below the touch panel 4.

On the lower side of the OLED panel 5, a proximity sensor 9 including a light emitting unit 10 and a light receiving sensor 98 is arranged on a main substrate 92.

The light emitting unit 10 includes a light emitting module 196 and a second circular polarizing plate 61.
The light emitting module 196 includes a base substrate 94, an LED 21, and a resin body 96.

The LED 21 is arranged on the base substrate 94. The resin body 96 protects the LED 21 from moisture and the atmosphere. The LED 21 is electrically connected to the main board 92 by connecting the main surface on the back side of the base board 94 to the main surface PM on the front side of the main board 92. A second circular polarizing plate 61 is attached to the upper surface of the light emitting module 196. That is, the second circular polarizing plate 61 is arranged on the upper side of the LED 21 via the resin body 96.

The light receiving sensor 98 includes a light receiving module 195 and a third circular polarizing plate 51. It includes a light receiving module 195, a base substrate 93, a light receiving IC 11, and a resin body 95.

The light receiving IC 11 is arranged on the base substrate 93. The light receiving IC 11 includes a light receiving element 34. The resin body 95 protects the light receiving IC 11 from moisture and the atmosphere. The light receiving IC 11 is electrically connected to the main board 92 by connecting the main surface on the back side of the base board 93 to the main surface PM on the front side of the main board 92. A third circular polarizing plate 51 is attached to the upper surface of the light receiving module 195. That is, the third circular polarizing plate 51 is arranged on the upper side of the light receiving element 34 via the resin body 95.

The polarization direction of the second circular polarizing plate 61 and the polarization direction of the third circular polarizing plate 51 are the same. The polarization direction of the second circular polarizing plate 61, the polarization direction of the third circular polarizing plate 51, and the polarization direction of the first circular polarizing plate 41 are opposite to each other.

The first circular polarizing plate 41 includes a first linear polarizing plate 42 and a first quarter wave plate 43. The first quarter wave plate 43 is arranged below the first linear polarizing plate 42. The transmission axis of the first linear polarizing plate 42 is the X-axis direction. The optical axis of the first quarter wave plate 43 intersects the transmission axis (X axis) of the first linear polarizing plate 42 at an angle of α (= 45 degrees).

The second circular polarizing plate 61 includes a second linear polarizing plate 63 and a second 1/4 wave plate 62. The second 1/4 wave plate 62 is arranged above the second linear polarizing plate 63. The transmission axis of the second linear polarizing plate 63 is the X-axis direction. The angle formed by the optical axis of the second linear polarizing plate 63 and the optical axis of the second quarter wave plate 62 is β (= −45 degrees).

The third circular polarizing plate 51 includes a third linear polarizing plate 53 and a third quarter wave plate 52. The third quarter wave plate 52 is arranged above the third linear polarizing plate 53. The transmission axis of the third linear polarizing plate 53 is the X-axis direction. The angle formed by the optical axis of the third linear polarizing plate 53 and the optical axis of the third quarter wave plate 52 is β (−45 degrees).

FIG. 4 is a diagram showing a path of light incident from the outside.
Light from the outside is incident on the first linear polarizing plate 42 via the cover panel 91.

Light that oscillates in the X-axis direction is emitted from the first linear polarizing plate 42 and is incident on the first quarter wave plate 43.

Light rotating in the second direction (counterclockwise) is emitted from the first 1/4 wave plate 43, and is incident on the OLED panel 5 via the touch panel 4. The light reflected by the OLED panel 5 passes through the touch panel 4 and is incident on the first quarter wave plate 43.

From the first 1/4 wave plate 43, the phase difference between the two 1/4 wave plates is added, and light vibrating in the direction perpendicular to the X-axis direction is emitted to the first linear polarizing plate 42. Be incidented. The first linear polarizing plate 42 does not transmit the incident light. As a result, the light incident from the outside does not return to the outside. This can prevent the contrast of the OLED panel 5 from being reduced.

FIG. 5 is a diagram showing a path of light emitted from the LED 21.
The light paths (1) to (7) shown in FIG. 5 will be described.

(1) Paths (1) and (2) The light emitted from the LED 21 is incident on the second linear polarizing plate 63. Light that oscillates in the X-axis direction is emitted from the second linear polarizing plate 63 and is incident on the second quarter wave plate 62. Light rotating in the first direction (clockwise) is emitted from the second 1/4 wave plate 62, passes through the OLED panel 5 and the touch panel 4, and is incident on the first 1/4 wave plate 43. From the first 1/4 wave plate 43, the phase difference between the two 1/4 wave plates is canceled out, and light oscillating in the X-axis direction is emitted and incident on the first linear polarizing plate 42. ..

Light vibrating in the X-axis direction is emitted from the first linear polarizing plate 42. The light emitted from the first linear polarizing plate 42 that vibrates in the X-axis direction is reflected by the upper surface of the cover panel 91 (path (2)), or is reflected by the object RF via the cover panel 91. (Route (1)). The reflected light oscillating in the X-axis direction passes through the cover panel 91 and is incident on the first linear polarizing plate 42. Light that oscillates in the X-axis direction is emitted from the first linear polarizing plate 42 and is incident on the first quarter wave plate 43.

Light rotating in the second direction (counterclockwise) is emitted from the first 1/4 wave plate 43, passes through the touch panel 4 and the OLED panel 5, and is incident on the third 1/4 wave plate 52. From the third 1/4 wave plate 52, the phase difference between the two 1/4 wave plates is canceled out, and light oscillating in the X-axis direction is emitted and incident on the third linear polarizing plate 53. .. Light vibrating in the X-axis direction is emitted from the third linear polarizing plate 53 and is incident on the light receiving element 34. As a result, the light following the paths (1) and (2) is incident on the light receiving element 34. In FIG. 5, since the light following the path (2) is not reflected by the object RF, the light following the path (2) is not used for detecting the proximity of the object RF. However, when the object RF comes into contact with the cover panel 91, if there is no path (2), the proximity of the object RF cannot be detected. Therefore, the route (2) is a necessary route. Further, since the object RF does not exist, when there is no light following the path (1), the intensity of the light detected by the light receiving element 34 for the light following the path (2) is set to I1, and the object RF is transferred to the cover panel 91. When there is no light that follows the path (1) due to contact, I2> I1 when the intensity of the light that is detected by the light receiving element 34 for the light that follows the path (2) is I2. Therefore, even when the object RF comes into contact with the cover panel 91, the proximity of the object RF can be detected.

(2) Paths (3) to (7) The light emitted from the LED 21 is incident on the second linear polarizing plate 63. Light that oscillates in the X-axis direction is emitted from the second linear polarizing plate 63 and is incident on the second quarter wave plate 62. Light rotating in the first direction (clockwise) is emitted from the second quarter wave plate 62. The light emitted from the second 1/4 wave plate 62 and rotating in the first direction (clockwise) is the lower surface (path (3)) of the first 1/4 wave plate 43, the touch panel 4. The upper surface (path (4)), the lower surface of the touch panel 4 (path (5)), the upper surface of the OLED panel 5 (path (6)), and the lower surface of the OLED panel 5 (path (path (5)). 7)) is reflected. The reflected light rotating in the first direction (clockwise) is incident on the third quarter wave plate 52.

From the third 1/4 wave plate 52, the phase difference between the two 1/4 wave plates is added, and light vibrating in the direction perpendicular to the X-axis direction is emitted to the third linear polarizing plate 53. Being incident. The third linear polarizing plate 53 does not transmit the incident light. As a result, the light following the path (3) is not incident on the light receiving element 34. Therefore, it is possible to prevent erroneous detection of the proximity of the object RF.

As described above, according to the present embodiment, the area of the bezel can be reduced by using the OLED panel as the display panel and arranging the proximity sensor under the OLED panel. As a result, the area of the OLED panel can be increased.

Further, according to the present embodiment, the first circular polarizing plate can prevent the light from the outside from being reflected by the OLED panel. Further, according to the present embodiment, the light emitted from the LED is reflected by the internal touch panel, the OLED panel, etc. by the first circular polarizing plate, the second circular polarizing plate, and the third circular polarizing plate. It is possible to prevent the detection accuracy of the proximity of the object from being deteriorated by being incident on the light receiving element.

[Second Embodiment]
FIG. 6 is a diagram showing the arrangement of the LED 21, the light receiving element 34, the OLED panel 5, the first circular polarizing plate 41, the second circular polarizing plate 81, and the third circular polarizing plate 71 in the second embodiment. Is. The arrangement of the second embodiment of FIG. 6 is different from the arrangement of the first embodiment of FIG. 3 as follows.

The light emitting unit 10 does not include a second circular polarizing plate attached to the upper surface of the light emitting module 196. The light receiving sensor 98 does not include a third circular polarizing plate attached to the upper surface of the light receiving module 195.

The smartphone of the second embodiment is the upper side of the LED 21, the second circular polarizing plate 81 attached to the lower surface of the OLED panel 5, and the upper side of the light receiving element 34, which is the OLED panel 5. It is provided with a third circular polarizing plate 71 attached to the lower surface.

The polarization direction of the second circular polarizing plate 81 and the polarization direction of the third circular polarizing plate 71 are the same. The polarization direction of the second circular polarizing plate 81, the polarization direction of the third circular polarizing plate 71, and the polarization direction of the first circular polarizing plate 41 are opposite to each other.

The second circular polarizing plate 81 includes a second linear polarizing plate 83 and a second 1/4 wave plate 82. The second quarter wave plate 82 is arranged above the second linear polarizing plate 83. The transmission axis of the second linear polarizing plate 83 is the X-axis direction. The angle formed by the optical axis of the second linear polarizing plate 83 and the optical axis of the second quarter wave plate 82 is β (= −45 degrees).

The third circular polarizing plate 71 includes a third linear polarizing plate 73 and a third quarter wave plate 72. The third quarter wave plate 72 is arranged above the third linear polarizing plate 73. The transmission axis of the third linear polarizing plate 73 is the X-axis direction. The angle formed by the optical axis of the third linear polarizing plate 73 and the optical axis of the third quarter wave plate 72 is β (−45 degrees).

Next, the light paths (1) to (7) shown in FIG. 6 will be described.
(1) Paths (1) and (2) The light emitted from the LED 21 is incident on the second linear polarizing plate 83. Light that oscillates in the X-axis direction is emitted from the second linear polarizing plate 83 and is incident on the second quarter wave plate 82. Light rotating in the first direction (clockwise) is emitted from the second 1/4 wave plate 82, passes through the OLED panel 5 and the touch panel 4, and is incident on the first 1/4 wave plate 43. From the first 1/4 wave plate 43, the phase difference between the two 1/4 wave plates is canceled out, and light oscillating in the X-axis direction is emitted and incident on the first linear polarizing plate 42. ..

Light vibrating in the X-axis direction is emitted from the first linear polarizing plate 42. The light emitted from the first linear polarizing plate 42 that vibrates in the X-axis direction is reflected by the upper surface of the cover panel 91 (path (2)), or is reflected by the object RF via the cover panel 91. (Route (1)). The reflected light oscillating in the X-axis direction passes through the cover panel 91 and is incident on the first linear polarizing plate 42.

Light that oscillates in the X-axis direction is emitted from the first linear polarizing plate 42 and is incident on the first quarter wave plate 43. Light rotating in the second direction (counterclockwise) is emitted from the first 1/4 wave plate 43, passes through the touch panel 4 and the OLED panel 5, and is incident on the third 1/4 wave plate 72. From the third 1/4 wave plate 72, the phase difference between the two 1/4 wave plates is canceled out, and light oscillating in the X-axis direction is emitted and incident on the third linear polarizing plate 73. .. Light vibrating in the X-axis direction is emitted from the third linear polarizing plate 73 and is incident on the light receiving element 34. As a result, the light following the paths (1) and (2) is incident on the light receiving element 34.

(2) Paths (3) to (7) The light emitted from the LED 21 is incident on the second linear polarizing plate 83. Light that oscillates in the X-axis direction is emitted from the second linear polarizing plate 83 and is incident on the second quarter wave plate 82. Light rotating in the first direction (clockwise) is emitted from the second quarter wave plate 82. The light emitted from the second 1/4 wave plate 82 and rotating in the first direction (clockwise) is the lower surface (path (3)) of the first 1/4 wave plate 43, the touch panel 4. The upper surface (path (4)), the lower surface of the touch panel 4 (path (5)), the upper surface of the OLED panel 5 (path (6)), and the lower surface of the OLED panel 5 (path (path (5)). 7)) is reflected. The reflected light rotating in the first direction (clockwise) is incident on the third quarter wave plate 72.

From the third 1/4 wave plate 72, the phase difference between the two 1/4 wave plates is added, and light vibrating in the direction perpendicular to the X-axis direction is emitted to the third linear polarizing plate 73. Being incident. The third linear polarizing plate 73 does not transmit the incident light. As a result, the light following the path (3) is not incident on the light receiving element 34. Therefore, it is possible to prevent erroneous detection of the proximity of the object RF.

The same effect as that of the first embodiment can be obtained in the second embodiment.
[Third Embodiment]
FIG. 7 is a diagram showing the arrangement of the LED 21, the light receiving element 34, the OLED panel 5, the first circular polarizing plate 41, the second circular polarizing plate 81, and the third circular polarizing plate 71 in the third embodiment. Is.

The arrangement of the third embodiment of FIG. 7 is different from the arrangement of the first embodiment of FIG. 3 as follows. In the third embodiment, instead of the first circular polarizing plate 41, the second circular polarizing plate 61, and the third circular polarizing plate 51, the first circular polarizing plate 141 and the second circular polarizing plate 161 , And a third circular polarizing plate 151.

The first circular polarizing plate 141 is arranged under the cover panel 91. Specifically, the first circular polarizing plate 141 is attached to the lower surface of the cover panel 91.

A second circular polarizing plate 161 is attached to the upper surface of the light emitting module 196. That is, the second circular polarizing plate 161 is arranged on the upper side of the LED 21 via the resin body 96. A third circular polarizing plate 151 is attached to the upper surface of the light receiving module 195. That is, the third circular polarizing plate 151 is arranged on the upper side of the light receiving element 34 via the resin body 95.

The polarization direction of the second circular polarizing plate 161 and the polarization direction of the third circular polarizing plate 151 are the same. The polarization direction of the second circular polarizing plate 161 and the polarization direction of the third circular polarizing plate 151 and the polarization direction of the first circular polarizing plate 41 are opposite to each other.

The first circular polarizing plate 41 includes a first linear polarizing plate 42 and a first quarter wave plate 143. The first quarter wave plate 143 is arranged below the first linear polarizing plate 42. The transmission axis of the first linear polarizing plate 42 is the X-axis direction. The optical axis of the first quarter wave plate 143 intersects the transmission axis (X axis) of the first linear polarizing plate 42 at an angle of α (= −45 degrees).

The second circular polarizing plate 161 includes a second linear polarizing plate 63 and a second 1/4 wave plate 162. The second quarter wave plate 162 is arranged above the second linear polarizing plate 63. The transmission axis of the second linear polarizing plate 63 is the X-axis direction. The angle formed by the optical axis of the second linear polarizing plate 63 and the optical axis of the second quarter wave plate 162 is β (= 45 degrees).

The third circular polarizing plate 151 includes a third linear polarizing plate 53 and a third quarter wave plate 152. The third quarter wave plate 152 is arranged above the third linear polarizing plate 53. The transmission axis of the third linear polarizing plate 53 is the X-axis direction. The angle formed by the optical axis of the third linear polarizing plate 53 and the optical axis of the third quarter wave plate 152 is β (45 degrees).

The light paths (1) to (7) shown in FIG. 7 will be described.
(1) Paths (1) and (2) The light emitted from the LED 21 is incident on the second linear polarizing plate 63. Light oscillating in the X-axis direction is emitted from the second linear polarizing plate 63 and is incident on the second quarter wave plate 162. Light rotating in the second direction (counterclockwise) is emitted from the second 1/4 wave plate 162, and is incident on the first 1/4 wave plate 143 via the OLED panel 5 and the touch panel 4. From the first 1/4 wave plate 143, the phase difference between the two 1/4 wave plates is canceled out, and light oscillating in the X-axis direction is emitted and incident on the first linear polarizing plate 42. ..

Light vibrating in the X-axis direction is emitted from the first linear polarizing plate 42. The light emitted from the first linear polarizing plate 42 that vibrates in the X-axis direction is reflected by the upper surface of the cover panel 91 (path (2)), or is reflected by the object RF via the cover panel 91. (Route (1)). The reflected light oscillating in the X-axis direction passes through the cover panel 91 and is incident on the first linear polarizing plate 42.

Light vibrating in the X-axis direction is emitted from the first linear polarizing plate 42 and is incident on the first quarter wave plate 143. Light rotating in the first direction (clockwise) is emitted from the first 1/4 wave plate 143, passes through the touch panel 4 and the OLED panel 5, and is incident on the third 1/4 wave plate 152. From the third 1/4 wave plate 152, the phase difference between the two 1/4 wave plates is canceled out, and light oscillating in the X-axis direction is emitted and incident on the third linear polarizing plate 53. .. Light vibrating in the X-axis direction is emitted from the third linear polarizing plate 53 and is incident on the light receiving element 34. As a result, the light following the paths (1) and (2) is incident on the light receiving element 34. As a result, the light following the paths (1) and (2) is incident on the light receiving element 34.

(2) Paths (3) to (7) The light emitted from the LED 21 is incident on the second linear polarizing plate 63. Light oscillating in the X-axis direction is emitted from the second linear polarizing plate 63 and is incident on the second quarter wave plate 162. Light rotating in the second direction (counterclockwise) is emitted from the second quarter wave plate 162. The light emitted from the second 1/4 wave plate 162 and rotating in the second direction (counterclockwise) is the lower surface (path (3)) of the first 1/4 wave plate 143, the touch panel 4. The upper surface (path (4)), the lower surface of the touch panel 4 (path (5)), the upper surface of the OLED panel 5 (path (6)), and the lower surface of the OLED panel 5 (path (path (5)). 7)) is reflected. The reflected light rotating in the second direction (counterclockwise) is incident on the third quarter wave plate 152.

From the third 1/4 wave plate 152, the phase difference between the two 1/4 wave plates is added, and light vibrating in the direction perpendicular to the X-axis direction is emitted to the third linear polarizing plate 53. Being incident. The third linear polarizing plate 53 does not transmit the incident light. As a result, the light following the paths (3) to (7) is not incident on the light receiving element 34. Therefore, it is possible to prevent erroneous detection of the proximity of the object RF.

The same effect as that of the first embodiment can be obtained in the third embodiment.
[Fourth Embodiment]
FIG. 8 is a diagram showing the arrangement of the LED 21, the light receiving element 34, the OLED panel 5, the first circular polarizing plate 141, the second circular polarizing plate 181 and the third circular polarizing plate 171 in the fourth embodiment. Is. The arrangement of the fourth embodiment of FIG. 8 is different from the arrangement of the third embodiment of FIG. 7 as follows.

The light emitting unit 10 does not include a second circular polarizing plate attached to the upper surface of the light emitting module 196. The light receiving sensor 98 does not include a third circular polarizing plate attached to the upper surface of the light receiving module 195.

The smartphone of the fourth embodiment is the upper side of the LED 21, the second circular polarizing plate 181 attached to the lower surface of the OLED panel 5, and the upper side of the light receiving element 34, and is the OLED panel 5. It is provided with a third circular polarizing plate 171 attached to the lower surface.

The polarization direction of the second circular polarizing plate 181 and the polarization direction of the third circular polarizing plate 171 are the same. The polarization direction of the second circular polarizing plate 181 and the polarization direction of the third circular polarizing plate 171 and the polarization direction of the first circular polarizing plate 141 are opposite to each other.

The second circular polarizing plate 181 includes a second linear polarizing plate 83 and a second 1/4 wave plate 182. The second quarter wave plate 182 is arranged above the second linear polarizing plate 83. The transmission axis of the second linear polarizing plate 83 is the X-axis direction. The angle formed by the optical axis of the second linear polarizing plate 83 and the optical axis of the second quarter wave plate 182 is β (= 45 degrees).

The third circular polarizing plate 171 includes a third linear polarizing plate 73 and a third quarter wave plate 172. The third quarter wave plate 172 is arranged above the third linear polarizing plate 73. The transmission axis of the third linear polarizing plate 73 is the X-axis direction. The angle formed by the optical axis of the third linear polarizing plate 73 and the optical axis of the third quarter wave plate 172 is β (45 degrees).

The light paths (1) to (7) shown in FIG. 8 will be described.
(1) Paths (1) and (2) The light emitted from the LED 21 is incident on the second linear polarizing plate 83. Light oscillating in the X-axis direction is emitted from the second linear polarizing plate 83 and is incident on the second quarter wave plate 182. Light rotating in the second direction (counterclockwise) is emitted from the second 1/4 wave plate 182, and is incident on the first 1/4 wave plate 143 via the OLED panel 5 and the touch panel 4. From the first 1/4 wave plate 143, the phase difference between the two 1/4 wave plates is canceled out, and light oscillating in the X-axis direction is emitted and incident on the first linear polarizing plate 42. ..

Light vibrating in the X-axis direction is emitted from the first linear polarizing plate 42. The light emitted from the first linear polarizing plate 42 that vibrates in the X-axis direction is reflected by the upper surface of the cover panel 91 (path (2)), or is reflected by the object RF via the cover panel 91. (Route (1)). The reflected light oscillating in the X-axis direction passes through the cover panel 91 and is incident on the first linear polarizing plate 42.

Light vibrating in the X-axis direction is emitted from the first linear polarizing plate 42 and is incident on the first quarter wave plate 143. Light rotating in the first direction (clockwise) is emitted from the first 1/4 wave plate 143, passes through the touch panel 4 and the OLED panel 5, and is incident on the third 1/4 wave plate 172. From the third 1/4 wave plate 172, the phase difference between the two 1/4 wave plates is canceled out, and light oscillating in the X-axis direction is emitted and incident on the third linear polarizing plate 73. .. Light vibrating in the X-axis direction is emitted from the third linear polarizing plate 73 and is incident on the light receiving element 34. As a result, the light following the paths (1) and (2) is incident on the light receiving element 34.

(2) Paths (3) to (7) The light emitted from the LED 21 is incident on the second linear polarizing plate 83. Light oscillating in the X-axis direction is emitted from the second linear polarizing plate 83 and is incident on the second quarter wave plate 182. Light rotating in the second direction (counterclockwise) is emitted from the second quarter wave plate 182. The light emitted from the second 1/4 wave plate 182 and rotating in the second direction (counterclockwise) is the lower surface (path (3)) of the first 1/4 wave plate 143, the touch panel 4. The upper surface (path (4)), the lower surface of the touch panel 4 (path (5)), the upper surface of the OLED panel 5 (path (6)), and the lower surface of the OLED panel 5 (path (path (5)). 7)) is reflected. The reflected light rotating in the second direction (counterclockwise) is incident on the third quarter wave plate 172.

From the third 1/4 wave plate 172, the phase difference between the two 1/4 wave plates is added, and light vibrating in the direction perpendicular to the X-axis direction is emitted to the third linear polarizing plate 73. Being incident. The third linear polarizing plate 73 does not transmit the incident light. As a result, the light following the path (3) is not incident on the light receiving element 34. Therefore, it is possible to prevent erroneous detection of the proximity of the object RF.

The same effect as that of the first embodiment can be obtained in the fourth embodiment.
[Fifth Embodiment]
FIG. 9 is a diagram showing the arrangement of the LED 21, the light receiving element 34, the OLED panel 5, the first circular polarizing plate 241 and the second circular polarizing plate 261 and the third circular polarizing plate 251 in the fifth embodiment. Is.

The arrangement of the fifth embodiment of FIG. 9 is different from the arrangement of the first embodiment of FIG. 3 as follows.

The first circular polarizing plate 241 includes a first 1/2 wave plate 244 between the first 1/4 wave plate 43 and the first linear polarizing plate 42. The second circular polarizing plate 261 includes a second 1/2 wavelength plate 264 between the second 1/4 wave plate 62 and the second linear polarizing plate 63. The third circular polarizing plate 251 includes a third 1/2 wavelength plate 254 between the third 1/4 wave plate 52 and the third linear polarizing plate 53.

The quarter wave plates 43, 62, and 53 have a characteristic that the shorter the wavelength, the larger the phase difference. In the present embodiment, the circular polarizing plates 241, 261, and 251 are provided with 1/2 wave plates 244, 264, and 254 in order to prevent the phase difference from changing depending on the wavelength.

Since the light is rotated by 180 degrees by the 1/2 wave plates 244, 264, and 254, the light paths (1) to (7) of the present embodiment are the light paths of the first embodiment shown in FIG. Is similar to.

Similarly, in the smartphones of the second to fourth embodiments, the first, second, and third circular polarizing plates are placed between the 1/4 wave plate and the linear polarizing plate, respectively. It may be provided with a two-wave plate.

The same effect as that of the first embodiment can be obtained in the fifth embodiment. Further, in the fifth embodiment, the accuracy of the proximity detection function of the object and the antireflection function of the light from the outside can be improved by adding three 1/2 wavelength plates.

(Modification example)
The present invention is not limited to the above embodiment, and includes, for example, the following modifications.

(1) In the above embodiment, the angle formed by the optical axis of the first linear polarizing plate and the optical axis of the first 1/4 wave plate is 45 degrees or (−45) degrees, and the second The angle between the optical axis of the linear polarizing plate and the optical axis of the second 1/4 wave plate is (-45) degrees or 45 degrees, and the optical axis of the third linear polarizing plate and the third 1 / The angle formed by the four-wave plate with the optical axis is (-45 degrees) or 45 degrees, but the angle is not limited to this.

Let α be the angle formed by the optical axis of the first linear polarizing plate and the optical axis of the first 1/4 wave plate, and the optical axis of the second linear polarizing plate and the optical axis of the second 1/4 wave plate. Let β be the angle between and β, and let β be the angle between the optical axis of the third linear polarizing plate and the optical axis of the third 1/4 wave plate, and the magnitudes of α and β are equal, and α and β The symbols may be different.

When the magnitudes of α and β are 45 degrees, circularly polarized light is incident or emitted on the 1/4 wavelength plate. When the magnitudes of α and β are other than 45 degrees, elliptically polarized light is incident or emitted on the 1/4 wavelength plate.

(2) In the above embodiment, the smartphone includes an illuminance sensor and a light receiving sensor of a proximity sensor, but the smartphone is not limited thereto. One light receiving sensor may perform both illuminance detection and proximity detection.

(3) The number of LEDs is not limited to one. The proximity sensor may include two or more LEDs.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

2 antenna, 3 wireless communication unit, 4 touch panel, 5 OLED panel, 6 illuminance sensor, 7 speaker, 8 microphone, 9 proximity sensor, 10 light emitting unit, 11 light receiving IC, 12 control circuit, 13 processor, 14 memory, 15 battery, 16 acceleration sensor, 17 gyro sensor, 21 LED, 31 control logic, 32 pulse generator, 33 driver, 34 light receiving element, 35 amplifier, 36 ADC, 41,141,241 first circularly polarizing plate, 61,81,161 , 181,261 2nd circularly polarizing plate, 51,71,151,171,251 3rd circularly polarizing plate, 42 1st linearly polarizing plate, 63,83 2nd linearly polarizing plate, 53,73 3rd Linearly polarizing plate, 43,143 first 1/4 wave plate, 62,82,162,182 second 1/4 wave plate, 52,72,152,172 third 1/4 wave plate, 91 Cover panel, 92 main board, 93,94 base board, 95,96 resin body, 98 light receiving sensor, 100 smartphone, 195 light receiving module, 196 light emitting module, 244 1st 1/2 wave plate 254 3rd 1/2 Wave plate, 264 Second 1/2 wave plate, RF object.

Claims (8)

It is a light receiving sensor installed in electronic devices.
The electronic device includes a cover panel, a first circular polarizing plate arranged under the cover panel, an OLED panel arranged under the first circular polarizing plate, and under the OLED panel. The light emitting unit includes a light emitting unit arranged on the side, and the light emitting unit includes an LED and a second circular polarizing plate arranged on the upper side of the LED.
The light receiving sensor is
With the light receiving element
A third circular polarizing plate arranged on the upper side of the light receiving element is provided.
The polarization direction of the second circular polarizing plate and the polarization direction of the third circular polarizing plate are the same.
A light receiving sensor in which the polarization direction of the second circular polarizing plate, the polarization direction of the third circular polarizing plate, and the polarization direction of the first circular polarizing plate are opposite to each other. The first circular polarizing plate is
The first linear polarizing plate and
It includes a first quarter wave plate arranged below the first linear polarizing plate.
The optical axis of the first quarter wave plate intersects the transmission axis of the first linear polarizing plate at an angle α.
The second circular polarizing plate is
The second linear polarizing plate and
It includes a second quarter wave plate arranged above the second linear polarizing plate.
The optical axis of the second 1/4 wave plate intersects the transmission axis of the second linear polarizing plate at an angle β.
The third circular polarizing plate is
With the third linear polarizing plate,
Including a third quarter wave plate arranged above the third linear polarizing plate.
The optical axis of the second 1/4 wave plate intersects the transmission axis of the second linear polarizing plate at an angle β.
The light receiving sensor according to claim 1, wherein the magnitudes of α and β are the same, and the symbols of α and β are different. The light receiving sensor according to claim 2, wherein α = −45 degrees and β = 45 degrees. The light receiving sensor according to claim 2, wherein α = 45 degrees and β = −45 degrees. The second circular polarizing plate is attached to the upper surface of the module containing the LED.
The light receiving sensor according to claim 1, wherein the third circular polarizing plate is attached to the upper surface of a module including the light receiving element. Proximity sensor mounted on electronic devices
The electronic device includes a cover panel, a first circular polarizing plate arranged under the cover panel, and an OLED panel arranged under the first circular polarizing plate.
The proximity sensor is
A light emitting unit arranged under the OLED panel and
A light receiving sensor arranged under the OLED panel is provided.
The light emitting unit
LED and
Including a second circular polarizing plate arranged above the LED.
The light receiving sensor is
With the light receiving element
Including a third circular polarizing plate arranged above the light receiving element,
The polarization direction of the second circular polarizing plate and the polarization direction of the third circular polarizing plate are the same.
A proximity sensor in which the polarization direction of the second circular polarizing plate, the polarization direction of the third circular polarizing plate, and the polarization direction of the first circular polarizing plate are opposite to each other. Cover panel and
A first circular polarizing plate arranged under the cover panel and
An OLED panel arranged under the first circular polarizing plate and
A light emitting unit arranged under the OLED panel and
A light receiving sensor arranged under the OLED panel is provided.
The light emitting unit
LED and
Including a second circular polarizing plate arranged above the LED.
The light receiving sensor is
With the light receiving element
Including a third circular polarizing plate arranged above the light receiving element,
The first circular polarizing plate is attached to the lower surface of the cover panel.
The second circular polarizing plate is attached to the upper surface of the module containing the LED.
The third circular polarizing plate is attached to the upper surface of the module containing the light receiving element.
The polarization direction of the second circular polarizing plate and the polarization direction of the third circular polarizing plate are the same.
An electronic device in which the polarization direction of the second circular polarizing plate, the polarization direction of the third circular polarizing plate, and the polarization direction of the first circular polarizing plate are opposite to each other. It ’s an electronic device,
Cover panel and
A first circular polarizing plate arranged under the cover panel and
An OLED panel arranged under the first circular polarizing plate and
A light emitting unit arranged under the OLED panel and
A light receiving sensor arranged under the OLED panel is provided.
The light emitting unit includes an LED.
The light receiving sensor includes a light receiving element and includes a light receiving element.
The electronic device further
A second circular polarizing plate arranged above the LED,
A third circular polarizing plate arranged on the upper side of the light receiving element is provided.
The second circular polarizing plate is attached to the lower surface of the OLED panel.
The third circular polarizing plate is attached to the lower surface of the OLED panel.
The polarization direction of the second circular polarizing plate and the polarization direction of the third circular polarizing plate are the same.
An electronic device in which the polarization direction of the second circular polarizing plate, the polarization direction of the third circular polarizing plate, and the polarization direction of the first circular polarizing plate are opposite to each other.

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