JP7413657B2 - Optical equipment and information processing equipment - Google Patents

Description

The present invention relates to a light emitting device, an optical device, and an information processing device.

Patent Document 1 discloses a light source that includes a light source, a plurality of lenses arranged adjacent to each other on a predetermined plane, a diffuser plate that diffuses light emitted from the light source, and a light diffuser that diffuses light that is diffused by the diffuser plate when the subject is photographed. An imaging device is described in which the imaging device includes an imaging element that receives reflected light, and a plurality of lenses are arranged such that the period of interference fringes in the diffused light is three pixels or less.

Japanese Patent Application Publication No. 2018-54769

Incidentally, a configuration is known in which the three-dimensional shape of an object to be measured is measured by diffusing and irradiating the object to be measured with light emitted from a light source via a light diffusing member or the like.
In this case, from the viewpoint of energy saving, etc., a light source for proximity detection that detects whether the object to be measured is within a predetermined distance, and a light diffusion member that emits light with a higher light output than the light source for proximity detection. A configuration including a light source for three-dimensional measurement that diffusely irradiates the object to be measured via a light source or the like is conceivable.
Here, as a light source for proximity detection, it is desirable that the divergence angle is not too wide so that the light density does not decrease too much on the irradiated surface of the object to be measured. On the other hand, as a light source for three-dimensional measurement, a narrow divergence angle is not desired because the light is diffused by a light diffusing member, etc., but rather a high light output is desired.

The present invention provides a configuration that includes a first light source and a second light source that has a larger light output than the first light source and is configured to be driven independently of the first light source, and is used for diffused irradiation. Compared to a configuration in which light is irradiated from the first light source at the same divergence angle as the second light source, a decrease in the light density of the light emitted from the first light source on the irradiation surface is suppressed. Provides light emitting devices, etc.

The invention according to claim 1 includes a first light source that oscillates in a single transverse mode, a light output larger than the first light source, and configured to be driven independently of the first light source. a second light source that oscillates in multiple transverse modes; a first reflected light emitted from the first light source and reflected by the object to be measured; and a first reflected light emitted from the second light source and reflected by the object to be measured. a light receiving section that receives the second reflected light , the second light source emits light via a light diffusing member provided on the emission path of the second light source, and The optical device emits light from the second light source when the reflected light indicates that the object to be measured is present within a predetermined distance.
The invention according to claim 2 includes a first light source that oscillates in a single transverse mode, a light output larger than the first light source, and configured to be driven independently of the first light source. a second light source that oscillates in multiple transverse modes; a first reflected light emitted from the first light source and reflected by the object to be measured; and a first reflected light emitted from the second light source and reflected by the object to be measured. A light receiving unit that receives second reflected light, and the first reflected light to confirm whether or not the object to be measured is within a predetermined distance, and measure the shape using the second reflected light. the second light source is an optical device that emits light via a light diffusing member provided on an emission path of the second light source .
In the invention according to claim 3, the first light source includes at least one first vertical cavity surface emitting laser element, and the second light source includes a plurality of second vertical cavity surface emitting laser elements. including a laser element, such that the optical output emitted from one first vertical cavity surface emitting laser element is smaller than the optical output emitted from one second vertical cavity surface emitting laser element. 3. The optical device according to claim 1, wherein the optical device is driven by:
In the invention according to claim 4, the first light source includes at least one first vertical cavity surface emitting laser element, and the second light source includes a plurality of second vertical cavity surface emitting laser elements. 3. The laser device comprises a laser element, and is driven with an optical output such that the power conversion efficiency of the first vertical cavity surface emitting laser element is lower than the power conversion efficiency of the second vertical cavity surface emitting laser element. This is the optical device described in .
In the invention according to claim 5, the first vertical cavity surface emitting laser element is driven such that the optical output of one first vertical cavity surface emitting laser element is in the range of 1 mW to 4 mW. 5. The optical device according to claim 3 or 4.
In the invention according to claim 6, the second vertical cavity surface emitting laser device is driven such that the optical output of one second vertical cavity surface emitting laser device is in the range of 4 mW to 8 mW. 6. The optical device according to any one of claims 3 to 5.
The invention according to claim 7 is characterized in that the first vertical cavity surface emitting laser element has a long cavity structure having a cavity length of 5λ to 20λ, where λ is the oscillation wavelength. 6. The optical device according to any one of 6.
In the invention according to claim 8, the light receiving unit may transmit a signal corresponding to a time from when light is emitted from the first light source until it is received by the light receiving unit, and when light is emitted from the second light source. 3. The optical device according to claim 1, wherein the optical device outputs a signal corresponding to the time from when the light is emitted to when the light is received by the light receiving section.
The invention according to claim 9 includes the optical device according to any one of claims 1 to 8, and second reflected light emitted from a second light source included in the optical device and reflected by a measured object. An information processing apparatus includes a shape identifying section that identifies a three-dimensional shape of the object to be measured based on the following.
The invention according to claim 10 is the information processing apparatus according to claim 9, further comprising: an authentication processing section that performs authentication processing regarding use of the own device based on the identification result of the shape identification section.

According to the invention described in claims 1 and 2 , when the object to be measured does not exist within a predetermined distance, no light is emitted from the second light source.
According to the invention described in claim 3 , compared with the case where the optical output of the first vertical cavity surface emitting laser device is made to match the optical output of the second vertical cavity surface emitting laser device, Decrease in optical density on the irradiation surface of the light emitted from the cavity surface emitting laser element is suppressed.
According to the invention described in claim 4 , the power conversion efficiency of the first vertical cavity surface emitting laser device is compared with the power conversion efficiency of the second vertical cavity surface emitting laser device, and A decrease in optical density at the irradiation surface of the light emitted from the vertical cavity surface emitting laser element is suppressed.
According to the invention set forth in claim 5 , light with a narrower spread angle is irradiated than when driven in a region exceeding 4 mW.
According to the sixth aspect of the invention, the power conversion efficiency of the second vertical cavity surface emitting laser element is improved compared to the case where the second vertical cavity surface emitting laser element is driven in a region of less than 4 mW.
According to the seventh aspect of the invention, the divergence angle is narrower than in the case of a normal single-mode vertical cavity surface emitting laser element whose cavity length matches λ.
According to the invention set forth in claim 8 , an optical device capable of performing both proximity detection and three-dimensional measurement is provided.
According to the ninth aspect of the invention, an information processing device capable of measuring a three-dimensional shape is provided.
According to the tenth aspect of the invention, there is provided an information processing device equipped with authentication processing based on three-dimensional shape.

1 is a diagram illustrating an example of an information processing device to which this embodiment is applied. FIG. 2 is a block diagram illustrating the configuration of an information processing device. 1 is an example of a plan view and a cross-sectional view of an optical device. (a) is a plan view, and (b) is a sectional view taken along line IIIB-IIIB in (a). It is a figure explaining the structure of the light source for proximity detection, and the light source for 3D shape measurement. It is a figure explaining the cross-sectional structure of one VCSEL in a light source for proximity detection. It is a figure explaining the cross-sectional structure of one VCSEL in a light source for 3D shape measurement. FIG. 2 is a diagram illustrating the relationship between optical output and power conversion efficiency of a general VCSEL. FIG. 3 is a diagram illustrating an example of the configuration of a diffuser plate. (a) is a plan view, and (b) is a sectional view taken along line VIIIB-VIIIB in (a). It is a figure which shows the modification of a diffuser plate. (a) is a first modification of the diffusion plate, and (b) is a second modification of the diffusion plate. It is a figure explaining a 3D sensor. 3 is a flowchart for performing authentication processing regarding use of an information processing device. It is a figure explaining low side drive. It is a figure explaining the arrangement of the light source for proximity detection, the light source for 3D shape measurement, and the light receiving element for light intensity monitoring in a light emitting device. (a) is the arrangement described as this embodiment, (b) is the first modification of the arrangement, (c) is the second modification of the arrangement, and (d) is the arrangement This is a third modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
An information processing device identifies whether or not a user who has accessed the information processing device is authorized to access the information processing device, and only when the user is authenticated as a user who is authorized to access the information processing device, the information processing device is recognized as its own device. In many cases, the use of information processing equipment is permitted. Until now, methods have been used to authenticate users using passwords, fingerprints, iris, and the like. Recently, there has been a demand for authentication methods with even higher security. As this method, authentication is performed using a three-dimensional image, such as the shape of the user's face.
Here, the information processing apparatus will be described as an example of a portable information processing terminal, and the user will be authenticated by recognizing the shape of a face captured as a three-dimensional image. Note that the information processing device may be applied to information processing devices such as a personal computer (PC) other than a portable information processing terminal.
Further, the configuration, function, method, etc. described in this embodiment can be applied not only to recognizing the shape of a face but also to recognizing the three-dimensional shape of an object. That is, the present invention may be applied to recognition of the shape of an object other than a face as the object to be measured. Further, the distance to the object to be measured does not matter.

[Information processing device 1]
FIG. 1 is a diagram showing an example of an information processing device 1 to which this embodiment is applied. As described above, the information processing device 1 is, for example, a portable information processing terminal.
The information processing device 1 includes a user interface section (hereinafter referred to as a UI section) 2 and an optical device 3 that acquires a three-dimensional image. The UI unit 2 is configured by integrating, for example, a display device that displays information to the user and an input device that inputs instructions for information processing through user operations. The display device is, for example, a liquid crystal display or an organic EL display, and the input device is, for example, a touch panel.

The optical device 3 includes a light emitting device 4 and a three-dimensional sensor (hereinafter referred to as a 3D sensor) 6. The light emitting device 4 emits light toward the object to be measured, in the example described here, the face, in order to obtain a three-dimensional image. The 3D sensor 6 acquires the light emitted by the light emitting device 4 that is reflected by the face and returned. Here, it is assumed that a three-dimensional image of the face is obtained based on the so-called TOF (Time of Flight) method, which uses the flight time of light. In the following, even when the face is the object to be measured, it will be referred to as the object to be measured.

Note that the information processing device 1 is configured as a computer including a CPU, ROM, RAM, and the like. Note that the ROM includes a nonvolatile rewritable memory, such as a flash memory. The programs and constants stored in the ROM are expanded into the RAM and executed by the CPU, thereby operating the information processing device 1 and performing various information processing.

FIG. 2 is a block diagram illustrating the configuration of the information processing device 1. As shown in FIG.
The information processing device 1 includes the optical device 3 described above, an optical device control section 8, and a system control section 9. The optical device 3 includes the light emitting device 4 and the 3D sensor 6 as described above. The optical device control section 8 controls the optical device 3. The optical device control section 8 includes a shape identification section 81 . The system control unit 9 controls the entire information processing device 1 as a system. The system control unit 9 includes an authentication processing unit 91. The system control unit 9 is connected to a UI unit 2, a speaker 92, a two-dimensional (2D) camera 93, and the like. Note that the 3D sensor 6 is an example of a light receiving section.
Below, they will be explained in order.

The optical device 3 includes the light emitting device 4 and the 3D sensor 6 as described above. The light emitting device 4 includes a light source 10 for proximity detection, a light source 20 for 3D shape measurement, a diffusion plate 30, a light receiving element (denoted as PD in FIG. 2) 40 for monitoring light amount, and a first drive unit 50A. and a second drive section 50B. Note that the proximity detection light source 10 is an example of a first light source, the 3D shape measurement light source 20 is an example of a second light source, and the diffusion plate 30 is an example of a light diffusion member.

The first drive unit 50A in the light emitting device 4 drives the proximity detection light source 10, and the second drive unit 50B drives the 3D shape measurement light source 20. For example, the proximity detection light source 10 and the 3D shape measurement light source 20 are driven to emit pulsed light (hereinafter referred to as emitted light pulse) of several tens of MHz to several hundred MHz.
As described later, the optical device 3 uses the 3D sensor 6 to detect the reflected light from the object to be measured with respect to the light irradiated toward the object from the light source 10 for proximity detection and the light source 20 for 3D shape measurement. It is configured to receive light.

The 3D sensor 6 includes a plurality of light receiving areas 61 (see FIG. 10 described later). The 3D sensor 6 receives a signal corresponding to the time from when the light emitted from the light source 10 for proximity detection is emitted until it is reflected by the object to be measured and received by the 3D sensor 6, and a signal emitted from the light source 20 for 3D shape measurement. A signal corresponding to the time from when the light is emitted until it is reflected by the object to be measured and received by the 3D sensor 6 is output. Note that the 3D sensor 6 may include a lens for condensing light.
The light emitted from the light source 10 for proximity detection and reflected from the object to be measured is an example of the first reflected light, and the light emitted from the light source 20 for 3D shape measurement and reflected from the object to be measured is an example of the second reflected light. This is an example of reflected light.

The shape identification unit 81 of the optical device control unit 8 acquires a digital value obtained for each light receiving area 61 from the 3D sensor 6, calculates the distance to the object to be measured for each light receiving area 61, and determines the 3D value of the object to be measured. Identify the shape.
The authentication processing unit 91 of the system control unit 9 determines whether the information processing device 1 is used when the 3D shape of the object to be measured, which is the identification result identified by the shape identification unit 81, is a 3D shape stored in advance in a ROM or the like. Perform authentication processing. Note that the authentication process regarding use of the information processing device 1 is, for example, a process of determining whether or not to permit use of the information processing device 1 itself. For example, if the 3D shape of the face that is the object to be measured matches the face shape stored in a storage member such as a ROM, the information processing device 1 that is the own device including various applications provided by the information processing device 1 is permitted to be used.
The shape identifying section 81 and the authentication processing section 91 described above are configured by, for example, a program. Alternatively, it may be configured with an integrated circuit such as ASIC or FPGA. Furthermore, it may be composed of software such as a program and an integrated circuit.

Although the optical device 3, the optical device control section 8, and the system control section 9 are shown separately in FIG. 2, the system control section 9 may include the optical device control section 8. Further, the optical device control section 8 may be included in the optical device 3. Furthermore, the optical device 3, the optical device control section 8, and the system control section 9 may be integrally configured.

(Overall configuration of optical device 3)
Next, the optical device 3 will be explained in detail.
FIG. 3 is an example of a plan view and a cross-sectional view of the optical device 3. FIG. 3(a) is a plan view, and FIG. 3(b) is a cross-sectional view taken along line IIIB-IIIB in FIG. 3(a). Here, in FIG. 3A, the lateral direction of the page is the x direction, and the upward direction of the page is the y direction. The direction perpendicular to the x direction and the y direction in a counterclockwise direction is defined as the z direction.

As shown in FIG. 3A, the optical device 3 includes a light emitting device 4 and a 3D sensor 6 arranged on the circuit board 7 in the x direction. The circuit board 7 uses a plate-shaped member made of an insulating material as a base material, and is provided with a conductive pattern made of a conductive material. The insulating material is made of, for example, ceramic or epoxy resin. A conductor pattern made of a conductive material is provided on the circuit board 7. Note that the conductive material is, for example, a metal such as copper (Cu) or silver (Ag), or a conductive paste containing these metals. The circuit board 7 may be a single-layer board with a conductor pattern provided on its surface, or may be a multi-layer board with a plurality of conductor patterns. Further, the light emitting device 4 and the 3D sensor 6 may be placed on separate circuit boards.

Although the light emitting device 4 is an example, the light receiving element 40 for light amount monitoring, the light source 20 for 3D shape measurement, the light source 10 for proximity detection, and the first drive unit 50A are arranged in the +x direction on the circuit board 7. and second drive section 50B are arranged in this order.

The proximity detection light source 10 and the 3D shape measurement light source 20 each have a rectangular shape when viewed from above, that is, a planar shape, and emit light in the same direction (the z direction in FIG. 3(b)). Note that the planar shapes of the proximity detection light source 10 and the 3D shape measurement light source 20 do not have to be quadrangular. Further, the proximity detection light source 10 and the 3D shape measurement light source 20 may be mounted directly on the circuit board 7, or may be mounted on the circuit board 7 with a heat dissipation base material such as aluminum oxide or aluminum nitride interposed therebetween. It may be mounted on top. In the following description, it will be assumed that the proximity detection light source 10 and the 3D shape measurement light source 20 are mounted directly on the circuit board 7. Here, "planar view" means viewing from the z direction in FIG. 3(a). The same applies below.

A first drive unit 50A that drives the proximity detection light source 10 and a second drive unit 50B that drives the 3D shape measurement light source 20 are arranged side by side in the y direction on the circuit board 7. The rated output of the first drive section 50A is set smaller than the rated output of the second drive section 50B. Therefore, the first drive section 50A is also smaller in external size than the second drive section 50B. Since the second drive unit 50B needs to drive the 3D shape measurement light source 20 with a large current, it is arranged preferentially over the first drive unit 50A so that the distance to the 3D shape measurement light source 20 is shortened. ing. That is, the second drive unit 50B is arranged so that the wiring connected to the 3D shape measurement light source 20 has a wide pattern width. On the other hand, the first drive section 50A is disposed at a position laterally shifted from the second drive section 50B, that is, on the +y direction side of the second drive section 50B.

The proximity detection light source 10 is arranged on the circuit board 7 between the 3D shape measurement light source 20 and the second drive unit 50B. Further, the light receiving element 40 for light amount monitoring is located at a position on the circuit board 7 close to the light source 20 for 3D shape measurement, that is, at a position where the second drive unit 50B is arranged with respect to the light source 20 for 3D shape measurement. is placed on the opposite side. In this way, by arranging the proximity detection light source 10, the 3D shape measurement light source 20, and the light receiving element 40 for light amount monitoring close to each other, it becomes easier to cover these components with the common diffuser plate 30. On the other hand, when the proximity detection light source 10 and the 3D shape measurement light source 20 are placed apart from each other, if they are covered by a common diffuser plate 30, a large diffuser plate 30 will be required.

As shown in FIG. 3A, the diffusion plate 30 has a rectangular planar shape, for example. Note that the planar shape of the diffusion plate 30 does not have to be rectangular. As shown in FIG. 3B, the diffusion plate 30 is supported by a spacer 33 on the light emission direction side of the proximity detection light source 10 and the 3D shape measurement light source 20, and is It is provided at a predetermined distance from the measurement light source 20. The diffusion plate 30 is provided so as to cover the proximity detection light source 10, the 3D shape measurement light source 20, and the light receiving element 40 for light amount monitoring. Note that the spacer 33 is provided so as to surround the proximity detection light source 10, the 3D shape measurement light source 20, and the light receiving element 40 for light amount monitoring. If the spacer 33 is made of a member that absorbs the light emitted by the proximity detection light source 10 and the 3D shape measurement light source 20, the proximity detection light source 10 and the 3D shape measurement light source 20 will be emitted through the spacer 33. This prevents the light from being emitted to the outside. Further, by sealing the proximity detection light source 10, the 3D shape measurement light source 20, etc. with the diffusion plate 30 and the spacer 33, dustproofing, moistureproofing, etc. can be achieved. In this embodiment, by arranging the proximity detection light source 10, the 3D shape measurement light source 20, and the light receiving element 40 for light amount monitoring close to each other, it becomes easier to surround them with a small-sized spacer 33. On the other hand, when the proximity detection light source 10 and the 3D shape measurement light source 20 are arranged apart from each other, if they are surrounded by a common spacer 33, a large spacer 33 is required. Alternatively, a configuration may be considered in which two small-sized spacers 33 are prepared to separately surround the proximity detection light source 10 and the 3D shape measurement light source 20, but the number of components would double. Furthermore, no spacer 33 is provided between the proximity detection light source 10 and the 3D shape measurement light source 20. Therefore, compared to a configuration in which the spacer 33 is provided therebetween, the light emitting device 4 is smaller in size.

The light receiving element 40 for monitoring the amount of light is, for example, a photodiode (PD) made of silicon or the like and outputting an electric signal according to the amount of received light.
The light receiving element 40 for monitoring the amount of light receives the light emitted from the light source 20 for 3D shape measurement and reflected by the back surface of the diffuser plate 30, that is, the surface on the -z direction side. Note that the light receiving element 40 for monitoring the amount of light may receive light emitted from the light source 10 for proximity detection and reflected on the back surface of the diffuser plate 30.

The 3D shape measurement light source 20 maintains a predetermined light output by the second drive unit 50B via the optical device control unit 8 based on the amount of light received by the light receiving element 40 for monitoring the amount of light. controlled as follows.

In addition, if the amount of light received by the light receiving element 40 for monitoring the amount of light decreases extremely, the diffuser plate 30 may come off or be damaged, and the light emitted from the light source 20 for 3D shape measurement may be directly irradiated to the outside. There is a possibility that there may be. In such a case, the optical output of the 3D shape measurement light source 20 is suppressed by the second drive unit 50B via the optical device control unit 8. For example, the irradiation of light from the 3D shape measurement light source 20 is stopped.

In the light emitting device 4, the first drive unit 50A drives the proximity detection light source 10 to emit light for detecting the proximity of the object to be measured. The second drive unit 50B drives the 3D shape measurement light source 20 to emit light for measuring the 3D shape of the object. The light receiving element 40 for monitoring the light amount receives the light reflected by the diffuser plate 30 out of the light emitted by the light source 20 for 3D shape measurement, and monitors the light output of the light source 20 for 3D shape measurement. Then, based on the light output of the 3D shape measurement light source 20 monitored by the light receiving element 40 for monitoring the amount of light, the light output of the 3D shape measurement light source 20 is controlled via the second drive unit 50B. Note that the light receiving element 40 for monitoring the amount of light may monitor the light output of the light source 10 for proximity detection, similarly to the light source 20 for 3D shape measurement.

(Configuration of proximity detection light source 10 and 3D shape measurement light source 20)
FIG. 4 is a diagram illustrating the configurations of the proximity detection light source 10 and the 3D shape measurement light source 20. The proximity detection light source 10 includes a vertical cavity surface emitting laser element VCSEL (Vertical Cavity Surface Emitting Laser)-A. On the other hand, the 3D shape measurement light source 20 is configured to include a vertical cavity surface emitting laser element VCSEL-B. Hereinafter, the vertical cavity surface emitting laser element VCSEL-A will be referred to as VCSEL-A, and the vertical cavity surface emitting laser element VCSEL-B will be referred to as VCSEL-B. Note that when VCSEL-A and VCSEL-B are not distinguished, they are written as VCSEL. VCSEL-A is an example of a first vertical cavity surface emitting laser device, and VCSEL-B is an example of a second vertical cavity surface emitting laser device.

VCSEL is a light-emitting element that has an active region serving as a light-emitting region between a lower multilayer film reflector and an upper multilayer film reflector stacked on a substrate, and emits laser light in a direction perpendicular to the substrate. It is easy to create a dimensional array. Here, it is assumed that the proximity detection light source 10 includes one or more VCSEL-A, and the 3D shape measurement light source 20 includes a plurality of VCSEL-B.

The VCSEL-A of the proximity detection light source 10 emits light for detecting whether the object to be measured is close to the information processing device 1. On the other hand, the VCSEL-B of the 3D shape measurement light source 20 emits light for measuring the 3D shape of the object to be measured. In the case of face recognition as an example, the measurement distance is about 10 cm to about 1 m. The range in which the 3D shape of the object to be measured is measured (hereinafter referred to as a measurement range or irradiation range, and this range is referred to as an irradiation surface) is about 1 m square.

In this case, the number of VCSEL-A of the light source 10 for proximity detection is 1 to 50, and the number of VCSEL-B of the light source 20 for 3D shape measurement is 100 to 1000. That is, the number of VCSEL-B of the 3D shape measurement light source 20 is larger than the number of VCSEL-A of the proximity detection light source 10. As will be described later, the plurality of VCSEL-A of the proximity detection light source 10 are connected in parallel to each other and driven in parallel. Further, the plurality of VCSEL-Bs of the 3D shape measurement light source 20 are similarly connected to each other in parallel and driven in parallel. Note that the number of VCSELs described above is just an example, and may be set according to the measurement distance and measurement range. The proximity detection light source 10 shown in FIG. 4 includes, for example, four VCSEL-A.

The proximity detection light source 10 does not need to irradiate the entire surface of the measurement range with light; it is sufficient to detect whether or not the object to be measured has approached the measurement range. Therefore, the light source 10 for proximity detection only needs to irradiate light onto a part of the measurement range. Therefore, the number of VCSEL-A in the proximity detection light source 10 may be small. When there is a request to use the information processing device 1, the proximity detection light source 10 illuminates the measurement range at a predetermined period in order to detect whether the object to be measured has approached the information processing device 1. irradiate. Therefore, the proximity detection light source 10 is required to have low power consumption.

On the other hand, the 3D shape measurement light source 20 irradiates the entire surface of the measurement range with light when it is detected that the object to be measured approaches the measurement range. Then, the 3D shape is identified from the reflected light that the 3D sensor 6 receives from the measurement range. Therefore, the VCSEL-B of the 3D shape measurement light source 20 is required to have a large amount of emitted light. A large number of VCSEL-Bs are included in order to uniformly illuminate the entire measurement range. Note that since the 3D shape measurement light source 20 emits light only when measuring a 3D shape, it is acceptable even if the power consumption is high.

(Structure of VCSEL-A of proximity detection light source 10)
Next, the structure of the VCSEL-A of the proximity detection light source 10 will be explained.
The proximity detection light source 10 emits light in order to detect whether or not the object to be measured is in proximity. Therefore, it is preferable that the VCSEL-A of the proximity detection light source 10 has a low output and has a light density at a predetermined distance at a predetermined value. In other words, the light density should be such that the reflected light from the object to be measured is reliably detected by the 3D sensor 6 with low power consumption. Therefore, the VCSEL-A is required to have a small divergence angle of emitted light and a small decrease in optical density with respect to distance.
Note that light density refers to irradiance.

Here, as an example, a single mode VCSEL that oscillates in a single transverse mode, that is, a single mode, is used as the VCSEL-A of the proximity detection light source 10. A single-mode VCSEL has a smaller spread angle of emitted light than a multi-mode VCSEL that oscillates in multiple transverse modes, that is, multiple modes. Therefore, even if the optical output is the same, a single-mode VCSEL has a higher optical density on the irradiation surface than a multi-mode VCSEL. Note that the spread angle of the emitted light refers to the full width at half maximum (FWHM) of the light emitted from the VCSEL (see θ1 and θ2 in FIG. 8(b)). Note that the single transverse mode refers to a mode in which the intensity profile of the emitted light using the divergence angle as a parameter is unimodal, that is, the intensity profile has one intensity peak. For example, a plurality of transverse modes may be included within a range where unimodal property is maintained.

A VCSEL with a long resonator structure may be used as a single mode VCSEL.
A VCSEL with a long resonator structure has a spacer of several λ to several tens of λ between the active region in a VCSEL with a general λ resonator structure in which the resonator length is equal to the oscillation wavelength λ and one multilayer reflective mirror. Introducing a layer to increase the cavity length increases the loss of higher-order transverse modes, which enables single-mode oscillation with an oxidized aperture diameter larger than that of a typical λ-resonator VCSEL. enable. A VCSEL with a typical λ resonator structure has a large longitudinal mode spacing (sometimes referred to as a free spectral range), so stable operation can be obtained in a single longitudinal mode. On the other hand, in the case of a VCSEL with a long resonator structure, the longer the resonator length, the narrower the longitudinal mode spacing, and the presence of multiple longitudinal modes of standing waves within the resonator. Switching between longitudinal modes becomes more likely to occur. Therefore, in a VCSEL with a long resonator structure, it is required to suppress switching between longitudinal modes.
In addition, in a VCSEL having a long resonator structure, it is easier to set the divergence angle narrower than in a single mode VCSEL having a general λ resonator structure.

FIG. 5 is a diagram illustrating the cross-sectional structure of one VCSEL-A in the proximity detection light source 10. VCSEL-A is a VCSEL with a long resonator structure.
The VCSEL-A is formed on an n-type GaAs substrate 100, an n-type distributed Bragg reflector (DBR) 102 in which AlGaAs layers with different Al compositions are alternately stacked, and a lower DBR 102. In addition, a resonator extension region 104 for extending the resonator length, an n-type carrier block layer 105 formed on the resonator extension region 104, and an upper and lower spacer layer formed on the carrier block layer 105 sandwiched between The active region 106 includes a quantum well layer, and a p-type upper DBR 108 in which AlGaAs layers having different Al compositions formed on the active region 106 are alternately stacked.

The n-type lower DBR 102 is a multilayer laminate consisting of a pair of Al _0.9 Ga _0.1 As layers and GaAs layers, and the thickness of each layer is λ/4n _r (where λ is the oscillation wavelength and n _r is (refractive index of the medium), and these are alternately stacked at 40 periods. The carrier concentration after doping silicon, which is an n-type impurity, is, for example, 3×10 ¹⁸ cm ⁻³ .

The cavity extension region 104 is a monolithic layer formed by a series of epitaxial growths. Therefore, the resonator extension region 104 is made of AlGaAs, GaAs, or AlAs whose lattice constant matches or matches the GaAs substrate. Here, in order to emit laser light in the 940 nm band, the resonator extension region 104 is made of AlGaAs, which does not cause light absorption. The film thickness of the resonator extension region 104 is set to about 2 μm to 5 μm, and 5λ to 20λ of the oscillation wavelength λ. For this reason, the moving distance of the carrier becomes long. Therefore, the resonator extension region 104 is desirably of n-type having high carrier mobility, and is therefore inserted between the n-type lower DBR 102 and the active region 106. Such a resonator extension region 104 is sometimes referred to as a cavity extension region or cavity space.

Preferably, a carrier block layer 105 with a large bandgap made of Al _0.9 Ga _0.1 As, for example, is formed between the resonator extension region 104 and the active region 106 . Insertion of the carrier block layer 105 prevents carrier leakage from the active region 106 and improves luminous efficiency. As will be described later, a layer 120 that provides an optical loss that somewhat attenuates the oscillation intensity of the laser beam is inserted into the resonator extension region 104, so the carrier block layer 105 has a role of compensating for such loss. Responsible for For example, the film thickness of the carrier block layer 105 is λ/4mn _r (where λ is the oscillation wavelength, m is an integer, and n _r is the refractive index of the medium).

The active region 106 is configured by laminating a lower spacer layer, a quantum well active layer, and an upper spacer layer. For example, the lower spacer layer is an undoped Al _0.6 Ga _0.4 As layer, the quantum well active layer is an undoped InGaAs quantum well layer and an undoped GaAs barrier layer, and the upper spacer layer is an undoped Al 0.6 Ga 0.4 As layer. It is an Al _0.6 Ga _0.4 As layer.

The p-type upper DBR 108 is a laminate of a p-type Al _0.9 Ga _0.1 As layer and a GaAs layer, each layer having a thickness of λ/4n _r , and these layers are alternately stacked for 29 periods. be. The carrier concentration after doping with carbon, which is a p-type impurity, is, for example, 3×10 ¹⁸ cm ⁻³ . Preferably, a contact layer made of p-type GaAs is formed in the uppermost layer of the upper DBR 108, and a current confinement layer 110 made of p-type AlAs is formed in the lowermost layer of the upper DBR 108 or inside it.

By etching the stacked semiconductor layers from the upper DBR 108 to the lower DBR 102, a cylindrical mesa M1 is formed on the substrate 100, and the current confinement layer 110 is exposed on the side surface of the mesa M1. In the current confinement layer 110, an oxidized region 110A selectively oxidized from the side surface of the mesa M1 and a conductive region 110B surrounded by the oxidized region 110A are formed. Conductive region 110B is an oxidized aperture. In the oxidation process, the oxidation rate of the AlAs layer is faster than that of the AlGaAs layer, and the oxidized region 110A is oxidized at a substantially constant rate from the side surface of the mesa M1 toward the inside, so that the planar shape of the conductive region 110B is parallel to the substrate. has a shape that reflects the outer shape of mesa M1, that is, a circular shape, and its center almost coincides with the axial direction of mesa M1 shown by the dashed line. In VCSEL-A with a long resonator structure, the diameter of the conductive region 110B for obtaining a single transverse mode can be made larger than in a VCSEL with a normal λ resonator structure. For example, the diameter of the conductive region 110B can be set to 7 μm. It can be increased to about 8 μm.

A metal annular p-side electrode 112 made of a stack of Ti/Au or the like is formed on the uppermost layer of the mesa M1. The p-side electrode 112 makes ohmic contact with the contact layer of the upper DBR 108. The inside of the annular p-side electrode 112 serves as a light exit aperture 112A through which laser light is emitted to the outside. In other words, the direction of the central axis of mesa M1 becomes the optical axis. Furthermore, a cathode electrode 114 is formed on the back surface of the substrate 100 as an n-side electrode. Note that the surface of the upper DBR 108 including the light exit aperture 112A is the exit surface.

Then, an insulating layer 116 is provided so as to cover the surface of the mesa M1, except for a portion where the p-side electrode 112 and an anode electrode 118, which will be described later, are connected and the light exit aperture 112A. The anode electrode 118 is provided in ohmic contact with the p-side electrode 112 except for the light exit aperture 112A. Note that the anode electrode 118 is provided except for the light exit aperture 112A of each of the plurality of VCSEL-A. In other words, the plurality of VCSEL-A's of the proximity detection light source 10 are connected in parallel with each other, with their respective p-side electrodes 112 connected at the anode electrode 118.

In a VCSEL with a long resonator structure, a plurality of longitudinal modes may exist within a reflection band defined by the resonator length, so it is necessary to suppress switching or popping between the longitudinal modes. Here, the necessary longitudinal mode oscillation wavelength band is set to 940 nm, and in order to suppress switching to other longitudinal mode oscillation wavelength bands, unnecessary longitudinal mode standing waves are set in the resonator extension region 104. A layer 120 providing optical loss is provided. In other words, the layer 120 providing optical loss is introduced at the node of the standing wave of the required longitudinal mode. The layer 120 providing optical loss is made of a semiconductor material having the same Al composition as the semiconductor layer constituting the resonator extension region 104, and is made of, for example, Al _0.3 Ga _0.7 As. The layer 120 providing optical loss preferably has a higher impurity doping concentration than the semiconductor layer constituting the resonator extension region 104, for example, the impurity concentration of AlGaAs constituting the resonator extension region 104 is 1×10 ¹⁷ cm ^-3 , the layer 120 providing optical loss has an impurity concentration of 1×10 ¹⁸ cm ^-3 , and is configured so that the impurity concentration is about one order of magnitude higher than that of other semiconductor layers. . As the impurity concentration increases, light absorption by carriers increases, resulting in loss. The thickness of the layer 120 providing optical loss is selected so that the loss to the necessary longitudinal mode does not become large, and is preferably about the same thickness (10 nm) as the current confinement layer 110 located at the node of the standing wave. ~30 nm).

The layer 120 providing optical loss is inserted so as to be located at a node for the required longitudinal mode standing wave. Since the standing wave nodes have low intensity, the effect of the loss on the necessary longitudinal mode by the layer 120 providing optical loss is small. On the other hand, for unnecessary longitudinal mode standing waves, the layer 120 that provides optical loss is located at the antinode other than the node. Since the antinodes of the standing wave have a higher intensity than the nodes, the loss that the layer 120 that provides optical loss gives to unnecessary longitudinal modes becomes large. In this way, by increasing the loss to unnecessary longitudinal modes while reducing the loss to necessary longitudinal modes, unnecessary longitudinal modes are selectively prevented from resonating, and longitudinal mode hopping is suppressed.

The layer 120 providing optical loss does not necessarily need to be provided at each node of the required longitudinal mode standing wave in the resonator extension region 104, and may be a single layer. In this case, the intensity of the standing wave increases as it approaches the active region 106, so the layer 120 that provides optical loss may be formed at a node position close to the active region 106. Furthermore, if switching or popping between longitudinal modes is allowed, the layer 120 that provides optical loss may not be provided.

(VCSEL-B of 3D shape measurement light source 20)
Next, VCSEL-B of the 3D shape measurement light source 20 will be explained.
Here, the 3D shape measurement light source 20 irradiates light to specify the 3D shape of the object to be measured. Therefore, a predetermined measurement range is irradiated with a predetermined light density. Therefore, here, it is preferable that the VCSEL-B of the 3D shape measurement light source 20 be configured with a multi-mode VCSEL, which is easier to increase the output than a single-mode VCSEL.

FIG. 6 is a diagram illustrating the cross-sectional structure of one VCSEL-B in the 3D shape measurement light source 20. This VCSEL-B is the general λ resonator structure VCSEL described above. That is, VCSEL-B does not include the resonator extension region 104 in VCSEL-A described above.

VCSEL-B includes an n-type lower DBR 202 in which AlGaAs layers with different Al compositions are alternately stacked on a substrate 200 made of n-type GaAs, and an upper spacer layer and a lower spacer layer formed on the lower DBR 202. An active region 206 including a quantum well layer sandwiched between the active region 206 and a p-type upper DBR 208 in which AlGaAs layers having different Al compositions formed on the active region 206 are alternately stacked. Note that a p-type AlAs current confinement layer 210 is formed at the bottom layer of the upper DBR 208 or inside it.

The lower DBR 202, the active region 206, the upper DBR 208, and the current confinement layer 210 are the same as the lower DBR 102, the active region 106, the upper DBR 108, and the current confinement layer 110 of the VCSEL-A described above, so a description thereof will be omitted.

By etching the stacked semiconductor layers from the upper DBR 208 to the lower DBR 202, a cylindrical mesa M2 is formed on the substrate 200, and the current confinement layer 210 is exposed on the side surface of the mesa M2. In the current confinement layer 210, an oxidized region 210A selectively oxidized from the side surface of the mesa M2 and a conductive region 210B surrounded by the oxidized region 210A are formed. Conductive region 210B is an oxidized aperture. The planar shape of the conductive region 210B parallel to the substrate is a shape that reflects the outer shape of the mesa M2, that is, a circular shape, and its center almost coincides with the axial direction of the mesa M2 shown by the dashed line.

An annular p-side electrode 212 made of metal such as a stack of Ti/Au is formed on the uppermost layer of the mesa M2, and the p-side electrode 212 is ohmically connected to the contact layer of the upper DBR 208. A circular light exit aperture 212A whose center coincides with the axial direction of the mesa M2 is formed in the p-side electrode 212, and laser light is emitted to the outside from the light exit aperture 212A. In other words, the axial direction of mesa M2 becomes the optical axis. Furthermore, a cathode electrode 214 as an n-side electrode is formed on the back surface of the substrate 200. Note that the surface of the upper DBR 208 including the light exit port 212A is the exit surface.

Then, an insulating layer 216 is provided so as to cover the surface of the mesa M2, except for a portion where the p-side electrode 212 and an anode electrode 218, which will be described later, are connected and the light exit port 212A. The anode electrode 218 is provided in ohmic contact with the p-side electrode 212 except for the light exit aperture 212A. Note that the anode electrode 218 is provided except for the light exit aperture 212A of each of the plurality of VCSEL-Bs. In other words, the plurality of VCSEL-Bs constituting the 3D shape measurement light source 20 are connected in parallel with each other, with their respective p-side electrodes 212 connected at the anode electrode 218.

FIG. 7 is a diagram illustrating the relationship between optical output and power conversion efficiency of a general VCSEL.
Generally, the power conversion efficiency of a VCSEL is maximized when the optical output of one VCSEL is 4 mW to 8 mW. However, compared to the case where the light output is used in a smaller range, the divergence angle becomes larger, and the light density at the irradiation surface does not increase in proportion to the increase in the light output.
Here, it is preferable that the VCSEL-A of the proximity detection light source 10 be driven within a light output range in which the power conversion efficiency decreases. In other words, by intentionally emitting light at a lower light output than the range where the power conversion efficiency can be maximized, the light is emitted at a narrow spread angle. Note that if the light density is insufficient on the irradiation surface, the light density can be increased while maintaining a narrow divergence angle by increasing the number of VCSEL-A rather than increasing the light output per VCSEL-A. . Note that, as an example, the optical output of one VCSEL-A is set to 1 mW to 4 mW. The number of VCSEL-A in the proximity detection light source 10 is, for example, 1 to 50. Note that in the configuration shown in FIG. 4, as described above, in order to increase the light density while avoiding the range where the power conversion efficiency is maximum (4 mW to 8 mW), the proximity detection light source 10 is configured to include a plurality of VCSEL-A. It is composed of

On the other hand, the VCSEL-B of the 3D shape measurement light source 20 is preferably driven to a range of optical output in which the power conversion efficiency can be maximized. Note that, as an example, the optical output of one VCSEL-B is set to 4 mW to 8 mW. The number of VCSEL-Bs in the 3D shape measurement light source 20 is, for example, 100 to 1000.

(Configuration of diffuser plate 30)
Next, the diffusion plate 30 will be explained.
FIG. 8 is a diagram illustrating an example of the configuration of the diffusion plate 30. FIG. 8(a) is a plan view, and FIG. 8(b) is a sectional view taken along line VIIIB-VIIIB in FIG. 8(a).
As shown in FIGS. 3A and 3B, the diffusion plate 30 is provided on the side from which the light source 10 for proximity detection and the light source 20 for measuring 3D shape emit light, and the light source 10 for proximity detection and the light source 20 for 3D shape measurement emit light. The light emitted from each measurement light source 20 is diffused. The diffuser plate 30 has a function of further widening the spread angle of light incident on the diffuser plate 30.

The diffusion plate 30 includes a first region 30A and a second region 30B, as shown in FIG. 8(a). In other words, the first region 30A and the second region 30B are configured as an integrated member. The first region 30A is provided on the light emission path from the VCSEL-A of the proximity detection light source 10, and the second region 30B is provided on the light emission path from the 3D shape measurement light source 20. ing. That is, as shown in FIG. 3(a), when the light emitting device 4 is viewed from the surface (planar view), the first region 30A of the diffuser plate 30 is located at the position where the proximity detection light source 10 is arranged. The second region 30B of the diffuser plate 30 is provided to face the 3D shape measurement light source 20. When the light source 10 for proximity detection and the light source 20 for 3D shape measurement are covered by a common diffusion plate 30, if the light from the light source 10 for proximity detection is also diffused by the diffusion plate 30, proximity detection becomes difficult. Therefore, in order to use the common diffuser plate 30, the diffuser plate 30 is provided with the first region 30A and the second region 30B as described above. In this embodiment, the light source 10 for proximity detection and the light source 20 for 3D shape measurement are arranged close to each other. This is because if the distance between the light source 10 for proximity detection and the light source 20 for 3D shape measurement is too large, an unnecessarily large diffuser plate will be required when a common (integral) diffuser plate 30 is used. From the above, this embodiment employs a small-sized diffuser plate 30 in which the first region 30A and the second region 30B are integrated.

The second region 30B of the diffusion plate 30 has a larger diffusion angle than the first region 30A. For example, as shown in FIG. 8(b), the diffusion plate 30 includes a resin layer 32 on one surface of a glass base material 31, which has parallel and flat surfaces, and has projections and depressions formed thereon for diffusing light. However, the first region 30A and the second region 30B have different uneven shapes, and the diffusion angle is set to be larger in the second region 30B. Note that the diffusion angle is the spread angle of light transmitted through the diffusion plate 30.

Here, the first region 30A is not provided with any unevenness and is configured to prevent light from being diffused. In the second region 30B, the resin layer 32 is provided with irregularities, but in the first region 30A, the resin layer 32 is made flat without any irregularities, or the surface of the glass substrate 31, which is parallel and flat on both sides, is exposed. Here, the first region 30A does not need to be completely flat, and may be provided with an uneven shape as long as the diffusion angle is smaller than that of the second region 30B. Further, the first region 30A of the diffusion plate 30 may be a through hole through which light passes. If it is a through hole, light will not be diffused as in the case where the first region 30A is flat. In this way, a member having a diffusion function, that is, a light diffusion member may be provided on the emission path of the 3D shape measurement light source 20.

Then, as shown in FIG. 8(b), the VCSEL-A of the proximity detection light source 10 is placed at a position facing the first region 30A of the diffusion plate 30. On the other hand, VCSEL-B of the 3D shape measurement light source 20 is placed at a position facing the second region 30B of the diffusion plate 30. The spread angle of the emitted light from VCSEL-A is assumed to be θ1, and the spread angle of the emitted light from VCSEL-B is assumed to be θ2. Note that θ1 is smaller than θ2 (θ1<θ2).

Then, when the light emitted from the VCSEL-A is transmitted through the first region 30A where no unevenness is provided, no diffusion occurs, and the spread angle θ1 of the emitted light becomes the diffusion angle α as it is, and the light is transmitted.
On the other hand, when the light emitted from the VCSEL-B passes through the second region 30B provided with unevenness, diffusion occurs, and light with a diffusion angle β larger than the spread angle θ2 of the emitted light is transmitted from the diffusion plate 30. Emits light.
Note that the spread angles θ1 and θ2 and the diffusion angles α and β are full width at half maximum (FWHM).

As explained above, the diffusion plate 30 is configured such that the diffusion angle of the first region 30A is smaller than the diffusion angle of the second region 30B. By doing so, the light emitted from the VCSEL-B of the 3D shape measurement light source 20 is further diffused in the second region 30B and emitted to the outside. As a result, a more uniform irradiation pattern can be obtained over a wider irradiation surface compared to the case where the light emitted from the VCSEL-B is emitted to the outside without being diffused in the second region 30B. Note that the second region 30B may be configured to have a uniform diffusion angle throughout the second region 30B, or may be configured such that the diffusion angle differs depending on the position within the second region 30B. You may. Further, the second region 30B may be configured such that the optical axis of the VCSEL-B and the central axis of the diffused light coincide, and the second region 30B may be configured so that the optical axis of the VCSEL-B and the central axis of the diffused light coincide with each other. The irradiation area may be expanded by intentionally shifting the axis.

Note that the first region 30A may include an optical element that narrows the spread angle θ1 of the emitted light of the VCSEL-A of the proximity detection light source 10. Such an optical element can be obtained, for example, by forming the first region 30A into a convex lens shape. Here, narrowing the divergence angle includes not only condensing the incident light, but also converting the incident light into parallel light, and narrowing the degree of diffusion even though the incident light is diffused.

The size of the first region 30A may be determined by considering the number of VCSEL-A of the proximity detection light source 10, the spread angle θ of the emitted light, the intensity of the emitted light, and the like. As an example, when used for face authentication, when the proximity detection light source 10 is configured with 1 to 50 VCSEL-A, the first area 30A has a width and a height of 50 μm to 50 μm. The range may be 500 μm. Further, in FIG. 8A, the surface shape of the first region 30A when viewed from above is circular, but it may be square, rectangular, polygonal, or a combination of these shapes. Further, the horizontal width and vertical width of the first region 30A, that is, the size of the first region 30A, may be set based on the light output emitted from the proximity detection light source 10. For example, it may be set to a range larger than the full width at half maximum of the light emitted from the proximity detection light source 10, and a range smaller than the 0.1% intensity range. Furthermore, if it is desired to bring VCSEL-A and VCSEL-B closer together, they may be set to a range smaller than the 1% intensity region or smaller than the 5% intensity region.

The size of the diffusion plate 30 including the first region 30A and the second region 30B may be, for example, 1 mm to 10 mm in width and height, and 0.1 mm to 1 mm in thickness. Note that the diffusion plate 30 only needs to cover the proximity detection light source 10, the 3D shape measurement light source 20, and the light receiving element 40 for light amount monitoring in a plan view. Further, although an example has been shown in which the shape of the diffuser plate 30 in plan view is a square shape, other shapes such as a polygon or a circle may be used. With the size and shape described above, a light diffusing member is provided that is particularly suitable for facial recognition of portable information processing terminals and for relatively short-distance measurements up to several meters.

(Positional relationship among the diffuser plate 30, VCSEL-A of the proximity detection light source 10, and VCSEL-B of the 3D shape measurement light source 20)
The positional relationship between VCSEL-A of the light source 10 for proximity detection and VCSEL-B of the light source 20 for 3D shape measurement will be explained with reference to FIG. 8(b). Here, the arrangement interval between the VCSEL-A of the proximity detection light source 10 and the VCSEL-B of the 3D shape measurement light source 20 which are adjacent to each other is p1, the interval between the VCSEL-A of the proximity detection light source 10 is p2, and 3D The distance between VCSEL-B of the shape measurement light source 20 is assumed to be p3.

At this time, as can be seen from FIG. 8(b), if the VCSEL-B gets too close to the proximity detection light source 10, that is, if the interval p1 becomes small, the high-intensity light emitted from the VCSEL-B will pass through the diffuser plate 30. The light passes through the first region 30A and is easily emitted to the outside without being diffused or with weak diffusion. Therefore, it is preferable to provide a distance between adjacent VCSEL-A and VCSEL-B. For example, VCSEL-B of the 3D shape measurement light source 20 adjacent to the first region 30A of the diffuser plate 30 is arranged so that the range of the spread angle θ2 of the emitted light does not overlap with the first region 30A of the diffuser plate 30. It is good that it is done. By doing so, compared to the case where the range of the spread angle θ2 of the emitted light of VCSEL-B of the 3D shape measurement light source 20 overlaps with the first region 30A of the diffuser plate 30, the 3D shape measurement light source The amount of light emitted from the VCSEL-B of 20 and passing through the first region 30A of the diffuser plate 30 is reduced.

For example, the spacing p1 between the adjacent VCSEL-A of the proximity detection light source 10 and the VCSEL-B of the 3D shape measurement light source 20 is set to be larger than the spacing p3 between the VCSEL-B of the 3D shape measurement light source 20. That's good.

Further, the spread angle θ1 of the emitted light of the VCSEL-A of the light source 10 for proximity detection is set smaller than the spread angle θ2 of the emitted light of the VCSEL-B of the 3D shape measurement light source 20. However, the distance g1 is from the light output port 112A of the VCSEL-A (see FIG. 5) of the light source 10 for proximity detection to the diffuser plate 30, and the distance g1 is from the light output port 212A of the VCSEL-B of the light source 20 for 3D shape measurement to the diffuser plate 30. If the distance g2 is set to the distance g2, then if the distance g1 is made smaller than the distance g2 (g1<g2), that is, the light exit port 112A of the VCSEL-A of the light source 10 for proximity detection is set to If the light exit port 212A of B is closer to the diffuser plate 30, as shown in FIG. Even if the light is small, the light is likely to pass through the first region 30A and be irradiated onto the object to be measured.

In this way, the area of the first region 30A of the diffusion plate 30 can be easily reduced. The smaller the area of the first region 30A, the more the amount of light emitted from the VCSEL-B of the 3D shape measurement light source 20 and passing through the first region 30A is reduced. VCSEL-B can be placed closer to the proximity detection light source 10. In other words, the area (dead space) where VCSEL-B cannot be placed, which occurs between the adjacent VCSEL-A of the proximity detection light source 10 and the VCSEL-B of the 3D shape measurement light source 20, is reduced, and the diffusion plate 30 and the size of the spacer 33 becomes smaller.

Further, since the VCSEL-B of the 3D shape measurement light source 20 has a higher optical output than the VCSEL-A of the proximity detection light source 10, the temperature tends to rise. Therefore, if the interval p3 between VCSEL-B of the 3D shape measurement light source 20 is made wider than the interval p2 between VCSEL-A of the proximity detection light source 10 (p3>p2), temperature rise can be suppressed. On the other hand, since the VCSEL-A of the proximity detection light source 10 has a smaller optical output than the VCSEL-B of the 3D shape measurement light source 20, the temperature does not easily rise. Therefore, if the distance p2, which is the distance between VCSEL-A of the light source 10 for proximity detection, is made smaller than the distance p3, which is the distance between VCSEL-B of the light source 20 for 3D shape measurement, the occupation of the light source 10 for proximity detection is reduced. Easy to reduce area.

Furthermore, as shown in FIG. 8(a), it is preferable that the first region 30A of the diffusion plate 30 be surrounded on all sides by the second region 30B. By doing this, the light emitted from the VCSEL-B of the 3D shape measurement light source 20 passes through the first region of the diffuser plate 30, as compared with FIGS. 9(a) and 9(b) described later. It is restrained from doing so.

Next, a modification of the diffusion plate 30 will be described.
FIG. 9 is a diagram showing a modification of the diffusion plate 30. 9(a) shows a first modified example of the diffusion plate 30, and FIG. 9(b) shows a second modified example of the diffused plate 30.
In a first modified example of the diffuser plate 30 shown in FIG. 9(a), the planar shape of the first region 30A of the diffuser plate 30 is made into a slit shape extending in the +x direction. By doing this, the margin for the arrangement in the ±x direction is widened. Even in this case, since the first region is surrounded by the second region, the light emitted from the VCSEL-B of the 3D shape measurement light source 20 passes through the first region of the diffuser plate 30. It is restrained from doing so.

On the other hand, in a second modified example of the diffuser plate 30 shown in FIG. 9(b), the first region 30A of the diffuser plate 30 is provided at the right end (+x direction side) of the diffuser plate 30. In this way, the first region is not surrounded by the second region, so compared to the first modification of the diffuser plate 30, the light emitted from the VCSEL-B of the 3D shape measurement light source 20 is Among them, the amount of light passing through the first region 30A of the diffuser plate 30 increases. However, when the optical output of the VCSEL-B of the 3D shape measurement light source 20 is small, or when the distance between the VCSEL-B of the 3D shape measurement light source 20 and the first region 30A is large in plan view, etc. In a configuration in which the light emitted from the VCSEL-B of the 3D shape measurement light source 20 is allowed to pass through the first region 30A, the second modification of the diffuser plate 30 may be adopted. The light emitted from the VCSEL-B of the 3D shape measurement light source 20 is suppressed from passing through the first region of the diffuser plate 30.
Here, the phrase "the first region is surrounded by the second region" means that the second region 30B exists in at least two directions when viewed from above.

(Configuration of 3D sensor 6)
FIG. 10 is a diagram illustrating the 3D sensor 6.
The 3D sensor 6 is configured with a plurality of light receiving areas 61 arranged in a matrix (lattice). The 3D sensor 6 receives a light reception pulse that is reflected light from the object to be measured in response to the light pulse emitted from the light emitting device 4, and accumulates charges corresponding to the time until the light is received in each light reception area 61. As an example, the 3D sensor 6 is configured as a device with a CMOS structure in which each light receiving region 61 includes two gates and a charge storage section corresponding thereto. By applying pulses alternately to the two gates, the generated photoelectrons are transferred to either of the two charge storage sections at high speed, and charges are accumulated according to the phase difference between the emitted light pulse and the received light pulse. It is composed of Then, a digital value corresponding to the charge corresponding to the phase difference between the emitted light pulse and the received light pulse for each light receiving area 61 is outputted as a signal via the AD converter. That is, the 3D sensor 6 receives a signal corresponding to the time from when light is emitted from the light source 10 for proximity detection until it is received by the 3D sensor 6, and from when the light is emitted from the light source 20 for 3D shape measurement to when the 3D sensor 6, a signal corresponding to the time until light is received is output.

(Flowchart of authentication processing in information processing device 1)
FIG. 11 is a flowchart for performing authentication processing regarding use of the information processing device 1.
Here, the information processing device 1 is at least in an off state in which the power is off, a standby state in which power is supplied to only a part of the information processing device 1, and a standby state in which power is supplied to only a portion of the information processing device 1, and a state in which more parts than the standby state, for example, the information processing device 1 and an operating state in which power is supplied to the entire device.

First, it is determined whether or not there is a request to use the information processing device 1 (step 110, denoted as S110 in FIG. 11. The same applies to the others). The case where there is a use request refers to a case where the power is turned on in an off state, a case where an operation is performed by a user to use the information processing device 1 in a standby state, and the like. Further, an example of a case where there is a request for use is when a telephone call, e-mail, etc. is received in the standby state. That is, this corresponds to the case where the system control unit 9 receives a signal to shift to the operating state.
If a negative determination (NO) is made in step 110, that is, if the off state or standby state continues, step 110 is repeated.

On the other hand, if an affirmative determination (YES) is made in step 110, that is, if the state shifts to the operating state, the object to be measured is irradiated with light from the light source 10 for proximity detection, and the object to be measured is detected by the 3D sensor 6. Reflected light from an object is received (step 120). Note that the proximity detection light source 10 may continue to emit light in the standby state, regardless of whether or not there is a request for use in step 110.

Next, it is determined whether the object to be measured is nearby (step 130). Note that being close means that the object to be measured is within a predetermined distance. If a negative determination (NO) is made in step 130, that is, if the object to be measured is not close, the process returns to step 120.
On the other hand, if the determination in step 130 is affirmative (YES), that is, if the object to be measured is close, light is emitted from the 3D shape measurement light source 20, and the reflected light from the object to be measured is emitted. The light is received by the 3D sensor 6 (step 140). At this time, the light irradiation from the proximity detection light source 10 may be stopped, or the light irradiation may be continued. If the irradiation from the proximity detection light source 10 is continued, the irradiation pattern on the irradiation surface tends to be more uniform than when the irradiation is not continued.

Then, based on the amount of light received by the 3D sensor 6, the shape identifying section 81 of the optical device control section 8 identifies the 3D shape of the object to be measured (step 150).

Next, it is determined whether the 3D shape that is the identification result identified by the authentication processing unit 91 is a predetermined shape (step 160). If the determination in step 160 is affirmative (YES), that is, if the identified 3D shape is a predetermined shape, use of the own device (information processing device 1) is permitted (step 170 ). On the other hand, if a negative determination (NO) is made in step 160, that is, if the identified 3D shape is not a shape stored in advance in a ROM or the like, use of the information processing device 1, which is the own device, is not permitted. Then, the process returns to step 120. Note that, in addition to the 3D shape, other information such as a two-dimensional image acquired by the 2D camera 93 may be taken into consideration to determine permission to use the information processing device 1, which is the own device.

As described above, the information processing device 1 in this embodiment includes the proximity detection light source 10 and the 3D shape measurement light source 20. This determines whether the object to be measured is close to the information processing device 1 by irradiating light from the light source 10 for proximity detection, and if the object to be measured is close, the light source 20 for 3D shape measurement Light for 3D measurement is irradiated from. That is, the 3D shape measurement light source 20 is suppressed from emitting light even though the object to be measured is not close to each other. Moreover, at this time, power consumption is suppressed by making the light output of the light source 10 for proximity detection smaller than the light output of the light source 20 for 3D shape measurement. That is, when the information processing device 1 is a portable information processing terminal, a decrease in the amount of charge of the battery is suppressed.

(Connection relationship between the proximity detection light source 10 and the 3D shape measurement light source 20 and the circuit board 7)
Next, the connection relationship between the proximity detection light source 10, the 3D shape measurement light source 20, and the conductor pattern provided on the circuit board 7 will be explained with reference to FIG.
On the circuit board 7, a cathode pattern 71 for the proximity detection light source 10, an anode pattern 72, a cathode pattern 73 for the 3D shape measurement light source 20, and anode patterns 74A and 74B are provided as conductor patterns.

As described above, the proximity detection light source 10 is provided with the cathode electrode 114 on the back surface and the anode electrode 118 on the front surface (see FIG. 5). Note that the anode electrode 118 connects the p-side electrodes 112 of the four VCSEL-A and also includes a pad portion 118A to which a bonding wire 76, which will be described later, is connected.
Similarly, the 3D shape measurement light source 20 is provided with a cathode electrode 214 on the back surface and an anode electrode 218 on the front surface (see FIG. 6). Note that the anode electrode 218 is formed to connect the anode electrodes 218 of the VCSEL-B arranged in a matrix, is extended in the ±y direction, and is a pad to which bonding wires 75A and 75B, which will be described later, are connected. 218A and 218B.

The cathode pattern 71 for the proximity detection light source 10 is formed to have a wider area than the proximity detection light source 10 so that the cathode electrode 114 provided on the back surface of the proximity detection light source 10 is connected. In the proximity detection light source 10, a cathode electrode 114 provided on the back surface and a cathode pattern 71 for the proximity detection light source 10 on the circuit board 7 are bonded with a conductive adhesive. The pad portion 118A of the anode electrode 118 of the proximity detection light source 10 is connected to the anode pattern 72 on the circuit board 7 with a bonding wire 76.

Similarly, the cathode pattern 73 for the 3D shape measurement light source 20 is formed to have a wider area than the 3D shape measurement light source 20 so that the cathode electrode 214 provided on the back surface of the 3D shape measurement light source 20 is connected. ing. The 3D shape measurement light source 20 is bonded onto the cathode pattern 73 for the 3D shape measurement light source 20 using a conductive adhesive or the like.
The anode patterns 74A and 74B for the 3D shape measurement light source 20 are arranged so as to face two opposing sides (±y direction sides) of the anode electrode 218 (see FIG. 6) provided on the surface of the 3D shape measurement light source 20. It is set in. The anode patterns 74A, 74B and the pad portions 218A, 218B of the anode electrode 218 of the 3D shape measurement light source 20 are connected by bonding wires 75A, 75B, respectively. Note that, although a plurality of bonding wires 75A and 75B are each provided, one of them is given a reference numeral.

(Drive method)
If it is desired to drive the proximity detection light source 10 and the 3D shape measurement light source 20 at higher speeds, both may be driven on the low side. Low-side drive refers to a configuration in which a drive unit such as a MOS transistor is located downstream of a current path with respect to a drive target such as a VCSEL. Conversely, a configuration in which the drive section is located on the upstream side is called a high-side drive. In this embodiment, in order to drive both the proximity detection light source 10 and the 3D shape measurement light source 20 on the low side, their cathodes are separated and driven independently.

FIG. 12 is a diagram illustrating low-side drive. In FIG. 12, the relationship between the VCSEL-A of the proximity detection light source 10, the VCSEL-B of the 3D shape measurement light source 20, the first drive section 50A, the second drive section 50B, and the optical device control section 8 is shown. shows. The first drive section 50A and the second drive section 50B are grounded via a MOS transistor. That is, the VCSEL is driven on the low side by turning on/off the MOS transistor.
In FIG. 12, the VCSEL-A of the proximity detection light source 10 and the VCSEL-B of the 3D shape measurement light source 20 are also separated on the anode side.

(Arrangement of proximity detection light source 10, 3D shape measurement light source 20, and light receiving element 40 for light amount monitoring in light emitting device 4)
FIG. 13 is a diagram illustrating the arrangement of the proximity detection light source 10, the 3D shape measurement light source 20, and the light receiving element 40 for light amount monitoring in the light emitting device 4. 13(a) shows the arrangement described in this embodiment, FIG. 13(b) shows a first modification of the arrangement, and FIG. 13(c) shows a second modification of the arrangement. (d) is a third modification of the arrangement. Here, the light source 10 for proximity detection, the light source 20 for 3D shape measurement, the light receiving element 40 for monitoring light amount, and the bonding wire are shown, and other descriptions are omitted. In addition, in the 3D shape measuring light source 20 having a rectangular planar shape, the side surface in the −x direction is referred to as a side surface 21A, the side surface in the +x direction is referred to as a side surface 21B, the side surface in the +y direction is referred to as a side surface 21C, and the side surface in the −y direction is referred to as a side surface 21D. . Here, side surface 21A and side surface 21B face each other, and side surface 21C and side surface 21D connect side surface 21A and side surface 21B and face each other.

In the arrangement described as this embodiment shown in FIG. 13(a) (see FIG. 3(a)), the light receiving element 40 for light amount monitoring is provided on the side surface 21A of the 3D shape measuring light source 20 in the −x direction. ing. The proximity detection light source 10 is provided on the +x direction side surface 21B side of the 3D shape measurement light source 20. The bonding wires 75A and 75B connecting the anode electrode 218 (see FIG. 6) of the 3D shape measurement light source 20 and the anode patterns 74A and 74B (see FIG. 4) provided on the circuit board 7 are connected to the 3D shape measurement light source 20. They are provided so as to face the side surfaces 21C and 21D of 20 in the ±y direction.

By doing so, current is supplied to each VCSEL-B of the 3D shape measurement light source 20 symmetrically from the ±y direction of the 3D shape measurement light source 20. Therefore, compared to the third comparative example shown in FIG. 13(d), which will be described later, it is easier to supply current to each VCSEL-B of the 3D shape measurement light source 20 more evenly.

No bonding wire is provided on the side surface 21A in the −x direction of the 3D shape measuring light source 20 where the light receiving element 40 for monitoring the amount of light is disposed. Therefore, it is easy to arrange the light receiving element 40 for monitoring the amount of light in close proximity to the light source 20 for 3D shape measurement. Therefore, in comparison with a second comparative example shown in FIG. Easy to receive light.

In the first modification of the arrangement shown in FIG. 13(b), the light receiving element 40 for light amount monitoring is placed on the side surface 21B of the 3D shape measurement light source 20 in the +x direction and outside the proximity detection light source 10. has been done. That is, the distance between the 3D shape measurement light source 20 and the light receiving element 40 for light amount monitoring is longer than the arrangement in this embodiment shown in FIG. 13(a). Therefore, of the light emitted from the 3D shape measurement light source 20, the amount of light reflected by the diffuser plate 30 is reduced. That is, it becomes difficult to receive the light reflected by the diffuser plate 30. Therefore, there is a possibility that detection accuracy may be reduced.

In the second modification of the arrangement shown in FIG. 13(c), the light receiving element 40 for light amount monitoring is located on the +x direction side surface 21B side of the light source 20 for 3D shape measurement, and detects proximity to the light source 20 for 3D shape measurement. and the light source 10 for use. Therefore, it is easy to arrange the light receiving element 40 for monitoring the amount of light in close proximity to the light source 20 for 3D shape measurement. Therefore, as in FIG. 13(a) described above, current is more easily supplied evenly to each VCSEL-B of the light source 20 for 3D shape measurement, and the light receiving element 40 for light amount monitoring is used for 3D shape measurement. Of the light emitted from the light source 20, the light reflected by the diffuser plate 30 is easily received.

In the third modification of the arrangement shown in FIG. 13(d), the bonding wire 75A in FIG. 13(a) is not provided. Instead, a separate anode pattern is provided on the circuit board 7 on the -x direction side surface 21A side of the 3D shape measurement light source 20, and a separate anode pattern is provided on the anode electrode 218 of the 3D shape measurement light source 20 and the circuit board 7. A bonding wire 75C is provided for connecting the anode pattern. Note that, although a plurality of bonding wires 75C are provided, one of them is given a reference numeral.

The proximity detection light source 10 is provided on the -y direction side surface 21D side of the 3D shape measurement light source 20, and the light receiving element 40 for light amount monitoring is provided on the +x direction side surface 21B side of the 3D shape measurement light source 20. There is. In this way, the 3D shape measuring light source 20 and the light receiving element 40 for monitoring the amount of light are arranged close to each other. However, since current is supplied to the VCSEL-B of the 3D shape measurement light source 20 from two sides, the side surface 21C side in the +y direction and the side surface 21A side in the -x direction, each VCSEL-B of the 3D shape measurement light source 20 - It is difficult to uniformly flow current to B. Therefore, the third modification is preferably used in specifications where the influence is small even if the current does not flow uniformly.

In the configuration described above, the light emitting device 4 and the 3D sensor 6 are arranged on the common circuit board 7, but they may be arranged on different circuit boards. Furthermore, in the light emitting device 4, at least the proximity detection light source 10, the 3D shape measurement light source 20, the diffusion plate 30, and the spacer 33 are provided on a board different from the circuit board 7, and these are integrated into one light emitting component (module). ), it may be configured to be connectable to the circuit board 7 on which the first drive unit 50A, the second drive unit 50B, the 3D sensor 6, etc. are mounted. As an example, the maximum external shape of the light emitting component may be defined by the diffuser plate 30, spacer 33, and substrate that cover the proximity detection light source 10 and the 3D shape measurement light source 20. With such a configuration, this light emitting component is not equipped with the first drive section 50A, the second drive section 50B, the 3D sensor 6, etc., and is therefore provided and distributed as a small component. In addition, since the light source 10 for proximity detection and the light source 20 for 3D shape measurement are sealed by being surrounded by the diffuser plate 30, spacer 33, and substrate, they are dust-proof, moisture-proof, etc. compared to a case where they are not sealed. can be measured. Note that the light-emitting component may or may not include the light-receiving element 40 for monitoring the amount of light.

Moreover, the light source 10 for proximity detection in the above configuration does not necessarily need to be used in combination with the light source 20 for 3D shape measurement. For example, the proximity detection light source 10 may be provided alone as a distance measurement light source, regardless of whether a 3D shape is to be measured. That is, it may be provided as a single vertical cavity surface emitting laser element array having a plurality of long resonator structures connected in parallel to each other. In such a configuration, by driving in a range lower than the range where the power conversion efficiency can be maximized (for example, 4 mW to 8 mW), only one surface emitting laser element can be driven in the range where the power conversion efficiency can be maximized. Compared to the case, the light density is increased while suppressing the increase in the divergence angle. Therefore, especially in a configuration in which the viewing range of the light receiving section is narrow and a wider range than the viewing range of the light receiving section on the irradiation surface is irradiated, light is received with a higher SN ratio.

Further, the proximity detection light source 10 having the above configuration may be applied not only to a light source for distance measurement, but also to a light source for other uses in which it is desired to increase light density while suppressing an increase in the divergence angle.

DESCRIPTION OF SYMBOLS 1... Information processing device, 2... User interface (UI) part, 3... Optical device, 4... Light emitting device, 6... 3D sensor, 7... Circuit board, 8... Optical device control part, 9... System control part, 10... Proximity detection light source, 20... Light source for 3D shape measurement, 30... Diffusion plate, 30A... First region, 30B... Second region, 33... Spacer, 40... Light receiving element for light amount monitoring, 50A... First drive 50B...Second driving unit, 61...Light receiving area, 81...Shape identification unit, 91...Authentication processing unit, VCSEL, VCSEL-A, VCSEL-B...Vertical cavity surface emitting laser element

Claims (10)

a first light source that oscillates in a single transverse mode;
a second light source that oscillates in multiple transverse modes and has a higher optical output than the first light source and is configured to be driven independently of the first light source;
a light receiving unit that receives a first reflected light emitted from the first light source and reflected by the object to be measured, and a second reflected light emitted from the second light source and reflected by the object to be measured; Equipped with
The second light source emits light via a light diffusion member provided on the emission path of the second light source,
An optical device that emits light from the second light source when the first reflected light is light indicating that the object to be measured is present within a predetermined distance. a first light source that oscillates in a single transverse mode;
a second light source that oscillates in multiple transverse modes and has a higher optical output than the first light source and is configured to be driven independently of the first light source;
a light receiving unit that receives a first reflected light emitted from the first light source and reflected by the object to be measured, and a second reflected light emitted from the second light source and reflected by the object to be measured;
a control unit configured to use the first reflected light to check whether or not the object to be measured exists within a predetermined distance, and control the object to be measured using the second reflected light ;
The second light source emits light via a light diffusing member provided on the emission path of the second light source.
optical equipment. The first light source includes at least one first vertical cavity surface emitting laser device, the second light source includes a plurality of second vertical cavity surface emitting laser devices,
The first vertical cavity surface emitting laser element is driven such that the optical output emitted from the single vertical cavity surface emitting laser element is smaller than the optical output emitted from the second vertical cavity surface emitting laser element. Item 2. The optical device according to item 1 or 2. The first light source includes at least one first vertical cavity surface emitting laser device, the second light source includes a plurality of second vertical cavity surface emitting laser devices,
The optical device according to claim 1 or 2, wherein the optical device is driven with an optical output such that the power conversion efficiency of the first vertical cavity surface emitting laser element is lower than the power conversion efficiency of the second vertical cavity surface emitting laser element. . 5. The first vertical cavity surface emitting laser element is driven such that the optical output of one first vertical cavity surface emitting laser element is in the range of 1 mW to 4 mW. optical equipment. Any one of claims 3 to 5, wherein the second vertical cavity surface emitting laser element is driven such that the optical output of one second vertical cavity surface emitting laser element is in the range of 4 mW to 8 mW. The optical device according to item 1. 7. The first vertical cavity surface emitting laser element has a long cavity structure having a cavity length of 5λ to 20λ, where λ is the oscillation wavelength. optical equipment. The light receiving section receives a signal corresponding to the time from when light is emitted from the first light source to when the light is received by the light receiving section, and from when the light is emitted from the second light source until it is received by the light receiving section. 3. The optical device according to claim 1, wherein the optical device outputs a signal corresponding to the time until the optical device is activated. The optical device according to any one of claims 1 to 8,
a shape identifying unit that identifies a three-dimensional shape of the object to be measured based on second reflected light emitted from a second light source included in the optical device and reflected by the object;
An information processing device comprising: an authentication processing unit that performs authentication processing regarding use of the own device based on the identification result of the shape identification unit;
The information processing device according to claim 9, comprising: