JP2020174096A - Light-emitting device, optical device, and information processor - Google Patents

Abstract

To provide a light-emitting device, having a first light source and a second light source which has a higher optical output than the first light source and is structured to be driven independently of the first light source, the light-emitting device being capable of suppressing degradation in optical density at an irradiation surface in the light emitted from the first light source, as compared to a structure irradiating light from the first light source at the same spread angle as that of the second light source used for diffusion irradiation.SOLUTION: A light-emitting device 4 includes: a light source 10 for proximity detection which oscillates in a single transverse mode; a light source 20 for 3D shape measurement which has a higher optical output than the light source 10 for proximity detection, is structured to be driven independently of the light source 10 for proximity detection and oscillates in a multiple transverse mode; and a diffuser panel 30 mounted on an emission route of the light source 20 for 3D shape measurement.SELECTED DRAWING: Figure 3

Description

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

Patent Document 1 has a light source, a plurality of lenses arranged adjacent to each other on a predetermined plane, a diffuser plate for diffusing the light emitted by the light source, and light diffused by the diffuser plate as a subject. An imaging device including an imaging element that receives the reflected reflected light and a plurality of lenses arranged so that the period of interference fringes in the diffused light is three pixels or less is described.

JP-A-2018-54769

By the way, there is known a configuration 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 and the like, the light diffusing member emits light having a higher light output than the light source for proximity detection that detects whether or not the object to be measured is within a predetermined distance and the light source for proximity detection. It is conceivable to include a light source for three-dimensional measurement that diffusely irradiates the object to be measured via the like.
Here, as the light source for proximity detection, it is desired that the spread angle is not too wide so that the light density does not decrease too much on the irradiation surface of the object to be measured. On the other hand, as a light source for three-dimensional measurement, it is not desired that the spreading angle is narrow because diffuse irradiation is performed by a light diffusing member or the like, but rather a high light output is desired.

The present invention is used for diffuse irradiation in a configuration having a first light source and a second light source having a higher light output than the first light source and configured to be driven independently of the first light source. Compared with the configuration in which the light is emitted from the first light source at the same spread angle as the spread angle of the second light source, the decrease in the light density of the light emitted from the first light source on the irradiation surface is suppressed. Provide a light source and the like.

The invention according to claim 1 is configured to drive the first light source oscillating in a single transverse mode, which has a larger light output than the first light source and is driven independently of the first light source. It is a light emitting device including a second light source that oscillates in the multiple transverse mode and a light diffusing member provided on the emission path of the second light source.
In the invention according to claim 2, the first light source includes at least one or more first vertical cavity surface emitting laser elements, and the second light source includes a plurality of second vertical resonator surface emitting laser elements. The light output from the first vertical resonator surface emitting laser element including the laser element is smaller than the light output emitted from the second vertical resonator surface emitting laser element. The light emitting device according to claim 1, which is driven by the above.
According to the third aspect of the present invention, the first light source includes at least one or more first vertical resonator surface emitting laser elements, and the second light source includes a plurality of second vertical resonator surface emitting laser elements. The first aspect of claim 1, wherein the laser element is included and driven by an optical output in which the power conversion efficiency of the first vertical resonator surface emitting laser element is lower than the power conversion efficiency of the second vertical resonator surface emitting laser element. It is a light emitting device of.
According to the fourth aspect of the present invention, the first vertical resonator surface emitting laser element is driven so that the light output of one of the first vertical resonator surface emitting laser elements is in the range of 1 mW to 4 mW. The light emitting device according to claim 2 or 3.
According to the fifth aspect of the present invention, the second vertical resonator surface emitting laser element is driven so that the light output of one of the second vertical resonator surface emitting laser elements is in the range of 4 mW to 8 mW. The light emitting device according to any one of claims 2 to 4.
The invention according to claim 6 is a long resonator structure in which the first vertical resonator surface emitting laser element has a resonator length of 5λ to 20λ when the oscillation wavelength is λ. The light emitting device according to any one of 5.
The invention according to claim 7 is the first reflected light emitted from the light emitting device according to any one of claims 1 to 6 and the first light source included in the light emitting device and reflected by the object to be measured. And a light receiving unit that receives the second reflected light emitted from the second light source included in the light emitting device and reflected by the object to be measured, and the light receiving unit receives light from the first light source. Optical that outputs a signal corresponding to the time from the emission to the light reception by the light receiving unit and a signal corresponding to the time from the light emission from the second light source to the light reception by the light receiving unit. It is a device.
The invention according to claim 8 is the first reflected light emitted from the light emitting device according to any one of claims 1 to 6 and the first light source included in the light emitting device and reflected by the object to be measured. , And a light receiving unit that receives the second reflected light emitted from the second light source included in the light emitting device and reflected by the object to be measured, and the first reflected light is the object to be measured. When the light indicates that it exists within a predetermined distance, it is an optical device that emits light from the second light source.
The invention according to claim 9 is based on the optical device according to claim 7 or 8 and the second reflected light emitted from the second light source included in the optical device and reflected by the object to be measured. It is an information processing apparatus including a shape specifying unit for specifying a three-dimensional shape of a measured object.
The information processing device according to claim 10, further comprising an authentication processing unit that performs an authentication process relating to the use of the own device based on the specific result of the shape specifying unit.

According to the invention of claim 1, the light is emitted from the first light source as compared with the configuration in which the light is emitted from the first light source at the same spread angle as the spread angle of the second light source used for diffuse irradiation. The decrease in light density on the light irradiation surface is suppressed.
According to the second aspect of the invention, the first vertical is compared with the case where the light output of the first vertical resonator surface emitting laser element is matched with the light output of the second vertical resonator surface emitting laser element. Resonator surface emission The decrease in light density on the irradiation surface of the light emitted from the laser element is suppressed.
According to the third aspect of the invention, the power conversion efficiency of the first vertical resonator surface emitting laser element is compared with the power conversion efficiency of the second vertical resonator surface emitting laser element. The decrease in light density on the irradiation surface of the light emitted from the vertical resonator surface emitting laser element is suppressed.
According to the invention of claim 4, light with a narrow spread angle is irradiated as compared with the case where the light is driven in a region exceeding 4 mW.
According to the fifth aspect of the present invention, the power conversion efficiency of the second vertical resonator surface emitting laser element is improved as compared with the case where the laser element is driven in a region of less than 4 mW.
According to the sixth aspect of the present invention, the spread angle is narrower as compared with the case where the resonator is composed of a normal single-mode vertical resonator surface emitting laser element having the same resonator length as λ.
According to the invention of claim 7, an optical device capable of performing both proximity detection and three-dimensional measurement is provided.
According to the eighth aspect of the invention, light is not emitted from the second light source when the object to be measured does not exist within a predetermined distance.
According to the invention of claim 9, an information processing apparatus capable of measuring a three-dimensional shape is provided.
According to the invention of claim 10, an information processing apparatus equipped with an authentication process based on a three-dimensional shape is provided.

It is a figure which shows an example of the information processing apparatus to which this embodiment is applied. It is a block diagram explaining the structure of an information processing apparatus. It is an example of a plan view and a sectional view of an optical device. (A) is a plan view, and (b) is a cross-sectional view taken along the line IIIB-IIIB of (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 the proximity detection light source. It is a figure explaining the cross-sectional structure of one VCSEL in the light source for 3D shape measurement. It is a figure explaining the relationship between the optical output of a general VCSEL and the power conversion efficiency. It is a figure explaining an example of the structure of a diffuser plate. (A) is a plan view, and (b) is a cross-sectional view taken along the line VIIIB-VIIIB of (a). It is a figure which shows the modification of the 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 3D sensor. It is a flowchart for performing the authentication process concerning the use of an information processing apparatus. 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 amount monitoring in a light emitting device. (A) is the arrangement described as the present 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.
The information processing device is its own device only when it identifies whether or not the user who has accessed the information processing device is permitted to access it and is authenticated as a user who is permitted to access the information processing device. In many cases, the use of information processing equipment is permitted. So far, a method of authenticating a user by a password, a fingerprint, an iris, or the like has been used. Recently, there is a demand for an authentication method with even higher security. As this method, authentication by a three-dimensional image such as the shape of the user's face is performed.
Here, the information processing device will be described as an example of a portable information processing terminal, and will be described as authenticating a user by recognizing the shape of a face captured as a three-dimensional image. The information processing device can be applied to an information processing device such as a personal computer (PC) other than a portable information processing terminal.
Further, the configuration, function, method and the like described in the present embodiment can be applied not only to the recognition of the shape of the face but also to the recognition of the three-dimensional shape of the object. That is, an object other than the face may be used as an object to be measured and applied to the recognition of its shape. Moreover, 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 the present 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 unit (hereinafter, referred to as a UI unit) 2 and an optical device 3 for acquiring 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 by the user's operation. 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 acquire a three-dimensional image. The 3D sensor 6 acquires the light emitted by the light emitting device 4 and reflected by the face and returned. Here, it is assumed that a three-dimensional image of a face is acquired based on the so-called TOF (Time of Flight) method based on the flight time of light. In the following, even when the face is the object to be measured, it is referred to as the object to be measured.

The information processing device 1 is configured as a computer including a CPU, ROM, RAM, and the like. The ROM includes a non-volatile rewritable memory, for example, a flash memory. Then, the programs and constants stored in the ROM are expanded in the RAM and executed by the CPU, so that the information processing device 1 operates and various types of information processing are executed.

FIG. 2 is a block diagram illustrating the configuration of the information processing device 1.
The information processing device 1 includes the above-mentioned optical device 3, an optical device control unit 8, and a system control unit 9. The optical device 3 includes a light emitting device 4 and a 3D sensor 6 as described above. The optical device control unit 8 controls the optical device 3. The optical device control unit 8 includes a shape specifying unit 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. A UI unit 2, a speaker 92, a two-dimensional (2D) camera 93, and the like are connected to the system control unit 9. The 3D sensor 6 is an example of a light receiving unit.
Hereinafter, they will be described in order.

The optical device 3 includes a light emitting device 4 and a 3D sensor 6 as described above. The light emitting device 4 includes a proximity detection light source 10, a 3D shape measurement light source 20, a diffuser plate 30, a light quantity monitoring light receiving element (referred to as PD in FIG. 2) 40, and a first drive unit 50A. And a second drive unit 50B. 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 diffuser 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 so as to emit pulsed light of several tens of MHz to several hundreds of MHz (hereinafter, referred to as an emitted light pulse).
Then, as will be described later, in the optical device 3, the 3D sensor 6 transmits the reflected light from the object to be measured with respect to the light emitted from each of the proximity detection light source 10 and the 3D shape measurement light source 20 toward the object to be measured. It is configured to receive light.

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

The shape specifying 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 3D the object to be measured. Identify the shape.
The authentication processing unit 91 of the system control unit 9 relates to the use of the information processing device 1 when the 3D shape of the object to be measured, which is the specific result specified by the shape specifying unit 81, is a 3D shape stored in advance in a ROM or the like. Perform authentication processing. The authentication process relating to the use of the information processing device 1 is, for example, a process of whether or not to permit the use of the information processing device 1 which is its own device. For example, when the 3D shape of the face to be measured matches the face shape stored in a storage member such as a ROM, the information processing device 1 is its own device including various applications provided by the information processing device 1. Is allowed to be used.
The shape specifying unit 81 and the authentication processing unit 91 are configured by a program as an example. Further, it may be composed of an integrated circuit such as an ASIC or FPGA. Further, it may be composed of software such as a program and an integrated circuit.

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

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

As shown in FIG. 3A, in the optical device 3, the light emitting device 4 and the 3D sensor 6 are arranged in the x direction on the circuit board 7. The circuit board 7 uses a plate-shaped member made of an insulating material as a base material, and is provided with a conductor pattern made of a conductive material. The insulating material is composed of, for example, ceramic or epoxy resin. A conductor pattern made of a conductive material is provided on the circuit board 7. 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 substrate having a conductor pattern provided on the surface thereof, or may be a multilayer substrate having a plurality of layers of conductor patterns. Further, the light emitting device 4 and the 3D sensor 6 may be arranged on different circuit boards.

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

The proximity detection light source 10 and the 3D shape measurement light source 20 emit light in the same direction (the z direction in FIG. 3B) when they are viewed in a plan view, that is, the plane shape is a quadrangle. The plane shape of the proximity detection light source 10 and the 3D shape measurement light source 20 does 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 the circuit board 7 may be interposed between the heat dissipation base materials such as aluminum oxide and aluminum nitride. It may be mounted on top. Hereinafter, the proximity detection light source 10 and the 3D shape measurement light source 20 will be described as being directly mounted on the circuit board 7. Here, the plan view means viewing from the z direction in FIG. 3A. The same applies hereinafter.

The first drive unit 50A for driving the proximity detection light source 10 and the second drive unit 50B for driving 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 unit 50A is set to be smaller than the rated output of the second drive unit 50B. Therefore, the outer size of the first drive unit 50A is smaller than that of the second drive unit 50B. Since the second drive unit 50B needs to drive the 3D shape measurement light source 20 with a large current, the second drive unit 50B is preferentially arranged over the first drive unit 50A so that the distance from 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 unit 50A is arranged at a position laterally displaced from the second drive unit 50B, that is, on the + y direction side of the second drive unit 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 intensity monitoring light receiving element 40 is located on the circuit board 7 at a position close to the 3D shape measurement light source 20, that is, a position where the second drive unit 50B is arranged with respect to the 3D shape measurement light source 20. It is located on the opposite side of. By arranging the proximity detection light source 10, the 3D shape measurement light source 20, and the light amount monitoring light receiving element 40 close to each other in this way, it becomes easy to cover these parts with the common diffuser plate 30. On the contrary, when the proximity detection light source 10 and the 3D shape measurement light source 20 are arranged at a distance, if they are covered with a common diffuser plate 30, a large-sized diffuser plate 30 is required.

As shown in FIG. 3A, the diffuser plate 30 has a rectangular planar shape as an example. The plane shape of the diffuser plate 30 does not have to be rectangular. Then, as shown in FIG. 3B, the diffuser plate 30 is supported by the spacer 33 on the light emission direction side of the proximity detection light source 10 and the 3D shape measurement light source 20, and the proximity detection light source 10 and the 3D shape. It is provided at a predetermined distance from the measurement light source 20. The diffuser plate 30 is provided so as to cover the proximity detection light source 10, the 3D shape measurement light source 20, and the light amount monitoring light receiving element 40. 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 amount monitoring light receiving element 40. When the spacer 33 is composed 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 are emitted via the spacer 33. It is suppressed that the light source is emitted to the outside. Further, by sealing the proximity detection light source 10, the 3D shape measurement light source 20, and the like with the diffusion plate 30 and the spacer 33, dustproof, moistureproof, and the like can be obtained. In the present embodiment, by arranging the proximity detection light source 10, the 3D shape measurement light source 20, and the light amount monitoring light receiving element 40 in close proximity, it becomes easy to surround the spacer 33 with a small size. On the contrary, when the proximity detection light source 10 and the 3D shape measurement light source 20 are arranged at a distance, if they are surrounded by a common spacer 33, a spacer 33 having a large size is required. Further, it is conceivable to prepare two spacers 33 having a small size and surround the proximity detection light source 10 and the 3D shape measurement light source 20 separately, but the number of parts is doubled. Further, the spacer 33 is not provided between the proximity detection light source 10 and the 3D shape measurement light source 20. Therefore, the light emitting device 4 is downsized as compared with the configuration in which the spacer 33 is provided between them.

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

The light source 20 for 3D shape measurement maintains a predetermined light output by the second drive unit 50B via the optical device control unit 8 according to the amount of light received (light reception amount) by the light amount monitoring light receiving element 40. Is controlled.

Further, when the light receiving amount of the light amount monitoring light receiving element 40 is extremely reduced, the diffuser plate 30 is detached or damaged, and the light emitted by the 3D shape measuring light source 20 is directly irradiated to the outside. There is a risk of being there. In such a case, the light 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 driving 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 light source 20 for measuring the 3D shape to emit light for measuring the 3D shape of the object to be measured. Then, the light quantity monitoring light receiving element 40 receives the light reflected by the diffuser plate 30 among the light emitted by the 3D shape measuring light source 20, and monitors the light output of the 3D shape measuring light source 20. Then, the light output of the 3D shape measurement light source 20 is controlled via the second drive unit 50B based on the light output of the 3D shape measurement light source 20 monitored by the light amount monitoring light receiving element 40. The light intensity monitoring light receiving element 40 may monitor the light output of the proximity detection light source 10 in the same manner as the 3D shape measurement light source 20.

(Structure of light source 10 for proximity detection and light source 20 for 3D shape measurement)
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 light source 20 for 3D shape measurement includes a vertical cavity surface emitting laser element VCSEL-B. Hereinafter, the vertical cavity surface emitting laser element VCSEL-A is referred to as VCSEL-A, and the vertical resonator surface emitting laser element VCSEL-B is referred to as VCSEL-B. When VCSEL-A and VCSEL-B are not distinguished, they are referred to as VCSEL. VCSEL-A is an example of a first vertical cavity surface emitting laser element, and VCSEL-B is an example of a second vertical cavity surface emitting laser element.

Since the VCSEL is a light emitting element in which an active region serving as a light emitting region is provided between the lower multilayer film reflector and the upper multilayer film reflecting mirror laminated on the substrate and emits laser light in the direction perpendicular to the substrate. It is easy to make an array arranged in a dimension. 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 or not 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 1 m. The range for measuring the 3D shape of the object to be measured (hereinafter, referred to as a measurement range or an 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 proximity detection light source 10 is 1 to 50, and the number of VCSEL-B of the 3D shape measurement light source 20 is 100 to 1000. That is, the number of VCSEL-Bs of the 3D shape measurement light source 20 is larger than the number of VCSEL-As 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. Similarly, the plurality of VCSEL-Bs of the 3D shape measurement light source 20 are also connected in parallel to each other and driven in parallel. The number of VCSELs described above is an example, and may be set according to the measurement distance and the measurement range. The proximity detection light source 10 shown in FIG. 4 is configured to include four VCSEL-A as an example.

The proximity detection light source 10 does not need to irradiate the entire surface of the measurement range with light, and may detect whether or not the object to be measured is close to the measurement range. Therefore, the proximity detection light source 10 may irradiate a part of the measurement range with light. Therefore, the number of VCSEL-A of the proximity detection light source 10 may be small. Then, when there is a request to use the information processing device 1 in order to detect whether or not the object to be measured is close to the information processing device 1, the proximity detection light source 10 illuminates the measurement range at a predetermined cycle. 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 is close to the measurement range. Then, the 3D shape is specified from the reflected light received by the 3D sensor 6 from the measurement range. Therefore, the VCSEL-B of the light source 20 for 3D shape measurement is required to have a large amount of emitted light. A large number of VCSEL-Bs are included in order to uniformly irradiate the entire surface of the measurement range. Since the light source 20 for measuring the 3D shape emits light only when measuring the 3D shape, it is permissible even if the power consumption is high.

(Structure of VCSEL-A of light source 10 for proximity detection)
Next, the structure of the VCSEL-A of the proximity detection light source 10 will be described.
The proximity detection light source 10 irradiates light to detect whether or not the object to be measured is in close proximity. Therefore, the VCSEL-A of the proximity detection light source 10 should have a low output and a predetermined light density at a predetermined distance. That is, it is preferable that the light density is low and the light reflected from the object to be measured is reliably detected by the 3D sensor 6. Therefore, the VCSEL-A is required to have a small spread angle of the emitted light and a small decrease in the light density with respect to the distance.
The light density means the irradiance.

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

As the single mode VCSEL, a VCSEL having a long resonator structure may be used.
The VCSEL with a long resonator structure is a spacer of several λ to several tens of λ between the active region in the VCSEL of a general λ resonator structure in which the resonator length is the oscillation wavelength λ and one multilayer film reflector. By introducing a layer and lengthening the cavity length, the loss in the higher-order transverse mode is increased, which enables single-mode oscillation with an oxide aperture diameter larger than the oxidation aperture diameter of VCSEL with a general λ resonator structure. enable. In a VCSEL having a typical λ resonator structure, since the longitudinal mode interval (sometimes called a free spectrum range) is large, stable operation can be obtained in a single longitudinal mode. On the other hand, in the case of the VCSEL having a long cavity structure, the longitudinal mode interval becomes narrow due to the increase in the cavity length, and a plurality of standing waves in the longitudinal mode exist in the resonator. Switching between longitudinal modes is more likely to occur. For this reason, VCSELs with a long resonator structure are required to suppress switching between longitudinal modes.
The VCSEL having a long resonator structure is easier to set a narrower spread angle than the single mode VCSEL having a general λ resonator structure.

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

The n-type lower DBR102 is a multi-layer laminate consisting of a pair of Al _0.9 Ga _0.1 As layer and a GaAs layer, and the thickness of each layer is λ / 4 n _r (where λ is the oscillation wavelength and n _r is. Refractive index of the medium), and these are alternately laminated in 40 cycles. The carrier concentration after doping silicon, which is an n-type impurity, is, for example, 3 × 10 ¹⁸ cm ^-3 .

The resonator extension region 104 is a monolithic layer formed by a series of epitaxial growth. Therefore, the resonator extension region 104 is composed of AlGaAs, GaAs, or AlAs so that the lattice constants match or match with the GaAs substrate. Here, in order to emit laser light in the 940 nm band, the resonator extension region 104 is composed of AlGaAs that does not cause light absorption. The film thickness of the resonator extension region 104 is set to about 2 μm to 5 μm and the oscillation wavelength λ of 5λ to 20λ. Therefore, the moving distance of the carrier becomes long. Therefore, the resonator extension region 104 is preferably n-type having a large 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 having a large bandgap, for example, made of Al _0.9 Ga _0.1 As, 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, since the layer 120 that gives an optical loss that attenuates the oscillation intensity of the laser beam to some extent is inserted in the resonator extension region 104, the carrier block layer 105 plays a role of compensating for such loss. To bear. For example, the film thickness of the carrier block layer 105 is λ / 4 mn _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 GaAs barrier layer. It is an Al _0.6 Ga _0.4 As layer.

The p-type upper DBR108 is a laminate of a p-type Al _0.9 Ga _0.1 As layer and a GaAs layer, and the thickness of each layer is λ / 4 _nr , and these are alternately laminated for 29 cycles. is there. The carrier concentration after doping 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 on the uppermost layer of the upper DBR 108, and a current constriction layer 110 of p-type AlAs is formed on or inside the lowermost layer of the upper DBR 108.

By etching the semiconductor layers laminated from the upper DBR 108 to the lower DBR 102, a columnar mesa M1 is formed on the substrate 100, and the current constriction layer 110 is exposed on the side surface of the mesa M1. In the current constriction layer 110, a conductive region 110B surrounded by an oxidation region 110A and an oxidation region 110A selectively oxidized from the side surface of the mesa M1 is formed. The conductive region 110B is an oxidation aperture. In the oxidation step, the AlAs layer has a faster oxidation rate than the AlGaAs layer, and the oxidation region 110A is oxidized from the side surface of the mesa M1 toward the inside at a substantially constant rate, so that the plane shape is parallel to the substrate of the conductive region 110B. Has a shape that reflects the outer shape of the mesa M1, that is, a circular shape, and its center substantially coincides with the axial direction indicated by the alternate long and short dash line of the mesa M1. In the VCSEL-A having a long resonator structure, the diameter of the conductive region 110B for obtaining the single transverse mode can be made larger than that of the VCSEL having a normal λ resonator structure. For example, the diameter of the conductive region 110B is 7 μm. It can be increased up to about 8 μm.

An annular p-side electrode 112 made of metal in which Ti / Au or the like is laminated 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 is a light outlet 112A through which laser light is emitted to the outside. That is, the direction of the central axis of the mesa M1 is the optical axis. Further, a cathode electrode 114 is formed on the back surface of the substrate 100 as an n-side electrode. The surface of the upper DBR 108 including the light emission port 112A is the emission surface.

Then, the insulating layer 116 is provided so as to cover the surface of the mesa M1 except for the portion where the p-side electrode 112 and the anode electrode 118 described later are connected and the light emission port 112A. Then, except for the light emission port 112A, the anode electrode 118 is provided so as to make ohmic contact with the p-side electrode 112. The anode electrode 118 is provided except for the light emission port 112A of each of the plurality of VCSEL-A. That is, in the plurality of VCSEL-A of the proximity detection light source 10, each p-side electrode 112 is connected in parallel by the anode electrode 118.

In a VCSEL having a long cavity structure, since a plurality of longitudinal modes can exist in the reflection band defined by the resonator length, it is necessary to suppress switching or popping between the longitudinal modes. Here, the required longitudinal mode oscillation wavelength band is set to 940 nm, and in order to suppress switching to the other longitudinal mode oscillation wavelength bands, an unnecessary longitudinal mode standing wave is generated in the resonator extension region 104. A layer 120 that gives an optical loss is provided. That is, the layer 120 that gives the optical loss is introduced at the position of the required vertical mode standing wave node. The layer 120 that gives an 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 that gives the optical loss preferably has a higher impurity doping concentration than the semiconductor layer that constitutes the resonator extension region 104, and for example, the impurity concentration of AlGaAs that constitutes the resonator extension region 104 is 1 × 10 ¹⁷ When it is cm ^-3 , the layer 120 that gives an optical loss has an impurity concentration of 1 × 10 ¹⁸ cm ^-3 , and is configured to have an impurity concentration that is about an order of magnitude higher than that of other semiconductor layers. .. The higher the impurity concentration, the greater the absorption of light by the carriers, resulting in loss. The film thickness of the layer 120 that gives the optical loss is selected so that the loss to the required longitudinal mode is not large, and is preferably the same film thickness (10 nm) as the current constriction layer 110 located at the node of the standing wave. ~ 30 nm).

The layer 120, which provides the optical loss, is inserted so as to be located at the node for the required vertical mode standing wave. Since the standing wave node has a low intensity, the effect of the loss on the required longitudinal mode by the layer 120 that provides the optical loss is small. On the other hand, for an unwanted longitudinal mode standing wave, the layer 120, which provides optical loss, is located on the antinode other than the node. Since the antinode of the standing wave is stronger than the node, the loss given to the longitudinal mode in which the layer 120 giving the optical loss is unnecessary is large. In this way, by reducing the loss to the required longitudinal mode and increasing the loss to the unnecessary longitudinal mode, the unnecessary longitudinal mode is selectively prevented from resonating, and the longitudinal mode hopping is suppressed.

The layer 120 that gives the optical loss does not necessarily have to be provided at the position of each node of the required longitudinal mode standing wave in the cavity 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 that the layer 120 that gives an optical loss to the position of the node near the active region 106 may be formed. Further, if switching or popping between longitudinal modes is allowed, the layer 120 that gives an optical loss may not be provided.

(VCSEL-B of light source 20 for 3D shape measurement)
Next, the VCSEL-B of the light source 20 for 3D shape measurement will be described.
Here, the 3D shape measurement light source 20 irradiates light to specify the 3D shape of the object to be measured. Therefore, a predetermined light density is applied to a predetermined measurement range. Therefore, here, the VCSEL-B of the light source 20 for 3D shape measurement is preferably composed of a multi-mode VCSEL that tends to have a higher output than the single-mode VCSEL.

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

The VCSEL-B is an n-type lower DBR202 in which AlGaAs layers having different Al compositions are alternately laminated on a substrate 200 made of n-type GaAs, and an upper spacer layer and a lower spacer layer formed on the lower DBR202. The active region 206 including the quantum well layer sandwiched between the two, and the p-type upper DBR208 in which AlGaAs layers having different Al compositions formed on the active region 206 are alternately laminated are laminated. A p-type AlAs current constriction layer 210 is formed in or inside the lowermost layer of the upper DBR208.

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

By etching the semiconductor layers laminated from the upper DBR208 to the lower DBR202, a columnar mesa M2 is formed on the substrate 200, and the current constriction layer 210 is exposed on the side surface of the mesa M2. The current constriction layer 210 is formed with an oxidation region 210A selectively oxidized from the side surface of the mesa M2 and a conductive region 210B surrounded by the oxidation region 210A. The conductive region 210B is an oxidation 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 the center thereof substantially coincides with the axial direction indicated by the alternate long and short dash line of the mesa M2.

An annular p-side electrode 212 made of metal in which Ti / Au or the like is laminated is formed on the uppermost layer of the mesa M2, and the p-side electrode 212 is ohmic-connected to the contact layer of the upper DBR208. A circular light emitting port 212A whose center coincides with the axial direction of the mesa M2 is formed on the p-side electrode 212, and laser light is emitted to the outside from the light emitting port 212A. That is, the axial direction of the mesa M2 is the optical axis. Further, a cathode electrode 214 as an n-side electrode is formed on the back surface of the substrate 200. The surface of the upper DBR 208 including the light emission port 212A is the emission surface.

Then, the insulating layer 216 is provided so as to cover the surface of the mesa M2 except for the portion where the p-side electrode 212 and the anode electrode 218 described later are connected and the light emission port 212A. Then, except for the light emission port 212A, the anode electrode 218 is provided so as to make ohmic contact with the p-side electrode 212. The anode electrode 218 is provided except for the light emission port 212A of each of the plurality of VCSEL-Bs. That is, in the plurality of VCSEL-Bs constituting the 3D shape measurement light source 20, each p-side electrode 212 is connected in parallel by the anode electrode 218.

FIG. 7 is a diagram illustrating the relationship between the optical output of a general VCSEL and the power conversion efficiency.
Generally, the VCSEL has the maximum power conversion efficiency at an optical output of 4 mW to 8 mW. However, as compared with the case where the light output is used in a range smaller than that, the spread angle becomes large, and the light density on the irradiation surface does not increase in proportion to the increase in the light output.
Here, the VCSEL-A of the proximity detection light source 10 is preferably driven so as to be in the range of the light output in which the power conversion efficiency drops. That is, by intentionally emitting light with an optical output lower than the range in which the power conversion efficiency can be maximized, the light is emitted with a narrow spread angle. If the light density is insufficient on the irradiated surface, the light density can be increased while maintaining a narrow spread angle by increasing the number of VCSEL-A instead of increasing the light output per VCSEL-A. .. As an example, one optical output of the 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. In the configuration shown in FIG. 4, as described above, the proximity detection light source 10 includes a plurality of VCSEL-A in order to increase the light density while avoiding the range (4 mW to 8 mW) where the power conversion efficiency can be maximized. It is configured in.

On the other hand, the VCSEL-B of the 3D shape measurement light source 20 may be driven so as to have an optical output range in which the power conversion efficiency can be maximized. As an example, one optical output of the 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.

(Structure of diffuser plate 30)
Next, the diffuser plate 30 will be described.
FIG. 8 is a diagram illustrating an example of the configuration of the diffusion plate 30. 8 (a) is a plan view, and FIG. 8 (b) is a cross-sectional view taken along the line VIIIB-VIIIB of (a).
As shown in FIGS. 3A and 3B, the diffuser plate 30 is provided on the side where the proximity detection light source 10 and the 3D shape measurement light source 20 emit light, and the proximity detection light source 10 and the 3D shape are provided. The light emitted by each of the measurement light sources 20 is diffused. The diffuser plate 30 has a function of further expanding the spreading angle of the light incident on the diffuser plate 30.

As shown in FIG. 8A, the diffuser plate 30 includes a first region 30A and a second region 30B. 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. 3A, when the light emitting device 4 is viewed from the surface (viewed in a plan view), the first region 30A of the diffuser plate 30 is located at a position where the proximity detection light source 10 is arranged. The second region 30B of the diffuser plate 30 is provided so as to face each other, and is provided so as to face the light source 20 for 3D shape measurement. When the proximity detection light source 10 and the 3D shape measurement light source 20 are covered with a common diffuser plate 30, if the light from the proximity detection light source 10 is also diffused by the diffuser plate 30, proximity detection becomes difficult. Therefore, in order to use the common diffusion plate 30, the diffusion plate 30 includes a first region 30A and a second region 30B as described above. In the present embodiment, the proximity detection light source 10 and the 3D shape measurement light source 20 are arranged close to each other. This is because if the distance between the proximity detection light source 10 and the 3D shape measurement light source 20 is too large, an unnecessarily large diffuser plate is required when the common (integral) diffuser plate 30 is adopted. From the above, in the present embodiment, a small diffusion plate 30 in which the first region 30A and the second region 30B are integrated is adopted.

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. 8B, the diffuser plate 30 includes a resin layer 32 in which irregularities for diffusing light are formed on one surface of a flat glass substrate 31 whose both sides are parallel. However, the shape of the unevenness is different between the first region 30A and the second region 30B, and the diffusion angle is set to be larger in the second region 30B. The diffusion angle is the spread angle of the light transmitted through the diffusion plate 30.

Here, the first region 30A is not provided with irregularities and is configured so that light is not diffused. The resin layer 32 having irregularities in the second region 30B is flattened without providing irregularities in the first region 30A, or the surface of the flat glass base material 31 having both sides parallel to each other is exposed. Here, the first region 30A does not have 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 does not diffuse as in the case where the first region 30A is flat. As described above, 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. 8B, the VCSEL-A of the proximity detection light source 10 is arranged at a position facing the first region 30A of the diffusion plate 30. On the other hand, the VCSEL-B of the light source 20 for 3D shape measurement is arranged at a position facing the second region 30B of the diffuser plate 30. Let θ1 be the spread angle of the emitted light of the VCSEL-A, and θ2 be the spread angle of the emitted light of the VCSEL-B. Note that θ1 is smaller than θ2 (θ1 <θ2).

Then, when the light emitted from the VCSEL-A passes through the first region 30A having no unevenness, diffusion does not occur, and the spreading angle θ1 of the emitted light becomes the diffusion angle α and is transmitted as it is.
On the other hand, when the light emitted from the VCSEL-B passes through the second region 30B having irregularities, diffusion occurs and the light having a diffusion angle β larger than the spreading angle θ2 of the emitted light is emitted from the diffuser plate 30. Exit.
The spread angles θ1 and θ2 and the diffusion angles α and β are full width at half maximum (FWHM).

As described 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, an irradiation pattern having more uniformity can be obtained on a wider irradiation surface as compared with the case where the light emitted from the VCSEL-B is emitted to the outside without being diffused in the second region 30B. The second region 30B may be configured to have a uniform diffusion angle over the entire second region 30B, and the diffusion angle may be different depending on the position in the second region 30B. You may. Further, the second region 30B may be configured so that the optical axis of the VCSEL-B coincides with the central axis of the diffused light, and the center of the diffused light with respect to the optical axis of the VCSEL-B. The axis may be intentionally shifted so that the irradiation area is expanded.

The first region 30A may be provided with 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 spread angle includes not only the case where the incident light is condensed, but also the case where the incident light is made into parallel light or diffused but the degree of diffusion thereof is narrowed.

The size of the first region 30A may be determined in consideration of 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 recognition, when the proximity detection light source 10 is composed of, for example, a range of 1 to 50 VCSEL-A, the first region 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 in a plan view is circular, but it may be a square, a rectangle, a polygon, or a composite shape thereof. Further, the width and height 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, the range may be set larger than the half-value full width region of the light emitted from the proximity detection light source 10 and the range smaller than the 0.1% intensity region. Further, when it is desired to bring the VCSEL-A and the VCSEL-B closer to each other, the range may be set smaller than the region of 1% intensity or the range smaller than the region of 5% intensity.

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 length and 0.1 mm to 1 mm in thickness. The diffuser plate 30 may cover the proximity detection light source 10, the 3D shape measurement light source 20, and the light amount monitoring light receiving element 40 in a plan view. Further, although an example in which the shape of the diffusion plate 30 in a plan view is a quadrangular shape is shown, other shapes such as a polygonal shape and a circular shape may be used. With the above size and shape, a light diffusing member suitable for face recognition of a portable information processing terminal and measurement at a relatively short distance of up to several meters is provided.

(Position relationship between the diffuser plate 30, VCSEL-A of the proximity detection light source 10 and VCSEL-B of the 3D shape measurement light source 20)
FIG. 8B describes the positional relationship between the VCSEL-A of the proximity detection light source 10 and the VCSEL-B of the 3D shape measurement light source 20. Here, the spacing between the VCSEL-A of the proximity detection light source 10 and the VCSEL-B of the 3D shape measurement light source 20 adjacent to each other is p1, and the spacing between the VCSEL-A of the proximity detection light source 10 is p2, 3D. Let p3 be the interval between VCSEL-B of the shape measurement light source 20.

At this time, as can be seen from FIG. 8B, when the VCSEL-B is too close to the proximity detection light source 10, that is, when the interval p1 becomes small, the light having a high light intensity emitted from the VCSEL-B is emitted from the diffuser plate 30. It passes through the first region 30A and is easily emitted to the outside in a state where it is not diffused or diffused weakly. Therefore, it is preferable to provide a distance between the adjacent VCSEL-A and the VCSEL-B. For example, the VCSEL-B of the light source 20 for 3D shape measurement 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 should be done. By doing so, as compared with the case where the range of the spread angle θ2 of the emitted light of the 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 distance p1 between the VCSEL-A of the proximity detection light source 10 and the VCSEL-B of the 3D shape measurement light source 20 adjacent to each other is made larger than the distance p3 between the VCSEL-B of the 3D shape measurement light source 20. That is good.

Further, the spread angle θ1 of the emitted light of the VCSEL-A of the proximity detection light source 10 is set smaller than the spread angle θ2 of the emitted light of the VCSEL-B of the light source 20 for 3D shape measurement. However, the distance g1 is set from the light emission port 112A (see FIG. 5) of the VCSEL-A of the proximity detection light source 10 to the diffuser plate 30, and the light emission port 212A of the DCSEL-B of the 3D shape measurement light source 20 to the diffuser plate 30. When the distance g2 is set to, the distance g1 is smaller than the distance g2 (g1 <g2), that is, the light emission port 112A of the VCSEL-A of the proximity detection light source 10 is the VCSEL- of the light source 20 for 3D shape measurement. If the light emission port 212A of B is closer to the diffuser plate 30, as shown in FIG. 8B, the light emitted from the VCSEL-A of the proximity detection light source 10 is the first region 30A of the diffuser plate 30. Even when is small, the object to be measured is likely to be irradiated through the first region 30A.

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 smaller the amount of light emitted from the VCSEL-B of the 3D shape measurement light source 20 and passing through the first region 30A. Therefore, the 3D shape measurement light source 20 The VCSEL-B can be placed closer to the proximity detection light source 10. That is, the region (dead space) in which the VCSEL-B cannot be arranged, which is generated between the VCSEL-A of the proximity detection light source 10 adjacent to each other and the VCSEL-B of the 3D shape measurement light source 20, is reduced, and the diffuser 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 larger light output than the VCSEL-A of the proximity detection light source 10, the temperature tends to rise. Therefore, if the interval p3 between the VCSEL-B of the 3D shape measurement light source 20 is wider than the interval p2 between the VCSEL-A of the proximity detection light source 10 (p3> p2), the temperature rise is suppressed. On the other hand, since the VCSEL-A of the proximity detection light source 10 has a smaller light 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 the VCSEL-A of the proximity detection light source 10, is smaller than the distance p3, which is the distance between the VCSEL-B of the 3D shape measurement light source 20, the proximity detection light source 10 is occupied. It is easy to reduce the area.

Further, as shown in FIG. 8A, it is preferable that the first region 30A of the diffusion plate 30 is surrounded on all sides by the second region 30B. By doing so, 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. Is suppressed.

Next, a modified example of the diffusion plate 30 will be described.
FIG. 9 is a diagram showing a modified example of the diffusion plate 30. FIG. 9A is a first modification of the diffusion plate 30, and FIG. 9B is a second modification of the diffusion plate 30.
In the first modification of the diffusion plate 30 shown in FIG. 9A, the planar shape of the first region 30A of the diffusion plate 30 is formed into a slit shape extending in the + x direction. By doing so, 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. Is suppressed.

On the other hand, in the second modification of the diffusion plate 30 shown in FIG. 9B, the first region 30A of the diffusion plate 30 is provided at the right end portion (+ x direction side) of the diffusion plate 30. In this way, since the first region is not surrounded by the second region, the light emitted from the VCSEL-B of the light source 20 for 3D shape measurement is compared with the first modification of the diffuser plate 30. Among them, the amount of light passing through the first region 30A of the diffuser plate 30 increases. However, when the light 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 in a plan view is large. In the configuration on the premise that the light emitted from the VCSEL-B of the 3D shape measurement light source 20 is allowed to pass through the first region 30A, a 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 fact that the first region is surrounded by the second region means a state in which the second region 30B exists in at least two directions or more in a plan view.

(Configuration of 3D sensor 6)
FIG. 10 is a diagram illustrating the 3D sensor 6.
The 3D sensor 6 is configured by arranging a plurality of light receiving regions 61 in a matrix (lattice). The 3D sensor 6 receives a light receiving pulse which is reflected light from the object to be measured with respect to the light emitting pulse emitted from the light emitting device 4, and accumulates an electric charge corresponding to the time until the light is received in each light receiving region 61. As an example, the 3D sensor 6 is configured as a device having a CMOS structure in which each light receiving region 61 has two gates and a charge storage unit corresponding to them. Then, by alternately applying pulses to the two gates, the generated photoelectrons are transferred to one of the two charge storage units at high speed, and charges corresponding to the phase difference between the emitted light pulse and the received light pulse are accumulated. It is configured in. 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 region 61 is output as a signal via the AD converter. That is, the 3D sensor 6 is a signal corresponding to the time from the emission of light from the proximity detection light source 10 to the reception by the 3D sensor 6, and the 3D sensor after the light is emitted from the 3D shape measurement light source 20. A signal corresponding to the time until the light is received at 6 is output.

(Flowchart of authentication process in information processing device 1)
FIG. 11 is a flowchart for performing an authentication process relating to the use of the information processing device 1.
Here, the information processing device 1 has at least an off state in which the power is off, a standby state in which power is supplied only to a part of the information processing device 1, and a portion more than the standby state, for example, the information processing device. 1 It is assumed that the entire operation state in which power is supplied is provided.

First, it is determined whether or not there is a request for using the information processing device 1 (step 110. In FIG. 11, it is referred to as S110. The same applies to the others). The case where there is a usage request means a case where the power is turned on in the off state, a case where an operation is performed by the user to use the information processing device 1 in the standby state, and the like. It is also an example of a case where there is a usage request even when a telephone call, an e-mail, or the like arrives in the standby state. That is, the case where the system control unit 9 receives the signal for shifting to the operating state is applicable.
If a negative (NO) determination is made in step 110, that is, if the off state or the standby state continues, step 110 is repeated.

On the other hand, when a positive (YES) determination is made in step 110, that is, when the operation state is entered, light is emitted from the proximity detection light source 10 to the object to be measured, and the object to be measured is measured by the 3D sensor 6. The reflected light from the object is received (step 120). Regardless of whether or not there is a usage request in step 110, the proximity detection light source 10 may continue to irradiate light in the standby state.

Next, it is determined whether or not the objects to be measured are in close proximity (step 130). In addition, "close" means that the object to be measured is within a predetermined distance. If a negative (NO) determination is made in step 130, that is, if the objects to be measured are not in close proximity, the process returns to step 120.
On the other hand, when an affirmative (YES) determination is made in step 130, that is, when the object to be measured is in close proximity, light is emitted from the light source 20 for measuring the 3D shape, 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 irradiation of the light from the proximity detection light source 10 may be stopped, or the irradiation of the light 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 as compared with the case where the irradiation is not continued.

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

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

As described above, the information processing apparatus 1 in the present embodiment includes a proximity detection light source 10 and a 3D shape measurement light source 20. This determines whether or not the object to be measured is close to the information processing device 1 by irradiating light from the proximity detection light source 10, and when the object to be measured is close to the information processing device 1, the light source 20 for 3D shape measurement. Is irradiated with light for 3D measurement. That is, the light source 20 for measuring the 3D shape is suppressed from emitting light even though the objects to be measured are not close to each other. Further, at this time, the power consumption is suppressed by making the light output of the proximity detection light source 10 smaller than the light output of the 3D shape measurement light source 20. That is, when the information processing device 1 is a portable information processing terminal, the decrease in the charge amount 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 and the 3D shape measurement light source 20 and the conductor pattern provided on the circuit board 7 will be described with reference to FIG.
Cathode patterns 71 for the proximity detection light source 10, anode patterns 72, cathode patterns 73 for the 3D shape measurement light source 20, and anode patterns 74A and 74B are provided on the circuit board 7 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). The anode electrode 118 includes a pad portion 118A to which the p-side electrodes 112 of the four VCSEL-A are connected and to which the bonding wire 76 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). The anode electrode 218 is formed so as to connect the anode electrodes 218 of the VCSEL-B arranged in a matrix, and is extended in the ± y direction to connect the bonding wires 75A and 75B described later. It includes parts 218A and 218B.

The cathode pattern 71 for the proximity detection light source 10 is formed in a larger area than the proximity detection light source 10 so that the cathode electrodes 114 provided on the back surface of the proximity detection light source 10 are connected. In the proximity detection light source 10, the cathode electrode 114 provided on the back surface and the cathode pattern 71 for the proximity detection light source 10 on the circuit board 7 are adhered 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 by the bonding wire 76.

Similarly, the cathode pattern 73 for the 3D shape measurement light source 20 is formed in a larger 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. Then, the light source 20 for 3D shape measurement is adhered on the cathode pattern 73 for the light source 20 for 3D shape measurement with a conductive adhesive or the like.
The anode patterns 74A and 74B for the 3D shape measurement light source 20 face each other (± y direction side) of the anode electrodes 218 (see FIG. 6) provided on the surface of the 3D shape measurement light source 20. It is provided in. The anode patterns 74A and 74B and the pad portions 218A and 218B of the anode electrodes 218 of the 3D shape measurement light source 20 are connected by bonding wires 75A and 75B, respectively. A plurality of bonding wires 75A and 75B are provided, and one of them is designated by 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 a higher speed, both may be driven on the low side. The low-side drive refers to a configuration in which a drive unit such as a MOS transistor is located on the downstream side of a current path with respect to a drive target such as a VCSEL. Conversely, a configuration in which the drive unit is located on the upstream side is called high-side drive. In the present embodiment, in order to drive both the proximity detection light source 10 and the 3D shape measurement light source 20 on the low side, the cathodes of both 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 unit 50A, the second drive unit 50B, and the optical device control unit 8. Is shown. The first drive unit 50A and the second drive unit 50B are grounded via a MOS transistor. That is, the VCSEL is driven on the low side by turning the MOS transistor on / off.
In FIG. 12, the anode side of 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.

(Arrangement of proximity detection light source 10, 3D shape measurement light source 20 and light amount monitoring light receiving element 40 in the light emitting device 4)
FIG. 13 is a diagram for explaining the arrangement of the proximity detection light source 10, the 3D shape measurement light source 20, and the light amount monitoring light receiving element 40 in the light emitting device 4. 13 (a) is an arrangement described as the present embodiment, FIG. 13 (b) is a first modified example of the arrangement, and FIG. 13 (c) is a second modified example of the arrangement. (D) is a third modification of the arrangement. Here, the proximity detection light source 10, the 3D shape measurement light source 20, the light amount monitoring light receiving element 40, and the bonding wire are shown, and other descriptions are omitted. The side surface in the −x direction is the side surface 21A, the side surface in the + x direction is the side surface 21B, the side surface in the + y direction is the side surface 21C, and the side surface in the −y direction is the side surface 21D in the 3D shape measurement light source 20 having a quadrangular planar shape. .. Here, the side surface 21A and the side surface 21B face each other, and the side surface 21C and the side surface 21D face each other by connecting the side surface 21A and the side surface 21B.

In the arrangement described as the present embodiment shown in FIG. 13 (a) (see FIG. 3 (a)), the light quantity monitoring light receiving element 40 is provided on the side surface 21A side of the 3D shape measurement light source 20 in the −x direction. ing. The proximity detection light source 10 is provided on the side surface 21B side of the 3D shape measurement light source 20 in the + x direction. The bonding wires 75A and 75B connecting the anode electrodes 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 light sources for 3D shape measurement. It is provided so as to face the side surfaces 21C and 21D of 20 in the ± y direction.

By doing so, the 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, as compared with the third comparative example shown in FIG. 13D, which will be described later, the current is likely to be more evenly supplied to each VCSEL-B of the 3D shape measurement light source 20.

A bonding wire is not provided on the side surface 21A side in the −x direction of the 3D shape measurement light source 20 in which the light intensity monitoring light receiving element 40 is arranged. Therefore, it is easy to arrange the light receiving element 40 for monitoring the amount of light close to the light source 20 for measuring the 3D shape. Therefore, the light quantity monitoring light receiving element 40 is the light reflected on the diffuser plate 30 among the emitted light from the 3D shape measurement light source 20 as compared with the second comparative example shown in FIG. 13 (c) described later. Is easy to receive.

In the first modification of the arrangement shown in FIG. 13B, the light quantity monitoring light receiving element 40 is arranged on the side surface 21B side 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 light source 20 for measuring the 3D shape and the light receiving element 40 for monitoring the amount of light is farther than the arrangement in the present embodiment shown in FIG. 13A. Therefore, among the light emitted from the 3D shape measurement light source 20, the amount of light received by the diffuser plate 30 is reduced. That is, it is difficult to receive the light reflected by the diffuser plate 30. Therefore, the detection accuracy may decrease.

In the second modification of the arrangement shown in FIG. 13C, the light quantity monitoring light receiving element 40 is on the side surface 21B side of the 3D shape measurement light source 20 in the + x direction, and is close to the 3D shape measurement light source 20. It is arranged between the light source 10 and the light source 10. Therefore, it is easy to arrange the light receiving element 40 for monitoring the amount of light close to the light source 20 for measuring the 3D shape. Therefore, as in FIG. 13A described above, the current can be more evenly supplied to each VCSEL-B of the 3D shape measurement light source 20, and the light quantity monitoring light receiving element 40 is for 3D shape measurement. Of the light emitted from the light source 20, the light reflected on 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, an anode pattern is separately provided on the circuit board 7 on the side surface 21A side in the −x direction of the 3D shape measurement light source 20, and is separately provided on the anode electrode 218 of the 3D shape measurement light source 20 and the circuit board 7. A bonding wire 75C for connecting to the anode pattern is provided. A plurality of bonding wires 75C are provided, and one of them is designated by a reference numeral.

The proximity detection light source 10 is provided on the side surface 21D side of the 3D shape measurement light source 20 in the −y direction, and the light quantity monitoring light receiving element 40 is provided on the side surface 21B side of the 3D shape measurement light source 20 in the + x direction. There is. In this way, the light source 20 for measuring the 3D shape 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 of the 3D shape measurement light source 20. It is difficult to apply current uniformly to −B. Therefore, the third modification is preferably used in specifications that have little effect even if the current is difficult to 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. Further, in the light emitting device 4, at least the proximity detection light source 10, the 3D shape measurement light source 20, the diffuser plate 30, and the spacer 33 are provided on a substrate different from the circuit board 7, and these are provided as one light emitting component (module). ) May be configured to be connectable to a circuit board 7 on which the first drive unit 50A, the second drive unit 50B, the 3D sensor 6 and the like are mounted. As an example, the diffuser plate 30, the spacer 33, and the substrate covering the proximity detection light source 10 and the 3D shape measurement light source 20 may define the maximum outer shape of the light emitting component. With such a configuration, since the first drive unit 50A, the second drive unit 50B, the 3D sensor 6, and the like are not mounted on the light emitting component, they are provided and distributed as small components. Further, since the proximity detection light source 10 and the 3D shape measurement light source 20 are sealed by being surrounded by the diffuser plate 30, the spacer 33, and the substrate, dustproof, moisture-proof, etc. are compared with the case where they are not sealed. Can be taken. The light emitting component may or may not include the light intensity monitoring light receiving element 40.

Further, the proximity detection light source 10 in the above configuration does not necessarily have to be used in combination with the 3D shape measurement light source 20. For example, the proximity detection light source 10 may be provided alone as a light source for distance measurement regardless of whether or not the 3D shape is measured. That is, it may be provided as a single vertical resonance type surface emitting laser element array having a plurality of long resonator structures connected in parallel with 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 is driven in the range where the power conversion efficiency can be maximized. Compared with the case, the light density is increased while suppressing the increase in the spread angle. Therefore, in particular, in a configuration in which the visual field range of the light receiving unit is narrow and a range wider than the visual field range of the light receiving unit on the irradiation surface is irradiated, light reception with a higher SN ratio is performed.

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

1 ... Information processing device, 2 ... User interface (UI) unit, 3 ... Optical device, 4 ... Light source device, 6 ... 3D sensor, 7 ... Circuit board, 8 ... Optical device control unit, 9 ... System control unit, 10 ... Proximity detection light source, 20 ... 3D shape measurement light source, 30 ... diffuser plate, 30A ... first region, 30B ... second region, 33 ... spacer, 40 ... light quantity monitoring light receiving element, 50A ... first drive Unit, 50B ... Second drive unit, 61 ... Light receiving area, 81 ... Shape identification unit, 91 ... Authentication processing unit, VCSEL, VCSEL-A, VCSEL-B ... Vertical resonator surface light emitting laser element

Claims (10)

The first light source that oscillates in single transverse mode,
A second light source that oscillates in multiple transverse mode, which has a higher light output than the first light source and is configured to be driven independently of the first light source.
A light diffusing member provided on the emission path of the second light source and
A light emitting device equipped with. The first light source includes at least one or more first vertical resonator surface emitting laser elements, and the second light source includes a plurality of second vertical resonator surface emitting laser elements.
A claim that the light output emitted from one of the first vertical resonator surface emitting laser elements is driven to be smaller than the light output emitted from one of the second vertical resonator surface emitting laser elements. Item 2. The light emitting device according to item 1. The first light source includes at least one or more first vertical resonator surface emitting laser elements, and the second light source includes a plurality of second vertical resonator surface emitting laser elements.
The light emitting device according to claim 1, wherein the light emitting device is driven by an optical output in which the power conversion efficiency of the first vertical resonator surface emitting laser element is lower than the power conversion efficiency of the second vertical resonator surface emitting laser element. The second or third aspect of claim 2 or 3, wherein the first vertical resonator surface emitting laser element is driven so that the light output of one of the first vertical resonator surface emitting laser elements is in the range of 1 mW to 4 mW. Light emitting device. The second vertical resonator surface emitting laser element is any of claims 2 to 4 in which the light output of one of the second vertical resonator surface emitting laser elements is driven so as to be in the range of 4 mW to 8 mW. The light emitting device according to item 1. The first vertical resonator surface emitting laser element has a long resonator structure having a resonator length of 5λ to 20λ, where λ is the oscillation wavelength, according to any one of claims 2 to 5. Light emitting device. The light emitting device according to any one of claims 1 to 6.
The first reflected light emitted from the first light source included in the light emitting device and reflected by the object to be measured, and the second reflected light emitted from the second light source included in the light emitting device and reflected by the object to be measured. It is equipped with a light receiving unit that receives light.
The light receiving unit receives a signal corresponding to the time from the time when light is emitted from the first light source to the time when the light is received by the light receiving unit, and the light received by the light receiving unit after the light is emitted from the second light source. An optical device that outputs a signal corresponding to the time until it is processed. The light emitting device according to any one of claims 1 to 6.
The first reflected light emitted from the first light source included in the light emitting device and reflected by the object to be measured, and the second reflected light emitted from the second light source included in the light emitting device and reflected by the object to be measured. It is equipped with a light receiving unit that receives light.
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 exists within a predetermined distance. The optical device according to claim 7 or 8.
A shape specifying unit that specifies the three-dimensional shape of the object to be measured based on the second reflected light emitted from the second light source included in the optical device and reflected by the object to be measured.
Information processing device equipped with. An authentication processing unit that performs authentication processing related to the use of the own device based on the specific result of the shape specifying unit, and
9. The information processing device according to claim 9.