Light emitting device and distance measuring device

Abstract

A light-emitting device includes: a light-emitting unit having a first light source that irradiates a first irradiation range and a second light source that irradiates a second irradiation range in a lighted state, the light-emitting unit irradiating the first irradiation range and the second irradiation range in parallel or in an overlapping manner over a reference distance; and a driving unit that drives the light emitting unit so that one of the first light source and the second light source is turned on and the other is turned off when an object having a first distance different from the reference distance is irradiated by the light emitting unit.

Description

Technical Field

[0001] The present invention relates to a light-emitting device and a distance measuring device. Background Art

[0002] Patent Document 1 describes a distance measuring device including: a light source having a two-dimensionally arranged light-emitting region; and a light receiving unit that receives reflected light reflected by a distance measurement target present in a distance measurement region. In this device, pre-illumination is performed by simultaneously illuminating each light-emitting point of the light source with the same light amount, and the light emission amount of the main illumination is controlled based on the light reception amount of each light reception region measured by a regional light amount measurement unit through the pre-illumination.

[0003] Patent Document 2 describes a detection device including: a light source device that divides an irradiation region of light from a plurality of light-emitting units to a detection target into a plurality of irradiation regions and irradiates the detection target; a light source drive unit that switches a plurality of illuminance levels for each of the plurality of irradiation regions; and a control unit that switches a plurality of illuminance levels for each of the plurality of irradiation regions and accumulates / combines a plurality of detection data related to the detected detection target.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-160044

[0005] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2021-071478 Summary of the Invention

[0006] There is a distance measuring device that measures the distance to an object by the so-called time-of-flight (TOF: Time Of Flight) method, which measures the time from when light is emitted from a light-emitting unit until the light reflected by the object is received by a light receiving unit (sometimes referred to as "distance measurement"). In such a distance measuring device and the like, there is a method of designing a light-emitting unit such that when a plurality of light sources are lit, a region formed by juxtaposing or overlapping the irradiation ranges of the respective light sources can be irradiated. In this method, depending on the distance to the object, the deviation of the irradiation ranges of the respective light sources becomes larger, which may affect the distance measurement.

[0007] An object of the present invention is to suppress the influence caused by the deviation of the irradiation ranges of the respective light sources as compared with the case where all light sources are lit regardless of the distance.

[0008] The invention according to Scheme 1 is a light-emitting device, characterized by including: a light-emitting unit having a first light source that irradiates a first irradiation range and a second light source that irradiates a second irradiation range in a lit state, and juxtaposing or overlapping the first irradiation range and the second irradiation range at a reference distance; and a drive unit that drives the light-emitting unit such that when irradiating an object at a first distance different from the reference distance, one of the first light source and the second light source is in a lit state and the other is in an extinguished state.

[0009] The invention according to Embodiment 2 is the light-emitting device according to Embodiment 1, characterized in that the first light source includes a plurality of light-emitting sections that respectively emit light toward a plurality of irradiation sections obtained by dividing the first irradiation range, the second light source includes a plurality of light-emitting sections that respectively emit light toward a plurality of irradiation sections obtained by dividing the second irradiation range, and the driving unit drives the light-emitting sections in the first light source and the second light source respectively so that the light-emitting sections that emit light toward adjacent irradiation sections emit light at different times.

[0010] The invention according to Embodiment 3 is the light-emitting device according to Embodiment 2, characterized in that the first light source has a first light-emitting section that irradiates a first irradiation section and a third light-emitting section that irradiates a third irradiation section adjacent to the first irradiation section, the second light source has a second light-emitting section that irradiates a second irradiation section and a fourth light-emitting section that irradiates a fourth irradiation section adjacent to the second irradiation section, at the reference distance, the first irradiation section and the second irradiation section overlap, and the third irradiation section and the fourth irradiation section overlap, and the driving unit drives the light-emitting sections at the first distance where the first irradiation section and the fourth irradiation section overlap so that one of them is in the lit state and the other is in the extinguished state.

[0011] The invention according to Embodiment 4 is the light-emitting device according to any one of Embodiments 1 to 3, characterized in that based on the lighting history of the first light source and the second light source, it is set which one is in the lit state and which one is in the extinguished state.

[0012] The invention according to Embodiment 5 is the light-emitting device according to Embodiment 4, characterized in that when irradiating an object at the first distance, the driving unit drives the light-emitting sections so that the one with a shorter total lighting time in the first light source and the second light source is in the lit state and the other with a longer total lighting time is in the extinguished state.

[0013] The invention according to Embodiment 6 is the light-emitting device according to Embodiment 4, characterized in that the first light source and the second light source respectively have a plurality of light-emitting sections that emit light toward the first irradiation range and the second irradiation range, and are driven so that each group including at least one light-emitting section emits light at different times. When irradiating an object at the first distance, the driving unit drives the light-emitting sections so that the one with less influence on the light emission of the next group by the heat generated by the light emission of the previous group is in the lit state and the other with greater influence is in the extinguished state.

[0014] The invention according to Embodiment 7 is the light-emitting device according to any one of Embodiments 1 to 6, characterized in that when an object is detected at the first distance, the driving unit drives the light-emitting unit in such a manner that one of the first light source and the second light source is in a lit state and the other is in an extinguished state.

[0015] The invention according to Embodiment 8 is the light-emitting device according to any one of Embodiments 1 to 7, characterized in that the first irradiation range and the second irradiation range overlap at the reference distance, and the first distance is closer than the reference distance.

[0016] The invention according to Embodiment 9 is a light-emitting device, characterized by comprising: a light-emitting unit having a first light source that irradiates a first irradiation range and a second light source that irradiates a second irradiation range in a lit state, and irradiating the first irradiation range and the second irradiation range side by side or overlapping at a reference distance; and a driving unit capable of switching between a first mode for irradiating an object at a first distance different from the reference distance and a second mode for irradiating an object at a distance farther than the first distance through the light-emitting unit to drive the light-emitting unit. In the first mode, the driving unit drives the light-emitting unit in such a manner that one of the first light source and the second light source is in a lit state and the other is in an extinguished state, and in the second mode, the driving unit drives the light-emitting unit in such a manner that both the first light source and the second light source are in a lit state.

[0017] The invention according to Embodiment 10 is the light-emitting device according to Embodiment 9, characterized in that when it is predicted that an object will reach the first distance, the driving unit drives the light-emitting unit through the first mode.

[0018] The invention according to Embodiment 11 is a distance measuring device, characterized by comprising: the light-emitting device according to any one of Embodiments 1 to 10; a light-receiving unit that receives light irradiated from the light-emitting device and reflected by an object; and a calculation unit that calculates the distance to the object based on the light-receiving result in the light-receiving unit.

[0019] The invention according to Embodiment 12 is the distance measuring device according to Embodiment 11, characterized in that when an object is detected at the first distance or it is predicted that an object will reach the first distance based on the light-receiving result in the light-receiving unit or the calculation result in the calculation unit, the driving unit drives the light-emitting unit in such a manner that one of the first light source and the second light source is in a lit state and the other is in an extinguished state.

[0020] Advantageous Effects of the Invention

[0021] According to the first aspect of the present invention, compared with the case where all light sources are lit regardless of the distance, it is possible to suppress the influence caused by the deviation of the irradiation range of each light source.

[0022] According to the second aspect of the present invention, compared with the case where all light sources are lit regardless of the distance, interference with adjacent irradiation sections can be suppressed.

[0023] According to the third aspect of the present invention, even under conditions where interference is likely to occur due to overlap of irradiation ranges with each other, interference with adjacent irradiation sections can be suppressed.

[0024] According to the fourth aspect of the present invention, compared with the case where light sources are fixed in the lit state and the extinguished state, drive control corresponding to the lighting conditions of each light source can be performed.

[0025] According to the fifth aspect of the present invention, compared with the case where light sources are fixed in the lit state and the extinguished state, deviation in the total lighting time of each light source is suppressed.

[0026] According to the sixth aspect of the present invention, compared with the case where light sources are fixed in the lit state and the extinguished state, the influence of heat generated by light emission on luminous efficiency is suppressed.

[0027] According to the seventh aspect of the present invention, irradiation of an object existing at the first distance is suppressed in a state where the irradiation ranges of the respective light sources are shifted.

[0028] According to the eighth aspect of the present invention, in the vicinity of the light emitting unit where the amount of light irradiated is larger than on the side farther from the light emitting unit, the amount of light irradiated in the overlapping portion and the non-overlapping portion becomes uneven, and the amount of light irradiated onto the object is suppressed from becoming excessive.

[0029] According to the ninth aspect of the present invention, compared with the case where all light sources are lit regardless of the distance, the influence caused by the shift of the irradiation ranges of the respective light sources is suppressed.

[0030] According to the tenth aspect of the present invention, irradiation of an object that has reached the first distance is suppressed in a state where the irradiation ranges of the respective light sources are shifted.

[0031] According to the eleventh aspect of the present invention, compared with the case where all light sources are lit regardless of the distance, the influence caused by the shift of the irradiation ranges of the respective light sources can be suppressed.

[0032] According to the twelfth aspect of the present invention, detection of an object can be performed without setting a separate sensor, and it can be used for control. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The embodiments of the present invention will be described in detail with reference to the following drawings.

[0034] Figure 1 is a block diagram showing an example of the schematic configuration of a distance measuring device to which this embodiment is applied;

[0035] Figure 2 It is a diagram showing the light source included in the light-emitting unit of the present embodiment and the irradiation range, i.e., the irradiation range, of the light emitted from the light source;

[0036] Figure 3 It is a diagram showing the light source included in the light-emitting unit of the present embodiment and the irradiation surface irradiated with the light emitted from the light source;

[0037] Figure 4 Among them, Figure 4 (a) of Figure 4 (b) of is a diagram showing the light source and the irradiation surface when one of the light sources is in the lit state and the other is in the extinguished state;

[0038] Figure 5 It is a diagram showing the light source included in the light-emitting unit of Embodiment 2 and the irradiation surface irradiated with the light emitted from the light source;

[0039] Figure 6 Among them, Figure 6 (a) of Figure 6 (b) of is a diagram showing the range of the light emitted from the light source, i.e., the irradiation range;

[0040] Figure 7 It is a diagram for explaining an example of the structure of the light-receiving unit to which Embodiment 2 is applied, and is a diagram showing the light-receiving surface of the light-receiving unit and the above-mentioned irradiation surface;

[0041] Figure 8 Among them, Figure 8 (a) of Figure 8 (b) of is a diagram showing an example of the state of the irradiation surface when the light source is driven in such a manner that light is irradiated to adjacent partitions at different times;

[0042] Figure 9 Among them, Figure 9 (a) of Figure 9 (b) of is a diagram for explaining the irradiation range of the light source on the irradiation surface at a distance closer than the reference distance in the +z direction from the light-emitting unit;

[0043] Figure 10 Among them, Figure 10 (a) of Figure 10 (b) of is a diagram for explaining the overlap of the irradiation ranges based on the light source on the irradiation surface;

[0044] Figure 11 It is a diagram for explaining an example of the drive control of the light-emitting unit by the light-emitting drive unit at the third time;

[0045] Figure 12 Among them, Figure 12 (a) of Figure 12Figure (c) is a diagram for explaining the structure of the light source included in the light-emitting unit of Embodiment 3;

[0046] Figure 13 is a diagram showing the light source included in the light-emitting unit of Embodiment 3 and the irradiation surface irradiated with the light emitted from the light source;

[0047] Figure 14 is a diagram showing the light source included in the light-emitting unit of Embodiment 4 and the irradiation range, which is the range irradiated with the light emitted from the light source;

[0048] Figure 15 is a diagram for explaining the structure of the light source included in the light-emitting unit of Embodiment 4;

[0049] Figure 16 In Figure 16 (a) to Figure 16 (b) are diagrams for explaining the irradiation surface.

[0050] Reference Signs

[0051] 1 - distance measuring device, 3 - optical device, 4 - light-emitting unit, 4A, 4B, 4C, 4D, 4E, 4F, 4G - light sources, 5 - light-receiving unit, 6 - light-emitting drive unit, 7 - light-receiving drive unit, 8 - control unit, 100A, 100B, 100C, 100D, 100E, 100F, 100G - irradiation ranges. Detailed Embodiments

[0052] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0053] In addition, the technical scope of the present invention is not limited to the scope described as the embodiments below. It is clearly understood from the description of the scope of the technical solution that cases where multiple embodiments are combined and cases where various changes or improvements are made to these embodiments are also included in the technical scope of the present invention.

[0054] [Embodiment 1]

[0055] (Distance Measuring Device 1)

[0056] Figure 1 is a block diagram showing an example of the schematic structure of the distance measuring device 1 to which this embodiment is applied.

[0057] The distance measuring device 1 measures the distance to the object based on the time from the moment when the light is emitted from the light emitting unit 4 to the moment when the light reflected by the object is received by the light receiving unit 5. That is, the distance measuring device 1 is a device that performs distance measurement according to the ToF method. In the ToF method, there are: an indirect ToF (iToF: indirect ToF) method that measures the time based on the difference in the phase of the emitted light and the phase of the received light; and a direct ToF (dToF: direct ToF) method that directly measures the time from the emission of light to the reception of light. These methods can all be applied, but in this embodiment, it is described that the distance measuring device 1 performs distance measurement according to the indirect ToF method.

[0058] As Figure 1 shown, the distance measuring device 1 includes an optical device 3 and a control unit 8.

[0059] The optical device 3 includes: a light emitting unit 4 that irradiates light toward a preset range; a light receiving unit 5 that receives the light reflected by the object existing within the range where the light is irradiated from the light emitting unit 4; a light emission driving unit 6 that drives the light emitting unit 4; and a light reception driving unit 7 that drives the light receiving unit 5. The light emitting unit 4 is an example of a light emitting device. The light emission driving unit 6 is an example of a driving unit.

[0060] (Control unit 8)

[0061] The control unit 8 controls the operations of the light emitting unit 4 and the light receiving unit 5 of the optical device 3.

[0062] Furthermore, the control unit 8 obtains the light reception result in the light receiving unit 5, and based on this light reception result, measures the distance from the distance measuring device 1 to the object by the ToF method.

[0063] The control unit 8 is an example of a calculation unit.

[0064] The control unit 8 is composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory).

[0065] The CPU 81 is an example of a processor, and realizes the various functions described later by loading various programs stored in the ROM 82, etc. into the RAM 83 and executing them. The RAM 83 is a memory used as a working memory for the CPU 81, etc. The ROM 82 is a memory that stores various programs executed by the CPU 81, etc.

[0066] Here, the program executed by the CPU 81 can be provided in a state stored in a computer-readable recording medium such as a magnetic recording medium (magnetic tape, magnetic disk, etc.), an optical recording medium (optical disk, etc.), a magneto-optical recording medium, or a semiconductor memory. Also, the program executed by the CPU 81 can be provided using a communication unit such as the Internet.

[0067] Also, in the present embodiment, the processor refers to a processor in a broad sense and includes a general-purpose processor (e.g., CPU: Central Processing Unit, etc.) and a dedicated processor (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0068] Also, the operation of the processor in the present embodiment can be completed not only by one processor but also by multiple processors located at physically separate positions collaborating. Also, the order of each operation of the processor is not limited to the order described in the present embodiment and can be changed.

[0069] (Light-emitting unit 4)

[0070] Figure 2 is a diagram showing the light sources 4A and 4B included in the light-emitting unit 4 of the present embodiment and the irradiation ranges 100A and 100B, which are the ranges irradiated by the light emitted from the light sources 4A and 4B. Also, in the present embodiment, an example in which the light-emitting unit 4 has two light sources is shown, but the number of light sources included in the light-emitting unit 4 can be three or more. As an example of a mode in which the light-emitting unit 4 has three or more light sources, Embodiment 3 is shown later.

[0071] In Figure 2 , the front side of the paper surface is set as the +x direction, the upper direction of the paper surface is set as the +y direction, the right direction of the paper surface is set as the +z direction, and the opposite directions are set as the -x, -y, and -z directions.

[0072] The light-emitting unit 4 has a light source 4A that irradiates light to the irradiation range 100A and a light source 4B that irradiates light to an irradiation range 100B different from the irradiation range 100A. The light-emitting unit 4 irradiates the irradiation range 100A based on the light source 4A and the irradiation range 100B based on the light source 4B side by side or overlapping. In this example, the light source 4A is an example of the first light source, the light source 4B is an example of the second light source, the irradiation range 100A is an example of the first irradiation range, and the irradiation range 100B is an example of the second irradiation range.

[0073] In the light-emitting unit 4 of the present embodiment, the light sources 4A and 4B are arranged side by side in the y direction. In this example, the light source 4A is arranged on the +y direction side with respect to the light source 4B.

[0074] Here, the irradiation range 100A refers to the range irradiated by the light emitted from the light source 4A at a certain distance in the +z direction from the light-emitting unit 4. Similarly, the irradiation range 100B refers to the range irradiated by the light emitted from the light source 4B at a certain distance in the +z direction from the light-emitting unit 4.

[0075] The irradiation range 100A and the irradiation range 100B are shown side by side, indicating that at a certain distance in the +z direction from the light-emitting unit 4, the irradiation range 100A and the irradiation range 100B are arranged in a direction intersecting the z direction. And the overlap of the irradiation range 100A and the irradiation range 100B means that at a certain distance in the +z direction from the light-emitting unit 4, at least a part of the region of the irradiation range 100A overlaps with at least a part of the region of the irradiation range 100B. In Figure 2 the overlapping part of the irradiation range 100A and the irradiation range 100B is represented by hatched lines.

[0076] In addition, in the present embodiment, the distance in the +z direction from the light-emitting unit 4 more accurately represents the distance from the light-emitting surface 41 (described later) of the light source 4A in the light-emitting unit 4 and the light-emitting surface 42 (described later) of the light source 4B.

[0077] And, in Figure 2 the irradiation surfaces 210 and 220 irradiated by the light of the irradiation range 100A and the irradiation range 100B are shown at a certain distance in the direction (+z direction) in which the light sources 4A and 4B emit light and are orthogonal to the +z direction. The irradiation surfaces 210 and 220 spread in the x direction and the y direction at a certain distance in the +z direction. And the irradiation surfaces 210 and 220 are arranged in sequence in the +z direction from the light sources 4A and 4B. Hereinafter, the distance in the +z direction from the light sources 4A and 4B to the irradiation surface 210 is denoted as the distance L1, and the distance in the +z direction from the light sources 4A and 4B to the irradiation surface 220 is denoted as the distance L2.

[0078] In addition, the relationship between the irradiation range 100A and the irradiation range 100B on the irradiation surfaces 210 and 220 will be described in detail later.

[0079] The light sources 4A and 4B have light-emitting surfaces on which a plurality of vertical cavity surface emitting lasers VCSEL (Vertical Cavity Surface Emitting Laser) are arranged. Hereinafter, the light-emitting surface of the light source 4A is denoted as the light-emitting surface 41 (refer to the following Figure 3), the light emitting surface of the light source 4B is marked as the light emitting surface 42 (refer to Figure 3 ).

[0080] The light rays emitted from the light sources 4A and 4B are diffused by a diffusion part (not shown) provided in the light sources 4A and 4B toward a plane perpendicular to the emission direction and are irradiated. As the diffusion part, a diffusion plate that is provided on the optical path of light and diffuses light by scattering or the like, a diffractive optical element (DOE: Diffractive Optical Element) that changes the angle of incident light and emits it, or / and an optical component such as a lens can be used.

[0081] The irradiation range 100A based on the light source 4A and the irradiation range 100B based on the light source 4B are diffused in the ±x direction and the ±y direction as they face the +z direction.

[0082] In the present embodiment, as Figure 2 shown, in a region where the distance in the +z direction from the light sources 4A and 4B is less than the distance L2, the irradiation range 100A is located on the +y direction side compared to the irradiation range 100B. And, in the present embodiment, as the distance from the light sources 4A and 4B becomes farther, the ratio of the overlapping part of the irradiation range 100A and the irradiation range 100B in the range where the irradiation ranges 100A and 100B are combined becomes larger.

[0083] In the light emitting part 4 of the present embodiment, the light sources 4A and 4B are independently driven by a light emission driving part 6 (refer to Figure 1 ) to perform a light emission operation. Incidentally, the light sources 4A and 4B emit light by supplying power to the VCSELs included in the light sources 4A and 4B using the light emission driving part 6.

[0084] In addition, the amount of light emitted from the VCSELs included in the light sources 4A and 4B changes according to the magnitude of the current value flowing through the VCSELs when power is supplied. That is, in the light sources 4A and 4B, the greater the power supplied and the greater the current value flowing through the VCSELs, the more light is emitted from the VCSELs. In addition, in the following description, the current values of the VCSELs constituting the light sources 4A and 4B may sometimes be simply referred to as the current values of the light sources 4A and 4B.

[0085] Here, "independently driven" means that each of the light sources 4A and 4B is driven to be in a light emitting state. The light emission driving part 6 is based on a signal from the control part 8 (refer to Figure 1) The control signals drive the light sources 4A and 4B. Therefore, the light sources 4A and 4B do not necessarily emit light simultaneously. For example, a state where the light source 4A emits light but the light source 4B does not emit light can be adopted. In the present embodiment, the state where the light sources 4A and 4B are emitting light is sometimes referred to as the light sources 4A and 4B being in the lit state, and the state where the light sources 4A and 4B are not emitting light is referred to as the light sources 4A and 4B being in the extinguished state. The switching of the light sources 4A and 4B between the lit state and the extinguished state will be described in detail later.

[0086] Figure 3 FIG. is a diagram showing the light sources 4A and 4B included in the light emitting unit 4 of the present embodiment and the irradiation surfaces 210 and 220 irradiated with the light emitted from the light sources 4A and 4B. In Figure 3 FIG., the right direction of the paper surface is set as the +x direction, the upper direction of the paper surface is set as the +y direction, the back side of the paper surface is set as the +z direction, and the opposite directions are set as the -x, -y, and -z directions. Additionally, in Figure 3 FIG., the light emitting unit 4 and the irradiation surfaces 210 and 220 are shown shifted in the vertical direction (±y direction) of the paper surface, but actually, the light emitting unit 4 and the irradiation surfaces 210 and 220 are arranged opposite to each other. In Figure 3 FIG., the light emitting unit 4 is located in the front side direction (-z direction) of the paper surface, and the irradiation surface 210 and the irradiation surface 220 are sequentially located in the back side direction (+z direction) of the paper surface. That is, Figure 3 FIG. is a view of the light emitting unit 4 emitting light as observed from the side opposite to the side from which the light is emitted from the light emitting unit 4.

[0087] In Figure 3 FIG., on the irradiation surfaces 210 and 220, the overlapping portion of the irradiation range 100A based on the light source 4A and the irradiation range 100B based on the light source 4B is indicated by hatching.

[0088] As Figure 3 shown, the light emitting surfaces 41 of the light source 4A and the light emitting surface 42 of the light source 4B of the light emitting unit 4 are arranged side by side in the y direction. In this example, the light emitting surface 41 of the light source 4A is arranged side by side with respect to the light emitting surface 42 of the light source 4B on the +y direction side.

[0089] Moreover, when observing the shapes of the light emitting surface 41 and the light emitting surface 42 in the z direction, they are rectangular shapes having sides extending in the x direction and the y direction. Incidentally, in the present embodiment, the shapes and areas of the light emitting surface 41 and the light emitting surface 42 as observed in the +z direction are equal to each other.

[0090] As described above, the light emitting unit 4 of the present embodiment diffuses and irradiates the light emitted from the light sources 4A and 4B onto a surface perpendicular to the emission direction. Therefore, the areas of the irradiation surfaces 210 and 220 increase in the order of the irradiation surface 210 and the irradiation surface 220 arranged in the +z direction.

[0091] Furthermore, the shapes of the irradiation range 100A and the irradiation range 100B on the irradiation surfaces 210 and 220 are substantially rectangular in accordance with the shapes of the light emitting surfaces 41 and 42 .

[0092] The light emitting unit 4 of this embodiment irradiates light on the irradiation surface 220 at a distance L2 in the +z direction from the light emitting unit 4 in such a manner that the overlap between the irradiation range 100A based on the light source 4A and the irradiation range 100B based on the light source 4B becomes larger. The distance L2 is an example of a reference distance. Hereinafter, it may be referred to as the reference distance L2.

[0093] In this example, the light emitting unit 4 irradiates light on the irradiation surface 220 in such a manner that the entire irradiation range 100A based on the light source 4A overlaps the substantially entire irradiation range 100B based on the light source 4B. In other words, when both the light source 4A and the light source 4B are turned on, the irradiation surface 220 has a substantially entire area that becomes an overlapping area 225 where the light from the light source 4A and the light from the light source 4B overlap and irradiate.

[0094] The irradiation surface 220 overlaps the entire irradiation range 100A and the entire irradiation range 100B, and its shape as viewed in the +z direction is close to a rectangular shape corresponding to the shapes of the light emitting surface 41 of the light source 4A and the light emitting surface 42 of the light source 4B.

[0095] In the following description, the shape of the irradiated surface 220 viewed in the +z direction may be indicated as a reference shape.

[0096] Furthermore, on the irradiated surface 210 which is a distance L1 closer than the reference distance L2 in the +z direction from the light emitting unit 4, the overlap between the irradiated range 100A by the light source 4A and the irradiated range 100B by the light source 4B becomes smaller than that on the irradiated surface 220. The distance L1 is an example of the first distance.

[0097] In addition, the light emitting unit 4 irradiates light on the irradiation surface 210 in such a manner that the irradiation range 100A based on the light source 4A and the irradiation range 100B based on the light source 4B are arranged in a staggered manner in a direction intersecting the z direction. As a result, the ratio of the overlapping portion of the irradiation range 100A and the irradiation range 100B of the irradiation surface 210 exceeds 50%, but the ratio of the non-overlapping portion of the irradiation range 100A and the irradiation range 100B also becomes more than 10%. In addition, the light quantity distribution on the irradiation surface 210 becomes uneven.

[0098] In this example, the light-emitting unit 4 irradiates light on the irradiation surface 210 such that the irradiation range 100A is arranged to be shifted in the +y direction with respect to the irradiation range 100B. As a result, on the irradiation surface 210, a partial region on the -y direction side of the irradiation range 100A overlaps with a partial region on the +y direction side of the irradiation range 100B. In other words, when both the light source 4A and the light source 4B are in the lit state, the irradiation surface 210 includes an irradiation region 211 where light from the light source 4A is irradiated and light from the light source 4B is not irradiated, an irradiation region 212 where light from the light source 4B is irradiated and light from the light source 4A is not irradiated, and an overlapping region 215 where light from the light source 4A and light from the light source 4B are irradiated overlappingly. On the irradiation surface 210, the irradiation region 211, the overlapping region 215, and the irradiation region 212 are arranged in sequence in the -y direction.

[0099] Moreover, since the irradiation range 100A and the irradiation range 100B are arranged to be shifted in the y direction on the irradiation surface 210, the shape of the irradiation surface 210 when viewed from the +z direction becomes a rectangular shape in which the ratio of the length in the y direction to the length in the x direction is larger than that of the above-described reference shape.

[0100] Moreover, although not shown in the drawings, the light-emitting unit 4 irradiates light on an irradiation surface that is farther from the light-emitting unit 4 in the +z direction than the reference distance L2 such that the proportion of the overlapping portion between the irradiation range 100A based on the light source 4A and the irradiation range 100B based on the light source 4B is slightly increased compared to the irradiation surface 220 at the reference distance L2. In this example, the light-emitting unit 4 irradiates light on an irradiation surface that is farther from the light-emitting unit 4 in the +z direction than the reference distance L2 such that the irradiation range 100A is arranged to be shifted in the -y direction with respect to the irradiation range 100B.

[0101] (Light-receiving unit 5)

[0102] The light-receiving unit 5 includes a light-receiving surface that diffuses in the x direction and the y direction and on which a plurality of light-receiving elements are arranged. Moreover, each light-receiving element on the light-receiving surface of the light-receiving unit 5 receives light emitted from the light sources 4A and 4B of the light-emitting unit 4 and reflected by the object. Then, the light-receiving unit 5 outputs an electric signal corresponding to the light received by the light-receiving element to the control unit 8.

[0103] Examples of the light-receiving element include a photodiode or a phototransistor.

[0104] (Drive control of the light-emitting unit 4)

[0105] Next, the drive of the light-emitting unit 4 performed by the light-emitting drive unit 6 according to the control of the control unit 8 will be described.

[0106] As described above, when the distance in the +z direction from the light-emitting unit 4 is different from the reference distance L2, sometimes the distance measurement of the object is affected because the irradiation range 100A based on the light source 4A and the irradiation range 100B based on the light source 4B are offset.

[0107] For example, the irradiation surface 210 at a distance L1 closer to the light-emitting unit 4 in the +z direction than the reference distance L2 includes an irradiation area 211 irradiated with light from the light source 4A and not irradiated with light from the light source 4B, an irradiation area 212 irradiated with light from the light source 4B and not irradiated with light from the light source 4A, and an overlapping area 215 irradiated with light from the light source 4A and light from the light source 4B overlappingly. And when both the light source 4A and the light source 4B are in the lit state, on the irradiation surface 210, in the irradiation areas 211, 212, and the overlapping area 215, the amount of light irradiated from the light-emitting unit 4 becomes uneven. More specifically, on the irradiation surface 210, light is irradiated to the overlapping area 215 from both the light source 4A and the light source 4B, so the amount of light irradiated to the overlapping area 215 becomes larger than the amount of light irradiated to the irradiation areas 211, 212.

[0108] And when both the light source 4A and the light source 4B are in the lit state, if there is an object in the overlapping area 215 of the irradiation surface 210, the amount of light irradiated to the object becomes excessive. In this case, for example, sometimes signal saturation occurs in the light-receiving element of the light-receiving unit 5 that receives the light reflected by the object existing in the overlapping area 215, so that the distance measurement of the object cannot be accurately performed.

[0109] In contrast, when the light-emitting unit 4 irradiates light to an object at a distance L1 different from the reference distance L2, the light-emitting drive unit 6 of the present embodiment drives the light-emitting unit 4 such that one of the light source 4A and the light source 4B is in the lit state and the other is in the extinguished state.

[0110] Figure 4 In Figure 4 (a) to Figure 4 (b) of Figure 4 are diagrams showing the irradiation surface 210 when one of the light source 4A and the light source 4B is in the lit state and the other is in the extinguished state. Figure 4 (a) of

[0111] shows the irradiation surface 210 when the light source 4A is in the lit state and the light source 4B is in the extinguished state, Figure 4 (a) to Figure 4As shown in (b), by setting one of the light sources 4A and 4B to the lit state and the other to the extinguished state, an overlapping region 215 where the light from the light source 4A and the light from the light source 4B are overlapped and irradiated is not easily formed on the irradiation surface 210 (refer to Figure 3 ). Thus, on the irradiation surface 210, the unevenness of the irradiated light amount is suppressed, and the excessive light amount irradiated onto the object is suppressed.

[0112] And, as shown in (a) of Figure 4 , when the light source 4A is set to the lit state and the light source 4B is set to the extinguished state, the shape of the irradiation surface 210 observed in the +z direction becomes a rectangular shape corresponding to the light emitting surface 41 of the light source 4A (refer to Figure 3 ). That is, when the light source 4A is set to the lit state and the light source 4B is set to the extinguished state, the shape of the irradiation surface 210 observed in the +z direction is substantially equal to the reference shape.

[0113] Similarly, as shown in (b) of Figure 4 , when the light source 4A is set to the extinguished state and the light source 4B is set to the lit state, the shape of the irradiation surface 210 observed in the +z direction becomes a rectangular shape corresponding to the light emitting surface 42 of the light source 4B (refer to Figure 3 ). That is, when the light source 4A is set to the extinguished state and the light source 4B is set to the lit state, the shape of the irradiation surface 210 observed in the +z direction is substantially equal to the reference shape.

[0114] Here, when irradiating light to an object at a reference distance L2 in the +z direction from the light emitting unit 4, the light emission driving unit 6 can drive the light emitting unit 4 in such a manner that both the light sources 4A and 4B are in the lit state.

[0115] As described above, when both the light sources 4A and 4B are set to the lit state, on the irradiation surface 220 at a reference distance L2 in the +z direction from the light emitting unit 4, the whole of the irradiation range 100A based on the light source 4A and the whole of the irradiation range 100B based on the light source 4B overlap. That is, on the irradiation surface 220, the entire region becomes an overlapping region 225 where the light from the light source 4A and the light from the light source 4B are irradiated, and the light amount irradiated from the light emitting unit 4 becomes uniform.

[0116] In this case, like the irradiation surface 210, the influence caused by the unevenness of the light amount irradiated from the light emitting unit 4 in the irradiation regions 211, 212, and the overlapping region 215 is not easily generated.

[0117] However, when a malfunction occurs even though the light quantity does not become uneven, for example, when there is an object with a high reflectivity such as a mirror or a whiteboard on the irradiation surface and the light incident on the light receiving unit 5 becomes excessive and causes a malfunction, etc., even when irradiating light on an object existing at the reference distance L2, the light emitting unit 4 can be driven in such a way that one of the light sources 4A and 4B is in the lit state and the other is in the extinguished state.

[0118] When an object is detected at a distance different from the reference distance L2, the light emission driving unit 6 of the present embodiment can drive the light emitting unit 4 in such a way that one of the light sources 4A and 4B is in the lit state and the other is in the extinguished state.

[0119] The detection of the object is performed by the control unit 8 based on the light reception result of the light receiving unit 5, for example. As described above, at a distance different from the reference distance L2 (for example, the distance L1), the light quantity irradiated on the irradiation surface 210 becomes uneven, and thus the light quantity irradiated on the object sometimes becomes excessive. In this case, the light reception quantity in the light receiving unit 5 that receives the light reflected by the object increases. When the light reception quantity in the light receiving unit 5 exceeds a preset threshold value, the control unit 8 detects the entry of the object into a distance different from the reference distance L2. As the threshold value of the light reception quantity used in the detection of the object by the control unit 8, for example, the light reception quantity at which signal saturation occurs in the light receiving element of the light receiving unit 5 can be set.

[0120] Moreover, the control unit 8 can detect the entry of the object into a distance different from the reference distance L2 (for example, the distance L1) by a detection sensor provided separately from the optical device 3.

[0121] Furthermore, for example, in the case where both the light sources 4A and 4B are set in the lit state to irradiate light on an object existing on the irradiation surface 220, and in the case where one of the light sources 4A and 4B is set in the lit state and the other is set in the extinguished state to irradiate light on an object existing on the irradiation surface 210, the light emission driving unit 6 of the present embodiment preferably keeps the magnitude of the power supplied to the lit light sources 4A and 4B unchanged. In other words, the light emission driving unit 6 preferably switches the light sources 4A and 4B between the lit state and the extinguished state while maintaining a state in which the current values of the light sources 4A and 4B are fixed.

[0122] Here, as another method of eliminating the excessive light quantity irradiated on the object in the overlapping region 215 of the irradiation surface 210, for example, a method of reducing the current values of the light sources 4A and 4B while keeping both the light sources 4A and 4B in the lit state can be considered. In this case, by reducing the current value, the light quantity emitted from the light sources 4A and 4B decreases, and thus the light quantity irradiated on the object in the overlapping region 215 decreases.

[0123] However, generally, if the current values of the light sources 4A and 4B are changed, conditions such as the rise time or fall time when the light is emitted from the light sources 4A and 4B are changed. Therefore, in order to accurately perform distance measurement using the light emitted from the light sources 4A and 4B, it is necessary to set correction parameters for correcting the control signals for driving the light sources 4A and 4B for each current value of the light sources 4A and 4B. In this case, the drive control of the light sources 4A and 4B by the light emission drive unit 6 according to the control signal from the control unit 8 easily becomes complicated.

[0124] In contrast, the light emission drive unit 6 of the present embodiment suppresses the complication of the drive of the light sources 4A and 4B by the light emission drive unit 6 by switching the light sources 4A and 4B between the lit state and the extinguished state while maintaining the state where the current values of the VCSELs constituting the light sources 4A and 4B are fixed.

[0125] In the present embodiment, for example, when one of the light sources 4A and 4B is set to the lit state and the other is set to the extinguished state, the control unit 8 preferably sets which of the light sources 4A and 4B is to be set to the lit state and which is to be set to the extinguished state based on the lighting history of the light sources 4A and 4B. Thereby, when one of the light sources 4A and 4B is set to the lit state and the other is set to the extinguished state, compared with the case where the light sources 4A and 4B are fixed to the lit state and the extinguished state, the drive control of the light emitting unit 4 corresponding to the lighting state of the light sources 4A and 4B can be performed.

[0126] Here, the lighting history indicates the state of switching the light sources 4A and 4B between the lit state and the extinguished state before performing the control of setting one of the light sources 4A and 4B to the lit state and the other to the extinguished state.

[0127] The control unit 8 can set which of the light sources 4A and 4B is to be set to the lit state and which is to be set to the extinguished state based on the total lighting time of the light sources 4A and 4B as an example of the lighting history of the light sources 4A and 4B. More specifically, when one of the light sources 4A and 4B is set to the lit state and the other is set to the extinguished state, the control unit 8 drives the light emitting unit 4 through the light emission drive unit 6 in such a manner that the light source with the shorter total lighting time among the light sources 4A and 4B is set to the lit state and the other light source with the longer total lighting time is made to be in the extinguished state. Thereby, when one of the light sources 4A and 4B is set to the lit state and the other is set to the extinguished state, compared with the case where the light sources 4A and 4B are fixed to the lit state and the extinguished state, the deviation of the total lighting time of the light sources 4A and 4B is suppressed.

[0128] Further, the control unit 8 can set which of the light sources 4A and 4B is to be in the lit state and which is to be in the extinguished state according to the lighting conditions of the light sources 4A and 4B before one of the light sources 4A and 4B is set to the lit state and the other is set to the extinguished state, which is an example of the lighting history of the light sources 4A and 4B. For example, when one of the light sources 4A and 4B is set to the lit state and the other is set to the extinguished state, the control unit 8 drives the light emitting unit 4 through the light emitting drive unit 6 in such a way that the one with the shorter previous lighting time among the light sources 4A and 4B is set to the lit state and the other with the longer previous lighting time is made to be in the extinguished state.

[0129] Here, in the light sources 4A and 4B, when in the lit state, heat is sometimes generated along with the light emission of the VCSEL. Also, in the light sources 4A and 4B, the longer the duration of the lit state, the higher the temperature rises due to the heat generated along with the light emission of the VCSEL, which may sometimes affect the light emission efficiency. In contrast, by setting which of the light sources 4A and 4B is to be in the lit state and which is to be in the extinguished state according to the lighting conditions of the light sources 4A and 4B before one of the light sources 4A and 4B is set to the lit state and the other is set to the extinguished state, the influence of heat generation on the light emission efficiency is suppressed.

[0130] In addition, in the present embodiment, the case where the light emitting unit 4 has two light sources 4A and 4B has been described as an example, but the number of light sources included in the light emitting unit 4 is not limited to two, and the light emitting unit 4 may have three or more light sources arranged such that the irradiation ranges overlap at the reference distance L2.

[0131] Further, when the light emitting unit 4 has three or more light sources, the light emitting drive unit 6 can make the number of light sources in the lit state and the number of light sources in the extinguished state different according to the distance of the object in the +z direction from the light emitting unit 4. For example, the light emitting drive unit 6 can be such that the closer the distance of the object in the +z direction from the light emitting unit 4, the fewer the number of light sources in the lit state and the more the number of light sources in the extinguished state.

[0132] (Another mode of driving control of the light emitting unit 4)

[0133] Next, another mode of driving the light emitting unit 4 by the light emitting drive unit 6 according to the control of the control unit 8 will be described.

[0134] In the above, the case where when irradiating an object at a distance different from the reference distance L2 (for example, the distance L1) by the light emitting unit 4, the light emitting drive unit 6 drives the light emitting unit 4 in such a way that one of the light sources 4A and 4B is in the lit state and the other is in the extinguished state has been described.

[0135] The light emission driving unit 6 can drive the light emitting unit 4 by switching between the following first mode and second mode without depending on the actual distance between the light emitting unit 4 and the object.

[0136] The first mode is a mode of irradiating an object at a first distance different from the reference distance L2, and is a mode of driving the light emitting unit 4 in such a manner that one of the light sources 4A and 4B is in the lit state and the other is in the extinguished state. As the first distance, for example, a distance shorter than the reference distance L2 can be set, and the above-described distance L1 can be exemplified.

[0137] Furthermore, the second mode is a mode for irradiating an object at a distance farther than the first distance, and is a mode of driving the light emitting unit 4 in such a manner that both the light sources 4A and 4B are in the lit state.

[0138] The light emission driving unit 6 can switch between the first mode and the second mode of the light emitting unit 4, for example, according to the distance from the light emitting unit 4 to the object detected by the control unit 8 based on the light reception result of the light receiving unit 5.

[0139] Incidentally, when it is predicted from the detection result of the object that the object will reach the first distance (for example, the distance L1), the light emission driving unit 6 can drive the light emitting unit 4 in the first mode. In this case, it is possible to suppress the irradiation of the object that has reached the first distance in a state where the irradiation range 100A of the light source 4A of the light emitting unit 4 and the irradiation range 100B of the light source 4B are displaced.

[0140] As a case where it is predicted that the object will reach the first distance, there is a case where the distance of the object detected by the control unit 8 based on the light reception result of the light receiving unit 5 approaches the first distance from a distance farther than the first distance over time.

[0141] The switching between the first mode and the second mode of the light emitting unit 4 by the light emission driving unit 6 can be performed based on an operation by the user using the distance measuring device 1.

[0142] Furthermore, the method of switching the light emitting unit 4 between the first mode and the second mode by the light emission driving unit 6 can be applied to Embodiments 2 and 3 described later.

[0143] [Embodiment 2]

[0144] Next, Embodiment 2 of the present invention will be described. The structures of the light emitting unit 4 and the light receiving unit 5 of the optical device 3 of the distance measuring device 1 in Embodiment 2 are different from those in Embodiment 1. In Embodiment 2, the same reference numerals are used for the same structures as in Embodiment 1, and the detailed description thereof is omitted here.

[0145] (Light emitting unit 4)

[0146] Figure 5 FIG. is a diagram showing the light sources 4C and 4D included in the light emitting unit 4 according to Embodiment 2 and the irradiation surface 230 irradiated with the light emitted from the light sources 4C and 4D. In Figure 5 , the right direction on the paper surface is defined as the +x direction, the upward direction on the paper surface is defined as the +y direction, the inside direction of the paper surface is defined as the +z direction, and the opposite directions are defined as the -x, -y, and -z directions. Further, in Figure 5 , the light emitting unit 4 and the irradiation surface 230 are shown offset in the vertical direction (±y direction) on the paper surface. However, in reality, the light emitting unit 4 and the irradiation surface 230 are arranged to face each other. In Figure 5 , the light emitting unit 4 is located on the front side direction (-z direction) of the paper surface, and the irradiation surface 230 is located on the inside direction (+z direction) of the paper surface. That is, Figure 5 FIG. is a view of the light emitting unit 4 emitting light as observed from the side opposite to the side from which the light is emitted from the light emitting unit 4.

[0147] Here, it is assumed that the distance in the +z direction from the light sources 4C and 4D to the irradiation surface 230 is the above-described reference distance L2 (see Figure 2 ).

[0148] The light emitting unit 4 according to the present embodiment includes a light source 4C that irradiates light to an irradiation range 100C (see Figure 6 described later) and a light source 4D that irradiates light to an irradiation range 100D different from the irradiation range 100C (see Figure 6 described later). The light emitting unit 4 irradiates the irradiation range 100C based on the light source 4C and the irradiation range 100D based on the light source 4D with light in parallel or overlapping manner. In this example, the light source 4C is an example of the first light source, the light source 4D is an example of the second light source, the irradiation range 100C is an example of the first irradiation range, and the irradiation range 100D is an example of the second irradiation range.

[0149] In the light emitting unit 4 according to the present embodiment, the light source 4C is arranged on the +y direction side with respect to the light source 4D.

[0150] The light sources 4C and 4D according to the present embodiment each have a light emitting surface 43 and 44 on which a plurality of VCSELs are arranged. In this example, the light emitting surface 43 of the light source 4C is juxtaposed on the +y direction side with respect to the light emitting surface 44 of the light source 4D.

[0151] The light emitting surfaces 43 of the light source 4C and 44 of the light source 4D are each divided into a plurality of light emitting zones including at least one VCSEL. Here, as an example, the light emitting surface 43 of the light source 4C is divided into 12 light emitting zones C1 to C12, four in the x direction and three in the y direction. In this example, the light emitting zones C1 to C12 are sequentially located from the upper left corner (-x direction side and +y direction side end) to the lower right corner (+x direction side and -y direction side end) of the light emitting surface 43. Similarly, as an example, the light emitting surface 44 of the light source 4D is divided into 12 light emitting zones D1 to D12, four in the x direction and three in the y direction. In this example, the light emitting zones D1 to D12 are sequentially located from the upper left corner (-x direction side and +y direction side end) to the lower right corner (+x direction side and -y direction side end) of the light emitting surface 44.

[0152] Each of the light emitting zones C1 to C12 of the light source 4C and D1 to D12 of the light source 4D is independently driven by the light emission driving unit 6 to emit light. The light emission driving unit 6 drives each of the light emitting zones of the light sources 4C and 4D according to a control signal from the control unit 8. Therefore, each of the light emitting zones C1 to C12 of the light source 4C and D1 to D12 of the light source 4D does not necessarily all emit light simultaneously, and a state where a part thereof emits light and the remaining part does not emit light can be adopted. In the present embodiment, a state where each of the light emitting zones C1 to C12 of the light source 4C and D1 to D12 of the light source 4D is in a light emitting state is referred to as the light emitting zone being in a lit state. And a state where each of the light emitting zones C1 to C12 of the light source 4C and D1 to D12 of the light source 4D is in a non-light emitting state is referred to as the light emitting zone being in an extinguished state.

[0153] Figure 6 In Figure 6 (a) to Figure 6 (b) are diagrams showing the light irradiation ranges 100C and 100D of the light sources 4C and 4D. Figure 6 (a) shows the irradiation range 100C based on the light source 4C, Figure 6 (b) shows the irradiation range 100D based on the light source 4D. Figure 6 In Figure 6 (a) to Figure 6 (b) are diagrams of the irradiation ranges 100C and 100D observed in the +z direction at a certain distance in the +z direction from the light emitting part 4.

[0154] As Figure 6As shown in (a) of FIG. , the irradiation range 100C includes irradiation sections P1 to P12 irradiated with light emitted from light-emitting sections C1 to C12 of the light source 4C. The irradiation sections P1 to P12 are sequentially located from the upper left corner (-x direction side and +y direction side end) to the lower right corner (+x direction side and -y direction side end) of the irradiation range 100C. Moreover, in the irradiation range 100C, a certain irradiation section Pi (i = 1 to 12) is irradiated with light emitted from the light-emitting section Ci given the same number i.

[0155] The shapes of the respective irradiation sections P1 to P12 of the irradiation range 100C are rectangular corresponding to the shapes of the respective light-emitting sections C1 to C12 of the light-emitting surface 43. And the shape of the irradiation range 100C as a whole is rectangular corresponding to the shape of the light-emitting surface 43.

[0156] As Figure 6 shown in (b) of FIG. , the irradiation range 100D includes irradiation sections Q1 to Q12 irradiated with light emitted from light-emitting sections D1 to D12 of the light source 4D. The irradiation sections Q1 to Q12 are sequentially located from the upper left corner (-x direction side and +y direction side end) to the lower right corner (+x direction side and -y direction side end) of the irradiation range 100D. Moreover, in the irradiation range 100D, a certain irradiation section Qi (i = 1 to 12) is irradiated with light emitted from the light-emitting section Di given the same number i.

[0157] The shapes of the respective irradiation sections Q1 to Q12 of the irradiation range 100D are rectangular corresponding to the shapes of the respective light-emitting sections D1 to D12 of the light-emitting surface 44. And the shape of the irradiation range 100D as a whole is rectangular corresponding to the shape of the light-emitting surface 44.

[0158] The light-emitting unit 4 of the present embodiment irradiates light on the irradiation surface 230 at a distance in the +z direction from the light-emitting unit 4 that is the reference distance L2, so as to increase the overlap between the irradiation range 100C based on the light source 4C and the irradiation range 100D based on the light source 4D.

[0159] In this example, as Figure 5 shown, the light-emitting unit 4 irradiates light on the irradiation surface 230 so that the whole of the irradiation range 100C based on the light source 4C overlaps with the whole of the irradiation range 100D based on the light source 4D. In this case, on the irradiation surface 230, the irradiation sections P1 to P12 of the irradiation range 100C based on the light source 4C (refer to Figure 6 (a) of FIG. ) and the irradiation sections Q1 to Q12 of the irradiation range 100D based on the light source 4D (refer to Figure 6 (b) of FIG. ) overlap with each other. Incidentally, on the irradiation surface 230, the irradiation section Pi of the irradiation range 100C overlaps with the irradiation section Qi of the irradiation range 100D given the same number i.

[0160] Moreover, on the irradiation surface 230 of the present embodiment, the irradiation sub-region Pi of the irradiation range 100C does not overlap with the irradiation sub-region Qj of the irradiation range 100D given a number j different from the number i.

[0161] For example, on the irradiation surface 230, the irradiation sub-region P1 of the irradiation range 100C overlaps with the irradiation sub-region Q1 of the irradiation range 100D. On the other hand, on the irradiation surface 230, the irradiation sub-region P1 of the irradiation range 100C does not overlap with the irradiation sub-regions Q2, Q5, and Q6 adjacent to the irradiation sub-region Q1 within the irradiation range 100D.

[0162] Thus, in the light-emitting unit 4 of the present embodiment, when the light sources 4C and 4D are simultaneously lit by the light-emitting drive unit 6, by independently controlling the respective light-emitting sub-regions C1 to C12 of the light source 4C and the respective light-emitting sub-regions D1 to D12 of the light source 4D, the irradiation surface 230 can be divided into a plurality of sub-regions to irradiate light.

[0163] In addition, in the following description, on the irradiation surface 230, the plurality of sub-regions capable of dividing and irradiating light by the light sources 4C and 4D are labeled as sub-regions R1 to R12 of the irradiation surface 230. On the irradiation surface 230, when the light-emitting sub-region Ci of the light source 4C and the light-emitting sub-region Di of the light source 4D are set to the lit state, light from the light-emitting sub-region Ci and light from the light-emitting sub-region Di are overlapped and irradiated to the sub-region Ri with the same number i. That is, in the sub-region Ri of the irradiation surface 230, the irradiation sub-region Pi based on the irradiation range 100C of the light source 4C overlaps with the irradiation sub-region Qi based on the irradiation range 100D of the light source 4D.

[0164] In addition, regarding the relationship between the irradiation sub-regions P1 to P12 based on the irradiation range 100C of the light source 4C and the irradiation sub-regions Q1 to Q12 based on the irradiation range 100D of the light source 4D on an irradiation surface (the irradiation surface 240 described later) whose distance in the +z direction from the light-emitting unit 4 is different from the reference distance L2, it will be described later.

[0165] (Light-receiving unit 5)

[0166] Figure 7 FIG. is an example of the structure of the light-receiving unit 5 to which Embodiment 2 is applied, and is a diagram showing the light-receiving surface 50 of the light-receiving unit 5 and the above-described irradiation surface 230. In Figure 7 it, the right direction of the paper surface is set as the +x direction, the upper direction of the paper surface is set as the +y direction, the back side of the paper surface is set as the +z direction, and the opposite directions are set as -x, -y, and -z directions. In addition, in Figure 7In the figure, the light receiving unit 5 and the irradiation surface 230 are shown offset in the vertical direction (±y direction) of the paper surface. In reality, however, the light receiving unit 5 and the irradiation surface 230 are arranged opposite to each other. In Figure 7 the figure, the light receiving unit 5 is located on the front side direction (-z direction) of the paper surface, and the irradiation surface 230 is located on the back side direction (+z direction) of the paper surface.

[0167] The light receiving unit 5 includes a light receiving surface 50 that diffuses in the x and y directions and has a plurality of light receiving elements arranged thereon.

[0168] The light receiving surface 50 is divided into a plurality of light receiving partitions A1 to A12 corresponding to the partitions R1 to R12 of the irradiation surface 230. Specifically, the light receiving surface 50 is divided into a total of 12 light receiving partitions A1 to A12, four in the x direction and three in the y direction. In this example, the light receiving partitions A1 to A12 are sequentially located from the upper left corner (-x direction side and +y direction side end) to the lower right corner (+x direction side and -y direction side end) of the light receiving surface 50.

[0169] Each of the light receiving partitions A1 to A12 receives light emitted from the light emitting partitions C1 to C12 of the light source 4C and the light emitting partitions D1 to D12 of the light source 4D and reflected by an object present in the partition Ri with the same number. Each of the light receiving partitions A1 to A12 is independently driven by a light receiving drive unit 7 (refer to Figure 1 ) to perform a light receiving operation.

[0170] (Drive control of the light emitting unit 4)

[0171] Next, the drive of the light emitting unit 4 performed by the light emitting drive unit 6 under the control of the control unit 8 will be described.

[0172] The light emitting drive unit 6 of the present embodiment drives the light sources 4C and 4D, for example, on the irradiation surface 230, such that light is irradiated to adjacent partitions R1 to R12 among the partitions R1 to R12 at different times. In other words, the light emitting drive unit 6 drives the light sources 4C and 4D on the irradiation surface 230 such that the light emitting partitions C1 to C12 of the light source 4C and the light emitting partitions D1 to D12 of the light source 4D that emit light toward adjacent partitions R1 to R12 among the partitions R1 to R12 emit light at different times.

[0173] Figure 8 In Figure 8 (a) to Figure 8 (b) of the figure are diagrams showing an example of the state of the irradiation surface 230 when the light sources 4C and 4D are driven such that light is irradiated to adjacent partitions R1 to R12 at different times. In Figure 8 (a) to Figure 8In (b), the right direction of the paper surface is set as the +x direction, the upper direction of the paper surface is set as the +y direction, the inner side of the paper surface is set as the +z direction, and the opposite directions are set as the -x, -y, and -z directions. And, in Figure 8 (a) to Figure 8 In (b), the divided areas R1 to R12 of the irradiation surface 230 that are irradiated with light by the light sources 4C and 4D are indicated by hatched lines.

[0174] The light emission driving unit 6 drives the light sources 4C and 4D in such a manner that, for example, at different times, light is irradiated to the group composed of divided areas R1, R3, R6, R8, R9, and R11 and the group composed of divided areas R2, R4, R5, R7, R10, and R12 that are arranged in a staggered pattern on the irradiation surface 230.

[0175] Specifically, at a preset first time, the light emission divided areas C1, C3, C6, C8, C9, and C11 of the light source 4C are set to the lit state, the light emission divided areas D1, D3, D6, D8, D9, and D11 of the light source 4D are set to the lit state, and the light emission divided areas C2, C4, C5, C7, C10, and C12 of the light source 4C are set to the extinguished state, and the light emission divided areas D2, D4, D5, D7, D10, and D12 of the light source 4D are set to the extinguished state.

[0176] Thereby, at the first time, as shown in Figure 8 (a), the divided areas R1, R3, R6, R8, R9, and R11 of the irradiation surface 230 are respectively irradiated with light emitted from the light emission divided areas C1, C3, C6, C8, C9, and C11 of the light source 4C and the light emission divided areas D1, D3, D6, D8, D9, and D11 of the light source 4D.

[0177] As described above, in a certain divided area Ri of the irradiation surface 230, the irradiation divided area Pi of the irradiation range 100C overlaps with the irradiation divided area Qi of the irradiation range 100D having the same number i. On the other hand, in the divided area Ri, the irradiation divided area Pi of the irradiation range 100C does not overlap with the irradiation divided area Qj of the irradiation range 100D having a number j different from the number i, and the irradiation divided area Qi of the irradiation range 100D does not overlap with the irradiation divided area Pk of the irradiation range 100C having a number k different from the number i.

[0178] Therefore, at the first time, the light emitted from the light emission divided areas C1, C3, C6, C8, C9, and C11 of the light source 4C and the light emission divided areas D1, D3, D6, D8, D9, and D11 of the light source 4D does not irradiate the divided areas R2, R4, R5, R7, R10, and R12 of the irradiation surface 230.

[0179] Further, at a second time different from the first time, the light emission driving unit 6 sets the light emission sections C2, C4, C5, C7, C10, C12 of the light source 4C to the lit state, sets the light emission sections D2, D4, D5, D7, D10, D12 of the light source 4D to the lit state, and sets the light emission sections C1, C3, C6, C8, C9, C11 of the light source 4C to the extinguished state, and sets the light emission sections D1, D3, D6, D8, D9, D11 of the light source 4D to the extinguished state.

[0180] Thereby, at the second time, as shown in (b) of Figure 8 , the light emitted from the light emission sections C2, C4, C5, C7, C10, C12 of the light source 4C and the light emission sections D2, D4, D5, D7, D10, D12 of the light source 4D is respectively irradiated onto the sections R2, R4, R5, R7, R10, R12 of the irradiation surface 230.

[0181] Further, at the second time, the light emitted from the light emission sections C2, C4, C5, C7, C10, C12 of the light source 4C and the light emission sections D2, D4, D5, D7, D10, D12 of the light source 4D does not irradiate the sections R1, R3, R6, R8, R9, R11 of the irradiation surface 230.

[0182] In addition, the second time can be set, for example, as a time consecutive to the first time.

[0183] Thus, according to the light emitting unit 4 of the present embodiment, on the irradiation surface 230 at a distance of the reference distance L2 in the +z direction from the light emitting unit 4, the group composed of the sections R1, R3, R6, R8, R9, R11 and the group composed of the adjacent sections R2, R4, R5, R7, R10, R12 can be irradiated with light at different times.

[0184] Moreover, the light receiving unit 5 can obtain the light reception results for each section R1 to R12 of the irradiation surface 230 by obtaining the light reflected by the irradiation surface 230 at different times in the group composed of the light receiving sections A1, A3, A6, A8, A9, A11 and the group composed of the light receiving sections A2, A4, A5, A7, A10, A12. Thereby, in the distance measuring device 1 of the present embodiment, compared with the case where the light emission sections C1 to C12 of the light source 4C and the light emission sections D1 to D12 of the light source 4D are simultaneously set to the lit state and the sections R1 to R12 of the irradiation surface 230 are simultaneously irradiated with light, the distance measurement of the object present on the irradiation surface 230 can be performed with higher accuracy.

[0185] Here, in Embodiment 2, similarly to Embodiment 1, when the distance in the +z direction from the light emitting unit 4 is different from the reference distance L2, the irradiation range 100C based on the light source 4C and the irradiation range 100D based on the light source 4D are sometimes offset, which sometimes affects the distance measurement of the object.

[0186] Figure 9 middle, Figure 9 (a)~ Figure 9 (b) is for a distance L1 (reference distance L2) closer to the light emitting unit 4 in the +z direction. Figure 2 ) is a diagram for explaining the irradiation range 100C of the light source 4C and the irradiation range 100D of the light source 4D on the irradiation surface 240. Figure 9 (a)~ Figure 9 In (b), the right direction of the paper is set as the +x direction, the upper direction of the paper is set as the +y direction, the back side of the paper is set as the +z direction, and the opposite directions are set as the -x, -y, and -z directions. Figure 9 (a)~ Figure 9 In (b), the irradiation range 100C of the light source 4C is indicated by a solid line, and the irradiation range 100D of the light source 4D is indicated by a dotted line.

[0187] Figure 9 (a) shows the relationship between the irradiation subareas P1, P3, P6, P8, P9, P11 of the irradiation range 100C and the irradiation subareas Q1, Q3, Q6, Q8, Q9, Q11 of the irradiation range 100D on the irradiation surface 240. Figure 9 In (a), when the light-emitting partitions C1, C3, C6, C8, C9, C11 of the light source 4C and the light-emitting partitions D1, D3, D6, D8, D9, D11 of the light source 4D are set to the lighting state, the light-irradiated parts are indicated by hatching on the irradiation surface 240.

[0188] Figure 9 (b) shows the relationship between the irradiation subareas P2, P4, P5, P7, P10, P12 of the irradiation range 100C and the irradiation subareas Q2, Q4, Q5, Q7, Q10, Q12 of the irradiation range 100D on the irradiation surface 240. Figure 9 In (b), when the light-emitting partitions C2, C4, C5, C7, C10, C12 of the light source 4C and the light-emitting partitions D2, D4, D5, D7, D10, D12 of the light source 4D are set to the lighting state, the light-irradiated parts are indicated by hatching on the irradiation surface 240.

[0189] like Figure 9 (a)~ Figure 9As shown in FIG. (b), the light emitting unit 4 of the present embodiment irradiates light on the irradiation surface 240 such that the irradiation range 100C of the light source 4C is arranged offset in the +y direction with respect to the irradiation range 100D of the light source 4D.

[0190] In this case, on the irradiation surface 240, the irradiation sub-region Pi of the irradiation range 100C and the irradiation sub-region Qi of the irradiation range 100D given the same number i are arranged offset in the +y direction.

[0191] For example, as Figure 9 shown in FIG. (a), if the light emitting sub-regions C1, C3, C6, C8, C9, C11 of the light source 4C and the light emitting sub-regions D1, D3, D6, D8, D9, D11 of the light source 4D given the same numbers are simultaneously set to the lit state, then on the irradiation surface 240, the irradiation sub-regions P1, P3, P6, P8, P9, P11 and the irradiation sub-regions Q1, Q3, Q6, Q8, Q9, Q11 are arranged offset in the y direction. In this case, on the irradiation surface 240, the irradiation sub-regions P1, P3, P6, P8, P9, P11 and the irradiation sub-regions Q1, Q3, Q6, Q8, Q9, Q11 overlap in a part of the region in the y direction and do not overlap in a part of the region in the y direction.

[0192] And, as Figure 9 shown in FIG. (b), if the light emitting sub-regions C2, C4, C5, C7, C10, C12 of the light source 4C and the light emitting sub-regions D2, D4, D5, D7, D10, D12 of the light source 4D given the same numbers are simultaneously set to the lit state, then on the irradiation surface 240, the irradiation sub-regions P2, P4, P5, P7, P10, P12 and the irradiation sub-regions Q2, Q4, Q5, Q7, Q10, Q12 are arranged offset in the y direction. In this case, on the irradiation surface 240, the irradiation sub-regions P2, P4, P5, P7, P10, P12 and the irradiation sub-regions Q2, Q4, Q5, Q7, Q10, Q12 overlap in a part of the region in the y direction and do not overlap in a part of the region in the y direction.

[0193] Figure 10 In Figure 10 FIGS. (a) to Figure 10 FIG. (b) are diagrams for explaining the overlap of the irradiation range 100C based on the light source 4C and the irradiation range 100D based on the light source 4D on the irradiation surface 240. In Figure 10 FIGS. (a) to Figure 10 FIG. (b), the right direction of the paper surface is set as the +x direction, the upper direction of the paper surface is set as the +y direction, the inside direction of the paper surface is set as the +z direction, and the opposite directions are set as the -x, -y, -z directions. And, in Figure 10 FIGS. (a) to Figure 10In (b) thereof, the irradiation range 100C of the light source 4C is represented by a solid line, and the irradiation range 100D of the light source 4D is represented by a dashed line.

[0194] Moreover, Figure 10 shows the irradiation sub-regions P1 and P5 of the irradiation range 100C and the irradiation sub-regions Q1 and Q5 of the irradiation range 100D in the irradiation ranges 100C and 100D on the irradiation surface 240.

[0195] In Figure 10 (a) thereof, the light-emitting sub-region C1 of the light source 4C and the light-emitting sub-region D1 of the light source 4D are set to the lit state, and the light-emitting sub-region C5 of the light source 4C and the light-emitting sub-region D5 of the light source 4D are set to the extinguished state.

[0196] Moreover, Figure 10 (b) thereof, the light-emitting sub-region C5 of the light source 4C and the light-emitting sub-region D5 of the light source 4D are set to the lit state, and the light-emitting sub-region C1 of the light source 4C and the light-emitting sub-region D1 of the light source 4D are set to the extinguished state.

[0197] Moreover, Figure 10 (a) to Figure 10 (b) thereof, the irradiation sub-regions P1 and P5 irradiated by the light-emitting sub-regions C1 and C5 of the lit light source 4C and the irradiation sub-regions Q1 and Q5 irradiated by the light-emitting sub-regions D1 and D5 of the lit light source 4D are represented by hatched lines.

[0198] As Figure 10 (a) to Figure 10 (b) shown, the light-emitting unit 4 of the present embodiment irradiates light on the irradiation surface 240 such that the irradiation sub-region P1 is arranged to be shifted in the +y direction with respect to the irradiation sub-region Q1. Accordingly, on the irradiation surface 240, a partial region on the -y direction side of the irradiation sub-region P1 overlaps with a partial region on the +y direction side of the irradiation sub-region Q1.

[0199] Similarly, the light-emitting unit 4 irradiates light on the irradiation surface 240 such that the irradiation sub-region P5 is arranged to be shifted in the +y direction with respect to the irradiation sub-region Q5. Accordingly, on the irradiation surface 240, a partial region on the -y direction side of the irradiation sub-region P5 overlaps with a partial region on the +y direction side of the irradiation sub-region Q5.

[0200] Moreover, on the irradiation surface 240, the irradiation sub-region Q1 is arranged to be shifted in the -y direction with respect to the irradiation sub-region P1, and accordingly, a partial region on the -y direction side of the irradiation sub-region Q1 overlaps with a partial region on the +y direction side of the irradiation sub-region P5 that is adjacent to the irradiation sub-region P1 on the -y direction side.

[0201] Moreover, on the irradiation surface 240, the irradiation sub-region P5 is arranged offset in the +y direction with respect to the irradiation sub-region Q5. As a result, a partial region on the +y direction side of the irradiation sub-region P5 overlaps with a partial region on the -y direction side of the irradiation sub-region Q1 that is adjacent to the irradiation sub-region Q5 on the +y direction side.

[0202] Here, in the light-emitting unit 4 of the second embodiment, it is conceivable that at a preset third time, the light-emitting sub-region C1 of the light source 4C and the light-emitting sub-region D1 of the light source 4D are simultaneously set to the lit state, and the light-emitting sub-region C5 of the light source 4C and the light-emitting sub-region D5 of the light source 4D are set to the extinguished state. In this case, as Figure 10 shown in (a) of, on the irradiation surface 240, the irradiation sub-region Q1 overlaps with the irradiation sub-region P1, which causes the light from the light-emitting sub-region D1 of the light source 4D to irradiate the irradiation sub-region P5 where the light-emitting sub-regions C1 and C5 of the light source 4C do not irradiate light.

[0203] In addition, in this example, the light-emitting sub-region C5 of the light source 4C is an example of the first light-emitting sub-region that irradiates the first irradiation sub-region, that is, the irradiation sub-region P5, and the light-emitting sub-region C1 of the light source 4C is an example of the third light-emitting sub-region that irradiates the third irradiation sub-region adjacent to the irradiation sub-region P5, that is, the irradiation sub-region P1.

[0204] Moreover, the light-emitting sub-region D5 of the light source 4D is an example of the second light-emitting sub-region that irradiates the second irradiation sub-region, that is, the irradiation sub-region Q5, and the light-emitting sub-region D1 of the light source 4D is an example of the fourth light-emitting sub-region that irradiates the fourth irradiation sub-region adjacent to the irradiation sub-region Q5, that is, the irradiation sub-region Q1.

[0205] Furthermore, in the light-emitting unit 4 of the second embodiment, it is conceivable that at a fourth time different from the third time, the light-emitting sub-region C5 of the light source 4C and the light-emitting sub-region D5 of the light source 4D are simultaneously set to the lit state, and the light-emitting sub-region C1 of the light source 4C and the light-emitting sub-region D1 of the light source 4D are set to the extinguished state. In this case, as Figure 10 shown in (b) of, on the irradiation surface 240, the light from the light-emitting sub-region C5 of the light source 4C irradiates the irradiation sub-region Q1 where the light-emitting sub-regions D1 and D5 of the light source 4D do not irradiate light.

[0206] Thus, in the light-emitting unit 4 of the second embodiment, if the light-emitting sub-region Ci of the light source 4C that irradiates the irradiation sub-region Pi and the light-emitting sub-region Di of the light source 4D that irradiates the irradiation sub-region Qi with the same number are simultaneously set to the lit state, then even when the light-emitting sub-region Cj of the light source 4C that irradiates the irradiation sub-region Pj adjacent to the irradiation sub-region Pi in the -y direction is set to the extinguished state, light will irradiate the irradiation sub-region Pj.

[0207] In this case, on the irradiation surface 240, different from the irradiation surface 230 at the above-mentioned reference distance L2, it is difficult to irradiate the light to the irradiation sections Pi, Qi and the adjacent irradiation sections Pj, Qj at different times.

[0208] Therefore, the light-emitting driving unit 6 of the present embodiment drives the light-emitting unit 4 at a distance L1 different from the reference distance L2 at a preset third time, so that one of the light-emitting sections Ci of the light source 4C irradiating the irradiation section Pi and the light-emitting section Di of the light source 4D irradiating the irradiation section Qi with the same number is in the lighting state and the other is in the extinguished state. In addition, at the third time, the light-emitting driving unit 6 drives the light-emitting unit 4 so that the light-emitting section Cj of the light source 4C irradiating the irradiation section Pj adjacent to the irradiation section Pi and the light-emitting section Dj of the light source 4D irradiating the irradiation section Qj adjacent to the irradiation section Qi are in the extinguished state.

[0209] And at a fourth time different from the third time, the light-emitting unit 4 is driven so that one of the light-emitting section Cj of the light source 4C irradiating the irradiation section Pj adjacent to the irradiation section Pi and the light-emitting section Dj of the light source 4D irradiating the irradiation section Qj adjacent to the irradiation section Qi is in the lighting state and the other is in the extinguished state. In addition, at the fourth time, the light-emitting driving unit 6 drives the light-emitting unit 4 so that the light-emitting section Ci of the light source 4C irradiating the irradiation section Pi and the light-emitting section Di of the light source 4D irradiating the irradiation section Qi are in the extinguished state.

[0210] Figure 11 FIG. is an example of the drive control of the light-emitting unit 4 by the light-emitting driving unit 6 at the above-mentioned third time. In Figure 11 the part where the light is irradiated by the light-emitting unit 4 on the irradiation surface 240 is indicated by hatching.

[0211] In Figure 11 the light-emitting sections C1, C3, C6, C8, C9, C11 of the light source 4C are set to the lighting state and the light-emitting sections D1, D3, D6, D8, D9, D11 of the light source 4D are set to the extinguished state, and the light-emitting sections C2, C4, C5, C7, C10, C12 of the light source 4C and the light-emitting sections D2, D4, D5, D7, D10, D12 of the light source 4D are set to the extinguished state.

[0212] As Figure 11 shown, the light-emitting driving unit 6 drives the light-emitting unit 4 at a distance L1 different from the reference distance L2, so that one of the light-emitting section Ci of the light source 4C and the light-emitting section Di of the light source 4D with the same number is in the lighting state and the other is in the extinguished state, whereby the irradiation sections Pi, Qi and the adjacent irradiation sections Pj, Qj can be irradiated with light at different times.

[0213] Accordingly, compared with the case where the light-emitting driving unit 6 sets the light-emitting partitions Ci of the light source 4C and the light-emitting partitions Di of the light source 4D with the same number to the lit state at a distance L1 different from the reference distance L2, the distance measurement of the object present on the irradiation surface 240 can be performed with higher accuracy.

[0214] Here, in the present embodiment, similarly to the first embodiment, it is possible to set which of the light-emitting partitions Ci of the light source 4C and the light-emitting partitions Di of the light source 4D is to be set to the lit state and which is to be set to the extinguished state according to the lighting history of the light source 4C and the light source 4D.

[0215] For example, in the above example, the sum of the total lighting times of the light-emitting partitions C1, C3, C6, C8, C9, and C11 of the light source 4C is compared with the sum of the total lighting times of the light-emitting partitions D1, D3, D6, D8, D9, and D11 of the light source 4D, and the light-emitting unit 4 is driven by the light-emitting driving unit 6 in such a way that the one with the shorter sum of the total lighting times becomes the lit state and the other with the longer sum of the total lighting times becomes the extinguished state. Accordingly, when one of the light-emitting partitions C1, C3, C6, C8, C9, and C11 of the light source 4C and the light-emitting partitions D1, D3, D6, D8, D9, and D11 of the light source 4D is set to the lit state and the other is set to the extinguished state, the deviation of the total lighting times of the light sources 4C and 4D is suppressed compared with the case where the light-emitting partitions fixed to the lit state and the extinguished state.

[0216] In addition, regarding the total lighting time, it is not necessary to strictly compare the sum of the lighting times of the light-emitting partitions of each light source itself in the lighting history of each light source. For example, the total lighting time can be compared after subtracting the time such as lighting with an output that has little influence on the life of the light source from the lighting times of the light-emitting partitions of each light source. And when the light-emitting partitions of each light source emit pulsed light at the same time interval, the total number of lighting times of the light-emitting partitions of each light source can be compared as the lighting history of the light source.

[0217] [Embodiment 3]

[0218] Next, Embodiment 3 of the present invention will be described. The structures of the light-emitting unit 4 and the light-receiving unit 5 included in the optical device 3 of the distance measuring device 1 according to Embodiment 3 are different from those of Embodiments 1 and 2. In Embodiment 3, the same reference numerals are used for the same structures as those in Embodiments 1 and 2, and the detailed description thereof is omitted here.

[0219] (Light-emitting unit 4)

[0220] Figure 12 In Figure 12 of (a) to Figure 12Figure (c) is a diagram for explaining the structures of the light sources 4E, 4F, and 4G included in the light-emitting unit 4 of Embodiment 3. In Figure 12 Figure (a) to Figure 12 Figure (c), the right direction on the paper surface is defined as the +x direction, the upward direction on the paper surface is defined as the +y direction, the inside direction of the paper surface is defined as the +z direction, and the opposite directions are defined as the -x, -y, and -z directions, respectively. Figure 12 Figure (a) to Figure 12 Figure (c) are views of the light sources 4E, 4F, and 4G of the light-emitting unit 4 emitting light as observed from the side opposite to the side from which the light-emitting unit 4 emits light.

[0221] Figure 13 Figure is a diagram showing the light sources 4E, 4F, and 4G included in the light-emitting unit 4 of Embodiment 3 and the irradiation surface 250 irradiated with the light emitted from the light sources 4E, 4F, and 4G. In Figure 13 , the right direction on the paper surface is defined as the +x direction, the upward direction on the paper surface is defined as the +y direction, the inside direction of the paper surface is defined as the +z direction, and the opposite directions are defined as the -x, -y, and -z directions, respectively. In addition, in Figure 13 , the light-emitting unit 4 and the irradiation surface 250 are shown shifted in the vertical direction (±y direction), but actually, the light-emitting unit 4 and the irradiation surface 250 are arranged to face each other. In Figure 13 , the light-emitting unit 4 is located on the front side direction (-z direction) of the paper surface, and the irradiation surface 250 is located on the inside direction (+z direction) of the paper surface. That is, Figure 13 Figure is a view of the light-emitting unit 4 emitting light as observed from the side opposite to the side from which the light-emitting unit 4 emits light.

[0222] Here, it is assumed that the distance in the +z direction from the light sources 4E, 4F, and 4G of the light-emitting unit 4 to the irradiation surface 250 is the above-mentioned reference distance L2 (refer to Figure 2 ).

[0223] The light-emitting unit 4 of the present embodiment includes a light source 4E that irradiates light to the irradiation range 100E, a light source 4F that irradiates light to an irradiation range 100F different from the irradiation range 100E, and a light source 4G that irradiates light to an irradiation range 100G different from the irradiation ranges 100E and 100F. The light-emitting unit 4 irradiates light to the irradiation range 100E based on the light source 4E, the irradiation range 100F based on the light source 4F, and the irradiation range 100G based on the light source 4G in parallel or overlapping manner.

[0224] In the light-emitting unit 4 of the present embodiment, the light source 4E, the light source 4F, and the light source 4G are arranged in sequence along the -y direction.

[0225] The light sources 4E, 4F, and 4G of this embodiment each have light emitting surfaces 45, 46, and 47 on which a plurality of VCSELs are arranged. In this example, the light emitting surface 45 of the light source 4E, the light emitting surface 46 of the light source 4F, and the light emitting surface 47 of the light source 4G are arranged side by side in the -y direction in sequence.

[0226] As an example, the light emitting surface 45 of the light source 4E is divided into a total of 24 light emitting regions Emn (m is a natural number from 1 to 6, n is a natural number from 1 to 4) in the x direction and 4 in the y direction. m represents the position of the light emitting region Emn on the light emitting surface 45 in the x direction, and n represents the position of the light emitting region Emn on the light emitting surface 45 in the -y direction. For example, the light emitting region E11 is arranged at the position that is the 1st in the x direction and the 1st in the -y direction from the upper left corner (-x direction side and +y direction side end) of the light emitting surface 45 on the light emitting surface 45. The same applies to the light emitting regions Fmn of the light source 4F and the light emitting regions Gmn of the light source 4G described below.

[0227] As an example, the light emitting surface 46 of the light source 4F is divided into a total of 24 light emitting regions Fmn (m is a natural number from 1 to 6, n is a natural number from 1 to 4) in the x direction and 4 in the y direction.

[0228] As an example, the light emitting surface 47 of the light source 4G is divided into a total of 24 light emitting regions Gmn (m is a natural number from 1 to 6, n is a natural number from 1 to 4) in the x direction and 4 in the y direction.

[0229] Each light emitting region Emn of the light source 4E, each light emitting region Fmn of the light source 4F, and each light emitting region Gmn of the light source 4G are independently driven by the light emitting driving unit 6 to emit light. The light emitting driving unit 6 drives each light emitting region of the light sources 4E, 4F, and 4G according to the control signal from the control unit 8. Therefore, not all of the light emitting regions Emn of the light source 4E, the light emitting regions Fmn of the light source 4F, and the light emitting regions Gmn of the light source 4G necessarily emit light at the same time, and a state where a part of them emits light and the remaining part does not emit light can be adopted. In this embodiment, the state where each light emitting region Emn of the light source 4E, each light emitting region Fmn of the light source 4F, and each light emitting region Gmn of the light source 4G is emitting light is referred to as the light emitting region being in the lit state. And the state where each light emitting region Emn of the light source 4E, each light emitting region Fmn of the light source 4F, and each light emitting region Gmn of the light source 4G is not emitting light is referred to as the light emitting region being in the extinguished state.

[0230] The light emitting driving unit 6 of this embodiment divides each light emitting region Emn of the light source 4E, each light emitting region Fmn of the light source 4F, and each light emitting region Gmn of the light source 4G into three groups, and drives them in such a way that they emit light at different times for each group.

[0231] In this example, each light-emitting section Emn of the light source 4E, each light-emitting section Fmn of the light source 4F, and each light-emitting section Gmn of the light source 4G are divided into a first group that irradiates light on the sections S1n and S4n of the irradiation surface 250, a second group that irradiates light on the sections S2n and S5n, and a third group that irradiates light on the sections S3n and S6n. The light emission driving unit 6 causes the light-emitting sections Emn of the light source 4E, the light-emitting sections Fmn of the light source 4F, and the light-emitting sections Gmn of the light source 4G belonging to each group to emit light in the order of the first group, the second group, and the third group.

[0232] Specifically, the first group includes the light-emitting sections E11, E12, E13, E14, E41, E42, E43, E44 of the light source 4E, the light-emitting sections F11, F12, F13, F14, F41, F42, F43, F44 of the light source 4F, and the light-emitting sections G11, G12, G13, G14, G41, G42, G43, G44 of the light source 4G.

[0233] Further, the second group includes the light-emitting sections E21, E22, E23, E24, E51, E52, E53, E54 of the light source 4E, the light-emitting sections F21, F22, F23, F24, F51, F52, F53, F54 of the light source 4F, and the light-emitting sections G21, G22, G23, G24, G51, G52, G53, G54 of the light source 4G.

[0234] Further, the third group includes the light-emitting sections E31, E32, E33, E34, E61, E62, E63, E64 of the light source 4E, the light-emitting sections F31, F32, F33, F34, F61, F62, F63, F64 of the light source 4F, and the light-emitting sections G31, G32, G33, G34, G61, G62, G63, G64 of the light source 4G.

[0235] Further, the light-emitting unit 4 of the present embodiment irradiates light on the irradiation surface 250 at a distance in the +z direction from the light-emitting unit 4 that is the reference distance L2, such that the entirety of the irradiation range 100E based on the light source 4E, the entirety of the irradiation range 100F based on the light source 4F, and the entirety of the irradiation range 100G based on the light source 4G overlap.

[0236] In this case, on the irradiation surface 250, the light from the light-emitting section Emn of the light source 4E with the same numbers m and n, the light from the light-emitting section Fmn of the light source 4F, and the light from the light-emitting section Gmn of the light source 4F are irradiated onto the same range on the irradiation surface 250. Hereinafter, on the irradiation surface 250, the range where the light from the light-emitting section Emn of the light source 4E, the light from the light-emitting section Fmn of the light source 4F, and the light from the light-emitting section Gmn of the light source 4F are irradiated is denoted as the section Smn. Incidentally, the irradiation surface 250 is divided into a total of 24 sections Smn, six in the x direction and four in the y direction.

[0237] Moreover, although not shown in the drawings, similar to the first and second embodiments, the light-emitting section 4 of the present embodiment irradiates light on the irradiation surface at a distance different from the reference distance L2 from the light-emitting section 4 (for example, the distance L1) such that the irradiation range 100E based on the light source 4E, the irradiation range 100F based on the light source 4F, and the irradiation range 100G based on the light source 4G are arranged in a staggered manner in a direction intersecting the z direction (for example, the y direction).

[0238] In this case, if the light-emitting sections Emn of the light source 4E, the light-emitting sections Fmn of the light source 4F, and the light-emitting sections Gmn of the light source 4G given the same numbers are simultaneously set to the lit state, similar to the case of the second embodiment, it becomes difficult to divide the irradiation surface into a plurality of sections and irradiate light on adjacent sections at different times.

[0239] Therefore, the light-emitting drive section 6 of the present embodiment sets one of the light-emitting sections Emn of the light source 4E, the light-emitting sections Fmn of the light source 4F, and the light-emitting sections Gmn of the light source 4G given the same numbers to the lit state and sets the remaining two to the extinguished state, rather than simultaneously setting the light-emitting sections Emn of the light source 4E, the light-emitting sections Fmn of the light source 4F, and the light-emitting sections Gmn of the light source 4G given the same numbers to the lit state.

[0240] More specifically, at the time when the light-emitting drive section 6 causes the first group to emit light, it sets one of the light-emitting sections Emn of the light source 4E, the light-emitting sections Fmn of the light source 4F, and the light-emitting sections Gmn of the light source 4G belonging to the first group to the lit state and sets the remaining two to the extinguished state.

[0241] In addition, at the time when the light-emitting drive section 6 causes the first group to emit light, it sets the light-emitting sections Emn of the light source 4E, the light-emitting sections Fmn of the light source 4F, and the light-emitting sections Gmn of the light source 4G belonging to the second group and the third group to the extinguished state.

[0242] Moreover, when the light emission driving unit 6 causes the second group to emit light after causing the first group to emit light, one of the light emission regions Emn of the light source 4E belonging to the second group, the light emission region Fmn of the light source 4F, and the light emission region Gmn of the light source 4G is set to the lit state, and the remaining two are set to the extinguished state.

[0243] In addition, when the light emission driving unit 6 causes the second group to emit light, the light emission regions Emn of the light source 4E belonging to the first group and the third group, the light emission region Fmn of the light source 4F, and the light emission region Gmn of the light source 4G are set to the extinguished state.

[0244] Furthermore, when the light emission driving unit 6 causes the third group to emit light after causing the first group and the second group to emit light, one of the light emission regions Emn of the light source 4E belonging to the third group, the light emission region Fmn of the light source 4F, and the light emission region Gmn of the light source 4G is set to the lit state, and the remaining two are set to the extinguished state.

[0245] In addition, when the light emission driving unit 6 causes the third group to emit light, the light emission regions Emn of the light source 4E belonging to the first group and the second group, the light emission region Fmn of the light source 4F, and the light emission region Gmn of the light source 4G are set to the extinguished state.

[0246] Here, in the present embodiment, when the light emission driving unit 6 causes each group to emit light, the light emission driving unit 6 drives the light emitting unit 4 in such a manner that the light emission regions of the light sources belonging to each group are brought into the lit state and the extinguished state according to the following criteria.

[0247] That is, the light emission driving unit 6 drives the light emitting unit 4 in such a manner that the light emission regions of the light sources having a small influence on the light emission of the next group due to the heat generated by the light emission of the previous group are brought into the lit state, and the light emission regions of the light sources having a large influence are brought into the extinguished state.

[0248] Specifically, for example, when the light emission driving unit 6 causes the first group to emit light, the light emission driving unit 6 controls the light emitting unit 4 in such a manner that the light emission regions E11, E12, E13, E14, E41, E42, E43, E44 of the light source 4E among the light sources 4E, 4F, 4G are brought into the lit state, and the light emission regions F11, F12, F13, F14, F41, F42, F43, F44 of the light source 4F and the light emission regions G11, G12, G13, G14, G41, G42, G43, G44 of the light source 4G are brought into the extinguished state.

[0249] In this case, in the light source 4E, heat is generated due to the light emission of the light emission regions E11, E12, E13, E14, E41, E42, E43, E44 that are brought into the lit state.

[0250] Next, at the moment when the light emission driving unit 6 causes the second group to emit light after causing the first group to emit light, the light emission driving unit 6 controls the light emitting unit 4 in such a manner that any one of the light emission regions F21, F22, F23, F24, F51, F52, F53, F54 of the light source 4F or the light emission regions G21, G22, G23, G24, G51, G52, G53, G54 of the light source 4G, which are less affected by the heat generated by the light emission of the light emission regions E11, E12, E13, E14, E41, E42, E43, E44 of the light source 4E accompanying the first group, becomes a lit state.

[0251] In this example, at the moment when the light emission driving unit 6 causes the second group to emit light, the light emission driving unit 6 controls the light emitting unit 4 in such a manner that the light emission regions F21, F22, F23, F24, F51, F52, F53, F54 of the light source 4F become a lit state while the light emission regions E21, E22, E23, E24, E51, E52, E53, E54 of the light source 4E and the light emission regions G21, G22, G23, G24, G51, G52, G53, G54 of the light source 4G become an extinguished state.

[0252] In this case, in the light source 4F, heat is generated by the light emission of the light emission regions F21, F22, F23, F24, F51, F52, F53, F54 that become a lit state.

[0253] Next, at the moment when the light emission driving unit 6 causes the third group to emit light after causing the first group and the second group to emit light, the light emission driving unit 6 controls the light emitting unit 4 in such a manner that any one of the light emission regions G31, G32, G33, G34, G61, G62, G63, G64 of the light source 4G, which are less affected by the heat generated by the light emission of the light emission regions E11, E12, E13, E14, E41, E42, E43, E44 of the light source 4E accompanying the first group and the light emission regions F21, F22, F23, F24, F51, F52, F53, F54 of the light source 4F accompanying the second group, becomes a lit state.

[0254] Incidentally, at the moment when the light emission driving unit 6 causes the third group to emit light, the light emission driving unit 6 controls the light emitting unit 4 in such a manner that the light emission regions G31, G32, G33, G34, G61, G62, G63, G64 of the light source 4G become a lit state while the light emission regions E31, E32, E33, E34, E61, E62, E63, E64 of the light source 4E and the light emission regions F31, F32, F33, F34, F61, F62, F63, F64 of the light source 4F become an extinguished state.

[0255] As described in Embodiment 1, sometimes when the light-emitting partition of the light source is set to the lit state, heat is generated along with the light emission of the VCSEL. Moreover, due to the heat generated along with the light emission of the VCSEL, the temperature of the lit light-emitting partition or the light-emitting partition adjacent to the lit light-emitting partition rises. And sometimes when the temperature of the light-emitting partition rises, it affects the light-emitting efficiency of the VCSEL when the light-emitting partition is set to the lit state.

[0256] The light-emitting drive unit 6 of the present embodiment sets the light-emitting partition of the light source with less influence of the heat generated along with the light emission of the previous group on the light emission of the next group to the lit state and sets the light-emitting partition of the light source with greater influence to the extinguished state. For example, compared with the case of a light source fixed to the lit state and the extinguished state, the influence of the heat generated along with the light emission on the light-emitting efficiency is suppressed.

[0257] In the above Embodiment 1 and Embodiment 2, the distance at which the irradiation ranges of two light sources substantially completely overlap on the irradiation surface is set as the reference distance. When an object exists at a distance closer than the reference distance, one light source is set to the lit state and the other light source is set to the extinguished state. However, the reference distance is not limited to this, and the distance to be set as the reference distance can be set according to the required accuracy, etc. For example, even when an object exists at a distance where the ratio of the overlapping portion of the irradiation ranges of multiple light sources on the irradiation surface is less than 50%, when the requirement for ranging accuracy is not high, both can be set to the lit state instead of setting one light source to the lit state and the other light source to the extinguished state. And setting one light source to the lit state and the other light source to the extinguished state or setting multiple light sources to the lit state simultaneously can be switched not only according to the required distance but also according to the accuracy.

[0258] And, as in Embodiment 2, when the irradiation surface is divided into multiple partitions to irradiate light, in the above example, it is assumed that the light-emitting partition Ci of the light source 4C and the light-emitting partition Di of the light source 4D with the same number are not set to the lit state simultaneously, but it is not limited to this.

[0259] As long as the light can be irradiated to the multiple partitions of the irradiation surface in a divided manner, the light-emitting partition Ci of the light source 4C and the light-emitting partition Di of the light source 4D with the same number can be set to the lit state simultaneously.

[0260] For example, as Figure 9As shown in (a), when the light-emitting partition D1 of the light source 4D is set to the lighting state, a part of the area of ​​the irradiated partition Q1 irradiated by the light from the light-emitting partition D1 overlaps with the irradiated partition P5, but there is a non-irradiated area in the irradiated partition P5 that is not irradiated by the light from the light-emitting partition D1. Therefore, even when the light-emitting partitions C1, C3, C6, C8, C9, C11 of the light source 4C and the light-emitting partitions D1, D3, D6, D8, D9, D11 of the light source 4D are set to the lighting state at the same time, the split irradiation of the irradiated area irradiated by the light from these light-emitting partitions and the non-irradiated area that is not irradiated by the light can be barely achieved. In this case, the distance that can barely achieve split irradiation can be set as the reference distance, and the light-emitting partition Ci of the light source 4C and the light-emitting partition Di of the light source 4D with the same number are set to the lighting state at the same time.

[0261] On the other hand, Figure 9 Compared with the example shown in (a), the area where the irradiation partitions Pi and the irradiation partitions Qi of the same number i do not overlap becomes larger, and when the luminous partitions C1, C3, C6, C8, C9, C11 of the light source 4C and the luminous partitions D1, D3, D6, D8, D9, D11 of the light source 4D are set to the lighting state at the same time, it will result in that the divided irradiation cannot be performed at the distance of the irradiation light to the entire irradiation surface 240. In this case, it is sufficient to set one of the luminous partitions Ci of the light source 4C and the luminous partitions Di of the light source 4D of the same number to the extinguished state.

[0262] [Implementation Method 4]

[0263] Next, Embodiment 4 of the present invention will be described. The configurations of the light emitting unit 4 and the light receiving unit 5 of the optical device 3 of the distance measuring device 1 of Embodiment 4 are different from those of Embodiments 1 to 3. In Embodiment 4, the same reference numerals are used for the same configurations as Embodiments 1 to 3, and detailed descriptions thereof are omitted.

[0264] (Light emitting unit 4)

[0265] Figure 14 The diagram shows light sources 4H and 4I included in the light emitting unit 4 according to the fourth embodiment and irradiation ranges 100H and 100I which are ranges irradiated by light emitted from the light sources 4H and 4I.

[0266] exist Figure 14 , the front side of the paper is set as the +x direction, the upper direction of the paper is set as the +y direction, the right direction of the paper is set as the +z direction, and the opposite directions are set as -x, -y, and -z directions.

[0267] The light emitting unit 4 includes a light source 4H that irradiates light to the irradiation range 100H and a light source 4I that irradiates light to an irradiation range 100I different from the irradiation range 100H. The light emitting unit 4 irradiates light at a certain distance (reference distance L4 described later) in the direction (+z direction) in which the light sources 4H and 4I emit light, such that the irradiation range 100H and the irradiation range 100I are juxtaposed. In this example, the light source 4H is an example of the first light source, the light source 4I is an example of the second light source, the irradiation range 100H is an example of the first irradiation range, and the irradiation range 100I is an example of the second irradiation range.

[0268] In the light emitting unit 4 of the present embodiment, the light sources 4H and 4I are arranged juxtaposed along the y direction. In this example, the light source 4H is arranged on the +y direction side with respect to the light source 4I.

[0269] Figure 15 FIG. is a diagram for explaining the structures of the light sources 4H and 4I included in the light emitting unit 4 of Embodiment 4. In Figure 15 this figure, the right direction of the paper surface is set as the +x direction, the upper direction of the paper surface is set as the +y direction, the inside direction of the paper surface is set as the +z direction, and the opposite directions are set as the -x, -y, and -z directions, respectively. Figure 15 FIG. is a view of the light sources 4H and 4I of the light emitting unit 4 emitting light as observed from the side opposite to the side from which the light emitting unit 4 emits light.

[0270] The light sources 4H and 4I of the present embodiment each have light emitting surfaces 48 and 49 on which a plurality of VCSELs are arranged. In this example, the light emitting surface 48 of the light source 4H is juxtaposed on the +y direction side with respect to the light emitting surface 49 of the light source 4I.

[0271] The light emitting surface 48 of the light source 4H and the light emitting surface 49 of the light source 4I are each divided into a plurality of light emitting partitions each including at least one VCSEL. As an example, the light emitting surface 48 of the light source 4H is divided into a total of six light emitting partitions H1 to H6, three in the x direction and two in the y direction. In this example, the light emitting partitions H1 to H6 are sequentially located from the upper left corner (-x direction side and +y direction side end) to the lower right corner (+x direction side and -y direction side end) of the light emitting surface 48. Similarly, as an example, the light emitting surface 49 of the light source 4I is divided into a total of six light emitting partitions I1 to I6, three in the x direction and two in the y direction. In this example, the light emitting partitions I1 to I6 are sequentially located from the upper left corner (-x direction side and +y direction side end) to the lower right corner (+x direction side and -y direction side end) of the light emitting surface 49.

[0272] Incidentally, in the light emitting unit 4 of the present embodiment, the light emitting partitions H4, H5, and H6 on the light emitting surface 48 of the light source 4H are adjacent to the light emitting partitions I1, I2, and I3 on the light emitting surface 49 of the light source 4I in the y direction.

[0273] Each light-emitting section H1 to H6 of the light source 4H and each light-emitting section I1 to I6 of the light source 4I are independently driven by a light-emitting driving unit 6 (see Figure 1 ) to emit light. The light-emitting driving unit 6 drives each light-emitting section of the light sources 4H and 4I according to a control signal from a control unit 8 (see Figure 1 ). Therefore, each light-emitting section H1 to H6 of the light source 4H and each light-emitting section I1 to I6 of the light source 4I do not necessarily all emit light simultaneously, and a state in which a part thereof emits light and the remaining part does not emit light can be adopted. In the present embodiment, a state in which each light-emitting section H1 to H6 of the light source 4H and each light-emitting section I1 to I6 of the light source 4I are in a light-emitting state is referred to as a state in which the light-emitting section is in a lit state. Further, a state in which each light-emitting section H1 to H6 of the light source 4H and each light-emitting section I1 to I6 of the light source 4I are in a non-light-emitting state is referred to as a state in which the light-emitting section is in an extinguished state.

[0274] In Figure 14 , irradiation surfaces 260 and 270 irradiated with light in an irradiation range 100H and an irradiation range 100I, which are orthogonal to the +z direction, are shown at a certain distance in the direction of light emission (+z direction) of the light sources 4H and 4I. The irradiation surfaces 260 and 270 spread in the x direction and the y direction at a certain distance in the +z direction. Further, the irradiation surfaces 260 and 270 are arranged in the +z direction in order from the light sources 4H and 4I. Hereinafter, the distance in the +z direction from the light sources 4H and 4I to the irradiation surface 260 is denoted as a distance L3, and the distance in the +z direction from the light sources 4H and 4I to the irradiation surface 270 is denoted as a distance L4.

[0275] The light rays emitted from the light sources 4H and 4I are refracted by an optical system (not shown) provided in the light sources 4H and 4I, and spread and irradiate on a surface perpendicular to the emission direction.

[0276] When viewed from the +x direction side, in the present embodiment, the light-emitting unit 4 irradiates light in such a manner that the irradiation range 100H intersects the irradiation range 100I at a certain distance L5 in the +z direction.

[0277] In this case, as shown in Figure 14 , in a region where the distance in the +z direction from the light sources 4H and 4I is less than the distance L5, the irradiation range 100H is located on the +y direction side with respect to the irradiation range 100I. Further, in a region where the distance in the +z direction from the light sources 4H and 4I exceeds the distance L5, the irradiation range 100H is located on the -y direction side with respect to the irradiation range 100I.

[0278] In the distance measuring device 1 of the present embodiment, the light from the light sources 4H and 4I irradiates an object existing within a range where the distance in the +z direction from the light-emitting unit 4 exceeds the distance L5.

[0279] Figure 16 In Figure 16 of (a) to Figure 16 (b) are diagrams for explaining the irradiation surfaces 260 and 270. Figure 16 (a) of shows the irradiation surface 270 at a distance L4 in the +z direction from the light-emitting part 4. And, Figure 16 (b) of shows the irradiation surface 260 at a distance L3 closer than the distance L4 in the +z direction from the light-emitting part 4. In Figure 16 of (a) to Figure 16 (b), the right direction of the paper surface is set as the +x direction, the upper direction of the paper surface is set as the +y direction, the inside of the paper surface is set as the +z direction, and the opposite directions are set as the -x, -y, and -z directions respectively.

[0280] As Figure 16 of (a) to Figure 16 (b) shows, on the irradiation surfaces 260 and 270, the irradiation range 100H includes the irradiation sub-regions T1 to T6 irradiated by the light emitted from the light-emitting sub-regions H1 to H6 of the light source 4H. The irradiation sub-regions T1 to T6 are sequentially located from the lower right corner (+x direction side and -y direction side end) to the upper left corner (-x direction side and +y direction side end) of the irradiation range 100H. In the present embodiment, the arrangement of the irradiation sub-regions T1 to T6 within the irradiation range 100H is reversed in the x direction and the y direction with respect to the arrangement of the light-emitting sub-regions H1 to H6 on the light-emitting surface 48 of the light source 4H.

[0281] Similarly, on the irradiation surfaces 260 and 270, the irradiation range 100I includes the irradiation sub-regions U1 to U6 irradiated by the light emitted from the light-emitting sub-regions I1 to I6 of the light source 4I. The irradiation sub-regions U1 to U6 are sequentially located from the lower right corner (+x direction side and -y direction side end) to the upper left corner (-x direction side and +y direction side end) of the irradiation range 100I. In the present embodiment, the arrangement of the irradiation sub-regions U1 to U6 within the irradiation range 100I is reversed in the x direction and the y direction with respect to the arrangement of the light-emitting sub-regions I1 to I6 on the light-emitting surface 49 of the light source 4I.

[0282] As Figure 16 (a) shows, on the irradiation surface 270 at a distance L4 in the +z direction from the light-emitting part 4, the irradiation range 100H based on the light source 4H and the irradiation range 100I based on the light source 4I are juxtaposed in the y direction. Incidentally, on the irradiation surface 270, the irradiation range 100H and the irradiation range 100I do not overlap.

[0283] In the present embodiment, the distance L4 at which the irradiation range 100H and the irradiation range 100I are juxtaposed on the irradiation surface 270 is an example of the reference distance. Hereinafter, it is sometimes denoted as the reference distance L4.

[0284] And, as shown in (b) of Figure 16 , on the irradiation surface 260 at a distance L3 closer to the +z direction from the light-emitting unit 4 than the reference distance L4, a partial area of the irradiation range 100H based on the light source 4H overlaps with a partial area of the irradiation range 100I based on the light source 4I. Incidentally, in the present embodiment, when the distance in the +z direction from the light-emitting unit 4 is closer than the reference distance L4, a deviation occurs in the positional relationship between the irradiation ranges 100H and 100I juxtaposed at the reference distance L4, and a partial area of the irradiation range 100H overlaps with a partial area of the irradiation range 100I.

[0285] On the irradiation surface 260, the irradiation sub-regions T4 to T6 of the irradiation range 100H and the irradiation sub-regions U1 to U3 of the irradiation range 100I adjacent to the irradiation sub-regions T4 to T6 in the +y direction overlap with each other. More specifically, on the irradiation surface 260, a partial area on the +y direction side of the irradiation sub-regions T4 to T6 of the irradiation range 100H overlaps with a partial area on the -y direction side of the irradiation sub-regions U1 to U3 of the irradiation range 100I.

[0286] (Light receiving unit 5)

[0287] Although not shown in the figure, the light receiving unit 5 of the fourth embodiment (refer to Figure 1 ) has a light receiving surface on which a plurality of light receiving elements are arranged. The light receiving surface is divided into a plurality of light receiving sub-regions corresponding to the irradiation sub-regions T1 to T6 and the irradiation sub-regions U1 to U6. Specifically, the light receiving surface is divided into a total of 12 light receiving sub-regions, three in the x direction and four in the y direction.

[0288] Each light receiving sub-region receives light emitted from the light emitting sub-regions H1 to H6 of the light source 4H and the light emitting sub-regions I1 to I6 of the light source 4I and reflected by an object present in the irradiation sub-regions T1 to T6 and the irradiation sub-regions U1 to U6. Each light receiving sub-region is independently driven by a light receiving drive unit 7 (refer to Figure 1 ) to perform a light receiving operation.

[0289] Thereby, the light receiving unit 5 of the present embodiment can obtain a light receiving result for each of the irradiation sub-regions T1 to T6 and each of the irradiation sub-regions U1 to U6.

[0290] (Drive control of the light-emitting unit 4)

[0291] Next, the driving of the light-emitting unit 4 performed by the light-emitting drive unit 6 according to the control of the control unit 8 will be described.

[0292] When the light-emitting drive unit 6 of the present embodiment irradiates the irradiation surface 260 at a distance L3 in the +z direction from the light-emitting unit 4, which is closer than the reference distance L4, the light-emitting unit 4 is driven such that the light-emitting regions that emit light toward the irradiation sub-regions adjacent between the irradiation range 100H and the irradiation range 100I emit light at different times.

[0293] Specifically, the light-emitting drive unit 6 causes the light-emitting region H4 of the light source 4H that emits light toward the irradiation sub-region T4 and the light-emitting region I1 of the light source 4I that emits light toward the irradiation sub-region U1 adjacent to the irradiation sub-region T4 to emit light at different times. Further, the light-emitting drive unit 6 causes the light-emitting region H5 of the light source 4H that emits light toward the irradiation sub-region T5 and the light-emitting region I2 of the light source 4I that emits light toward the irradiation sub-region U2 adjacent to the irradiation sub-region T5 to emit light at different times. Moreover, the light-emitting drive unit 6 causes the light-emitting region H6 of the light source 4H that emits light toward the irradiation sub-region T6 and the light-emitting region I3 of the light source 4I that emits light toward the irradiation sub-region U3 adjacent to the irradiation sub-region T6 to emit light at different times.

[0294] Here, when irradiating the irradiation surface 260 with light, if the light-emitting region H4 of the light source 4H and the light-emitting region I1 of the light source 4I emit light at the same time, then in the irradiation sub-region T4 of the irradiation surface 260, there are a region where the light from the light-emitting region H4 is irradiated and the light from the light-emitting region I1 is not irradiated, and a region where the light from the light-emitting region H4 and the light from the light-emitting region I1 are overlapped and irradiated. As a result, the amount of light irradiated to the irradiation sub-region T4 becomes uneven.

[0295] Similarly, if the light-emitting region H4 of the light source 4H and the light-emitting region I1 of the light source 4I emit light at the same time, then in the irradiation sub-region U1 of the irradiation surface 260, there are a region where the light from the light-emitting region I1 is irradiated and the light from the light-emitting region H4 is not irradiated, and a region where the light from the light-emitting region H4 and the light from the light-emitting region I1 are overlapped and irradiated. As a result, the amount of light irradiated to the irradiation sub-region U1 becomes uneven.

[0296] In this case, on the irradiation surface 260, if there is an object in the irradiation sub-region T4 or the irradiation sub-region U1, it may sometimes be impossible to accurately measure the distance to the object.

[0297] In addition, although detailed description is omitted, if the light-emitting regions H5, H6 of the light source 4H and the light-emitting regions I2, I3 of the light source 4I emit light at the same time, then similarly, in the irradiation sub-regions T5, T6, U2, U3 of the irradiation surface 260, the amount of light irradiated also becomes uneven. In this case, it may sometimes be impossible to accurately measure the distance to the object.

[0298] In contrast, in the present embodiment, when light is irradiated onto the irradiation surface 260 at a distance L3 that is closer than the reference distance L4 in the +z direction from the light emitting unit 4, by causing the light emitting partitions that emit light toward the irradiation partitions adjacent between the irradiation range 100H and the irradiation range 100I to emit light at different times, in the irradiation partitions, the light from the light emitting partitions of the light source 4H and the light from the light emitting partitions of the light source 4I are suppressed from overlapping and irradiating. Thereby, the unevenness of the amount of light irradiated onto the irradiation partitions is suppressed.

[0299] Here, the light emission driving unit 6 can drive the light emitting unit 4 in such a manner that the light emitting partitions that emit light toward the irradiation partitions adjacent between the irradiation range 100H and the irradiation range 100I emit light at the same time when light is irradiated onto the irradiation surface 270 at a distance equal to the reference distance L4 in the +z direction from the light emitting unit 4.

[0300] As described above, on the irradiation surface 270 at a distance equal to the reference distance L4 in the +z direction from the light emitting unit 4, the irradiation partitions adjacent between the irradiation range 100H and the irradiation range 100I do not overlap each other. Thereby, in each of the irradiation partitions adjacent between the irradiation range 100H and the irradiation range 100I, the amount of light irradiated from the light emitting unit 4 becomes uniform.

[0301] In this case, it is not easy to generate the influence caused by the unevenness of the amount of light irradiated onto the irradiation partitions such as the irradiation surface 260.

[0302] The embodiments of the present invention have been described above, but the technical scope of the present invention is not limited to the scope described in the foregoing embodiments. From the description of the scope of the technical solution, the embodiments obtained by making various changes or improvements to the above embodiments are also included in the technical scope of the present invention.

[0303] <Supplementary Note>

[0304] (1) A light emitting device, characterized by comprising: a light emitting unit having a first light source that irradiates a first irradiation range and a second light source that irradiates a second irradiation range in a lit state, and irradiating the first irradiation range and the second irradiation range side by side or overlapping at a reference distance; and a driving unit that drives the light emitting unit in such a manner that one of the first light source and the second light source is in a lit state and the other is in an extinguished state when irradiating an object at a first distance different from the reference distance through the light emitting unit.

[0305] (2) The light emitting device according to (1), characterized in that

[0306] the first light source includes a plurality of light emitting partitions that respectively emit light toward a plurality of irradiation partitions obtained by dividing the first irradiation range,

[0307] The second light source includes a plurality of light-emitting sections that respectively emit light toward a plurality of irradiation sections obtained by dividing the second irradiation range.

[0308] The driving unit drives the light-emitting unit in the first light source and the second light source respectively so that the light-emitting sections that emit light toward adjacent irradiation sections emit light at different times.

[0309] (3) The light-emitting device according to (2), wherein

[0310] The first light source has a first light-emitting section that irradiates a first irradiation section and a third light-emitting section that irradiates a third irradiation section adjacent to the first irradiation section.

[0311] The second light source has a second light-emitting section that irradiates a second irradiation section and a fourth light-emitting section that irradiates a fourth irradiation section adjacent to the second irradiation section.

[0312] At the reference distance, the first irradiation section and the second irradiation section overlap, and the third irradiation section and the fourth irradiation section overlap.

[0313] The driving unit drives the light-emitting unit at the first distance where the first irradiation section and the fourth irradiation section overlap so that one of them is in the lit state and the other is in the extinguished state.

[0314] (4) The light-emitting device according to any one of (1) to (3), wherein

[0315] Based on the lighting history of the first light source and the second light source, it is set which one is in the lit state and which one is in the extinguished state.

[0316] (5) The light-emitting device according to (4), wherein

[0317] When irradiating an object at the first distance, the driving unit drives the light-emitting unit so that the one with a shorter total lighting time among the first light source and the second light source is in the lit state and the other with a longer total lighting time is in the extinguished state.

[0318] (6) The light-emitting device according to (4), wherein

[0319] The first light source and the second light source each have a plurality of light-emitting sections that emit light toward the first irradiation range and the second irradiation range, and are driven so that each group including at least one light-emitting section emits light at different times.

[0320] When irradiating an object at the first distance, the driving unit drives the light-emitting unit in such a manner that one of the lights generated by the light emission of the previous group having a small influence on the light emission of the next group is in the lit state and the other having a large influence is in the extinguished state.

[0321] (7) The light-emitting device according to any one of (1) to (6), characterized in that

[0322] When an object is detected at the first distance, the driving unit drives the light-emitting unit in such a manner that one of the first light source and the second light source is in the lit state and the other is in the extinguished state.

[0323] (8) The light-emitting device according to any one of (1) to (7), characterized in that

[0324] The first irradiation range and the second irradiation range overlap at the reference distance,

[0325] The first distance is closer than the reference distance.

[0326] (9) A light-emitting device, characterized by comprising:

[0327] A light-emitting unit having a first light source that irradiates a first irradiation range in a lit state and a second light source that irradiates a second irradiation range, and irradiating the first irradiation range and the second irradiation range side by side or overlapping at a reference distance; and

[0328] A driving unit capable of switching between a first mode for irradiating an object at a first distance different from the reference distance and a second mode for irradiating an object at a distance farther than the first distance by the light-emitting unit, and driving the light-emitting unit in the first mode in such a manner that one of the first light source and the second light source is in the lit state and the other is in the extinguished state, and driving the light-emitting unit in the second mode in such a manner that both the first light source and the second light source are in the lit state.

[0329] (10) The light-emitting device according to (9), characterized in that

[0330] When it is predicted that an object will reach the first distance, the driving unit drives the light-emitting unit through the first mode.

[0331] (11) A distance measuring device, characterized by comprising:

[0332] (1) to (10) The light-emitting device according to any one of;

[0333] A light-receiving unit that receives light irradiated from the light-emitting device and reflected by an object; and

[0334] A calculation unit that calculates the distance to the object based on the light reception result in the light reception unit.

[0335] (12) The distance measuring device according to (11), characterized in that

[0336] When an object is detected at the first distance or it is predicted that the object will reach the first distance based on the light reception result in the light reception unit or the calculation result in the calculation unit, the drive unit drives the light emitting unit in such a way that one of the first light source and the second light source is in the lit state and the other is in the extinguished state.

[0337] Compared with the case where all light sources are lit regardless of the distance, the light emitting device according to (1) can suppress the influence caused by the deviation of the irradiation range of each light source.

[0338] Compared with the case where all light sources are lit regardless of the distance, the light emitting device according to (2) can suppress the interference to adjacent irradiation zones.

[0339] Even under conditions where interference is likely to occur due to the overlap of the irradiation ranges of each other, the light emitting device according to (3) can suppress the interference to adjacent irradiation zones.

[0340] Compared with the case where the light sources are fixed in the lit state and the extinguished state, the light emitting device according to (4) can perform drive control corresponding to the lighting conditions of each light source.

[0341] Compared with the case where the light sources are fixed in the lit state and the extinguished state, the light emitting device according to (5) suppresses the deviation of the total lighting time of each light source.

[0342] Compared with the case where the light sources are fixed in the lit state and the extinguished state, the light emitting device according to (6) suppresses the influence of the heat generated by the light emission on the light emission efficiency.

[0343] The light emitting device according to (7) suppresses the irradiation of an object existing at the first distance in a state where the irradiation ranges of each light source deviate.

[0344] The light emitting device according to (8) suppresses the unevenness of the light amount irradiated in the overlapping part and the non - overlapping part on the side closer to the light emitting part where the light amount irradiated is more than on the side farther from the light emitting part, and suppresses the excessive light amount irradiated to the object.

[0345] Compared with the case where all light sources are lit regardless of the distance, the light emitting device according to (9) can suppress the influence caused by the deviation of the irradiation range of each light source.

[0346] With respect to the light-emitting device according to (10), irradiation of an object that has reached the first distance is suppressed in a state where the irradiation ranges of the respective light sources are shifted.

[0347] With respect to the distance measurement device according to (11), compared with a case where all light sources are lit regardless of the distance, the influence caused by the shift of the irradiation ranges of the respective light sources can be suppressed.

[0348] With respect to the distance measurement device according to (12), detection of an object can be performed without setting a separate sensor, and it can be used for control.

[0349] The above-described embodiments of the present invention are provided for the purpose of illustration and explanation. In addition, the embodiments of the present invention do not comprehensively and exhaustively include the present invention, and do not limit the present invention to the disclosed manner. Obviously, various modifications and changes are self-evident to those skilled in the art to which the present invention pertains. This embodiment is selected and described in order to most easily understand the principle of the present invention and its application. Thus, other technicians in this technical field can understand the present invention through various modification examples that are optimized for specific uses assumed to be various embodiments. The scope of the present invention is defined by the above claims and their equivalents.

Claims

1. A light emitting device, characterized in that: have: a light emitting unit having a first light source for illuminating a first irradiation range and a second light source for illuminating a second irradiation range in a lit state, and illuminating the first irradiation range and the second irradiation range in parallel or overlapping with each other at a reference distance; and The driving unit drives the light emitting unit so that one of the first light source and the second light source is turned on and the other is turned off when irradiating an object at a first distance different from the reference distance through the light emitting unit.

2. The light emitting device according to claim 1, characterized in that: The first light source includes a plurality of light emitting subareas that emit light toward a plurality of irradiation subareas that are obtained by dividing the first irradiation range. The second light source includes a plurality of light emitting subareas that emit light toward a plurality of irradiation subareas that are obtained by dividing the second irradiation range. The driving section drives the light emitting portion in each of the first light source and the second light source so that the light emitting sub-areas emitting light toward the mutually adjacent irradiation sub-areas emit light at different timings.

3. The light emitting device according to claim 2, characterized in that: The first light source has a first light emitting subarea for illuminating the first illuminating subarea and a third light emitting subarea for illuminating a third illuminating subarea adjacent to the first illuminating subarea. The second light source has a second light emitting subarea for illuminating the second illuminating subarea and a fourth light emitting subarea for illuminating the fourth illuminating subarea adjacent to the second illuminating subarea. At the reference distance, the first irradiation sub-area overlaps with the second irradiation sub-area, and the third irradiation sub-area overlaps with the fourth irradiation sub-area, The driving unit drives the light emitting unit so that one of the first irradiation section and the fourth irradiation section is turned on and the other is turned off at the first distance where the first irradiation section and the fourth irradiation section overlap.

4. The light emitting device according to any one of claims 1 to 3, characterized in that: Which one is to be in the lighting state and which one is to be in the extinguished state is set based on the lighting history of the first light source and the second light source.

5. The light emitting device according to claim 4, characterized in that: When irradiating the object at the first distance, the driving unit drives the light emitting unit so that one of the first light source and the second light source having a shorter total lighting time is in a lighting state and the other having a longer total lighting time is in an extinguished state.

6. The light emitting device according to claim 4, characterized in that: The first light source and the second light source each have a plurality of light-emitting subareas that emit light toward the first irradiation range and the second irradiation range, and are driven so that each group including at least one light-emitting subarea emits light at different times. When irradiating the object at the first distance, the driving unit drives the light emitting units so that the one having less influence due to heat generated by light emission of the previous group on light emission of the next group becomes lit and the other having greater influence becomes extinguished.

7. The light emitting device according to any one of claims 1 to 6, characterized in that: When an object is detected at the first distance, the driving unit drives the light emitting unit so that one of the first light source and the second light source is turned on and the other is turned off.

8. The light emitting device according to any one of claims 1 to 7, characterized in that: The first irradiation range and the second irradiation range overlap at the reference distance, The first distance is closer than the reference distance.

9. A light emitting device, characterized in that: have: a light emitting unit having a first light source for illuminating a first irradiation range and a second light source for illuminating a second irradiation range in a lit state, and illuminating the first irradiation range and the second irradiation range in parallel or overlapping with each other at a reference distance; and A driving unit capable of switching to drive the light emitting unit between a first mode in which the light emitting unit is used to illuminate an object at a first distance different from the reference distance and a second mode in which the light emitting unit is used to illuminate an object at a distance longer than the first distance, wherein in the first mode, the light emitting unit is driven in such a manner that one of the first light source and the second light source is turned on and the other is turned off, and in the second mode, the light emitting unit is driven in such a manner that both the first light source and the second light source are turned on.

10. The light emitting device according to claim 9, characterized in that: When the arrival of the object at the first distance is predicted, the driving unit drives the light emitting unit in the first mode.

11. A distance measuring device, characterized in that: have: The light emitting device according to any one of claims 1 to 10; a light receiving unit that receives light emitted from the light emitting device and reflected by an object; and The calculation unit calculates the distance to the object based on the light reception result in the light receiving unit.

12. The distance measuring device according to claim 11, characterized in that: When an object is detected at the first distance or the arrival of the object at the first distance is predicted based on the light reception result in the light receiving unit or the calculation result in the calculation unit, the driving unit drives the light emitting unit in such a manner that one of the first light source and the second light source is turned on and the other is turned off.

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