Crew monitoring camera

Abstract

This disclosure aims to provide an occupant monitoring camera capable of preventing stray light from reaching the lens regardless of the camera's field of view. [Solution] The occupant monitoring camera according to this disclosure comprises a camera for imaging the occupants of a vehicle, a light source for illuminating the occupants with light, a light-shielding member provided around the lens of the camera for blocking light incident from the outside, and a cover provided between the camera and the occupants, wherein the shape of the surface of the light-shielding member facing the cover is saw-toothed.

Description

【Technical Field】 【0004】 , , , , , , , , 【0005】 , , , , 【0001】 The present disclosure relates to an occupant monitoring camera for monitoring an occupant of a vehicle. 【Background Art】 【0002】 When the lens of the camera included in the occupant monitoring camera is visible to the occupant of the vehicle, the occupant may feel discomfort and a sense of oppression from the feeling of being monitored by the camera. The occupant visually recognizes the camera when the light reflected by the lens of the camera enters the eyes, and in order to suppress this, it is generally practiced to dispose a shielding member using a material that absorbs and attenuates visible light between the lens of the camera and the occupant. However, when the wavelength captured by the camera is in the near-infrared region or the visible region, the light reflected inside the housing of the occupant monitoring camera may reach the occupant, and the occupant may be able to visually recognize the camera. In particular, the barrel-shaped light shielding member disposed around the lens is likely to generate stray light. 【0003】 Conventionally, in a small camera module such as a smartphone, a technique has been disclosed for preventing the generation of stray light reaching the lens by providing a stepped structure in the barrel disposed around the lens (see, for example, Patent Document 1). 【Prior Art Documents】 【Patent Documents】​​​​​​​​​​​​​​​​​Patent Document 1 describes a stepped structure in the barrel, the purpose of which is to perform a texturing process on the inner wall of the barrel. Furthermore, the stepped structure includes a rounded stepped surface on the inner wall of the barrel to improve the ease of mold making. The purpose of providing a rounded stepped surface is to avoid creating sharp protrusions on the mold and to improve the ease of texturing. 【0006】 However, in Patent Document 1, the barrel length decreases inversely proportional to the increase in the camera's field of view. Therefore, when using a wide-angle lens, the step difference is almost eliminated, making it impossible to secure a stepped surface, which presents a problem in that it becomes difficult to prevent stray light from reaching the lens. 【0007】 This disclosure is made to solve such problems and aims to provide an occupant monitoring camera that can prevent stray light from reaching the lens regardless of the camera's field of view. [Means for solving the problem] 【0008】 To solve the above problems, the occupant monitoring camera according to this disclosure comprises a camera for imaging the occupants of a vehicle, a light source for illuminating the occupants, a light-shielding member provided around the lens of the camera for blocking light incident from the outside, and a cover provided between the camera and the occupants, wherein the shape of the surface of the light-shielding member facing the cover is saw-toothed. [Effects of the Invention] 【0009】 According to this disclosure, it is possible to prevent stray light from reaching the lens regardless of the camera's field of view. [Brief explanation of the drawing] 【0010】 [Figure 1] Figure 1 is a cross-sectional view showing an example of the configuration of an occupant monitoring camera according to an embodiment. [Figure 2] Figure 2 is a diagram illustrating the shape of the light-shielding member according to the embodiment. [Figure 3]Figure 3 is a diagram illustrating the reflection of light in a light-shielding member according to an embodiment. [Figure 4] Figure 4 is a diagram illustrating the reflection of light in a light-shielding member according to an embodiment. [Figure 5] Figure 5 is a diagram illustrating the reflection of light in a light-shielding member according to an embodiment. [Figure 6] Figure 6 is a cross-sectional view showing another example of a light-shielding member according to the embodiment. [Figure 7] Figure 7 is a cross-sectional view showing an example of another configuration of the occupant monitoring camera according to the embodiment. [Modes for carrying out the invention] 【0011】 <Embodiment> <Structure> Figure 1 is a cross-sectional view showing an example of the configuration of an occupant monitoring camera according to an embodiment. The occupant monitoring camera is installed inside the vehicle. The occupant monitoring camera monitors, for example, whether the occupant is distracted, drowsy, or incapacitated. 【0012】 As shown in Figure 1, the occupant monitoring camera comprises a lens 2, a lens holder 3, an image sensor substrate 4, a light-shielding member 5, a light source 7, a light source substrate 8, and a control board 10, all of which are housed inside the housing 1. In addition, openings are provided in the housing 1 in the direction of the camera's shooting direction and the illumination direction of the light source 7, and a cover 11 is provided to close these openings. 【0013】 An image sensor (not shown) is provided on the image sensor substrate 4, and a lens 2 is provided on the image sensor. The lens holder 3 holds the lens 2. The lens 2, the lens holder 3, and the image sensor substrate 4 constitute a camera for imaging a vehicle occupant. When the camera captures an image of the occupant, the occupant is present within the viewing angle 6 of the camera. In the example of FIG. 1, three lenses 2 are shown, but the number of lenses 2 is not limited to this. The lens 2 may be a wide-angle lens. A wide-angle lens refers to a lens with a wide viewing angle that can project a wide range (for example, a lens with a viewing angle of 100 degrees or more). 【0014】 A light source 7 for irradiating light to the occupant is provided on the light source substrate 8. The light source 7 emits light having, for example, an infrared wavelength. When the camera captures an image of the occupant, the occupant is present within the illumination range 9 of the light source 7. 【0015】 The control board 10 controls each component of the occupant monitoring camera, such as the image sensor substrate 4 and the light source substrate 8. Note that the control board 10 may be disposed outside the housing 1. 【0016】 The light shielding member 5 is provided around the lens 2 and shields the light incident from the outside. 【0017】 The cover 11 is provided between the camera and the occupant. The cover 11 is formed of a material with a low visible light transmittance and visually shields the camera from being seen by the occupant. Thereby, it is possible to prevent the occupant from feeling that they are being seen by the camera. 【0018】 <Shape of the light shielding member 5> Generally, the light shielding member is provided around the lens so as not to limit the viewing angle of the camera, and a gap is formed between the light shielding member and the cover. Among the light incident from the outside passing through this gap, the light that is reflected by the inside of the housing, the light shielding member, and the cover and reaches the occupant increases the visibility of the occupant (makes it easier for the occupant to visually recognize the camera), and the light that reaches the lens becomes stray light. 【0019】 On the other hand, in the passenger monitoring camera according to Embodiment 1, the shape of the surface of the light shielding member 5 facing the cover 11 is a sawtooth shape (see FIG. 2). In FIG. 2, an enlarged view of the light shielding member 5 on the right side of FIG. 1 is shown, but the shape of the light shielding member 5 on the left side of FIG. 1 is also the same (sawtooth shape). 【0020】 As shown in FIG. 2, the apex portions of the sawtooth shape of the light shielding member 5 are positioned along the envelope surface of the viewing angle 6 (the outermost surface of the viewing angle 6). The inclined surfaces constituting the sawtooth shape are positioned such that the facing inclined surfaces form an acute angle. 【0021】 FIGS. 3 to 5 show how the light incident on the light shielding member 5 from the outside is reflected by the light shielding member 5. The arrows in each figure indicate the traveling direction of the light. As shown in FIGS. 3 to 5, the light incident on the light shielding member 5 from the outside is reflected by the sawtooth shape of the light shielding member 5 and is emitted in a direction different from the direction of the passenger and the direction of the lens 2. 【0022】 By making the shape of the surface of the light shielding member 5 facing the cover 11 a sawtooth shape, it is possible to prevent the incident light from the outside from reaching the lens 2, so that it is possible to prevent the generation of stray light that reaches the lens 2 without performing the dimpling process disclosed in Patent Document 1. Therefore, it is possible to prevent the generation of stray light that reaches the lens 2 regardless of the viewing angle of the camera. 【0023】 In addition, by adjusting the angle and depth of the sawtooth shape, the generation of stray light can be reduced, so that the overall shape of the light shielding member 5 can be made substantially flat. Therefore, the thickness of the light shielding member 5 in the optical axis direction of the camera can be made sufficiently smaller than the height of the lens 2 (the total height of the three lenses 2 in the example of FIG. 1). 【0024】 Note that the sawtooth shape of the light shielding member 5 is not limited to the shape shown in FIGS. 1 and 2, and may be, for example, the shape shown in FIG. 6. In the sawtooth shape shown in FIG. 6, the innermost apex (the apex closest to the lens 2) is positioned so as not to touch the envelope surface of the viewing angle 6. 【0025】 <Arrangement of light source substrate 8 and control substrate 10> When a camera using a wide-angle lens is installed, the housing size relative to the plane normal to the camera's optical axis increases, regardless of whether or not a light-shielding member is present. On the other hand, in this embodiment, the overall shape of the light-shielding member 5 can be made almost planar, making it possible to place the light source substrate 8 in the space between the light-shielding member 5 and the image sensor substrate 4 (the space in the direction of the camera's optical axis). Furthermore, as shown in Figure 7, the control substrate 10 can be placed in the space between the light-shielding member 5 and the image sensor substrate 4. This configuration contributes to making the occupant monitoring camera thinner and smaller. 【0026】 In Figure 7, not only the control board 10 but also the light source board 8 is placed on the light-shielding member 5. This configuration allows the light source board 8 and the control board 10 to be prepared separately as modules before being incorporated into the housing 1, increasing the flexibility of how they can be incorporated into the housing 1 and making it easier to manufacture the occupant monitoring camera. 【0027】 In Figure 7, by forming the light-shielding member 5 and the housing 1 with a conductive material, the light source substrate 8 and the control substrate 10 can be covered with a conductive material, thus easily achieving electromagnetic compatibility. In particular, by forming the light-shielding member 5 with a metallic material, it can be used as a heat dissipation member to dissipate the heat generated by the light source substrate 8 and the control substrate 10. 【0028】 In the example shown in Figure 7, two light sources 7 are displayed, but the number of light sources 7 is not limited to this. If lens 2 is a wide-angle lens, the field of view 6 becomes larger, so there may be two or more light sources 7 to adequately illuminate the entire field of view 6. 【0029】 It should be noted that the embodiments may be modified or omitted as appropriate within the scope of this disclosure. 【0030】 <Note> The various aspects of this disclosure are summarized below as an appendix. 【0031】 (Note 1) A camera that images the occupants of the vehicle, A light source that illuminates the crew member, A light-shielding member is provided around the lens of the aforementioned camera to block light incident from the outside, A cover is provided between the camera and the occupant, Equipped with, The shape of the surface of the light-shielding member facing the cover is saw-toothed, in this occupant monitoring camera. 【0032】 (Note 2) The aforementioned lens is a wide-angle lens, as described in Appendix 1 of the crew monitoring camera. 【0033】 (Note 3) An occupant monitoring camera as described in Appendix 1 or 2, for monitoring the occupant's distraction, drowsiness, or inability to drive. [Explanation of symbols] 【0034】 1 Housing, 2 Lens, 3 Lens holder, 4 Image sensor substrate, 5 Light-shielding material, 6 Field of view, 7 Light source, 8 Light source substrate, 9 Illumination range, 10 Control board, 11 Cover.

Claims

[Claim 1] A camera that images the occupants of the vehicle, A light source that illuminates the crew member, A light-shielding member is provided around the lens of the aforementioned camera to block light incident from the outside, A cover is provided between the camera and the occupant, Equipped with, The shape of the surface of the light-shielding member facing the cover is saw-toothed, in this occupant monitoring camera. [Claim 2] The occupant monitoring camera according to claim 1, wherein the lens is a wide-angle lens. [Claim 3] The occupant monitoring camera according to claim 1 or 2, for monitoring the occupant's distracted driving, drowsiness, or inability to drive.

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