Blind Spot Support Device

Abstract

When other light-shielding members are present near the member to which the blind spot assist device is attached, the reduction in visibility of the scene in the blind spot area caused by those light-shielding members is suppressed. [Solution] The blind spot assist device 1 includes a transmissive reflective surface 2a that reflects a portion of the ambient light L1, including light from the blind spot region, and transmits the other portion of the ambient light, and a reflective surface 3a that reflects the light reflected by the transmissive reflective surface 2a back towards the transmissive reflective surface. The blind spot assist device 1 includes a light-shielding member 4 that is positioned on the opposite side of the reflective surface 3a, with the transmissive reflective surface 2a in between, and has a plurality of first light-shielding portions 41 and a second light-shielding portion 42. A portion of the plurality of first light-shielding portions 41 is positioned so as to overlap with the incident side edge E30 of the reflective surface 3a or its image when viewed from an arbitrarily determined reference viewpoint position P1. The second light-shielding portion 42 is positioned so as to hide a light-shielding region BC1 of the second member that is positioned adjacent to the first member when viewed from a second viewpoint position P2, which is a predetermined distance from the reference viewpoint position P1.

Description

Technical Field

[0001] The present disclosure relates to a blind spot assisting device that is attached to a member that creates a blind spot area and allows the viewer to visually recognize the scene in the blind spot area.

Background Art

[0002] Conventionally, examples of this type of blind spot assisting device include those described in Patent Document 1. The blind spot assisting device described in Patent Document 1 includes a semi-transmissive mirror and a reflective mirror arranged opposite each other, and a light shielding member composed of a plurality of louvers attached to an emission surface located on the side opposite to the reflective mirror among the semi-transmissive mirrors. This blind spot assisting device transmits part of the light from the blind spot area through the semi-transmissive mirror, reflects and guides the other part of the light through the semi-transmissive mirror and the reflective mirror, and emits the light over the entire emission surface of the semi-transmissive mirror, allowing the viewer to visually recognize the scene in the blind spot area.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the blind spot assisting device described in Patent Document 1, the light hitting the end of the reflective mirror on the semi-transmissive mirror side is guided, but part of the plurality of louvers is arranged at a position overlapping the image of the light when viewed from the eye point so that the light does not reach the eye point of the viewer. As a result, in this blind spot assisting device, the image of the end of the reflective mirror is blocked by the plurality of louvers, improving the visibility of the scene in the blind spot area. Hereinafter, for convenience of explanation, the position of the eye point that serves as a reference when arranging the plurality of louvers is referred to as the "reference viewing point position".

[0005] Here, for example, if the viewer's right eye is at the reference viewpoint position, the viewer's left eye will be at a second viewpoint position different from the reference viewpoint position. In this case, if there is another light-blocking area (for example, the black ceramic part of the windshield) near the component to which the blind spot assist device is attached (for example, the front pillar), that other light-blocking area may not be hidden by the multiple louvers. In this case, the part of the scene viewed by the viewer through the blind spot assist device that is the other light-blocking area may appear as a black gap, potentially reducing visibility.

[0006] In view of the above, this disclosure aims to provide a blind spot assist device that can suppress the reduction in visibility of the scene in a blind spot area caused by other light-shielding members when other light-shielding members are present in the vicinity of a member that creates a blind spot area. [Means for solving the problem]

[0007] According to one aspect of this disclosure, the blind spot assist device is attached to a first member (P) that creates a blind spot region and is a blind spot assist device that makes the image of the blind spot region visible, External light (L1), including light from a blind spot, is incident on a transmissive reflective surface (2a, 5b) that reflects a portion of the external light and transmits the other portion. Reflective surfaces (3a, 5c) are positioned opposite the transmissive reflective surface and reflect the light reflected by the transmissive reflective surface back towards the transmissive reflective surface, The device comprises a light-shielding member (4) having a plurality of first light-shielding portions (41) and second light-shielding portions (42) that are positioned on the opposite side of the reflective surface from the transmissive reflective surface and block external light incident on the transmissive reflective surface at a predetermined angle, A portion of the multiple first light-shielding sections is positioned so as to overlap with the incident-side end of the reflective surface (E30, E5c0) or the image of the incident-side end reflected on the reflective surface, when viewed from an arbitrarily determined reference viewpoint position (P1). At least one of the multiple first light-shielding portions is positioned so as to overlap with the incident-side edge (E20, E5b) of the transmitted reflective surface when viewed from the reference viewpoint position. The second light-shielding section is positioned to conceal the light-shielding portion (BC1) of the second member, which is adjacent to the first member, when viewed from a second viewpoint position (P2) located at a predetermined distance from the reference viewpoint position.

[0008] This blind spot assist device comprises a transmissive reflective surface that transmits / reflects ambient light, including light from the blind spot region; a reflective surface positioned opposite the transmissive reflective surface and reflecting light toward the transmissive reflective surface; and a light-shielding member positioned on the opposite side of the reflective surface, with the transmissive reflective surface in between. The light-shielding member has a plurality of first light-shielding sections and a second light-shielding section. Some of the plurality of first light-shielding sections are positioned so as to overlap with the incident-side end of the reflective surface or the image of the incident-side end reflected on the reflective surface when viewed from a reference viewpoint position, thereby improving the visibility of the blind spot region by preventing the viewer from seeing the incident-side end and its image. The second light-shielding section is positioned so as to hide the light-shielding portion of the second member adjacent to the first member that creates the blind spot region when viewed from a second viewpoint position at a predetermined distance from the reference viewpoint position, thereby improving the visibility of the blind spot region by preventing the viewer from seeing the light-shielding portion. Therefore, this blind spot assist device can suppress the reduction in visibility caused by the second member located near the first member.

[0009] The reference numerals in parentheses attached to each component indicate an example of the correspondence between that component and the specific components described in the embodiments described later. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view showing the mounting state of the blind spot assist device according to the first embodiment. [Figure 2] This is a perspective view of the blind spot assist device as seen from direction II in Figure 1. [Figure 3] Figure 1 is an explanatory diagram of the light guide in the blind spot assist device. [Figure 4] This is an explanatory diagram illustrating the prevention of display omissions using a blind spot assist device having a second light-shielding section. [Figure 5] This is an explanatory diagram illustrating the display gap in a comparative example blind spot assist device that does not have a second light-shielding section. [Figure 6] It is a cross-sectional view showing the blind spot assisting device of the second embodiment. [Figure 7] It is an explanatory diagram of light guiding in the blind spot assisting device of FIG. 6. [Figure 8] It is an explanatory diagram of the arrangement of the second light shielding part in the blind spot assisting device of the second embodiment. [Figure 9] It is a cross-sectional view showing the attachment state of the blind spot assisting device of the third embodiment. [Figure 10] It is an explanatory diagram of light guiding in the light guide body of the blind spot assisting device of FIG. 9. [Figure 11] It is an explanatory diagram of the arrangement of the first light shielding part in the blind spot assisting device of FIG. 9. [Figure 12] It is a cross-sectional view showing a modified example of the blind spot assisting device of the third embodiment. [Figure 13] It is an explanatory diagram of the arrangement of the second light shielding part in the blind spot assisting device of FIG. 12. [Figure 14] It is a diagram showing another shape example of the light shielding part in the blind spot assisting device.

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present disclosure will be described based on the drawings. In the following embodiments, parts that are the same or equivalent to each other are denoted by the same reference numerals for description.

[0012] (First Embodiment) The blind spot assisting device 1 of the first embodiment will be described. The blind spot assisting device 1 of this embodiment is attached to a member or an obstacle that blocks the user's field of vision and creates a blind spot area, and guides external scene light including light from the blind spot area to the user's side to make the blind spot area visible. The blind spot assisting device 1 is attached to, for example, the front pillar P of a vehicle as shown in FIG. 1, and allows the user to visually recognize the scene in the blind spot area caused by the pillar. In this specification, the case where the blind spot assisting device 1 is attached to the front pillar P is described as a representative example, but it is not limited to such in-vehicle applications.

[0013] 〔Basic Configuration〕 The blind spot assisting device 1 of this embodiment includes, for example, as shown in FIG. 1, a transmissive and reflective member 2 having a transmissive and reflective surface 2a that transmits a part of light and reflects another part of light, and a reflective member 3 that is disposed opposite to the transmissive and reflective member 2 in parallel and has a reflective surface 3a that reflects light. The blind spot assisting device 1 further includes a light shielding member 4 disposed on the opposite side of the reflective member 3 with the transmissive and reflective member 2 interposed therebetween. As shown in FIG. 2 for example, in the blind spot assisting device 1, the light shielding member 4 is attached to the transmissive and reflective member 2, and the transmissive and reflective member 2 and the reflective member 3 that constitute a pair of mirrors are attached to a housing or a holding member not shown in the figure, and these two members are held in a substantially parallel state. Substantially parallel includes a state that is not a completely parallel state due to errors in attachment to a holding member or the like not shown in the figure, but can be regarded as being substantially parallel in addition to a completely parallel state.

[0014] As shown in FIG. 3 for example, when outside scene light L1 enters the side of the transmissive and reflective member 2 from behind the reflective member 3 in the blind spot assisting device 1, a part of the outside scene light L1 is repeatedly reflected by the transmissive and reflective member 2 and the reflective member 3, and another part of the light is emitted from the transmissive and reflective member 2. The outside scene light L1 is light that enters the transmissive and reflective member 2 from the side of the reflective member 3, and includes light from a blind spot area generated by a member such as a front pillar P. Thereby, the blind spot assisting device 1 guides the outside scene light L1 incident from the blind spot area between the transmissive and reflective member 2 and the reflective member 3, and emits the outside scene light L1 to the outside over a wide range of the transmissive and reflective member 2, so that the user can visually recognize the scene of the blind spot area.

[0015] For the sake of explanation, as shown by the arrows in Figure 1, for example, the direction normal to the transmissive reflective surface 2a of the transmissive reflective member 2 and the reflective surface 3a of the reflective member 3, which face each other, i.e., the direction corresponding to the thickness direction of the blind spot assist device 1, will be referred to as the "thickness direction D1". The state in which the blind spot assist device 1 or its components are viewed from a direction along the thickness direction D1 will be referred to as the "top view". Furthermore, the direction along the plane formed by the transmissive reflective surface 2a of the transmissive reflective member 2, and the direction from the incident end 2A, which is the end of the portion of the transmissive reflective member 2 that extends beyond the reflective member 3 in the top view, toward the opposite end 2B, will be referred to as the "light guiding direction D2". The light guiding direction D2 can be said to be the direction along which light is guided by the transmissive reflective member 2 and the reflective member 3. The thickness direction D1 and light guiding direction D2 shown by the arrows in Figure 2 and subsequent figures correspond to the directions shown by the arrows in Figure 1. Furthermore, in the light guide direction D2, the end of the reflective member 3 on the incident end 2A side is referred to as the "incident end 31".

[0016] The light-transmitting reflective member 2 is a member that emits a portion of the ambient light L1 toward the user and reflects the other portion toward the light-reflecting member 3, and in this embodiment it is a half-mirror. The light-transmitting reflective member 2 has, for example, a substrate made of any translucent material such as glass or a resin such as polyethylene terephthalate, and a light-transmitting reflective layer made of a known light-transmitting reflective film such as a metal vapor-deposited film made of a metal material such as aluminum or a dielectric multilayer film. The light-transmitting reflective member 2 is, for example, in the shape of a rectangular plate as shown in Figure 2, and the end of the region that extends beyond the light-reflecting member 3 when viewed from the light-reflecting member 3 side is the incident end 2A.

[0017] As shown in Figure 3, for example, the light-transmitting reflective member 2 specularly reflects a portion of the ambient light L1 toward the reflecting member 3 toward the incident end 2A, and transmits the other portion of the ambient light L1, which is then emitted toward the opposite side from the reflecting member 3. For example, one side of the light-transmitting reflective member 2 facing the reflecting member 3 is the light-transmitting reflective surface 2a, and the other side opposite the light-transmitting reflective surface 2a is the light-emitting surface 2b. In other words, the ambient light L1 is repeatedly reflected by the light-transmitting reflective member 2 and the reflecting member 3, and is emitted from a wide area of ​​the light-emitting surface 2b of the light-transmitting reflective member 2. A light-shielding member 4 is attached to the light-shielding surface 2b side of the light-transmitting reflective member 2.

[0018] The reflective member 3 is a reflective member that reflects visible light to the transmitting reflective member 2 side with a reflectivity of a predetermined value or higher (for example, 80% or more, though not limited to this), and in this embodiment, it is a mirror. The reflective member 3 is composed of, for example, a substrate made of any material and a reflective layer made of a known reflective material such as a metallic material formed on the substrate. As shown in Figure 2, for example, the reflective member 3 is shaped like a rectangular plate when viewed from above, and is arranged substantially parallel to the transmitting reflective member 2 with a position offset in the light guide direction D2. As shown in Figure 3, for example, the reflective member 3 specularly reflects the reflected light from the ambient light L1 that has been reflected by the transmitting reflective member 2 towards the transmitting reflective member 2 side.

[0019] The light-shielding member 4, as shown in Figure 2 for example, has a plurality of first light-shielding portions 41, a second light-shielding portion 42, and a frame portion 43 that holds the light-shielding portions 41 and 42. The light-shielding member 4 is made of a light-shielding material, in part or in whole, and is a member that does not transmit light.

[0020] The multiple first light-shielding sections 41 and second light-shielding sections 42 are louvers and are arranged apart from each other in the light-guiding direction D2. Each of the multiple first light-shielding sections 41 and second light-shielding sections 42 is inclined at a predetermined angle with respect to the ejection surface 2b such that its tip faces the user's viewpoint position P1 or P2, which will be described later. The multiple first light-shielding sections 41 and second light-shielding sections 42 prevent external light L2 directed from the outside toward the ejection surface 2b from reaching the ejection surface 2b and undergoing surface reflection, as shown in Figure 3, for example, and prevent external light L2 from superimposing on the ambient light L1 that passes through the transmission-reflecting member 2.

[0021] Multiple first light-shielding portions 41 are arranged so that the edge E30 of the incident end 3A of the reflective member 3 and its image do not enter the user's field of view, thereby improving visibility in the blind spot area. Second light-shielding portions 42 are arranged so that the light-shielding portion of the second member adjacent to the first member that creates the blind spot area does not enter the user's field of view, thereby improving visibility in the blind spot area. Details of the arrangement of the first light-shielding portions 41 and the second light-shielding portions 42 will be described later. The frame portion 43 is, for example, shaped like a frame that follows the outer shape of the transmitted reflective member 2 when viewed from above, and is used to hold the light-shielding portions 41 and 42, as well as to attach the light-shielding member 4 to the ejection surface 2b.

[0022] The above describes the basic configuration of the blind spot assist device 1 of this embodiment. The blind spot assist device 1 only needs to include a light-shielding member 4 having light-shielding portions 41 and 42 arranged in a predetermined configuration, with the light-transmitting reflective member 2 and the reflective member 3 arranged substantially parallel to each other, and the shape and other aspects may be changed as appropriate within the limits of what is possible. For example, the light-transmitting reflective member 2 and the reflective member 3 may be not only rectangular plates, but also other shapes such as a wedge shape that becomes narrower toward the end of the light-guiding direction D2.

[0023] [Arrangement of light-shielding components] Next, the arrangement of the multiple first light-shielding sections 41 and the second light-shielding sections 42 and their effects will be explained with reference to Figures 4 and 5. In Figures 4 and 5, although they are not components of the blind spot assist devices 1 and 100, hatching is applied to the area connecting a part of the black ceramic section BC and the second viewpoint position P2, which will be described later, i.e., the area that can be seen from the second viewpoint position P2. Also, in Figures 4 and 5, the front pillar P to which the blind spot assist devices 1 and 100 are attached is omitted for clarity.

[0024] The blind spot assist device 1 is, for example, mounted on the front pillar P and guides light from the blind spot area created by the front pillar P. As shown in Figure 4, the light emitted from the emission surface 2b reaches the reference viewpoint position P1, allowing the user to see the scene in the blind spot area. At this time, the reference viewpoint position P1 is, for example, the center of the driver's eye lip EP of the vehicle to which the blind spot assist device 1 is mounted.

[0025] The eye lip EP is an elliptical eye range that statistically represents the distribution of the driver's eye positions in a vehicle equipped with a blind spot assist device 1, and is defined, for example, in the Japanese Industrial Standard JIS D0021:1998. The eye lip EP is, for example, the 95th percentile eye lip, but is not limited to this, and the 90th percentile eye lip or the 99th percentile eye lip may also be used. In the two ellipses of the eye lip EP shown in Figures 4 and 5, for example, the upper ellipse corresponds to the right eye and the lower ellipse corresponds to the left eye.

[0026] Here, assuming that there are no multiple first light-shielding sections 41 when the user views the transmissive reflective member 2 from a reference viewpoint position P1, the user will be able to see not only the scene in the blind spot region, but also the edge E30 on the reflective surface 3a side of the incident end 31 of the reflective member 3 and its image. The multiple first light-shielding sections 41 are arranged so as to overlap with the edge E30 or its image when viewed from the reference viewpoint position P1, so that the edge E30 and its image do not overlap with the scene in the blind spot region that the user is intended to see.

[0027] Specifically, as shown in Figure 4, one first light-shielding section 41 is positioned and angled along a virtual straight line VL1 connecting the reference viewpoint position P1 and the edge E30. As a result, when viewed from the reference viewpoint position P1, the edge E30 is superimposed on the aforementioned first light-shielding section 41 and becomes invisible to the user, improving visibility in the blind spot area. The virtual straight line VL1 is the boundary between the area where the outside scenery is visible due to light transmitted through the transmission-reflective member 2 without any reflection of the outside scenery light L1, and the area where the outside scenery is visible due to light that has been reflected once by the transmission-reflective member 2 and the reflective member 3, respectively, and then transmitted through the transmission-reflective member 2.

[0028] For the sake of simplicity, the following will refer to the light emitted from the emission surface 2b of the transmission-reflecting member 2, where the number of round trips between the transmission-reflecting member 2 and the reflecting member 3 is n (n: a positive integer including 0), as "n-times reflected light." Furthermore, the region of the emission surface 2b that allows the outside scenery to be seen due to the n-times reflected light will be referred to as the "(n+1)th region." In other words, the emission surface 2b is divided into the 1st region, the 2nd region, ..., the (n+1th)th region, starting from the incident end 2A and moving towards the terminal end 2B.

[0029] Here, let T be the distance in the thickness direction D1 between the transmissive reflective member 2 and the reflective member 3. Points E31 and E32 are obtained by moving the edge E30 2T and 4T along the thickness direction D1 to the opposite side of the transmissive reflective member 2, respectively. At this time, when viewed from the reference viewpoint position P1, the image of edge E30 is visible on the virtual line VL2 connecting the reference viewpoint position P1 and point E31, and on the virtual line VL3 connecting the reference viewpoint position P1 and point E32. The virtual line VL2 is the boundary between the second and third regions of the injection surface 2b. The virtual line VL3 is the boundary between the third and fourth regions of the injection surface 2b.

[0030] One first light-shielding section 41 is positioned and angled along a virtual straight line VL2. Another first light-shielding section 41 is positioned and angled along a virtual straight line VL3. In this way, the multiple first light-shielding sections 41 are positioned at the boundary between adjacent nth region and (n+1)th region, and at an angle along a virtual straight line connecting the boundary and the reference viewpoint position P1. As a result, when viewed from the reference viewpoint position P1, the image of edge E30 is not superimposed on the multiple first light-shielding sections 41 and is not visible to the user, improving visibility in the blind spot area.

[0031] Furthermore, the other first light-shielding portion 41 is positioned and angled along a virtual straight line connecting the edge E20 of the ejection surface 2b and the reference viewpoint position P1 at the incident end 2A of the transmission-reflecting member 2. In other words, the multiple first light-shielding portions 41 are positioned apart at the boundary between two adjacent regions of the edge E20 and the ejection surface 2b, and the angle they make with the ejection surface 2b increases as they approach the reference viewpoint position P1. Also, the multiple first light-shielding portions 41 only need to be long enough to block ambient light L2, with the length measured from the base to the tip on the ejection surface 2b side, and they may all be the same length, or some or all of them may be of different lengths.

[0032] Here, the windshield WS adjacent to the front pillar P has a black ceramic section BC near its outer edge that provides light shielding. The black ceramic section BC protects the adhesive used to attach the windshield WS to the vehicle body from external light. The front pillar P to which the blind spot assist device 1 is attached corresponds to the first component, and the black ceramic section BC adjacent to the front pillar P corresponds to the second component.

[0033] When viewed from another viewpoint located at the eye lip EP, if part or all of the black ceramic part BC is in the field of view, the user may perceive the black ceramic part BC as a display gap, reducing visibility in the blind spot area. The second light-shielding part 42 is provided to prevent this display gap caused by the second member. As shown in Figures 4 and 5 below, the "second viewpoint position P2" is defined as a position in the left eye's eye lip that is a predetermined distance X (mm) away from the reference viewpoint position P1. The distance X is, for example, 65 mm, which is the 50th percentile value for interpupillary width in elderly men in "Kawachi, Makiko & Mochimaru, Masaaki, 2008: Japanese Head Dimensions Database 2001, National Institute of Advanced Industrial Science and Technology H16PRO-212," but is not limited to this. In other words, the second viewpoint position P2 is, for example, a position that is up to the interpupillary width of a person away from the reference viewpoint position P1.

[0034] Here, as shown in Figure 5, we will examine the comparative example blind spot assist device 100.

[0035] The comparative example blind spot assist device 100 includes a light-shielding member 10 having a plurality of light-shielding parts 11 corresponding to the first light-shielding part 41 and a frame part (not shown), instead of the light-shielding member 4. The light-shielding member 10 does not have a part corresponding to the second light-shielding part 42. In this case, when the comparative example blind spot assist device 100 is viewed from the reference viewpoint position P1, the edge E30 of the reflective member 3 and its image overlap with the plurality of light-shielding parts 11, thus suppressing the reduction in visibility of the scene in the blind spot area caused by the reflective member 3.

[0036] However, in the comparative example blind spot assist device 100, as shown in Figure 5, the light-shielding member 10 is not positioned on the virtual straight line VL4 connecting the second viewpoint position P2 and the region BC1, which is part of the black ceramic section BC. As a result, at the second viewpoint position P2, a portion of the black ceramic section BC1 located at the end opposite to the front pillar P appears black, becoming a so-called black area, which the user perceives as a gap in the display in the blind spot area.

[0037] In contrast, the blind spot assist device 1, as shown in Figure 4 for example, has the second light-shielding portion 42 positioned and at an angle along a virtual straight line VL4 connecting the second viewpoint position P2 and the area BC1 of the black ceramic portion BC. As a result, the area BC1 of the black ceramic portion BC that may appear black and the second light-shielding portion 42 overlap, so that even when viewed from the second viewpoint position P2, the reduction in visibility of the blind spot area caused by area BC1 is suppressed. Note that the black ceramic portion BC is not visible to the user at the reference viewpoint position P1 because it is located on the reflective member 3 side of the virtual straight line VL1, and at the second viewpoint position, the areas other than area BC1 are not visible to the user because they are located on the reflective member 3 side of the virtual straight line VL4.

[0038] The second viewpoint position P2 is, for example, in the examples of Figures 4 and 5, a position in the left eye's eye lip, a predetermined distance X away from the reference viewpoint position P1. The second viewpoint position P2 is set, for example, at the position where the angle of the virtual straight line VL4 with respect to the ejection surface 2b is largest. In other words, when the reference viewpoint position P1 is fixed, the second viewpoint position P2 is the position in the right or left eye's eye lip where the light-shielding portion of the second member (region BC1 in Figures 4 and 5) is most clearly visible. The second light-shielding portion 42 is positioned to block the virtual straight line VL4 connecting the second viewpoint position P2 set as described above and the light-shielding portion of the second member, thereby suppressing display gaps caused by the light-shielding portion even when viewed from other viewpoints of the eye lip EP.

[0039] The blind spot assist device 1 of this embodiment comprises a transmission / reflection member 2 that transmits / reflects ambient light L1 including light from the blind spot region, a reflection member 3 positioned opposite to it and reflecting light toward the transmission / reflection surface 2a, and a light-shielding member 4 positioned on the opposite side of the reflection surface, with the transmission / reflection member 2 in between. The plurality of first light-shielding portions constituting the light-shielding member 4 are positioned so as to overlap with the edge E30 or image of the incident end 31 of the reflection member 3 when viewed from a reference viewpoint position P1, thereby improving the visibility of the blind spot region by preventing the incident end and its image from being seen by the viewer. Furthermore, the second light-shielding portion 42 of the light-shielding member 4 is positioned so as to hide the light-shielding portion of the second member adjacent to the first member that creates the blind spot region when viewed from a second viewpoint position P2, thereby improving the visibility of the blind spot region by preventing the viewer from seeing the light-shielding portion. Therefore, this blind spot assist device can suppress the reduction in visibility caused by the light-shielding portion of the second member adjacent to the first member that creates the blind spot area.

[0040] (Second Embodiment) The blind spot assist device 1 of the second embodiment will be described with reference to Figures 6 to 8. In Figure 7, among the multiple regions 21 to 23 that constitute the transmissive reflective member 2, the regions in the reflective state, which will be described later, are hatched, and the one region in the transparent state, which will be described later, is shown in white.

[0041] The blind spot assist device 1 of this embodiment differs from the first embodiment in that, as shown in Figure 6, for example, the transmissive reflective member 2 is divided into multiple regions and is a dimming member that can switch between a transparent state and a reflective state. This embodiment will mainly explain this difference.

[0042] In this embodiment, the light-transmitting and reflective member 2 is divided into a plurality of regions 21 to 23 along the light-guiding direction D2, and is a light-adjusting member that can switch between a transparent state that transmits visible light and a reflective state that reflects visible light for each region 21 to 23. The light-transmitting and reflective member 2 may also be called a "light-adjusting mirror". As the light-adjusting member, for example, electrochromic or gaschromic can be used. In the case of an electrochromic light-adjusting member, for example, a transparent electrode such as ITO is laminated on a transparent substrate such as glass in the following order: an electrochromic layer made of an alloy thin film material, an electrolyte layer, and a transparent counter electrode. The electrochromic layer may also be called a "light-adjusting mirror layer". The electrolyte layer may also be called an ion storage layer. In the light-adjusting member, for example, when a voltage is applied between the transparent electrode and the counter electrode, hydrogen ions move from the electrolyte layer to the electrochromic layer in a mirror state (reflective state), and the alloy thin film material changes to a non-metallic state, resulting in a transparent state. Thus, when using electrochromic components, the dimming element can be switched between a transparent state and a reflective state depending on whether or not voltage is applied.

[0043] Note that Figure 6 shows a representative example where the transmissive reflective member 2 is divided into three regions 21-23, but it is not limited to this, and the number of regions of the transmissive reflective member 2 can be changed as appropriate. Also, in Figure 6, for clarity, the boundaries of each of the regions 21-23 are shown with solid lines, but the boundaries between transparent regions are not visible to the user.

[0044] The transmissive-reflective member 2 has transparent electrodes (not shown) in each of the multiple regions 21 to 23 connected to wiring (not shown), such as an FPC, and is also connected via the wiring to a circuit board (not shown) for drive control. Thus, the transmissive-reflective member 2 can control the switching between transparent and reflective states in each of the multiple regions 21 to 23. The circuit board is an electronic unit consisting of a board with circuit wiring (not shown) on which a CPU, ROM, RAM, I / O (not shown) and other components are mounted. It is connected to an external power supply (not shown) and positioned at an arbitrary location invisible to the user.

[0045] The transmissive reflective member 2 has one of its multiple regions 21 to 23 that is made transparent by the application of current, while the remaining regions are made reflective. For example, as shown in Figure 7, when the second region 22 of the transmissive reflective member 2 is transparent, the first region 21 and the third region 23 are in a reflective state, and ambient light L1 is emitted only from the second region 22. The transmissive reflective member 2 is then controlled to dim the light so that the transparent region is sequentially switched and ambient light L1 is emitted from the entire emission surface 2b. As a result, the transmissive reflective member 2 reflects ambient light L1 with high reflectivity in the reflective region and emits ambient light L1 with high transmittance in the transparent region.

[0046] The transmissive reflective member 2, for example, has a reflectivity of 70% or more and a transmittance of approximately 0% in the reflective state when no voltage is applied, and a transmittance of 70% or more in the transparent state. The transmissive reflective member 2 preferably satisfies S < 1 / C, where C (unit: Hz) is the temporal resolution of human vision, and S is the time required for dimming control to make all areas 21-23 of the transmissive reflective member 2 transparent once each, with S being the overall switching time. As a result, the transmissive reflective member 2 does not allow the user to perceive the dimming control and does not cause any discomfort due to the dimming control.

[0047] In this embodiment, the second light-shielding section 42 is positioned to hide boundary B from the second viewpoint position P2, as shown in Figure 8, for example, with the boundary closest to the virtual straight line VL4 among the boundaries of adjacent regions 21 to 23 of the transmissive reflective member 2 being designated as boundary B. As a result, the second light-shielding section 42 can suppress the reduction in visibility of the scene in the blind spot region caused by boundary B, in addition to the reduction in region BC1. In this embodiment, the transmissive reflective member 2 may cause discomfort to the user due to the overlap of images in the blind spot region at the boundary of regions 21 to 23. Therefore, in this embodiment, the second light-shielding section 42 is positioned to hide boundary B from the second viewpoint position P2, thereby preventing the user from seeing the overlapping portion of the images in the blind spot region and suppressing the reduction in visibility caused by boundary B.

[0048] According to this embodiment, the blind spot assist device 1 is obtained that has the same effects as the first embodiment described above. Furthermore, in the blind spot assist device 1 of this embodiment, since the transmissive reflective member 2 is a dimming member that can switch between a transparent state and a reflective state, the loss due to light absorption in the transmissive reflective member 2 is reduced, and the effect of increasing the amount of light emitted from the emission surface 2b is also obtained.

[0049] (Third embodiment) The blind spot assist device 1 of the third embodiment will now be described.

[0050] The blind spot assist device 1 of this embodiment differs from the first embodiment in that, as shown in Figure 9, for example, it has a single light guide 5 made of a light-transmitting material instead of the transmission-reflecting member 2 and the reflective member 3. This embodiment will mainly explain this difference.

[0051] The light guide 5 is a member having an incident portion 5a, a reflective surface 5c adjacent to the incident portion 5a, and an ejection surface 5b facing the incident portion 5a and the reflective surface 5c, as shown in Figure 9, for example. The light guide 5 is a transparent member of a single component made of a light-transmitting material. As the light-transmitting material, for example, resin materials such as polyethylene terephthalate, polycarbonate, polyethylene, and acrylic, or inorganic materials such as glass can be used. The light guide 5 has a mirrorless structure without a mirror made of a reflective material different from the light-transmitting material, and is designed to guide light by totally reflecting the incident light from the incident portion 5a inside. As the light guide 5, for example, the one described in Japanese Patent Application Publication No. 2023-28532 can be used. As shown in Figure 10, for example, the light guide 5 has a structure in which a portion of the ambient light L1 that enters the interior from the incident section 5a is emitted from the emission prism section 52 (described later), while the remaining portion of the ambient light L1 is reflected by total internal reflection by the flat section 53 and the reflective surface 5c (described later) and guided to the interior.

[0052] In this embodiment, the thickness direction D1 is the direction along the normal direction to the flat portion 53 or the reflective surface 5c, and corresponds to the thickness direction of the light guide 5. In this embodiment, the light guide direction D2 is the direction along the plane formed by the flat portion 53 of the emission surface 5b, and is the direction from the end on the incident portion 5a side toward the opposite end.

[0053] The incident section 5a consists of, for example, a plurality of incident prism sections 51, each having a triangular prism-like projection, arranged repeatedly and continuously along the light guide direction D2 with their extension directions aligned. For example, one side of the outer surface of the plurality of incident prism sections 51, opposite to the reflective surface 5c, serves as the incident surface 51a that allows ambient light L1 to enter the interior. For example, the heights of the portions protruding from the reflective surface 5c of the plurality of incident prism sections 51 are made approximately the same, and the incident surfaces 51a of each are arranged to be approximately parallel. "Approximately the same" includes not only cases where they are completely identical, but also cases where they are not completely identical due to unavoidable errors such as manufacturing errors, but are nearly identical. For the plurality of incident prism sections 51, the side of the outer surface facing the reflective surface 5c serves as the adjacent surface 21b. The inclination angle of the adjacent surface 21b is set to a predetermined value so as not to obstruct the incidence of ambient light L1 onto the incident surface 51a of the other adjacent incident prism section 51.

[0054] For the sake of explanation, in the following, of the ambient light L1 from the incident section 5a and the reflective surface 5c, the light that enters the interior from the incident section 5a will be referred to as "incident light," and the light that is emitted to the outside from the emission prism section 52, which will be described later, will be referred to as "emission light."

[0055] The light guide 5 is configured such that, for example, the inclination of the incident side surface connecting the incident section 5a and the emission surface 5b is greater than or equal to the incident angle φ, where φ is the incident angle of the incident light onto the flat section 53. This is to prevent the incident light from being emitted to the outside from the incident side surface. The incident angle φ of the incident light is the angle between the direction normal to the plane formed by the flat section 53 or the reflective surface 5c (hereinafter simply referred to as the "normal direction") and the direction of propagation of the incident light. The light guide 5 enables light guidance in a mirrorless structure by satisfying the total internal reflection condition in equation (1) below, assuming the refractive index of the constituent material is n and the external medium is air (refractive index = 1).

[0056] sinφ≧1 / n···(1) The ejection surface 5b has, for example, a plurality of ejection prism sections 52 which are triangular prism-shaped protrusions, and a plurality of flat sections 53 adjacent to them which are planes substantially parallel to the reflective surface 5c. The ejection surface 5b is the surface to which the incident light from the incident section 5a first reaches, and the ejection prism sections 52 and the flat sections 53 are arranged alternately and repeatedly along the light guide direction D2. For example, the ejection prism sections 52 and the flat sections 53 are arranged at equal intervals on the ejection surface 5b. The plurality of ejection prism sections 52 have ejection sections 52a which are flat surfaces that eject the incident light to the outside, and for example, they are arranged in parallel with their extending directions aligned. For example, the ejection sections 52a are parallel to the incident surface 51a. The plurality of flat sections 53 are, for example, flat surfaces located on the same plane, and are the first reflective surfaces that reflect the incident light toward the reflective surface 5c by total internal reflection. In other words, the ejection surface 5b corresponds to the transmitted reflective surface in this embodiment. The light guide 5 has a light-shielding member 4 attached to the emission surface 5b side.

[0057] The reflective surface 5c is a second reflective surface that reflects the light reflected by the flat section 53 towards the emission surface 5b by total internal reflection, i.e., it is a reflective surface that is paired with the emission surface 5b. The reflective surface 5c is the back surface when the emission surface 5b, which faces the user, is considered the front surface. The reflective surface 5c is positioned, for example, to face the first member to which the blind spot assist device 1 is attached, separated by a predetermined gap. The reflective surface 5c is, for example, approximately parallel to the flat section 53, and when light that has been totally reflected by the flat section 53 is incident at an incident angle φ, it is totally reflected towards the emission surface 5b by satisfying equation (1). In other words, the light guide 5 allows the user to see the scene in the blind spot area by having a portion of the incident light from the incident section 5a repeatedly reflected by the flat section 53 and the reflective surface 5c, while another portion of the incident light is emitted from the emission sections 52a of the multiple emission prism sections 52.

[0058] Furthermore, the end surface of the light guide 5 that connects the emission surface 5b and the reflective surface 5c may form a single plane together with the emission part 52a of the emission prism part 52, or it may have a different surface shape, or any shape may be used. In addition, the two surfaces of the light guide 5 located at both ends in the extension direction of the incident prism part 51 are non-optical surfaces that are not used for guiding incident light inside the light guide 5, i.e., for reflection, and their shape and other characteristics are arbitrary.

[0059] In this embodiment, as shown in Figure 11, for example, the light-shielding member 4 is positioned and angled such that, when viewed from the reference viewpoint position P1, one of the multiple first light-shielding portions 41 is aligned with a virtual straight line VL5 connecting the end portion E5b of the ejection surface 5b on the incident portion 5a side and the reference viewpoint position P1. The end portion E5b is, for example, the tip of the ejection prism portion 52 located at the end of the ejection surface 5b closest to the incident portion 5a. Assuming that the light-shielding member 4 is absent, when viewed from the reference viewpoint position P1, the edge E5c0 of the reflective surface 5c located at the boundary with the incident portion 5a corresponds to edge E30, and edge E5c0 and its image may enter the user's field of view.

[0060] Therefore, in this embodiment, one of the first light-shielding portions 41 is positioned and angled along a virtual straight line VL6 connecting the edge E5c0 and the reference viewpoint position P1. Here, let T be the distance in the thickness direction D1 between the flat portion 53 and the reflective surface 5c, and let points E5c1 and E5c2 be obtained by moving the edge E5c0 2T and 4T along the thickness direction D1 to the opposite side from the injection surface 5b, respectively. At this time, one of the first light-shielding portions 41 is positioned and angled along a virtual straight line VL7 connecting point E5c1 and the reference viewpoint position P1. Another one of the first light-shielding portions 41 is positioned and angled along a virtual straight line VL8 connecting point E5c2 and the reference viewpoint position P1. As a result, at the reference viewpoint position P1, the edge E5c0 of the light guide 5 and its image, as well as the end E5b of the emission surface 5b, overlap with the multiple first light-shielding parts 41, improving the visibility of the scene in the blind spot area.

[0061] Furthermore, the second light-shielding portion 42 is positioned to block a virtual straight line VL4 connecting a part of the black ceramic portion BC of the second member, the windshield WS, and the second viewpoint position P2, thereby concealing the area BC1 that appears black.

[0062] According to this embodiment, in addition to the effects of the first embodiment described above, by having a light guide 5 made of a single translucent material instead of the transmission-reflecting member 2 and the reflecting member 3, the blind spot assisting device 1 also has the effect of suppressing positional misalignment between the transmission-reflecting surface and the reflecting surface. Furthermore, since the light guide 5 is configured to guide the ambient light L1 inward by total internal reflection, the loss due to light absorption is reduced, and the effect of increasing the amount of emitted light is also obtained.

[0063] (Modified version of the third embodiment) The blind spot assist device 1 of the third embodiment described above may have a configuration in which the ejection surface 5b has multiple regions 5ba to 5bc with different ratios of the width of the flat portion 53 to the width of the ejection prism portion 52 (hereinafter referred to as "width ratio"), as shown in Figure 12, for example. Here, the width of the ejection prism portion 52 and the width of the flat portion 53 refer to the width in the light guide direction D2.

[0064] The ejection surface 5b is configured to have, for example, a first region 5ba, a second region 5bb, and a third region 5bc, each with a different width ratio, starting from the incident portion 5a side in the light guide direction D2. The width ratios of regions 5ba to 5bc are constant, and the width ratio decreases as the region moves further away from the incident portion 5a. Specifically, for example, the first region 5ba has the largest width ratio, followed by the second region 5bb, while the third region 5bc is composed only of multiple ejection prism portions 52. In other words, in regions 5ba to 5bc, the flat portion 53 is the light reflecting portion, so the width of the flat portion 53 in the width of the region in the light guide direction D2 corresponds to the reflectivity, and the reflectivity decreases as the distance from the incident portion 5a increases.

[0065] The light guide 5 has a configuration that includes multiple regions 5ba to 5bc with different width ratios, which makes it possible to make the amount of emitted light in each region approximately uniform. For example, if the reflectances of the first region 5ba, the second region 5bb, and the third region 5bc are approximately 67%, 50%, and 0%, respectively, and the amount of incident light incident on the first region 5ba is set to 100%, then on the emission surface 5b, the amount of emitted light in the first region 5ba will be 100%-67%≈33%, the amount of emitted light in the second region 5bb will be 67÷2≈33%, and the amount of emitted light in the third region 5bc will be the remaining approximately 34%, resulting in approximately uniform light output in each region.

[0066] In the above explanation, the case where the number of regions on the emission surface 5b is three was used as a representative example, but this is not the only case, and the number of regions can be changed as appropriate. In this case, the width ratio in each region should be changed as appropriate so that the amount of emitted light is approximately uniform.

[0067] Here, for example, as shown in Figure 13, among the boundaries of regions 5ba to 5bc, the boundary closest to the virtual straight line VL4 connecting region BC1, which is the black visible region of the black ceramic part BC, and the second viewpoint position P2 is defined as boundary B. In this case, it is preferable that the second light-shielding part 42 is positioned and its length adjusted so as to hide not only region BC1 but also boundary B when viewed from the second viewpoint position P2. This reduces the user's discomfort caused by boundary B of regions with different width ratios entering the field of view and improves the visibility of the scene in the blind spot.

[0068] This modified version also provides a blind spot assist device 1 that has the same effects as the third embodiment described above. Furthermore, in this modified version of the blind spot assist device 1, since the emission surface 5b of the light guide 5 is composed of multiple regions 5ba to 5bc with different width ratios, the effect of making the amount of light emitted from the emission surface 5b approximately uniform is also obtained.

[0069] (Other embodiments) This disclosure is described in accordance with the embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the equivalence range. In addition, various combinations and forms, as well as other combinations and forms including one, more, or less of those elements, fall within the scope and concept of this disclosure.

[0070] For example, in the embodiments described above, the second light-shielding portion 42 was described on the premise that it has a uniform thickness, but it is not limited to this. The second light-shielding portion 42 may have a tapered shape, for example, as shown in Figure 14(a), with the end on the ejection surface 2b side being the base portion 421 and the opposite end being the tip portion 422, with the thickness decreasing towards the tip portion 422. In this case, it becomes more difficult for the user to focus on the tip portion 422, making it easier to see the scene in the blind spot area.

[0071] Furthermore, the second light-shielding portion 42 may have a tapered shape, as shown in Figure 14(b), and may also have a curved shape with a radius of curvature of 2 mm or more at the tip portion 422. In this case, in addition to the effect of the tapered shape, the second light-shielding portion 42 also has the effect of preventing injury to the user if they come into contact with the tip portion 422.

[0072] Furthermore, the second light-shielding portion 42 may have a curved shape, such as shown in Figure 14(c), where the entire area from the base portion 421 to the tip portion 422 is curved. Also, although Figure 14 describes other examples of the shape of the second light-shielding portion 42, the multiple first light-shielding portions 41 may similarly have shapes such as tapered shapes, shapes with curved tips, or shapes that are curved overall.

[0073] It goes without saying that, in each of the above embodiments, the elements constituting the embodiment are not necessarily essential unless explicitly stated to be particularly essential or unless they are clearly considered essential in principle. Furthermore, in each of the above embodiments, when numerical values ​​such as the number, numerical values, quantities, or ranges of the components of the embodiment are mentioned, the embodiment is not limited to those specific numbers unless explicitly stated to be particularly essential or unless it is clearly limited to a specific number in principle. Furthermore, in each of the above embodiments, when the shape, positional relationship, etc., of the components are mentioned, the embodiment is not limited to those shapes, positional relationships, etc., unless explicitly stated or unless it is clearly limited to a specific shape, positional relationship, etc., in principle. [Explanation of Symbols]

[0074] 21-23... Region of the light-transmitting reflective member, 2a... Light-transmitting reflective surface of the transparent reflective member, 3a... Reflective surface of the reflective member, 4... Light-shielding member, 41... First light-shielding part, 42... Second light-shielding part, 5... Light guide, 5c... Reflective surface of the light guide, 52... Prism part, 52a... Ejection surface, 53... Flat part, 5b... Light-transmitting reflective surface of the light guide, 5ba-5bc... Region of the light guide, B... Boundary between regions of the light-transmitting reflective member, BC... Black ceramic part (second member), BC1... Light-shielding part, E30... Edge of the reflective member, E5b... End of the reflective surface of the light guide, P... Front pillar (first member), P1... Reference viewpoint position, P2... Second viewpoint position

Claims

1. A blind spot assist device attached to a first member (P) that creates a blind spot area, which allows the image of the blind spot area to be viewed, External light (L1), including light from the blind spot region, is incident on a transmissive reflective surface (2a, 5b) that reflects a portion of the external light and transmits another portion of the external light, A reflective surface (3a, 5c) is positioned opposite to the aforementioned transmissive reflective surface and reflects the light reflected by the transmissive reflective surface back towards the transmissive reflective surface, The device comprises a light-shielding member (4) having a plurality of first light-shielding portions (41) and second light-shielding portions (42) arranged on the opposite side of the reflective surface, with the aforementioned transmissive reflective surface in between, and blocking external light incident on the transmissive reflective surface at a predetermined angle, A portion of the multiple first light-shielding portions is arranged so as to overlap with the incident-side end (E30, E5c0) of the reflective surface or the image of the incident-side end reflected on the reflective surface, when viewed from an arbitrarily determined reference viewpoint position (P1). At least one of the plurality of first light-shielding portions is arranged to overlap with the incident end (E20, E5b) of the transmissive reflective surface when viewed from the reference viewpoint position. The second light-shielding portion is positioned to conceal a light-shielding portion (BC1) of the second member, which is adjacent to the first member, when viewed from a second viewpoint position (P2) located at a predetermined distance from the reference viewpoint position, thereby providing a blind spot assistance device.

2. The aforementioned transmissive reflective surface is composed of a half-mirror. The blind spot assist device according to claim 1, wherein the reflective surface is composed of a mirror positioned opposite to the half-mirror.

3. The aforementioned transmission and reflection surface is divided into multiple regions (21-23, 5ba-5bc), The blind spot assist device according to claim 1, wherein the second light-shielding portion is arranged to conceal one of the boundaries (B) of two adjacent regions of the transmissive reflective surface when viewed from the second viewpoint position.

4. The aforementioned transmissive reflective surface is divided into a plurality of regions (21 to 23), and at least one of the plurality of regions becomes transparent, allowing light to pass through, while other regions different from the transparent region become reflective, allowing light to be reflected, and the region that becomes transparent is sequentially switched by a dimming member. The blind spot assist device according to claim 1 or 3, wherein the reflective surface is composed of a mirror positioned opposite to the dimming member.

5. The aforementioned transmissive reflective surface and the reflective surface are the outer surfaces of a single light guide (5) made of a light-transmitting material. The reflective surface is a flat surface that reflects a portion of the ambient light incident on the inside of the light guide towards the transmitting reflective surface by total internal reflection. The aforementioned transmissive reflective surface is composed of a plurality of protruding prism portions (52) and a plurality of flat portions (53). Each of the prism sections has an emission surface (52a) that emits a portion of the ambient light incident on the light guide to the outside. The blind spot assist device according to claim 1 or 3, wherein the plurality of flat portions reflect a portion of the ambient light incident on the inside of the light guide body towards the reflective surface by total internal reflection.

6. The blind spot assist device according to any one of claims 1 to 3, wherein the second light-shielding portion has a curved shape at the tip (422) which is the end opposite to the transmitted reflective surface, and the radius of curvature of the tip is 2 mm or more.

Images