JP2023174352A - Dead angle auxiliary device - Google Patents

Abstract

To suppress the relative positional deviation of portions that function as a pair of mirrors in an optical member and suppress superimposition of other light on emission light in a dead angle auxiliary device.SOLUTION: An optical member comprises: an incidence surface 2a on which ambient light is incident; an emission surface 2b which has a plurality of emission parts 21 and flat parts 22; and a smooth surface 2c which is arranged so as to be opposed to the plurality of flat parts 22. The optical member 2 is made of a translucent material and reflects incident light by total reflection on the flat parts 22 and the smooth surface 2c. The optical member 2 is attached to a storage part of a holding member 3 and is fixed in such a state that there is a prescribed or greater gap between the smooth surface 2c and a bottom surface 31a of the storage part. A light shielding member 4 is arranged on an end on at least the incidence surface 2a side of the gap between the surface on the smooth surface 2c side of the optical member 2 and the holding member 3.SELECTED DRAWING: Figure 3

Description

The present invention relates to a blind spot auxiliary device using an optical member that internally reflects a portion of light incident from an incident surface and emits the incident light and its reflected light to the outside from a surface different from the incident surface.

Conventionally, examples of this type of optical member include the one described in Patent Document 1, for example. The optical member described in Patent Document 1 is attached to a pillar of a vehicle and used as a part of a blind spot assist device. This optical member includes a half mirror that reflects part of external light while transmitting part of it, and a mirror that reflects light reflected by the half mirror onto the half mirror, and these are held in opposing positions. The vehicle has a case body, and the case body is attached to the vehicle pillar.

When external light enters from the opposite side of the vehicle pillar, this optical member is repeatedly reflected between a pair of mirrors consisting of a mirror and a half mirror, and is placed on the opposite side of the vehicle pillar. It is configured so that the light is transmitted through the half mirror. Thereby, the blind spot assisting device is capable of visually confirming the outside view of the blind spot area hidden by the vehicle pillar through the optical member.

Japanese Patent Application Publication No. 2015-147496

However, since this optical member has a mirror and a half mirror as separate members, if their relative positions shift, the position of the external scene due to the light transmitted from the half mirror, that is, the position of the external scene as seen by the user through the optical member, may change. The position of the outside scenery deviates from the actual situation. In order to prevent such a situation, a casing that holds the pair of mirrors so that their relative positions do not shift, and a fixing member that fixes the casing and the pair of mirrors are required. In addition, the configuration for suppressing misalignment of the relative positions of the pair of mirrors requires a large number of parts, and assembly to other members such as vehicle body pillars is complicated and requires high precision.

Through extensive research, the present inventors devised a new optical member composed of a single member, which is capable of internally guiding incident external light using a light-guiding material and utilizing total internal reflection. However, a new blind spot assisting device has been created in which this optical member is held and fixed to other members such as vehicle pillars. This new blind spot auxiliary device is a single optical member that does not have two separate mirrors, so there is no deviation in the relative position of the pair of mirrors, and the difference between the position of the outside scene and the actual situation due to this does not occur. Discrepancies with the scene are suppressed.

Since this new blind spot auxiliary device has an optical member that utilizes total reflection, it is necessary to provide a predetermined gap between the holding member and the light reflecting surface. However, as a result of further study by the present inventors, external light enters the gap between the optical member and the holding member, causing unintended light to be superimposed on the light emitted to the outside from the exit surface of the optical member. found.

In view of the above points, the present invention provides an optical member that does not cause a relative positional shift between two surfaces: an exit surface that causes reflection and transmission of incident external scene light and a reflective surface that reflects the incident external scene light to the exit surface. The objective is to suppress unintended superimposition of light in a blind spot assist device using

In order to achieve the above object, the blind spot auxiliary device according to claim 1 has an entrance surface (2a, 23a) on which outside scene light enters, a plurality of emission parts (21) and a plurality of flat parts (22). , has an exit surface (2b) where the incident light incident from the entrance surface reaches first, and a smooth surface (2c) arranged opposite to a plurality of flat parts, and is made of a translucent material. It has an optical member (2) and a housing part (31) in which the optical member is stored, and a holding member (3) that holds the optical member, and a surface of the housing part facing the smooth surface of the optical member is a bottom surface (31a). ), a light shielding member (4) disposed at least at the end on the incident surface side of the gap between the smooth surface of the optical member and the bottom surface of the housing part, and the plurality of flat parts block the incident light. It is a first reflecting surface that reflects toward a smooth surface by total reflection, and the smooth surface is a second reflecting surface that reflects reflected light from a flat part to an exit surface by total reflection. emits part of the incident light or part of the light reflected by the smooth surface to the outside on the side opposite to the holding member.

This blind spot auxiliary device uses an optical member that is a single member made of a translucent material, and a part of the external light that enters from the incident surface of the optical member is totally reflected on flat and smooth surfaces. At the same time as being reflected, a part of the incident external scene light is emitted to the outside from the emitting part. This blind spot auxiliary device does not cause any relative positional deviation between the flat part of the optical member that functions as a pair of mirrors and the smooth surface, so it requires fewer components than before, making it easier to assemble the optical member to the holding member. It also has a simple structure. In addition, a light shielding member is placed at the end of the entrance surface side of the gap between the smooth surface of the optical member and the bottom surface of the housing part of the holding member to prevent light from entering from the entrance surface side. Unnecessary outside light is not incident, and unintended outside light is not superimposed on the light emitted from the exit surface.

Note that the reference numerals in parentheses attached to each component etc. indicate an example of the correspondence between the component etc. and specific components etc. described in the embodiments to be described later.

FIG. 1 is a perspective view of a blind spot assisting device according to a first embodiment. It is a perspective exploded view of the blind spot assist device of a 1st embodiment. FIG. 2 is a diagram corresponding to a cross-sectional view taken along line III-III in FIG. 1, showing the arrangement of light shielding members and the shielding of external light by the light shielding members. 2 is a sectional view taken along line IV-IV in FIG. 1. FIG. FIG. 3 is a perspective view of the optical member seen from another angle. 6 is a sectional view taken along line VI-VI in FIG. 5. FIG. It is an explanatory view for explaining light guide in the blind spot assistance device of a 1st embodiment. FIG. 7 is an explanatory diagram for explaining the superposition of emitted light and unintended external scene light in a blind spot assisting device of a comparative example that does not have a light shielding member. It is a sectional view showing a blind spot assistance device concerning a modification of a 1st embodiment. FIG. 4 is a cross-sectional view corresponding to FIG. 3 and showing a blind spot assisting device according to a second embodiment. FIG. 7 is an explanatory diagram for explaining light guide in the blind spot assisting device of the second embodiment. It is a figure corresponding to FIG. 3, and is a sectional view showing a blind spot assisting device of a third embodiment. FIG. 7 is a diagram corresponding to FIG. 6 and a cross-sectional view showing an optical member according to a third embodiment. FIG. 7 is an explanatory diagram for explaining light guiding in a blind spot assisting device according to a third embodiment. It is a perspective view showing an optical member concerning a blind spot assistance device of a 4th embodiment. FIG. 7 is a diagram corresponding to FIG. 6 and a cross-sectional view showing a configuration example of another optical member. FIG. 7 is a diagram corresponding to FIG. 6 and a cross-sectional view showing a configuration example of another optical member. FIG. 7 is a diagram corresponding to FIG. 6 and a cross-sectional view showing a configuration example of another optical member. FIG. 7 is a diagram corresponding to FIG. 6 and a cross-sectional view showing a configuration example of another optical member.

Embodiments of the present invention will be described below based on the drawings. Note that in each of the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
A blind spot assisting device 1 according to a first embodiment will be described with reference to the drawings.

In FIGS. 1 and 2, a part of the invisible outer shell of the holding member 3, which will be described later, is shown by a broken line. Hereinafter, for convenience of explanation, as shown in FIG. 1, the direction of the holding member 3 along the light guiding direction of the optical member 2, which will be described later, will be referred to as a "first direction D1," and the upper surface 2e of the optical member 2, which will be described later, will be referred to as a "first direction D1." The direction along the direction connecting the lower surface 2f is referred to as a "second direction D2." D1 and D2 shown in the figures after FIG. 2 are directions corresponding to D1 and D2 shown in FIG. 1.

The blind spot assist device 1 of this embodiment includes an optical member 2, a holding member 3 having a housing portion 31, and a light shielding member 4, as shown in FIGS. 1 and 2, for example. As shown in FIGS. 3 and 4, for example, the blind spot assisting device 1 has an optical member 2 attached to a housing portion 31 of a holding member 3, and a light shielding member 4 at one end of the gap between the optical member 2 and the holding member 3. It will be placed. The blind spot auxiliary device 1 has a configuration in which external light from the blind spot area is guided by the holding member 3 inside the optical member 2 and emitted to the user side, thereby allowing the user to visually recognize the blind spot area. The blind spot assisting device 1 is preferably applied to an in-vehicle application in which the holding member 3 is a pillar that obstructs the driver's view of a vehicle such as a car, and the blind spot area is made visible to the driver. Of course, it can also be applied to blind spot assistance in other applications. In this specification, a case where the blind spot assist device 1 is installed in a vehicle will be described as a representative example.

For example, as shown in FIG. 5, the optical member 2 includes an entrance surface 2a, a smooth surface 2c adjacent to the entrance surface 2a, an exit surface 2b opposite to the smooth surface 2c, and a terminal end surface 2d opposite to the entrance surface 2a. It is a light guide having. The optical member 2 has an upper surface 2e and a lower surface 2f, which are surfaces that connect the exit surface 2b and the smooth surface 2c, and also connect the entrance surface 2a and the terminal end surface 2d. The optical member 2 is a single member whose base is made of a translucent material, and when a user views the optical member 2 alone from the exit surface 2b side in a situation where there is no light incident on the entrance surface 2a, It is a light guide that allows the sight on the smooth surface 2c side to be visually recognized. As the light-transmitting material, for example, a resin material such as polyethylene terephthalate, polycarbonate, polyethylene, or acrylic, or an inorganic material such as glass can be used. The optical member 2 does not have a mirror or a half mirror made of a reflective material with a reflectance higher than a predetermined value, and guides the incident light by totally reflecting it on a surface made of a translucent material. is designed to. Note that, in this embodiment, the base of the optical member 2 means a portion excluding the light absorption film 211, which will be described later.

In this embodiment, the optical member 2 is fixed to the holding member 3 by being fitted into the accommodating portion 31 of the holding member 3, as shown in FIG. 4, for example. The optical member 2 is held by the holding member 3 with the smooth surface 2c facing the accommodating portion 31 and the exit surface 2b facing in the opposite direction to the holding member 3. The optical member 2 is fixed with a gap D ₀ of a predetermined value or more (for example, but not limited to, 1 mm or more) between the smooth surface 2 c and the bottom surface 31 a of the housing part 31 , and the entire smooth surface 2 c is A reflective state can be ensured. The optical member 2 is attached to the holding member 3 so that the entrance surface 2a and the terminal end surface 2d are each located near the end of the bottom surface 31a of the housing portion 31 in the first direction D1.

As shown in FIG. 6, for example, the optical member 2 has an exit surface 2b having a plurality of exit parts 21 and flat parts 22, which are arranged alternately and repeatedly. For example, as shown in FIG. 7, the optical member 2 allows external scene light to enter the interior from an entrance surface 2a, repeatedly reflects the incident light on an exit surface 2b and a smooth surface 2c, and rejects some light from the exit surface 2b. By emitting the image to the outside, the user on the side of the emission surface 2b can see the external scenery.

For convenience of explanation, for example _, as shown in _FIG . The light incident on the light source L 2 is sometimes referred to as "incident light L ₂ ". Moreover, the light emitted from the exit surface _2b to the outside of the optical member 2 out of the incident light L 2 may be referred to as "emitted light L ₃ ".

For example, as shown in FIG. 7, the optical member 2 totally reflects the incident light _L2 at the flat portion 22 and the smooth surface 2c of the exit surface 2b, which are made of a light-transmitting material. It is designed to satisfy the following.

sinφ≧n ₂ /n ₁ ...(1)
In equation (1), n ₁ is the refractive index of the optical member 2, and n ₂ is the refractive index of the external medium (for example, air). Further, φ is the angle of incidence of the incident light _L2 on the flat portion 22, and the normal direction to the plane formed by the flat portion 22 or the smooth surface 2c (hereinafter simply referred to as "normal direction") and the incident light This is the angle formed with the traveling direction of _L2 . As a result, even if the optical member 2 does not have a semi-transmissive mirror or a mirror made of a reflective material such as metal, a portion of the incident light _L2 from the incident surface 2a is transmitted to the flat portion 22 and the smooth surface 2c. It is configured to be totally reflected and emitted to the outside from the exit surface 2b. Note that it is preferable that the inclination angle ψ of the incident surface 2a with respect to the normal direction is smaller than the incident angle φ of the incident light _L2 , that is, the light guiding angle. Further, θ ₁ in FIG. 7 is the incident angle of the outside scene light L ₁ , and is the angle between the traveling direction of the outside scene light L ₁ and the normal direction.

The exit surface 2b is the surface on which the incident light _L2 from the entrance surface 2a reaches first. The injection surface 2b is, for example, a triangular protrusion in cross-sectional view, and a plurality of injection parts 21 that are similar to each other are arranged in parallel with a flat part 22 in between. The emission part 21 of the emission surface 2b is a part that emits the incident light _L2 to the outside. The flat portion 22 of the exit surface 2b is a first reflecting surface that reflects the incident light _L2 toward the smooth surface 2c by total internal reflection. As a result, the optical member 2 can guide the incident light _L2 internally without having a semi-transmissive mirror made of a metal material or a dielectric material, and can also absorb the incident light _L2 in the flat portion 22. The structure is such that no loss occurs.

Here, one virtual plane formed by the plurality of flat parts 22 is defined as a flat surface, the direction along the flat surface from the incident surface 2a toward the terminal surface 2d is defined as the light guiding direction, and the width in the light guiding direction is defined as _W22 . . At this time, the plurality of flat portions 22 have a width _W22 such that the reflectance of the incident light _L2 on the exit surface 2b is equal to or greater than a predetermined value. Specifically, since the plurality of flat portions 22 of the exit surface 2b are reflection portions of the incident light _L2 , and the plurality of exit portions 21 are absorption portions and exit portions of the incident light _L2 , the reflection of the exit surface 2b is The rate _RW is determined by the proportion of the flat portion 22. The reflectance R _W of the exit surface 2b is expressed by the following equation (2), where W ₂₁ is the width in the light guiding direction of the exit section 21 adjacent to the flat portion 22 having a width W ₂₂ .

R _W = W ₂₂ / (W ₂₁ + W ₂₂ )...(2)
The plurality of flat portions 22 may have a width that satisfies R _W ≧0.5, that is, a width W ₂₂ such that the reflection of the incident light L ₂ on the exit surface 2b is greater than the emission, that is, W ₂₁ /W ₂₂ ≦1. preferable. In this case, the optical member 2 guides more than half of the incident light _L2 at the exit surface 2b, and emits the exit light _L3 over a wider range of the exit surface 2b, reducing the brightness of the exit light _L3 . It becomes possible to secure it.

Further, when the optical member 2 satisfies the above equation (1) and the incident angle φ is the total reflection angle, the reflectance _RW at the exit surface 2b is as shown in the above equation (2), and the width of the flat portion 22. In other words, since the reflectance _RW of the optical member 2 does not depend on the angle or wavelength of the incident light _L2 , the optical member 2 has a higher color tone of the emitted light _L3 than a conventional optical member using a semi-transmissive mirror. The effect of suppressing changes in brightness can be obtained.

As shown in FIG. 7, for example, the plurality of injection parts 21 have a first surface 21a and a second surface 21b that faces the first surface 21a and intersects with the first surface 21a. The first surface 21a is adjacent to the flat portion 22, and is a surface that emits part of the incident light _L2 to the outside. The first surface 21a is, for example, approximately parallel to the entrance surface 2a. When the first surface 21a is parallel to the incident surface 2a, the exit angle θ ₂ of the outgoing light L ₃ from the first surface 21 a is the same as the incident angle θ ₁ , so the optical member 2 The same light beam as ₁ can be made visible to the user on the side of the exit surface 2b.

Note that the exit angle θ ₂ of the exit light L ₃ is the angle between the traveling direction of the exit light L ₃ and the normal direction. In addition, "substantially parallel" means that the entrance surface 2a and the first surface 21a are approximately parallel due to unavoidable errors due to the processing accuracy of the optical member 2. Including cases where they are parallel. "Substantially parallel" in the following specification has the same meaning.

The second surface 21b of the plurality of injection parts 21 is inclined at an inclination angle δ with respect to the normal direction. The second surface 21b is preferably covered with a light absorption film 211, for example, from the viewpoint of suppressing the reflection of the incident light _L2 on the second surface 21b and the intrusion of external light from the exit surface 2b side. As a result, a ghost appears due to external light from the exit surface 2b side being superimposed on the exit light L ₃ , and an unintended reflected light of the incident light L ₂ on the second surface 21b is emitted from the first surface 21a. Noise can be suppressed. The light absorption film 211 is made of any light-shielding resin material, metal material, or the like, and is formed by any process such as printing or vapor deposition.

The inclination angle δ of the second surface 21b is greater than or equal to the exit angle θ ₂ of the emitted light L ₃ , and is greater than or equal to the incident angle θ _{1 of the external scene light L 1} when the incident surface 2 a and the first surface ₂₁ a are parallel. Thereby, the emitted light _L3 is emitted to the outside without being blocked by the second surface 21b. Further, it is preferable that the second surface 21b has an inclination angle δ smaller than an incident angle φ (light guiding angle) of the incident light L ₂ on the flat portion 22 . This prevents the incident light L ₂ from entering and interfering with the second surface 21b, and suppresses unintended reflection of the incident light L ₂ on the second surface 21b and noise resulting from this.

Note that when the width W ₂₁ of the plurality of emission parts 21 and the width W 22 of the plurality of flat parts ₂₂ are all the same, a gap corresponding to the width W ₂₁ is created in the reflected light beam, and the gap and the subsequent part of the emission part are the same. Periodic changes in the relationship with 21 may cause uneven brightness, that is, moiré. From the viewpoint of suppressing such moiré, it is preferable that W ₂₁ and W ₂₂ have values within a predetermined range centered around a certain value, that is, have a distribution.

The smooth surface 2c is a second reflective surface that reflects the incident light _L2 reflected by the flat portion 22 toward the exit surface 2b by total internal reflection. In other words, the smooth surface 2c is an optical surface that is substantially parallel to the flat portion 22 and functions together with the flat portion 22 as a pair of mirrors. Therefore, the incident light _L2 from the incident surface 2a is repeatedly incident and reflected at the incident angle φ on the flat portion 22 and the smooth surface 2c, and is emitted from the entire area of the exit surface 2b while traveling along the light guide direction. It is ejected from the section 21 to the outside. The remaining part of the incident light _L2 is finally emitted to the outside from the terminal end surface 2d.

The terminal end surface 2d is a surface connecting the exit surface 2b and the smooth surface 2c on the opposite side to the entrance surface 2a, and is located at a position facing the entrance surface 2a, that is, at the end in the light guiding direction. For example, as shown in FIG. 6, the terminal surface 2d is the first surface 21a of the injection section 21 (hereinafter referred to as "terminal injection section") located at the end of the plurality of injection sections 21 on the opposite side to the entrance surface 2a. It is assumed that the slope intersects with Note that the terminal surface 2d is not limited to the configuration shown in FIG. 6, and may be configured to form one surface together with the first surface 21a of the terminal injection portion 21, or may be continuous with the holding member 3 described later. The slope may be adjusted to form a curved surface. In the former case, the termination surface 2d is substantially parallel to the entrance surface 2a.

The upper surface 2e and the lower surface 2f are non-optical surfaces that are not used for reflecting the incident light _L2 . The width of the optical member 2 in the direction connecting the upper surface 2e and the lower surface 2f is approximately the same as the width of the accommodating portion 31 of the holding member 3 in the second direction D2. The optical member 2 is configured such that an upper surface 2e and a lower surface 2f are fitted into and fixed to the holding member 3.

The holding member 3 is a member to which the optical member 2 is attached, and in the case of in-vehicle use, it may be a vehicle body pillar such as an A pillar, or a pillar cover that covers the vehicle body pillar. The holding member 3 has a housing portion 31 in which the optical member 2 is housed, as shown in FIG. 2, for example. When the optical member 2 is attached to the holding member 3, the bottom surface 31a of the accommodating portion 31 is connected to the smooth surface 2c of the optical member 2, and the side wall surface 31b adjacent to the bottom surface 31a is connected to the upper surface 2e and lower surface 2f of the optical member 2, respectively. opposite. In the holding member 3, a part of the side wall surface 31b protrudes outward from the bottom surface 31a in the first direction D1. A portion of the side wall surface 31b that protrudes outward from the bottom surface 31a is defined as a protruding portion 31ba, and the protruding portion 31ba covers a predetermined region of the upper surface 2e and lower surface 2f of the optical member 2 on the side of the entrance surface 2a.

The light shielding member 4 is disposed at least at the end of the gap between the optical member 2 and the holding member 3 on the side of the entrance surface 2a, and is a member for closing part of the gap and blocking light. The light shielding member 4 is made of, for example, an elastic body such as rubber, resin, or silicone. Further, the light shielding member 4 is a light absorber partially or entirely made of a light absorbing material. For example, the width of the portion of the light shielding member 4 in contact with the smooth surface 2c may be set to be less than a predetermined value (for example, 1 mm or less, although it is not limited) so as not to impede internal total reflection on the smooth surface 2c as much as possible. preferable.

The light shielding member 4 is bonded to the optical member 2 with an optical adhesive (not shown) such as OCA or OCR, or is bonded to the holding member 3 with an arbitrary adhesive, so that it is not attached to the optical member 2 or the holding member 3. be integrated. OCA is an abbreviation for Optical Clear Adhesive, and OCR is an abbreviation for Optical Clear Resin. For example, as shown in FIG. 3, the light shielding member 4 secures a predetermined gap or more between the smooth surface 2c and the bottom surface 31a of the accommodating part 31 when the optical member 2 is attached to the accommodating part 31 of the holding member 3. At the same time, unintended light _L11 from the incident surface 2a side is prevented from entering the smooth surface 2c. That is, the light shielding member 4 functions not only as a light shielding member but also as a positioning member with respect to the holding member 3. Thereby, while ensuring total reflection inside the smooth surface 2c, it is possible to suppress the unintended light _L11 from being superimposed on the emitted light _L3 emitted from the exit surface 2b and obstructing the visibility of the external scenery.

Specifically, as shown in FIG. 8, for example, in the case of the blind spot assisting device 100 of the comparative example that does not include the light shielding member 4, the optical member 2 allows the outside light _L1 to enter the incident surface 2a, and the holding member 3 Unintended light _L11 also enters the gap between the two. Then, the incident light L ₂ and the incident unintended light L ₁₁ enter the inside of the optical member 2, and these lights are emitted from the first surface 21a of the emitting portion 21. As a result, the emitted light L ₃ and the unintended light L ₁₁ are superimposed on each other from the exit surface 2b, and visibility of the external scenery at the exit surface 2b is hindered. As described above, although the blind spot assisting device 100 of the comparative example has a new configuration using the optical member 2 composed of a single member, it is difficult to visually recognize the external scenery at the exit surface 2b due to the above-mentioned superposition of light. Disturbances may arise.

On the other hand, in the blind spot assisting device 1 of the present embodiment, the light shielding member 4 is disposed at the end of the gap between the optical member 2 and the holding member 3 on the side of the entrance surface 2a. Unintended light _L11 from the outside does not enter the smooth surface 2c. This suppresses the unintended light L11 from being superimposed on the emitted light _L3 from the emitting surface 2b, and it is possible to ensure the visibility of the external scene on the emitting surface 2b.

In the blind spot assisting device 1 of this embodiment, the optical member 2 that guides the incident light _L2 is composed of a single member, and includes an exit surface 2b that reflects the incident light _L2 and emits it to the outside. There is no displacement of the smooth surface 2c that reflects the incident light _L2 , that is, the portions that function as a pair of mirrors. In addition, the blind spot assisting device 1 does not require a fixing member for suppressing a shift in the relative position of the portions of the optical member 2 that function as a pair of mirrors, and has fewer parts compared to the conventional one. Does not require precision in assembly. Further, in the blind spot assisting device 1, a gap larger than a predetermined value is provided between the optical member 2 and the holding member 3, and total reflection on the smooth surface 2c can be ensured. In addition, the blind spot assist device 1 prevents unintentional light from entering the smooth surface 2c from the outside with the light shielding member 4, so that the superimposition of other unintended light on the emitted light _L3 is suppressed, and the emitted light L3 is suppressed. The visibility of the external scenery on the surface 2b can be ensured.

(Modified example of the first embodiment)
For example, as shown in FIG. 9, the blind spot assisting device 1 has a configuration in which a light shielding member 4 is arranged not only at the end of the smooth surface 2c on the entrance surface 2a side but also at the end on the terminal surface 2d side. Good too. Thereby, the blind spot auxiliary device 1 has a configuration in which unintended light L ₁₁ from the outside on the end surface 2 d side does not enter the smooth surface 2 c of the optical member 2 .

According to this modification, in addition to the effects of the first embodiment, the unintended light _L11 from the outside on the terminal surface 2d side is no longer superimposed on the emitted light _L3 , and the visibility of the external scene at the exit surface 2b is improved. The blind spot assisting device 1 can also provide improved effects.

(Second embodiment)
A blind spot assisting device 1 according to a second embodiment will be described. Although FIG. 11 does not show a cross section in order to make it easier to understand the light guide in the optical member 2 according to the present embodiment, the external light L ₁ , the incident light L ₂ , L ₂₁ , L ₂₂ and the exit light L ₃ are shown in FIG. Has hatching.

In the blind spot assisting device 1 of this embodiment, as shown in FIG. 10, for example, the entrance surface 2a of the optical member 2 protrudes beyond the smooth surface 2c in the thickness direction of the optical member 2, and a part of the exit surface 2b This embodiment differs from the first embodiment in that the injection region 2b1 is composed of only the injection section 21. In this embodiment, this difference will be mainly explained.

In the optical member 2, in this embodiment, the entrance surface 2a protrudes from the smooth surface 2c in the thickness direction, and the surface of the portion of the entrance surface 2a that protrudes from the smooth surface 2c is adjacent to the smooth surface 2c. It has an inclined surface 2g that is inclined toward the surface. In other words, the optical member 2 has a configuration in which the entrance surface 2a is a part of one large prism section, and has a thickness partially greater than the thickness between the smooth surface 2c and the flat portion 22. . For example, like the second surface 21b of the emission part 21, the inclined surface 2g has a light absorption film 211 formed thereon, and is a surface on which the external scene light _L1 does not enter.

In this embodiment, the optical member 2 has a larger area of the entrance surface 2a than in the first embodiment, so the area of the part of the exit surface 2b where the incident light _L2 from the entrance surface 2a first reaches. is getting wider. The optical member 2 is capable of guiding more light, and has a configuration that does not create a gap in light guiding. The "light guiding gap" here refers to a state in which there is an exit part 21 on the exit surface 2b where the incident light _L2 does not reach, that is, an exit part 21 that does not emit the emitted light _L3 to the outside. It means the gap in the light guiding direction between the adjacent emitted light beams _L3 with the non-emitting emitting part 21 in between. In other words, the exit surface 2b is in a state in which all the plurality of exit parts 21 emit the emitted light _L3 , and no gap is created in the external view visually recognized by the user.

In the optical member 2, in this embodiment, a part of the exit surface 2b from the end on the terminal surface 2d side is an exit region 2b1 that is made up of only a plurality of exit sections 21. The emission region 2b1 is a region where the incident light _L2 reflected by the smooth surface 2c is not reflected, and the emitted light _L3 is mainly emitted from the first surface 21a to the outside.

Here, as shown in FIG. 11, for example, the width in the light guiding direction of the optical member 2 of the portion of the exit surface 2b where the incident light L ₂ from the entrance surface 2a first reaches is defined as _La . Further, the width of the optical member 2 in the light guiding direction from the end of the entrance surface 2a on the exit surface 2b side to the end of the smooth surface 2c on the termination surface 2d side is defined as _Lb. At this time, it is preferable that the optical member 2 has a configuration that satisfies the following formulas (3) and (4).

L _a = (2N-1) x T ₀ x tanφ... (3)
L _b =2N×T ₀ ×tanφ...(4)
N in equations (3) and (4) is a positive integer. When the optical member 2 satisfies formulas (3) and (4), the end of the incident light L ₂ (L ₂₂ in FIG. 11) that reaches the smooth surface 2c due to repeated reflections on the exit surface 2b is the upper end of the termination surface 2d. will match. As a result, only the light rays reflected by the smooth surface 2c are incident on the terminal end surface 2d, while the light rays reflected by the flat part 22 of the exit surface 2b are not incident thereon. In other words, the light emitted from the terminal end surface 2d is emitted only to the exit surface 2b side, and is not emitted to the smooth surface 2c side. Therefore, the optical member 2 can emit guided light in the user's viewing direction without waste.

In addition to satisfying the above formula, by setting the portion of the exit surface 2b that exceeds _La as the exit region 2b1, all of the incident light _L2 that has reached the exit region 2b1 is emitted in the user's viewing direction. be able to. In other words, the number of emitting sections 21 in the portion exceeding _La can be minimized, and the length of the optical member 2 in the light guiding direction can be reduced.

Note that L _a may be within the range of ±10% of the value expressed by (2N-1)×T ₀ ×tanφ. Further, L _b may be within the range of ±10% of the value expressed by 2N×T ₀ ×tanφ. This is because a deviation of about 10% may occur due to the angle of incident light, and if L _a and L _b are within the above ranges, it is expected that the loss of light guide can be minimized.

In this embodiment, the light shielding member 4 is disposed, for example, in a portion of the gap between the optical member 2 and the accommodating portion 31 located on the inclined surface 2g and an end portion on the terminal surface 2d side. It may be arranged only in the part located above 2g. In this embodiment as well, the light shielding member 4 disposed on the portion located on the inclined surface 2g can prevent unintended external light, that is, light _L11 , from entering the smooth surface 2c, and unnecessary It is possible to suppress the light _L11 from being superimposed. In addition, in this embodiment, the "end part on the entrance surface 2a side" of the gap between the optical member 2 and the holding member 3 means a region closer to the entrance surface 2a than the smooth surface 2c. Moreover, since the part of the light shielding member 4 that comes into contact with the inclined surface 2g does not come into contact with the smooth surface 2c, its width is arbitrary. Further, the light shielding member 4 that comes into contact with the sloped surface 2g only needs to be able to block unintended light _L11 from reaching the smooth surface 2c, and the arrangement and height of the sloped surface 2g in the first direction D1 should be considered. may be changed as appropriate.

According to this embodiment, in addition to the effects of the first embodiment, the incident light _L2 on the entrance surface 2a of the optical member 2 can be guided to the exit surface 2b and the termination surface 2d without waste, and loss of light rays can be reduced. The blind spot auxiliary device 1 provides the minimum effect. In addition, when the optical member 2 has a configuration that satisfies the above formulas (3) and (4), the area of the emission region 2b1 can be minimized while minimizing the loss of light rays, and the length in the light guide direction can be minimized. In addition, the effect of reducing manufacturing costs can also be obtained.

(Third embodiment)
A blind spot assisting device 1 according to a third embodiment will be described. In FIG. 14, like FIG. 11, although a cross section is not shown, the outside light _L1 , the incident light _L2 , and the emitted light _L3 are hatched.

In the blind spot auxiliary device 1 of this embodiment, for example, as shown in FIG. 12, the optical member 2 has an entrance section 2h formed by a plurality of prism sections 23 on a plane formed by a smooth surface 2c instead of the entrance surface 2a. However, it is configured to have an entrance side surface 2i that connects the entrance section 2h and the exit surface 2b. The blind spot assist device 1 differs from the first embodiment described above in this point. In this embodiment, this difference will be mainly explained.

In this embodiment, the optical member 2 is configured to have an entrance portion 2h arranged on a plane formed by a smooth surface 2c instead of the entrance surface 2a, as shown in FIGS. 12 and 13, for example. The optical member 2 further includes an entrance side surface 2i that connects the entrance section 2h and the exit surface 2b, and is fixed to the holding member 3 with the entrance section 2h protruding outward from the housing section 31.

The entrance portion 2h is formed by repeatedly and continuously arranging a plurality of prism portions 23 having mutually similar shapes in the same direction. The plurality of prism portions 23 have, for example, a triangular shape when viewed in cross section, and one surface of the outer surface opposite to the smooth surface 2c serves as an entrance surface 23a through which a portion of the external scene light _L1 is incident inside. There is. The plurality of prism sections 23 are arranged, for example, so that their respective incident surfaces 23a are substantially parallel. Among the outer surfaces of the plurality of prism portions 23, the surface on the smooth surface 2c side is an adjacent surface 23b. In each of the plurality of prism sections 23, the inclination angle of the adjacent surface 23b is set to be less than or equal to a predetermined value so as not to impede the incidence of the external scene light _L1 onto the entrance surface 23a of the other adjacent prism section 23.

In the incident portion 2h, each of the valley portions, which are contact points between the incident surface 23a and the adjacent surface 23b of the adjacent prism portions 23, are located on the plane formed by the smooth surface 2c. That is, in the incident part 2h, as shown in FIG. 14, for example, in each of the prism parts 23, the optical path length of the incident light _L2 from the incident surface 23a to the flat part 22 of the exit surface 2b is approximately the same. The structure is as follows. Thereby, an effect can be obtained in which the distortion of the external scene image visually recognized by the user is minimized by the emitted light _L3 emitted from the emitting part 21, which will be described later, of the emitting surface 2b.

In order to prevent the incident light L ₂ from being emitted from the incident side surface 2 i to the outside, the incident side surface 2 i has an angle of incidence equal to or greater than the incident angle φ, where the incident angle of the incident light L ₂ to the flat portion 22 is φ. is preferred.

For example, as shown in FIG. 14, the optical member 2 has the following formula, where the height in the normal direction between the flat part 22 and the smooth surface 2c is _T0 , and the width of the incident part 2h in the light guide direction is _W2a . It is preferable that the design satisfies the formula 5).

W _2a = 2T ₀ ×tanφ...(5)
In the case of W _2a = 2T ₀ ×tanφ, for example, as shown _in FIG. , the configuration is such that the reflected light from the area reaches only the smooth surface 2c. As a result, there is no gap between the light guides L ₃ separated by the plurality of light emitting portions 21 and the flat portion 22 from the light emitting surface 2b, and the loss of light rays from the light incident portion 2h is suppressed. . In addition, "ray loss from the incidence part 2h" means the loss of light rays caused by the incident light _L2 reflected by the flat part 22 reaching the incidence part 2h again and being emitted from the incidence part 2h to the outside. do.

Incidentally, since a deviation of about 10% may occur due to the angle of the incident light, if W _I is within the range of ±10% of the value expressed by 2T ₀ × tanφ, the optical member 2 will be This is a configuration in which the influence of gaps between the two is reduced.

In the present embodiment, the light shielding member 4 is disposed, for example, at the end of the gap between the bottom surface 31a and the smooth surface 2c of the accommodating section 31 on the entrance section 2h side and at the end on the termination surface 2d side. However, it may be arranged only at the end on the side of the incident part 2h.

According to this embodiment, in addition to the effects of the first embodiment, the optical path lengths from the entrance surface 23a to the exit surface 2b of the plurality of prism sections 23 constituting the entrance section 2h are approximately the same, so that the user can The blind spot auxiliary device 1 can also achieve the effect of minimizing distortion of the external scene image visually recognized at 2b.

(Fourth embodiment)
A blind spot assist device 1 according to a fourth embodiment will be described with reference to FIG. 15. In FIG. 15, the outline of a part of the optical member 2 is shown by a broken line.

The blind spot auxiliary device 1 of this embodiment differs from the first embodiment in that a light shielding film 5 is formed on a portion of the upper surface 2e and lower surface 2f, which are not optical surfaces, of the optical member 2, as shown in FIG. 15, for example. It differs from In this embodiment, this difference will be mainly explained.

In the present embodiment, the optical member 2 has, for example, each end region of the upper surface 2e and the lower surface 2f on the entrance surface 2a side and the termination surface 2d side covered with the light shielding film 5. The light-shielding film 5 is a thin film of about 10 micrometers made of any light-absorbing material such as black paint, and is formed by spray coating or the like. Thereby, the optical member 2 can suppress unintentional external scene light from entering from the upper surface 2e and lower surface 2f and unintended reflection from the upper surface 2e and the lower surface 2f inside, thereby preventing noise from appearing in the external scenery visible from the exit surface 2b side. The configuration is such that it does not occur. Note that the light shielding film 5 may be formed over the entire upper surface 2e and lower surface 2f. The light-shielding film 5 may have a thickness and material that blocks unintended external light that is about to enter the upper surface 2e and lower surface 2f of the optical member 2, and does not interfere with attaching the optical member 2 to the holding member 3. The thickness, material, etc. may be changed as appropriate.

According to the present embodiment, in addition to the effects of the first embodiment, it is possible to suppress noise caused by unintended incidence of outside scene light from the upper surface 2e and the lower surface 2f, and the visibility of the outside scene at the exit surface 2b is further improved. The blind spot auxiliary device 1 provides improved effects.

(Other embodiments)
Although the present disclosure has been described based on examples, it is understood that the present disclosure is not limited to the examples or structures. The present disclosure also includes various modifications and equivalent modifications. In addition, various combinations and configurations, as well as other combinations and configurations that include only one, more, or less of these elements, fall within the scope and spirit of the present disclosure.

(1) As shown in FIG. 16, for example, the optical member 2 may have a substantially trapezoidal shape in cross-section, except for one of the plurality of emitting portions 21 located at the end on the incident surface 2a side. The first surface 21a and the second surface 21b of the plurality of injection sections 21 are not adjacent to each other, except for some injection sections 21, and the tip surface thereof is a flat surface connecting the first surface 21a and the second surface 21b. It has a third surface 21c.

In the emission part 21 having the third surface 21c, the light absorption film 211 is formed not on the second surface 21b but on the third surface 21c. As a result, even if the incident light L2 enters the second surface 21b and unintended reflection occurs, the unintended reflected light is blocked by the light absorption film 211 formed on the third surface 21c, and the light is emitted from the exit surface 2b. It will no longer be ejected. As a result, the effect of suppressing the unintended reflected light on the second surface 21b from being superimposed on the emitted light _L3 emitted to the outside from the first surface 21a and the generation of noise can be obtained.

(2) The optical member 2 may have a configuration in which the exit surface 2b is divided into a plurality of regions, and the intervals between the exit portions 21 are different for each divided region, as shown in FIG. 17, for example. In this case, for example, the exit surface 2b is divided into three regions, a first region 2ba, a second region 2bb, and a third region 2bc, along the light guide direction from the entrance surface 2a side, and the region closer to the terminal surface 2d side is The interval between the sections 21 is reduced. Specifically, the ratio of _the width W 21 of the injection part 21 to the width W ₂₃ of the flat part 22 is larger in the second region 2bb than in the first region 2ba. The third region 2bc is made up of only the injection part 21.

More specifically, the reflectance R _W inside the exit surface 2b expressed as W ₂₂ /W ₂₁ is, for example, 2/3 in the first region 2ba, 1/2 in the second region 2bb, and 1/2 in the third region. It is set to 0 in 2bc. In this case, assuming that the incident light _L2 from the incident surface 2a is 100%, the first region 2ba reflects about 67%, which is equivalent to 2/3 of the incident light _L2 , onto the smooth surface 2c, and the remaining about 33%. is injected from the injection section 21 to the outside. The second region 2bb reflects approximately 34%, which is equivalent to 1/2, of the approximately 67% incident light _L2 that is the reflected light in the first region 2ba, onto the smooth surface 2c, and the remaining approximately 33% is reflected from the exit portion 21. ejects to the outside. The third region 2bc emits approximately 33% of the incident light _L2 , which is the reflected light from the second region 2bb, from the emitting portion 21 to the outside. As a result, the optical member 2 averages out the light amount of the emitted light _L3 in each region from the first region 2ba to the third region 2bc to be approximately the same, and reduces unevenness in brightness depending on the user's viewpoint position. It becomes a structure.

Moreover, in this case, the optical member 2 is located in the emission part 21 located on the entrance surface 2a side of the first region 2ba and the third region 2bc located closest to the terminal surface 2d side, as shown in FIG. 18, for example. Except for the injection part 21, the other injection parts 21 may have a substantially trapezoidal shape in cross-sectional view. In this case, in addition to the effect of reducing brightness unevenness described above, noise caused by unintended reflection of incident light _L2 on the second surface 21b of the emission part 21 is reduced in the first area ca and the second area 2bb. The optical member 2 can also provide a suppressing effect.

(3) For example, as shown in FIG. 19, the optical member 2 has a prism arrangement direction in which the plurality of prism parts 23 constituting the entrance part 2h are arranged, and the prism arrangement direction connects the exit surface 2b and the smooth surface 2c. It may be configured in a direction. Even in this case, the optical member 2 does not cause any relative positional deviation between the two reflecting surfaces, that is, the flat portion 22 and the smooth surface 2c, and does not require precision when attached to the holding member 3. It becomes a structure.

(4) Unless it is clearly incompatible, the optical member 2 may replace some or all of the components in the other embodiments (1) to (3) described above to the first to fourth embodiments or their variations. The configuration adopted in the example or any combination of configurations may be used. For example, in the blind spot auxiliary device 1 of the first to fourth embodiments, the optical member 2 may have a part of the emitting portion 21 formed into a substantially trapezoidal shape, or may divide the emitting surface 2b into a plurality of regions. The interval between them may be changed for each divided area. Furthermore, for example, in the first to third embodiments and their modifications, the optical member 2 may have a structure in which the light shielding film 5 is formed on part or all of the upper surface 2e and the lower surface 2f. Furthermore, for example, in the second embodiment, the optical member 2 may have a configuration in which the exit surface 2b does not have the exit region 2b1. In this way, the blind spot assisting device 1 can be configured by freely combining the constituent elements of each of the embodiments and modifications described above to the extent possible.

(5) In each of the above embodiments, elements constituting the embodiments are not necessarily essential, except in cases where it is specifically specified that they are essential or where they are clearly considered essential in principle. Needless to say. In addition, in each of the above embodiments, when numerical values such as the number, numerical value, amount, range, etc. of the constituent elements of the embodiment are mentioned, when it is clearly stated that it is essential, or when it is clearly limited to a specific number in principle. It is not limited to that specific number, except in cases where In addition, in each of the above embodiments, when referring to the shape, positional relationship, etc. of constituent elements, etc., the shape, It is not limited to positional relationships, etc.

(Features of the present invention)
[Claim 1]
A blind spot assist device,
It has an entrance surface (2a, 23a) on which outside scene light enters, a plurality of exit parts (21) and a plurality of flat parts (22), and an exit surface (2b) on which the incident light that enters from the entrance surface first reaches. ), and a smooth surface (2c) arranged opposite to the plurality of flat parts, and an optical member (2) made of a translucent material;
a holding member (3) that has a housing section (31) in which the optical member is housed, and that holds the optical member;
The surface of the accommodating portion facing the smooth surface of the optical member is defined as a bottom surface (31a), and at least the gap between the surface of the optical member including the smooth surface and the bottom surface of the accommodating portion is A light shielding member (4) disposed at the side end,
The plurality of flat parts are first reflective surfaces that reflect the incident light toward the smooth surface by total internal reflection,
The smooth surface is a second reflective surface that reflects the reflected light reflected by the flat portion onto the exit surface by total internal reflection,
A blind spot auxiliary device, wherein the plurality of emitting portions emit a part of the incident light or a part of the light reflected by the smooth surface to the outside on a side opposite to the holding member.
[Claim 2]
The blind spot auxiliary device according to claim 1, wherein the light shielding member is also arranged at an end of the gap opposite to the incident surface.
[Claim 3]
The blind spot assisting device according to claim 1 or 2, wherein the light shielding member is made of an elastic body.
[Claim 4]
The blind spot assisting device according to any one of claims 1 to 3, wherein the light shielding member is made of a light absorber.
[Claim 5]
The blind spot auxiliary device according to any one of claims 1 to 4, wherein the light shielding member is a member integrated with the optical member or the holding member.
[Claim 6]
The optical member is a surface connecting the smooth surface and the exit surface, and the two opposing surfaces are an upper surface (2e) and a lower surface (2f). The blind spot auxiliary device according to any one of claims 1 to 5, wherein at least a portion thereof is covered with a light shielding film (5).

2... Optical member, 21... Output section 21... Flat part, 2a, 23a... Incident surface,
2b...Injection surface 2b...Smooth surface, 2e...Upper surface 2e...Lower surface,
3... Holding member, 31... Accommodating part, 31a... Bottom surface, 4... Light shielding member,
5... Light shielding film

Claims (6)

A blind spot assisting device,
It has an entrance surface (2a, 23a) on which outside scene light enters, a plurality of exit parts (21) and a plurality of flat parts (22), and an exit surface (2b) on which the incident light that enters from the entrance surface first reaches. ), and a smooth surface (2c) arranged opposite to the plurality of flat parts, and an optical member (2) made of a translucent material;
a holding member (3) that has a housing section (31) in which the optical member is housed, and that holds the optical member;
The surface of the accommodating section facing the smooth surface of the optical member is defined as a bottom surface (31a), and at least the end of the gap between the smooth surface of the optical member and the bottom surface of the accommodating section on the side of the incident surface A light shielding member (4) disposed in the section,
The plurality of flat parts are first reflective surfaces that reflect the incident light toward the smooth surface by total internal reflection,
The smooth surface is a second reflective surface that reflects the reflected light reflected by the flat portion onto the exit surface by total internal reflection,
A blind spot auxiliary device, wherein the plurality of emitting portions emit a part of the incident light or a part of the light reflected by the smooth surface to the outside on a side opposite to the holding member. The blind spot auxiliary device according to claim 1, wherein the light shielding member is also arranged at an end of the gap opposite to the incident surface. The blind spot assist device according to claim 2, wherein the light shielding member is made of an elastic body. The blind spot auxiliary device according to claim 3, wherein the light shielding member is made of a light absorber. The blind spot assisting device according to claim 4, wherein the light shielding member is a member integrated with the optical member or the holding member. The optical member is a surface that connects the smooth surface and the exit surface, and the two opposing surfaces are an upper surface (2e) and a lower surface (2f). The blind spot auxiliary device according to any one of claims 1 to 5, at least a portion of which is covered with a light shielding film (5).

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