Optical components

Abstract

To provide an optical member which can further reduce the reduction of the light amount of emission light from an emission surface or change of the color tone.SOLUTION: An optical member 1 includes: a reflection member 2 having a reflection surface 2a; and a light adjustment member 3 which can switch a transparent state and a reflection state to each other, the light adjustment member having a plurality of divided regions 31 to 3N and facing the reflection surface. In the light adjustment member 3, one region is sequentially switched to a transparent state and all the other regions become in a reflection state.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an optical member including a member that functions as a pair of mirrors and capable of guiding and emitting incident light.

Background Art

[0002] Conventionally, an optical member is known (for example, Patent Document 1) in which external scene light is reflected and emitted between a pair of mirrors formed by oppositely disposing a mirror mainly for reflecting light and a half mirror for reflecting and transmitting light. Hereinafter, a surface mainly for reflecting external scene light among the optical members is referred to as a "reflecting surface", and a surface for reflecting and emitting external scene light is referred to as an "emitting surface".

[0003] In the optical member described in Patent Document 1, part of the external scene light incident on the half mirror is reflected to the mirror side, and the other part of the external scene light is emitted to the outside through the half mirror. By repeating the reflection and emission of the external scene light in a wide range between the pair of mirrors, it is possible to visually recognize the external scene in a wide range.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the optical components described above, in addition to reflection and emission (transmission) of ambient light, absorption of ambient light also occurs in half-mirrors. As reflection is repeated, the amount of light emitted from the half-mirror decreases, and the ambient view becomes darker the further away from the incident side of the emission surface is. Metal vapor-deposited films and dielectric multilayer films can be used as half-mirrors, but in the former case, the light absorption rate in the half-mirror is 30% or more, resulting in a very large amount of light loss. On the other hand, in the latter case, the light absorption rate in the half-mirror is smaller than in the former case, and light loss can be suppressed, but the reflectivity changes depending on the wavelength of light and the angle of incidence. Therefore, in this case, the brightness and color tone of the ambient view on the emission surface of the optical component may change depending on the angle of incidence of ambient light to the optical component.

[0006] In view of the above, the present invention aims to provide an optical component that can reduce the decrease in light intensity and the change in color tone of the emitted light at the emission surface compared to conventional methods. [Means for solving the problem]

[0007] To achieve the above objective, the optical member described in claim 1 comprises a reflective member (2, 6) having reflective surfaces (2a, 6a) that reflect light, and a dimming member (3) that is switchable between a transparent state and a reflective state, has a plurality of partitioned regions (31~3N), and is positioned opposite the reflective surface, wherein the dimming member sequentially switches one of the plurality of regions to a transparent state, and the remaining regions, which are different from the one region that has been made transparent, to a reflective state. The total time during which all of the multiple regions become transparent once is defined as the full-surface transition time (S), and the full-surface transition time is 1 / 30th of a second or less. .

[0008] This optical component allows for the guidance of ambient light between two components: a reflective component and a dimming component having multiple regions that can be switched between transparent and reflective states, as well as the emission of ambient light from the dimming component. The dimming component has one region that is transparent and the remaining regions that are reflective, and the regions that are transparent are sequentially switched. In the dimming component, the reflectivity of visible light in the reflective state is not affected by wavelength or angle of incidence, and in the transparent state, the transmittance of visible light is high, reducing losses due to absorption. Therefore, this optical component can reduce the decrease in light intensity and change in color tone of the emitted light at the emission surface compared to conventional designs.

[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 an optical component of the first embodiment. [Figure 2] This figure shows an example of the partitioned areas of the dimming component and the connection to the circuit board. [Figure 3] This is an explanatory diagram showing the case where the first region of the dimming component is transparent. [Figure 4] This is an explanatory diagram illustrating the case where the second region of the dimming component is transparent. [Figure 5] This is an explanatory diagram illustrating the case where the Nth region of the dimming component is transparent. [Figure 6] This is an explanatory diagram regarding the width of the partitioned area of ​​the dimming component. [Figure 7] This is a cross-sectional view showing an optical component of the second embodiment. [Figure 8] This is an explanatory diagram showing the case where the first region of the dimming component is transparent. [Figure 9] This is an explanatory diagram illustrating the case where the K region of the dimming component is transparent. [Figure 10]This is an explanatory diagram illustrating the case where the Nth region of the dimming component is transparent. [Figure 11] This figure shows the optical member and internal light guide of the third embodiment. [Figure 12] This is an explanatory diagram of the protruding portion of the light guide according to the third embodiment. [Figure 13] This is an explanatory diagram illustrating the gaps in light rays caused by the shape of the light guide in the comparative example. [Figure 14] This is an explanatory diagram illustrating the suppression of gaps in light rays due to the shape of the light guide according to the third embodiment. [Figure 15] This is an enlarged cross-sectional view showing other examples of the shape of the protruding part of the light guide. [Figure 16] This is an explanatory diagram of the emission of incident light in the optical element of the third embodiment. [Modes for carrying out the invention]

[0011] The embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be denoted by the same reference numerals.

[0012] (First Embodiment) The optical element 1 of the first embodiment will be described with reference to the drawings. The optical element 1 of this embodiment can be used as a blind spot assisting device, which is attached to, for example, a member or obstacle that obstructs the user's field of view and creates a blind spot, and allows the user to see the scenery in the blind spot area. For example, in the case of an in-vehicle application, the optical element 1 is attached to the pillar of the vehicle on which it is mounted, and guides ambient light from the area that becomes a blind spot due to the pillar towards the user, allowing the user to see the scenery in the blind spot area.

[0013] Figure 1 corresponds to the cross-sectional view of line II in Figure 2. In Figures 3 to 6, to make it easier to understand whether the multiple regions 31 to 3N of the dimming member 3, which will be described later, are in a transparent state or a reflective state, the reflective regions are hatched and the transparent regions are shown in white. Also, the cross-sectional views from Figure 3 onwards correspond to Figure 1.

[0014] The optical component 1 comprises, for example, a reflective member 2 having a reflective surface 2a that reflects light, and a dimming member 3 positioned opposite to the reflective surface 2a, substantially parallel to the reflective surface 2a, and capable of switching between a transparent state that transmits light and a reflective state that reflects light. The optical component 1 has the reflective member 2 and the dimming member 3 mounted on a housing or holding member (not shown), and these components are held in a substantially parallel state. When ambient light enters the dimming member 3 from behind the reflective member 2, a portion of the ambient light is repeatedly reflected by the reflective portion of the dimming member 3 and the reflective surface 2a of the reflective member 2, while a portion of the ambient light is emitted from the transparent portion of the dimming member 3. As a result, the optical component 1 guides ambient light entering from a blind spot region blocked by an obstacle (not shown) located behind the reflective member 2 between the reflective member 2 and the dimming member 3, and emits this ambient light to the outside over a wide area of ​​the dimming member 3, thereby allowing the user to see the ambient view in the blind spot region.

[0015] In this specification, "approximately parallel" includes not only a state of being perfectly parallel, but also a state in which the lights are slightly tilted to the extent that it does not interfere with the guidance of ambient light due to dimensional errors or mounting accuracy of the housing or retaining members (not shown).

[0016] In this embodiment, the reflective member 2 is a member having a reflective surface 2a with a visible light reflectivity of a predetermined value or higher (for example, 80% or more, though not limited to this value). The reflective member 2 is formed by laminating a thin metal film made of a metallic material such as Al (aluminum) and a transparent protective film made of silicon in that order on a substrate made of any material such as glass, ceramic, or resin. The reflective member 2 is held in a housing or the like (not shown) with its reflective surface 2a facing the dimming member 3, and acts as a mirror that reflects the light reflected by the dimming member 3 back towards the dimming member 3.

[0017] The dimming member 3, as shown in Figure 2 for example, has multiple partitioned regions 31 to 3N (N: a natural number of 2 or more), and is a member that can switch between a transparent state that transmits visible light and a reflective state that reflects visible light for each of the multiple regions 31 to 3N. The dimming member 3 may also be called a "dimming mirror". For example, electrochromic or gaschromic materials can be used as the dimming member 3. In the case of an electrochromic dimming member 3, 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 "dimming mirror layer". The electrolyte layer may also be called an ion storage layer. In the dimming member 3, 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 the 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 technology, the dimming element 3 can switch between a transparent state and a reflective state depending on whether or not voltage is applied.

[0018] For the sake of explanation, the surface of the dimming member 3 that faces the reflective surface 2a of the reflective member 2 will be referred to as the "opposing surface 3a," and the surface opposite to the opposing surface 3a will be referred to as the "emitting surface 3b." Furthermore, the planar direction along the opposing surface 3a, which is the direction in which ambient light is guided by reflection from the opposing surface 3a and the reflective surface 2a, will be referred to as the "light guidance direction." In addition, of the two ends of the dimming member 3 in the light guidance direction, the end on the side where light is first incident will be referred to as the "incident end," the end on the opposite side of the incident end will be referred to as the "end end," and the incident end side of the outer edge of the dimming member 3 will be referred to as the "incident end side 3A."

[0019] Furthermore, as shown in Figure 2, if the number of regions is N (N: a natural number greater than or equal to 2), the regions are referred to sequentially from the incident end to the terminal end as the first region 31, the second region 32, the third region 33, the fourth region 34, ..., the (N-1)th region 3(N-1), and the Nth region 3N. Note that the dashed lines in Figure 2 are for convenience only, indicating the boundaries of each region 31 to 3N of the dimming member 3, and are not actually visible to the user.

[0020] The dimming member 3 is partitioned such that multiple regions 31 to 3N are arranged parallel to the incident edge 3A, as shown in Figure 2, for example. In the example in Figure 2, the outer shape of the dimming member 3 is rectangular and the outer shapes of the multiple regions 31 to 3N are rectangular in plan view, but it is not limited to this. For example, if the outer shape of the dimming member 3 is a parallelogram in plan view, the multiple regions 31 to 3N are partitioned parallel to the incident edge 3A, and their outer shapes are elongated parallelograms. Thus, the outer shapes of the dimming member 3 and the multiple regions 31 to 3N may be changed as appropriate.

[0021] The dimming member 3 has wiring 4, such as an FPC, connected to transparent electrodes (not shown) in each of the multiple regions 31 to 3N, and is also connected to a circuit board 5 for drive control via the wiring 4. This allows the dimming member 3 to control the switching between transparent and reflective states in each of the multiple regions 31 to 3N. The circuit board 5 is an electronic unit consisting of a board with circuit wiring (not shown) and a CPU, ROM, RAM, I / O, etc. (not shown) mounted on it. The circuit board 5 is connected to an arbitrary power supply (not shown) and is positioned behind the reflective member 2 (on the opposite side of the reflective surface 2a).

[0022] The dimming element 3, for example, has a visible light reflectance of 70% or more and a transmittance of almost 0% in the reflective state. Also, the dimming element 3, for example, has a visible light transmittance of 70% or more in the transparent state, and a reflectance of 4-5% on one of the opposing surfaces 3a and the ejection surface 3b, and 8-10% on both sides. As a result, the dimming element 3 has a higher visible light transmittance in the transparent state compared to conventional half-mirrors made of metal vapor-deposited films, and can secure a sufficient amount of transmitted light. Furthermore, unlike conventional half-mirrors made of dielectric multilayer films, the dimming element 3's reflectance in the reflective state does not depend on the incident angle or wavelength of the ambient light L1 to the opposing surface 3a, so there is no change in the brightness or color tone of the ambient view seen by the user on the ejection surface 3b.

[0023] When no voltage is applied, for example, all regions 31 to 3N of the dimming member 3 are in a reflective state, mainly reflecting visible light. During dimming control, a voltage is applied to one of the multiple regions of the dimming member 3, and the region to which the voltage is applied becomes transparent, mainly transmitting visible light. Then, one of the regions from the first region 31 to the Nth region 3N becomes transparent, and the remaining regions become reflective, and dimming control is performed in which the region that becomes transparent is sequentially switched.

[0024] For example, as shown in Figure 3, at a certain timing, the dimming member 3 becomes transparent in the first region 31 due to the application of voltage, while the remaining region becomes reflective. At this time, ambient light L1 incident on the first region 31 is transmitted and emitted from the first region 31. On the other hand, ambient light L1 incident on the other regions is reflected towards the reflective member 2, and then reflected repeatedly by the reflective surface 2a and the dimming member 3, and guided in a different direction from the ambient light L1 that reached the first region 31.

[0025] Furthermore, as shown in Figure 4, for example, at other times, the dimming member 3 switches the second region 32 from a reflective state to a transparent state by applying a voltage, leaving the remaining region in a reflective state. In other words, when the dimming member 3 switches the first region 31 from a transparent state to a reflective state, the second region 32 is switched from a reflective state to a transparent state, while the other regions 33 to 3N remain in a reflective state. At this time, ambient light L1 that reaches the transparent second region 32 is emitted from the second region 32, while light that reaches the other regions in a reflective state is guided away from the dimming member 3 without being emitted.

[0026] Then, the dimming member 3 sequentially switches one region to a transparent state, and as shown in Figure 5, for example, at other times, the Nth region 3N becomes transparent due to the application of voltage, and the remaining region becomes reflective. At this time, the ambient light L1 is guided by the dimming member 3 and the reflective surface 2a, and the light that reaches the transparent Nth region 3N is emitted as is, while the light that does not reach the Nth region 3N is guided in other directions.

[0027] In this way, the dimming member 3 has multiple regions in which one region is transparent and other regions are reflective, and the region that is transparent is sequentially changed to control the dimming. As a result, ambient light L1 incident between the reflective member 2 and the dimming member 3 is reflected with high reflectivity in the reflective region of the dimming member 3, while being emitted with high transmittance from the transparent region. Furthermore, because the transparent region of the dimming member 3 is sequentially switched, ambient light L1 is emitted over a wide area, allowing the user to see the ambient scenery in blind spots.

[0028] The dimming member 3 preferably satisfies the following equation (1), for example, as shown in Figure 6, with D being the width in the light-guiding direction of the K region 3K (1≦K≦N) and T being the gap between the reflective surface 2a and the dimming member 3.

[0029] 2T·tanθ1≧D···(1) In equation (1), θ1 is the light L incident on the dimming member 3 from the emission surface 3b side. 11 This is the angle of incidence of the light L with respect to the emission surface 3b. In other words, θ1 is the angle of incidence of the light L 11 This is the angle between the direction of propagation and the direction normal to the emission surface 3b. The width D in the light guide direction of each region 31 to 3N is, for example, assumed to be approximately uniform. Approximately uniform means that the width D of each region is the same, as well as slightly different due to unavoidable dimensional errors, etc.

[0030] If equation (1) is satisfied, then, as shown in Figure 6, the light L 11 In this case, all of the light that passes through the transparent K region 3K and is reflected by the reflective surface 2a reaches regions other than the K region 3K and is not emitted along with a portion of the ambient light L1. Conversely, if equation (1) is satisfied Na In this case, light L passes through the transparent K region 3K and is reflected by the reflective surface 2a. 11 A portion of it reaches region K 3K again and is emitted together with a portion of the ambient light L1. In other words, the dimming member 3 satisfies equation (1) when the width of each region 31 to 3N satisfies the ambient light L1 emitted from each transparent region, and the light L from the emission surface 3b side 11 The superposition ceases, and the light L 11 Noise caused by this is suppressed.

[0031] Furthermore, in the case of 2T·tanθ1=D, the transparent region and the light L that enters from the transparent region 11 In this case, the gap between the region where the light reflected from the reflective surface 2a reaches the opposing surface 3a is zero, and there is no overlap. Furthermore, in this case, a portion of the opposing surface 3a that the reflected light of the ambient light L1 from the reflective surface 2a reaches next is designated as the illumination region, and the gap between the illumination region and the region where the light reflected from the illumination region in the reflective state is reflected again by the reflective surface 2a and reaches the opposing surface 3a is zero, and there is no overlap. Therefore, the number of region divisions N in the dimming member 3 is minimized, and the number of reflections in the light guide of ambient light until it reaches the Nth region 3N is also minimized, thus minimizing the loss of light rays in the light guide.

[0032] Here, the time resolution of human vision is defined as C (unit: Hz), and the time required for switching control to make each region from the first region 31 to the Nth region 3N transparent once is defined as the "overall switching time". In this case, it is preferable that the dimming member 3 satisfies the following equation (2) in dimming control, with the overall switching time being S (unit: sec).

[0033] S < 1 / C ... (2) The overall switching time S refers to the total transparent time for all regions, with each region 31 to 3N being transparent after a single voltage application, defined as the "transparent time". In other words, it is preferable that the dimming control is performed with an overall switching time less than the time resolution of human vision (e.g., 1 / 30th of a second or less). For example, the dimming member 3 preferably has an overall switching time S of 1 / 30th of a second or less, and more preferably 1 / 60th of a second or less. This allows the dimming member 3 to operate in a way that prevents the user from noticing the overall switching between transparent and reflective states in multiple regions 31 to 3N, i.e., to avoid causing discomfort due to the dimming control. Furthermore, the dimming member 3 allows the user to see the transmitted light from each of the multiple regions 31 to 3N, i.e., the transmitted light from the entire emission surface 3b, through the above dimming control.

[0034] The dimming member 3 can individually control the transparency time of each area by changing the voltage application time in each of the plurality of areas 31 to 3N. For example, the transparency times of the first area 31, the second area 32, ··· the Kth area 3K, ··· the (N-1)th area 3(N-1), and the Nth area 3N are t1, t2, ··· t K ··· t (N-1) 、t N If we set them like this, the full-screen switching time S is expressed by the following formula 3. Note that the transparency times t1 to t N are approximately the same as the energization time in each area.

[0035]

Equation

[0036] I1 = T m × t1 / S ··· (4) I2 = R m × R f × T m · t2 / S ··· (5) I N = R m (N-1) × R f (N-1) × T m × t N / S ··· (6) That is, the lengths of the transparency times t1 to t N are proportional to the brightness of the outdoor scene that the user visually recognizes in each of the first area 31 to the Nth area 3N. In other words, by appropriately changing the transparency times t1 to t N , the light amounts I1 to I of the first area 31 to the Nth area 3N NIt is possible to make them equal. For example, to make the light intensity of the first region 31 and the second region 32 equal, it is sufficient to satisfy equations (7) and (8) below.

[0037] I2 = I1 × R m ×R f ×t2 / t1···(7) t2 = t1 / (R m ×R f )···(8) Since the same relationship holds for regions 33 and beyond in the third region, if the light intensity I3 in the third region 33 is to be equal to the light intensity in the first region 31 and the second region 32, then it is sufficient to satisfy equations (9) and (10) below.

[0038] I3 = I2 × R m ×R f ×t3 / t2=I1×R m 2 ×R f 2 ×t3 / t1···(9) t3 = t1 / (R m 2 ×R f 2 )···(10) Similarly, the light intensity I of region N3N N To make this equal to the light intensity in each of the first region 31 to the (N-1)th region 3(N-1), it is sufficient to satisfy equations (11) and (12) below.

[0039] I N =I (N-1) ×R m ×R f ×t N / t (N-1) =I1×R m (N-1) ×R f (N-1) ×t N / t1···(11) t N = t1 / (R m (N-1) ×R f (N-1) )···(12) The dimming component 3, by performing dimming control that satisfies equation (12), makes it possible to equalize the amount of emitted light in each region from region 31 to 3N, thereby equalizing the brightness of the exterior view seen by the user.

[0040] The optical member 1 of this embodiment comprises a dimming member 3 having multiple regions 31 to 3N that can be switched between a transparent state and a reflective state, and a reflective member 2. It can reflect and guide ambient light L1 between the reflective surface 2a of the reflective member 2 and the opposing surface 3a of the dimming member 3. Furthermore, the optical member 1 can emit ambient light from the entire area of ​​the dimming member 3 by sequentially shifting the region that becomes transparent while keeping one of the regions 31 to 3N transparent and the remaining regions reflective. By using such a dimming member 3, the optical member 1 can achieve a high visible light reflectivity when reflecting ambient light at the opposing surface 3a, while also achieving a high visible light transmittance when emitting ambient light from the emission surface 3b, thereby ensuring sufficient light intensity of the emitted light. In addition, since the reflectivity of the dimming member 3 in the reflective state does not depend on the incident angle or wavelength of ambient light, the optical member 1 can suppress changes in brightness and color tone at the emission surface 3b.

[0041] (Second Embodiment) The optical component 1 of the second embodiment will be described with reference to the drawings.

[0042] The optical member 1 of this embodiment differs from the first embodiment in that, in addition to the reflective member 2 and the dimming member 3, it also includes a transparent light guide 6 to which these members are attached, as shown in Figure 7, for example. This embodiment will mainly describe this difference.

[0043] The light guide 6 is made of any translucent material such as polyethylene terephthalate, polycarbonate, polyethylene, acrylic, or glass. In this embodiment, the light guide 6 is separate from the reflective member 2 and the dimming member 3, and the reflective member 2 and the dimming member 3 are attached to it with an optical adhesive such as OCA (not shown). The light guide 6 has a smooth first surface 6a and a second surface 6b that is substantially parallel to the first surface 6a, as shown in Figure 7, for example. In the light guide 6, for example, the reflective surface 2a of the reflective member 2 is attached to a part of the first surface 6a, and the dimming member 3 is attached to the entire area of ​​the second surface 6b. In the light guide 6, the area of ​​the first surface 6a that is exposed from the reflective member 2 is the incident portion 6aa that allows ambient light L1 to enter the interior.

[0044] For the sake of explanation, the light that enters the light guide 6 from the incident portion 6aa of the ambient light L1 will be referred to as "incident light L2," and the light that is emitted to the outside from the second surface 6b side through the transparent dimming member 3 will be referred to as "exited light L3." In addition, the first surface 6a of the light guide 6 may be referred to as the "smooth surface," and the second surface 6b may be referred to as the "attachment surface."

[0045] In the optical member 1 of this embodiment, for example as shown in Figure 8, when ambient light L1 is incident on the incident portion 6aa at an incident angle θ2, it is refracted within the light guide 6 with refractive index n (n>1), and the incident light L2 reaches the second surface 6b at an incident angle φ. Of the incident light L2, the portion that reaches the transparent region of the dimming member 3 held on the second surface 6b (attachment surface) (the first region 31 in the example of Figure 8) is emitted from the emission surface 3b as emitted light L3. On the other hand, the incident light L2 that reaches the reflective region of the dimming member 3 is repeatedly reflected between the opposing surface 3a of the dimming member 3 and the reflective surface 2a of the reflective member 2, as shown in Figures 9 and 10, and is guided inside the light guide 6. Subsequently, when the guided incident light L2 reaches the transparent region of the dimming member 3, it is emitted from the emission surface 3b as emitted light L3. The dimming member 3, as in the first embodiment described above, is dimmed, so that it emits light L3 from the entire surface of the emission surface 3b, allowing the user to see the outside scenery in the blind spot area. When the reflective member 2 and the dimming member 3 are parallel, the emitted light L3 is emitted outward at the same angle θ2 as the ambient light L1.

[0046] The dimming member 3 preferably satisfies the following equation (13), for example, as shown in Figure 8, where D is the width in the light-guiding direction of each region 31 to 3N, and T is the gap between the reflective surface 2a and the dimming member 3, i.e., the thickness of the light guide 6. In Figure 8, for clarity, the width D of the first region 31 is shown as a representative example among the widths D in the light-guiding direction of each region 31 to 3N.

[0047] 2T·tanφ = 2T·tan(sin -1 (sinθ² / n))≧D···(13) The dimming member 3, as in the first embodiment where equation (1) is satisfied, has widths of each region 31 to 3N that satisfy equation (13), thereby allowing ambient light L1 emitted from each transparent region to receive light L from the emission surface 3b side. 11 The superposition ceases, and the light L 11 Noise caused by this is suppressed. Also, when 2T·tanφ=D, the gap between the illumination region where the incident light L2 illuminates the dimming member 3 in one go and the region where the incident light L2 reflected from the illumination region in a reflective state illuminates the dimming member 3 again via the reflective surface 2a, i.e., the gap in the light guide, becomes zero. In this case, the number of region divisions N in the dimming member 3 is minimized, and consequently the number of reflections in the light guide of the incident light L2 until it reaches the Nth region 3N is also minimized, so the loss of light rays in the light guide can be minimized.

[0048] In this embodiment, the reflective member 2 only needs to function as a mirror, and may be a thin film formed by depositing a metal material or the like onto a part of the first surface 6a of the light guide 6, and may have no substrate. In this case, it is not necessary to place an optical adhesive between the reflective member 2 and the light guide 6.

[0049] This embodiment also provides an optical member 1 that offers the same effects as the first embodiment described above. Furthermore, in this embodiment, even when external forces such as vibrations are applied in automotive applications, the relative position of the reflective member 2 and the dimming member 3 does not shift, and it is possible to easily attach it to obstacles such as pillars and pillar covers, and the structure does not require excessive precision in installation.

[0050] (Third embodiment) The optical component 1 of the third embodiment will be described with reference to the drawings.

[0051] The optical member 1 of this embodiment, as shown in Figure 11 for example, has a light guide 6 as a reflective member 2, and the first surface 6a of the light guide 6 functions as a reflective surface that reflects ambient light L1 to the dimming member 3. In addition, a prism array 7 is bonded to the surface of the dimming member 3 opposite to the light guide 6. The optical member 1 of this embodiment differs from the second embodiment in these respects. This embodiment will mainly describe these differences.

[0052] In this embodiment, the light guide 6 is configured such that its smooth first surface 6a functions as a reflective surface that reflects incident light L2 using total internal reflection. Specifically, the light guide 6 is designed such that the refractive index n of its constituent material is greater than n0, where n0 is the refractive index of the external medium of the light guide 6, and the angle of incidence of the incident light L2 with respect to the second surface 6b and the first surface 6a is φ, satisfying equation (14) below.

[0053] sinφ≧n0 / n···(14) The light guide 6 satisfies equation (14), so that the inner surface of the first surface 6a becomes an interface with an external medium having a lower refractive index than the light guide 6, allowing the incident light L2 reflected by the dimming member 3 to be totally reflected by the first surface 6a and guided towards the dimming member 3. In other words, in this embodiment, the light guide 6 is a transparent member that serves as both a support for the dimming member 3 and a reflective member paired with the dimming member 3. As shown in Figure 11, for example, the light guide 6 repeatedly reflects the incident light L2 between the reflective portion of the opposing surface 3a of the dimming member 3 and the first surface 6a, and the light that reaches the end surface 6e is emitted to the outside as afterglow L4. The end surface 6e is the surface that connects the end of the first surface 6a opposite to the inclined surface 6d and the end of the second surface 6b opposite to the incident surface 6c.

[0054] Furthermore, if the external medium is an air layer, n0=1. The incident angle φ is the angle between the direction of propagation of the incident light L2 and the direction normal to the first surface 6a or the second surface 6b. The incident angle φ is the same regardless of the number of reflections at the opposing surface 3a and the first surface 6a when the first surface 6a and the opposing surface 3a of the dimming member 3 are parallel. For the sake of explanation, the direction normal to the second surface 6b will be referred to as the "direction normal to the second surface" below.

[0055] The light guide 6 has a protruding portion 61 that extends beyond the first surface 6a in the thickness direction, as shown in Figure 12, with the thickness direction being the direction that connects the first surface 6a and the second surface 6b along the direction normal to the second surface. The protruding portion 61 has, for example, the maximum height T in the thickness direction of the light guide 6. d However, it has a single prism shape that is larger than the height T from the second surface 6b to the first surface 6a. The projection 61 is adjacent to the second surface 6b, and the surface that extends in a direction intersecting the second surface 6b is the incident surface 6c that causes ambient light L1 to enter the interior of the light guide 6. As a result, compared to the second embodiment, the light guide 6 has a wider area in which the incident light L2 from the incident surface 6c first reaches the second surface 6b and the opposing surface 3a of the dimming member 3, making it possible to guide more light and resulting in a configuration that does not create gaps in the light guide.

[0056] The projection 61 is inclined such that the incident surface 6c is tilted at an angle ψ with respect to the direction normal to the second surface, and the angle it makes with the second surface 6b is acute. The inclination angle ψ of the incident surface 6c with respect to the direction normal to the second surface is smaller than the incident angle φ of the incident light L2. In this case, if ψ < π / 2 - φ according to the refraction condition, the incident light L2 is refracted in a direction in which φ is greater than the incident angle θ2 of the background light L1, and is guided to a wider area of ​​the second surface 6b.

[0057] The protruding portion 61 is, for example, an inclined surface 6d that connects the incident surface 6c and the first surface 6a, and the inclined surface 6d is covered with a light-absorbing film 62. This suppresses the intrusion of unintended ambient light from the inclined surface 6d and the reflection of incident light L2 from the incident surface 6c by the inclined surface 6d, thereby preventing the generation of ghost images caused by unintended light superimposed on the emitted light L3. The light-absorbing film 62 is composed of any light-shielding material that mainly absorbs visible light, such as black paint, and is formed by spray coating or the like. The light-absorbing film 62 only needs to be configured to absorb visible light without transmitting it, and its thickness is arbitrary.

[0058] As shown in Figure 12, for example, the inclined surface 6d of the protruding portion 61 is inclined at an angle ξ with respect to the first surface 6a. If the angle ξ is greater than the incident angle φ of the incident light L2, a "gap in the light rays," which will be described later, may occur. Therefore, the inclined surface 6d is configured to satisfy ξ < φ in order to prevent this.

[0059] For the sake of explanation, the end of the inclined surface 6d on the incident surface 6c side will be referred to as the "first end 6da," and the incident light L2 that enters the incident surface 6c from near the first end 6da will be referred to as the "incident light L 2a The end of the inclined surface 6d on the first surface 6a side is called the "second end 6db," and the incident light L2 reflected near the second end 6db on the first surface 6a is called the "incident light L 2b It is called "".

[0060] For example, as shown in the comparative example in Figure 13, when the inclination angle ξ of the inclined surface 6d > incident angle φ, the incident light L 2a The incident light L passes at a position away from the second end 6 dB, and is reflected near the second end 6 dB. 2b A gap is created between this and the light L. 2a and incident light L 2b The gap between these surfaces is called a "light ray gap." When this light ray gap occurs, a region may be created where the incident light L2 does not reach the second surface 6b and, consequently, the opposing surface 3a of the dimming member 3. In this case, a light guide gap occurs in the emitted light L3, making it impossible to ensure the continuity of the display.

[0061] Therefore, the inclined surface 6d is configured such that the inclination angle ξ < incident angle φ. In this case, for example, as shown in Figure 14, the incident light L 2a The incident light L will pass near the second end at 6 dB. 2b This results in a state where no gaps in the light rays occur between the light guide and the optical member 1. As a result, no gaps in the light rays, and therefore no gaps in the light guide, are created in the light guide 6, and the optical member 1 can ensure the continuity of the display on the emission surface 3b of the dimming member 3.

[0062] Furthermore, if the inclined surface 6d has a spread such that the incident angle θ2 of the ambient light L1 is θ2±Δθ2 and the incident angle φ of the incident light L2 is φ±Δφ, then by satisfying the inclination angle ξ<φ-Δφ, it is possible to suppress the generation of gaps in the light rays within the range of θ2±Δθ2.

[0063] In the above explanation, the inclined surface 6d was assumed to be a single flat inclined surface, and its inclination angle ξ was described as a representative example where it is smaller than the incident angle φ. However, the inclined surface 6d is not limited to being a single inclined surface. For example, the inclined surface 6d may have multiple surfaces or may be a curved surface. Specifically, the inclined surface 6d may be a rectangular shape with two surfaces, as shown in Figure 15. In this way, when the inclined surface 6d is configured other than a single inclined surface, it is sufficient that the incident light L2 incident from the vicinity of the first end 6da passes through the vicinity of the second end 6db, and its external shape is not particularly limited. In this case, the inclination angle ξ can also be said to be the angle between the virtual straight line VL1 connecting the first end 6da and the second end 6db, and the normal direction to the first surface 6a, as shown in Figure 15. Therefore, the shape of the inclined surface 6d does not matter as long as it satisfies ξ < φ, but regardless of the shape, the region from the first end 6da to the second end 6db is covered by the light-absorbing film 62.

[0064] The prism array 7, like the light guide 6, is a light-transmitting member made of any transparent material such as acrylic, and is attached to the dimming member 3 with an optical adhesive such as OCA (not shown). The prism array 7 is, for example, a sheet in which a plurality of prism sections 71, each shaped like a rectangular prism, are formed.

[0065] The multiple prism sections 71, as shown in Figure 16, for example, have parallel surfaces 71a that are substantially parallel to the incident surface 6c and intersecting surfaces 71b that are adjacent to the parallel surfaces 71a and intersect with the parallel surfaces 71a, and have similar shapes to each other. The parallel surfaces 71a of the multiple prism sections 71 function as ejection surfaces that emit incident light L2 that has passed through the transparent region of the dimming member 3 to the outside. For example, a light-absorbing film (not shown) is formed on the surface of the intersecting surfaces 71b of the multiple prism sections 71, so that unintended ambient light from the prism array 7 side does not enter the dimming member 3. This makes it possible to suppress noise caused by unintended ambient light from the prism array 7 side superimposing on the ejected light L3. The prism array 7 is formed by a known plastic molding method using a mold, for example, to form a surface having multiple prism sections 71.

[0066] This embodiment also provides an optical component 1 that has the same effects as the second embodiment described above. Furthermore, in this optical component 1, since the first surface 6a of the light guide 6, which is made of a transparent material, functions as a reflective surface, light absorption at the reflective surface does not occur as would occur if the reflective surface were made of a reflective material, reducing reflection loss at the first surface 6a and improving the efficiency of light guidance. In addition, a separate reflective component is not required, making it possible to make the entire optical component 1 thinner. Moreover, in this optical component 1, by attaching the prism array 7 to the dimming member 3, the effect of suppressing noise caused by unintended ambient light from the prism array 7 side is also obtained.

[0067] (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.

[0068] 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.

[0069] (Features of the present invention) [Claim 1] An optical component, A reflective member (2, 6) having reflective surfaces (2a, 6a) that reflect light, It is possible to switch between a transparent state and a reflective state, and comprises a dimming member (3) having a plurality of partitioned regions (31 to 3N) and positioned opposite the reflective surface, The dimming member is an optical member in which one of the multiple regions is sequentially switched to a transparent state, and the remaining regions, which are different from the one region that is made transparent, become reflective. [Claim 2] It is separate from the reflective member and further comprises a light guide (6) made of a transparent material, The optical member according to claim 1, wherein the reflective member and the light-adjusting member are attached to the light guide. [Claim 3] The reflective member is a light guide (6) made of a transparent material with a refractive index n (n>1), The dimming member is attached to the light guide, The reflective surface is a smooth surface (6a) of the light guide that faces the adhesive surface (6b) to which the dimming member is attached, and reflects the light reflected in the reflective region of the incident light (L2) incident on the light guide toward the dimming member by total internal reflection. Let T be the distance between the adhesive surface and the smooth surface of the light guide in the thickness direction. The light guide has a maximum height of T in the thickness direction. d (>T), and having a protrusion (61) that protrudes from the smooth surface, The optical member according to claim 1, wherein the protruding portion has an incident surface (6c) that extends in a direction intersecting the plane formed by the adhesive surface, causing ambient light (L1) to be incident on the side of the dimming member. [Claim 4] It further comprises a prism array (7) having multiple prism sections (71), The optical member according to claim 3, wherein the prism array is attached to the surface of the light-adjusting member opposite to the reflective member. [Claim 5] Let N be the number of the multiple regions (N: a natural number greater than or equal to 2), and let the region located at the end on the side where the ambient light is incident be the first region (31), and let the remaining regions from the first region toward the end opposite to the first region be the second to the Nth region (32 to 3N), and let t1 and t1 be the times when the first region and the Nth region are transparent, respectively. N Let the reflectance of the reflective surface be R f The reflectance of the reflective region of the dimming member is R m as, The dimming member is t N = t1 / (R m (N-1) ×R f (N-1) The optical member according to any one of claims 1 to 4, wherein dimming control is performed that satisfies the following conditions. [Claim 6] The optical member according to any one of claims 1 to 5, wherein the total time for all of the multiple regions to become transparent once each is defined as the overall switching time (S), and the overall switching time is 1 / 30 second or less. [Explanation of Symbols]

[0070] 2...Reflective member, 2a...Reflective surface, 3...Dimming member 31~3N...Multiple regions (divided by dimming components), 6...Light guide 6a...Smooth surface (first surface), 6b...Adhesion surface (second surface), 6c...Incident surface 7...Prism array, 71...Prism section, L1...Outdoor light, L2...Incident light S...Full transition time

Claims

1. An optical component, A reflective member (2, 6) having reflective surfaces (2a, 6a) that reflect light, It is possible to switch between a transparent state and a reflective state, and comprises a dimming member (3) having a plurality of partitioned regions (31 to 3N) and positioned opposite the reflective surface, The dimming member sequentially switches one of the multiple regions to a transparent state, while the remaining regions, which are different from the one region that has been made transparent, become reflective. An optical member wherein the total time for all of the multiple regions to become transparent once is defined as the overall switching time (S), and the overall switching time is 1 / 30 second or less.

2. It further comprises a light guide (6) made of a transparent material, which is separate from the reflective member. The optical member according to claim 1, wherein the reflective member and the light-adjusting member are attached to the light guide.

3. The optical member according to Claim 1, wherein the surface of the dimming member facing the reflective member is defined as the opposing surface (3a), the surface opposite to the opposing surface is defined as the emission surface (3b), the direction along the opposing surface in which light is guided by the reflective region and the reflective surface is defined as the light guidance direction, T is the gap between the opposing surface and the reflective member in the direction normal to the opposing surface, θ1 is the angle of incidence of light incident on the emission surface from the opposite side of the reflective member, and D is the width of each of the plurality of regions in the light guidance direction, such that 2T・tanθ1 ≥ D.

4. The reflective member is a light guide (6) made of a transparent material with a refractive index n (n > 1), The dimming member is attached to the light guide, The reflective surface is a smooth surface (6a) of the light guide that faces the adhesive surface (6b) to which the dimming member is attached, and the incident light (L) incident on the light guide ２ ) The light reflected in the reflective region is reflected back to the dimming member by total internal reflection. Let T be the distance between the adhesive surface and the smooth surface of the light guide in the thickness direction. The light guide has a maximum height of T in the thickness direction. ｄ (>T), and having a protrusion (61) that protrudes from the smooth surface, The protruding portion has a surface that extends in a direction intersecting the plane formed by the adhesive surface, and the surface is such that it does not emit external light (L １ The optical member according to claim 1, wherein the incident surface (6c) is an incident surface that causes light to be incident on the side of the dimming member.

5. It further comprises a prism array (7) having multiple prism sections (71), The optical member according to claim 4, wherein the prism array is attached to the side of the light-adjusting member opposite to the reflective member.

6. The optical member according to Claim 4, wherein the surface of the dimming member opposite to the light guide is defined as the emission surface (3b), the direction along the emission surface in which light is guided by the reflective region and the reflective surface is defined as the light guidance direction, the thickness of the portion of the light guide in which the adhesive surface and the reflective surface face each other is defined as T, the angle of incidence of ambient light (L 1) to the incident surface is defined as θ 2, the width of each of the plurality of regions in the light guidance direction is defined as D, the angle of incidence of light incident on the light guide to the adhesive surface is defined as φ, and the refractive index of the light guide is defined as n, such that 2T・tanφ = 2T・tan(sin -1 (sinθ 2 / n)) ≥ D.

7. Let N be the number of the multiple regions (N: a natural number greater than or equal to 2), and let the region located at the end on the side where the ambient light enters be the first region (31), and let the remaining regions extending from the first region toward the end opposite to the first region be the second to the Nth region (32 to 3N), and let t be the time during which the first region and the Nth region are transparent. １ ,t Ｎ Let the reflectance of the reflective surface be R ｆ The reflectance of the reflective region of the dimming member is R ｍ as, The dimming member satisfies t Ｎ = t １ / (R ｍ （Ｎ－１） × R ｆ （Ｎ－１） ) and is subjected to dimming control, and the optical member according to any one of claims 1 to 6.

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