JP2970487B2 - Fresnel lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Fresnel lens which is mounted on, for example, a window of a vehicle and is used for visually recognizing a blind spot area or the like outside the vehicle compartment from a vehicle interior.

[0002]

2. Description of the Related Art Conventionally, in a visual recognition Fresnel lens for a vehicle for visually recognizing the outside of a vehicle from the interior of the vehicle, when strong disturbance light such as sunlight enters, the disturbance light forms a streak on the lens. It may be difficult to see the image in the direction you want to see.
Therefore, in order to obtain good visibility, the non-lens surface of the Fresnel lens is optimized to totally reflect disturbance light on the non-lens surface, or the disturbance light transmitted through the non-lens surface and reaches the eye point. A disturbance light shielding technology that minimizes the noise has been attempted. As one of them, the non-lens surface angle between the non-lens surface and the Fresnel lens plane is made different according to the number of peaks from the center point of the Fresnel lens to prevent image multiplexing and disturbance light transmission. There is.

[0003]

However, in such a conventional Fresnel lens, the entire circumference of the lens is divided into a plurality of sections in actual production, and non-lens surface angles of different sizes are set in each section. It must be shaped to have. Since the Fresnel lens is manufactured using a mold such as extrusion molding, there is a problem that it is difficult to prepare a mold having such a shape simply and at low cost. There is also a problem that disturbance light is visible when the position of the eye point is shifted. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a Fresnel lens that can obtain a clear image without multiplexing of images and transmission of disturbance light simply and inexpensively in view of such conventional problems.

[0004]

According to the present invention, a non-lens surface of a Fresnel lens which includes a plurality of micro prisms and is disposed between an eye in a predetermined direction and an eye point is provided. The inclination of the angle parallel to the line of sight connecting the reference point and the eye point set on the Fresnel lens, and the light emitted in the direction of the line of sight from inside the micro prism at the reference point is parallel to the optical path traveling through the micro prism. It is assumed that the angle is set between the angle and the angle. The invention according to claim 2 attaches this Fresnel lens to the window of the vehicle and visually recognizes the outside of the vehicle from the eye point in the vehicle interior. A reference point is set on the Fresnel lens in the range, and an angle parallel to the above-mentioned line of sight and an angle parallel to the optical path traveling inside the micro prism are specified using a vector at this reference point.

According to a third aspect of the present invention, in each of the micro prisms, the light totally reflected by the non-lens surface and emitted from the main surface of the lens toward the eye point is incident on the micro prism. A light shield is provided in the incident range. It should be noted that, instead of the incident side, a light shielding body can be provided in the emission range of the main surface of the lens that emits light from the micro prism. According to a fourth aspect of the present invention, a light shielding body is provided in the incident area of the Fresnel lens plane where light emitted from the non-lens surface toward the eye point enters the micro prism. It should be noted that a light blocking member may be provided on the non-lens surface instead of the light incident side.

According to a seventh aspect of the present invention, in a Fresnel lens mounted on a window of a vehicle and visually recognizing the outside of the vehicle from an eye point in the vehicle, a reference point is set on the Fresnel lens and a vector is used. The range in which the light shield is provided is specified in accordance with the shape characteristics of the micro prism. According to a thirteenth aspect of the present invention, there is provided a Fresnel lens body including a plurality of micro prisms, a transparent plate member, a transparent member and an opaque member alternately arranged to form a louver, and the Fresnel lens body. It consists of a layered member sandwiched between the plane side and the flat plate material, and the louver of the layered member reflects light that is totally reflected by the non-lens surface of the Fresnel lens body and emitted from the lens main surface toward the eye point. Light path,
In addition, the optical path of light emitted from the non-lens surface toward the eye point is blocked.
The above-mentioned Fresnel lens body, transparent flat plate material and layered member can be formed of a soft member such as silicon rubber or soft vinyl chloride.

According to a fifteenth aspect of the present invention, in a Fresnel lens mounted on a window of a vehicle and visually recognizing the outside of the cabin from an eye point in the cabin, a reference point is set on the Fresnel lens, and a minute point is set using a vector. The range of the louver angle θL of the layered member is specified according to the shape characteristics of the prism.

[0008]

According to the first aspect, the inclination of the non-lens surface is set between an angle parallel to the line of sight and an angle parallel to the optical path through which light emitted in the line of sight travels through the micro prism. The total luminous flux that reaches the eye point of the light that is pre-reflected by the non-lens surface of the disturbance light toward the eye point and the light that is emitted from the non-lens surface and heads toward the eye point compared to when the angle range is set to another range. , The image multiplexing and disturbance light do not occur when viewed from the eye point. According to the second aspect, by setting the reference point on the Fresnel lens to a range of 60 degrees on both sides around a line drawn directly below the center point of the Fresnel lens, the disturbance light area ratio can be kept small even under daylight. .

According to a third aspect of the present invention, there is provided a light emitting device according to the present invention, wherein the light totally reflected by the non-lens surface and emitted from the main surface of the lens toward the eye point enters the micro prism at the incident range of the Fresnel lens plane. Since the light shielding member is provided, the optical path of the light toward the eye point is blocked, so that multiplexing of images and disturbance light do not occur. In addition, the light can be blocked by providing a light shielding body in the emission range of the main surface of the lens instead of the incident side. According to the fourth aspect of the present invention, since a light-shielding member is provided in the incident area of the Fresnel lens plane where light emitted from the non-lens surface toward the eye point is incident on the micro prism, similarly, disturbance light traveling toward the eye point is generated. Will be shut off.
Alternatively, the light can be blocked by providing a light shield on the non-lens surface instead of the light incident side.

According to a thirteenth aspect, an optical path of light totally reflected by the non-lens surface and emitted from the lens main surface toward the eye point by the louver of the layered member in contact with the Fresnel lens body, and the non-lens surface Since the optical path of the light emitted from the camera toward the eye point is blocked, disturbance light or the like directed to the eye point is blocked.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings by way of examples. First, a first embodiment will be described. FIG. 1 shows an installation layout on a vehicle, in which (a) is a side view of the vehicle, and (b)
Is a rear view. FIG. 2 is an overall front view of the Fresnel lens, and FIG. 3 is a partially enlarged sectional view thereof. As shown in FIG. 1, the Fresnel lens 1 is attached to the window glass 9 from the inside of the vehicle cabin along the upper edge of the rear window of the vehicle 100. Fresnel lens 1
As shown in FIG. 3, a lens main surface 2 which forms an inclined surface with respect to a Fresnel lens plane 4 and a non-lens surface 3 which is continuous with the lens main surface 2 are provided. A base 5 is formed between the intersection of the valleys and the Fresnel lens plane 4. The surface of the Fresnel lens 1 on which the lens main surface 2 is formed faces the eye point E side.

In the general view of FIG. 2, a reference point P is provided at an angle of ω from a line 11 which is directly below the center point L of the Fresnel lens optical axis, and the magnitude of ω is within ± 60 °. Is set to Here, assuming that the positional relationship between the eye point E when the driver of the vehicle turns backward to check the rear and the lens center point L and the reference point P of the Fresnel lens is shown in FIG. L, an eye point E and a plane S including three reference points P
Line 12 on the surface of window glass 9 at reference point P at
Is defined as λ as shown in FIG.

Also, as shown in FIG.
In dimension coordinates XYZ, the coordinates of the lens center point L of the Fresnel lens _{(X L, Y L, Z} L), coordinates of the reference point _{P (X P, Y P,} Z P), the coordinates of the eye point E ( X _E , Y _E , and Z _E ). On the plane of FIG. 5 including the points P, L, and E, the law of refraction is established.

The vector from the point L to the point E is vLE, the vector from the point L to the point P is vLP, the vector from the point P to the point E is vPE, and the vector opposite to the vector of the vLP is vPL. The components of these vectors are as follows: _{vLE = (LE X, LE Y} , LE Z) = (X E -X L, Y E -Y L, Z E -Z L) vLP = (LP X, LP Y, LP Z) = (X P -X _{L, Y P -Y L, Z} P -Z L) = -vPL vPE = (PE X, PE Y, PE Z) = (X E -X P, Y E -Y P, Z E -Z P) ( 1)

Assuming that the angle formed by the points L and E at the point P is ψ2, the magnitude of ψ2 can be obtained from the inner product and the magnitude of these vectors by the following equation. ψ2 = cos ⁻¹ ((vPL, vPE) / | vPL | · | vPE |) (2)

In FIG. 5, point L 'is a point where a horizontal line passing through point L and a perpendicular passing through point P intersect. Since the Y coordinate of the L 'point is equal to the Y coordinate of the P point, the Z coordinate is equal to the Z coordinate of the L point, and the X coordinate is obtained by the following equation since the L' point is on the plane S. _{(Y P -Y L + LE Z} · LP Y / LP Z) LE X / LE Y - (Y P -Y L + LE Z · LP Y / LP Z) LE Z · LP x / (LP Z · LE Y) + X _L (3)

Assuming that a vector from the point P to the point L 'is vPL' and an angle formed by the points L and L 'at the point P is ξ, the magnitude of ξ is expressed by the following equation. ξ = cos ⁻¹ ((vPL, vPL ′) / | vPL | · | vPL ′ |) (4) At this time, the components of the vector of vPL ′ are as follows. _{vPL '= (PL' X,} PL 'Y, PL' Z) = ((Y P -Y L + LE Z · LP Y / LP Z) LE X / LE Y - (Y P -Y L + LE Z · LP Y _{/ LP Z) LE Z · LP} x / (LP Z · LE Y) + X L -X P, 0, Z L -Z P) (5)

From the above, as shown in FIG. 6, the angle θin of the light emitted toward the eye point E from the micro prism at the reference point P with respect to the Fresnel lens plane 4
Is represented by the following equation. θin = {2 +} − (90−λ) = cos ⁻¹ ((vPL, vPE) / | vPL | · | vPE |) + cos ⁻¹ ((vPL, vPL ′) / | vPL | · | vPL ′ |) − ( 90-λ) (6)

The angle θout between the optical path 13 and the Fresnel lens plane 4 when this light travels inside the prism of the Fresnel lens is determined by the angle δ between the lens main surface 2 and the Fresnel lens plane 4 and the refraction of the Fresnel lens material. Using the ratio n and the above θin, it is obtained by the following equation. θout = 90− (δ−sin ⁻¹ (sin (θin− (90−δ)) / n)) (7)

In this embodiment, the angle θ between the non-lens surface 3 and the Fresnel lens plane 4 is defined by the angles θin and θin.
It is set within the range between out. Hereinafter, this will be described. 7 to 10 simulate the reference point P as a micro prism structure. FIG. 7 shows an optical path of light that travels through the prism and is emitted toward the eye point E. The optical path 131 indicates light emitted from the lens principal surface 2 in the direction of the eye point E through the Fresnel lens plane 4 from the direction desired to be viewed. The angle formed by the optical path 131 after being emitted from the prism and the Fresnel lens plane 4 is θin as described above, and the optical path 13 in the prism.
1 and the angle formed by the Fresnel lens plane 4 is θou
t.

In addition, as an optical path emitted from the prism and having an angle θin, there are an optical path 132 totally reflected by the non-lens surface 3 and an optical path 133 emitted from the non-lens surface 3. The light on the optical paths 132 and 133 causes double image and disturbance light.

FIG. 8 shows a case where the value of the angle θ between the non-lens surface 3 and the Fresnel lens plane 4 is within the range of θin and θout. Here, the light emitted from the prism over the range 14 of the optical paths 134 to 136 is the total luminous flux reaching the eye point E. Of these, optical path 13
A range 16 from 4 to 135 is a range from which light incident from a direction desired to be viewed is emitted, and a range 15 from the optical paths 135 to 136 is a range from which light serving as disturbance light is emitted. The ratio between the range 14 and the range 15 (length of the range 15 / range 14
Length), that is, the disturbance light area ratio is such that the value of θ is θin and θ
It does not change if it is within the range of out.

FIG. 9 shows a case where the value of θ is larger than θin. In this case, the size of the range 14 increases to the range 141 as compared with the case of FIG.
Only increases the size of
Does not change. FIG. 10 shows a case where the value of θ is smaller than θout. In this case, the range 14 does not change, and the size of the range 15 increases to the range 152, so that the range 16 narrows to the range 161.

That is, in both cases of FIGS. 9 and 10, the disturbance light area ratio becomes larger than that of FIG. 8, and the case where the value of θ is in the range between θin and θout is the highest. Is smaller. Therefore, in the present embodiment, the angle θ between the non-lens surface 3 and the Fresnel lens plane 4 is set in a range between the angles θin and θout.

Next, the position of the reference point will be described. Here, the degree of influence of the disturbance light area ratio on the visibility will be examined. FIG. 11 shows the sensory evaluation points with respect to the disturbance light area ratio in a daylight environment. The sensory evaluation point “5” is a state where disturbance light cannot be confirmed and can be visually recognized without any problem.
You can see the presence of disturbance light, but you can see it without any problem.
"3" indicates a state in which the presence of disturbance light is clearly recognized but does not affect visual recognition, "2" indicates a state in which the disturbance light is strong, but somehow visible, and "1" indicates a state in which no visible light is visible at all. According to this, when the sensory evaluation point is less than two points, an object to be seen becomes invisible, and the disturbing light area ratio at which the sensory evaluation point changes to less than two points is considered to be 0.
It is between 25 and 0.3.

Hereinafter, specific examples are shown in Table 1. The vehicle A is set for a vehicle having an extremely steep rear window glass 9, and the vehicle B is set for an extremely gentle vehicle.

[Table 1] FIG. 12 shows the disturbance light area ratio on the line 11 (see FIG. 2) drawn directly below the lens center L of the Fresnel lens for the car A and FIG. 13 for the car B. FIGS. 12 and 13 also show the case where ω = 90 °. According to this, when the position of the reference point becomes a position of ω = 60 ° or more in both the car A and the car B, the disturbance light area ratio becomes a value of less than two sensory evaluation points and cannot be visually recognized under daylight. . Therefore, when the reference point P is set within a range of ± 60 ° from the line 12 just below the lens center point L of the Fresnel lens, the situation outside the vehicle compartment can be clearly recognized through the Fresnel lens.

The present embodiment is constructed as described above, and the angle θ between the non-lens surface 3 of the Fresnel lens and the Fresnel lens plane 4 is set with respect to the Fresnel lens plane at the reference point P toward the eye point. Angle θin,
This light falls within the range of the angle θout between the optical path when the light travels inside the prism of the Fresnel lens and the plane of the Fresnel lens, and the reference point P falls within a range of ± 60 ° from a line that is lowered directly below the lens center point L. Since the setting is made, the disturbance light area ratio is minimized without complicating the structure, the disturbance light which affects the multiplexing and the visual recognition of the image is prevented, and a clear image can be obtained.

Next, a second embodiment will be described. In this method, a light-shielding process is performed on an optical path of light that is totally reflected or transmitted through a non-lens surface and travels toward an eye point. First, the optical path of the incident light will be described. FIG. 14 is an enlarged view of a minute prism body constituting the Fresnel lens 1 as in FIG. Now, light coming from the direction to be viewed is incident on the Fresnel lens plane 4 along the optical path 20. At this time, the incident angle is i, and the refraction angle is i ′. Subsequently, the light exits the lens through the lens main surface 2 toward the eye point. At this time, the incident angle with respect to the lens main surface 2 is i ″, and the refraction angle is i ″ ′. Optical path 20 of the emitted light
The angle between the lens and the Fresnel lens plane 4 is defined as θin.

Light incident on the Fresnel lens 1 from a direction different from the optical path 20 is totally reflected by the non-lens surface 3,
It is assumed that there is an optical path 21 of light emitted from the lens main surface 2 in parallel with the optical path 20. The incident angle when the light traveling along the optical path 21 enters the Fresnel lens plane 4 is defined as iG1, and the refraction angle is defined as iG1 '. When this light subsequently enters the non-lens surface 3, the angle between the optical path 21 incident on the non-lens surface 3 and the non-lens surface 3 is defined as iG1 ″.

As shown in FIG. 15, the light emitted from the non-lens surface 3 is such that the angle formed by the emitted light path with the Fresnel lens plane 4 is also θin.
2, the incident angle when the light is incident on the Fresnel lens plane 4 is iG2, and the refraction angle is iG2 '. When light is incident on the non-lens surface 3, the angle between the optical path 22 incident on the non-lens surface 3 and the non-lens surface 3 is iG.
2 ″, the refraction angle when emitted from the non-lens surface 3 is iG
2 "'.

The angles shown in FIGS. 14 and 15 are assumed to be positive, and the angle in the opposite direction is indicated by a negative magnitude. Then, as shown in FIG. 14, the angle formed by the lens main surface 2 and the Fresnel lens plane 4 is δ1, the non-lens surface 3
The angle formed between the lens and the Fresnel lens plane 4 is δ2. The pitch at which the minute prisms are formed is W, and the thickness of the base 5 is t.

Next, the angle of each part is obtained as follows. i ″ ′ = θin−90 + δ1 i ″ = sin−1 (sin (θin−90 + δ1) / n) i ′ = δ1−i ″ iG1 ″ = δ1 + δ2−90−i ″ iG1 ′ = δ1 + 2δ2−sin− ¹ (sin ( θin−90 + δ1) / n) −180 iG2 ″ ′ = θin−90 + δ2 iG2 ″ = 90−sin ⁻¹ (sin (θin−90 + δ2) / n) iG2 ′ = δ2−sin ⁻¹ (sin (90−θin + δ2) / n) (8)

Here, when 90−i ′ ≧ θin and δ2 ≧ 90−i ′ (9), the optical path 21 exists. In the present embodiment, as shown in FIG. 16, the light flux of the optical path 21 is perpendicular to the Fresnel lens plane 4 at the point where the lens principal surface 2 and the non-lens surface 3 intersect at the valley of the Fresnel lens. D1 = tta from the intersection with Fresnel lens plane 4
The light shielding body 30 is provided between the position B1 of the niG1 ′ and the distance K1 represented by the following equation, starting from the position B1. The light-shielding body 30 is realized by, for example, painting the corresponding area in black. K1 = (Wsinδ1 / sin (δ1 + δ2)) siniG1 ″ / sin (iG1 ″ + δ2) (10)

Similarly, if 90−i ′ ≧ θin and δ2 ≦ θin (11), the optical path 22 exists. In the present embodiment, as shown in FIG.
At the valley of the Fresnel lens, the main lens surface 2 and the non-lens surface 3
From the intersection of the perpendicular drawn down to the Fresnel lens plane 4 from the intersection of the fresnel lens plane 4 and D2 = ttaniG
Starting from the position B2 of 2 ′, a distance K2 represented by the following equation
A light shield 31 is provided between them. (Wsinδ1 / sin (δ1 + δ2)) siniG2 ″ / sin (iG2 ″ + δ2) (12) Note that the optical path 21 and the optical path 22 do not exist at the same time.

When δ2 ≧ 90-i ′, as a modification, as shown in FIG. 18, the lens principal surface 2 intersects the lens principal surface 2 at the point where the lens principal surface 2 and the non-lens surface 3 intersect at the peak of the Fresnel lens. Along the distance K3 represented by the following equation:
A light shield 32 may be provided. (Wsinδ1 / sin (δ1 + δ2)) siniG1 ″ / sin (iG1 ″ + 180− (δ1 + δ2)) (13) With this, the light flux in the optical path 21 can be shielded. Further, as a modified example when δ2 ≦ θin, as shown in FIG. 19, a light shielding body 33 can be provided on the non-lens surface 3. This also allows the light flux in the optical path 22 to be shielded.

Rewriting each equation, 90-i ′ ≧ θin
Is sin (θin−90 + δ1) / sin (θin−90) ≧ n (14) δ2 ≧ 90−i ′ is: δ2 ≧ 90−δ1 + sin ⁻¹ (sin (θin−90 + δ1) / n) (15) ttaniG1 ′ Is: tan (δ1 + 2δ2−sin ⁻¹ (sin (θin−90 + δ1) / n) −180) (16)

Equation (10) is given by: (W sin δ 1 / sin (δ 1 + δ 2)) sin (δ ¹ + δ 2−90−sin ⁻¹ (sin (θin−90 + δ 1) / n)) / sin (δ ¹ + 2δ 2−90−sin ⁻¹⁾ (Sin (θin−90 + δ1) / n)) (17) Equation (13) is expressed as (Wsinδ1 / sin (δ1 + δ2)) sin (δ1 + δ2-90-sin ⁻¹ (sin (θin−90 + δ1) / n)) / − cos (sin ^-1 (sin (θin-90 + δ1) / n)) (18) ttaniG2 ′ is ttan (δ2-sin ⁻¹ (sin (90−θin + δ2) / n) (19) Expression (12) Wsinδ1 / sin (δ1 + δ2) ) sin (90- sin -1 (sin (90-θin + δ2) / n)) / sin (90 -sin -1 (sin (90-θin + δ2) / ) + Δ2) becomes (20).

Next, this time, when 90-i '<θin, and δ2 ≧ θin (21), the optical path 21 exists. The optical path 22 emitted from the non-lens surface 3 does not occur. In the present embodiment, as shown in FIG. 20, for the light flux in the optical path 21, at the valley of the Fresnel lens, a perpendicular drawn from the point where the lens principal surface 2 intersects the non-lens surface 3 to the Fresnel lens plane 4 and the Fresnel lens From the intersection with the plane 4, D5 = ttaniG1 '
The light shielding body 34 is provided between the position B5 and the distance K5 represented by the following equation. (Wsinδ1 / sin (δ1 + δ2)) siniG1 ″ / sin (iG1 ″ + δ2) (22)

If 90−i ′ <θin and δ2 ≦ 90−i ′ (23), the optical path 22 exists, and the optical path 21 totally reflected by the non-lens surface 3 does not occur. In the present embodiment, as shown in FIG. 21, a perpendicular line lowered from the point where the lens principal surface 2 intersects the non-lens surface 3 to the Fresnel lens plane 4 at the valley of the Fresnel lens and the Fresnel lens plane The light shielding body 35 is provided between a distance B6 represented by the following equation starting from a position B6 of D6 = ttaniG2 ′ from the intersection with the distance D4. (Wsinδ1 / sin (δ1 + δ2)) siniG2 ″ / sin (iG2 ″ + δ2) (24)

When δ2 ≧ θin, as a modification, as shown in FIG. 22, the lens principal surface 2 and the non-lens surface 3 intersect at the crest of the Fresnel lens.
Along the distance up to a distance K7 represented by the following equation. (Wsinδ1 / sin (δ1 + δ2)) siniG1 ″ / sin (iG1 ″ + 180− (δ1 + δ2)) (25) With this, the light flux in the optical path 21 can be shielded. Further, as a modified example when δ2 ≦ 90−i ′, a light shielding body 37 can be provided on the non-lens surface 3 as shown in FIG. This also enables the light path 22 to be shielded.

Next, if θin>δ2> 90-i ′ (26), both the optical path 21 and the optical path 22 exist. In particular, in the case of iG1′−iG2 ′ <0 (27), when there is a relationship of the following equation, by providing a light-shielding body in the following region, it is possible to shield both the optical path 21 and the optical path 22. . ttaniG2 ′ ≦ (Wsinδ1 / sin (δ1 + δ2)) sin iG1 ″ / sin (iG1 ″ + δ2) + ttaniG1 ′ (28)

That is, as shown in FIG. 24, at the valley portion of the Fresnel lens, D9 is determined from the intersection of the perpendicular drawn down from the point where the lens principal surface 2 and the non-lens surface 3 intersect to the Fresnel lens plane 4 and the Fresnel lens plane 4. The light shielding body 38 is provided between the position B9 of = ttaniG1 'as a starting point and a position J9 represented by the following equation. J9 = (Wsinδ1 / sin (δ1 + δ2)) siniG2 ″ / sin (iG2 ″ + δ2) + ttaniG2 ′ (29)

In the case of θin>δ2> 90-i ′ and iG1′−iG2 ′ <0 (30), when there is a relation of the following equation, by providing a light-shielding body in the following area, Each of the optical paths 21 and 22 can be shielded from light. ttaniG2 ′> (Wsinδ1 / sin (δ1 + δ2)) sin iG1 ″ / sin (iG1 ″ + δ2) + ttaniG1 ′ (31) That is, as shown in FIG. The perpendicular drawn from the point where 3 intersects to the Fresnel lens plane 4 and the Fresnel lens plane 4
The light shielding body 39 is provided at a distance K10 represented by the following equation starting from the position B10 of D10 = ttaniG1 'from the intersection with. (Wsinδ1 / sin (δ1 + δ2)) siniG1 ″ / sin (iG1 ″ + δ2) + ttaniG1 ′ (32) Thereby, the light flux in the optical path 21 can be shielded.

Further, a position B11 of D11 = ttaniG2 'is determined from the intersection of the perpendicular drawn down to the Fresnel lens plane 4 from the intersection of the lens principal surface 2 and the non-lens surface 3 at the valley of the Fresnel lens and the Fresnel lens plane 4. As a starting point, the light shielding body 40 is provided between the distances K11 represented by the following equation. (Wsinδ1 / sin (δ1 + δ2)) siniG2 ″ / sin (iG2 ″ + δ2) (33) Thereby, the light beam in the optical path 22 can be shielded.

As a modified example of the general case where θin>δ2> 90-i ′, as shown in FIG. 26, the lens principal surface 2 and the non-lens surface 3 intersect at the crest of the Fresnel lens. Along the surface 2, a distance K expressed by the following equation
Between 12 and the non-lens surface 3, a light shielding body 41 can be provided. (Wsinδ1 / sin (δ1 + δ2)) siniG1 ″ / sin (iG1 ″ + 180− (δ1 + δ2)) (34) With this, the light beams in the optical paths 21 and 22 can be shielded.

Rewriting each equation, 90-i '<θin
Is sin (θin−90 + δ1) / sin (θin−90) <n (35) δ2 ≦ 90−i ′ is δ2 ≦ 90−δ1 + sin ⁻¹ (sin (θin−90 + δ1) / n) (36) θin>δ2> 90−i ′ is θin>δ2> 90−δ1 + sin ⁻¹ (sin (θin−90 + δ1) / n) (37) iG1′−iG2 ′ <0 is δ1 + δ2−sin ⁻¹ (sin (θin− 90 + δ1) / n) + sin ⁻¹ (sin (θin−90 + δ2) / n) −180 <0 (38)

The equation (28) is expressed as follows: tan (δ2−sin ⁻¹ (sin (90−θin + δ2) / n) ≦ (Wsinδ1 / sin (δ1 + δ2)) sin (δ1 + δ2−90−sin ⁻¹ (sin (θin −90 + δ1) / n)) / sin (δ1 + 2δ2-90−sin ⁻¹ (sin (θin−90 + δ1) / n)) + ttan (δ1 + 2δ2-sin− ¹ (sin (θin−90 + δ1) / n) −180) ( 39) Equation (31) is given by: tan (δ2−sin ⁻¹ (sin (90−θin + δ2) / n)> (Wsinδ1 / sin (δ1 + δ2)) sin (δ1 + δ2−90−sin ⁻¹ (sin (θin−90 + δ1)) / n)) / sin (δ1 + 2δ2-90-sin -1 (sin (θin-90 + δ1) / n)) + ttan (δ1 + 2δ2-sin -1 (sin θin-90 + δ1) / n) -180) becomes (40). Others, formula (16) to (20 above) are also applicable similarly.

The present embodiment is constructed as described above, and a light shielding body is provided on the optical path of the light heading to the eye point after being totally reflected or transmitted through the non-lens surface. Multiplexing and disturbance light are prevented, and a clear image can be obtained.

Next, a third embodiment of the present invention will be described. This is obtained by adding a louver to a lens member. FIG.
FIG. 7 is a perspective view showing a part of the Fresnel lens 10 of the present embodiment in a cutaway manner. The Fresnel lens body 50 is shown in FIG.
As shown in FIG. 8, the lens principal surface 2
And a non-lens surface 3 and a Fresnel lens plane 4. A transparent plate member 60 made of a self-adsorbing member is provided so as to face the Fresnel lens plane 4 side, and a transparent member and an opaque member alternate between the Fresnel lens body 50 and the plate member 60. Layered member 70 is sandwiched. In the layered member 70, the transparent member and the opaque member are linearly arranged, and a louver 70L is formed. Soft members such as silicon rubber and soft vinyl chloride can be used as the Fresnel lens body, the flat plate member, and the layered member.

FIG. 28 is a partially enlarged sectional view. The Fresnel lens 10 includes the transparent member of the layered member 70 and the flat plate 6.
Numeral 0 has the same refractive index as the Fresnel lens body 50, and corresponds to a Fresnel lens 1 shown in FIG. Therefore, one reference point is set on the Fresnel lens, and on a plane formed by the reference point, the eye point, and the optical axis center point of the Fresnel lens, the same relational expression as described in the first embodiment is applied between the angles. To establish.

Here, in the micro prism shown in FIG. 28, in order for the light in the optical path 20 to pass through this prism and exit to the eye point side, the visible angle of the louver 70L is α, and the louver angle θL is , I′−α / 2 ≦ θL ≦ i ′ + α / 2 (41). This can be rewritten as follows. δ1−sin ⁻¹ (sin (θin−90 + δ1) / n) −α / 2 ≦ θL ≦ δ1−sin ⁻¹ (sin (θin−90 + δ1) / n) + α / 2 (42) FIG. Lower limit θL = δ1−sin ⁻¹ (sin (θin−90 + δ1)
/ N) -α / 2, and FIG. 30 shows the upper limit of the louver angle θL = δ1−sin ⁻¹ (sin (θin−90 + δ1)).
/ N) + α / 2.

Here, 90−i ′ ≧ θin and δ2 ≧ 9
In the case of 0-i ′, as shown in FIG. 31, the optical path 21 totally reflecting the non-lens surface 3 is generated, but if α / 2−θL ≦ iG1 ′ (43), the light flux in the optical path 21 is It is shaded. FIG. 32 shows this state. In the figure, the optical path indicated by a broken line indicates a state in which the traveling is blocked by the louver of the layered member 70. When 90−i ′ ≧ θin and δ2 ≦ θin, as shown in FIG. 33, an optical path 22 that transmits through the non-lens surface 3 is generated, but if α / 2−θL ≦ iG2 ′ (44) The light beam in the optical path 22 is shielded.

If equation (43) is rewritten, α / 2−θL <δ1 + 2δ2−180−sin ⁻¹ (sin (θin−90 + δ1) / n) (45) Equation (44) indicates that α / 2−θL < δ2−sin ⁻¹ (sin (θin−90 + δ2) / n) (46) In addition, Expressions (14) and (15) are similarly applied.

Next, when 90-i '<θin, δ2 ≧ θ
In the case of in, as shown in FIG.
Is generated, but if α / 2−θL ≦ iG1 ′ (43), the light flux in the optical path 21 is blocked. Also, 90-
When i ′ <θin and δ2 ≦ 90−i ′, FIG.
As shown in (5), an optical path 22 that passes through the non-lens surface 3 is generated. However, if α / 2−θL ≦ iG2 ′ (44), the light beam in the optical path 22 is shielded.

Further, if θin>δ2> 90-i ′, both the optical path 21 and the optical path 22 occur, but as shown in FIG. 36, when iG1′−iG2 ′ <0, α / 2−90 If θL ≦ iG1 ′ (43), the light beams in the optical paths 21 and 22 are blocked. Again, each of the rewritten expressions is the expression (1
4), (36) to (38), (45) and (46) apply similarly.

The present embodiment is constructed as described above. A layered member 70 forming a louver is sandwiched between the Fresnel lens body 50 and the flat plate member 60, and the louver angle θL and its visible angle α are defined by a predetermined relational expression. Since the setting is made to satisfy the condition, a clear image can be obtained without multiplexing images or generating disturbance light. Further, since the flat plate member 60 is made of a self-adsorbing member, the Fresnel lens body, the layered member and the flat plate member 60 can be integrally treated, and can be easily attached to the window glass similarly to a single Fresnel lens. Can be.

FIG. 3 shows a method for manufacturing the above-mentioned layered member.
This will be described with reference to FIGS. First, as shown in FIG. 37A, transparent plates 90 and opaque plates 91 made of a soft material such as silicone rubber or soft vinyl chloride are alternately laminated and bonded to form a rectangular parallelepiped block 92. When the rectangular parallelepiped block 92 reaches a certain height, the support portion 93 is bonded to a surface perpendicular to the laminating direction, as shown in FIG.
Next, the rectangular parallelepiped block 92 is attached to the slicer so that it faces downward. At this time, as shown in FIG. 38, the entire block including the rectangular parallelepiped block 92 and the support portion 93 is installed at an angle of the louver angle θL, and sliced thinly horizontally. As shown in FIG. Can be.

By the way, since the supporting portion 93 has been made of metal so far, when the blade of the slicing machine reaches the position corresponding to the supporting portion 93 as shown in FIG. Discard the part. Therefore, as a first method, a support 93A made of a material having substantially the same quality or hardness as the rectangular parallelepiped block 92, for example, a material such as silicon rubber or vinyl chloride is used as the support, and as shown in FIG. 9
By slicing every 3A, a rectangular parallelepiped block 92 is obtained.
The layered member 70 having the louver angle θL can be manufactured without leaving any problem.

When slicing the entire block, the entire block is distorted due to its own weight of the rectangular parallelepiped block 92. If it is difficult to reproduce an accurate louver angle, as shown in FIG. By forming the supporting portion as a supporting portion 93B made of a material having substantially the same or substantially the same hardness as the rectangular parallelepiped block 92 and extending to an adjacent surface, as shown in FIG. By slicing the support portion 93B together, the distortion of the rectangular parallelepiped block 92 can be reduced, and the layered member 70 having the louver angle θL can be left without leaving the rectangular parallelepiped block 92.
Can be.

As a second method, as shown in FIG. 43 (a), the support portion 94 is made divisible, and when the blade of the slicing machine comes to a position where it comes into contact with the support portion 94, FIG. By removing the endmost support portion 94a as shown in FIG.
By sequentially repeating this, the layered member 70 having the louver angle θL can be formed without leaving the rectangular parallelepiped block 92.

Further, since the entire block is tilted when slicing, the entire block is distorted due to its own weight of the rectangular parallelepiped block 92, and even if it is difficult to reproduce an accurate louver angle, as shown in FIG. By attaching the support part 95 which can be divided similarly to the surface adjacent to 94, the distortion of the rectangular parallelepiped block 92 can be reduced. Then, when the blade of the slicing machine comes to a position where it hits the upper surface support portion or the side surface support portion as shown in (b) of the same figure, by removing the end upper surface support portion 94a or the side surface support portion 95a, You will be able to slice further. Thereby, the rectangular parallelepiped block 9
2 can be reduced, and the layered member 70 having the louver angle θL can be formed without leaving the rectangular parallelepiped block.

As a third method, after forming the rectangular parallelepiped block 92, as shown in FIG. 45A, the surface 9 having a louver angle θL with respect to the laminating direction is formed.
Then, the supporting portion 97 is bonded to the cut surface 96 in advance. This is mounted on a slicing machine so that the cut surface 96 is horizontal, and sliced thinly horizontally. As a result, the layered member 70 having a louver angle θL as shown in FIG.
Can be.

In the above embodiment, the transparent member and the opaque member of the layered member 70 form a linear louver, but instead of the layered member 70,
As shown in FIG. 46, a Fresnel lens 10A using a layered member 80 in which a transparent member and an opaque member are concentrically arranged may be used. In this case, the center point L of the Fresnel lens body 50 and the center of the concentric circle of the layered member 80 are matched. This also prevents unnecessary disturbance light from entering the Fresnel lens body near the reference point, as in the case of the linear louver, as shown in FIG.

[0064]

As described above, according to the present invention, in a Fresnel lens having a plurality of micro prisms, the inclination of the non-lens surface, the angle parallel to the line of sight, and the light emitted in the direction of the line of sight travel in the micro prism. Since the angle was set between the optical path and the parallel angle, the ratio (disturbance light area ratio) of the total luminous flux such as disturbance light toward the eye point can be minimized as compared with other angles. This has the effect of preventing multiplexing of images and disturbance light that affect the visual recognition of the object through the Fresnel lens. Further, by setting the reference point in a range of 60 degrees on both sides around a line drawn directly below the center point of the Fresnel lens, the disturbance light area ratio can be kept small even under daylight.

A Fresnel lens plane on which light totally reflected by the non-lens surface and emitted from the main lens surface toward the eye point or light emitted from the non-lens surface toward the eye point enters the micro prism. By providing a light-shielding body in the incident range, an optical path of disturbance light or the like toward the eye point is blocked, and an effect of preventing multiplexing of images and disturbance light is obtained.

Further, the Fresnel lens is composed of a Fresnel lens body having a plurality of micro prisms, a transparent flat plate, and a layered member forming a louver sandwiched therebetween, and the louver is formed of the Fresnel lens body. The optical path of light totally reflected by the non-lens surface and emitted from the lens main surface toward the eye point, and the optical path of light emitted from the non-lens surface toward the eye point may be blocked. In addition, an optical path of disturbance light or the like toward the eye point is blocked, and an effect of preventing multiplexing of images and disturbance light is obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an installation layout of a Fresnel lens on a vehicle.

FIG. 2 is an overall front view of the Fresnel lens.

FIG. 3 is a partially enlarged sectional view of a Fresnel lens.

FIG. 4 is a diagram illustrating a positional relationship among an eye point, a lens center point, and a reference point.

FIG. 5 is a diagram showing the inclination of a tangent to a window glass surface at a reference point.

FIG. 6 is a diagram showing an optical path in a micro prism of a Fresnel lens.

FIG. 7 is a diagram showing optical paths of various lights that travel inside the micro prism and are emitted toward the eye point.

FIG. 8 is a diagram showing a setting range of an angle between a non-lens surface and a Fresnel lens plane in the first embodiment.

FIG. 9 is a diagram illustrating a comparative example in which an angle between a non-lens surface and a Fresnel lens plane is larger than a set range.

FIG. 10 is a diagram illustrating a comparative example when an angle between a non-lens surface and a Fresnel lens plane is smaller than a set range.

FIG. 11 is a diagram showing the degree of influence of the disturbance light area ratio on visibility.

FIG. 12 is a diagram showing a change in a disturbance light area ratio depending on a position of a reference point.

FIG. 13 is a diagram showing a change in a disturbance light area ratio depending on a position of a reference point.

FIG. 14 is an enlarged view of a micro prism illustrating an optical variable in the second embodiment.

FIG. 15 is an enlarged view of a micro prism illustrating an optical variable in the second embodiment.

FIG. 16 is a diagram showing an installation range of a light shield under specification conditions in which an optical path totally reflected by a non-lens surface is used in the second embodiment.

FIG. 17 is a diagram showing an installation range of a light shield under specification conditions where an optical path transmitting through a non-lens surface is provided in the second embodiment.

FIG. 18 is a diagram showing a modification of the installation range of the light shield when there is an optical path totally reflected by the non-lens surface.

FIG. 19 is a diagram showing a modification of the installation range of the light shield when there is an optical path transmitting through the non-lens surface.

FIG. 20 is a diagram illustrating an installation range of a light shielding body under another specification condition having an optical path totally reflected by a non-lens surface.

FIG. 21 is a diagram illustrating an installation range of a light shield under another specification condition having an optical path transmitting through a non-lens surface.

FIG. 22 is a diagram showing another modification of the light-shielding member installation range when there is an optical path that is totally reflected by the non-lens surface.

FIG. 23 is a diagram showing another modification of the light-shielding body installation range when there is an optical path transmitting through the non-lens surface.

FIG. 24 is a diagram illustrating an installation range of a light shield under specification conditions where there is an optical path that is totally reflected by a non-lens surface and an optical path that is transmitted;

FIG. 25 is a diagram illustrating an installation range of a light shield under another specification condition in which an optical path totally reflected by a non-lens surface and an optical path transmitted therethrough.

FIG. 26 is a diagram showing another modification of the light-shielding body installation range when there is an optical path totally reflected by the non-lens surface and an optical path to be transmitted;

FIG. 27 is a partially cutaway perspective view showing the Fresnel lens of the third embodiment.

FIG. 28 is a partially enlarged sectional view of the third embodiment.

FIG. 29 is a diagram showing an optical path at the time of the lower limit of the louver angle.

FIG. 30 is a diagram showing an optical path when the louver angle is at an upper limit.

FIG. 31 is a diagram illustrating a relationship between a louver angle and a louver angle under a specification condition in which an optical path totally reflected by a non-lens surface is present.

FIG. 32 is a diagram showing a state in which an optical path is blocked by a louver.

FIG. 33 is a diagram showing a relationship between a louver visible angle and a louver angle under a specification condition having an optical path transmitting through a non-lens surface.

FIG. 34 is a diagram showing the relationship between the louver viewing angle and the louver angle under another specification condition where there is an optical path totally reflected by the non-lens surface.

FIG. 35 is a diagram showing the relationship between the visible angle of the louver and the louver angle under another specification condition having an optical path transmitting through the non-lens surface.

FIG. 36 is a diagram showing the relationship between the louver visible angle and the louver angle under a specification condition in which there is an optical path totally reflected by the non-lens surface and an optical path transmitted therethrough.

FIG. 37 is an explanatory diagram showing a procedure for preparing a material in producing a layered member.

FIG. 38 is an explanatory view showing how to attach a raw material to a slicer in producing a layered member.

FIG. 39 is an explanatory view showing a procedure for slicing a material.

FIG. 40 is a diagram showing a slice limit when the support is made of metal.

FIG. 41 is an explanatory diagram showing a slicing procedure in a first method of forming a layered member.

FIG. 42 is an explanatory diagram showing a modification of the slice procedure in the first method.

FIG. 43 is an explanatory view showing a material and a slice procedure in the second method.

FIG. 44 is an explanatory diagram showing a modification of the slice procedure in the second method.

FIG. 45 is an explanatory diagram showing a material and a slicing procedure in the third method.

FIG. 46 is a partially cutaway perspective view showing a modification of the Fresnel lens in the third example.

FIG. 47 is a partially enlarged sectional view of a modification.

[Explanation of symbols]

1, 10, 10A Fresnel lens 4 Fresnel lens plane 2 Lens principal surface 3 Non-lens surface 5 Base 9 Window glass 30-41 Light shield 50 Fresnel lens body 60 Flat plate 70, 80 Layered member 70L Louver 90 Transparent plate 91 Opaque plate 92 rectangular parallelepiped block 93, 93A, 93B, 94, 95 support part E eye point L center point of Fresnel lens P reference point λ inclination of tangent θin light exit angle from lens principal surface to eye point θout light toward light point Angle at which the light travels through the prism θ Angle between the non-lens surface and the Fresnel lens plane W Pitch of the micro prism t Thickness of the base part α Visible angle of louver θL Louver angle

Claims (22)

(57) [Claims] 1. A Fresnel lens having a plurality of micro prisms and disposed between a viewing target and an eye point in a predetermined direction, the inclination of a non-lens surface is determined by setting a reference point and an eye point set on the Fresnel lens. A Fresnel lens wherein an angle parallel to the line of sight to be connected and an angle parallel to an optical path through which light emitted in the direction of the line of sight from inside the micro prism at the reference point travels inside the micro prism. . 2. A Fresnel lens equipped with a plurality of micro prisms and mounted on a window of a vehicle and visually recognizing the outside of the cabin from an eye point in the cabin, wherein both sides are 60 degrees centered on a line that is directly below the Fresnel lens center point. sets the reference point on the Fresnel lens range of coordinates of the Fresnel lens center point _{(X L, Y L, Z} L), the coordinates of the reference point (X _P,
Y _P , Z _P ) and the coordinates of the eye point are (X _E , Y _E , Z
_E ), and the angle between a tangent to the mounting surface at the reference point on the plane including the reference point, the eye point, and the center point of the Fresnel lens and the line of sight connecting the reference point and the eye point is λ, and a cross section on the plane Where δ is the angle between the lens main surface of the micro prism and the Fresnel lens plane, and n is the refractive index of the Fresnel lens material, θin = cos ⁻¹ ((vPL, vPE) / | vPL | ·
| VPE |) + cos ^-1 ((vPL, vPL ') / | v
PL | · | vPL ′ |) − (90−λ) θout = 90− (δ−sin ⁻¹ (sin (θin−
(90-δ)) / n )) However, (vPL, vPE) = ( X L -X P) (X E -X P) +
(Y _L −Y _P ) (Y _E −Y _P ) + (Z _L −Z _P ) (Z _{E
-Z P) | vPL | = (} (X L -X P) 2 + (Y L -Y P) 2 +
(Z _L −Z _P ) ² ) ^1/2 | vPE | = ((X _E −X _P ) ² + (Y _E −Y _P ) ² +
^{_{(Z E -Z P) 2)}} 1/2 (vPL, vPL ') = (X L over ^{_{X P) 2 + (Z L}} -Z
^{_{P) 2 | vPL '| =}} ((X L -X P) 2 + (Z L -
Z _P ) ² ) As ^1/2 , the angle between the non-lens surface and the Fresnel lens plane is
A Fresnel lens which is set between θin and θout. 3. A Fresnel lens comprising a plurality of microprisms and disposed between an object to be viewed in a predetermined direction and an eye point. A Fresnel lens characterized in that a light shielding body is provided in the incident area of the Fresnel lens plane where light emitted toward a point enters the micro prism. 4. A Fresnel lens comprising a plurality of microprisms and disposed between a viewing object in a predetermined direction and an eye point, wherein light emitted from each non-lens surface of the micro prism toward the eye point. Wherein a light-shielding member is provided in the incident range of the plane of the Fresnel lens which enters the micro prism. 5. A Fresnel lens comprising a plurality of microprisms and disposed between an object to be viewed in a predetermined direction and an eye point. A Fresnel lens, wherein a light-shielding body is provided in the emission area of the lens main surface where light emitted toward the point is emitted from the micro prism. 6. A Fresnel lens comprising a plurality of microprisms and disposed between an object to be viewed in a predetermined direction and an eye point, wherein each microprism is provided with a light shield on a non-lens surface. The Fresnel lens according to claim 3. 7. A Fresnel lens provided with a plurality of micro prisms and mounted on a window of a vehicle and visually recognizing the outside of the vehicle from an eye point in the vehicle interior, wherein a reference point is set on the Fresnel lens and coordinates of a center point of the Fresnel lens. the _{(X L, Y L, Z} L), the coordinates of the reference point _{(X P, Y P, Z} P), the coordinates of the eye point (X _E,
Y _E , Z _E ), and the angle between a tangent to the mounting surface at the reference point on a plane including the reference point, the eye point, and the center point of the Fresnel lens and a viewing direction connecting the reference point and the eye point is λ, The angle between the lens principal surface of the micro prism and the Fresnel lens plane in a cross section in the plane is δ.
1. The angle between the non-lens surface and the Fresnel lens plane is δ2,
The thickness of the base portion is t, the refractive index of the Fresnel lens material is n, the pitch between the micro prisms is W, and θin = cos ⁻¹ ((vPL, vPE) / | vPL | ·
| VPE |) + cos ^-1 ((vPL, vPL ') / | v
PL | · | vPL ′ |) − (90−λ) θout = 90− (δ−sin ⁻¹ (sin (θin−
(90-δ)) / n )) However, (vPL, vPE) = ( X L -X P) (X E -X P) +
(Y _L −Y _P ) (Y _E −Y _P ) + (Z _L −Z _P ) (Z _{E
-Z P) | vPL | = (} (X L -X P) 2 + (Y L -Y P) 2 +
(Z _L −Z _P ) ² ) ^1/2 | vPE | = ((X _E −X _P ) ² + (Y _E −Y _P ) ² +
^{_{(Z E -Z P) 2)}} 1/2 (vPL, vPL ') = (X L -X P) 2 + (Z L -Z
^{_{P) 2 | vPL '| =}} ((X L -X P) 2 + (Z L -
Z _P ) ² ) ^1/2 , the micro prism is: (A1) sin (θin−90 + δ1) / sin (θin−9)
0) ≧ n and δ2 ≧ 90−δ1 + sin ⁻¹ (sin (θin−90 +
δ1) / n) or (A2) sin (θin−90 + δ1) / sin (θin−9)
0) <n and δ2 ≧ θin, the condition A of the Fresnel lens plane is defined as ttan (δ1 + 2δ2 −sin ⁻¹ (sin (θin−
90 + δ1) / n) −180) as the starting point, (Wsinδ1 / sin (δ1 + δ2)) sin (δ1
+ Δ2−90−sin ⁻¹ (sin (θin−90 + δ
1) / n)) / sin (δ1 + 2δ2-90−sin ⁻¹⁾
(Sin (θin−90 + δ1) / n)) A Fresnel lens characterized in that a light-shielding member is provided between the distances indicated by: 8. Instead of providing a light shield on the plane of the Fresnel lens, (Wsin δ1 / sin (δ1 + δ2)) sin (δ1) along the lens main surface from the point where the lens main surface and the non-lens surface intersect at the peak.
+ Δ2−90−sin ⁻¹ (sin (θin−90 + δ
1) / n)) /-cos (sin ^-1 (sin (θin-
The Fresnel lens according to claim 7, wherein a light-shielding member is provided between the distances represented by 90 + δ1) / n)). 9. The method according to claim 1, wherein the micro prism is in the following condition: (B1) sin (θin−90 + δ1) / sin (θin−9)
0) ≧ n and δ2 ≦ θin or (B2) sin (θin−90 + δ1) / sin (θin−9)
0) <n and δ2 ≦ 90−δ1 + sin ⁻¹ (sin (θin−90 +
When the condition B of δ1) / n) is satisfied, ttan (δ2−sin ^{−) is} determined from the intersection of the Fresnel lens plane with the vertical line lowered from the point where the lens principal surface and the non-lens surface intersect at the valley to the Fresnel lens plane. ¹ (sin (90−θin + δ
Starting from the position 2) / n), (Wsinδ1 / sin (δ1 + δ2)) sin (90
−sin ⁻¹ (sin (90−θin + δ2) / n)) /
sin (90−sin ⁻¹ (sin (90−θin + δ
The Fresnel lens according to claim 7, wherein a light shielding body is provided between the distances represented by 2) / n) + δ2). 10. The micro prism, instead of the condition A, is defined as sin (θin−90 + δ1) / sin (θin−9).
0) <n and θin>δ2> 90− (δ1−sin ⁻¹ (sin (θi
n−90 + δ1) / n) and δ1 + δ2-sin ⁻¹ (sin (θin−90 + δ1)
/ N) + sin ^-1 (sin (θin−90 + δ2) /
n) −180 <0 and tan (δ2−sin ⁻¹ (sin (90−θin + δ)
2) / n) ≦ (Wsinδ1 / sin (δ1 + δ2))
sin (δ1 + δ2-90−sin ⁻¹ (sin (θin
−90 + δ1) / n)) / sin (δ1 + 2δ2-90
−sin ⁻¹ (sin (θin−90 + δ1) / n)) +
ttan (δ1 + 2δ2-sin ⁻¹ (sin (θin−
90 + δ1) / n) −180) When the condition C is satisfied, the point of intersection of the Fresnel lens plane with the perpendicular drawn down to the Fresnel lens plane from the intersection of the lens principal surface and the non-lens surface at the valley is ttan (δ1 + 2δ2). −sin ⁻¹ (sin (θin−
(Wsinδ1 / sin (δ1 + δ2)) sin (90)
−sin ⁻¹ (sin (90−θin + δ2) / n)) /
sin (90−sin ⁻¹ (sin (90−θin + δ
2) / n) + δ2) + ttan (δ2-sin ⁻¹ (si
8. The Fresnel lens according to claim 7, wherein a light shielding body is provided up to a position indicated by n (90-θin + δ2) / n). 11. The micro prism according to claim 1, wherein sin (θin−90 + δ1) / sin (θin−9)
0) <n and θin>δ2> 90− (δ1−sin ⁻¹ (sin (θi
n−90 + δ1) / n) and δ1 + δ2-sin ⁻¹ (sin (θin−90 + δ1)
/ N) + sin ^-1 (sin (θin−90 + δ2) /
n) −180 <0 and tan (δ2−sin ⁻¹ (sin (90−θin + δ)
2) / n)> (Wsinδ1 / sin (δ1 + δ2))
sin (δ1 + δ2-90−sin ⁻¹ (sin (θin
−90 + δ1) / n)) / sin (δ1 + 2δ2-90
−sin ⁻¹ (sin (θin−90 + δ1) / n)) +
ttan (δ1 + 2δ2-sin ⁻¹ (sin (θin−
90 + δ1) / n) −180) When the condition D is satisfied, the point of intersection of the Fresnel lens plane with the perpendicular drawn down to the Fresnel lens plane from the intersection of the lens principal surface and the non-lens surface at the valley is ttan (δ1 + 2δ2). −sin ⁻¹ (sin (θin−
90 + δ1) / n) −180) as the starting point, (Wsinδ1 / sin (δ1 + δ2)) sin (δ1
+ Δ2−90−sin ⁻¹ (sin (θin−90 + δ
1) / n)) / sin (δ1 + 2δ2-90−sin ⁻¹⁾
(Sin (θin−90 + δ1) / n)) and between the Fresnel lens plane
From the point of intersection between the lens principal surface and the non-lens surface at the valley and the perpendicular drawn down to the Fresnel lens plane, ttan (δ2-sin ⁻¹ (sin (90−θin + δ)
Starting from the position 2) / n), (Wsinδ1 / sin (δ1 + δ2)) sin (90
−sin ⁻¹ (sin (90−θin + δ2) / n)) /
sin (90−sin ⁻¹ (sin (90−θin + δ
The Fresnel lens according to claim 7, wherein a light shielding body is provided between the distances represented by 2) / n) + δ2). 12. The micro prism may be replaced by sin (θin−90 + δ1) / sin (θin−9) instead of the condition A.
0) <n and θin>δ2> 90− (δ1−sin ⁻¹ (sin (θi
When the condition E of n−90 + δ1) / n) is satisfied, (Wsinδ1 / sin (δ1 + δ2)) along the lens main surface from the point where the lens main surface and the non-lens surface of the Fresnel lens plane intersect at the peak. sin (δ1
+ Δ2−90−sin ⁻¹ (sin (θin−90 + δ
1) / n)) /-cos (sin ^-1 (sin (θin-
The Fresnel lens according to claim 7, wherein a light-shielding member is provided for a distance indicated by 90 + δ1) / n)) and on a non-lens surface. 13. A Fresnel lens disposed between a viewing target in a predetermined direction and an eye point, the Fresnel lens body including a plurality of micro prisms, a transparent flat plate, a transparent member and an opaque member. Are alternately arranged to form a louver, and a layer member sandwiched between the Fresnel lens plane side of the Fresnel lens body and a flat plate material, and the louver of the layer member is a non-lens surface of the Fresnel lens body. It is characterized in that it is configured to block an optical path of light totally reflected and emitted from the lens main surface toward the eye point and an optical path of light emitted from the non-lens surface toward the eye point. Fresnel lens. 14. The Fresnel lens body, claim transparent flat plate material and the layered member, characterized in that the silicone rubber, and is formed of a soft member softer vinyl chloride or the like 1
3. The Fresnel lens according to 3 . 15. A Fresnel lens body having a plurality of micro prisms, a transparent flat plate, and a transparent member and an opaque member are alternately arranged to form a louver. A Fresnel lens, which is a layered member sandwiched between a flat plate material and is mounted on a window of a vehicle and visually recognizes the outside of the vehicle from an eye point in the vehicle, wherein the coordinates of the center point of the Fresnel lens are represented by ( _XL ,
Y _L , Z _L ), the coordinates of the reference point are (X _P , Y _P , Z _P ),
The coordinates of the eye point are (X _E , Y _E , Z _E ), and a tangent to the mounting surface at the reference point on a plane including the reference point, the eye point, and the center point of the Fresnel lens is connected to the reference point and the eye point. Let λ be the angle with the line of sight, δ1 be the angle between the lens principal surface of the micro prism and the Fresnel lens plane in the cross section in the plane, δ2 be the angle between the non-lens surface and the Fresnel lens plane, and the refractive index of the Fresnel lens material Is defined as n, and θin = cos ⁻¹ ((vPL, vPE) / | vPL | ·
| VPE |) + cos ^-1 ((vPL, vPL ') / | v
PL | · | vPL '|) - (90-λ) However, (vPL, vPE) = ( X L -X P) (X E -X P) +
(Y _L −Y _P ) (Y _E −Y _P ) + (Z _L −Z _P ) (Z _{E
-Z P) | vPL | = (} (X L -X P) 2 + (Y L -Y P) 2 +
(Z _L −Z _P ) ² ) ^1/2 | vPE | = ((X _E −X _P ) ² + (Y _E −Y _P ) ² +
^{_{(Z E -Z P) 2)}} 1/2 (vPL, vPL ') = (X L -X P) 2 + (Z L -Z
^{_{P) 2 | vPL '| =}} ((X L -X P) 2 + (Z L -
Z _P ) ² ) ^1/2 , the micro prism is: (F1) sin (θin−90 + δ1) / sin (θin−9)
0) ≧ n and δ2 ≧ 90−δ1 + sin ⁻¹ (sin (θin−90 +
δ1) / n) or (F2) sin (θin−90 + δ1) / sin (θin−9)
0) <n and δ2 ≧ θin or (F3) sin (θin−90 + δ1) / sin (θin−9)
0) <n and θin>δ2> 90−δ1 + sin ⁻¹ (sin (θin
−90 + δ1) / n) and δ1 + δ2-sin ⁻¹ (sin (θin−90 + δ1)
/ N) + sin ^-1 (sin (θin−90 + δ2) /
n) When the condition F of -180 <0 is satisfied, the louver angle θL of the layered member is δ1−sin ⁻¹ (sin (θin−90 + δ1) / n)
−α / 2 ≦ θL ≦ δ1-sin ⁻¹ (sin (θin-9
0 + δ1) / n) + α / 2 and α / 2−θL <δ1 + 2δ2-sin ⁻¹ (sin (θi
n-90 + δ1) / n) -180. 16. The micro prism may be configured as follows: (G1) sin (θin−90 + δ1) / sin (θin−9)
0) ≧ n and δ2 ≦ θin or (G2) sin (θin−90 + δ1) / sin (θin−9)
0) <n and δ2 ≦ 90−δ1 + sin ⁻¹ (sin (θin−90 +
When the condition G of δ1) / n) is satisfied, the louver angle θL of the layered member becomes δ1−sin ⁻¹ (sin (θin−90 + δ1) / n).
−α / 2 ≦ θL ≦ δ1-sin ⁻¹ (sin (θin-9
0 + δ1) / n) + α / 2 and α / 2-θL <δ2-sin ⁻¹ (sin (90−θin
+ Δ2) / n).
5. The Fresnel lens according to item 5. 17. A substantially rectangular parallelepiped block in which transparent layers and opaque layers are alternately stacked; a support portion rigidly connected to one surface of the substantially rectangular parallelepiped block; and a support portion fixed upward with a predetermined louver angle. In the method of manufacturing a layered member in which the support portion and the substantially rectangular parallelepiped block are inclined so as to be sliced horizontally from below the substantially rectangular parallelepiped block, the support portion is made substantially the same or substantially the same hardness as the substantially rectangular parallelepiped block, and the support portion is sliced together. The manufacturing method of the layered member characterized by the above. 18. The method for manufacturing a layered member according to claim 17, wherein an auxiliary support portion having substantially the same quality or substantially the same hardness is provided on a surface of the substantially rectangular parallelepiped block to which the support portion is not connected. 19. A substantially rectangular parallelepiped block in which transparent layers and opaque layers are alternately stacked, a support portion rigidly connected to one surface of the substantially rectangular parallelepiped block, and a support portion facing upward and fixed to obtain a predetermined louver angle. A method for manufacturing a layered member in which a support portion and a substantially rectangular parallelepiped block are inclined so as to be sliced horizontally from below the substantially rectangular parallelepiped block, wherein the support portion is made divisible. 20. The method for manufacturing a layered member according to claim 19, wherein an auxiliary support portion that can be divided is provided on a surface adjacent to a surface to which the support portion of the substantially rectangular parallelepiped block is connected. 21. A method for manufacturing a layered member for slicing a block in which transparent layers and opaque layers are alternately laminated, after forming a substantially rectangular parallelepiped block in which transparent layers and opaque layers are alternately laminated, a louver in the laminating direction. A step of cutting at a plane having a size of a corner, a step of attaching a support to the cut surface, fixing the support with the support facing upward, and attaching the sliced machine so that the cut surface is horizontal, And slicing horizontally. 22. The method according to claim 17, wherein said layered member is
17. The Fresnel lens according to claim 15, wherein the Fresnel lens is manufactured by the manufacturing method according to claim 9, 20, or 21.