JPH1065190A - Solar beam sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the output characteristics of a solar beam sensor accurately approximate the sensation hotness for a crew members. SOLUTION: In a solar beam sensor 1, the second plane 32 of a light-receiving lens 3 is composed of a conical lens 32a which blocks light rays incident from just above a light receiving lens 3, a concave lens 32b which guides oblique to horizontal light rays to a photodetecting plane 2b, and a convex lens 32c which guides oblique light rays within a prescribed range to the photodetecting plane 2b. All the lenses are optimized, whereby the output characteristics of a solar beam sensor of this constitution can be made to accurately approximate sensation of hotness for a crew member induced by sunlight incident through a window.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sunshine sensor for detecting the amount of sunlight that has arrived, and more particularly, to direct sunlight exposure to an occupant in addition to outside air temperature, such as temperature control in an air conditioner of an automobile. The present invention relates to a sunshine sensor used when it is desired to perform temperature control based on the presence or absence of a sunshine.

[0002]

2. Description of the Related Art First, a description will be given of characteristics required for a sunshine sensor used for an air conditioner of an automobile. When the sun is directly above, the occupant is shielded from direct sunlight by a roof, so that radiation (radiation) is emitted. The temperature control can be performed only by controlling the air temperature in the vehicle interior to the set temperature without being affected by heat so much.

However, in the state where the sun is inclined, the occupant receives radiant heat by being exposed to the direct sunlight entering through the window, and feels hotter than the temperature in the vehicle cabin. It is desired to appropriately lower the temperature in the vehicle compartment from the set temperature. Therefore, as the sunshine sensor, a detection characteristic proportional to the amount of radiant heat received by the occupant is desired.

An example of the configuration of a conventional sunshine sensor of this type having the above characteristics is disclosed in, for example, JP-A-2-11273.
As shown in FIG. 3 of JP-A-5, a shielding plate is provided at the center of a light-receiving lens arranged coaxially with a light-receiving element (light-receiving surface) to suppress output when the sun is directly above. .

[0005]

However, in the above-mentioned conventional sunshine sensor, since the shielding plate is provided at the center of the light receiving lens, it is certainly attenuated with respect to the sunlight from directly above, and the vehicle is not equipped with the same. Although it has a sensitivity distribution similar to that of the vehicle cabin, in practice, it is extremely difficult to approximate the heat received by the occupant with only the shielding plate.

On the other hand, by closing a part of the opening of the light receiving lens with a shielding plate, it becomes substantially equivalent to attaching a dark light receiving lens, the overall output level is reduced, and the S / N (signal / noise) is reduced. There is also a problem that the ratio is lowered and a malfunction is likely to occur, and solving these problems has been a problem.

[0007]

According to the present invention, as a specific means for solving the above-mentioned conventional problems, a light receiving lens is provided on a light receiving surface of a light receiving element so that an optical axis thereof substantially coincides with the light receiving surface. In a sunshine sensor that measures the amount of sunshine by being installed in a substantially vertical state with the light receiving lens side facing upward, the light receiving lens is configured as a substantially convex spherical surface, and a first surface arranged on the object side, a conical lens portion and a concave lens Part and a convex lens part and a second surface arranged on the light receiving element side, and the conical lens part substantially matches the center with the optical axis, and the bottom surface substantially matches the area with the light receiving surface. The light beam parallel to the optical axis is inclined so as to totally reflect the inner surface, and the tip is provided with a convex spherical surface having an appropriate radius. Concentrically The light incident on the first surface while being inclined with respect to the optical axis is refracted toward the light receiving element, and the convex lens portion is provided in a concentric shape whose inner diameter matches the outer diameter of the concave lens portion. The present invention solves the problem by providing a sunshine sensor, which is configured to refract or reflect light incident on the first surface while being inclined with respect to the optical axis toward the light receiving element. is there.

[0008]

Next, the present invention will be described in detail based on an embodiment shown in the drawings. The sunshine sensor according to the present invention is indicated by reference numeral 1 in FIG. 1, and the sunshine sensor 1 is functionally composed of a light receiving element 2 and a light receiving lens 3. Although a housing or the like for integrating the light receiving element 2 and the light receiving lens 3 is naturally provided, it is not part of the gist of the present invention, so that illustration and detailed description thereof are omitted here. .

The light receiving element 2 is, for example, a photodiode, a phototransistor or the like in which a semiconductor element having a light receiving surface 2b of a predetermined area in a case 2a is sealed by means such as a resin mold, and the light receiving lens 3 is transparent. It is formed by injection molding or casting molding of resin.

The center of the light-receiving lens 3 is positioned on a vertical line at the center of the light-receiving surface 2b, and is defined as an optical axis Z. The optical axis Z is set in a vertical state with the light-receiving lens 3 side upward, for example, a dashboard. It is installed on a car such as above, and the set temperature of the air conditioner is corrected by the output from the sunshine sensor 1,
It prevents the occupants from feeling the heat due to the radiant heat from the sunshine.

In the present invention, the light receiving lens 3 is
A first surface 31 disposed on the object side as a substantially convex spherical surface, a conical lens portion 32a, a concave lens portion 32b, and a convex lens portion 32c
And the second surface 32 disposed on the light receiving element 2 side, the detection characteristics similar to the amount of direct light received by the occupant to the sunshine sensor 1 can be obtained.

Next, the structure of the light receiving lens 3 will be described in more detail. First, the first surface 31 disposed on the object side as a convex spherical surface has an aperture which is appropriately larger than the light receiving surface 2b of the light receiving element 2. The light receiving element 2 has an area, and the light receiving element 2 can generate sensitivity to sunlight incident on the sunshine sensor 1 at a large inclination from the optical axis Z by integration with a second surface 32 described later. .

The second surface 32 has a conical lens portion 32a, a concave lens portion 32b and a convex lens portion 32, as described above.
c, the conical lens portion 32a is formed as an inverted conical shape whose center coincides with the optical axis Z, and at this time, the area of the bottom surface is made to substantially match the area of the light receiving surface 2b. .

Then, a side surface (slope) from the bottom surface to the vertex.
Is formed as an inclination angle at which light rays incident from the first surface 31 side parallel to the optical axis Z are totally reflected on the inner surface. In addition, a convex spherical surface having an appropriate radius is formed at a portion serving as a conical vertex of the conical lens portion 32a.

The concave lens portion 32b is provided concentrically with the bottom surface of the conical lens portion 32a and has the same inner diameter as that of the first lens surface. The light incident on the light receiving surface 31b is refracted in a direction approaching parallel to the optical axis Z to reach the light receiving surface 2b.

In addition, a convex lens portion 32c is provided outside the concave lens portion 32b as a concentric circle contacting the outside diameter and the inside diameter of the concave lens portion 32b. Light incident on the outer edge portion, that is, light incident on a position relatively far from the light receiving surface 2b and refracted by the first surface 31 at an angle approaching the optical axis Z is again reflected in a direction orthogonal to the optical axis Z. The light is made to reach the light receiving surface 2b by refraction.

FIGS. 2 to 5 show the state of operation of the sunshine sensor 1 of the present invention having the above-mentioned structure.
In the state where the sun is directly above and light rays are incident in parallel with the optical axis Z, the light receiving surface 2b is covered with a conical lens portion 32a having a bottom surface having almost the same area. At this time, since the conical lens portion 32a has a side surface that totally reflects the light parallel to the optical axis Z, it is not reflected and reaches the light receiving surface 2b, and only passes through the convex spherical surface provided at the apex. Only light will reach.

Therefore, in the state after noon when the direct sunlight from the sunlight is blocked by the roof, the sunshine sensor 1
Does not produce much output. Here, in practice, the occupant's perceived temperature rises even in a state where direct light is blocked by the roof due to reflection from the road surface or the like. A spherical surface is provided to obtain an appropriate output.

Then, when the sun is tilted and the occupant is slightly exposed to the light entering through the window, as shown in FIG. 3, the light reaching the side surface of the conical lens portion 32a is partially at an angle close to a right angle to the side surface. The light is transmitted without causing total internal reflection, reaches the light receiving surface 2b, and an output larger than the output by the light from the convex spherical surface described above is obtained from the sunshine sensor 1, and the correction is more strongly performed. Will be done.

When the sun is further tilted and the occupant is exposed to the light entering through the window to a moderate degree, the light from the concave lens portion 32b reaches the light receiving surface 2b as shown in FIG. Light incident on the outer edge portion of the surface 31 is also refracted by the convex lens portion 32c and reaches the light receiving surface 2b, and in the sunshine sensor 1 of the present invention, the most output is obtained at an incident angle near this.

The incident angle at this time is set, for example, as the inclination of the sun from 3:00 pm to 5:00 pm in the summer, and this is because when the temperature of the air conditioner is kept constant during this time period. This is because the occupant feels the heat of the sun most, that is, the state in which correction for solar radiation is most needed.

When the sun is further tilted and light is incident almost perpendicularly to the optical axis Z, only light from the concave lens portion 32b reaches the light receiving surface 2b as shown in FIG. , The amount of light reached also decreases, and the output of the sunshine sensor 1 decreases. That is, since this state is just before sunset and the sunshine has weakened, even if the incident light from the window reaches the occupant, the heat does not feel so much and the correction amount is small.

FIG. 6 is a graph showing the output of the sunshine sensor 1 described above. In FIG. 6, the incident angle-output curve indicated by the symbol LA indicates that the second surface 32 has the conical lens portion 32a and the concave lens portion 32b. In the figure, the incident angle-output curve indicated by reference numeral LB in the drawing indicates that the second surface 32 has a conical lens portion 32a, a concave lens portion 32b, and a convex lens portion 32c.
This shows the output when configured with.

By providing the convex lens portion 32c in this manner, the output generated by the convex lens portion 32c is added to the range of the inclination of the incident angle that requires the largest correction amount, and the sunshine sensor 1 is further improved. It is possible to have a characteristic very similar to the correction characteristic actually required. Further, each lens unit 3
By optimizing 2a to 32c, it is possible to further approximate the correction characteristics.

FIG. 7 shows another embodiment of the present invention. In the above-described convex lens portion 32c due to refraction, it may not be possible to form the convex lens portion 32c depending on conditions such as a required incident angle. At this time, the illustrated convex lens portion 3
The light transmitted through the first surface 31 as shown in 2d may be reflected by internal reflection to allow the light to reach the light receiving surface 2b.

Although the above description has been made with reference to the movement of the sun from noon to sunset, FIGS. 5 to 2 naturally show from sunrise to noon. Moreover, although the above explanation was described at the time of cooling, it can also be used at the time of heating,
In that case, when the output of the sunshine sensor 1 is large, the control is performed in a direction to lower the room temperature.

[0027]

As described above, according to the present invention, a conical lens portion that blocks light from directly above and transmits light obliquely to the second surface of the light receiving lens, and receives light from oblique to horizontal on the second surface of the light receiving lens. A sunshine sensor composed of a concave lens part that guides the surface and a convex lens part that guides the oblique light in a predetermined range to the light receiving surface. By optimizing each lens part, the sunlight that the occupant enters from the window And the output characteristics of the sunshine sensor are accurately approximated, thereby improving the performance of this type of sunshine sensor, and thus exhibiting an extremely excellent effect in improving the performance of the vehicle air conditioner. Things.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a sunshine sensor according to the present invention.

FIG. 2 is an explanatory diagram showing a state of receiving light from directly above the sunshine sensor with respect to sunlight.

FIG. 3 is an explanatory diagram showing a state of receiving light from the sunshine sensor with respect to tilted sunlight.

FIG. 4 is an explanatory diagram showing a state of receiving light from the sunshine sensor with respect to further inclined sunlight.

FIG. 5 is an explanatory diagram showing a state in which the sunshine sensor receives light from horizontal sunlight.

FIG. 6 is a graph showing an incident angle-output curve of the same sunshine sensor.

FIG. 7 is an explanatory view showing another embodiment of the sunshine sensor according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Sunshine sensor 2 ... Light receiving element 2a ... Case 2b ... Light receiving surface 3 ... Light receiving lens 31 ... First surface 32 ... Second surface 32a ... Conical lens part 32b ... Concave lens part 32c, 32d … Convex lens part Z …… Optical axis LA, LB …… Incident angle-output curve

Claims (1)

[Claims] 1. A sunshine sensor for measuring a sunshine amount by installing a light receiving lens on a light receiving surface of a light receiving element with an optical axis substantially coincident with the light axis and installing the optical axis in a substantially vertical state with the light receiving lens side upward. The light receiving lens is configured as a substantially convex spherical surface and disposed on the object side, and includes a second surface disposed on the light receiving element side configured of a conical lens portion, a concave lens portion, and a convex lens portion, The conical lens portion has a center substantially coincident with the optical axis, a bottom surface substantially coincident with the light receiving surface, and a slanted surface is inclined such that light rays parallel to the optical axis are totally reflected on the inner surface. Is provided with an inverted conical configuration, and the concave lens portion is provided in a concentric shape having an inner diameter coinciding with the bottom surface of the conical lens portion, and inclines light with respect to the optical axis to enter the first surface. Refracted toward the light receiving element The convex lens portion is provided in a concentric shape having an inner diameter coinciding with an outer diameter of the concave lens portion, and refracts or reflects light incident on the first surface inclined with respect to the optical axis toward the light receiving element. A sunshine sensor, characterized in that the sunshine sensor is configured to: