JPH11167805A - Reflex led element mounting multiple chips - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflex LED element mounting multiple chips which can provide flat and sufficient brightness and has improved integration density, when an infrared lighting system such as a vehicle recognition device, etc., is constituted. SOLUTION: Infrared LED elements 1, 2 are respectively loaded on the tips 3b, 6b of a first and a fourth lead frames 3, 6, further the tip 3b of the first lead frame 3 is connected to tip 5b of a third lead frame 5 by a wire 7, also the tip 6b of the fourth lead frame 6 is connected to a tip 4b of a second lead frame 4. Switching between two elements simultaneous lighting and one element lighting can be carried out by controlling constant current circuits 33a, 33b by a switching control circuit 34. Infrared ray from the two infrared LED elements 1, 2 can be efficiently radiated to the outside through a glass plate 9 having an infrared ray passing filter function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared LED device that emits light in the infrared region, which is arranged facing a concave reflector, and reflects light in the infrared region so as to have a predetermined irradiation angle. More specifically, the present invention relates to a reflective LED element mounted on a plurality of chips in consideration of an increase in integration density.

[0002]

2. Description of the Related Art Conventionally, there is a light emitting diode having a structure in which a reflection surface is provided around an element to effectively radiate light emitted from the light emitting diode element to the outside (referred to as a shell type light emitting diode). This shell-type light emitting diode has a low integration rate and a large shape, and thus is not suitable for producing a surface light source using a plurality of elements. Therefore, in order to further increase the luminous efficiency of the light emitting diode element, there has been proposed a reflection type light emitting diode which emits only reflected light to the outside without directly radiating light to the outside (Japanese Patent Laid-Open No. Hei.
0).

FIG. 5 shows a structure of a reflection type LED element. An infrared LED element 50 is fixed to an end of the lead frame 49, and wire bonding is performed between the infrared LED element 50 and the lead frame 48, and the lead frames 48, 49 are provided.
More predetermined current is supplied. A concave reflection plate 53 is arranged to face the radiation surface of the infrared LED element 50, and light in the infrared region reflected by the concave reflection plate 53 passes through the glass plate 51 having an infrared transmission filter function. Light 52 in the infrared region is emitted in the front direction (outside). In addition,
44 and 45 are dummy lead frames.

[0004]

FIG. 6 shows this reflection type LE.
The light distribution characteristics of the D element are shown. Compared to shell-type light emitting diodes, the light emission efficiency of the light in the front direction is improved, and about four times the amount of light can be emitted in the front direction, but the light amount per unit area emitted from the glass surface is Not so big. When a surface light source is configured by arranging reflective LED elements having improved luminous efficiency in a plane, it is possible to increase the amount of light emission as compared with a case where a bullet type light emitting diode element is arranged. However, since the light amount per unit area is not so large as described above, it is considered that the light emission amount of the surface light source can be further increased by increasing the integration density of the reflective LED elements.

[0005] When this is used as an infrared illuminator of a vehicle recognizing device on a road, a parking lot, or the like, the quality of capturing an image of a photographed vehicle can be further improved. SUMMARY OF THE INVENTION An object of the present invention is to provide a multiple-chip mounted reflective LED element that can provide a flat and sufficient luminance and has an improved integration density when used in an infrared illumination device such as a vehicle recognition device.

[0006]

In order to solve the above-mentioned problems, a reflective LED device mounted on a plurality of chips according to the present invention is configured such that a light emitting surface faces a concave reflector and a focal plane of the concave reflector. A plurality of infrared LED elements that emit light in the same infrared region, an infrared region light passing filter material that transmits light in the infrared region reflected at a predetermined angle by the concave reflector, And a plurality of lead frames each having the plurality of infrared LED elements mounted thereon, wherein the plurality of infrared LED elements are simultaneously driven to increase the amount of light emission. According to the present invention, in the above configuration, the plurality of infrared LEs are provided.
It has a switching unit that switches between driving only a specific element of the D element and simultaneous driving of a plurality of elements, and is configured to be able to switch between lighting of a specific element and simultaneous lighting of a plurality of elements according to ambient illuminance. It is.

Further, according to the present invention, in the above configuration, the first and second lead frames are provided from one side of the reflective LED element body, and the third and fourth lead frames are provided from the other side. 3rd lead frame and 2nd and 4th
Are arranged so as to face each other with the center of the focal plane interposed therebetween, and infrared LEDs are respectively provided at the tip of the first lead frame and the tip of the fourth lead frame.
By mounting the elements, two infrared LED elements are arranged diagonally across the center of the focal plane. Further, according to the present invention, in the above configuration, the first and second lead frames are provided from one side of the reflective LED element body, and the third and fourth lead frames are provided from the other side.
The first and third lead frames and the second and fourth lead frames are arranged so as to face each other with the center of the focal plane interposed therebetween, and are respectively provided at the tips of the first, second and third lead frames. An infrared LED element is mounted, and each infrared LED element is connected to the fourth lead frame by wire bonding. Further, according to the present invention, in the above configuration, the plurality of infrared LED elements have light emitting surfaces formed in a rectangular shape and arranged so as to be symmetrical with respect to the center of the focal plane.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a multiple-chip mounted reflective LED element according to the present invention.
(A) is a front sectional view showing an internal structure, and (b) is a bottom view showing the vicinity of a lead frame by omitting a concave reflecting surface.
The first and second lead frames 3 and 4 are of a reflective type L
Third and fourth lead frames 5 and 6 are provided from the other side from one side of the ED element body. The first and third lead frames 3 and 5 and the second and fourth lead frames 4 and 6 face each other.

The first lead frame 3 has a first end 3b
The second infrared LED element 2 is mounted on the tip 6b of the fourth lead frame 6, respectively. First infrared LED element 1 and third lead frame 5
The wire 7 is bonded between the tip 5b of the second infrared LED element 2 and the tip 4b of the second lead frame 4.
The wire 8 is bonded between them. The first and second infrared LED elements 1 and 2 are disposed on the focal plane 11a of the concave reflector 11 and on a diagonal line with the center 11b therebetween.

[0010] The infrared light emitted from the first and second infrared LED elements 1 and 2 is reflected by the concave reflection plate 11, passes through the glass plate 9 having an infrared transmission filter function, and exits to the outside. Is done. The infrared light is emitted, for example, at an irradiation angle of 8 degrees with respect to the perpendicular axis of the glass plate 9. Compared to one infrared LED element, the light amount is increased by 1.5 to 1.7 times, and the integration density is improved. End 3a of first lead frame 3
A first constant current circuit 33 a is provided between the end 4 a of the second lead frame 4 and an end 6 a of the fourth lead frame 6. The constant current circuits 33b are respectively connected. Switching control circuit 3
4 controls whether to drive only the first constant current circuit 33a or to drive the first and second constant current circuits 33a and 33b simultaneously. By setting the switching control circuit 34, only the first infrared LED element 1 can be turned on, or two infrared LED elements 1 and 2 can be turned on simultaneously.

FIG. 2 is a diagram showing another embodiment of the present invention. (A) shows the arrangement positions of the two infrared LED elements as in FIG. 1, but the infrared LEs respectively mounted on the tips of the first and fourth lead frames 15 and 18.
The D elements 13 and 14 are rectangular chips, and emit a larger amount of light than a square chip. Therefore, the reflection type LE mounted on a plurality of chips which emits a larger amount of light than that of FIG.
A D element can be obtained.

FIG. 2B shows a case where two infrared LED elements 19 and 20 are provided at the tips of first and second lead frames 15 and 16, respectively.
This is an example in which currents flow in the same direction from 5 to 17 and from 16 to 18, respectively. (C) shows three infrared LEs
D elements 21, 22, and 23 are provided at the tips of first, second, and fourth lead frames 15, 16, and 18, respectively. Further, the integration density can be increased, and the light emission amount can be increased.

FIG. 3 is a view showing an example of a surface light source constituted by a reflective LED element mounted on a plurality of chips according to the present invention. The multiple-chip mounted reflective LED element 32 of this example includes:
The lead frame is configured to protrude from the lower surface, not the side surface, of the reflective LED element body. When a plurality of reflective LED elements 32 mounted on a plurality of chips are arranged on the device substrate 31, the lead frame does not hinder the mounting, so that the reflective LED elements mounted on a plurality of chips are mounted at a high density (to the right in FIG. 3). be able to. Therefore, an infrared illuminating device having a larger light emission amount can be realized.

FIG. 4 is a moving object recognition system (vehicle recognition device) showing an example of use of the reflection type LED lighting device according to the present invention.
FIG. A device support portion 42 having a gate post 40 is provided on a road 36, and a high-definition camera 39 is provided at the center of the device support portion 42, and a reflective LED lighting device 37 having a multi-chip mounted reflective LED element according to the present invention mounted on both sides thereof. And 38 are arranged respectively. A travel time measuring terminal device 4 with a built-in high-definition image processing board is provided below the gate post 40.
1 is attached.

Under the control of the travel time measuring terminal device 41,
The high-definition camera 39 and the reflective LED lighting devices 37 and 38 are controlled, and when the vehicle 35 is detected, infrared light is emitted and the image of the vehicle 35 is captured by the high-definition camera 39. This vehicle recognition device recognizes the passing vehicle by the travel time measurement terminal device 41, and further recognizes the passing vehicle by the travel time measurement terminal device of the vehicle recognition device installed next, so that the required vehicle of the specified vehicle is recognized. Information such as time is obtained.

The reflective LED illuminator has a sharper directional characteristic edge in the range to be illuminated and a flatter light distribution characteristic in the illuminated range as compared with a strobe device.
The luminous efficiency is good, and it is characterized in that it can provide sufficient brightness (luminance) for photographing a subject surface separated by a predetermined distance. Further, it has a characteristic that irradiation can be continuously performed at an extremely short time, for example, at intervals of 1/30 to 1/15 seconds. As described above, the light distribution characteristic has a flat characteristic with respect to the strobe device. However, according to the present invention, since the reflection type LED lighting device is configured by the reflection type LED elements mounted on a plurality of chips, the light emission amount is further increased. And a good light distribution characteristic in which is increased. The high-definition camera 39 captures a still image of the vehicle 35 with image quality that allows identification of a number plate and the like. The next photographing preparation can be performed at an interval of 1/15 to 1/30 second, so that the photographing can be performed as long as the time interval is equal to or longer than the above time even if another vehicle follows.

[0017]

As described above, according to the present invention, a concave reflector and a plurality of light sources which emit light in the same infrared region are arranged near the focal point of the concave reflector so that the light emitting surfaces face each other. An infrared LED element, an infrared light transmitting filter material that transmits light in the infrared area reflected at a predetermined angle by the concave reflector, and a plurality of infrared LED elements each mounted at the tip thereof. A plurality of infrared LED elements are simultaneously driven to increase the amount of light emission. Therefore, it is possible to realize a multiple-chip mounted reflective LED element having a high integration density and an increased light emission amount. By using the multiple-chip reflective LED element according to the present invention, it is possible to obtain a flat infrared light with higher luminance without increasing the size of the surface light source, and thus a vehicle suitable for capturing high-quality images. An infrared light illumination device such as a recognition device can be obtained.

[Brief description of the drawings]

FIGS. 1A and 1B are views showing an embodiment of a reflective LED device mounted on a plurality of chips according to the present invention, wherein FIG. 1A is a front sectional view showing an internal structure, and FIG. FIG.

FIG. 2 is a diagram showing another embodiment of the present invention.

FIG. 3 is a diagram showing an example of a surface light source constituted by a reflective LED element mounted on a plurality of chips according to the present invention.

FIG. 4 is a diagram showing an example of a moving object recognition system using a reflective LED lighting device constituted by a plurality of chips mounted reflective LED elements according to the present invention.

FIG. 5 is a view showing the structure of a reflective LED element.

FIG. 6 is a diagram showing light distribution characteristics of a reflective LED element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st infrared LED element 2 ... 2nd infrared LED element 3, 15 ... 1st lead frame 4, 16 ... 2nd lead frame 5, 17 ... 3rd lead frame 6, 18 ... 2nd 4, lead frame 7, 8, 24, 25, 26, 27, 28, 29, 30 ...
Wires 9, 51: Glass plate 10, 52: Light in infrared region 11, 46: Concave reflector 13, 14, 19, 20, 21, 22, 23, 50: Infrared LED element 31: Device substrate 32: Reflective LED elements mounted on multiple chips 33a, 33b Constant current circuit 34 Switching control circuit 35 Vehicle 36 Road 37, 38 Reflective LED lighting device 39 High-definition camera 40 Gate pillar 41 Travel time measuring terminal device 42 ... Device support part 43 ... Reflective LED element 44, 45 ... Dummy lead frame 48, 49 ... Lead frame

Continued on the front page (72) Inventor Masahiko Ishii 2800 Nagachi, Okaya-shi, Nagano Kyocera Corporation President Nookaya Plant

Claims (5)

[Claims] 1. A concave reflector, and a plurality of infrared LEDs emitting light in the same infrared region, arranged so that a light emitting surface faces a focal plane of the concave reflector.
An element, an infrared region light-pass filter material that transmits light in the infrared region reflected at a predetermined angle by the concave reflector, and a plurality of lead frames each having the plurality of infrared LED elements mounted at a distal end thereof. Wherein the plurality of infrared LED elements are simultaneously driven to increase the amount of light emitted, and wherein a plurality of chips mounted reflective LED elements are provided. 2. A switching unit for switching between driving of a specific one of the plurality of infrared LED elements and simultaneous driving of a plurality of elements, wherein a specific element is turned on and a plurality of elements are switched according to ambient illuminance. 2. The multiple-chip mounted reflective LED device according to claim 1, wherein the device is configured to be able to switch between simultaneous lighting of the plurality of LEDs. 3. The first and second lead frames from one side of the reflective LED element body, the third and fourth lead frames from the other side, and the first and third lead frames and the second lead frame. And a fourth lead frame are arranged so as to face each other with the center of the focal plane interposed therebetween, and an infrared LED element is mounted on each of the tip of the first lead frame and the tip of the fourth lead frame. 2. The multiple chip mounted reflective LED element according to claim 1, wherein two infrared LED elements are arranged diagonally across the center of the focal plane. 4. The first and second lead frames from one side of the reflective LED element body, the third and fourth lead frames from the other side, and the first and third lead frames and the second lead frame. And a fourth lead frame are disposed so as to face each other with the center of the focal plane interposed therebetween. Infrared LED elements are mounted on the tips of the first, second and third lead frames, respectively, 2. The multiple chip mounted reflective LED element according to claim 1, wherein the LED element and the fourth lead frame are connected by wire bonding. 5. The plurality of infrared LED elements according to claim 1, wherein the light emitting surfaces of the plurality of infrared LED elements are formed in a rectangular shape, and are arranged symmetrically with respect to the center of the focal plane. Chip mounted reflective LED element.