JPH077184A - Semiconductor light emitting element, projector, optical detector and information processor employing it - Google Patents

Abstract

PURPOSE:To provide a semiconductor light emitting element having high emission output and a function for controlling the direction of emission. CONSTITUTION:A plate 6 is loaded onto the surface of light emitting element chip 1 having an active layer 2 on the emission side thereof. The plate 6 is provided with a conical or truncated pyramid type opening 7 and bonded to the chip 1 on the smaller opening side. A metal film is deposited entirely on the inner peripheral face at the conical opening 7 thus forming a reflective layer 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device. In particular, it relates to a semiconductor light emitting element in which the emission direction of light is controlled. The present invention also relates to a light projector, an optical detection device, and an optical information processing device using the light emitting element.

[0002]

BACKGROUND ART AND ITS PROBLEMS FIG. 17 is a cross-sectional view showing a conventional semiconductor light emitting device Q in which the emission direction of light is controlled (JP-A-4-10479). This semiconductor light emitting device Q is
The active layer 82 is provided in the central portion on the lower surface side of the substrate 81.
A light emitting window 83 is provided on the upper surface side of the light emitting window 83 so as to face the active layer 82, and the peripheral portion of the light emitting window 83 (the outer peripheral surface of the substrate 81) is curved so as to be convexly bent toward the inner surface side of the substrate 81. Has been made. Then, inside the convex slope 84 formed around the light exit window 83, a reflective layer 85 is formed by impurity diffusion.
Are formed. Reference numeral 86 is an upper surface electrode, and 87 is a lower surface electrode.

However, as shown in FIG. 17, the active layer 82
The light α emitted from is reflected by the reflective layer 85 toward the light emission window 83 and emitted from the light emission window 83 to the outside of the element. Therefore, according to the light emitting element Q having such a structure, the light α is generated by the reflective layer 85 formed on the convex slope 84.
It is possible to control the outgoing direction of the light and improve the optical coupling efficiency with external parts such as lenses and optical fibers.

In such a conventional semiconductor light emitting device Q, the light α reflected by the reflecting layer 85 near the light emitting window 83 is emitted to the outside from the light emitting window 83. However, since the reflection layer 85 is narrowed so that the diameter becomes smaller in the light emission direction, the light α reflected by the reflection layer 85 in a region away from the light emission window 83 is directed in a direction different from that of the light emission window 83. Since it was reflected, the optical coupling efficiency could not be improved as originally intended. In addition, the outer peripheral surface of the substrate 1 has an inverted trumpet-shaped convex slope 8 by etching.
4 has to be formed, there is a drawback that the process for that is complicated and the manufacturing cost is increased.

By the way, applications of this kind of semiconductor light emitting device include an optical detection device such as a distance sensor and a photoelectric sensor, and a light projector which is a light source portion thereof. Conventionally, a semiconductor laser element (LD) or a light emitting diode (LED) has been used for this kind of light source portion. this house,
The semiconductor laser device is a device suitable for an optical detection device such as a photoelectric sensor because it can generate a beam with high output and directivity. However, the semiconductor laser device is vulnerable to noise and temperature fluctuations, which makes the drive circuit expensive and dangerous to the human body (especially the eyes), so that the application range is limited.

On the other hand, the light-emitting diode is strong against disturbances such as temperature fluctuations and noise, but has no Lambertian type directivity and has low optical coupling efficiency with external parts such as lenses and optical fibers. . Therefore, when used in an optical detection device such as a distance sensor, there is a problem that the detection distance is short. Further, since the light emitting diode generally has a lower light emission output than the semiconductor laser device, there is a problem that the detection distance is further shortened. As a result, particularly in a light emitting diode, it is desired to control the emission direction of light to enhance directivity and obtain a high light emission output.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above background art, and an object of the present invention is to have a function of controlling a light emitting direction and a high light emission output. Another object is to provide a semiconductor light emitting device having Further, it is an object of the present invention to provide an optical detection device having a long detection distance capability, a high performance and simple structure of the projector by using such a semiconductor light emitting element.

[0008]

A semiconductor light emitting device of the present invention comprises a light emitting device chip having an active layer for emitting light in a plane direction, and a plate loaded on the light emitting side surface of the light emitting device chip. The plate is characterized in that a substantially tapered opening is penetrated through the plate so that the opening diameter becomes smaller on the side facing the light emitting element chip, and a reflective layer is formed on the inner peripheral surface of the opening.

In the semiconductor light emitting device, the opening is provided so as to face the light emitting window formed in the light emitting device chip, and the area of the light emitting window is the side where the opening diameter of the opening is small. The opening area may be smaller than the opening area.

Further, a current constriction structure may be formed inside the light emitting element chip so as to correspond to the light emission window formed in the light emitting element chip.

Further, the bottom area of the plate may be larger than the area of the light emitting element chip.

Further, a plurality of grooves may be formed in a region of the plate other than the region where the opening is formed.

Further, at least the surface of the plate may be conductive.

Further, the plate may be made of silicon.

Further, the shape of the opening may be a substantially circular taper shape, and a spherical lens may be mounted inside or on the upper side of the opening.

Further, a recess for fixing a lens may be formed inside or above the opening of the plate, and a lens such as a hemispherical lens or a Fresnel lens may be mounted in the recess.

Further, the opening of the plate may be sealed with a transparent resin material, and the transparent resin material may have a lens function.

In the projector of the present invention, the semiconductor light emitting element is mounted on a lead frame, the semiconductor light emitting element is sealed and molded in a predetermined shape with a transparent resin material, and a flat lens is formed on the surface of the transparent resin material. It is characterized by being integrally molded.

The optical detecting device of the present invention is characterized by including the above semiconductor light emitting element.

An optical information processing apparatus of the present invention is characterized by including the above semiconductor light emitting element.

[0021]

In the semiconductor light emitting device of the present invention, the plate loaded on the light emitting device chip has a substantially tapered opening penetrating therethrough, and a reflection layer is formed on the inner peripheral surface of the opening. The emitted beam emitted from the light emitting element chip is reflected by the reflection layer of the plate in a direction close to the optical axis, and the beam emitted to the outside after being reflected by the reflection layer can be narrowed, The efficiency of optical coupling with external parts such as or optical fiber is increased.

In particular, by combining a so-called point light source type light emitting element chip in which the original light emitting region is miniaturized with the plate, only the beam emitting direction can be changed without changing the light output that can be extracted to the outside. As a result, an excellent light source with high directivity can be obtained.

[0023]

1 is a schematic sectional view showing the structure of a semiconductor light emitting device A according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a light emitting element chip, inside of which a surface emitting type active layer 2 which emits light in a surface direction is formed. Since the internal structure of the light emitting element chip 1 is not particularly limited, only the active layer 2 and the upper and lower electrodes 3, 4 are shown in the drawing. A relatively large light emitting window 5 (that is, an opening portion of the upper surface electrode 3) is formed on the upper surface of the light emitting element chip 1, and a plate 6 is loaded on the light emitting window 5 on the upper surface of the light emitting element chip 1. There is. The plate 6 is provided with a conical or pyramidal opening 7 having a small opening diameter on the one hand and a large opening diameter on the other hand, such as a conical shape or a pyramid shape. 7 is bonded to the upper surface of the light emitting element chip 1 on the side with the smaller opening diameter. A reflective layer 8 is formed on the entire inner peripheral surface of the conical opening 7 by depositing a metal film, for example. If the plate 6 is made of a material having a high thermal conductivity,
Since the plate 6 works as a heat sink, the temperature characteristic becomes good.

FIG. 2 is a diagram illustrating the behavior of light rays emitted from the active layer 2 of the semiconductor light emitting device A. Of the light emitted from the active layer 2, the light α0 emitted vertically upward from the point P0 directly below the conical opening 7 is as it is.
The light is emitted to the outside substantially parallel to the optical axis X through. Also,
For example, the light emitted from the point P1 or P2 of the active layer 2 travels in all directions of 360 ° vertically and horizontally. Of these, the light emitted upward from the active layer 2 like the light rays α1 or α2 in FIG. 2 is reflected by the reflective layer 8 in a direction substantially parallel to the optical axis X. As a result, the light emitted from the conical opening 7 has a limited emission direction and is emitted to the outside as a beam with a small spread. Therefore, when an external component such as a lens or an optical fiber is arranged so as to face the conical opening 7 of the plate 6, the beam emitted from the conical opening 7 and the lens, the optical fiber, etc. The optical coupling efficiency of is improved.

FIG. 3 is a schematic sectional view showing the structure of a semiconductor light emitting device B according to the second embodiment of the present invention. In this embodiment, when the light emitting window 5 is formed by partially opening the upper surface electrode 3 on the upper surface of the light emitting element chip 1, the opening diameter of the cone-shaped opening 7 is smaller than the minimum value. The light exit window 5 is opened. The plate 6 is arranged so that the light exit window 5 of the light emitting element chip 1 is included in the lower surface opening of the conical opening 7. Also in this embodiment, it is possible to make the directions of the light uniform and narrow the spread of the beam by the same operation as in the first embodiment. Moreover, the light emitting element chip 1
Since the area of the light emission window 5 is smaller than the bottom cross-sectional area of the conical opening 7 of the plate 6, all the light emitted from the light emission window 5 is guided to the conical opening 7. The outgoing beam can be strengthened without reducing the original optical output, and the effect of improving the optical coupling efficiency is great.

FIG. 4 is a schematic sectional view showing the structure of a semiconductor light emitting device C according to the third embodiment of the present invention. The light emitting element chip 1 has a current constriction structure, and a current blocking region 9 is formed below the upper surface electrode 3. The current blocking region 9 is formed by, for example, injecting protons or the like to increase the resistance of the injected portion. In the light emitting device chip 1 having such a current constriction structure, when a voltage is applied between the upper and lower electrodes 3 and 4, the current flows only in the current passage region 10 below the light emission window 5, so that the active layer 2 Emits light only in a minute area facing the light exit window 5.

In the case of the light emitting element chip 1 having the current confinement structure like the semiconductor light emitting element C, an originally narrow outgoing beam can be obtained by the current confinement structure. However, when a plate 6 having a conical or pyramidal reflection layer 8 is loaded on the light-emitting element chip 1 having the current constriction structure, the spread beam is reflected by the reflection layer 8 and emitted. Is bent in a direction substantially parallel to the optical axis X, the light beam can be further narrowed to increase the light output, and the optical coupling efficiency with external parts such as lenses and optical fibers is further improved. Moreover, since the light can be extracted to the outside more efficiently, a high-power and narrow light beam can be obtained.

In each of the above embodiments, only one conical opening 7 is provided in the plate 6, but a plurality of conical openings 7 may be provided in an array (also in the following embodiments. The same). By providing the conical openings 7 in an array, it is possible to fabricate a semiconductor light emitting device in which light emitting portions are newly arrayed without changing the structure of the light emitting device chip. At this time, a light emitting element array in which the emitted beam is narrowed can be obtained by forming the light emitting element as a point light source type light emitting element array and combining it with a plate having a conical opening corresponding to the emitting portion of each element. .

FIG. 5 is a schematic sectional view showing the structure of a semiconductor light emitting device D according to the fourth embodiment of the present invention. In this embodiment, the bottom area of the plate 6 is made larger than the area of the light emitting element chip 1, and the outer peripheral portion 6a of the plate 6 is projected beyond the outer peripheral surface of the light emitting element chip 1. As a result, of the light emitted from the active layer 2, the light emitted to the side surface of the light emitting element chip 1 (so-called leakage light) can be blocked by the outer peripheral portion 6a of the plate 6 and prevented from being emitted in the beam emission direction. As a result, when the semiconductor light emitting device D is used in a projector of an optical detection device such as a photoelectric switch, it is effective in reducing noise light. Further, the plate 6 is made of a conductive material such as metal, or the surface of a non-conductive material such as ceramic is coated with a conductive material such as metal. If the and are conducted, the current can be injected into the light emitting element chip 1 from above the plate 6, and the mountability is improved.

FIG. 6 is a schematic sectional view showing the structure of a semiconductor light emitting device E according to the fifth embodiment of the present invention. In this embodiment, a groove is formed on the upper surface of the plate 6 in a region other than the region where the conical opening 7 is provided, and a plurality of groove portions 11 are formed.
Has a structure. According to this structure,
Since the heat dissipation area of the plate 6 is increased, the heat dissipation of the light emitting element chip 1 can be effectively performed through the plate 6. It is preferable that the plate 6 is made of a material having a high thermal conductivity and a thermal expansion coefficient substantially equal to that of the light emitting element chip 1. However, considering the ease of groove processing and the process compatibility with the light emitting element chip 1, Silicon is preferred.

FIG. 7 is a schematic sectional view showing the structure of a semiconductor light emitting device F according to the sixth embodiment of the present invention. In this embodiment, a spherical lens 12 is attached to the cone-shaped conical opening 7 of the plate 6, and the emitted light is made parallel by the spherical lens 12. In this embodiment, by changing the mounting position of the spherical lens 12 depending on the application, the emitted light can be diffused, condensed, or collimated.

FIG. 8 is a schematic sectional view showing the structure of a semiconductor light emitting device G according to the seventh embodiment of the present invention. In this embodiment, the recess 1 is formed around the conical opening 7 of the plate 6.
3 is formed, and the hemispherical lens 14 is attached to the upper surface of the conical opening 7 so that the periphery is fitted into the concave portion 13. Although not shown, a flat Fresnel lens may be used instead of the hemispherical lens 14. Also in this embodiment, the hemispherical lens 14 (or the flat Fresnel lens)
Thus, the emitted light can be collimated, diffused or condensed. In the present embodiment, if the recess 13 on the upper surface of the plate 6 is processed with an appropriate allowance for the hemispherical lens 14 or Fresnel lens, the hemispherical lens 14 and Fresnel lens can be moved within the recess 13. Therefore, these lenses can be fixed to the plate 6 with an adhesive or the like in a state where the optical axes thereof are aligned with each other, and the emitted light beam can be controlled more precisely.

FIG. 9 is a schematic sectional view showing the structure of a semiconductor light emitting device H according to the eighth embodiment of the present invention. In this embodiment, a resin material 15 transparent to the light emitted from the light emitting element chip 1 is filled in the conical opening 7 of the plate 6. In general, the transparent resin material 15 has a refractive index n larger than that of air (refractive index = 1), so that the conical opening 7
By filling the inside with the transparent resin material 15, the reflection critical angle at the light exit window 5 of the light emitting element chip 1 becomes large. Therefore, the amount of light that can be extracted to the outside is increased, so that it is possible to obtain a semiconductor light emitting device H of higher output. The shape 15a of the transparent resin material 15 on the light emitting side
7 and FIG.
Similarly to the semiconductor light emitting devices F and G, the emitted light can be collimated, condensed, or diffused.

Next, application examples using the above semiconductor light emitting device will be described. First, FIG. 10 (a) (b) (c)
The projector J shown in FIG. This floodlight J includes a semiconductor light emitting device 21 of the present invention, one of which is a lead frame 22.
While die-bonding on the above and wire-bonding to the other lead frame 23, the resin is low-pressure cast into a predetermined shape with a sealing resin 24 such as a transparent epoxy resin and sealed.
The overall shape is a square block. On the surface of the sealing resin 24, a Fresnel type flat plate lens 25 in which a large number of annular lens units are concentrically arranged is integrally formed, and at the same height as the Fresnel type flat plate lens 25 or Fresnel on both sides of the surface. A jaw portion 26 that is slightly higher than the die flat plate lens 25 is provided so as to project, and the jaw portion 26 protects the Fresnel flat plate lens 25.

In the case of this projector J, the semiconductor light emitting element 21
Has a narrow emission direction of light and has a high luminous efficiency, so that the optical coupling efficiency to the Fresnel-type flat plate lens 25 is improved, the output is strong, and a thin beam can be obtained even at a long distance. To be

As a conventional projector R, there is one having a structure as shown in FIG. This is a can-seal type in which a semiconductor laser element 93 and a Fresnel type flat lens 94 are attached to a heat sink 92 protruding from the stem 91, and these are covered with a metal cap 95. In comparison, the projector J of the present invention has a greatly simplified structure,
The cost and bulk volume can be reduced.

Although the projection light beam that emits parallel light rays having a narrow directivity has been described here, by changing the parameters of the Fresnel type flat plate lens 25, it can be used as a projection light beam for a focused beam or a deflected beam. The applicability is self-evident.

FIG. 11 shows a semiconductor light emitting device 31 according to the present invention.
It is explanatory drawing which shows the structure of the optical distance sensor K using. The distance sensor K is composed of a light projecting portion including a semiconductor light emitting element 31 and a collimating lens 32 according to the present invention, and a light receiving portion including a light receiving lens 33 and a position detecting element 34.

Further, FIG. 11 shows a case where the unevenness step d of the object 35 is measured by the distance sensor K. The light emitted from the semiconductor light emitting element 31 is collimated by the collimator lens 32, and then is irradiated onto the object 35 to generate beam spots SP ₁ and SP _{2, which} are reflected by the beam spots SP ₁ and SP ₂ , respectively. An image is formed on the position detecting element 34. These image forming positions can be detected by the signal ratio obtained by the signal lines 36 and 37 of the position detecting element 34, and the step d is calculated from the amount of positional deviation using the principle of triangulation.

Since the semiconductor light emitting device 31 according to the present invention has a high output and a minute light emitting window in which the emission emission direction is limited, the semiconductor light emitting device 31 according to the present invention is used for such a distance sensor K. Thus, long-distance detection is possible, the beam spot diameter is small, and the resolution can be improved.

FIG. 12 shows the measurement result of the step d by the distance sensor K. This is 10c from the distance sensor K
2 mm and 5 mm in height and 2 at a position separated by m
It is a measurement result when an object having concave portions of mm and 5 mm is positioned, and a characteristic curve 38 corresponding to the step d is obtained. In the characteristic curve 38, a is a 2 mm convex portion, b is a 5 mm convex portion, c is a 5 mm concave portion, and d is 2 mm.
It is a portion corresponding to the concave portion of.

FIG. 13 shows a semiconductor light emitting device 41 according to the present invention.
It is a schematic sectional drawing which shows the coupling unit L which couple | bonded with the optical fiber 42. In this coupling unit L, the conical opening 7 of the semiconductor light emitting element 41 and the end face of the optical fiber 42 are opposed to each other with a certain distance. In such a coupling unit L, the light coupling efficiency strongly depends on the light emitting direction and the light emitting diameter of the semiconductor light emitting element 41. The narrower the light emitting emitting direction is, and the smaller the light emitting diameter is, the higher the light coupling efficiency is. It is known to rise. Since the semiconductor light emitting device 41 of the present invention is a device having a small light emission diameter and the emitted light is narrowed, it is possible to obtain high optical coupling efficiency in the coupling unit L. In particular, the semiconductor light emitting device 41 according to the present invention can suppress the heat generation of the device due to the miniaturization of the light emitting diameter, so that it is possible to construct a system with low loss and high SN ratio in an optical fiber communication system. become.

FIG. 14 shows a semiconductor light emitting device 51 according to the present invention.
It is a schematic diagram showing an optical fiber type sensor M using. This optical fiber type sensor M includes a semiconductor light emitting element 51, a light projecting optical fiber 52, a light receiving optical fiber 53, and a light receiving element 5.
4 and a processing circuit 55. The light emitted from the semiconductor light emitting element 51 is sent in the light projecting optical fiber 52 with low loss, and emitted from the end face of the optical fiber 52 toward the object 56. The light reflected by the object 56 enters the light receiving optical fiber 53 and is received by the light receiving element 54 as a signal. In this way, the output of the light receiving signal detected by the light receiving element 54 is output from the end faces of the light projecting and receiving optical fibers 52 and 53 and the object
Since it changes depending on the distance S with respect to 6, the distance S from the light reception output to the object 56 can be known. Moreover, since the received light output increases in accordance with the incident light output, by using the semiconductor light emitting device 51 of the present invention, a sufficient received light signal can be obtained even if the distance to the object 56 is long.

FIG. 15A is a perspective view showing a transmissive optical rotary encoder N using the semiconductor light emitting device 65 according to the present invention. The rotary encoder N includes a rotary plate 62 attached to the rotary shaft 61, a fixed plate 63 facing the outer peripheral portion of the rotary plate 62, and a projection lens 64 facing the rotary plate 62 and the fixed plate 63. It comprises a semiconductor light emitting device 65 and a light receiving device 66 according to the invention. The outer circumference of the rotary plate 62 is perforated with slits 67 at intervals of 1 mm, and the fixed plate 63 is also perforated with track A slits 68 and track B slits 69 at intervals of 1 mm.

The light emitted from the semiconductor light emitting element 65 is collimated by the light projecting lens 64, divided by the slits 68 and 69 of the fixed plate 63, passes through the slit 67 of the rotary plate 62, and passes through the light receiving element. It is detected at 66. The track A slit 68 and the track B slit 69 of the fixed plate 63 are shifted in electrical phase angle by 90 °.
The scale is read by counting when both phase signals are turned on (light receiving state) as one unit (one slit) of the scale. Further, as shown in FIG. 15B, the rotation direction can be determined depending on whether the A phase is turned on or the B phase is turned on.

In this rotary encoder, for example, a conventional surface-emitting type semiconductor light emitting device (emission diameter 400 μm) is used.
m) and collimating with a projection lens having a focal length f = 10 mm and a lens diameter of 4 mm, the beam diameter on the rotating plate spreads to the slit width of the fixed plate + about 40 μm due to the poor collimating property. Light output is low. Therefore, with a scale of 600 DPI (40 μm pitch) or more, the beam spreads beyond the slit width, the scale cannot be read, and high resolution cannot be achieved.

On the other hand, in the rotary encoder N using the semiconductor light emitting device 65 according to the present invention, the emitted beam is narrowed and the conical opening 7 of the plate 6 is used.
The emission diameter of the semiconductor light emitting device 65 can be made 10 μm or less by making the opening diameter of the device smaller. Therefore, even if the same lens is used for collimation, the beam diameter on the rotating plate 62 can be suppressed to the slit width of the fixed plate + about 0.5 μm,
It is possible to increase the resolution and read a scale of 600 DPI (40 μm pitch) or more.

Further, the semiconductor light-emitting device 65 of the present invention in which the plate 6 having the array-shaped conical openings 7 is provided and the light-emitting portions are arranged in an array is used, and a lens for collimation is provided in each conical opening 7. If attached, the light source portion can be downsized. Therefore, it is possible to realize a small rotary encoder N with high resolution.

Although the rotary encoder has been described in the above embodiment, the same effect can be obtained by using the semiconductor light emitting device according to the present invention in the linear encoder.

FIG. 16A is an example of an optical information processing apparatus and is a perspective view showing a bar code reader P using a semiconductor light emitting device 71 according to the present invention. This bar code reader P includes a semiconductor light emitting element 71 and a light projecting side condenser lens 7.
2, a rotary polygon mirror 73, a scanner motor 74 for rotating the rotary polygon mirror 73 in a constant direction at a constant speed, a constant velocity scanning lens 75, a light receiving side condensing lens 76, and a light receiving element 77.

Thus, the light emitted from the semiconductor light emitting element 71 passes through the light projecting side condenser lens 72, and the rotating polygon mirror 73.
The light beam is reflected by the laser beam, is scanned in the horizontal direction, is made uniform in velocity by the constant velocity scanning lens 75, is condensed on the barcode 78, and is scanned on the barcode 78. Further, the reflected light from the bar code 78 is condensed and detected on the light receiving element 77 by the light receiving side condensing lens 76, and the bar code signal BS is obtained. In this barcode reader P,
Since the scanning speed of the light beam is made uniform by the uniform speed scanning lens 75, when the horizontal axis represents time and the vertical axis represents the detection signal (bar code signal BS), as shown in FIG. 16 (b). A signal BS corresponding to the bar code 78 is obtained.

In such a bar code reader,
A semiconductor laser element is generally used as a semiconductor light emitting element, but a bar code reader using a light emitting diode is desired because of the danger of the semiconductor laser element to the human body. However, the light emitting diode has a wide light emitting and emitting direction as described above, low optical coupling efficiency to the light projecting side condenser lens 72, and generally has a light emitting region of about 400 μm. The beam diameter on the code becomes larger than 6.7 mm, and the bar code (generally, the minimum line width is 0.2 mm) cannot be read at all.

On the other hand, in the semiconductor light emitting device 71 according to the present invention, by making the opening diameter of the conical opening 7 formed in the plate 6 small, a small light emitting device can be obtained. Therefore, even if light is collected under the same conditions, the barcode 7
The beam diameter on 8 can be narrowed down to the minimum line width of the barcode 78 (less than 0.2 mm), and the barcode 78
Can be read. As described above, by using the semiconductor light emitting device of the present invention, it is possible to realize a light emitting diode which has excellent temperature characteristics and is strong against surges.

[0054]

According to the semiconductor light emitting device of the present invention, since the outgoing beam emitted from the light emitting device chip can be reflected by the reflecting layer in the direction close to the optical axis, it is reflected by the reflecting layer. The beam emitted to the outside can be narrowed, and the efficiency of optical coupling with external parts such as lenses and optical fibers is increased.

In particular, if a so-called point light source type light emitting element chip such as a light emitting element chip having a small light emitting window or a light confining structure light emitting element chip is combined with the plate, the light output that can be extracted to the outside can be changed. Since it is possible to change only the emission direction of the beam without having to do so, an excellent light source with high directivity can be obtained.

Further, when the bottom area of the plate is larger than the area of the light emitting element chip, so-called leakage light emitted from the side surface of the light emitting element chip can be blocked, which is effective in reducing the noise of the upper emission light.

Further, when the plate is processed with a plurality of grooves, the heat radiation area of the plate becomes large, so that the heat radiation of the light emitting element chip can be effectively performed through the plate.

In particular, when a plate made of silicon is used, the plate has good thermal conductivity, the plate functions as a heat sink, and the coefficient of thermal expansion is almost the same as that of the light emitting element chip, so that a semiconductor light emitting element having excellent temperature characteristics is manufactured. be able to. Furthermore, using a silicon plate,
Process compatibility with the light emitting device chip is also obtained.

Furthermore, when a plate having conductivity on at least the surface is used, current can be injected into the light emitting element chip from above the plate, so that the semiconductor light emitting element can be easily mounted and the manufacturing cost is reduced.

Further, by mounting various lenses such as a spherical lens, a hemispherical lens, and a Fresnel lens in the opening of the plate, it is possible to obtain an outgoing beam according to the application such as condensed light, parallel light or diffused light. it can.

Further, when the semiconductor light emitting device of the present invention is used for a projector of an optical detection device such as a photoelectric switch, a photo interrupter, or an optical distance meter, a light beam with a small emission beam and a large emission output can be obtained. It is possible to obtain an optical detection device which is excellent in detection accuracy and safe without using a complicated optical system. Similarly, when the semiconductor light emitting device of the present invention is used as a light source for fiber communication, the efficiency of optical coupling to the optical fiber is improved, so that an optical communication device having a long transmission distance can be obtained. Furthermore, when the semiconductor light emitting device of the present invention is used in an optical information processing device, an optical information processing device having excellent temperature characteristics can be created.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a structure of a semiconductor light emitting device according to a first embodiment of the present invention.

FIG. 2 is a ray diagram showing a behavior of light in the above embodiment.

FIG. 3 is a schematic sectional view showing a structure of a semiconductor light emitting device according to a second embodiment of the present invention.

FIG. 4 is a schematic sectional view showing the structure of a semiconductor light emitting device according to a third embodiment of the present invention.

FIG. 5 is a schematic sectional view showing a structure of a semiconductor light emitting device according to a fourth embodiment of the present invention.

FIG. 6 is a schematic sectional view showing a structure of a semiconductor light emitting device according to a fifth embodiment of the present invention.

FIG. 7 is a schematic sectional view showing the structure of a semiconductor light emitting device according to a sixth embodiment of the present invention.

FIG. 8 is a schematic sectional view showing the structure of a semiconductor light emitting device according to a seventh embodiment of the present invention.

FIG. 9 is a schematic sectional view showing the structure of a semiconductor light emitting device according to an eighth embodiment of the present invention.

10 (a), (b) and (c) are a perspective view, a horizontal sectional view and a side sectional view showing a projector using the semiconductor light emitting device according to the present invention.

FIG. 11 is a schematic view showing a configuration of a distance sensor using a semiconductor light emitting device according to the present invention.

FIG. 12 is a diagram showing an example of a measurement result obtained by the above distance sensor.

FIG. 13 is a sectional view showing a coupling unit of a semiconductor light emitting device and an optical fiber according to the present invention.

FIG. 14 is a schematic view showing a configuration of an optical fiber type sensor using a semiconductor light emitting device according to the present invention.

15A is a perspective view showing a rotary encoder using a semiconductor light emitting device according to the present invention, and FIG. 15B is a waveform diagram showing an A phase signal and a B phase signal of the encoder.

16A is a perspective view showing a bar code reader using a semiconductor light emitting device according to the present invention, and FIG. 16B is a view showing a detection signal by the bar code reader.

FIG. 17 is a sectional view showing a structure of a conventional semiconductor light emitting device.

FIG. 18 is a partially cutaway perspective view showing a conventional light projector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light emitting element chip 2 Active layer 5 Light emission window 6 Plate 7 Conical opening 8 Reflective layer 11 Groove 12 Spherical lens 14 Hemispherical lens

Claims (13)

[Claims] 1. A light emitting element chip having an active layer that emits light in a plane direction, and a plate loaded on the surface of the light emitting element chip on the light emitting side, the opening being on the side facing the light emitting element chip. A semiconductor light emitting device characterized in that a substantially tapered opening is penetrated through the plate so as to have a small diameter, and a reflective layer is formed on an inner peripheral surface of the opening. 2. The opening is provided so as to face a light exit window formed in the light emitting element chip, and the area of the light exit window is smaller than the opening area on the side where the opening diameter of the opening is small. The semiconductor light emitting device according to claim 1, which is characterized in that. 3. The semiconductor light emitting device according to claim 1, wherein a current confinement structure is formed inside the light emitting device chip so as to correspond to a light emission window formed in the light emitting device chip. 4. The area of the bottom of the plate is larger than the area of the light emitting device chip.
Alternatively, the semiconductor light emitting device according to the item 3. 5. The semiconductor light emitting device according to claim 1, wherein a plurality of grooves are processed in a region of the plate other than the region where the opening is formed. 6. The plate according to claim 1, 2, 3, 4, or 5, wherein at least a surface of the plate has conductivity.
The semiconductor light-emitting device according to. 7. The semiconductor light emitting device according to claim 1, 2, 3, 4, 5, or 6, wherein the plate is made of silicon. 8. The shape of the opening is a substantially circular taper shape, and a spherical lens is attached to the inside or the upper part of the opening, 1, 2, 3, 4, 5, 6 or 7. The semiconductor light-emitting device according to. 9. A recess for fixing a lens is formed inside or above an opening of the plate, and a lens such as a hemispherical lens or a Fresnel lens is mounted in the recess. The semiconductor light emitting device according to 3, 4, 5, 6 or 7. 10. An opening of the plate is sealed with a transparent resin material, and the transparent resin material has a lens function. The semiconductor light-emitting device according to. 11. The method according to claim 1, 2, 3, 4, 5, 6 or 7.
The semiconductor light emitting device according to claim 1 is mounted on a lead frame, the semiconductor light emitting device is sealed and molded in a predetermined shape with a transparent resin material, and a flat lens is integrally molded on the surface of the transparent resin material. . 12. The method according to claim 1, 2, 3, 4, 5, 6, 7,
An optical detection device comprising the semiconductor light emitting device described in 8, 9, or 10. 13. The method according to claim 1, 2, 3, 4, 5, 6, 7,
An optical information processing apparatus comprising the semiconductor light emitting device described in 8, 9, or 10.