Light-receiving device and laser marking system

Abstract

To provide a light receiving device capable of improving the response characteristics of a light receiving element while suppressing an increase in the device scale. A light receiving device that receives laser light emitted from a light emitting device, comprising: a substrate; at least one or more light receiving elements provided on the substrate and each consisting of a phototransistor having a light receiving surface on an upper surface; a light emitting element provided at a position spaced apart from the light receiving element on the substrate and having a light emitting surface on an upper surface; a light-transmissive dielectric formed so as to cover the light receiving element and the light emitting element; and a light diffusion reflection transmission unit provided at any position except above the light receiving element on the light-transmissive dielectric, for diffusing, reflecting, and transmitting light.

Description

Technical Field

[0001] The present invention relates to a light receiving device, and more particularly to a light receiving device that receives laser light in position detection using a laser alignment device.

Background Art

[0002] In work sites such as construction and civil engineering, a laser alignment device is used to check the parallelism and perpendicularity in surveying. In the measurement using a laser alignment device, laser light is emitted from the laser alignment device, and the parallelism and perpendicularity of the irradiation position are confirmed based on the visual observation or the reception result by a laser receiver.

[0003] Conventionally, for a laser receiver that receives laser light irradiated from a laser alignment device, in order to carry it together with many tools in work such as construction and civil engineering, further weight reduction and miniaturization have been demanded. In the laser receiver, a large-area photodiode has been used as a light receiving element. The photodiode has good response characteristics and can detect laser light even in a dark place. On the other hand, since a large area is required, not only does the device scale of the entire laser receiver become large, but the cost also becomes high. In order to make the light receiving area smaller, a phototransistor having good sensitivity per unit area may be used instead of the photodiode. However, the phototransistor has poor response characteristics and cannot detect laser light in a dark place. Even if laser light can be visually recognized in a dark place, if the laser receiver cannot detect it, it may be regarded as a malfunction of the laser receiver. As a method for improving the response characteristics of the phototransistor, there is a method of irradiating bias light (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In order to achieve both reducing the light-receiving area to miniaturize the device and the response characteristics, it is necessary to use a phototransistor as the light-receiving element and provide an illumination mechanism for irradiating bias light as in the above-described conventional technology. However, there has been a problem that the device size of the laser light receiver increases due to the provision of the illumination mechanism.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a light-receiving device mounted on a laser light receiver capable of improving the response characteristics of the light-receiving element while suppressing cost reduction and an increase in the device size.

Means for Solving the Problems

[0007] The light-receiving device according to the present invention is a light-receiving device that receives laser light emitted from a light-emitting device, and includes a substrate, at least one or more light-receiving elements each including a phototransistor provided on the substrate and having a light-receiving surface on an upper surface thereof, a light-emitting element provided at a position spaced apart from the light-receiving element on the substrate and having a light-emitting surface on an upper surface thereof, a light-transmissive dielectric formed so as to cover the light-receiving element and the light-emitting element, and a light diffusion reflection transmission portion provided at any position on the light-transmissive dielectric except above the light-receiving element, for diffusing light and reflecting and transmitting the light.

[0008] Further, the light-receiving device according to the present invention is a light-receiving device that receives laser light emitted from a light-emitting device, and includes a substrate, a light-receiving element including a phototransistor provided on the substrate and having at least one or more light-receiving surfaces on an upper surface thereof, a light-emitting element provided at a position spaced apart from the light-receiving element on the substrate and having a light-emitting surface on an upper surface thereof, and a light diffusion reflection transmission portion formed at any position in an area above the substrate except above the light-receiving surface, for diffusing light and reflecting and transmitting the light.

[0009] Further, the light receiving device according to the present invention is a light receiving device that receives laser light emitted from a light emitting device, and includes a substrate, a light receiving element provided on the substrate and composed of a phototransistor having a light receiving surface on an upper surface, a light emitting element provided on the substrate and having a light emitting surface on an upper surface, a light diffusion reflection and transmission portion provided above the light emitting element for diffusing, reflecting, and transmitting light, the light receiving element having a first light receiving surface and a second light receiving surface adjacent to each other with a boundary line therebetween, and the light emitting element being provided with at least one or more on an extension of the boundary line.

[0010] Further, the laser marking system according to the present invention includes a light emitting device that emits laser light, a substrate, at least one or more light receiving elements provided on the substrate and composed of a phototransistor having a light receiving surface on an upper surface, a light emitting element provided at a position separated from the light receiving element on the substrate and having a light emitting surface on an upper surface, and a light-transmissive dielectric formed so as to cover the light receiving element and the light emitting element.

Effects of the Invention

[0011] According to the present invention, it is possible to improve the response characteristics of the light receiving element while suppressing an increase in the device scale.

Brief Description of the Drawings

[0012]

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Figure 6C

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Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following descriptions of the respective embodiments and in the attached drawings, the same reference numerals are given to substantially the same or equivalent parts.

Embodiment

[0014] FIG. 1 is a diagram showing the configuration of a laser alignment system 100 according to Embodiment 1 of the present invention. The laser alignment system 100 is composed of a laser alignment device 200 and a light receiver 300.

[0015] The laser alignment device 200 is a light emitting device that emits laser light serving as a reference line for construction such as "horizontal" and "right angle" on walls, ceilings, and floors. By indicating vertical lines, horizontal lines, etc. with laser light, it is used for positioning the installation locations of steel frames and reinforcing bars, and for positioning the attachment locations of fixtures, electrical outlets, etc. In this embodiment, the laser alignment device 200 irradiates a line light LT extending in the horizontal direction toward the wall surface WL of the building.

[0016] The light receiver 300 is a laser light receiver that receives the laser light emitted from the laser alignment device 200. The light receiver 300 has a function of detecting the position of the laser light emitted by the laser alignment device 200 and notifying the detection result by means of light, sound, notification to the laser alignment device 200, etc.

[0017] In this embodiment, the light receiver 300 is used to detect the irradiation position when the line light LT irradiating the wall surface WL of the building is moved up, down, left, and right. The light receiver 300 has a light receiving element including two light receiving surfaces, and the two light receiving surfaces are arranged so as to be adjacent to each other in the height direction of the wall surface WL. Then, by comparing the amount of laser light received by each of the light receiving surfaces, the center position of the line width of the line light LT is detected.

[0018] FIG. 2 is a top view of the light receiving device 400 according to Embodiment 1 of the present invention. The light receiving device 400 is an electronic component that receives laser light and converts it into an electrical signal, and is mounted on the light receiver 300 in FIG. 1. The light receiving device 400 is used as a laser light receiving device that receives laser light emitted from a laser marking device (not shown) in positioning using a laser marking device. The surface of the light receiving device 400 is irradiated with the laser light emitted from a laser marking device (not shown) in a line shape.

[0019] The light receiving device 400 includes a substrate 11, a light receiving element 12 having two light receiving surfaces provided adjacent to each other on the substrate 11, a resin bank 13 formed on the substrate 11 so as to surround the periphery of the light receiving element 12, a light emitting element 14 provided in the vicinity of the light receiving element 12, and a light transmissive dielectric 15 provided so as to fill the region surrounded by the resin bank 13. In this embodiment, the light receiving device 400 has a substantially rectangular shape in a top view, with the x direction shown in FIG. 2 being the short side direction and the y direction being the long side direction.

[0020] The substrate 11 is composed of a printed circuit board made of a glass epoxy substrate, a polyimide substrate, or the like. On one surface of the substrate 11 that is the element mounting surface (hereinafter, also simply referred to as the substrate surface), the light receiving element 12, the resin bank 13, the light emitting element 14, etc. are mounted.

[0021] The light-receiving element 12 is composed of a phototransistor. The phototransistor is composed of a combination of a photodiode and a transistor (amplification circuit), and has a sensitivity per unit area that is several tens to several hundreds of times that of a normal photodiode. In this embodiment, the light-receiving element 12 is configured by arranging a pair of phototransistors having a shape extending in one direction (the y direction in the figure) in a vertical row in the extending direction in a top view. The light-receiving element 12 is arranged so as to have a light-receiving surface on the upper surface, that is, so that the light-receiving surface faces upward in the normal direction of the substrate surface (that is, in the direction opposite to the vertical direction when the substrate 11 is placed horizontally).

[0022] The resin bank 13 is a frame portion that protrudes from the surface of the substrate 11 and surrounds the periphery of the light-receiving element 12 while being spaced apart on the substrate 11. In this embodiment, the resin bank 13 is composed of a silicone resin and has an annular shape surrounding the periphery of the light-receiving element 12 in a top view. The region surrounded by the resin bank 13 on the substrate 11 is filled with a light-transmissive dielectric (not shown in FIG. 2).

[0023] The light-emitting element 14 is a bias light source provided for irradiating the light-receiving element 12 with bias light. The light-emitting element 14 is composed of, for example, a light-emitting diode (LED). The light-emitting element 14 is arranged so that the upper surface is a light-emitting surface, that is, so that the light-emitting surface faces upward in the normal direction of the light-receiving surface of the light-receiving element 12 and the substrate surface.

[0024] The surface of the light-receiving device 400 is irradiated with laser light emitted from a laser marking device (not shown) in a line shape.

[0025] FIG. 3 is a diagram showing an enlarged view of the region A1 surrounded by the broken line in FIG. 2.

[0026] The light-emitting element 14 has a rectangular shape in a top view. On the surface of the translucent dielectric at a position above the light-emitting element 14, a light diffusion reflection transmission portion 16 is formed. The light diffusion reflection transmission portion 16 has the property of scattering the bias light emitted from the light-emitting element 14, that is, the property of diffusing, reflecting, and transmitting incident light. In this embodiment, the light diffusion reflection transmission portion 16 is composed of a satin finish surface having a random uneven surface shape. Note that the light diffusion reflection transmission portion 16 is not limited to a surface having such a random uneven surface shape, and the surface may be flat but may be composed of a light diffusion transmission film in which scattering particles are dispersed inside.

[0027] The satin finish surface constituting the light diffusion reflection transmission portion 16 is formed so as to cover a wider range than the upper surface of the light-emitting element 14 in a top view. In this embodiment, the satin finish surface has a region wider by a width “h” than the upper surface of the light-emitting element 14.

[0028] In this embodiment, the surface of the light-receiving device 400 is irradiated with laser light emitted from a laser marker (not shown). The laser light emitted from the laser marker has a line shape extending along a direction (x direction in the figure) orthogonal to the extending direction of the light-receiving element 12.

[0029] FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3.

[0030] On the substrate 11, a light-receiving element 12 and a light-emitting element 14 are provided, and a resin bank 13 is formed at a height “h” so as to surround the periphery thereof. Note that the light-receiving element 12 and the light-emitting element 14 are each connected to the substrate 11 by wire bonding, but illustration thereof is omitted here.

[0031] In the region surrounded by the resin bank 13, a translucent dielectric 15 is formed so as to fill the light-receiving element 12 and the light-emitting element 14. The translucent dielectric 15 is composed of, for example, a resin such as glass or a transmissive epoxy or silicone.

[0032] On the surface of the light-transmitting dielectric 15, a light-diffusing reflection and transmission portion 16 is formed. The light-diffusing reflection and transmission portion 16 is formed, for example, by adding a filler to the surface of the light-transmitting dielectric 15. Specifically, the light-diffusing reflection and transmission portion 16 is formed by applying a resin containing light-scattering particles as a filler to the surface of the light-transmitting dielectric 15.

[0033] The light-scattering particles constituting the filler are composed of, for example, titania, silica, alumina, zinc oxide, magnesium oxide, glass, etc., and have a particle diameter of 0.25 μm to several μm. By appropriately selecting the material and size of the light-scattering particles, the optical surface roughness of the matte surface constituting the light-diffusing reflection and transmission portion 16 can be controlled.

[0034] Note that, differently, a matte surface may be formed by physically roughening the surface of the light-transmitting dielectric 15. For example, a matte surface may be formed by performing blasting on the surface of the light-transmitting dielectric 15 to form irregularities. At that time, the irregularities formed are preferably both in depth and width in the range of sub-μm to several μm. Also, in addition to blasting, a matte surface may be formed by forming irregularities by other surface treatments such as engraving or laser processing.

[0035] Also, the light-diffusing reflection and transmission portion 16 may be a plastic light-diffusing film in which inorganic fine particles (several μm or less) such as titanium oxide and zirconia or organic fine particles (1 μm to a dozen or so μm) of acrylic or silicone type or both inorganic and organic fine particles are dispersed in a film such as polyethylene terephthalate (PET), polycarbonate resin, or acrylic. The plastic light-diffusing film may be attached to the light-transmitting dielectric 15 with a light-transmitting adhesive such as an acrylic-based adhesive, a silicone rubber-based adhesive, and a synthetic rubber-based adhesive.

[0036] Next, a method for manufacturing the light-receiving device 400 of this embodiment will be described. FIG. 5 is a flowchart showing the flow of the manufacturing method. FIGS. 6A to 6D and FIGS. 7A to 7C are cross-sectional views of the device at each step of the flowchart of FIG. 5.

[0037] First, as shown in FIG. 6A, a printed circuit board made of a glass epoxy board, a polyimide board, or the like is prepared (STEP101). The printed circuit board has a state in which substrate regions corresponding to a plurality of light receiving devices are arranged in a matrix, and in a wafer dicing process described later, by performing a singulation process, each substrate region (substrate 11) corresponding to each light receiving device is cut out.

[0038] Next, as shown in FIG. 6B, a light emitting element 14 is mounted on the surface of the substrate 11 by die bonding (STEP102).

[0039] Next, a conductive adhesive 17 is applied at a position separated by a predetermined distance from the light emitting element 14 on the substrate 11, and the light receiving element 12 is fixed by die bonding (STEP103). As a result, as shown in FIG. 6C, a device in which the light emitting element 14 and the light receiving element 12 are mounted on the substrate 11 is formed.

[0040] Next, as shown in FIG. 6D, the light emitting element 14, the light receiving element 12, and the substrate 11 are connected by wire bonding (shown as WB in the figure) (STEP104). For example, each emitter electrode of a pair of phototransistors constituting the light receiving element 12 and a pad portion of an emitter terminal of a printed circuit board constituting the substrate 11 are electrically connected by wire bonding using a metal wire (such as gold or silver).

[0041] Next, on the surface of the substrate 11, a silicone resin is formed so as to surround the periphery of the phototransistor constituting the light receiving element 12. For example, using a dispenser, a highly viscous light-blocking silicone resin (for example, a room temperature curable silicone resin having a viscosity of about 85 Pa·s) is applied so as to surround the periphery of the light receiving element 12. As a result, a resin bank 13 is formed as shown in FIG. 7A (STEP105).

[0042] Next, a light-transmissive silicone resin with a relatively low viscosity (for example, a viscosity of 1.3 to 1.7 Pa·s) is filled into the region surrounded by the resin bank 13 using a dispenser. As a result, as shown in FIG. 7B, a light-transmissive dielectric 15 is formed so as to cover the region surrounded by the resin bank 13 (STEP106).

[0043] Next, a resin containing light-scattering particles is applied to a position above the light-emitting element 14 (near directly above) on the surface of the light-transmissive dielectric 15. As a result, as shown in FIG. 7C, a light-diffusing reflection-transmission portion 16 is formed (STEP107).

[0044] The printed circuit board that has undergone the above process is cut for each substrate region corresponding to an individual light-receiving device, and the light-receiving device is separated into individual pieces (STEP108).

[0045] Through the steps as described above, the light-receiving device 400 of this embodiment is manufactured.

[0046] The light-receiving device 400 has a light-emitting element 14 that emits bias light. The light-receiving element 12 receives the laser light irradiated to the light-receiving device 400 and also receives the bias light emitted from the light-emitting element 14. Thereby, the response characteristics of the light-receiving element 12 can be improved.

[0047] The light-emitting element 14 is arranged such that it has a light-emitting surface on its upper surface, that is, the light-emitting surface is in the upward direction of the normal to the substrate surface, similar to the light-receiving surface of the light-receiving element 12. Therefore, for example, compared with the case where the light-emitting element is arranged such that the light-emitting surface of the light-emitting element and the light-receiving surface of the light-receiving element face each other, the size of the light-receiving device in the height direction can be suppressed.

[0048] Also, since the light-diffusing reflection-transmission portion 16 is formed above the light-emitting surface of the light-emitting element 14, the bias light emitted from the light-emitting element 14 is scattered in the light-diffusing reflection-transmission portion 16. Thereby, the component of the bias light incident on the light-receiving element 12 can be increased compared with the case where there is no light-diffusing reflection-transmission portion 16.

[0049] In addition, the linear laser light emitted from the laser printer is irradiated not only to the light receiving element 12 but also to the light emitting element 14 and its related members. The irradiated laser light is reflected by the light emitting element 14 and its related members and then enters the light receiving element 12. At this time, in the light receiving device 400 of the present embodiment, since the light diffusion reflection transmission portion 16 is provided above the light emitting element 14, the laser light reflected by the light emitting element 14 and its related members is scattered by the light diffusion reflection transmission portion 16. As a result, the component of the laser light reflected by the light emitting element 14 and its related members that enters the light receiving element 12 is reduced.

[0050] Note that the refractive index of the glass or resin constituting the translucent dielectric 15 is preferably about 1.4 to 1.6. Also, as described above, the light diffusion reflection transmission portion 16 covers a region that is wider by a width "h" (i.e., about the same as the height of the resin bank 13) than the upper surface of the light emitting element 14 in a top view. For this reason, the critical angle is about 45 degrees, and it is possible to prevent the laser light from reaching the light emitting element 14.

Embodiment

[0051] FIG. 8 is a top view of a light receiving device 500 according to Embodiment 2 of the present invention. The light receiving device 400 is different from the light receiving device 400 of Embodiment 1 in that a ceramic frame 21 is formed on the surface of the substrate 11 instead of the resin bank, and a light diffusion reflection transmission portion is formed on a band-pass filter provided on the ceramic frame 21.

[0052] The ceramic frame 21 is a frame portion that protrudes from the surface of the substrate 11 and surrounds the periphery of the light receiving element 12 on the substrate 11 at a distance. The ceramic frame 21 is made of a black ceramic and is adhered to the surface of the substrate 11 using an adhesive or the like. The ceramic frame 21 has an annular shape that surrounds the periphery of the light receiving element 12 in a top view.

[0053] FIG. 9 is an enlarged view showing the region A2 surrounded by the broken line in FIG. 8.

[0054] The light diffusion reflection and transmission portion 16A is formed on a band-pass filter (not shown) provided on the ceramic frame 21. The frosted surface constituting the light diffusion reflection and transmission portion 16A is formed, similarly to the frosted surface of the first embodiment, so as to cover a wider range than the upper surface of the light-emitting element 14 in a top view, and has a region wider by a width "h" than the upper surface of the light-emitting element 14.

[0055] FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. 9.

[0056] A light-receiving element 12 and a light-emitting element 14 are provided on the substrate 11, and a ceramic frame 21 is formed at a height "h" so as to surround the periphery thereof.

[0057] Above the region surrounded by the ceramic frame 21 of the substrate 11, a band-pass filter 22 is formed so as to straddle the ceramic frame 21. The band-pass filter 22 has the property of allowing the laser light emitted from the laser marking device to pass through and blocking light in other bands (particularly, the bias light emitted from the light-emitting element 14). Thereby, the laser light from the laser marking device can be distinguished from light such as sunlight and indoor illumination light. In this embodiment, the band-pass filter 22 is composed of an optical band filter made of glass or acrylic that transmits green laser light. The band-pass filter 22 is adhered to the ceramic frame 21 with an adhesive.

[0058] On the band-pass filter 22, a light diffusion reflection and transmission portion 16A made of a frosted surface is formed. The frosted surface is formed by performing surface processing such as blasting on the surface of the band-pass filter 22 made of, for example, glass or acrylic (the surface corresponding to the position above the light-emitting element 14). The frosted surface is formed to have a surface roughness of 0.25 μm to several μm.

[0059] In contrast, the light diffusion reflection and transmission part 16A may be made of a film such as polyethylene terephthalate (PET), polycarbonate resin, or acrylic, which contains inorganic fine particles (several μm or less) such as titanium oxide and zirconia, or organic fine particles (1 μm to a dozen or so μm) such as acrylic-based or silicone-based particles. Further, for example, it may be composed of a plastic light diffusion film in which both inorganic fine particles and organic fine particles are dispersed. In that case, the light diffusion reflection and transmission part 16A is formed by attaching a plastic light diffusion film to the surface of the band-pass filter 22 with a light-transmissive adhesive such as an acrylic-based adhesive, a silicone rubber-based adhesive, or a synthetic rubber-based adhesive.

[0060] Next, a method for manufacturing the light receiving device 500 of the present embodiment will be described. FIG. 11 is a flowchart showing the flow of the manufacturing method. FIGS. 12A and 12B are cross-sectional views of the device in some steps of the flowchart of FIG. 11.

[0061] Since STEP201 to 204 are the same as STEP101 to 104 of the first embodiment, the description thereof will be omitted here.

[0062] The light emitting element 14 and the light receiving element 12 are mounted on the surface of the substrate 11 and electrically connected by wire bonding. Then, a ceramic frame 21 made of a black ceramic is adhered to the surface of the substrate 11 using an adhesive. Thereby, as shown in FIG. 12A, a ceramic frame 21 is formed so as to surround the periphery of the light receiving element 12 (STEP205).

[0063] Next, an optical band-pass filter having a light diffusion reflection and transmission part 16A with a matte surface formed by blasting is adhered to the upper surface of the ceramic frame 21 using an adhesive so as to cover the area surrounded by the ceramic frame 21. Thereby, as shown in FIG. 12B, the band-pass filter 22 is mounted (STEP206).

[0064] The printed circuit board that has undergone the above process is cut into substrate regions corresponding to individual light-receiving devices, and the light-receiving devices are separated into individual pieces (STEP207).

[0065] Through the above steps, the light-receiving device 500 of this embodiment is manufactured.

[0066] The light-receiving device 500 of this embodiment includes a light-emitting element 14 having a light-emitting surface on the upper surface, similar to the light-receiving device 400 of Embodiment 1. Above the light-emitting surface of the light-emitting element 14, a band-pass filter 22 is provided. The band-pass filter 22 has the property of allowing the laser light emitted from the laser marking device to pass through and blocking the bias light emitted from the light-emitting element 14. Therefore, the bias light emitted from the light-emitting element 14 is incident on the light-receiving element 12. Thus, according to the light-receiving device 500 of this embodiment, while suppressing the size of the light-receiving device in the height direction, the response characteristics of the light-receiving element 12 can be improved.

[0067] Also, similar to Embodiment 1, a light diffusion reflection transmission portion 16A is formed above the light-emitting surface of the light-emitting element 14, and since the bias light emitted from the light-emitting element 14 is scattered in the light diffusion reflection transmission portion 16A, the component of the bias light incident on the light-receiving element 12 can be increased compared to the case where there is no light diffusion reflection transmission portion 16A.

Embodiment

[0068] FIG. 14 is a top view of a laser light receiver 600 according to Embodiment 3 of the present invention. Here, the illustration of the housing is omitted. A light-receiving module in which a light-receiving element 12 is provided on the surface of a substrate 11 is provided on the surface of a light-receiving circuit board 18. The light-receiving element 12 is composed of a phototransistor. In this embodiment, the light-receiving element 12 is configured by arranging a pair of phototransistors having a shape extending in one direction (the y direction in the figure) in a vertical row in the extending direction in a top view. The light-receiving element 12 is arranged such that it has a light-receiving surface on the upper surface, that is, the light-receiving surface is in the upward direction of the normal to the substrate surface (i.e., the direction opposite to the vertical direction when the substrate 11 is horizontally placed on the light-receiving circuit board 18).

[0069] The light emitting element 14 is formed on the surface of the light receiver circuit board 18 and is disposed on the extension line of the boundary line of the pair of photo transistors constituting the light receiving element 12. Above the light emitting element 14, a light diffusion reflection transmission part 16 is provided.

[0070] FIG. 15 is a cross-sectional view taken along the line a-a of FIG. 14. A box-shaped light receiver housing 19 is provided so as to surround the light receiver circuit board 18, the light emitting element 14, and the light receiving module including the substrate 11 and the light receiving element 12. An opening is provided in the ceiling portion of the light receiver housing 19 at a position above the light receiving module, and a band-pass filter 22 is disposed in the opening so as to cover the upper part of the light receiving element 12. The band-pass filter 22 has the property of allowing the laser light emitted from the laser marking device to pass through and blocking light in other bands (particularly, the bias light emitted from the light emitting element 14). In this embodiment, the band-pass filter 22 is composed of an optical band filter made of glass or acrylic that transmits green laser light. The band-pass filter 22 is adhered to the light receiver housing 19 with an adhesive.

[0071] The light diffusion reflection transmission part 16 is disposed at a position above the light emitting element 14 in the ceiling portion of the light receiver housing 19. In this embodiment, the light diffusion reflection transmission part 16 has a bullet-shaped cap shape. The light diffusion reflection transmission part 16 may be composed of an inorganic fine particle (several μm or less) such as titanium oxide or zirconia or an organic fine particle (1 μm to a dozen or so μm) such as an acrylic-based or silicone-based fine particle on a film such as polyethylene terephthalate (PET), polycarbonate resin, or acrylic. Further, for example, it may be composed of a plastic light diffusion film in which both inorganic fine particles and organic fine particles are dispersed. In that case, the light diffusion reflection transmission part 16 is formed by attaching, to the light receiver housing 19, a plastic light diffusion film with a light-transmissive adhesive such as an acrylic-based adhesive, a silicone rubber-based adhesive, or a synthetic rubber-based adhesive.

[0072] FIG. 16 is a block diagram showing the internal configuration of the laser light receiver 600 formed inside the housing CA.

[0073] As shown in FIG. 16, the laser light receiver 600 includes photoelectric conversion elements 31 and 32, a selector 33, a band-pass filter (BPF) 34, a logarithmic conversion circuit 35, an analog-to-digital converter (ADC) 36, a controller 37, a sound generation circuit 38, a speaker 39, a lighting drive circuit 40, and light-emitting elements Lr, Ly, Lg, and Lp.

[0074] The photoelectric conversion element 31 converts the light received by the light-receiving surface into an electrical signal indicating the intensity of the light, and supplies this as a first received light signal d1 to the selector 33. The photoelectric conversion element 32 converts the light received by the light-receiving surface into an electrical signal indicating the intensity of the light, and supplies this as a second received light signal d2 to the selector 33.

[0075] The selector 33 alternately selects one of the first received light signal d1 and the second received light signal d2 at a predetermined period according to the selection signal SE supplied from the controller 37, and outputs this to the band-pass filter 34.

[0076] The band-pass filter 34 extracts a signal component in a predetermined frequency band from the first received light signal d1 or the second received light signal d2 supplied from the selector 33, and supplies a received light signal df composed of the extracted signal component to the logarithmic conversion circuit 35.

[0077] The logarithmic conversion circuit 35 performs a logarithmic conversion process on the received light signal df, and supplies the signal obtained thereby as a received light intensity signal dlg representing the received light intensity to the analog-to-digital converter 36.

[0078] The analog-to-digital converter 36 supplies a received light intensity data signal DT obtained by converting the value indicated by the received light intensity signal dlg into a digital value to the controller 37.

[0079] The controller 37 includes a ROM (Read Only Memory) 371 in which a laser irradiation position determination program is stored, and a RAM (Random Access Memory) 372.

[0080] The controller 37 supplies a selection signal SE to the selector 33 and captures the received light intensity data signal DT in accordance with the laser irradiation position determination program stored in the ROM 371.

[0081] Also, the controller 37 generates a buzzer sound signal BS for instructing no buzzer sound or a buzzer sound signal BS for instructing the output of a buzzer sound and designating the pitch (e.g., the pitch of "do") of the buzzer sound in accordance with the laser irradiation position determination program, and supplies this to the sound generation circuit 38.

[0082] Furthermore, the controller 37 generates a lighting control signal LS for instructing the lighting of one of the light emitting elements Lr, Ly, and Lg or a lighting control signal LS for instructing to turn off all of the light emitting elements Lr, Ly, and Lg in accordance with the laser irradiation position determination program, and supplies this to the lighting drive circuit 40.

[0083] When the sound generation circuit 38 receives a buzzer sound signal BS for instructing the output of a buzzer sound, it generates a sound signal having the waveform of the buzzer sound of the pitch specified by the buzzer sound signal BS and supplies this to the speaker 39. Thereby, the speaker 39 outputs a buzzer sound based on this sound signal to the outside through the sound hole. Also, when the sound generation circuit 38 receives a buzzer sound signal BS indicating no buzzer sound, it supplies a sound signal representing silence to the speaker 39. Thereby, the speaker 39 is in a silent state where no sound is output.

[0084] When the lighting drive circuit 40 receives a lighting control signal LS instructing to light one of the light emitting elements Lr, Ly, and Lg, it supplies a lighting drive signal to the light emitting elements Lr, Ly, and Lg to light that one and turn off the other two. Thereby, when the light emitting element Lr is instructed to light, the light emitting element Lr emits red light, and both the light emitting elements Ly and Lg are turned off. Also, when the light emitting element Ly is instructed to light, the light emitting element Ly emits yellow light, and both the light emitting elements Lr and Lg are turned off. Further, when the light emitting element Lg is instructed to light, the light emitting element Lg emits green light, and both the light emitting elements Lr and Ly are turned off.

[0085] Also, when the lighting drive circuit 40 receives a lighting control signal LS instructing to turn off all of the light emitting elements Lr, Ly, and Lg, it supplies a lighting drive signal to the light emitting elements Lr, Ly, and Lg to turn off all of them. Thereby, all of the light emitting elements Lr, Ly, and Lg are turned off.

[0086] Also, when the power button of the laser receiver is pressed, the lighting drive circuit 40 receives a lighting control signal LS instructing to light the light emitting element Lp and lights the light emitting element Lp. When the power button is pressed again, the lighting drive circuit 40 receives a lighting control signal LS instructing to turn off the light emitting element Lp and turns off the light emitting element Lp.

[0087] Note that the embodiments of the present invention are not limited to those described in the above examples. For example, in the above Example 1, the case of forming the translucent dielectric 15 by filling the region surrounded by the resin bank 13 with the translucent silicone resin was described. However, the shape of the translucent dielectric is not limited to this.

[0088] For example, as shown in FIG. 13, a plate-shaped translucent dielectric 15A (i.e., a translucent plate) made of a resin such as glass, epoxy-silicon, etc. may be disposed on the resin bank 13 so as to cover the upper part of the region surrounded by the resin bank 13 of the substrate 11. Also in a light-receiving device having such a configuration, it is possible to form a frosted surface as the light diffusion reflection transmission portion 16 by subjecting the translucent dielectric 15A to physical surface treatment.

[0089] In addition, in the above-described second embodiment, the configuration in which the band-pass filter 22 is provided above the region surrounded by the ceramic frame 21 of the substrate 11 (i.e., the configuration of FIG. 10) has been described. However, the same translucent dielectric as in the first embodiment may be filled up to the height below the ceramic frame 21 in the region, and the band-pass filter 22 may be disposed on the upper surface of the translucent dielectric.

[0090] In contrast, the light diffusion reflection transmission portion may be a plastic light diffusion film in which inorganic fine particles (several μm or less) such as titanium oxide and zirconia or organic fine particles (1 μm to a dozen or so μm) of an acrylic or silicone type or both inorganic and organic fine particles are dispersed in a film such as polyethylene terephthalate (PET), polycarbonate resin, or acrylic. The plastic light diffusion film may be attached to the surface of the band-pass filter 22 with a light-transmissive adhesive such as an acrylic-based adhesive, a silicone rubber-based adhesive, and a synthetic rubber-based adhesive.

[0091] In the above-described first and second embodiments, the case where the light diffusion reflection transmission portion 16 (16A) is formed above the light-emitting element 14 has been described as an example. However, the formation position of the light diffusion reflection transmission portion 16 (16A) is not limited to this, and it may be provided at any position in the area above the substrate 11 except above the light-receiving element 12.

[0092] FIG. 17A is a cross-sectional view showing a light-receiving device according to a modified example in which a light diffusion reflection and transmission portion 16 is disposed at a position not directly above the light-emitting element 14. A band-pass filter 22 is provided so as to cover the upper side of the light-emitting element 14 and the light-receiving module including the substrate 11 and the light-receiving element 12. The light diffusion reflection and transmission portion 16 is provided at a portion of the inner surface of the band-pass filter 22 (i.e., the surface facing the substrate 11) that is located between the upper side of the light-emitting element 14 and the upper side of the light-receiving element 12.

[0093] For example, when the light-emitting element 14 is composed of an LED (Laser Emitting Diode) chip, the light emitted from the LED generally spreads without directivity. Therefore, the bias light emitted from the light-emitting element 14 spreads and is radiated in the direction indicated by the arrow in the figure. For this reason, the light diffusion reflection and transmission portion 16 may be disposed at a position where the emitted light can reach, and may be disposed at a position deviated from directly above the light-emitting element 14 as shown in FIG. 17A. By disposing the light diffusion reflection and transmission portion 16 at such a position, the bias light can be made incident on the light-receiving surface of the light-receiving element without increasing the thickness direction (height direction) of the light-receiving device. For example, when the light-emitting element 14 has the light distribution characteristics of a general LED chip, the relative illuminance is high in the angular range of about 30° to 60° with respect to the normal direction of the emission surface. Therefore, by disposing the light diffusion reflection and transmission portion 16 in the vicinity, a large amount of light can reach the light-receiving element 12.

[0094] FIG. 17B is a cross-sectional view showing a light-receiving device according to a modified example in which a light diffusion reflection and transmission portion 16 is disposed at a position not directly above the light-emitting element 14 in a configuration in which a box-shaped light-receiving device housing 19 is provided so as to surround the light-receiving module. The band-pass filter 22 is provided on the ceiling portion of the light-receiving device housing 19 including the upper side of the light-receiving element 12. An opening is provided in the ceiling portion of the light-receiving device housing 19 at a position above the light-emitting element 14. The light diffusion reflection and transmission portion 16 is provided at a position between the opening in the ceiling portion of the light-receiving device housing 19 and the band-pass filter 22.

[0095] Placing the light diffusion reflection and transmission section 16 at a position offset from directly above the light emitting element 14 in this way is also useful from the perspective of preventing stray light of the laser light. That is, according to such a configuration, when laser light incident from outside the light receiving device (for example, a laser light emitting device) irradiates the light emitting element 14, it is possible to prevent the scattered light, that is, the stray light, from entering the light receiving element 12.

[0096] Note that the position of the light diffusion reflection and transmission section 16 may be extended from the position shown in FIG. 17A to the area directly above the light emitting element 14. As described above, the light diffusion reflection and transmission section 16 may be provided in an area above the substrate 11 excluding the area above the light receiving element 12.

[0097] Also, the manufacturing method of the light receiving device is not limited to that described in the above embodiments. For example, in the first embodiment, after connecting the light emitting element 14 and the light receiving element 12 by wire bonding in STEP104, the resin bank 13 is formed in STEP105, and the light transmissive dielectric 15 is formed by filling the area surrounded by the resin bank 13 with a light transmissive silicone resin in STEP106. However, differently from this, after STEP101 to 104, the light transmissive dielectric 15 may be formed by applying a light transmissive epoxy resin to the front surface of the substrate and curing it.

[0098] Also, the contents described in the above embodiments can be used in appropriate combinations. For example, in the first embodiment described above, the case where the frame portion surrounding the light receiving element 12 is composed of the resin bank 13 and the case where the frame portion is composed of the ceramic frame 21 in the second embodiment are respectively described. However, for example, in the first embodiment, a ceramic frame similar to that in the second embodiment may be used instead of the resin bank 13.

[0099] Also, in the third embodiment, the case where the light diffusion reflection and transmission section 16 is composed of a film is described as an example, but the light diffusion reflection and transmission section 16 may be composed of a plastic light diffusion plate or a plastic light diffusion cap.

[0100] Also, by adjusting the distribution of the fine particles used in the light diffusion reflection and transmission section 16 according to the amount of light emitted from the light-emitting element, the visibility of the power lamp and the phototransistor response performance of the bias light can be adjusted. For example, when the amount of light incident on the light-receiving element 12 as the bias light is large, the amount of fine particles may be reduced or the particle size may be decreased. When it is desired to suppress the amount of light of the power lamp and increase the amount of bias light, for example, the distribution of inorganic fine particles may be increased.

[0101] In addition, in the third embodiment, the case where the light-emitting element 14 is provided on the surface of the light-receiving circuit board 18 has been described as an example. However, the position of the light-emitting element 14 is not limited to this. For example, as shown in FIG. 18, the light-emitting element 14 may be provided on the surface of the substrate 11. In that case, the light diffusion reflection and transmission section 16 located above the light-emitting element 14 is arranged at a position closer to the band-pass filter 22 than in FIG. 15.

[0102] In addition, in the third embodiment, as shown in FIG. 15, the case where the light diffusion reflection and transmission section 16 has a bullet-shaped cap shape and is provided so as to cover the upper part of the light-emitting element 14 while being separated from the light-emitting element 14 has been described as an example. However, the position and shape of the light diffusion reflection and transmission section 16 are not limited to this. For example, as shown in FIG. 19A, the light diffusion reflection and transmission section 16 having a bullet-shaped shape may be adhered to the light-emitting element 14 and provided so as to cover the upper surface and the side surface thereof. Further, as shown in FIG. 19B, the light diffusion reflection and transmission section 16 may have a plate shape and be provided so as to cover the upper part of the light-emitting element 14 while being separated from the light-emitting element 14. Further, as shown in FIG. 19C, the light diffusion reflection and transmission section 16 may have a rectangular shape and be adhered to the light-emitting element 14 and provided so as to cover the upper surface and the side surface thereof.

Explanation of Reference Numerals

[0103] 300,600 Laser light receiver 400,500 Light-receiving device 11 Substrate 12, 12a, 12b Light-receiving elements 13 Resin bank 14 Light-emitting element 15, 15A Translucent Dielectric 16, 16A Light Diffusing Reflection and Transmission Section 17 Adhesive 18 Light Receiver Circuit Board 19 Light Receiver Housing 21 Ceramic Frame 22 Band - Pass Filter 31, 32 Photovoltaic Conversion Element 33 Selector 34 Band - Pass Filter 35 Logarithmic Conversion Circuit 36 Analog - to - Digital Converter 37 Controller 38 Sound Generation Circuit 39 Speaker 40 Lighting Drive Circuit

Claims

1. A light receiving device that receives laser light emitted from a light emitting device, comprising: a substrate; at least one or more light receiving elements formed of a phototransistor provided on the substrate and having a light receiving surface on an upper surface; a light emitting element provided at a position spaced apart from the light receiving element on the substrate and having a light emitting surface on an upper surface; a light-transmissive dielectric formed to cover the light receiving element and the light emitting element; a light diffusing reflection and transmission portion provided at any position other than above the light receiving element on the light-transmissive dielectric, for diffusing light and reflecting and transmitting it; A light receiving device characterized by comprising the above.

2. The light receiving device according to claim 1, wherein the light-transmissive dielectric is a band-pass filter.

3. A light receiving device that receives laser light emitted from a light emitting device, comprising: a substrate; at least one or more light receiving elements formed of a phototransistor provided on the substrate and having a light receiving surface on an upper surface; a light emitting element provided at a position spaced apart from the light receiving element on the substrate and having a light emitting surface on an upper surface; a light diffusing reflection and transmission portion formed at any position in an area above the substrate except above the light receiving surface, for diffusing light and reflecting and transmitting it; A light receiving device characterized by comprising the above.

4. having a band-pass filter provided above so as to cover the light receiving element, transmitting the wavelength of the laser light, and not transmitting the wavelength of the light emitted by the light emitting element, The light receiving device according to claim 3, wherein the light emitting element and the light diffusing reflection and transmission portion are provided at positions not covered by the band-pass filter.

5. A light receiving device that receives laser light emitted from a light emitting device, comprising: a substrate; a light receiving element provided on the substrate and formed of a phototransistor having a light receiving surface on an upper surface; a light emitting element provided on the substrate and having a light emitting surface on an upper surface; a light diffusing reflection and transmission portion provided above the light emitting element, for diffusing light and reflecting and transmitting it; the light receiving element has a first light receiving surface and a second light receiving surface adjacent to each other with a boundary line therebetween; The light receiving device characterized in that at least one or more light emitting elements are provided on an extension of the boundary line.

6. having a band-pass filter provided above so as to cover the light receiving element, transmitting the wavelength of the laser light, and not transmitting the wavelength of the light emitting element, The light receiving device according to claim 5, wherein the light emitting element and the light diffusing reflection and transmission part are provided at a position not covered by the band pass filter.

7. The light receiving device according to any one of claims 1 to 6, wherein the light diffusing reflection and transmission part is made of a resin containing light scattering particles.

8. The light receiving device according to any one of claims 3 to 6, wherein the light diffusing reflection and transmission part is made of a resin containing light scattering particles formed so as to cover the upper and side portions of the light emitting surface of the light emitting element.

9. The light receiving device according to any one of claims 1 to 6, further comprising a power button and a display unit that optically indicates the on / off state of the power supply, wherein the backlight of the display unit also uses the light emitted from the light emitting element.

10. A light emitting device that emits laser light, A light receiving device having a substrate, at least one or more light receiving elements formed of a phototransistor provided on the substrate and having a light receiving surface on an upper surface, a light emitting element provided at a position spaced apart from the light receiving element on the substrate and having a light emitting surface on an upper surface, and a light-transmissive dielectric formed so as to cover the light receiving element and the light emitting element. A laser marking system, characterized by comprising the above.

11. The laser marking system according to claim 10, wherein the light emitting element is composed of a light emitting diode.

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