Light receiving device and laser marker system

Abstract

To provide a light receiving device capable of improving response characteristics of a light receiving element while suppressing an increase in a device scale.SOLUTION: A light receiving device that receives laser light emitted from a light emitting device includes a substrate, at least one light receiving element that is provided on the substrate and includes a phototransistor having a light receiving surface on an upper surface, a light emitting element that is provided at a position separated from the light receiving element on the substrate and has a light emitting surface on an upper surface, a translucent dielectric that is formed to cover the light receiving element and the light emitting element, and a light diffusion reflection / transmission portion that is provided at any position on the translucent dielectric except for a position above the light receiving element and diffuses, reflects, and transmits light.SELECTED DRAWING: Figure 4

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 marking device. [Background technology]

[0002] Laser markers are used to check the parallelism and perpendicularity of work surfaces during surveying at construction and civil engineering work sites. In measurements using a laser marker, a laser beam is emitted from the laser marker, and the parallelism and perpendicularity of the irradiated position are checked visually or based on the results received by a laser receiver.

[0003] Conventionally, laser receivers that receive laser light emitted from laser markers are required to be lighter and more compact because they are carried along with many tools during construction and civil engineering work. Laser receivers have traditionally used large-area photodiodes as light-receiving elements. Photodiodes have good response characteristics and can detect laser light even in dark places. However, the large area required not only increases the overall device size of the laser receiver but also increases costs. To reduce the light-receiving area, phototransistors with good sensitivity per unit area can be used instead of photodiodes. However, phototransistors have poor response characteristics and cannot detect laser light in dark places. Even if laser light is visible in dark places, if the laser receiver cannot detect it, it may be considered a malfunction of the laser receiver. One method for improving the response characteristics of phototransistors is to irradiate them with bias light (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 49-039072 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to achieve both a smaller light receiving area and compact size while maintaining 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 prior art. However, providing an illumination mechanism increases the size of the laser receiver device.

[0006] The present invention has been made in consideration of the above problems, and aims to provide a light receiving device to be mounted on a laser receiver that can improve the response characteristics of the light receiving element while reducing costs and preventing an increase in the size of the device. [Means for solving the problem]

[0007] The light receiving device of the present invention is a light receiving device that receives laser light emitted from a light emitting device, and is characterized by having a substrate, at least one light receiving element consisting of a phototransistor provided on the substrate and having a light receiving surface on its upper surface, a light emitting element provided at a position on the substrate away from the light receiving element and having a light emitting surface on its upper surface, a translucent dielectric formed to cover the light receiving element and the light emitting element, and a light diffusing reflecting / transmitting portion provided at any position on the translucent dielectric except above the light receiving element, which diffuses, reflects, and transmits light.

[0008] Furthermore, the light receiving device of the present invention is a light receiving device that receives laser light emitted from a light emitting device, and is characterized by having a substrate, a light receiving element consisting of a phototransistor that is provided on the substrate and has at least one light receiving surface on its upper surface, a light emitting element that is provided at a position spaced apart from the light receiving element on the substrate and has a light emitting surface on its upper surface, and a light diffusing, reflecting and transmitting portion that is formed at any position in the area above the substrate except above the light receiving surface and that diffuses, reflects and transmits light.

[0009] Furthermore, the light receiving device of the present invention is a light receiving device that receives laser light emitted from a light emitting device, and is characterized in that it comprises a substrate, a light receiving element consisting of a phototransistor provided on the substrate and having a light receiving surface on its upper surface, a light emitting element provided on the substrate and having a light emitting surface on its upper surface, a light diffusing reflection / transmission section provided above the light emitting element that diffuses, reflects and transmits light, the light receiving element having a first light receiving surface and a second light receiving surface adjacent to each other across a boundary line, and at least one of the light emitting elements being provided on an extension of the boundary line.

[0010] In addition, the laser marking system of the present invention is characterized by comprising a light-emitting device that emits laser light, a substrate, a light-receiving device having at least one or more light-receiving elements consisting of a phototransistor that is provided on the substrate and has a light-receiving surface on its upper surface, a light-emitting element that is provided at a position spaced apart from the light-receiving element on the substrate and has a light-emitting surface on its upper surface, and a translucent dielectric formed 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 explanation of the drawings]

[0012] [Figure 1] 1 is a diagram showing the configuration of a laser marking system according to a first embodiment of the present invention. [Figure 2] 1 is a top view of a light receiving device according to a first embodiment of the present invention. [Figure 3] 3 is an enlarged view of an area A1 surrounded by a dashed line in FIG. 2. FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. [Figure 5] 3 is a flowchart showing a manufacturing process of the light-receiving device of the first embodiment. [Figure 6A] 10 is a cross-sectional view of the light-receiving device in a printed circuit board preparation step. FIG. [Figure 6B]10A and 10B are cross-sectional views of the light-receiving device in a light-emitting element mounting step. [Figure 6C] 10A and 10B are cross-sectional views of the light-receiving device in a light-receiving element mounting step. [Figure 6D] 10A and 10B are cross-sectional views of a light-receiving device in a wire bonding process. [Figure 7A] 10A and 10B are cross-sectional views of the light-receiving device in a resin bank forming step. [Figure 7B] 10A and 10B are cross-sectional views of the light-receiving device in a translucent resin filling step. [Figure 7C] 10 is a cross-sectional view of the light-receiving device in a light diffusion reflection / transmission portion forming step. FIG. [Figure 8] FIG. 10 is a top view of a light-receiving device according to a second embodiment of the present invention. [Figure 9] 9 is an enlarged view of an area A2 surrounded by a dashed line in FIG. 8. FIG. [Figure 10] FIG. 10 is a cross-sectional view taken along line 10-10 in FIG. 9. [Figure 11] 10 is a flowchart showing a manufacturing process of the light-receiving device of Example 2. [Figure 12A] 10A and 10B are cross-sectional views of the light-receiving device in a ceramic frame mounting step. [Figure 12B] 10 is a cross-sectional view of the light-receiving device in a bandpass filter mounting step. FIG. [Figure 13] FIG. 10 is a cross-sectional view showing a light-receiving device according to a modified example of the first embodiment. [Figure 14] FIG. 10 is a top view of a laser receiver according to a third embodiment of the present invention. [Figure 15] FIG. 15 is a cross-sectional view taken along line aa in FIG. [Figure 16] FIG. 2 is a block diagram showing the internal configuration of the laser beam receiver. [Figure 17A] 10A and 10B are cross-sectional views showing modified examples of the position of the light diffusion reflection / transmission portion. [Figure 17B] 10A and 10B are cross-sectional views showing modified examples of the position of the light diffusion reflection / transmission portion. [Figure 18] FIG. 10 is a cross-sectional view showing a modified example of the laser receiver. [Figure 19A]10A and 10B are diagrams illustrating modified examples of the shape and position of the light diffusion reflection / transmission portion. [Figure 19B] 10A and 10B are diagrams illustrating modified examples of the shape and position of the light diffusion reflection / transmission portion. [Figure 19C] 10A and 10B are diagrams illustrating modified examples of the shape and position of the light diffusion reflection / transmission portion. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of each embodiment and the accompanying drawings, substantially the same or equivalent parts are designated by the same reference numerals. [Example]

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

[0015] The laser marking device 200 is a light-emitting device that emits laser light that serves as reference lines for construction, such as "horizontal" and "right angles," on walls, ceilings, and floors. By indicating vertical and horizontal lines with laser light, it is used to determine the installation locations of steel frames and reinforcing bars, and the mounting positions of fixtures, electrical outlets, etc. In this embodiment, the laser marking device 200 irradiates a line of light LT that extends horizontally toward the wall surface WL of a building.

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

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

[0018] Fig. 2 is a top view of a light-receiving device 400 according to a first embodiment of the present invention. The light-receiving device 400 is an electronic component that receives laser light and converts it into an electric signal, and is mounted on the light receiver 300 of 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 laser light emitted from the laser marking device (not shown) is irradiated in a line onto the surface of the light-receiving device 400.

[0019] The light-receiving device 400 includes a substrate 11, a light-receiving element 12 having two light-receiving surfaces adjacent to each other and provided 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 near the light-receiving element 12, and a light-transmitting dielectric 15 provided so as to fill the area surrounded by the resin bank 13. In this example, the light-receiving device 400 has a substantially rectangular shape in top view, with the x direction shown in FIG. 2 as the short side direction and the y direction as the long side direction.

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

[0021] The light receiving element 12 is composed of a phototransistor. A phototransistor is composed of a combination of a photodiode and a transistor (amplifier circuit), and has a sensitivity per unit area that is several tens to several hundreds times higher than that of a normal photodiode. In this embodiment, the light receiving element 12 is composed of a pair of phototransistors, each extending in one direction (the y direction in the figure) when viewed from above, arranged in a vertical row in the extension direction. The light receiving element 12 is arranged so that it has a light receiving surface on its upper surface, i.e., so that the light receiving surface faces upward in the normal direction of the substrate surface (i.e., 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 on the substrate 11 at a distance. In this embodiment, the resin bank 13 is made of silicone resin and has a ring-shaped configuration that surrounds the periphery of the light-receiving element 12 when viewed from above. The area surrounded by the resin bank 13 on the substrate 11 is filled with a translucent dielectric (not shown in FIG. 2).

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

[0024] A laser beam emitted from a laser marking device (not shown) is irradiated in a line onto the surface of the light receiving device 400 .

[0025] FIG. 3 is an enlarged view of an area A1 enclosed by a dashed line in FIG.

[0026] The light emitting element 14 has a rectangular shape when viewed from above. A light diffusing reflection / transmission portion 16 is formed on the surface of a translucent dielectric above the light emitting element 14. The light diffusing reflection / transmission portion 16 has the property of scattering the bias light emitted from the light emitting element 14, i.e., the property of diffusing, reflecting, and transmitting incident light. In this embodiment, the light diffusing reflection / transmission portion 16 is formed of a matte finish surface having a randomly uneven surface shape. Note that the light diffusing reflection / transmission portion 16 is not limited to such a surface having a randomly uneven surface shape, and may be formed of a light diffusing transmission film having a flat surface but with scattering particles dispersed therein.

[0027] The matte surface that constitutes the light diffuse reflection / transmission portion 16 is formed so as to cover an area wider than the upper surface of the light emitting element 14 when viewed from above. In this embodiment, the matte surface has an area that is wider than the upper surface of the light emitting element 14 by a width "h".

[0028] In this embodiment, a laser beam emitted from a laser marking device (not shown) is irradiated onto the surface of the light receiving device 400. The laser beam emitted from the laser marking device has a line shape extending along a direction (x direction in the drawing) perpendicular to the extension direction of the light receiving element 12.

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

[0030] A light receiving element 12 and a light emitting element 14 are provided on a substrate 11, and a resin bank 13 is formed to a height of "h" so as to surround the periphery of the elements. The light receiving element 12 and the light emitting element 14 are connected to the substrate 11 by wire bonding, but this is not shown here.

[0031] In the area surrounded by the resin bank 13, a light-transmitting dielectric 15 is formed so as to bury the light-receiving element 12 and the light-emitting element 14. The light-transmitting dielectric 15 is made of, for example, glass or a transparent resin such as epoxy or silicone.

[0032] A light diffusion reflecting / transmitting portion 16 is formed on the surface of the light-transmitting dielectric 15. The light diffusion reflecting / transmitting portion 16 is formed, for example, by adding a filler to the surface of the light-transmitting dielectric 15. Specifically, the light diffusion reflecting / transmitting 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 made 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 finish constituting the light diffuse reflection / transmission portion 16 can be controlled.

[0034] Alternatively, the matte surface may be formed by physically roughening the surface of the translucent dielectric 15. For example, the matte surface may be formed by blasting the surface of the translucent dielectric 15 to form irregularities. In this case, the irregularities formed preferably have a depth and width of sub-micrometers to several micrometers. Furthermore, the matte surface may be formed by forming irregularities by other surface processing methods other than blasting, such as engraving or laser processing.

[0035] Furthermore, the light diffusion reflection / transmission portion 16 may be a plastic light diffusion film in which inorganic particles (several μm or less) such as titanium oxide or zirconia, or acrylic or silicone organic particles (1 μm to 10-odd μm), or both inorganic and organic particles are dispersed in a film such as polyethylene terephthalate (PET), polycarbonate resin, or acrylic, and the plastic light diffusion film may be attached to the translucent dielectric 15 with a light-transmitting adhesive such as an acrylic adhesive, a silicone rubber adhesive, or a synthetic rubber adhesive.

[0036] Next, a method for manufacturing the light-receiving device 400 of this example 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 in Fig. 5.

[0037] 6A, a printed circuit board made of a glass epoxy board, a polyimide board, or the like is prepared (STEP 101). The printed circuit board has board areas corresponding to a plurality of light receiving devices arranged in a matrix, and is cut into individual board areas (boards 11) corresponding to each light receiving device by performing a singulation process in a wafer cutting process described later.

[0038] Next, as shown in FIG. 6B, the light emitting element 14 is mounted on the surface of the substrate 11 by die bonding (STEP 102).

[0039] Next, conductive adhesive 17 is applied to a position on substrate 11 at a predetermined distance from light emitting element 14, and light receiving element 12 is fixed by die bonding (STEP 103). As a result, a device is formed in which light emitting element 14 and light receiving element 12 are mounted on substrate 11, as shown in FIG. 6C.

[0040] 6D, the light-emitting element 14 and the light-receiving element 12 are connected to the substrate 11 by wire bonding (shown as WB in the figure) (STEP 104). For example, the emitter electrodes of the pair of phototransistors constituting the light-receiving element 12 are electrically connected to the pads of the emitter terminals of the printed circuit board constituting the substrate 11 by wire bonding using metal wires (gold, silver, etc.).

[0041] Next, a silicone resin is formed on the surface of the substrate 11 so as to surround the periphery of the phototransistor that constitutes the light-receiving element 12. For example, a dispenser is used to apply a light-opaque silicone resin with a high viscosity (for example, a room-temperature curing silicone resin with a viscosity of approximately 85 Pa·s) so as to surround the periphery of the light-receiving element 12. This forms a resin bank 13 as shown in FIG. 7A (STEP 105).

[0042] Next, a dispenser is used to fill the region surrounded by resin bank 13 with a light-transmitting silicone resin having a relatively low viscosity (for example, a viscosity of 1.3 to 1.7 Pa·s), thereby forming light-transmitting dielectric 15 so as to cover the region surrounded by resin bank 13, as shown in FIG. 7B (STEP 106).

[0043] Next, a resin containing light scattering particles is applied to the surface of the light-transmitting dielectric material 15 above (nearly directly above) the light-emitting element 14. As a result, the light diffuse reflection / transmission portion 16 is formed as shown in FIG. 7C (STEP 107).

[0044] The printed circuit board that has undergone the above steps is cut into individual board regions corresponding to the individual light receiving devices, thereby separating the light receiving devices (STEP 108).

[0045] Through the above steps, 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 onto the light-receiving device 400 and also receives the bias light emitted from the light-emitting element 14. This can improve the response characteristics of the light-receiving element 12.

[0047] The light-emitting element 14 is arranged so as to have a light-emitting surface on the upper surface, i.e., so that the light-emitting surface faces upward in the normal direction to the substrate surface, similar to the light-receiving surface of the light-receiving element 12. Therefore, the size in the height direction of the light-receiving device can be reduced compared to, for example, a case where the light-emitting element is arranged so that the light-emitting surface of the light-emitting element faces the light-receiving surface of the light-receiving element.

[0048] Furthermore, since the light diffusing reflecting / transmitting section 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 by the light diffusing reflecting / transmitting section 16. This allows the bias light component incident on the light receiving element 12 to be increased compared to when the light diffusing reflecting / transmitting section 16 is not provided.

[0049] Furthermore, the linear laser light emitted from the laser marking device is irradiated not only onto the light receiving element 12, but also onto the light emitting element 14 and its associated members. The irradiated laser light is reflected by the light emitting element 14 and its associated members, and enters the light receiving element 12. At this time, since the light receiving device 400 of this embodiment is provided with the light diffusing reflecting / transmitting portion 16 above the light emitting element 14, the laser light reflected by the light emitting element 14 and its associated members is scattered by the light diffusing reflecting / transmitting portion 16. As a result, the component of the laser light reflected by the light emitting element 14 and its associated members that enters the light receiving element 12 is reduced.

[0050] The refractive index of the glass or resin constituting the light-transmitting dielectric 15 is preferably about 1.4 to 1.6. As described above, the light diffusing, reflecting, and transmitting portion 16 covers an area wider than the upper surface of the light-emitting element 14 by the width "h" (i.e., about the same as the height of the resin bank 13) when viewed from above. Therefore, the critical angle is about 45 degrees, and the laser light can be prevented from reaching the light-emitting element 14. [Example]

[0051] 8 is a top view of a light-receiving device 500 according to Example 2 of the present invention. The light-receiving device 400 differs from the light-receiving device 400 of Example 1 in that a ceramic frame 21 is formed on the surface of the substrate 11 instead of a resin bank, and further in that a light diffuse reflection / transmission portion is formed on a bandpass filter provided on the ceramic frame 21.

[0052] The ceramic frame 21 is a frame body 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 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 when viewed from above.

[0053] FIG. 9 is an enlarged view of the area A2 enclosed by the dashed line in FIG.

[0054] The light diffuse reflection / transmission portion 16A is formed on a bandpass filter (not shown) provided on the ceramic frame 21. The matte surface constituting the light diffuse reflection / transmission portion 16A is formed so as to cover an area wider than the upper surface of the light emitting element 14 in top view, similar to the matte surface of Example 1, and has an area wider than the upper surface of the light emitting element 14 by a width "h".

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

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

[0057] A bandpass filter 22 is formed above the area of ​​the substrate 11 surrounded by the ceramic frame 21, spanning the ceramic frame 21. The bandpass filter 22 has the property of passing the laser light emitted from the laser marker and blocking light in other bands (particularly the bias light emitted from the light-emitting element 14). This makes it possible to distinguish the laser light from the laser marker from light such as sunlight and indoor lighting. In this embodiment, the bandpass filter 22 is made of an optical bandpass filter made of glass or acrylic that transmits green laser light. The bandpass filter 22 is adhered to the ceramic frame 21 with an adhesive.

[0058] A light diffuse reflection / transmission portion 16A made of a matte finish is formed on the bandpass filter 22. The matte finish is formed by performing surface processing such as blasting on the surface of the bandpass filter 22 (the surface corresponding to a position above the light emitting element 14) made of, for example, glass or acrylic. The matte finish is formed so as to have a surface roughness of 0.25 μm to several μm.

[0059] Alternatively, the light diffuse reflection / transmission section 16A may be made of a film of polyethylene terephthalate (PET), polycarbonate resin, acrylic, etc., and inorganic fine particles (several μm or less) of titanium oxide, zirconia, etc., or acrylic or silicone organic fine particles (1 μm to 10 μm). Alternatively, the light diffuse reflection / transmission section 16A may be made of, for example, a plastic light diffusion film in which both inorganic and organic fine particles are dispersed. In this case, the light diffuse reflection / transmission section 16A is formed by adhering the plastic light diffusion film to the surface of the bandpass filter 22 with a light-transmitting adhesive such as an acrylic adhesive, a silicone rubber adhesive, or a synthetic rubber adhesive.

[0060] Next, a method for manufacturing the light-receiving device 500 of this example 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 at some steps of the flowchart in Fig. 11.

[0061] STEPs 201 to 204 are the same as STEPs 101 to 104 in the first embodiment, and therefore a description thereof will be omitted here.

[0062] After 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, a ceramic frame 21 made of black ceramic is adhered to the surface of the substrate 11 using an adhesive. As a result, the ceramic frame 21 is formed so as to surround the periphery of the light receiving element 12, as shown in Fig. 12A (STEP 205).

[0063] Next, the optical bandpass filter, on which the light diffuse reflection / transmission portion 16A having a matte finish is formed by blasting, is adhered to the upper surface of the ceramic frame 21 using an adhesive so as to cover the upper part of the area surrounded by the ceramic frame 21. In this way, the bandpass filter 22 is mounted as shown in Fig. 12B (STEP 206).

[0064] The printed circuit board that has undergone the above steps is cut into individual board regions corresponding to the individual light receiving devices, thereby separating the light receiving devices (STEP 207).

[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 its upper surface, similar to the light-receiving device 400 of Example 1. A band-pass filter 22 is provided above the light-emitting surface of the light-emitting element 14. The band-pass filter 22 has the property of passing laser light emitted from a laser marking device and blocking 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. Therefore, the light-receiving device 500 of this embodiment can improve the response characteristics of the light-receiving element 12 while reducing the size of the light-receiving device in the height direction.

[0067] Furthermore, as in Example 1, a light diffusing reflecting / transmitting section 16A is formed above the light emitting surface of the light emitting element 14, and the bias light emitted from the light emitting element 14 is scattered in the light diffusing reflecting / transmitting section 16A, so that the component of bias light incident on the light receiving element 12 can be increased compared to when the light diffusing reflecting / transmitting section 16A is not present. [Example]

[0068] FIG. 14 is a top view of a laser beam receiver 600 according to a third embodiment of the present invention. The housing is not shown here. A light-receiving module having a light-receiving element 12 provided on the surface of a substrate 11 is provided on the surface of a receiver circuit board 18. The light-receiving element 12 is composed of a phototransistor. In this embodiment, the light-receiving element 12 is configured by a pair of phototransistors each having a shape extending in one direction (the y direction in the figure) when viewed from above, and arranged vertically in the extension direction. The light-receiving element 12 is arranged so that it has a light-receiving surface on its upper surface, i.e., so that the light-receiving surface faces upward in the normal direction of the substrate surface (i.e., the opposite direction to the vertical direction when the substrate 11 is placed horizontally on the receiver circuit board 18).

[0069] The light-emitting element 14 is formed on the surface of the light-receiving circuit board 18, and is disposed on an extension of the boundary line between the pair of phototransistors that make up the light-receiving element 12. A light-diffusing, reflecting, and transmitting section 16 is provided above the light-emitting element 14.

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

[0071] A light diffuse reflection / transmission section 16 is disposed above the light-emitting element 14 on the ceiling of the receiver housing 19. In this embodiment, the light diffuse reflection / transmission section 16 has a bullet-shaped cap shape. The light diffuse reflection / transmission section 16 may be composed of a film such as polyethylene terephthalate (PET), polycarbonate resin, or acrylic, and inorganic fine particles (several μm or less) such as titanium oxide or zirconia, or organic fine particles (1 μm to 10 μm) such as acrylic or silicone. Alternatively, the light diffuse reflection / transmission section 16 may be composed of a plastic light diffusion film in which both inorganic and organic fine particles are dispersed. In this case, the light diffuse reflection / transmission section 16 is formed by, for example, attaching the plastic light diffusion film to the receiver housing 19 with a light-transmitting adhesive such as an acrylic adhesive, a silicone rubber adhesive, or a synthetic rubber adhesive.

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

[0073] As shown in FIG. 16, the laser light receiver 600 includes photoelectric conversion elements 31, 32, a selector 33, a bandpass 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 on the light receiving surface into an electrical signal indicating the intensity of the light and supplies this as a first light receiving signal d1 to the selector 33. The photoelectric conversion element 32 converts the light received on the light receiving surface into an electrical signal indicating the intensity of the light and supplies this as a second light receiving signal d2 to the selector 33.

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

[0076] The bandpass filter 34 extracts signal components of a predetermined frequency band from the first light receiving signal d1 or the second light receiving signal d2 supplied from the selector 33, and supplies a light receiving signal df consisting of the extracted signal components to the logarithmic conversion circuit 35.

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

[0078] The analog-to-digital converter 36 converts the value indicated by the received-light intensity signal dlg into a digital value, and supplies the digital value as a received-light intensity data signal DT 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 also receives the received light intensity data signal DT in accordance with a laser irradiation position determination program stored in the ROM 371 .

[0081] In addition, the controller 37 generates a buzzer sound signal BS instructing no buzzer sound, or a buzzer sound signal BS instructing the output of a buzzer sound and specifying the scale of the buzzer sound (for example, the note "do"), 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 that instructs one of the light-emitting elements Lr, Ly, and Lg to be turned on, or a lighting control signal LS that instructs all of the light-emitting elements Lr, Ly, and Lg to be turned off, 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 instructing the output of a buzzer sound, it generates a sound signal having a waveform of a buzzer sound of the scale specified by the buzzer sound signal BS and supplies this to the speaker 39. As a result, the speaker 39 outputs a buzzer sound based on this sound signal to the outside through the sound hole. On the other hand, when the sound generation circuit 38 receives a buzzer sound signal BS indicating that the buzzer should not sound, it supplies a sound signal indicating silence to the speaker 39. As a result, the speaker 39 enters a silent state in which it does not output any sound.

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

[0085] Furthermore, 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 the light-emitting elements Lr, Ly, and Lg, thereby turning off all of the light-emitting elements Lr, Ly, and Lg.

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

[0087] It should be noted 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 translucent dielectric 15 is formed by filling the area surrounded by the resin bank 13 with a translucent silicone resin. However, the shape of the translucent dielectric is not limited to this.

[0088] 13, a plate-shaped light-transmitting dielectric 15A (i.e., a light-transmitting plate) made of glass or a resin such as epoxy or silicone may be placed 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. Even in a light-receiving device having such a configuration, it is possible to form a matte finish as the light-diffusing, reflecting, and transmitting portion 16 by subjecting the light-transmitting dielectric 15A to physical surface processing.

[0089] Furthermore, in the above-mentioned second embodiment, a configuration in which the bandpass filter 22 is provided above the region surrounded by the ceramic frame 21 of the substrate 11 (i.e., the configuration of Figure 10) has been described, but it is also possible to fill the region with a translucent dielectric similar to that of the first embodiment up to a height below the ceramic frame 21, and place the bandpass filter 22 on the upper surface of the translucent dielectric.

[0090] Alternatively, the light diffusion reflection / transmission portion may be a plastic light diffusion film in which inorganic particles (several μm or less) such as titanium oxide or zirconia, or acrylic or silicone organic particles (1 μm to several 10 μm), or both inorganic and organic particles are dispersed in a film such as polyethylene terephthalate (PET), polycarbonate resin, or acrylic, and the plastic light diffusion film may be attached to the surface of the bandpass filter 22 with a light-transmitting adhesive such as an acrylic adhesive, a silicone rubber adhesive, or a synthetic rubber adhesive.

[0091] In addition, in the above-described Examples 1 and 2, 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 position where the light diffusion reflection / transmission portion 16 (16A) is formed 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] 17A is a cross-sectional view showing a modified light-receiving device in which the light diffusion reflection / transmission section 16 is disposed at a position other than directly above the light-emitting element 14. A band-pass filter 22 is provided so as to cover the light-emitting element 14 and a light-receiving module consisting of a substrate 11 and a light-receiving element 12. The light diffusion reflection / transmission section 16 is provided on the inner surface of the band-pass filter 22 (i.e., the surface facing the substrate 11) in a portion located between the upper part of the light-emitting element 14 and the upper part of the light-receiving element 12.

[0093] For example, if the light-emitting element 14 is composed of an LED (Laser Emitting Diode) chip, the light emitted from the LED generally spreads without directionality, and 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. Therefore, the light-diffusing reflecting / transmitting portion 16 may be positioned at a location where the emitted light can reach, and may be positioned away from directly above the light-emitting element 14, as shown in FIG. 17A. By positioning the light-diffusing reflecting / transmitting portion 16 at such a location, the bias light can be incident on the light-receiving surface of the light-receiving element without increasing the thickness (height) of the light-receiving device. For example, if the light-emitting element 14 has the light distribution characteristics of a typical LED chip, the relative illuminance is high in an angle range of approximately 30° to 60° with respect to the normal direction of the light-emitting surface. Therefore, by positioning the light-diffusing reflecting / transmitting portion 16 in this vicinity, more light can reach the light-receiving element 12.

[0094] 17B is a cross-sectional view showing a modified light-receiving device in which a box-shaped light-receiving module is provided so as to surround the light-receiving module, and the light diffuse reflection / transmission unit 16 is disposed in a position that is not directly above the light-emitting element 14. The band-pass filter 22 is disposed in a ceiling portion of the light-receiving module housing 19, including above the light-receiving element 12. An opening is also provided in the ceiling portion of the light-receiving module housing 19 above the light-emitting element 14. The light diffuse reflection / transmission unit 16 is disposed in a position between the opening in the ceiling portion of the light-receiving module housing 19 and the band-pass filter 22.

[0095] Arranging the light diffusion reflecting / transmitting portion 16 at a position not directly above the light emitting element 14 is also useful from the viewpoint of preventing stray light of laser light. That is, with this configuration, when laser light incident from outside the light receiving device (for example, a laser emitting device) is irradiated onto the light emitting element 14, the scattered light, i.e., stray light, can be prevented from entering the light receiving element 12.

[0096] 17A to the area directly above the light-emitting element 14. As described above, the light-diffusing reflecting / transmitting element 16 may be provided in any area above the substrate 11, excluding the area above the light-receiving element 12.

[0097] Furthermore, the method for manufacturing a light-receiving device is not limited to the methods 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 STEP 104, the resin bank 13 is formed in STEP 105, and the light-transmitting dielectric 15 is formed by filling the area surrounded by the resin bank 13 with a light-transmitting silicone resin in STEP 106. However, differently from this, after STEPs 101 to 104, the light-transmitting dielectric 15 may be formed by applying a light-transmitting epoxy resin to the front surface of the substrate and curing it.

[0098] Furthermore, the contents described in each of the above embodiments can be used in appropriate combination. For example, in the above embodiment 1, the frame body surrounding the light receiving element 12 is composed of the resin bank 13, and in the above embodiment 2, the frame body is composed of the ceramic frame 21. However, for example, in embodiment 1, a ceramic frame similar to that in embodiment 2 may be used instead of the resin bank 13.

[0099] Furthermore, in the third embodiment, the light diffusion reflection / transmission section 16 is made of a film, but the light diffusion reflection / transmission section 16 may be made of a plastic light diffusion plate or a plastic light diffusion cap.

[0100] Furthermore, by adjusting the distribution of the fine particles used in the light diffusing / reflecting / transmitting portion 16 according to the amount of light emitted from the light emitting element, it is possible to adjust the visibility of the power lamp and the phototransistor response performance of the bias light. For example, if the amount of light incident on the light receiving element 12 as bias light is large, the amount of fine particles may be reduced or the particle size may be made smaller. If it is desired to reduce the light amount of the power lamp and increase the light amount of the 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 optical receiver circuit board 18 has been described as an example. However, the position of the light-emitting element 14 is not limited to this, and the light-emitting element 14 may be provided on the surface of the substrate 11, for example, as shown in Fig. 18. In this case, the light diffuse reflection / transmission unit 16 located above the light-emitting element 14 is located closer to the band-pass filter 22 than in Fig. 15.

[0102] In addition, in Example 3, as shown in FIG. 15 , the light diffusion reflection / transmission portion 16 has a bullet-shaped cap shape and is spaced apart from the light emitting element 14 to cover the upper part of the light emitting element 14. However, the position and shape of the light diffusion reflection / transmission portion 16 are not limited thereto. For example, as shown in FIG. 19A , the light diffusion reflection / transmission portion 16 having a bullet shape may be bonded to the light emitting element 14 to cover its upper and side surfaces. Furthermore, as shown in FIG. 19B , the light diffusion reflection / transmission portion 16 may have a plate-like shape and be spaced apart from the light emitting element 14 to cover its upper part. Furthermore, as shown in FIG. 19C , the light diffusion reflection / transmission portion 16 may have a rectangular shape and be bonded to the light emitting element 14 to cover its upper and side surfaces. [Explanation of symbols]

[0103] 300,600 Laser light receiver 400,500 light receiving devices 11 Circuit Board 12, 12a, 12b Light receiving element 13 Resin Bank 14 Light-emitting element 15,15A Translucent dielectric 16,16A Light diffusion reflection transmission part 17 Adhesive 18 Receiver circuit board 19 Receiver housing 21 Ceramic Frame 22 Bandpass Filter 31,32 Capacitive transducer 33 Selector 34 Bandpass 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, A substrate; At least one light receiving element, which is a phototransistor provided on the substrate and has a light receiving surface on its upper surface; a light-emitting element provided on the substrate at a position spaced apart from the light-receiving element and having a light-emitting surface on an upper surface thereof; a light-transmitting dielectric formed to cover the light-receiving element and the light-emitting element; a light diffusion reflection / transmission portion that is provided at any position on the light-transmitting dielectric body except above the light-receiving element and that diffuses and reflects and transmits light; A light receiving device comprising:

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

3. A light receiving device that receives laser light emitted from a light emitting device, A substrate; At least one light receiving element, which is a phototransistor provided on the substrate and has a light receiving surface on its upper surface; a light-emitting element provided on the substrate at a position spaced apart from the light-receiving element and having a light-emitting surface on an upper surface thereof; a light diffusion reflection / transmission section formed at any position in an area above the substrate excluding an area above the light receiving surface, the light diffusion / reflection / transmission section diffusing and reflecting and transmitting light; A light receiving device comprising:

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

5. A light receiving device that receives laser light emitted from a light emitting device, A substrate; a light-receiving element provided on the substrate and including a phototransistor having a light-receiving surface on an upper surface thereof; a light-emitting element provided on the substrate and having a light-emitting surface on an upper surface thereof; a light diffusion reflection / transmission section provided above the light emitting element, which diffuses and reflects and transmits light; the light receiving element has a first light receiving surface and a second light receiving surface adjacent to each other across a boundary line; The light receiving device is characterized in that at least one of the light emitting elements is provided on an extension of the boundary line.

6. a bandpass filter provided above the light receiving element so as to cover the light receiving element, the bandpass filter transmitting the wavelength of the laser light and blocking the wavelength of the light emitting element; 6. The light receiving device according to claim 5, wherein the light emitting element and the light diffusing reflection / transmission portion are provided at positions not covered by the bandpass filter.

7. 7. The light receiving device according to claim 1, wherein the light diffusing reflection / transmission portion is made of a resin containing light scattering particles.

8. 7. The light receiving device according to claim 3, wherein the light diffusing reflection / transmission portion is made of a resin containing light scattering particles formed so as to cover the upper and side portions of the light emitting element's light exit surface.

9. 7. The light receiving device according to claim 1, further comprising a power button and a display unit that indicates the on / off state of the power supply with light, and 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 including: a substrate; at least one light-receiving element formed on the substrate and consisting of a phototransistor having a light-receiving surface on its upper surface; a light-emitting element provided on the substrate at a position spaced apart from the light-receiving element and having a light-emitting surface on its upper surface; and a light-transmitting dielectric formed so as to cover the light-receiving element and the light-emitting element; A laser marking system comprising:

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

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