JP2004349579A - Optical unit and photosensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small sized optical unit having a function of receiving and emitting light. <P>SOLUTION: An optical module 2 is adapted such that a die pad 7 is mounted in a package 6 to form a first cavity 9 and a second cavity 10. A light source 4 is mounted on one surface of the die pad 7, while a photodiode 5 is mounted on the other surface of the same. An aperture 12 through which light emitted from the light source 4 passes is provided in the first cavity 9, and a window part 16 through which light incident on the photodiode 5 passes is provided in the second cavity 10. An optical housing 3 includes a condenser 17 for collecting light and a light guide 18 having a reflective surface 18b for deflecting the advance direction of the light toward the photodiode 5. The optical unit 1 for permitting reflected light of the light emitted from the light source 4 to enter the photodiode 5 is constructed by mounting the optical housing 3 on the optical module 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical unit and an optical sensor that house a light emitting unit and a light receiving unit in a single package. In detail, a light emitting unit is mounted on one surface of a die pad in a package, and a light receiving unit is mounted on the other surface. The size of the whole unit is reduced, and the versatility is improved.
[0002]
[Prior art]
An optical component including a light emitting element that emits light and a light receiving element that receives light utilizes, for example, the presence or absence of an object to be detected by utilizing the fact that the output voltage changes depending on whether light enters the light receiving element. Used as a sensor to detect. Conventionally, a light emitting element and a light receiving element are housed in independent packages, respectively, and these packages are used in a form mounted on a substrate or the like.
[0003]
On the other hand, there has been proposed an optical component in which a light emitting element and a light receiving element are mounted in a single package. For example, a light emitting element and a light receiving element are provided in parallel on the surface of a substrate, and the light emitting element and the light receiving element are integrated by a resin mold, so that the light emitting element and the light receiving element are mounted in a single package. (For example, refer to Patent Document 1).
[0004]
[Patent Document 1]
JP-A-2000-244409.
[0005]
[Problems to be solved by the invention]
In an optical component in which a light emitting element and a light receiving element are housed in independent packages, there is a problem that adjustment of an optical axis or the like is required when mounting each package. In addition, there is a problem that the size of the optical component becomes large and a large occupied space is required, so that a place where the optical component can be installed is restricted.
[0006]
In addition, even with optical components in which a light-emitting element and a light-receiving element are mounted in a single package, in a configuration in which the light-emitting element and the light-receiving element are arranged in parallel, the size of the optical part cannot be reduced so much, and the place where it can be installed is limited. There was a problem that occurred.
[0007]
An optical component in which a light-emitting element and a light-receiving element are mounted in a single package is generally designed exclusively for use, and thus has a problem that it is not versatile and costs high.
[0008]
The present invention has been made to solve such a problem, and an object of the present invention is to provide a small and highly versatile optical unit and an optical sensor using the optical unit.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, an optical unit according to the present invention includes an optical module in which a light emitting unit and a light receiving unit are housed in a single package, and is attached to the optical module to allow external light to enter the light receiving unit. An optical housing, wherein the optical module is mounted inside the package to form a first cavity and a second cavity, and a light emitting means is mounted on a side facing the first cavity; A die pad on which the light receiving means is mounted on the side facing the first, a first opening provided in the first cavity, through which light emitted from the light emitting means passes, and a light emitting means provided in the second cavity. The optical housing includes a second opening through which light passes, and the optical housing includes a light-collecting unit that collects light from the outside and a traveling direction of the light collected by the light-collecting unit to the light-receiving unit. Only to those with a light path changing means for bending.
[0010]
Further, an optical sensor according to the present invention includes the above-described optical unit. That is, the optical module includes an optical module in which a light emitting unit and a light receiving unit are housed in a single package, and an optical housing attached to the optical module and configured to allow external light to enter the light receiving unit. A die pad mounted to form a first cavity and a second cavity, wherein a light emitting means is mounted on a side facing the first cavity, and a light receiving means is mounted on a side facing the second cavity; An optical housing, comprising: a first opening provided in the first cavity, through which light emitted from the light emitting means passes; and a second opening provided in the second cavity, through which light entering the light receiving means passes. Is provided with a condensing means for condensing light from the outside, and an optical path changing means for bending the traveling direction of the light condensed by the condensing means toward the light receiving means. On the extension of the optical axis passing through the first opening, it is obtained by setting the detection position of the detected object.
[0011]
According to the optical unit and the optical sensor according to the present invention, the light emitted from the light emitting unit is emitted from the first opening without bending the optical path. When the object to be detected is opposed to the first opening and is located on the optical axis of the light emitted from the first opening, the light emitted from the optical module is reflected by the object to be collected and collected by the optical housing. Light enters the light means. The light incident on the light condensing means is condensed, and the traveling direction is bent by the light path changing means. Thus, the light collected by the light collecting means enters the light receiving means from the second opening.
[0012]
The optical module constituting the optical unit has a light emitting unit mounted on one surface of the die pad and a light receiving unit mounted on the other surface, so that the space required for mounting the light emitting unit and the light receiving unit is small. I'm done. Thereby, the size of the package can be reduced. Further, since the inside of the package is partitioned by a die pad to form a first cavity in which the light emitting means is mounted and a second cavity in which the light receiving element is received, light emitted from the light emitting means is directly sent to the light receiving means in the package. There is no incidence. Therefore, since a separate member for shielding light is not required, the size of the package can be reduced.
[0013]
Then, by attaching the optical housing to the optical module, reflected light of light emitted from the light emitting means mounted on one surface of the die pad can be incident on the light receiving means mounted on the other surface of the die pad.
[0014]
Thus, a small-sized optical unit capable of receiving the reflected light of the light emitted from the light emitting means by the light receiving means can be configured, so that a highly versatile optical unit and optical sensor can be provided.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the optical unit of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view illustrating a configuration example of the optical unit according to the first embodiment, FIG. 2 is a plan view illustrating the internal configuration of the optical unit, and FIG. 3 is an external perspective view of the optical unit. Here, the cut surface in FIG. 1 is a line AA shown in FIG. 2, but only a package, a cover, and a light guide, which will be described later, are shown in cross-section. FIG. 2 is a plan view of the optical unit 1 in FIG. 1 as viewed from the direction of arrow B. However, in order to show the internal configuration of the optical unit 1, the optical unit 1 is shown without a cover.
[0016]
The optical unit 1 according to the first embodiment is obtained by attaching an optical housing 3 to an optical module 2. The optical module 2 includes a light source 4 as an example of a light emitting unit and a photodiode (PD) 5 as an example of a light receiving unit. The optical housing 3 is attached so that light from the outside is incident on the photodiode 5.
[0017]
Hereinafter, the configuration of the optical module 2 will be described first. The optical module 2 includes a light source 4 and a photodiode 5 inside a package 6. The package 6 is formed by molding a resin or the like into a predetermined shape, and has a rectangular parallelepiped outer shape. As an example, the size of the package 6 is such that the length in the long side direction is 6 mm, the length in the short side direction is 3.4 mm, and the height is 2.6 mm.
[0018]
This package 6 is formed integrally with conductive members such as a die pad 7 and a lead 8 formed of a lead frame (not shown). For example, a plurality of leads 8 protrude from one side of the package 6.
[0019]
As shown in FIG. 1, the die pad 7 is provided so as to partition a part inside the package 6 in the height direction. Thus, inside the package 6, the first cavity 9 is formed on one surface side of the die pad 7, and the second cavity 10 is formed on the other surface side of the die pad 7. A configuration for light emission is provided on the first cavity 9 side, and a configuration for light reception is provided on the second cavity 10 side.
[0020]
Next, the configuration of the light emitting side of the optical module 2 will be described. The light source 4 is a laser-on-photodiode (LOP) composed of, for example, a laser diode and a PIN photodiode for monitoring the amount of light emitted from the laser and keeping the emission power constant. The light source 4 is mounted on one surface of the die pad 7 facing the first cavity 9 using silver paste or the like.
[0021]
The first cavity 9 is provided with a land 8a electrically connected to a predetermined lead 8, and a laser diode or a photodiode constituting the light source 4 is electrically connected to the land 8a by a wire 11. . Here, the light irradiation direction of the light source 4 is substantially parallel to the surface of the die pad 7.
[0022]
The first cavity 9 has an aperture 12 as a first opening provided with a diaphragm. The aperture 12 is an opening of a predetermined shape provided on one side wall of the package 6 constituting the first cavity 9, and is located on the optical axis of light emitted from the light source 4. Light emitted from the light source 4 passes through the aperture 12 and is emitted to the outside of the package 6 as a beam narrowed to a desired shape. The aperture 12 is formed when the package 6 is molded.
[0023]
The first cavity 9 has a lens mounting part 13 between the die pad 7 and the aperture 12. A light projecting lens 14 as light projecting means for condensing the light emitted from the light source 4 is attached to the lens attaching section 13.
[0024]
The light projecting lens 14 is a spherical ball lens, and the lens mounting portion 13 is formed, for example, by forming a hole having a diameter smaller than the diameter of the light projecting lens 14 when the package 6 is molded. The light projecting lens 14 is placed on the lens mounting portion 13 and fixed using an adhesive such as a UV curing resin.
[0025]
Due to this, from the relationship between the diameter of the light projecting lens 14, the position where the lens mounting part 13 is provided, and the diameter of the lens mounting part, when the light projecting lens 14 is mounted on the lens mounting part 13, The position of the center in the three-dimensional direction is uniquely determined.
[0026]
The mounting position of the light projecting lens 14 is set so that the optical axis of the light emitted from the light source 4 and the center of the light projecting lens 14 coincide. Here, the light projecting lens 14 may be other than a ball lens, but by using a ball lens, the light projecting lens 14 can be mounted at a predetermined position without considering the mounting direction. In addition, the shape of the lens attachment part 13 is an example.
[0027]
The first cavity 9 has an opening at a portion facing one surface of the die pad 7, and after mounting the light projecting lens 14 and the like, a cover 15 is attached to this opening and sealed. Here, the hole constituting the lens mounting portion 13 does not penetrate to the outer wall of the package 6 or the second cavity 10. Thus, the light emitted from the light source 4 does not leak directly to the second cavity 10 inside the package 6.
[0028]
The light emitted from the light source 4 passes through the light projecting lens 14 and is radiated from the aperture 12 to the outside of the package 6. The focal point of the emitted light is determined by the distance between the light emitting point of the light source 4 and the light projecting lens 14, and the aperture 12 narrows the beam shape of the light to a desired shape. As a result, the required light spot size and shape can be obtained at a desired position on the optical axis of the light emitted from the light source 4.
[0029]
Next, the configuration of the light receiving side of the optical module 2 will be described. The photodiode 5 is mounted on the other surface of the die pad 7 facing the second cavity 10 using a silver paste or the like.
[0030]
FIG. 4 is a plan view of the optical module 2 and shows a configuration of the second cavity 10. Here, FIG. 4 is a plan view of the optical module 2 to which the optical housing 3 is not attached in the optical unit 1 of FIG.
[0031]
The second cavity 10 is provided with a land portion 8b that is electrically connected to a predetermined lead 8. The photodiode 5 is electrically connected to the land portion 8b by a wire 11, and the light incident on the photodiode 5 Is output from a predetermined lead 8.
[0032]
The second cavity 10 has a window 16 as a second opening. The window portion 16 is an opening provided in a portion of the package 6 constituting the second cavity 10 facing an incident surface (not shown) of the photodiode 5, and is formed when the package 6 is molded. Here, light enters the photodiode 5 from a direction substantially orthogonal to the die pad 7.
[0033]
Thus, in the optical module 2, the direction of the light emitted from the light source 4 and the direction of the light incident on the photodiode 5 are substantially orthogonal. Then, the optical housing 3 is attached to the optical module 2 in order to make the light incident substantially parallel to the light emitted from the light source 4 incident on the photodiode 5.
[0034]
Hereinafter, the configuration of the optical housing 3 will be described. The optical housing 3 includes a condenser lens 17 as an example of a condenser, and a light guide 18 constituting an optical path changing unit. The optical housing 3 is provided with a bandpass filter (BPF) 19 for selecting only the wavelength of light emitted from the light source 4 as necessary. The condenser lens 17 condenses the light incident on the photodiode 5 and focuses the light on an incident surface (not shown) of the photodiode 5.
[0035]
The light guide 18 is made of a transparent resin such as acrylic or polycarbonate, and has a lens mounting portion 18a, a reflecting surface 18b, and a package mounting portion 18c integrally formed.
[0036]
The lens mounting portion 18a is constituted by a hole or the like corresponding to the diameter of the condensing lens 17, and the condensing lens 17 and the band pass filter 19 are fitted to the lens mounting portion 18a and adhered by, for example, a UV curing resin. It is fixed using an agent.
[0037]
The reflection surface 18b is an inclined surface having an inclination of 45 degrees with respect to the optical axis of the condenser lens 17 attached to the lens attachment portion 18a, and reflects (total reflection) light that has passed through the condenser lens 17, and Is bent by 90 °.
[0038]
The package mounting portion 18c has, for example, a shape that matches the shape of the surface on which the window 16 of the package 6 is provided. Then, the light guide 18 is fixed with an adhesive made of, for example, a UV curable resin or the like by abutting the package mounting portion 18c against the surface of the package 6 where the window 16 is provided.
[0039]
The structure for fixing the light guide 18 to the package 6 is not limited to the adhesive, but may be a structure in which a fitting claw or the like is provided on the light guide 18 and the fitting claw is fitted to the package 6 and fixed.
[0040]
When the optical housing 3 having the above-described configuration is attached to the optical module 2, the condenser lens 17 is provided at a position parallel to the aperture 12. The optical axis of the condenser lens 17 is substantially parallel to the optical axis of the light emitted from the light source 4. Further, the reflection surface 18b faces the photodiode 5.
[0041]
As a result, the light incident on the condenser lens 17 is reflected by the reflection surface 18 b, the traveling direction is bent by 90 °, and the light enters the photodiode 5. The incident light is condensed by the condenser lens 17 and is focused on an incident surface (not shown) of the photodiode 5.
[0042]
By providing the condenser lens 17 at a position parallel to the aperture 13, the optical path length from the condenser lens 17 to the photodiode 5 can be increased. Therefore, a lens having a large curvature and a surface shape close to a plane can be used as the condenser lens 17. Thus, instead of the configuration in which the bandpass filter 19 is provided separately from the condenser lens 17, a configuration in which a bandpass layer is directly formed on the surface of the condenser lens 17 can be adopted.
[0043]
Further, a configuration in which light with a wavelength equal to or less than the addition of a small amount of arsenic or the like is cut off and combined with a lens may be used. Further, when used in an environment that is not affected by external light, the bandpass filter 19 may not be necessary.
[0044]
Next, a second embodiment of the optical unit will be described. FIG. 5 is a cross-sectional view illustrating a configuration example of the optical unit according to the second embodiment. The optical unit 21 according to the second embodiment is obtained by attaching an optical housing 22 to the optical module 2 described in the first embodiment. Here, the optical module 2 is the same as the optical module 2 of the optical unit 1 of the first embodiment described with reference to FIGS. 1 to 4, and the description of the configuration is omitted here.
[0045]
The optical housing 22 has a case 24 in which a condenser lens 17 as an example of a condensing unit and a reflection mirror 23 as an example of an optical path changing unit are housed. Further, the optical housing 22 is provided with a bandpass filter 19 for selecting only the wavelength of the light emitted from the light source 4 as necessary, similarly to the optical unit 1 of the first embodiment. The condenser lens 17 condenses the light incident on the photodiode 5 and focuses the light on an incident surface (not shown) of the photodiode 5.
[0046]
The case 24 is made of a resin that does not transmit light, and has a lens mounting portion 24a, a mirror mounting portion 24b, and a package mounting portion 24c, for example, integrally configured.
[0047]
The lens mounting portion 24a is formed of a hole or the like corresponding to the diameter of the condensing lens 17, and the condensing lens 17 and the band pass filter 19 are fitted to the lens mounting portion 24a and bonded by, for example, a UV curing resin. It is fixed using an agent.
[0048]
The mirror mounting portion 24b is a slope having an inclination of 45 degrees with respect to the optical axis of the condenser lens 17 mounted on the lens mounting portion 24a, and the reflection mirror 23 is mounted on the mirror mounting portion 24b by bonding or the like. Here, the reflection mirror 23 is mounted on the optical axis of the condenser lens 17. Thus, the light that has passed through the condenser lens 17 is reflected by the reflection mirror 23, and the traveling direction of the light is bent by 90 °.
[0049]
The package mounting portion 24c has, for example, a shape that matches the shape of the surface on which the window 16 of the package 6 is provided. Then, the case 24 is fixed with an adhesive made of, for example, a UV curable resin or the like by abutting the package mounting portion 24c against the surface of the package 6 where the window 16 is provided.
[0050]
The structure for fixing the case 24 to the package 6 is not limited to the adhesive, but may be a structure in which a fitting claw or the like is provided on the case 24 and the fitting claw is fitted to the package 6 and fixed.
[0051]
When the optical housing 22 having the above-described configuration is attached to the optical module 2, the condenser lens 17 is provided at a position parallel to the aperture 12. The optical axis of the condenser lens 17 is substantially parallel to the optical axis of the light emitted from the light source 4. Further, the reflection mirror 23 faces the photodiode 5.
[0052]
As a result, the light incident on the condenser lens 17 is reflected by the reflection mirror 23, the traveling direction is bent by 90 °, and is incident on the photodiode 5. The incident light is condensed by the condenser lens 17 and is focused on an incident surface (not shown) of the photodiode 5.
[0053]
Here, also in the optical unit 21 according to the second embodiment, modifications such as forming a band-pass filter on the surface of the condenser lens 17 are described in the optical unit 1 according to the first embodiment. Is the same as
[0054]
Next, use examples of the optical unit according to the first embodiment and the second embodiment will be described. Note that the following description is made using the optical unit 1 according to the first embodiment as an example, but the same applies to the optical unit according to the second embodiment.
[0055]
FIG. 6 is an explanatory diagram showing an example of use of the optical unit 1. The optical unit 1 is used as, for example, a reflection-type optical sensor that detects the presence or absence or passage of an object 25 at a predetermined distance.
[0056]
The light emitted from the light source 4 is condensed by the light projecting lens 14 and emitted from the package 6 to the outside as a beam narrowed to a predetermined shape by the aperture 12. When the object 25 is positioned in front of the aperture 12, that is, on the optical axis of the light source 4, the light emitted from the light source 4 is reflected by the object 25 and returns to the optical unit 1. In FIG. 6, the light emitted from the light source 4 is indicated by a solid line, and the light reflected by the object 25 is indicated by a broken line.
[0057]
Part of the light reflected by the object 25 returns to the optical unit 1 and enters the bandpass filter 19 and the condenser lens 17. In the band pass filter 19, only the light of the wavelength emitted from the light source 4 is transmitted. This prevents other external light from entering. The condensing lens 17 condenses the incident light.
[0058]
Here, the light enters the condenser lens 17 at an angle substantially parallel to the light emitted from the light source 4. Then, the light that has passed through the condenser lens 17 is reflected by the reflection surface 18b of the light guide 18, and the traveling direction is bent by 90 °. The light reflected by the light guide 18 enters the photodiode 5 because the reflection surface 18b and the photodiode 5 face each other. When the return light from the light source 4 enters the photodiode 5, a predetermined voltage is output from the lead 8. Thus, the presence of the detection target 25 can be detected.
[0059]
The light incident on the photodiode 5 is condensed by the condenser lens 17 so as to be focused on an incident surface (not shown) of the photodiode 5. Here, in the optical unit 1, since the condenser lens 17 is provided in parallel with the aperture 12, the optical path length from the condenser lens 17 to the photodiode 5 can be made longer. Thus, the design of the condenser lens 17 for focusing on the photodiode 5 is easy.
[0060]
For example, in a configuration in which a condenser lens is provided in the window 16 of the package 6, the distance between the condenser lens and the photodiode 5 is short, and it is difficult to focus on the photodiode 5 with a normal lens. Further, a configuration in which incident light is not focused on the incident surface of the photodiode 5 is possible, but in this case, a photodiode having a large incident surface area must be used.
[0061]
On the other hand, in the optical unit 1, since the incident light can be focused on the incident surface of the photodiode 5 without using a lens having a special configuration, the incident surface of the photodiode 5 can be minimized. And cost can be reduced.
[0062]
When the optical unit 1 is used as an optical sensor for detecting an object to be detected, the optical unit 1 needs to be accurately attached to a position where the object 25 is to be detected.
[0063]
In the optical unit 1, the light emitted from the light source 4 is condensed by the light projecting lens 14 and radiated to the outside as a beam having a predetermined shape through the aperture 12. And does not bend the optical path. Therefore, if the detection position of the detection target 25 is set on the optical axis of the light source 4, the light emitted from the light source 4 can be used without bending the optical path.
[0064]
Thus, by positioning the optical unit 1 with reference to the outer shape of the package 6 of the optical module 2, it is easy to mount the optical unit 1 so that a beam of light emitted from the light source 4 passes through a desired detection position. Can be done.
[0065]
Further, the beam of the light emitted from the light source 4 is set by the light projecting lens 14 so as to be focused on the detection target 25 at a predetermined distance, but as shown by a two-dot chain line in FIG. Even when the distance of the detection unit 25 changes, the detection target 25 is located on the optical axis of the light emitted from the light source 4 and is out of focus, but the beam itself is reflected by the detection target 25. Accordingly, the optical unit 1 can detect the presence or absence of the detection target 25 even if the distance to the detection target 25 changes.
[0066]
FIG. 7 is an explanatory diagram showing a configuration example of a detection sensor using the optical unit 1 or the optical unit 21. The detection sensor 31 constitutes a transmission type detection sensor using two sets of the optical unit 1 or the optical unit 21. The following description is made by taking the optical unit 1 as an example.
[0067]
The direction in which the aperture 12 of the first optical unit 1A faces the condenser lens 17 of the second optical unit 1B, and the direction of the condenser lens 17 of the first optical unit 1A faces the aperture 12 of the second optical unit 1B. Then, the first optical unit 1A and the second optical unit 1B are arranged.
[0068]
As shown in FIG. 7A, when there is no object 25 to be detected, light emitted from the light source 4 of the first optical unit 1A enters the condenser lens 17 of the second optical unit 1B. Enters the photodiode 5 of the second optical unit 1B. Further, light emitted from the light source 4 of the second optical unit 1B is incident on the condenser lens 17 of the first optical unit 1A, thereby being incident on the photodiode 5 of the first optical unit 1A.
[0069]
Thereby, it can be detected from the voltages output from the first optical unit 1A and the second optical unit 1B that there is no object 25 to be detected.
[0070]
As shown in FIG. 7B, when there is an object 25 between the first optical unit 1A and the second optical unit 1B, the light emitted from the light source 4 of the first optical unit 1A is The light is blocked by the detection object 25, does not enter the condenser lens 17 of the second optical unit 1B, and no light enters the photodiode 5 of the second optical unit 1B. Further, the light emitted from the light source 4 of the second optical unit 1B is blocked by the object 25 to be detected and does not enter the condenser lens 17 of the first optical unit 1A. Light does not enter the photodiode 5.
[0071]
Thus, the presence of the detection target 25 can be detected by a change in the voltage output from the first optical unit 1A and the second optical unit 1B.
[0072]
When detecting the presence or absence of the detection target 25, the output of one of the optical units 1 may be monitored. Accordingly, if a configuration is adopted in which a reflection mirror is provided on the opposite surface of the optical unit 1, a configuration equivalent to a transmission type detection sensor can be realized with one optical unit 1.
[0073]
On the other hand, by monitoring the outputs of both optical units 1 using the two optical units 1, the optical unit 1 can be used as a sensor capable of detecting the transport direction of the detection target 25.
[0074]
Here, it is assumed that the object 25 is bidirectionally transported by a mechanism (not shown) in a direction along the direction in which the aperture 12 and the condenser lens 17 are arranged in parallel. When the object 25 is conveyed in the direction of arrow F and the leading end in the conveying direction reaches the position P1, light emitted from the light source 4 of the first optical unit 1A is blocked by the object 25, The light does not enter the condenser lens 17 of the second optical unit 1B, and light does not enter the photodiode 5 of the second optical unit 1B. At this time, the light emitted from the light source 4 of the second optical unit 1B is incident on the condenser lens 17 of the first optical unit 1A, and is incident on the photodiode 5 of the first optical unit 1A.
[0075]
As a result, the output voltage changes between the first optical unit 1A and the second optical unit 1b. Here, as an example, the output when there is the detection object 25 is “L”, and the output when there is no detection object 25 is “H”.
[0076]
That is, when the detection target 25 is transported in the direction of arrow F and reaches the detection position of the detection sensor 31, first, the output of the second optical unit 1B changes from “H” to “L”. When the detected object 25 is further transported in the direction of arrow F and the leading end in the transport direction reaches the position P2, the output of the first optical unit 1A also changes from “H” to “L”. As described above, the change in the voltage output from the first optical unit 1A and the second optical unit 1b can detect the transport direction of the detection target 25. Although not shown, the case where the object 25 is conveyed in the opposite direction can be detected in the same manner.
[0077]
As described above, the optical unit 1 and the optical unit 21 use the optical module 2 having the package 6 in which the light source 4 is mounted on one surface of the die pad 7 and the photodiode 5 is mounted on the other surface. , As a small optical unit. Thus, when used as a detection sensor, there are few restrictions on the installation location in the device, and application to various devices is possible.
[0078]
Also, since the optical housing 3 or the optical housing 22 is attached to the optical module 2, the characteristics of the optical module 2 can be changed without changing the configuration of the optical module 2 by using, for example, the optical housing 3 having different characteristics of the condenser lens 17. Different optical units can be provided. Thereby, optical units having different performances can be provided at low cost.
[0079]
Furthermore, if the light guide 18 is used as the optical housing 3 as in the optical unit 1 of the first embodiment, the number of parts can be reduced, the cost can be reduced, and the size can be further reduced.
[0080]
In addition, since high accuracy is not required for the positional accuracy when attaching the optical housing 3 or the optical housing 22 to the optical module 2, the degree of freedom in design is high, and the size can be reduced.
[0081]
The optical module 2 constituting the optical unit 1 and the optical unit 21 is small and has the first cavity 9 and the second cavity 10 separated by the die pad 7, so that the light of the light source 4 Stray light countermeasures are taken so as not to directly enter the photodiode 5.
[0082]
Thereby, as an example of use of the optical unit 1 or the optical unit 21, not only an optical sensor but also an optical communication device, for example, can be applied. In addition, since the optical module 2 and the optical housing have different configurations, it is conceivable to use the optical module 2 for an optical reader or the like.
[0083]
【The invention's effect】
As described above, according to the present invention, the optical module in which the light from the outside is incident on the light receiving means is attached to the optical module in which the light emitting means and the light receiving means are housed in a single package.
[0084]
In this optical module, a die pad is mounted inside a package to form a first cavity and a second cavity. A light emitting unit is mounted on one surface of the die pad facing the first cavity, and a second cavity is formed. The light receiving means is mounted on the other surface of the die pad facing the cavity. Further, a first opening through which light emitted from the light emitting means passes is provided in the first cavity, and a second opening through which light entering the light receiving means passes is provided in the second cavity. .
[0085]
The optical housing includes a light collecting means for collecting light from the outside, and an optical path changing means for bending a traveling direction of the light collected by the light collecting means toward the light receiving means.
[0086]
Thus, by attaching the optical housing to the optical module having a small package, a small and highly versatile optical unit and optical sensor can be provided.
[0087]
In addition, by setting the detection position of an object on the optical axis of light emitted through the first opening without bending the optical path from the light emitting means, positioning can be easily performed when used as a detection sensor. In addition to this, it can cope with a change in the distance from the object to be detected.
[0088]
Furthermore, since the optical housing provided with the light collecting means and the light path changing means required to make light incident on the light receiving means is attached to the optical module, the mounting accuracy is higher than when the light collecting means and the light path changing means are separately mounted. And when used as a detection sensor, the detection performance can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a configuration example of an optical unit according to a first embodiment.
FIG. 2 is a plan view showing an internal configuration of the optical unit.
FIG. 3 is an external perspective view of the optical unit.
FIG. 4 is a plan view of the optical module.
FIG. 5 is a cross-sectional view illustrating a configuration example of an optical unit according to a second embodiment.
FIG. 6 is an explanatory diagram showing a usage example of the optical unit.
FIG. 7 is an explanatory diagram illustrating a configuration example of a detection sensor using an optical unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Optical unit, 2 ... Optical module, 3 ... Optical housing, 4 ... Light source, 5 ... Photodiode, 6 ... Package, 7 ... Die pad, 9 ... 1st cavity, 10 ... second cavity, 12 ... aperture, 14 ... light emitting lens, 16 ... window, 17 ... condensing lens, 18 ... light guide, 18b: reflection surface, 19: bandpass filter, 21: optical unit, 22: optical housing, 23: reflection mirror, 31: detection sensor

Claims (10)

An optical module containing the light emitting means and the light receiving means in a single package,
An optical housing attached to the optical module, for inputting external light to the light receiving unit,
The optical module,
The package is mounted inside the package to form a first cavity and a second cavity, and the light emitting means is mounted on the side facing the first cavity, and the light emitting means is mounted on the side facing the second cavity. A die pad on which the light receiving means is mounted;
A first opening provided in the first cavity, through which light emitted from the light emitting means passes;
A second opening provided in the second cavity and through which light incident on the light receiving means passes;
The optical housing includes:
Light collecting means for collecting light from the outside,
An optical unit, comprising: an optical path changing unit that bends a traveling direction of the light collected by the light collecting unit toward the light receiving unit. The optical unit according to claim 1, wherein the light collecting unit is provided in parallel with the first opening. The optical unit according to claim 1, wherein the first opening includes a stop unit for stopping light emitted from the light emitting unit. 4. The optical unit according to claim 3, further comprising a light projecting unit between the light emitting unit and the first opening for condensing light emitted from the light emitting unit. The optical unit according to claim 4, wherein the light projecting means is a spherical ball lens. The optical unit according to claim 1, wherein the optical housing includes a bandpass filter that transmits light having a wavelength emitted from the light emitting unit. 7. The optical unit according to claim 6, wherein the light condensing means is a lens, and a layer constituting the bandpass filter is formed on a surface of the light condensing means. 2. The optical unit according to claim 1, wherein the optical housing includes a light guide in which a reflection surface forming the optical path changing unit and a mounting portion of a lens forming the light collecting unit are integrally formed. . The optical unit according to claim 1, wherein the optical path changing unit is a reflection mirror. An optical module containing the light emitting means and the light receiving means in a single package,
An optical housing attached to the optical module, for inputting external light to the light receiving unit,
The optical module,
The package is mounted inside the package to form a first cavity and a second cavity, and the light emitting means is mounted on the side facing the first cavity, and the light emitting means is mounted on the side facing the second cavity. A die pad on which the light receiving means is mounted;
A first opening provided in the first cavity, through which light emitted from the light emitting means passes;
A second opening provided in the second cavity and through which light incident on the light receiving means passes;
The optical housing includes:
Light collecting means for collecting light from the outside,
Light path changing means for bending the traveling direction of the light collected by the light collecting means toward the light receiving means,
An optical sensor, wherein a detection position of an object to be detected is set on an extension of an optical axis passing through the first opening from the light emitting means.

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