Optical link device

An optical link device is provided with an optical communications package including a device positioning member, a photoelectric converter placed on the device positioning member, and leads for connecting contact terminals of the photoelectric converter with an external device; a sealing cap attached to the device positioning member and which seals the photoelectric converter; a condenser lens for guiding incident light to a photo detector (the photoelectric converter) or an optical fiber; a housing in which at least the optical communications package, the condenser lens and the sealing cap are placed; a receptacle for being coupled with the housing as well as the optical connector; a sleeve into which the optical fiber is inserted; a stopper against which the tip of the optical fiber is butted and for positioning the optical fiber. The sealing cap, the condenser lens, and the stopper are formed in a single unit member.

CROSS REFERENCE TO RELATED APPLICATIONS

The present document claims priority to Japanese Priority Document JP 2002-025030, filed in the Japanese Patent Office on Feb. 1, 2002, the entire contents of which are incorporated herein by reference to the extent permitted by law.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an optical link device. More specifically, the present invention relates to an optical link device which performs data communications via an optical fiber by being connected to an optical connector.

2. Description of the Related Art

There are optical devices which perform data communications via an optical fiber by being connected to an optical connector.

An example of a conventional optical link device is described below with reference to FIG.25.

The optical link device a includes a housing b and a receptacle c connected to the housing b.

The housing b has the shape of a box, the inside of which is formed as an internal space d, and includes an opening on one side.

The receptacle c has the shape of a box with an opening on one side and includes a bottom surface e and a side wall f that stands on the circumferential edge of the bottom surface e. A cylindrical sleeve holder section g, which protrudes in the same direction as the side wall f, is provided on the bottom surface e. The circumferential section of the bottom surface e is attached to the edges of the opening of the housing b, and the internal space d of the housing b is closed by the receptacle c.

A cylindrical sleeve h is fitted inside the sleeve holder section g of the receptacle c. The sleeve h may be formed with materials that allow for high precision machining, such as ceramic or metal materials.

A stopper i, placed in the internal space d of the housing b, is attached to the bottom surface e of the receptacle c. The stopper i is formed in the shape of a cylinder that is short in its axial direction and a center aperture is formed as a light transmissive aperture j. The central axis of the sleeve h attached to the inside of the sleeve holder section g of the receptacle c and the central axis of the light transmissive aperture j are in agreement.

A substantially cylindrical holder ring k is attached to the stopper i. A lens holder1is attached to the holder ring k so as to fit therein.

The lens holder1may be formed with a metal material and includes a cylinder section m and a closing section n, which closes an opening on one end of the cylindrical section m. A light transmissive aperture o is formed at a center section of the closing section n. The cylinder section m of the lens holder1is attached to the holder ring K.

A sealing cap p formed with a metal material is placed inside the lens holder1.

An optical communications package q includes a device positioning member r, which is called a stem and is formed with a metal material, leads s, one end of each of which is attached to the device positioning member r, and a photoelectric converter (a photo detector or a light emitting device) t. Contact terminals of the photoelectric converter t are connected to the leads.

The photoelectric converter t is sealed in an airtight manner by having the sealing cap p attached to the device positioning member r. One end of the lens holder1is attached to the device positioning member r such that the lens holder1covers the sealing cap p. By having the photoelectric device t sealed in an airtight manner by the sealing cap p, condensation caused by changes in the surrounding temperature, for example, may be prevented, and the reliability of the operation of the photoelectric device t may be improved.

The sealing cap p and the device positioning member r, as well as the lens holder1and the device positioning member r, are joined together through resistance welding in a nitrogen atmosphere.

A spherical condenser lens u is placed between the lens holder1and the sealing cap p. The condenser lens u is aligned with the light transmissive aperture o of the lens holder1.

Part of the leads s of the optical communications package q protrudes outward from the housing b to connect the contact terminals of the photoelectric converter t with a connector of an external device, such as a personal computer.

An optical connector v to be connected to the optical link device a—includes an optical fiber x supported by a connector section w. The optical fiber x has the tip covered by a ferrule y. A biasing spring z is placed between the connector section w and the ferrule y.

The optical connector v is coupled with the receptacle c by having the connector section w fitted therein. At this point, the ferrule y is inserted and fitted inside the sleeve h. The tip surface of the ferrule y inserted into the sleeve h butts against the stopper i. The biasing spring c presses the ferrule y against the stopper i. As the ferrule y butts against the stopper i, the tip of the optical fiber x is aligned with one end of the light transmissive aperture j of the stopper i.

In order to achieve good optical coupling, it is necessary that the positioning of the photoelectric converter t, the condenser lens u and the optical fiber x be adjusted in the optical link device a—in other words, it is necessary that their axes be aligned. This alignment is accomplished by, for example, adjusting the position of the holder ring k with respect to the stopper i on a surface orthogonal to the optical axis, and by adjusting the position of the lens holder1with respect to the holder ring k along the optical axis. Once the alignment is completed, the holder ring k is secured to the stopper i, and the lens holder1is secured to the holder ring k using, for example, a yttrium aluminum garnet (YAG) laser for instantaneous and firm welding.

When an optical signal is transmitted through the optical fiber x under a condition where the optical connector v is connected to the optical link device a, the transmitted optical signal enters the condenser lens u via the light transmissive aperture j of the stopper i and the light transmissive aperture o of the lens holder1, and is received by the photoelectric converter (the photo detector) t. The optical signal received by the photoelectric converter t is converted into an electrical signal and is input to an external device through the leads s, thereby performing data transmission.

If, on the other hand, the photoelectric converter t of the optical communications package q is a light emitting device, an electrical signal from an external device is input to the photoelectric converter t via the leads s, is converted into an optical signal by the photoelectric converter t, and is emitted towards the condenser lens u. The optical signal that enters the condenser lens u is input to the optical fiber x via the light transmissive aperture o in the lens holder1and the light transmissive aperture j in the stopper i. Data transmission from an external device is thus performed.

The optical link device a described above is designed to either transmit data or receive data. However, there are devices which have both the functions of data transmission and reception as shown in FIG.26.

This optical link device a′ for both transmission and reception includes a pair of sleeve holders g, g, which are spaced apart from each other, provided in a receptacle c′. Inside the sleeve holders g, g are fitted sleeves h, h, respectively. Stoppers i, i are attached to the receptacle c′ so as to be adjacent to each other, and holder rings k, k are attached to the stoppers i, i, respectively. Lens holder1, l are attached to the holder rings k, k, respectively. The lens holder1, l and sealing caps p, p, which are placed inside the lens holder1, l, are attached to one optical communications package q, which functions as a receiver, and another optical communications package q, which functions as a transmitter, respectively.

The optical communications package q that functions as a receiver includes a photo detector as a photoelectric converter t, and the optical communications package q that functions as a transmitter includes a light emitting device as its photoelectric converter t.

An optical connector v′ to be connected to the optical link device a′ includes optical fibers x, x supported by a connector section w. The tips of the optical fibers x, x are covered by ferrules y, y, respectively. Biasing springs z, z are placed between the connector section w and the respective ferrules y, y.

SUMMARY OF THE INVENTION

In the conventional optical link device a, even when variances in the characteristics of the photoelectric converter t or the condenser lens u occur or when errors in the positioning of the photoelectric converter t or the condenser lens u occur, in order to make it possible to carry out assembly in accordance with the characteristics and the positioning of the photoelectric converter t or the condenser lens u, the position of the holder ring k and the lens holder1are adjusted for alignment such that variances and errors in the assembly phase for each component of the optical link device a are eliminated.

However, with the optical link device a, because such alignment procedures are carried out, there lies a problem in that not only is the component count higher, but also in that more work is required in aligning and thereafter securing the various parts.

In addition, in order to make it possible to perform alignment over as wide an area as possible, expensive ceramic and metal materials, which allow for high precision machining and can take complex shapes, need to be used for the various parts, thus resulting in an increase in manufacturing costs.

Furthermore, positioning of the optical fiber x is performed by butting the ferrule y against the stopper i, and there exists between the optical fiber x and the condenser lens a layer of atmosphere having a refractive index that differs significantly from the refractive index of the optical fiber x. Normally, the refractive index of an optical fiber made of quartz is 1.45 times that of the atmosphere. Some of the light that tries to enter the optical fiber x is reflected at the surface of the optical fiber x, and therein lies a danger in that due to the effects of the reflected light, the operation of the photoelectric converter t becomes unstable.

On the other hand, the optical link device a′ includes the optical communications package q that functions as the receiver, and the optical communications package q that functions as the transmitter, thereby aiming to improve the ease of use. However, because the transmitter side and the receiver side are built independently, and because each side includes the stopper i, the holder ring k, the lens holder1, the sealing cap p and the like, there lies a problem in that the component count becomes higher, and in that more work is required in aligning and thereafter securing the various components.

In addition, both the coupling of the sealing cap p and the device positioning member r, as well as the coupling of the lens holder1and the device positioning member r are carried out through welding in both the optical link device a and the optical link device a′. Thus, manufacturing costs become higher because a large scale assembly facility would be required and because materials for the sealing cap p, the lens holder1, and the device positioning member r are limited to expensive metal materials.

The optical link device of the present invention addresses the issues described above by facilitating a more efficient assembly process.

An embodiment of the optical link device of the present invention includes an optical link device to which an optical connector formed such that an optical fiber is supported by a connector section may be connected, the optical link device including: an optical communications package including a device positioning member having prescribed wiring patterns and on which a photoelectric converter, which is either a light emitting device or a photo detector, is placed, as well as leads for connecting contact terminals of the photoelectric converter to an external device; a sealing cap that is attached to the device positioning member of the optical communications package and that seals the photoelectric converter in an airtight manner; a condenser lens that guides incident light to the photo detector or to the optical fiber; a housing in which at least the optical communications package, the condenser lens, and the sealing cap are placed; a receptacle that is coupled with the housing and with which the connector section of the optical connector is coupled; a sleeve into which the optical fiber is inserted when the receptacle and the connector section are coupled; a stopper for positioning the optical fiber by having the tip of the optical fiber inserted into the sleeve butt thereagainst. The sealing cap, the condenser lens, and the stopper are formed as a single unit member. It is to be noted that the following description of the advantages and modifications relate to this embodiment unless otherwise stated.

As a result, the component count can be reduced, while, at the same time, significantly reducing the amount of work required in positioning the photoelectric converter, the condenser lens and the optical fiber, in other words, the work required in the aligning and thereafter securing the various components.

In addition, because of the reduced component count, there is no need to carry out positioning over a wide range, and resin materials may be substituted for ceramic materials or metal materials which allow for high precision machining and which can take complex shapes. As a result, overall manufacturing costs can be reduced.

Furthermore, because the optical fiber is positioned by butting the optical fiber against the stopper of the single unit member, in which the sealing cap, the stopper and the condenser lens are unitized, there does not exist between the optical fiber and the single unit member a layer of atmosphere, the refractive index of which differs significantly from that of the optical fiber. Therefore, light is not reflected at the contacting surface between the optical fiber and the single unit member. Adverse effects of the reflected light on the photoelectric converter are thus minimized, and operation of the photoelectric converter becomes more stable.

Furthermore, by having the sleeve and the receptacle be separate units, a material that would allow for high precision machining may be used for the sleeve, thereby minimizing misalignment of the optical fiber resulting from attaching and detaching the optical connector, and securing good optical coupling characteristics for the optical link device.

In a modification of the embodiment above, an attachment section is provided on the single unit member, and the single unit member is attached to the housing by way of this attachment section. As a result, when the optical connector is coupled with the optical link device, the pressure from the optical fiber would not reach a joint between the single unit member and the optical communications package. Thus, misalignment of the optical communications package with respect to the single unit member as well as detachment therefrom can be prevented.

In another modification of the embodiment above, by having the sleeve holder that holds the sleeve unitized with the receptacle, the component count may be further reduced.

In another modification of the embodiment above, the housing and the receptacle are unitized, and thus the component count may be reduced, while, at the same time, significantly reducing the amount of work involved in aligning and thereafter securing the various parts.

In another modification of the embodiment above, the sleeve and the receptacle are unitized, and thus the component count may be reduced, while, at the same time, significantly reducing the amount of work involved in aligning and thereafter securing the various parts.

In another modification of the embodiment above, the single unit member and the sleeve are unitized, and thus the component count may be reduced, while, at the same time, significantly reducing the amount of work involved in aligning and thereafter securing the various parts.

In another modification of the embodiment above, the single unit member and the device positioning member of the optical communications package are formed using resin materials, and the sealing cap of the single unit member and the device positioning member are fused together. Compared with a case where the single unit member and the optical communications package are welded, fusing does not require as large scale an assembly facility, and enables a significant reduction in manufacturing costs for the optical link device.

In addition, in this case, since expensive metal materials that allow for high precision machining are not used for the single unit member or the optical communications package, a wider choice of materials may be used, and manufacturing costs can be reduced.

Furthermore, by joining the parts through fusing, the strength of fixation can be improved, and an optical link device with better environmental tolerance, especially with respect to temperature and humidity, may be provided.

Because fusing imposes less external stress on the single unit member and the optical communications package during the joining process, the optical characteristics may be expected to be more stable.

In another modification of the embodiment above, the single unit member and the device positioning member of the optical communications package are formed using resin materials, and the sealing cap of the single unit member and the device positioning member are joined together using a hot melt adhesive. Compared with a case where the single unit member and the optical communications package are joined through welding, as large scale an assembly facility is not required, and manufacturing costs for the optical link device can be reduced significantly.

In addition, in this case, since expensive metal materials that allow for high precision machining are not used for the single unit member or the optical communications package, a wider choice of materials are available, and manufacturing costs can be reduced.

Furthermore, by joining the parts through fusing, the strength of fixation can be improved, and an optical link device with better environmental tolerance, especially with respect to humidity and temperature, may be provided.

Because the hot melt adhesive is solid at room temperature, it is easy to handle and provides for better work efficiency.

In another modification of the embodiment above, the joint between the single unit member and the device positioning member of the optical communications package is sealed by a sealing material, thereby further enhancing environmental tolerance, especially with respect to temperature and humidity.

In another modification of the embodiment above, the single unit member and the device positioning member of the optical communications package are each provided with a butting section, and these butting sections are butted against each other, and the sealing cap of the single unit member and the device positioning member are joined at portions other than the butting sections. As a result, the surface of contact where the two butting sections meet each other becomes a surface of reference during joining. Thus, even when the joint is fused, the relative positions of the single unit member and the optical communications package with respect to the axis of the light that is emitted from or enters the photoelectric converter would remain unchanged, and good optical characteristics would thus be ensured.

Another embodiment of the optical link device of the present invention includes an optical link device for being connected with an optical connecter formed such that a pair of optical fibers is supported by a connector section, the optical link device including: an optical communications package that includes a device positioning member having prescribed wiring patterns and on which a photo detector and a light emitting device are placed as photoelectric converters, as well as leads for connecting contact terminals of the photo detector and the light emitting device with an external device; a sealing cap, which is attached to the device positioning member of the optical communications package, for sealing in an airtight manner the photo detector and the light emitting device; a pair of condenser lenses that guide incident light to the photo detector or to the optical fiber; a housing, in which at least the optical communications package, the pair of condenser lenses, and the sealing cap are placed; a receptacle for being coupled with the housing and with the connector section of the optical connector; a pair of sleeves into which the respective optical fibers are inserted when the connector section is coupled with the receptacle; a pair of stoppers, against which the tips of the optical fibers inserted into the respective sleeves are butted, that determine the positions of the pair of optical fibers. The sealing cap, the pair of condenser lenses, and the pair of stoppers are formed into a single unit member. It is to be noted that the following description of the advantages and modifications relate to this embodiment unless otherwise stated.

As a result, the component count is reduced, and the work involved in aligning the photoelectric converters, the condenser lenses, and the optical fibers, as well as in fixing their positions thereafter, is significantly reduced.

Because of the reduced component count, alignment over a wide range is no longer required, and since, as materials for the various parts, resin materials may be substituted for ceramic materials or metal materials that allow for high precision machining and which can take complex shapes, manufacturing costs may be reduced.

Further, because the positions of the optical fibers are determined by being butted against the stopper of the single unit member, in which the sealing cap, the stopper, and the condenser lenses are unitized, there exists between the optical fibers and the single unit member no layer of atmosphere, the refractive index of which is significantly different from that of the optical fibers. Therefore light is not reflected at the butting surface between the optical fibers and the single unit member, and adverse effects caused by reflected light on the photoelectric converters are prevented, thereby providing for more stable operations of the photoelectric converters.

Because the sleeve and the receptacle are formed as separate components, a material that would allow for high precision machining can be used for the sleeve to help reduce misalignment of the axes of the optical fibers upon attachment and detachment of the optical connector. As a result, better optical coupling characteristics are achieved for the optical link device.

In a modification of the embodiment above, an attachment section is formed on the single unit member, and the single unit member is attached to the housing through the attachment section. As a result, when the optical connector is connected to the optical link device, the pressure from the optical fibers does not reach the joint between the single unit member and the optical communications package. As a result, misalignment and detachment of the optical communications package with respect to or from the single unit member may be prevented.

In another modification of the embodiment above, the sleeve holder, which holds the sleeve, is unitized with the receptacle to further reduce the component count.

In another modification of the embodiment above, the housing and the receptacle are unitized, thereby reducing the component count, while, at the same time, significantly reducing the work involved in aligning and thereafter securing the various parts.

In another modification of the embodiment above, the sleeve and the receptacle are unitized, thereby reducing the component count, while, at the same time, significantly reducing the work involved in aligning and thereafter securing the various parts.

In another modification of the embodiment above, the single unit member and the sleeve are unitized to further reduce the component count and to significantly reduce the work involved in aligning and thereafter securing the various parts.

In another modification of the embodiment above, the single unit member and the device positioning member of the optical communications package are formed using resin materials, and the sealing cap of the single unit member and the device positioning member are joined through fusing. As compared to a case where the single unit member and the optical communications package are joined through welding, as large scale an assembly facility is not required, and manufacturing costs for the optical link device may be reduced significantly.

In addition, in this modification, because expensive metal materials that allow for high precision machining are not used for the single unit member or the optical communications package, a wider choice of materials is available, and manufacturing costs are reduced.

Further, because the various parts are joined through fusing, the strength of fixation thereof can be improved, while, at the same time, providing an optical link device with better environmental tolerance, especially with respect to humidity and temperature.

In addition, in this modification, fusing causes less external stress on the single unit member and the optical communications package during the joining, and provides for more stable optical characteristics.

In another modification of the embodiment above, the single unit member and the device positioning member of the optical communications package are formed using resin materials, and the sealing cap of the single unit member and the device positioning member are joined together using a hot melt adhesive. As compared to a case where the single unit member and the optical communications package are joined through welding, as large scale an assembly facility is not required, and manufacturing costs for the optical link device can be reduced significantly.

In addition, in this modification, because expensive metal materials that allow for high precision machining are not used for the single unit member or the optical communications package, a wider choice of materials is available, and manufacturing costs are reduced significantly.

Furthermore, the strength of fixation can be improved, and an optical link device with better environmental tolerance, especially with respect to humidity and temperature, can be provided.

Also, because the hot melt adhesive used in this modification is solid at room temperature, it is easy to handle, and provides for better work efficiency.

In another modification of the embodiment above, the joint between the single unit member and the device positioning member of the optical communications package is sealed using a sealing material, thereby achieving better environmental tolerance, especially with respect to temperature and humidity.

In another modification of the embodiment above, the single unit member and the device positioning member of the optical communications package each include a butting section, and these butting sections butt against each other, and the sealing cap of the single unit member and the device positioning member are joined at parts other than the buffing sections. As a result, a surface of contact, where the two butting sections butt against each other, becomes a surface of reference. Even when the joining parts are fused, the relative positions of the single unit member and the optical communications package with respect to the axis of the light emitted from or entering the photoelectric converter would remain unchanged, and good optical characteristics would thus be ensured.

Another embodiment of the optical link device of the present invention includes an optical link device for being connected to an optical connector formed such that an optical fiber is supported by a connector section, the optical link device including: an optical communications package that includes a device positioning member having prescribed wiring patterns and on which at least one of a light emitting device and a photo detector is placed as a photoelectric converter, as well as leads for connecting contact terminals of the photoelectric converter with an external device; a sealing cap for sealing the photoelectric converter airtight, the sealing cap being attached to the device positioning member of the communications package; a condenser lens that guides incident light to the photo detector or to the optical fiber; a housing in which at least the optical communications package, the condenser lens, and the sealing cap are placed; a receptacle that is connected to the housing and to which the connector section of the optical connector is connected; a sleeve into which the optical fiber is inserted when the receptacle and the connector section are coupled; and a stopper for determining the position of the optical fiber by having the tip of the optical fiber that is inserted in the sleeve butt thereagainst. The sealing cap and the device positioning member of the optical communications package are formed using resin materials and the sealing cap and the device positioning member are joined together through fusing. It is to be noted that the following description of the advantages and modifications relate to this embodiment unless otherwise stated.

Therefore, as compared to a case where the single unit member and the optical communications package are joined through welding, as large scale a facility is not required, and manufacturing costs for the optical link device may be reduced.

Because expensive metal materials that allow for high precision machining are not used for either the single unit member or the optical communications package, a wider choice of material is available, and manufacturing costs are reduced.

Further, by joining the parts through fusing, the strength of fixation thereof can be improved, while, at the same time, providing an optical link device with better environmental tolerance, especially with respect to temperature and humidity.

In addition, fusing imposes less external stress on the joint between the single unit member and the optical communications package, thereby providing for more stable optical characteristics.

In a modification of the embodiment above, the joint between the sealing cap and the device positioning member of the optical communications package is sealed using a sealing material, thereby improving environmental tolerance, especially with respect to temperature and humidity.

In another modification of the embodiment above, the sealing cap and the device positioning member of the optical communications package each include a butting section, and these butting sections are butted against each other. The sealing cap and the device positioning member are joined at parts other than the butting sections. As a result, a surface of contact, where the two butting sections meet, becomes a surface of reference. Even when the joint is fused, the relative positions of the single unit member and the optical communications package with respect to the axis of the light emitted from or entering the photoelectric converter would remain unchanged, and good optical characteristics would thus be ensured.

Another embodiment of the optical link device of the present invention includes an optical link device for being connected to an optical connector formed such that an optical fiber is supported by a connector section, the optical link device including: an optical communications package that includes a device positioning member having prescribed wiring patterns and on which at least one of a light emitting device and a photo detector used as a photoelectric converter is placed, as well as leads for connecting contact terminals of the photoelectric converter with an external device; a sealing cap for sealing the photoelectric converter device airtight and which is attached to the device positioning member of the communications package; a condenser lens that guides incident light to the photo detector or to an optical fiber; a housing in which at least the optical communications package, the condenser lens, and the sealing cap are placed; a receptacle that is connected to the housing and to which the connector section of the optical connector is connected; a sleeve into which the optical fiber is inserted when the receptacle and the connector section are coupled; and a stopper, against which the optical fiber that is inserted into the sleeve is butted, for determining the position of the optical fiber. The sealing cap and the device positioning member of the optical communications package are formed using resin materials, the sealing cap and the device positioning member are joined together using a hot melt adhesive. It is to be noted that the following description of the advantages and modifications relate to this embodiment unless otherwise stated.

Therefore, as compared to a case where the single unit member and the optical communications package are joined through welding, as large scale an assembly facility is not required, and manufacturing costs for the optical link device can be reduced significantly.

Because expensive metal materials that allow for high precision machining are not used for the single unit member or the optical communications package, a wider choice of materials is available, and manufacturing costs can be reduced significantly.

Furthermore, an improvement in the strength of fixation is achieved, and an optical link device having better environmental tolerance, especially with respect to temperature and humidity, is provided.

In addition, because the hot melt adhesive used in this embodiment is solid at room temperature, it is easy to handle and provides for better work efficiency.

In a modification of the embodiment above, the joint between the sealing cap and the device positioning member of the optical communications package is sealed using a sealing material, thereby providing for better environmental tolerance, especially with respect to temperature and humidity.

In another modification of the embodiment above, the sealing cap and the device positioning member of the optical communications package each include a butting section, and the butting sections are butted against each other, and the sealing cap and the device positioning member are joined at parts other than the butting sections. As a result, the surface of contact, where the two butting sections meet each other, becomes a surface of reference. Even when the joint is fused, the relative positions of the single unit member and the optical communications package with respect to the axis of the light emitted from or entering the photoelectric converter would remain unchanged, and good optical characteristics would thus be ensured.

These and further aspects and advantages of the present invention will become clearer in light of the following detailed description of the illustrative embodiments of this invention described in connection with the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the optical link device of the present invention will be described with reference to the appended drawings.

The first embodiment will be described with reference to FIG.1through FIG.13.

An optical link device1includes a housing2. The housing2is formed with a resin material and includes a bottom section3and a circumferential wall section4, which is provided so as to stand at the circumferential edge of the bottom section3, as shown in FIG.1and FIG.2. The housing2includes two separate halves, which are joined together, and an internal space2ais formed therein.

The bottom section3has a plurality of insertion holes3a,3a.

An attachment groove4ais formed on the inner surface of the circumferential wall section4towards the upper part of the circumferential wall section4and extends in the direction of the circumference. A fitting concave section4bis formed at the tip portion of the circumferential wall section4and extends in the direction of the circumference.

A receptacle5is coupled with the housing2. The receptacle5is formed with a resin material and includes a bottom section6and a side wall7provided so as to stand on the circumferential edge of the bottom section6.

A substantially cylindrical sleeve holder8is unitized with the bottom section6and protrudes in the same direction as the side wall7. The sleeve holder8includes a cylindrical circumference surface section8aand an inner flange8b, provided on one end of the circumference surface section8a.

Engagement protrusions7a,7aare provided on the inner surface of the side wall7at the tip portion so as to be spaced apart along the circumference thereof.

The outer circumferential portion of the bottom section6is engaged with the fitting concave section4bof the housing2and the receptacle5is attached thereto. As a result, the receptacle5closes the internal space2aof the housing2.

A cylindrical sleeve9is fitted inside the sleeve holder8of the receptacle5. The sleeve9is formed with a material that allows for high precision machining, such as a ceramic material like zirconium oxide or a metal material like bronze. The inner diameter of the sleeve9is the same size as the inner diameter of the inner flange8bof the sleeve holder8of the receptacle5.

A single unit member10is placed in the internal space2aof the housing2. The single unit member10includes a sealing cap11, a cylindrical stopper12that protrudes from a surface11aon one end of the sealing cap11, a condenser lens13that protrudes from another surface11bon the other side of the sealing cap11, and an attachment section14that protrudes from the side of the sealing cap11and extends in the direction of the circumference, all of which are formed into a single unit and with a transparent resin material. A resin material that has a high transmittance and good environmental tolerance, such as ZEONEX, a product of Zeon Corporation, or ARTON, a product of JSR Corporation, may be used for the single unit member10. The sealing cap11includes a fixing section15that protrudes in the same direction as the condenser lens13from the circumferential edge of the surface11b.

The central axis of the stopper12and the central axis (optical axis) of the condenser lens13are aligned. The tip of the stopper12is formed as a stopper surface12a.

The attachment section14of the single unit member10is engaged with the attachment groove4aof the housing2, and the single unit member10is attached to the housing2. The stopper12of the single unit member10is inserted and fitted inside the sleeve9, and the surface11ais in contact with the bottom section6of the receptacle5.

In addition to the single unit member10, an optical communications package16is placed in the internal space2aof the housing2.

The optical communications package16includes a device positioning member17, which is called a stem and is formed with a resin material, leads18,18, one end of each of which is attached to the device positioning member17, and a photoelectric converter19, which may be a photo detector or a light emitting device. The device positioning member17includes a device positioning section17aand a circumference surface section17bprovided so as to stand on the circumferential edge of the device positioning section17a. Prescribed circuit patterns are formed on the device positioning section17a. The leads18,18are used for connecting contact terminals of the photoelectric converter19to an external device, such as a personal computer, and protrude partially outside the device positioning section17a.

The fixing section15of the single unit member10is fixed to the circumference surface portion17bof the device positioning member17by, for example, fusing. The single unit member10is fixed with the tip surface of the fixing section15butting against the tip surface of the circumference surface section17b, and the photoelectric converter19is sealed in an airtight manner by having the single unit member10fixed to the device positioning member17. By having the photoelectric converter device19sealed in an airtight manner by the single unit member10, condensation due to changes in the surrounding temperature can be prevented, thereby improving the reliability of the operation of the photoelectric converter19.

The optical communications package16is placed in the inner space2ain the housing2with the single unit member10fixed in place. The leads18,18, which protrude outward from the device positioning member17, protrude outside the housing2through the insertion holes3a,3a, respectively, in the bottom section3. As the single unit member10is secured to the optical communications package16, the photoelectric converter19is positioned opposite the condenser lens13of the single unit member10.

An optical connector20to be connected to the optical link device1, includes an optical fiber22supported by a connector section21.

The connector section21includes notches21a,21awhich are formed on one end of the connector section21and are spaced apart in the direction of the circumference. The connector section21also includes a support recess23opened on the other end. The support recess23has an insertion section23ahaving a larger diameter, and a support section23bhaving a smaller diameter.

The tip of the optical fiber22is covered by a ferrule24. Part of the ferrule24is supported by the support section23bof the support recess23so as to be freely slidable, and the tip of the ferrule24protrudes outward from the support recess23. Thus, the optical fiber22is supported by the connector section21via the ferrule24.

A biasing spring25is provided compressed in the support section23bof the support recess23. The biasing spring25biases the ferrule24in a direction such that the ferrule24protrudes from the connector section21.

Steps for assembling the optical link device1will be described below.

First, the single unit member10is fused with and attached to the optical communications package16in, for example, a nitrogen atmosphere. The specific process for fusing will be described later. The positioning of the optical communications package16and the single unit member10, in other words, the photoelectric converter19and the condenser lens13, may be aligned by performing image recognition of the circuit pattern formed on the device positioning member17and taking the recognized image as a reference, or by performing image recognition of light emitted from the photoelectric converter (light emitting device)19and taking the recognized image as a reference.

Next, the optical communications package16and the single unit member10, which have been joined together, are placed inside the housing2. The attachment section14of the single unit member10is engaged with the attachment groove4ain one of the halves of the housing2, while the other half of the housing2is attached to the first half so as to cover the optical communications package16and the single unit member10. The fixing of the attachment section14of the single unit member10to the housing2, and the fixing of the two halves of the housing2are performed by way of, for example, fusing.

Next, the sleeve9is fitted to the stopper12of the single unit member10.

Lastly, the receptacle5is attached to the housing2such that the sleeve holder8covers the sleeve9. The receptacle5is secured to the housing2by engaging the bottom section6of the receptacle5with the fitting concave section4bof the housing2through, for example, fusing. It is assumed herein that when the receptacle5is attached to the housing2, the bottom section6of the receptacle5touches the sealing cap11of the single unit member10.

The connector section21of the optical connector20is engaged with the receptacle5, and the engagement protrusions7a,7aof the receptacle5are engaged with the notches21a,21a, respectively, of the connector section21. At the same time, the ferrule24is inserted into the sleeve9, and the tip surface of the inserted ferrule24butts against the stopper surface12aof the stopper12of the single unit member10. The tip surface of the ferrule24and the tip surface of the optical fiber22are pressed against the stopper surface12aof the stopper12by the biasing spring25. With the ferrule24inserted into the sleeve9, the sleeve holder8of the receptacle5is inserted into the insertion section23aof the connector section21.

Thus, when an optical signal is transmitted through the optical fiber22with the optical connector20coupled with the optical link device1, the transmitted optical signal enters the photoelectric converter (photo detector)19via the stopper12, the sealing cap11, and the condenser lens13of the single unit member10. The optical signal which has thus entered the photoelectric converter19is converted into an electrical signal and is input to an external device via the leads18,18. Thus, data transmission to the external device is performed.

On the other hand, if the photoelectric converter19is a light emitting device, an external device would input an electrical signal to the photoelectric converter19via the leads18,18. The photoelectric converter19converts the electrical signal into an optical signal and emits the optical signal. The emitted optical signal enters the optical fiber22via the condenser lens13, the sealing cap11, and the stopper12of the single unit member10, and thus, data transmission from the external device is carried out.

As described above, because the sealing cap11, the stopper12, and the condenser lens13are formed in a single unit in the single unit member10in the optical link device1, fewer components are required. At the same time, the amount of work required in adjusting the position of the photoelectric converter19, the condenser lens13, and the optical fiber22, in other words, the work required in aligning the various components, and securing them thereafter can be reduced significantly.

In addition, due to the fact that there are fewer components, there is no need to perform positioning over a wide range. Also, as the material for the various components, a resin material may be substituted for ceramic materials and metal materials that allow for high machining precision and which can take complex shapes. Thus, manufacturing costs can be reduced.

Further, because positioning of the optical fiber22is performed by having the ferrule24pressed against the stopper12of the single unit member10, in which the sealing cap11, the stopper12, and the condenser lens13are formed in a single unit, there exists no layer of atmosphere having a refractive index that is significantly different from that of the optical fiber22between the optical fiber22and the single unit member10. For this reason, light is not reflected at the surface where the ferrule24and the single unit member10meet, and adverse effects of reflected light on the photoelectric converter device19are prevented. As a result, the operation of the photoelectric converter19can be stabilized.

Furthermore, because the sleeve9and the receptacle5are provided as separate components, a material that would allow for high precision machining may be used for the sleeve9to reduce the likelihood of misalignment of the ferrule24resulting from attaching and detaching the optical connector20, and good optical coupling characteristics can be secured for the optical link device1.

In addition, because the receptacle5and the sleeve holder8are formed in a single unit, a further reduction in the component count can be achieved.

Further, because the attachment section14is provided on the single unit member10, and the single unit member10, which is joined to the optical communications package16by way of the attachment section14, is attached to the housing2, the pressure from the ferrule24at the time of coupling the optical connector20with the optical link device1is not carried to the joint between the single unit member10and the optical communications package16, and thus, the optical communications package16may be prevented from becoming misaligned with respect to or detached from the single unit member10.

Below, a method of joining the single unit member10and the optical communications package16will be described with reference to FIG.3through FIG.13.

Firstly, joining the single unit member10and the optical communications package16through fusing will be described with reference to FIG.3through FIG.6.

A flat plate shaped heat iron26is placed between the single unit member10and the optical communications package16, as shown in FIG.3. The single unit member10and the optical communications package16are placed in contact with or close to the heat iron26, and a joint10aand a joint17cof the single unit member10and the device positioning member17of the optical communications package16, respectively, are melted as shown in FIG.4. Then, the single unit member10and the optical communications package16are temporarily pulled apart, and the heat iron26is pulled out, as shown in FIG.5. Finally, the joints10aand17care placed in contact with each other to join the single unit member10and the optical communications package16, as shown in FIG.6.

In order to secure superior airtightness, the steps described above are performed in a nitrogen atmosphere.

Alternatively, the following method of joining through fusing may also be adopted, as shown in FIG.7andFIG. 8Firstly, the joints10aand17cof the single unit member10and the device positioning member17of the optical communications package16, respectively, are placed in contact with each other, and heat irons27,27are brought closer to the joints10aand17cfrom the sides in order to fuse and join them, as shown in FIG.7. Once the joints10aand17care fused and the joining of the joints10aand17cis completed, the heat irons27,27are pulled away from the joints10aand17c, respectively, as shown in FIG.8.

While in FIG.3throughFIG. 8, methods of joining through fusing using the heat iron26or the heat irons27,27are illustrated, the single unit member10and the optical communications package16may also be joined together by melting the joints10aand17cusing hot air, high frequency induction heating, light irradiation, ultrasound, or a melting agent.

By thus joining the single unit member10and the optical communications package16through fusing, as compared to a case where the single unit member10and the optical communications package16are joined through welding, as large scale an assembly facility is not required, and manufacturing costs of the optical link device1may be reduced significantly.

In addition, because high cost metal materials that allow for high precision machining are not used for the single unit member10or the optical communications package16, a wider choice of materials is available, thus providing for reduced manufacturing costs.

Furthermore, by joining the single unit member10and the optical communications package16through fusing, the strength of fixation can be improved, while, at the same time, providing an optical link device1having better environmental tolerance, especially with respect to humidity and temperature.

In addition, fusing imposes less external stress on the single unit member10and the optical communications package16at the time of joining, and helps stabilize the optical characteristics.

It is preferable, however, that the same material be used for both the single unit member10and the optical communications package16in order to enhance the strength of fixation.

FIG. 9shows an example where the single unit member10and the optical communications package16are joined and the joint is sealed using a sealing material28. By thus sealing the joint with the sealing material28, the environmental tolerance of the device can further be improved, especially with respect to humidity and temperature.

FIG. 10shows an example where butting sections10band17dthat are provided on the single unit member10and the device positioning member17of the optical communications package16, respectively, at positions that are different from the positions of the joints10aand17cfor joining the single unit member10and the optical communications package16. The butting section10bof the single unit member10is provided further inward than the joint10a, and the butting section17dof the device positioning member17is provided further inward than the joint17c.

The single unit member10and the optical communications package16are joined together with the butting section10band the butting section17dbutting against each other. Therefore, a surface of contact where the butting section10band the buffing section17dbutt against each other becomes a surface of reference, and even when the joints10aand17care fused, the relative positions of the single unit member10and the optical communications package16with respect to the axis of the light that is emitted from or enters the photoelectric converter19remain unchanged, thereby securing better optical characteristics.

Next, a method of joining the single unit member10and the optical communications package16using a hot melt adhesive will be described with reference to FIG.11through FIG.13.

A hot melt adhesive is a thermoplastic resin adhesive that is solid at room temperature and melts when heated.

The hot melt adhesive29is applied on the joint17cof the optical communications package16, as shown in FIG.11. Then, the joint10aof the single unit member10is placed in contact with the joint17cof the optical communications package16with the hot melt adhesive29in between, and the hot irons27,27are brought closer to the joints10aand17cto melt the hot melt adhesive29, as shown in FIG.12. Once the hot melt adhesive29is melted, the heat irons27,27are pulled away from the joints10aand17cto cool the hot melt adhesive29, and the single unit member10and the optical communications package16are thus joined, as shown in FIG.13.

By using the hot melt adhesive29in joining the single unit member10and the optical communications package16, the strength of fixation can be improved, while, at the same time, providing an optical link device1having superior environmental tolerance, especially with respect to humidity and temperature.

Because the hot melt adhesive29is solid at room temperature, it is easy to handle, thus providing for higher efficiency.

As in the previous example, in the case described above where the single unit member10and the optical communications package16are joined using the hot melt adhesive, the joint may be sealed with the sealing material28, and the butting sections10band17dmay also be provided and used in joining.

In FIG.3throughFIG. 13, examples where the single unit member10and the optical communications package16are joined together through fusing or by using the hot melt adhesive29are shown. However, even in a case where the sealing cap is formed separate from the condenser lens and the like, it is possible to join the sealing cap and the optical communications package16through fusing or by using the hot melt adhesive29.

Next, the second embodiment will be described with reference to FIG.14.

An optical link device1A of the second embodiment described below differs from the optical link device1described earlier only in that the housing and the receptacle are formed in a single unit, and the receptacle and the sleeve holder are formed as separate units. For this reason, only the parts that differ from the optical link device1will be described in detail. Other parts will be assigned the same or similar reference numerals as those assigned to the corresponding parts in the optical link device1and description thereof will be omitted.

The optical link device1A includes a housing2A and a receptacle5A which are unitized into a body30and formed using a resin material, and the body30includes a bottom section31, a circumferential wall section32that is provided so as to stand on the circumferential edge of the bottom section31, and a closing section33that protrudes inward from the circumferential wall section32around halfway up the circumferential wall section32. The body30includes two separate halves that are joined together. A sleeve insertion hole33ais opened in a center portion of the closing section33.

A sleeve holder34is inserted and positioned in the sleeve insertion hole33a. The sleeve holder34includes a cylindrical circumference surface section34a, an inner flange34bprovided on one end of the circumference surface section34a, and an outer flange34cprovided on the other end of the circumference surface section34a. The sleeve holder is positioned by inserting the circumference surface section34ainside the sleeve insertion hole33a, and the outer flange34cis positioned such that it is held between the sealing cap11of the single unit member10and the closing section33of the body30.

A sleeve9is fitted inside the circumference surface section34aof the sleeve holder34.

As mentioned above, because the housing2A and the receptacle5A of the optical link device1A are unitized as the body30, the component count can be reduced, and the work involved in aligning and thereafter securing the various components can be reduced significantly.

A modification of the second embodiment will be described next with reference to FIG.15.

This modification, an optical link device1B, includes a housing2B, a receptacle5B, and a sleeve holder8B, which are formed with a resin material and which are unitized as a body35. As a result, a further reduction in component count is made possible.

Next, a third embodiment will be described with reference to FIG.16.

An optical link device1C of the third embodiment differs from the optical link device1described earlier only in that the receptacle and the sleeve are formed in a single unit. Therefore, only the parts that differ from the optical link device1will be described in detail, while the other parts will be assigned the same reference numerals as those assigned to comparable parts of the optical link device1, and description thereof will be omitted.

The optical link device1C includes a receptacle5C and a sleeve9C that are formed with a resin material and are unitized into a sleeve integrated receptacle36. For this reason, the optical link device1C does not include a sleeve holder.

The inner diameter of the sleeve9C is formed so as to be equal to the outer diameter of the stopper12of the single unit member10, and the stopper12is fitted inside the sleeve9C.

As mentioned above, because the receptacle5C and the sleeve9C are unitized in the sleeve integrated receptacle36in the optical link device1C, the component count can be reduced, while, at the same time, reducing the work involved in aligning and thereafter securing the various parts.

Next, a fourth embodiment will be described with reference to FIG.17.

An optical link device1D of the fourth embodiment described below differs from the optical link device1described earlier only in that the sealing cap, the stopper, the condenser lens, and the sleeve are formed in a single unit, and in that the receptacle does not include the sleeve holder. Therefore, only the parts that differ from the optical link device1will be described in detail, while the other parts will be assigned the same reference numerals as those assigned to comparable parts in the optical link device1, and description thereof will be omitted.

The optical link device1D includes a sealing cap11D, a stopper12D, a condenser lens13D, a sleeve9D, and an attachment section14D, all of which are unitized as a single unit member10D. The sleeve9D extends from the stopper12D. A fixing section15D is provided on the sealing cap11D.

The receptacle5D includes a bottom section6D and a side wall7D provided so as to stand on the circumferential edge of the bottom section6D. An insertion hole6ais opened at a center portion of the bottom section6D. The sleeve9D of the single unit member10D is inserted and positioned in the sleeve insertion hole6a. Therefore, the optical link device1D does not include a sleeve holder.

As described above, in the optical link device1D, because the sealing cap11D, the stopper12D, the condenser lens13D, and the sleeve9D are unitized in the single unit member10D in the optical link device1D, the component count can be reduced, and the work involved in aligning and thereafter securing the various parts can be reduced significantly.

A variation of the fourth embodiment will be described next with reference to FIG.18.

In an optical link device1E of this variation, a housing2E and a receptacle5E are formed with a resin material and are unitized as a body37. Therefore, a further reduction in component count is possible.

A fifth embodiment will be described next with reference to FIG.19.

An optical link device1F of the fifth embodiment is one in which the functions of the optical link device1of the first embodiment are expanded, and functions both as a receiver and a transmitter.

The optical link device1F includes a housing38, which is formed with a resin material and includes a bottom section39and a circumferential wall section40provided so as to stand on the circumferential edge of the bottom section39. The housing38includes two separate halves that are joined together and the interior is formed as an internal space38a.

A plurality of insertion holes39a,39a. . . are formed on the bottom section39.

An attachment groove40ais formed towards the tip of the inner side of the circumferential wall section40and extends in the direction of the circumference. A fitting concave section40bis formed at the tip portion of the circumferential wall section40and extends in the direction of the circumference.

A receptacle41is coupled with the housing38. The receptacle41is formed with a resin material and includes a bottom section42and a side wall43provided so as to stand on the circumferential edge of the bottom section42.

Cylindrical sleeve holders44,44, which protrude from the bottom section42in the same direction as the side wall43, are provided as part of the bottom section42but are spaced apart from each other. The sleeve holders44,44each include a cylindrical circumference surface section44a, and an inner flange44bprovided on one end of the circumference surface section44a.

Engagement protrusions43a,43aare formed on the inner side of the tip portion of the side wall43such that they are spaced apart along the circumferential direction.

The outer circumference portion of the bottom section42of the receptacle41is fitted with the fitting concave section40bof the housing38, and the receptacle41closes the internal space38aof the housing38.

Cylindrical sleeves45,45are fitted inside the sleeve holders44,44, respectively, of the receptacle41. The sleeves45,45are formed using a material that would allow for high precision machining, including, for example, a ceramic material, such as zirconium oxide and the like, or a metal material, such as phosphor bronze and the like. The inner diameter of the sleeves45,45is made the same as the inner diameter of the flanges44b,44bof the sleeve holders44,44of the receptacle41.

A single unit member46is placed in the internal space38ain the housing38. The single unit member46includes a sealing cap47; cylindrical stoppers48,48that protrude from a surface47aon one end of the sealing cap47and which are spaced apart from each other; condenser lenses49,49that protrude from a surface47bon the other end of the sealing cap47and which are spaced apart from each other; and an attachment section50that protrudes from a side surface of the sealing cap47and extends in the direction of the circumference, all of which are formed with a transparent resin material and as a single unit. Materials such as ZEONEX and ARTON may be used for the single unit member46. The sealing cap47includes a fixing section51that protrudes from the circumferential edge of the surface47bin the same direction as the condenser lenses49,49.

The central axes of the stoppers48,48and the central axes of the condenser lenses49,49, respectively, are aligned. The tip surfaces of the stoppers48,48are formed as stopper surfaces48a,48a.

The single unit member46is attached to the housing38by having the attachment section50of the single unit member46fitted with the attachment groove40aof the housing38. The stoppers48,48of the single unit member46are inserted and fitted into the sleeves45,45, and the surface47ais in contact with the bottom section42of the receptacle41.

In addition to the single unit member46, an optical communications package52is also placed in the internal space38ain the housing38.

The optical communications package52includes a device positioning member53, which is called a stem and is formed with a resin material; leads54,54. . . , one end of each of which is attached to the device positioning member53; and a light emitting device and a photo detector provided as photoelectric converters55,55. The device positioning member53includes a device positioning section53aand a circumference surface section53bprovided so as to stand on the circumferential edge of the device positioning section53a, which are provided as a single unit. A prescribed circuit pattern is formed on the device positioning section53a. The leads54,54, . . . are used for connecting contact terminals of the photoelectric converters55,55with an external device, such as a personal computer or the like, and therefore part of each of the leads54,54, . . . protrudes outside of the device positioning section53a.

The fixing section51of the single unit member46is fixed to the circumference surface section53bof the device positioning member53through fusing or through adhesion using a hot melt adhesive. The single unit member46is fixed in place with the tip surface of the fixing section51butting against the tip surface of the circumference surface section53b. By thus having the single unit member46fixed to the device positioning member53, the photoelectric converters55,55are sealed in an airtight manner. By having the photoelectric converters55,55sealed airtight with the single unit member46, condensation due to, for example, changes in the surrounding temperature may be prevented, thereby improving the reliability of the operation of the photoelectric converters55,55.

The optical communications package52, with the single unit member46secured thereon, is placed in the internal space38ain the housing38, and the leads54,54, . . . that protrude outward from the device positioning member53are passed through the respective insertion holes39a,39a, . . . in the bottom section39of the housing38so as to protrude externally. With the single unit member46secured onto the optical communications package52, the photoelectric converters55,55are positioned such that they are opposite the respective condenser lenses49,49of the single unit member46.

The optical connector56to be connected to the optical link device1F includes optical fibers58,58, which are supported by a connector section57.

Notches57a,57aare formed on one end of the connector section57so as to be spaced apart along the direction of the circumference. Supportive recesses59,59are formed in the connector section57and in isolation from each other. The supportive recesses59,59include insertion sections59a,59a, respectively, of a larger diameter, and support sections59b,59b, respectively, of a smaller diameter.

The tips of the optical fibers58,58are covered with ferrules60,60, respectively. For each of the ferrules60,60, a part thereof is supported by the support section59bof the supportive recess59so as to be freely slidable. The tips of the ferrules60,60protrude from the supportive recesses59,59. Thus, the optical fibers58,58are supported by the connector section57by way of the respective ferrules60,60.

Basing springs61are stored compressed in each of the support sections59b,59bof the supportive recesses59,59, respectively. The biasing spring61,61bias the ferrules60,60, respectively, outward from the connector section57.

Steps for assembling the optical link device1F will be described next.

Firstly, the single unit member46is attached to the optical communications package52in a nitrogen atmosphere by fusing or by adhesion using a hot melt adhesive. The procedures for fusing or for adhesion with a hot melt adhesive are similar to the procedures for the optical link device1of the first embodiment shown in FIG.3through FIG.13.

The positioning of the optical communications package52and the single unit member46, in other words, the photoelectric converters55,55and the respective condenser lenses49,49, may be aligned by performing image recognition of the circuit pattern formed on the device positioning member53and using the recognized image as a reference, or by having the photoelectric converter55(the light emitting device) emit light, performing image recognition of the point of emission, and using the recognized image as a reference.

Next, the optical communications package52and the single unit member46, which have been joined together, are placed inside the housing38. The attachment section50of the single unit member46is fitted with the attachment groove40ain one of the halves of the housing38, and the other half of the housing38is attached to the first half so as to cover the optical communications package52and the single unit member46. The securing of the attachment section50of the single unit member46to the housing38and the securing of the two halves of the housing38may be performed through, for example, adhesion.

Next, the sleeves45,45are fitted with the respective stoppers48,48of the single unit member46.

Lastly, the receptacle41is attached to the housing38with the sleeve holders44,44such that they cover the respective sleeves45,45. The receptacle41is secured onto the housing38by fitting the bottom section42of the receptacle41with the fitting concave section40bof the housing38, and then performing, for example, adhesion. When the receptacle41is attached to the housing38, the bottom section42of the receptacle41comes in contact with the sealing cap47of the single unit member46.

The optical connector56is coupled with the receptacle41by fitting the connector section57into the receptacle41and by engaging the engagement protrusions43a,43aof the receptacle41with the respective notches57a,57aof the connector section57. At the same time, each of the ferrules60,60is inserted into the corresponding sleeve45and the tip surface of each of the inserted ferrules60,60butts against the stopper surface48aof the corresponding stopper48of the single unit member46. The biasing springs61,61press the tip surfaces of the ferrules60,60and the tip surfaces of the optical fibers58,58against the respective stopper surfaces48a,48aof the stoppers48,48. As the ferrules60,60are inserted into the respective sleeves45,45, the sleeve holders44,44of the receptacle41are also inserted into the respective insertion sections59a,59aof the connector section57.

With the optical connector56and the optical link device1F thus coupled, when an optical signal is transmitted through one of the optical fibers58,58, the transmitted optical signal passes through the respective stopper48, the sealing cap47, and the condenser lens49of the single unit member46, and enters the photoelectric converter55(photo detector). The optical signal entering the photoelectric converter55is converted into an electrical signal, which is in turn input to an external device via the leads54,54, and thus data transmission with the external device is performed.

On the other hand, when an electrical signal is input from an external device via the leads54,54to the photoelectric converter55(light emitting device), the photoelectric converter55converts the electrical signal into an optical signal and emits the optical signal from the photoelectric converter55. The emitted optical signal enters the optical fiber58via the respective condenser lens49, the sealing cap47, and the stopper48of the single unit member46, and data transmission from the external device is thus performed.

As mentioned above, the sealing cap47, the pair of stoppers48,48, and the pair of condenser lenses49,49are all unitized into the single unit member46in the optical link device1F, and the section that functions as the receiver and the section that functions as the transmitter are not divided into separate structures. For this reason, the component count can be reduced, and the work involved in positioning the photoelectric converters55,55, the condenser lenses49,49, and the optical fibers58,58, in other words, the work involved in aligning and thereafter securing the various parts can be reduced significantly.

In addition, due to the reduced component count, an alignment across wide ranges is not necessary, and for the various parts, resin materials may be substituted for ceramic materials or metal materials that allow for high precision machining and which can take complex shapes. As a result, manufacturing costs can be reduced.

Furthermore, because positioning of the optical fibers58,58is performed by butting the ferrules60,60against the respective stoppers48,48of the single unit member46, in which the sealing cap47, the stoppers48,48, and the condenser lenses49,49are formed in a single unit, there exists no layer of atmosphere, the index of refraction of which would be significantly different from that of the optical fibers58,58, between the optical fibers58,58and the single unit member46. Therefore light is not reflected at the surface where the ferrules60,60are butted against the single unit member46, thereby preventing adverse effects of reflected light on the photoelectric converters55,55, and stabilizing the operation of the photoelectric converters55,55.

Furthermore, the sleeves45,45are separate from the receptacle41, and a material that would allow for high precision machining may be used for the sleeves45,45, thereby minimizing misalignment of the ferrules60,60that could result from attaching and detaching the optical connector56. As a result, good optical coupling characteristics of the optical link device1F can be maintained.

Since the receptacle41and the sleeve holders44,44are formed in a single unit, the component count may further be reduced.

In addition, because the attachment section50is provided on the single unit member46, and the single unit member46joined with the optical communications package52is attached to the housing38by way of the attachment section50, the pressure from the ferrules60,60at the time of coupling the optical connector56with the optical link device1F is not carried to the joint between the single unit member46and the optical communications package52. Therefore, the optical communications package52can be prevented from becoming out of alignment with respect to the single unit member46or from becoming detached altogether.

Next, a sixth embodiment will be described with reference to FIG.20.

The optical link device1G of the sixth embodiment differs from the optical link device1F of the fifth embodiment described above only in that the housing and the receptacle are formed into a single unit, and in that the receptacle and the sleeve holder are separate units. Therefore, only the parts that differ from the optical link device1F will be described in detail, while the other parts will be assigned the same reference numerals as the comparable parts in the optical link device1F and description thereof will be omitted.

The optical link device1G of the sixth embodiment is one in which the functions of the optical link device1A of the second embodiment are extended, and is equipped with the functions of both a receiver and a transmitter.

In the optical link device1G, a housing38G and a receptacle41G are formed with a resin material and are unitized as a body62. The body62includes a bottom section63, a circumferential wall section64provided so as to stand on the circumferential edge of the bottom section63, and a closing section65that protrudes inward from the circumferential wall section64around the middle thereof with respect to the axial direction. The container62includes two separate halves that are joined together. The closing section65includes sleeve insertion holes65a,65a, which are spaced apart from each other.

A sleeve holder66is inserted and placed inside each of the sleeve insertion holes65a,65a. The sleeve holder66includes a flat base section66aand holders66b,66b, which protrude from the base section66abut are formed apart from each other. The base section66aand the holders66b,66bare formed in a single unit. Each of the holders66b,66bincludes a cylindrical circumference surface section66cand an inner flange66dprovided on one end of the circumference surface section66c. The holders66b,66bare inserted into the respective sleeve insertion holes65a,65aso as to position the sleeve holder66, while the base section66aof the sleeve holder66is held between the sealing cap47of the single unit member46and the closing section65of the body62.

Sleeves67,67are fitted inside the circumference surface sections66c,66cof the sleeve holder66.

As described above, the housing38G and the receptacle41G are unitized as the body62in the optical link device1G. As a result, the component count can be reduced, and the work involved in aligning and thereafter securing the various parts can be reduced significantly.

A modification of the sixth embodiment will be described next with reference to FIG.21.

In an optical link device1H of the modification, a housing,38H, a receptacle41H, and sleeve holders44H,44H, are formed with a resin material and are unitized as a body68. For this reason, a further reduction in component count is possible.

A seventh embodiment will be described next with reference to FIG.22.

An optical link device1I of the seventh embodiment differs from the optical link device1F of the fifth embodiment only in that the receptacle and the sleeve are formed in a single unit. Therefore, only the parts that differ from the optical link device1F will be described in detail, while the other parts will be assigned the same reference numerals as those of the corresponding parts in the optical link device1F and description thereof will herein be omitted.

The optical link device1I of the seventh embodiment is one in which the features of the optical link device1C of the third embodiment are expanded, and is equipped with functions of both a receiver and a transmitter.

In the optical link device1I, a receptacle41I and sleeves45I,45I are formed with a resin material and are unitized as a sleeve-integrated receptacle69. For this reason, the optical link device1I does not include a sleeve holder.

The inner diameters of the sleeves45I,45I are the same as the outer diameters of the stoppers48,48of the single unit member46, and the stoppers48,48are fitted inside the sleeves45I,45I.

As described above, the receptacle41I and the sleeves45I,45I are unitized as the sleeve-integrated receptacle69in the optical link device1I. As a result, the component count can be reduced, and the work involved in aligning and thereafter securing the various parts can be reduced significantly.

An eighth embodiment will be described next with reference to FIG.23.

An optical link device1J of the eighth embodiment differs from the optical link device1F of the fifth embodiment only in that the sealing cap, the stoppers, the condenser lenses, and the sleeves are formed in a single unit, and in that the receptacle does not include a sleeve holder. Only the parts that differ from the optical link device1F will be described in detail, while the other parts will be assigned the same reference numerals as the corresponding parts in the optical link device1F and description thereof will herein be omitted.

In the optical link device1J, a sealing cap47J, stoppers48J,48J, condenser lenses49J,49J, sleeves45J,45J, and an attachment section50J are unitized as a single unit member46J, and the sleeves45J,45J are formed as part of the stoppers48J,48J. A fixing section51J is formed on the sealing cap47J.

The receptacle41J includes a bottom section42J and a side wall43J provided so as to stand on the circumferential edge of the bottom section42J. Sleeve insertion holes42a,42aare formed at a center portion of the bottom section42J. The sleeves45J,45J of the single unit member46J are inserted and positioned inside the sleeve insertion holes42a,42a. As such, the optical link device1J does not include a sleeve holder.

Because the sealing cap47J, the stoppers48J,48J, the condenser lenses49J,49J, and the sleeves45J,45J, are unitized as the single unit member46J in the optical link device1J, the component count can be reduced, and the work involved in aligning and thereafter securing the various parts can also be significantly reduced.

A modification of the eighth embodiment will be described next with reference to FIG.24.

An optical link device1K of this modification includes a housing38K and a receptacle41K, which are formed with a resin material and are unitized as a body70. Therefore, a further reduction in component count is possible.

It is to be noted that in the optical link devices1G,1H,1I,1J, and1K described above, the attachment of the communications package to the single unit member may be performed through fusing or adhesion using a hot melt adhesive, as shown in FIG.3through FIG.13.

The shapes and structures of the various parts described in the embodiments above only represent a few examples for practicing the present invention, and thus, since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalents of the claims are intended to be embraced therein.