JP5135804B2 - Film optical waveguide, film optical waveguide module, and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film optical waveguide that makes stable optical transmission possible even if used in a bent state. <P>SOLUTION: A core part 11 is structured such that, in the cross section vertical to the extending direction (Z direction) of the optical waveguide 4, the center position of the core part 11 is set deviated from the center position of the optical waveguide 4. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a film optical waveguide that transmits an optical signal, a film optical waveguide module, and an electronic apparatus.

  In recent years, optical communication networks capable of high-speed and large-capacity data communication have been expanded. In the future, this optical communication network is expected to be installed between devices. And the printed wiring board is expected to be optical wiring.

  The optical waveguide has a double structure of a core called a core and a sheath called a clad covering the core, and the refractive index of the core is higher than that of the clad. That is, the optical signal incident on the core is propagated by repeating total reflection inside the core.

  Further, particularly in recent years, it has been required to realize a printed wiring board and electrical wiring mounted on a smaller and thinner consumer device with an optical waveguide. On the other hand, an optical waveguide having high flexibility has been developed by using a material that is more flexible than conventional materials for the core and cladding of the optical waveguide. If such an optical waveguide having high flexibility is used, data transmission between substrates in the device can be performed using the optical waveguide.

Here, a mechanism of optical transmission in an optical waveguide module using an optical waveguide will be briefly described. First, based on an electrical signal input from the outside, the drive unit drives the light emission of the light emitting unit (optical element), and the light emitting unit irradiates the light incident surface of the optical waveguide with light. The light applied to the light incident surface of the optical waveguide is introduced into the optical waveguide and is emitted from the light output surface of the optical waveguide. And the light radiate | emitted from the light-projection surface of an optical waveguide is received by the light-receiving part (optical element), and is converted into an electrical signal.
JP 2000-214351 A (released on August 4, 2000) JP 2000-9968 (released on January 14, 2000) JP 2000-292656 A (released on October 20, 2000) JP-A-2005-331535 (released on December 2, 2005)

  However, in the above-described conventional configuration, for example, when the film optical waveguide is bent in a direction twisting with respect to the light transmission direction, the core portion passes through the portion that allows the most bending, that is, the portion with the largest amount of deformation. . Further, when the film optical waveguide is bent in a direction perpendicular to the light transmission direction, the radius of curvature of the portion where the deformation amount is largest in the core portion is the radius of curvature of the portion where the deformation amount is largest in the optical waveguide. Will be equal. For this reason, when the optical waveguide is used in a bent state, the bending loss due to loss fluctuation when bent is increased. Thus, in the configuration of the conventional optical waveguide, stable optical transmission is difficult due to the influence of bending loss.

  Moreover, the following problems arise in the optical waveguide module using the optical waveguide. As described above, in order to perform optical transmission, the distance between the light emitting portion and the light incident surface of the optical waveguide and the distance between the light receiving portion and the light emitting surface of the optical waveguide are kept constant. Need to be combined. Conventionally, many techniques for optically coupling the optical waveguide and the optical element have been proposed, and disclosed in, for example, Patent Documents 1 to 3 and the like.

  In Patent Document 1, a bump is interposed between an optical element and an optical waveguide to align the optical element and the optical waveguide by filling an air gap between the optical element and the optical waveguide. I am letting. In Patent Document 2, the optical element and the optical fiber are optically coupled by aligning the tip of the optical fiber on the optical element and fixing them with an adhesive. In Patent Document 3, an optical element and an optical waveguide are optically coupled by fixing the optical waveguide on a substrate having a recess for receiving the optical element.

  However, when an optical waveguide is used in a small and thin device, the entire optical waveguide module including the optical waveguide must be downsized. On the other hand, in the above-described conventional configuration, the optical waveguide is held by an adhesive or a substrate around the optical element, so that there is a problem that more electrical wiring space is required to connect to the optical element. Have. When such a space increases, it becomes difficult to mount the optical waveguide module on a small and thin device.

  Therefore, for example, Patent Document 4 discloses an optical coupling device that realizes space saving of electrical wiring.

  However, in the configuration of Patent Document 4, the area for holding the end portion of the optical waveguide must be reduced in order to secure a space for connecting the electrical wiring to the optical element. For this reason, it is difficult to reliably hold the end portion of the optical waveguide, and in the case of a flexible optical waveguide, it is easily deformed due to the influence of vibration and heat. When such an end portion of the optical waveguide is deformed, a coupling loss occurs when light is irradiated from the light source to the optical waveguide, which causes a problem that stable optical transmission becomes difficult.

  As described above, the conventional configuration has not realized what can achieve stable optical transmission and downsizing of the optical waveguide module.

  The present invention has been made in view of the above problems, and one of its purposes is to provide a film optical waveguide capable of stable light transmission even when used in a bent state. .

  A second object of the present invention is to provide a film optical waveguide module and an electronic apparatus that can stably transmit light even when used in a bent state and can be downsized.

  In order to solve the above problems, a film optical waveguide according to the present invention includes a core portion made of a light-transmitting material and a clad made of a material having a refractive index different from the refractive index of the core portion. And the core portion has a cross-section perpendicular to the extending direction of the film optical waveguide, the center position of the core portion is shifted from the center position of the film optical waveguide. It is the structure provided.

  According to said structure, the said core part is provided in the cross section of the direction perpendicular | vertical to the extension direction of the said film optical waveguide, and the center position of the said core part has shifted | deviated from the center position of the said film optical waveguide. . That is, the central axis in the extending direction of the core portion is shifted from the central axis in the extending direction of the film optical waveguide.

  Conventionally, the core portion is provided so that the central axis of the core portion coincides with the central axis of the optical waveguide in the extending direction. Therefore, for example, when the film optical waveguide is bent in a direction twisting with respect to the extending direction, the core portion passes through the portion with the largest deformation amount.

  On the other hand, in said structure, the core part is a structure by which the center axis | shaft of the said extension direction in a core part has shifted | deviated from the center axis | shaft of the extension direction of a film optical waveguide. Thereby, for example, when the film optical waveguide is bent in a direction twisted with respect to the extending direction, the core portion avoids the portion having the largest deformation amount. Therefore, in the above configuration, it is possible to reduce bending loss due to loss variation when bent compared to the conventional configuration. Therefore, according to said structure, even when a film optical waveguide is used in the state bent, the film optical waveguide which can perform the stable optical transmission can be provided.

  In order to solve the above problems, a film optical waveguide according to the present invention is composed of a core portion made of a light-transmitting material and a material having a refractive index different from the refractive index of the core portion. A film optical waveguide provided with a cladding portion, wherein the core portion is provided such that a center position of the core portion is shifted from a center position of the film optical waveguide at an end surface of the film optical waveguide. In this configuration, the film optical waveguide is provided obliquely with respect to the extending direction of the film optical waveguide.

  According to the above configuration, the core portion is provided such that the center position of the core portion is shifted from the center position of the film optical waveguide on the end surface of the film optical waveguide, and the film optical waveguide extends. It is provided obliquely with respect to the present direction.

  Conventionally, the core portion is provided so that the central axis of the core portion coincides with the central axis of the optical waveguide in the extending direction. Therefore, for example, when the film optical waveguide is bent in a direction perpendicular to the light transmission direction, the radius of curvature of the portion with the largest deformation amount in the core portion is the curvature of the portion with the largest deformation amount in the optical waveguide. Equal to the radius.

  On the other hand, in the above configuration, the core portion has a central axis in the extending direction of the core portion that is shifted from a central axis in the extending direction of the film optical waveguide, and in the extending direction of the film optical waveguide. It is the structure provided diagonally with respect to it. Thus, for example, when the film optical waveguide is bent in a direction perpendicular to its extending direction, the radius of curvature of the portion where the deformation amount is the largest in the core portion is the curvature of the portion where the deformation amount is the largest in the optical waveguide. It can be larger than the radius. Therefore, in the above configuration, it is possible to reduce bending loss due to loss variation when bent compared to the conventional configuration. Therefore, according to said structure, even when a film optical waveguide is used in the state bent, the film optical waveguide which can perform the stable optical transmission can be provided.

  Further, in order to solve the above problems, the film optical waveguide according to the present invention is composed of a plurality of core parts made of a light-transmitting material and a material having a refractive index different from the refractive index of the core part. A film optical waveguide having a clad portion configured, wherein the length of the end portion of the film optical waveguide in the width direction that is the direction in which the core portions of the end surface of the film optical waveguide are arranged is the number of the core portions In the region equally divided by the center portion, the center position in the width direction in the core portion region is shifted from the center position in the width direction in the equally divided region, the core portion is provided, and the core The part is further configured to be inclined with respect to the extending direction of the film optical waveguide.

  According to said structure, a core part is in the area | region which equally divided the length of the width direction used as the direction where the said core part in the end surface of the said film optical waveguide is arranged in the end surface of the film optical waveguide by the number of the said core parts. In the above, the center position in the width direction in the region of the core portion is provided so as to be shifted from the center position in the width direction in the equally divided region, and is provided obliquely with respect to the extending direction of the film optical waveguide. It has been.

  Thus, for example, when the film optical waveguide is bent in a direction perpendicular to its extending direction, the radius of curvature of the portion where the deformation amount is the largest in the core portion is the curvature of the portion where the deformation amount is the largest in the optical waveguide. It can be larger than the radius. Therefore, in the above configuration, it is possible to reduce bending loss due to loss variation when bent compared to the conventional configuration. Therefore, according to the above configuration, it is possible to provide a film optical waveguide capable of stable light transmission even when the arrayed film optical waveguide is used in a bent state.

  In the film optical waveguide according to the present invention, in the configuration described above, the core portion is provided obliquely and linearly with respect to the extending direction of the film optical waveguide in the film optical waveguide. Also good.

  According to said structure, the core part is provided in the film optical waveguide diagonally and linearly with respect to the extending direction of a film optical waveguide. Therefore, the curvature radius of the core portion when the film optical waveguide is bent becomes larger than the curvature radius of the film optical waveguide. Therefore, as described above, even when used in a bent state, more stable optical transmission is possible.

  In the film optical waveguide according to the present invention, in the configuration described above, the core portion is in the film optical waveguide in a region in which bending of the film optical waveguide is allowed with respect to the extending direction of the film optical waveguide. May be provided obliquely.

  According to said structure, the core part is provided diagonally with respect to the extending direction of this film optical waveguide in the area | region which accept | permits bending of this film optical waveguide in a film optical waveguide. Therefore, the curvature radius of the core portion when the film optical waveguide is bent becomes larger than the curvature radius of the film optical waveguide. Therefore, as described above, even when used in a bent state, more stable optical transmission is possible.

  Further, the film optical waveguide according to the present invention has a projection region on the light emitting side end face in the extending direction of the film optical waveguide of the core part on the light incident side end face of the film optical waveguide in the above configuration. The core portion may be provided so that a region of the core portion on the end surface on the light emitting side is symmetrical with respect to a center position on the end surface on the light emitting side.

  According to said structure, a core part is a projection area | region to the end surface of the light emission side in the extension direction of the said film optical waveguide of the core part in the light incident side end surface of the said film optical waveguide, and the said light emission side The core part region on the end face is symmetrical with respect to the center position on the end face on the light emitting side. In other words, the position of the core portion on the end surface of the film optical waveguide viewed from the light incident side is the same as the position of the core portion on the end surface of the film optical waveguide viewed from the light emitting side. Thereby, in addition to the above-mentioned effect, it becomes possible to make the structure of the mounting part which mounts the components for optical transmission / reception processing connected to a film optical waveguide common.

  Moreover, the film optical waveguide according to the present invention has the above-described configuration in the extending direction of the film optical waveguide in the end region including the entrance on the light incident side and the exit on the light exit side of the film optical waveguide. The length in the width direction perpendicular to the end region may be set to be larger than the length in the width direction in a region different from the end region.

  According to said structure, the length of the width direction perpendicular | vertical with respect to the extension direction of the said film optical waveguide in the edge part area | region which respectively includes the entrance used as the light incident side in the said film optical waveguide, and the exit used as the light output side Is set to be larger than the length in the width direction in a region different from the end region. Thereby, size reduction of a film optical waveguide can be achieved and the flexibility of a waveguide can be improved.

  In the film optical waveguide according to the present invention, in the above configuration, the light incident surface of the core portion is provided obliquely with respect to the light transmission direction, and the light irradiated from the light source is the light. You may comprise so that it may introduce | transduce into the said core part by reflecting in an entrance plane.

  According to said structure, it becomes possible to set it as the structure which arrange | positions a light source to a horizontal direction with respect to a light transmission direction with respect to a film optical waveguide. Thus, for example, when it is necessary to arrange a film optical waveguide parallel to the substrate surface, a light source is provided between the film optical waveguide and the substrate surface so that light is emitted in the normal direction of the substrate surface. Just install it. Such a configuration is easier to mount than a configuration in which, for example, the light source is installed so as to emit light parallel to the substrate surface, and the configuration can be made more compact.

  Moreover, in order to solve the above problems, a film optical waveguide module according to the present invention includes the film optical waveguide according to the present invention, a light emitting unit that emits light to the light incident surface of the film optical waveguide, A light receiving portion that receives light emitted from the light exit surface of the film optical waveguide; a holding portion that holds the film optical waveguide; and a substrate that includes the light emitting portion and the holding portion. Of the region obtained by equally dividing the length in the width direction perpendicular to the normal direction of the substrate surface at the end face of the film optical waveguide into two equal parts in the width direction, the region divided equally by the number of the core portions, It is the structure provided outside the projection area to the said board | substrate of the area | region including the center position of the said core part.

  According to the above configuration, the holding portion has an area obtained by equally dividing the length in the width direction perpendicular to the normal direction of the substrate surface at the end surface of the film optical waveguide by the number of the core portions. Further, of the region divided in half in the horizontal width direction, the region including the center position of the core portion is provided outside the region projected onto the substrate. Therefore, it is not necessary to provide a holding part in the projection area, and it can be used as a space for mounting each component. Specifically, for example, a light emitting unit or a light receiving unit and an electric wiring connected to the light emitting unit or the light receiving unit can be mounted. Thereby, compared with the conventional structure, since the area | region required in order to provide a holding | maintenance part on a board | substrate can be saved, size reduction of a film optical waveguide module is realizable.

  Moreover, since the said film optical waveguide is used, even if it uses it in the state which bent the film optical waveguide, the bending loss resulting from the loss fluctuation | variation when bent can be reduced. Furthermore, in the above configuration, since the end portion of the film optical waveguide can be reliably held, performance deterioration due to coupling loss due to deformation of the end portion of the film optical waveguide is unlikely to occur. Therefore, according to said structure, even when used in the bent state, the film optical waveguide module which can perform the stable optical transmission can be provided.

  The holding portion may be formed integrally with the substrate or the film optical waveguide.

  In the film optical waveguide module according to the present invention, in the configuration described above, the light emitting unit irradiates light from a direction substantially perpendicular to the light transmission direction in the film optical waveguide with respect to the film optical waveguide. In addition, the film optical waveguide may be configured to introduce the light irradiated from the light emitting part into the core part by reflecting the light on the light incident surface.

  According to said structure, it becomes possible to set it as the structure which arrange | positions a light emission part in a substantially perpendicular direction with respect to a light transmission direction with respect to a film optical waveguide. Therefore, for example, when it is necessary to dispose a film optical waveguide parallel to the substrate surface, the light emitting unit emits light in the normal direction of the substrate surface between the film optical waveguide and the substrate surface. It would be good to install. Such a configuration is easier to mount than a configuration in which, for example, the light emitting unit is installed so as to emit light in parallel to the substrate surface, and the configuration can be made more compact.

  As described above, in the film optical waveguide according to the present invention, the core portion has a center position of the core portion in the cross section perpendicular to the extending direction of the film optical waveguide. It is the structure provided by deviating from.

  In the film optical waveguide according to the present invention, as described above, the core portion is provided such that the center position of the core portion is shifted from the center position of the film optical waveguide at the end surface of the film optical waveguide. And is provided obliquely with respect to the extending direction of the film optical waveguide.

  Further, as described above, the film optical waveguide according to the present invention has the length in the width direction, which is the direction in which the core portions are aligned in the end surface of the film optical waveguide, at the end surface of the film optical waveguide. In the region equally divided by the center portion, the center position in the width direction in the core portion region is shifted from the center position in the width direction in the equally divided region, the core portion is provided, and the core The part is further configured to be inclined with respect to the extending direction of the film optical waveguide.

  Thereby, the bending loss caused by the loss fluctuation when bent can be reduced. Therefore, even when the film optical waveguide is used in a bent state, the film optical waveguide capable of stable light transmission can be provided.

  In the film optical waveguide module according to the present invention, the length of the holding portion in the width direction perpendicular to the normal direction of the substrate surface at the end surface of the film optical waveguide is the number of the core portions. Of the regions obtained by further dividing the equally divided region into two in the horizontal width direction, the region including the center position of the core portion is provided outside the region projected onto the substrate.

  Thereby, since an area necessary for providing the holding portion on the substrate can be saved, it is possible to provide a film optical waveguide module capable of stable optical transmission and capable of being downsized. Play.

  An embodiment of the present invention is described below with reference to the drawings.

(Configuration of optical waveguide module)
FIG. 2 shows a schematic configuration of the optical waveguide module 1 according to the present embodiment. As shown in the figure, an optical waveguide module (film optical waveguide module) 1 includes an optical transmission processing unit 2, an optical reception processing unit 3, and an optical waveguide (film optical waveguide) 4.

  The optical transmission processing unit 2 includes a light emission drive unit 5 and a light emission unit 6. The light emission driving unit 5 drives the light emission of the light emitting unit 6 based on an electric signal input from the outside. The light emission drive unit 5 is constituted by, for example, an IC (Integrated Circuit) for light emission drive. Although not shown, the light emission drive unit 5 is provided with an electrical connection portion with an electrical wiring for transmitting an electrical signal from the outside.

  The light emitting unit 6 emits light based on drive control by the light emission driving unit 5. The light emitting unit 6 is configured by a light emitting element such as a VCSEL (Vertical Cavity-Surface Emitting Laser). The light emitted from the light emitting unit 6 is applied to the light incident side end of the optical waveguide 4 as an optical signal.

  The optical reception processing unit 3 includes an amplification unit 7 and a light receiving unit 8. The light receiving unit 8 receives light as an optical signal emitted from the light emitting side end of the optical waveguide 4 and outputs an electric signal by photoelectric conversion. The light receiving unit 8 is configured by a light receiving element such as a PD (Photo-Diode).

  The amplifying unit 7 amplifies the electrical signal output from the light receiving unit 8 and outputs it to the outside. The amplifying unit 7 is configured by an amplification IC, for example. Although not shown, the amplifying unit 7 is provided with an electrical connection with electrical wiring for transmitting an electrical signal to the outside.

  The optical waveguide 4 is a medium that transmits light emitted from the light emitting unit 6 to the light receiving unit 8. Details of the configuration of the optical waveguide 4 will be described later.

  FIG. 3 schematically shows the state of light transmission in the optical waveguide 4. As shown in the figure, the optical waveguide 4 is constituted by a columnar member having flexibility. Further, a light incident reflection surface (light incident surface) 4A is provided at the light incident side end of the optical waveguide 4, and a light output reflection surface (light emitting surface) 4B is provided at the light output side end. ing.

  The light emitted from the light emitting unit 6 enters the light incident side end of the optical waveguide 4 from a direction substantially perpendicular to the light transmission direction of the optical waveguide 4. The incident light travels in the optical waveguide 4 by being reflected by the light incident reflection surface 4A. The light that travels through the optical waveguide 4 and reaches the light exit side end is reflected by the light exit reflection surface 4B and is emitted in a direction substantially perpendicular to the light transmission direction of the optical waveguide 4. . The emitted light is irradiated to the light receiving unit 8, and photoelectric conversion is performed in the light receiving unit 8.

  According to such a configuration, it is possible to adopt a configuration in which the light emitting unit 6 as a light source is disposed in a direction transverse to the optical transmission direction with respect to the optical waveguide 4. Therefore, for example, when it is necessary to arrange the optical waveguide 4 parallel to the substrate surface, the light emitting unit is configured to emit light in the normal direction of the substrate surface between the optical waveguide 4 and the substrate surface. 6 should be installed. Such a configuration is easier to mount than a configuration in which, for example, the light emitting unit 6 is installed so as to emit light parallel to the substrate surface, and the configuration can be made more compact. This is because the general configuration of the light emitting unit 6 is larger in size in the direction perpendicular to the direction of emitting light than in the direction of emitting light. Furthermore, the present invention can also be applied to a configuration in which a light emitting element for planar mounting having an electrode and a light emitting portion 6 in the same plane is used.

(Configuration of optical waveguide)
FIG. 1 shows a front view and a side view of the optical waveguide 4. As shown in the figure, the optical waveguide 4 includes a columnar core portion 11 having an optical transmission direction as an axis, and a cladding portion 12 provided so as to surround the core portion 11. Yes. The core part 11 and the clad part 12 are made of a light-transmitting material, and the refractive index of the core part 11 is higher than the refractive index of the clad part 12. The optical signal incident on the core unit 11 is transmitted in the optical transmission direction by repeating total reflection inside the core unit 11.

  As a material constituting the core portion 11 and the clad portion 12, glass, plastic, or the like can be used. However, in order to constitute the optical waveguide 4 having sufficient flexibility, acrylic, epoxy, It is preferable to use resin materials such as urethane and silicone. Moreover, you may comprise the clad part 12 with gas, such as air. Further, the same effect can be obtained even when the cladding portion 12 is used in a liquid atmosphere having a refractive index smaller than that of the core portion 11. The cross-sectional shape of the core part 11 in a plane perpendicular to the light transmission direction is a rectangle.

  Here, at the end face of the optical waveguide 4, the direction in which the optical waveguide 4 is held is the Y direction, the extending direction of the optical waveguide 4 is the Z direction, and the direction perpendicular to the YZ plane, that is, the lateral width direction at the end face of the optical waveguide 4. X direction.

  As shown in FIG. 1, the core portion 11 is provided such that the X-direction center axis C <b> 1 on the end surface of the core portion 11 is shifted from the X-direction center axis C <b> 2 on the end surface of the optical waveguide 4. That is, when the end surface of the optical waveguide 4 is viewed from above (Z direction) in FIG. 1, the core portion 11 has a length of a region on the upper side (X direction) of the core portion 11 and a lower side (X The length of the region of (direction) is different. Therefore, even when an optical waveguide having the same external dimensions as the conventional one is used, at one end of the optical waveguide 4, a region other than the core portion 11, that is, one region in the X direction (core portion 11) in the region around the core portion 11. Large area) can be secured. One region other than the core portion 11 serves as a holding region for holding the end portion of the optical waveguide 4.

  Here, an example of the method for cutting the optical waveguide 4 will be briefly described. FIG. 4 is a top view showing an example of a method for cutting the optical waveguide 4. As the cutting method, for example, in an arrayed optical waveguide, an optical waveguide 4 in which the position of the core portion is shifted is manufactured by cutting the inside of the core portion 11 instead of the region between the core portions 11. It becomes possible to do. Thereby, the holding region can be secured at the end of the optical waveguide 4. Further, a method of adhering the portion to be the holding region to the side surface of the optical waveguide 4 may be used.

(Configuration of optical waveguide and light emitting / receiving section)
Next, the configuration for holding the end portion of the optical waveguide 4 will be described together with the configurations of the optical waveguide 4 and the light emitting unit 6 and the optical waveguide 4 and the light receiving unit 8. In addition, since the structure of the optical waveguide 4 and the light-emitting part 6 and the structure of the optical waveguide 4 and the light-receiving part 8 are respectively the same structures, here, for convenience of explanation, the structures of the optical waveguide 4 and the light-emitting part 6 are described. To do.

  FIG. 5 is a perspective view showing a schematic configuration of the optical waveguide module 1. FIG. 6 is a top view of the optical waveguide module 1 shown in FIG. As shown in FIGS. 5 and 6, the optical waveguide module 1 further includes a substrate 10 having a holding portion 9. In the present embodiment, the holding portion 9 is formed integrally with the substrate 10 and functions as a region for holding the optical waveguide 4 in the substrate 10.

  The holding unit 9 is a holding region for placing the optical waveguide 4 on the upper surface thereof and maintaining a constant distance between the optical waveguide 4 and the light emitting unit 6 (or the light receiving unit 8). The height of the holding unit 9 is set in advance so that the optical coupling efficiency between the optical waveguide 4 and the light emitting unit 6 (or the light receiving unit 8) becomes a desired value.

  The substrate 10 is for mounting the optical transmission processing unit 2 and the optical waveguide 4 described above. Although not shown, the optical reception processing unit 3 side has the same configuration.

  The electrical wiring 13 mounted on the substrate 10 connects the light emission drive unit 5 and the light emission unit 6 and transmits an electrical signal. Specifically, a flexible printed circuit board (FPC), a coaxial cable, a lead frame, etc. are mentioned, for example.

  Here, an example of an optical coupling method of the optical waveguide 4 and the light emitting unit 6 together with the manufacturing method of the optical waveguide module 1 will be described below with reference to FIGS. 5, as described above, in the end face of the optical waveguide 4, the direction in which the optical waveguide 4 is held is the Y direction, the extending direction of the optical waveguide 4 is the Z direction, and the direction perpendicular to the YZ plane, that is, The horizontal width direction at the end face of the optical waveguide 4 is defined as the X direction.

  First, the light emission drive unit 5, the electrical wiring 13, and the light emission unit 6 are mounted in advance on the upper surface of the substrate 10 fixed by a jig or the like by a method such as soldering. Next, an adhesive is applied to the surface of the holding unit 9 on which the optical waveguide 4 is mounted. Various commercially available adhesives can be used. Next, the optical waveguide 4 is handled using an air chuck or the like, and the optical waveguide 4, the light emitting unit 6, the holding unit 9 and the image recognition device (not shown) installed above the substrate 10 (Y direction). Adjust the position of. In the image of the image recognition device, the light incident area at the light incident side end of the optical waveguide 4 and the light emitting area of the light emitting section 6 coincide with each other and are held by the holding section 9 at the end of the optical waveguide 4. The optical waveguide 4 is placed on the holding part 9 and bonded at a position where the holding area and the upper surface area of the holding part 9 coincide. In this way, the optical waveguide 4 can be optically coupled in a state where one side of the end portion of the optical waveguide 4 is held and the distance between the optical waveguide 4 and the light emitting portion 6 is kept constant.

  In the present embodiment, the holding unit 9 and the optical waveguide 4 are combined with an adhesive, but the present invention is not limited to this. For example, an adhesive sheet, heat fusion, UV fusion, or the like is used. The structure which couple | bonds may be sufficient.

  Moreover, in this Embodiment, although the holding part 9 and the board | substrate 10 are formed integrally, both may be comprised as a separate member. Furthermore, in order to set the distance between the optical waveguide 4 and the light emitting unit 6 to a desired value and reduce the mounting process of the holding unit 9 on the substrate 10, the holding unit 9 and the optical waveguide 4 are integrated. It is good also as the structure currently formed.

(Coupling loss, bending loss)
Here, the coupling loss and the bending loss that occur in the optical transmission by the optical waveguide 4 will be described. These coupling loss and bending loss hinder stable optical transmission, and it is necessary to reduce both losses.

  The coupling loss is a loss of light that occurs when light from the light source (corresponding to the light emitting unit 6) enters the optical waveguide 4. This will be described in detail as follows. A certain amount of space is provided between the light source and the optical waveguide 4. This is provided to absorb an error in the installation position of the light source and the optical waveguide 4 and an error in the component size. That is, the light emitted from the light source enters the optical waveguide 4 via the above-described interval. Here, the light emitted from the light source cannot be completely incident on the optical waveguide 4, and the loss of light generated here becomes the coupling loss. Further, in the optical waveguide having flexibility, the end portion thereof is easily deformed due to the influence of vibration or heat. When such an end of the optical waveguide is deformed, the distance between the light source and the optical waveguide 4 fluctuates, and light emitted from the light source cannot be reliably incident on the optical waveguide 4, resulting in coupling loss. . Therefore, in order to reduce this coupling loss, it is necessary to keep the distance between the light source and the optical waveguide 4 constant.

  The bending loss is a loss of light caused by bending the optical waveguide 4. This will be described in detail as follows. The light transmitted through the optical waveguide 4 is transmitted in the optical transmission direction by repeating total reflection inside the core portion 11. Here, in order for the light to be totally reflected, the incident angle with respect to the inner surface of the core portion 11 needs to be equal to or larger than a predetermined angle. On the other hand, when the optical waveguide 4 is bent, the probability that the incident angle of the light impinging on the inner surface of the core portion 11 opposite to the bent direction becomes small is increased. As a result, the transmitted light is not totally reflected on the inner surface of the core portion 11, and a part thereof is transmitted to the outside. The loss of light generated here becomes the bending loss. Therefore, in order to reduce this bending loss, it is effective to increase the radius of curvature of the core portion 11 when the optical waveguide 4 is bent.

  In the optical waveguide 4 according to the present embodiment, as shown in FIG. 1, the core portion 11 has a central axis C <b> 1 in the horizontal width direction (X direction) of the core portion 11 in the horizontal width direction (X direction) of the optical waveguide 4. For example, as shown in FIG. 7, when the optical waveguide 4 is bent in a direction twisted with respect to its extending direction, the core portion 11 is most allowed to bend because it is provided so as to be shifted from the central axis C2. That is, it avoids the portion where the deformation occurs, that is, the portion with the largest deformation amount.

  On the other hand, the core portion 11 is provided such that the central axis C1 in the horizontal width direction (X direction) of the core portion 11 coincides with the central axis C2 in the horizontal width direction (X direction) of the optical waveguide 4. For example, when the optical waveguide 4 is bent in a direction twisted with respect to the extending direction, the core portion 11 passes through a portion that allows the most bending, that is, a portion having the largest deformation amount.

  Thereby, according to the optical waveguide 4 which concerns on this Embodiment, since it becomes possible to take the curvature radius of the core part 11 when the optical waveguide 4 is bent compared with the conventional structure, bending Bending loss due to loss fluctuation at the time can be reduced. Therefore, according to the optical waveguide 4, stable optical transmission is possible even when used in a bent state.

  Further, when the optical waveguide 4 is used in the optical waveguide module 1, the end of the optical waveguide 4 can be reliably held as shown in FIGS. Thus, the distance between the light emitting unit 6 and the optical waveguide 4 can be kept constant. Therefore, since the coupling loss due to the variation in the distance between the light emitting portion 6 and the optical waveguide 4 due to the deformation of the end portion of the optical waveguide 4 can be suppressed, stable optical transmission is possible. Further, since only one side of the end portion of the optical waveguide 4 is held, the region on the other side can be effectively utilized as a space for the electrical wiring 13 connected to the light emitting unit 6 and the light receiving unit 8. As a result, the entire optical waveguide module 1 can be reduced in size.

(Modification 1)
In the configuration of the optical waveguide 4 of the present embodiment, a modified example of the configuration shown in FIG. 1 will be described. FIG. 8 shows a front view and a side view of the optical waveguide 4 as the first modification. FIG. 9 shows a curved state of the optical waveguide 4 as the first modification.

  In the configuration shown in FIG. 1, the core portion 11 has a configuration in which the central axis C <b> 3 in the Y direction in the core portion 11 coincides with the central axis C <b> 4 in the Y direction in the optical waveguide 4 at the end face of the optical waveguide 4. In the configuration of Modification Example 1, as shown in FIG. 8, the core portion 11 has a central axis C3 that does not coincide with the central axis C4, and a region where bending in the optical waveguide 4 occurs (a region that allows bending). The optical waveguide 4 is configured to pass through a region inside the curve due to bending of the optical waveguide 4 and to pass through a region outside the curve due to bending in a region where bending does not occur (outside the region allowing bending). There may be.

  Thereby, the curvature radius of the core part 11 when the optical waveguide 4 is bent becomes larger than the curvature radius of the optical waveguide 4. Therefore, since the bending loss can be further reduced as compared with the configuration of FIG. 1, the optical transmission efficiency can be increased, and more stable optical transmission is possible.

(Modification 2)
In the configuration of the optical waveguide 4 of the present embodiment, another modification of the configuration shown in FIG. 1 will be described. FIG. 10 shows a front view and a side view of the optical waveguide 4 as the second modification. FIG. 11 shows a curved state of the optical waveguide 4 shown in FIG.

  As shown in FIG. 10, the core portion 11 has an extending direction (Z direction) of the optical waveguide 4 in a region from the light incident side end portion to the light emitting side end portion of the optical waveguide 4 in the XZ plane. May be provided obliquely and linearly. In addition, as shown in FIG. 12, the core portion 11 is provided obliquely with respect to the extending direction (Z direction) of the optical waveguide 4 in a region where the bending of the optical waveguide 4 is allowed in the XZ plane. May be.

  11 and 12, the radius of curvature of the core portion 11 when the optical waveguide 4 is bent is larger than the radius of curvature of the optical waveguide 4 as shown in FIG. 11. Therefore, since the bending loss can be reduced as compared with the conventional configuration, the optical transmission efficiency can be increased, and more stable optical transmission is possible.

(Modification 3)
In the configuration of the optical waveguide 4 of the present embodiment, another modification of the configuration shown in FIG. 1 will be described. FIG. 13 shows a front view and a side view of the optical waveguide 4 as the third modification.

  In the configuration shown in FIG. 1, the projection region of the core portion 11 on the light incident side end surface onto the light emitting side end surface in the extending direction of the optical waveguide 4 (Z direction) is the core on the light emitting side end surface. The core portion 11 is provided so as to coincide with the region of the portion 11. However, in the configuration of the third modification, as illustrated in FIG. 13, the core portion 11 on the end surface on the light incident side is provided. The projected area on the light exit side end face in the extending direction (Z direction) of the optical waveguide 4 and the area of the core portion 11 on the end face on the light exit side are in the lateral width direction (X direction) on the end face of the optical waveguide 4. ) May be provided so as to be symmetrical to each other.

  According to this configuration, the distance between the central axis C1 of the core portion 11 and the central axis C2 of the optical waveguide 4 at the end surface on the light incident side, and the central axis C1 ′ of the core portion 11 and the optical waveguide at the end surface on the light emission side. The distance between the four central axes C2 'is the same. That is, the position of the core portion 11 on the end face of the optical waveguide 4 viewed from the light incident side is the same as the position of the core portion 11 on the end face of the optical waveguide 4 viewed from the light exit side. Thereby, it is possible to share the configuration of the mounting parts of the components in the optical transmission processing unit 2 and the optical reception processing unit 3. Note that the configuration of Modification 5 can also be applied to the configurations shown in FIGS. 10 and 12 in Modification 2.

(Modification 4)
In the configuration of the optical waveguide 4 of the present embodiment, another modification of the configuration shown in FIG. 1 will be described. FIG. 14 shows a front view and a side view of the optical waveguide 4 as the fourth modification. In the configuration shown in FIG. 1, the length w1 in the horizontal width direction of the optical waveguide 4 is not changed toward the extending direction of the optical waveguide 4, but in the configuration of the modification 4, as shown in FIG. 4 may be set so that the length w1 in the horizontal width direction in the holding area holding 4 is larger than the length w2 in the horizontal width outside the holding area. That is, in the optical waveguide 4, the length in the width direction (X direction) is large only in the region held by the holding unit 9. Thereby, size reduction of the optical waveguide 4 can be achieved and flexibility can be improved.

(Modification 5)
In the configuration of the optical waveguide 4 of the present embodiment, another modification of the configuration shown in FIG. 1 will be described. FIG. 15 shows a front view and a side view of the optical waveguide 4 as the fifth modification. As shown in the figure, in the optical waveguide 4 having a plurality of core parts 11, the length w in the lateral width direction (X direction) perpendicular to the direction of holding the optical waveguide 4 at the end face of the optical waveguide 4 is defined as the core part 11. In the regions w3 and w4 equally divided by the number, the center axes C5 and C6 in the width direction of the core portion 11 and the center axes C7 and C8 in the width direction of the region do not match each other.

  Thereby, it becomes possible to hold | maintain the area | region of one side among the area | region between each core part 11, and the area | region of the optical waveguide 4 in a X direction. For this reason, the holding portion 9 is not required in the other region, so that the optical waveguide module 1 as a whole can be reduced in size. In the example shown in the figure, the optical waveguide 4 is configured to include two core portions 11, but the number of core portions 11 may be two or more.

(Modification 6)
In the configuration of the optical waveguide module 1 of the present embodiment, another modification of the configuration shown in FIG. 6 will be described. FIG. 16 shows a top view of the optical waveguide module 1 as the sixth modification. As shown in the figure, the optical waveguide 4 is mounted obliquely with respect to the longitudinal direction (Z direction) of the substrate 10 in the XZ plane. Thereby, when the optical waveguide 4 is in a curved state, it is possible to prevent the light emitting side substrate 10 and the light receiving side substrate 10 from coming into contact with each other in the bending direction, and in comparison with the conventional configuration. Since bending loss can be reduced, more stable optical transmission is possible.

(Example)
In the configuration of the optical waveguide module 1 of the present embodiment, a specific example of the configuration shown in FIG. 1 will be described. FIG. 17 shows a top view of the substrate 10 and the holding portion 9 as this embodiment. In the present embodiment, the holding unit 9 and the substrate 10 are configured as separate members.

  As shown in the figure, the length L1 in the X direction of the holding portion 9 serving as the holding region of the optical waveguide 4 is 150 μm or more, and the substrate 9 is mounted on the substrate in order to mount the light emitting portion 6 or the light receiving portion 8. The distance L2 to the inner wall surface of 10 is preferably 400 μm or more in the X direction. Although not shown, in order to ensure the strength of the optical waveguide 4, the length in the thickness direction (Y direction) of the optical waveguide 4 is preferably 50 μm or more and the elastic modulus is preferably 1 GPa or more. . The sizes of the core portion 11 and the cladding portion 12 of the optical waveguide 4 are determined in consideration of the arrangement space of the optical elements such as the light emitting portion 6 or the light receiving portion 8 and the thickness and width of the optical waveguide 4. The

(Application examples)
The optical waveguide 4 of the present embodiment can be applied to the following application examples, for example.

  First, as a first application example, it is used for a hinge part in a foldable electronic device such as a foldable mobile phone, a foldable PHS (Personal Handyphone System), a foldable PDA (Personal Digital Assistant), and a foldable notebook personal computer. it can.

  FIGS. 18A to 18C show an example in which the optical waveguide 4 is applied to a foldable mobile phone 40. That is, FIG. 18A is a perspective view showing the appearance of a foldable mobile phone 40 incorporating the optical waveguide 4.

  FIG. 18B is a block diagram of a portion to which the optical waveguide 4 is applied in the foldable mobile phone 40 shown in FIG. As shown in this figure, the control unit 41 provided on the main body 40a side in the foldable mobile phone 40, and the lid (drive unit) 40b provided on one end of the main body so as to be rotatable about a hinge part. An external memory 42, a camera unit (digital camera) 43, and a display unit (liquid crystal display display) 44 are connected by an optical waveguide 4.

  FIG. 18C is a perspective plan view of the hinge portion (portion surrounded by a broken line) in FIG. As shown in this figure, the optical waveguide 4 is wound around a holding rod in the hinge portion and bent, thereby controlling the control portion provided on the main body side, the external memory 42 provided on the lid side, the camera portion 43, A display unit 44 is connected to each other.

  By applying the optical waveguide 4 to these foldable electronic devices, high-speed and large-capacity communication can be realized in a limited space. Therefore, it is particularly suitable for devices that require high-speed and large-capacity data communication, such as a foldable liquid crystal display device, and are required to be downsized.

  As a second application example, the optical waveguide 4 can be applied to an apparatus having a drive unit such as a printer head in a printing apparatus (electronic device) or a reading unit in a hard disk recording / reproducing apparatus.

  FIGS. 19A to 19C show an example in which the optical waveguide 4 is applied to the printing apparatus 50. FIG. 19A is a perspective view showing the appearance of the printing apparatus 50. As shown in this figure, the printing apparatus 50 includes a printer head 51 that performs printing on the paper 52 while moving in the width direction of the paper 52, and one end of the optical waveguide 4 is connected to the printer head 51. ing.

  FIG. 19B is a block diagram of a portion where the optical waveguide 4 is applied in the printing apparatus 50. As shown in this figure, one end of the optical waveguide 4 is connected to the printer head 51, and the other end is connected to the main body side substrate in the printing apparatus 50. The main body side substrate is provided with control means for controlling the operation of each unit of the printing apparatus 50.

  FIGS. 19C and 19D are perspective views showing the curved state of the optical waveguide 4 when the printer head 51 is moved (driven) in the printing apparatus 50. As shown in this figure, when the optical waveguide 4 is applied to a driving unit such as the printer head 51, the bending state of the optical waveguide 4 is changed by driving the printer head 51, and each position of the optical waveguide 4 is repeatedly bent. Is done.

  Therefore, the optical waveguide 4 according to the present embodiment is suitable for these drive units. Further, by applying the optical waveguide 4 to these drive units, high-speed and large-capacity communication using the drive units can be realized.

  FIG. 20 shows an example in which the optical waveguide 4 is applied to a hard disk recording / reproducing device 60.

  As shown in this figure, the hard disk recording / reproducing apparatus 60 includes a disk (hard disk) 61, a head (reading / writing head) 62, a substrate introducing part 63, a driving part (driving motor) 64, and the optical waveguide 4. .

  The drive unit 64 drives the head 62 along the radial direction of the disk 61. The head 62 reads information recorded on the disk 61 and writes information on the disk 61. The head 62 is connected to the substrate introduction part 63 via the optical waveguide 4, and propagates information read from the disk 61 to the substrate introduction part 63 as an optical signal and is propagated from the substrate introduction part 63. The optical signal of information to be written on the disk 61 is received.

  Thus, by applying the optical waveguide 4 to a drive unit such as the head 62 in the hard disk recording / reproducing apparatus 60, high-speed and large-capacity communication can be realized.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  The optical waveguide module and the optical waveguide according to the present invention can be applied to an optical communication path between various devices, and can also be applied to a flexible optical wiring as an in-device wiring mounted in a small and thin consumer device. Is possible.

It is the front view and side view of the optical waveguide which concern on one Embodiment of this invention. It is a figure which shows schematic structure of the optical waveguide module which concerns on this embodiment. It is a figure which shows typically the state of the optical transmission in an optical waveguide. It is a figure explaining an example of the manufacturing method of an optical waveguide. It is a perspective view which shows schematic structure of the optical waveguide module which concerns on this embodiment. It is a top view which shows schematic structure of the optical waveguide module shown in FIG. It is a perspective view which shows the curved state of the optical waveguide shown in FIG. It is the front view and side view of an optical waveguide as a modification. It is the front view and side view which show the curved state of the optical waveguide as a modification shown in FIG. It is the front view and side view of the optical waveguide as another modification. (A) And (b) is a perspective view which shows the curved state of the optical waveguide shown in FIG. It is the front view and side view of the optical waveguide as another modification. It is the front view and side view of the optical waveguide as another modification. It is the front view and side view of the optical waveguide as another modification. It is the front view and side view of the optical waveguide as another modification. It is a top view which shows schematic structure of an optical waveguide module as another modification. It is a top view of the board | substrate and holding | maintenance part as an Example. (A) is a perspective view which shows the external appearance of the foldable mobile phone provided with the optical waveguide according to the present embodiment, and (b) is an application of the optical waveguide in the foldable mobile phone shown in (a). FIG. 4C is a perspective plan view of a hinge portion in the foldable mobile phone shown in FIG. (A) is a perspective view which shows the external appearance of the printing apparatus provided with the optical waveguide which concerns on this embodiment, (b) is a block diagram which shows the principal part of the printing apparatus shown to (a), (c) and (d) are perspective views showing the curved state of the optical waveguide when the printer head is moved (driven) in the printing apparatus. It is a perspective view which shows the external appearance of the hard-disk recording / reproducing apparatus provided with the optical waveguide which concerns on this embodiment.

Explanation of symbols

1 Optical waveguide module (film optical waveguide module)
2 Optical transmission processing unit 3 Optical reception processing unit 4 Optical waveguide (film optical waveguide)
DESCRIPTION OF SYMBOLS 5 Light emission drive part 6 Light emission part 7 Amplification part 8 Light reception part 9 Holding part 10 Substrate 11 Core part 12 Clad part 13 Electric wiring

Claims (14)

A film optical waveguide comprising a core portion made of a light-transmitting material and a clad portion made of a material having a refractive index different from the refractive index of the core portion,
The core part is the person the film waveguide in the extending direction perpendicular to the direction of the cross section, the center position of the core portion is provided in a manner in which regardless whether the center position of the film light guide,
The center position of the core portion on both end faces of the light incident side and the light exit side of the film light guide is shifted to the same side with respect to the center position of the film light guide in the direction of holding the film light guide,
When the film optical waveguide is bent on the side opposite to the central position of the core portion in the direction of holding the film optical waveguide with reference to the center position of the film optical waveguide on the both end faces,
The film optical waveguide characterized in that the core portion is provided so that the center position of the core portion is shifted from the center position of the film optical waveguide to the outside of the curve due to bending of the film optical waveguide on the both end faces . A film optical waveguide comprising a core portion made of a light-transmitting material and a clad portion made of a material having a refractive index different from the refractive index of the core portion,
The core portion, the end face of the person the film waveguide, the center position of the core portion is provided in a manner in which regardless whether the center position of the film waveguide, with respect to the extending direction of the film waveguide It is provided diagonally ,
The center position of the core portion on both end faces of the light incident side and the light exit side of the film light guide is shifted to the same side with respect to the center position of the film light guide in the direction of holding the film light guide,
When the film optical waveguide is bent on the side opposite to the central position of the core portion in the direction of holding the film optical waveguide with reference to the center position of the film optical waveguide on the both end faces,
The film optical waveguide characterized in that the core portion is provided so that the center position of the core portion is shifted from the center position of the film optical waveguide to the outside of the curve due to bending of the film optical waveguide on the both end faces . A film optical waveguide comprising a plurality of core parts made of a light-transmitting material and a clad part made of a material having a refractive index different from the refractive index of the core part,
In the end face of the person the film waveguide in the length of the width direction which is a direction in which the core portion at the end face of the film waveguide are aligned and equally by the number of the core portions in the region, said in the region of the core portion center position of the width direction, the equally divided been Raz or the center position of the width direction of the region, with the core section is provided,
The core part is further provided obliquely with respect to the extending direction of the film optical waveguide ,
The center position of the core portion on both end faces of the light incident side and the light exit side of the film light guide is shifted to the same side with respect to the center position of the film light guide in the direction of holding the film light guide,
When the film optical waveguide is bent on the side opposite to the central position of the core portion in the direction of holding the film optical waveguide with reference to the center position of the film optical waveguide on the both end faces,
The film optical waveguide characterized in that the core portion is provided so that the center position of the core portion is shifted from the center position of the film optical waveguide to the outside of the curve due to bending of the film optical waveguide on the both end faces .   The said core part is diagonally and linearly provided with respect to the extending direction of the said film optical waveguide in the said film optical waveguide, The any one of Claims 1-3 characterized by the above-mentioned. The film optical waveguide as described.   The core part is provided obliquely with respect to the extending direction of the film optical waveguide in a region where the bending of the film optical waveguide is allowed in the film optical waveguide. 5. The film optical waveguide according to any one of 4 above.   Projection area of the core part on the light incident side end face of the film optical waveguide onto the light emitting side end face in the extending direction of the film optical waveguide, and the core part area on the light emitting side end face, The film optical waveguide according to any one of claims 2 to 5, wherein the core portion is provided so as to be symmetrical with respect to a center position on an end face on the light emission side.   The length in the width direction perpendicular to the extending direction of the film optical waveguide in the end region including the entrance on the light incident side and the exit on the light exit side of the film optical waveguide is the end region. The film optical waveguide according to claim 1, wherein the film optical waveguide is set to be larger than the length in the width direction in a region different from the region. A film optical waveguide comprising a core portion made of a light-transmitting material and a clad portion made of a material having a refractive index different from the refractive index of the core portion,
In the cross section in the direction perpendicular to the extending direction of the film optical waveguide, the core portion is provided with the center position of the core portion shifted from the center position of the film optical waveguide,
The length in the width direction perpendicular to the extending direction of the film optical waveguide in the end region including the entrance on the light incident side and the exit on the light exit side of the film optical waveguide is the end region. A film optical waveguide, which is set to be larger than the length in the width direction in a region different from the above. A film optical waveguide comprising a core portion made of a light-transmitting material and a clad portion made of a material having a refractive index different from the refractive index of the core portion,
In the end surface of the film optical waveguide, the core portion is provided so that the center position of the core portion is shifted from the center position of the film optical waveguide, and is inclined with respect to the extending direction of the film optical waveguide. Provided,
The length in the width direction perpendicular to the extending direction of the film optical waveguide in the end region including the entrance on the light incident side and the exit on the light exit side of the film optical waveguide is the end region. A film optical waveguide, which is set to be larger than the length in the width direction in a region different from the above. A film optical waveguide comprising a plurality of core parts made of a light-transmitting material and a clad part made of a material having a refractive index different from the refractive index of the core part,
In the end face of the film optical waveguide, the horizontal width in the area of the core portion in the area obtained by equally dividing the length in the horizontal width direction, which is the direction in which the core portions are arranged in the end face of the film optical waveguide, by the number of the core portions The center position in the direction is shifted from the center position in the width direction in the equally divided region, the core portion is provided,
The core part is further provided obliquely with respect to the extending direction of the film optical waveguide,
The length in the width direction perpendicular to the extending direction of the film optical waveguide in the end region including the entrance on the light incident side and the exit on the light exit side of the film optical waveguide is the end region. A film optical waveguide, which is set to be larger than the length in the width direction in a region different from the above.   The light incident surface of the core part is provided obliquely with respect to the light transmission direction, and the light irradiated from the light source is introduced into the core part by being reflected by the light incident surface. It is comprised, The film optical waveguide of any one of Claims 1-10 characterized by the above-mentioned. The film optical waveguide according to any one of claims 1 to 11,
A light emitting unit for irradiating light to the light incident surface of the film optical waveguide;
A light receiving portion for receiving light emitted from the light exit surface of the film optical waveguide;
A holding portion for holding the film optical waveguide;
A substrate having the light emitting unit and the holding unit,
The holding portion further includes two in the width direction for each region obtained by equally dividing the length in the width direction perpendicular to the normal direction of the substrate surface at the end face of the film optical waveguide by the number of the core portions. A film optical waveguide module, wherein an area including the center position of the core portion is provided outside the area projected onto the substrate among the equally divided areas. The light emitting unit irradiates the film optical waveguide with light from a direction substantially perpendicular to the light transmission direction in the film optical waveguide,
The film optical waveguide module according to claim 12, wherein the film optical waveguide introduces light irradiated from the light emitting portion into the core portion by reflecting the light on a light incident surface.   An electronic device comprising the film optical waveguide module according to claim 12 or 13.

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