JP2011096207A - Optical pointing device and electronic device with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pointing device that reduces effect due to stray light on image data imaged in an image sensor, and to provide an electronic device with the same. <P>SOLUTION: The optical pointing device includes a light source 16 for irradiating an object with light, a light guide type optical member 24 for reflecting and guiding reflected light from the object, and the image sensor 15 for receiving the light guided by the light guide type optical member 24. The light source 16 is housed in a structure 20 composed of a translucent resin. The structure 20 is provided with a notched part 25 having an erected surface 20a erected toward an object direction at a part on the side of the image sensor 15 and near the object, in order to prevent the light emitted from the light source 16 from being guided by the light guide type optical member 24 and received by the image sensor 15 without being reflected at the object. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical pointing device and an electronic device including the same, and more specifically, an optical pointing device as an input device that can be mounted on a portable information terminal (electronic device) such as a mobile phone or a PDA (Personal Digital Assistants). The present invention relates to an apparatus and an electronic apparatus including the apparatus.

  In a small electronic device typified by a portable information terminal such as a mobile phone or a PDA, a keypad is generally employed as a user interface for inputting information. The keypad is usually composed of a plurality of buttons for inputting numbers and characters and direction buttons (cross keys). In recent years, with the display of graphics and the like being possible on the display unit of a portable information terminal, a GUI (Graphical User Interface) that mainly uses the display unit in two dimensions has been adopted as a method for displaying information to the user. It is becoming.

  As described above, since the portable information terminal is highly functional and has a display function equivalent to that of a computer, the input means of the conventional portable information terminal that uses menu keys and other function keys as direction keys are expressed in GUI. It is not suitable for selecting an icon or the like and is inconvenient. For this reason, a portable information terminal is required to have a pointing device that enables intuitive operation, such as a mouse such as a ball mouse or an optical mouse used in a computer, a touch pad, or a tablet. ing.

  However, since the portable information terminal is assumed to be carried, there is a problem in adopting a separate pointing device separated from the main body as the pointing device of the portable information terminal. In addition, a track ball-type pointing device occupies a three-dimensional space that is physically larger than a certain level, and thus has a problem that it is difficult to adopt it for a thin and small portable information terminal.

  Therefore, as a pointing device that can be mounted on a portable information terminal, a subject (for example, a fingertip) that contacts the pointing device is observed with an image sensor, and a change in the pattern of the subject (for example, a fingerprint) on the contact surface is extracted. Has proposed an optical pointing device that detects the movement of a subject. That is, an image of a subject formed by light reflected by the subject is continuously captured by an image sensor such as an image sensor, and a change amount of the captured image data with respect to the image data captured immediately before is extracted. There has been proposed an optical pointing device that calculates the movement of a subject based on the amount and outputs it as an electrical signal. By using this optical pointing device, the cursor or the like shown on the display can be moved in accordance with the movement of the subject.

  For example, Patent Document 1 discloses a reflecting mirror that reflects light emitted from a light source and reflected by a subject in a horizontal direction (when the apparatus is placed horizontally), and vertically facing a horizontal ray path. An optical pointing device including an installed condensing lens and an image sensor (imaging device) is described (see abstract of Patent Document 1).

  In the optical pointing device of Patent Document 1, light emitted from a light source is shielded by a block-shaped light shielding wall provided with a reflecting mirror so as not to directly enter the image sensor. That is, in the optical pointing device of Patent Document 1 that guides light to the image sensor with a reflecting mirror, the light emitted from the light source becomes stray light (light that does not pass through a prescribed light path) without being reflected by the subject. Therefore, it is possible to easily prevent light from being received.

Special table 2008-507787 (published March 13, 2008)

  By the way, in recent years, a light guide type optical member that reflects and guides reflected light from a subject has been used as an optical member in place of an optical pointing device configured to combine a plurality of mirrors such as a reflecting mirror to guide light to an imaging device. Various optical pointing devices have been proposed.

  However, in the optical pointing device using the light guide type optical member, since the light is guided through the inside of the light guide type optical member, the block-shaped light shielding wall or the like cannot be provided, so that stray light is shielded. It has the problem that it cannot be done. When stray light is received by the image sensor, the light (scattered light) reflected by the subject cannot be sufficiently recognized by the effect of stray light when the image sensor receives light reflected from the subject. The performance of the pointing device is reduced. Therefore, a countermeasure for preventing stray light from being received by the image sensor is demanded.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to reduce the influence of stray light on image data captured by an image sensor in an optical pointing device using a light guide type optical member. Another object of the present invention is to provide an optical pointing device and an electronic apparatus including the same.

  In order to solve the above problems, an optical pointing device according to the present invention includes a light source that irradiates light to a subject, a light guide type optical member that reflects and guides reflected light from the subject, and the light guide. An optical pointing device including an imaging element that receives light guided by a mold optical member, wherein the light source is accommodated in a structure made of a light-transmitting resin, and the structure is imaged In order to prevent light emitted from the light source from being guided by the light guide type optical member and reflected by the imaging element on the element side and near the subject without being reflected by the subject. It is characterized in that a notch portion having a standing surface standing upright is provided.

  According to said structure, the notch part which has the standing surface standing up toward a to-be-photographed object side is provided in the site | part close | similar to a to-be-photographed object side in the structure which accommodates a light source. For this reason, the light emitted from the light source and reaching the standing surface is refracted and travels toward the subject when passing through the standing surface. That is, it is possible to prevent the light emitted from the light source from becoming stray light without being reflected by the subject. That is, in the optical pointing device using the light guide type optical member, it is possible to provide an optical pointing device in which the influence of stray light on the image data captured by the imaging element is reduced. Further, since the light emitted from the light source and reaching the standing surface can be advanced toward the subject, it is possible to improve the utilization efficiency of the light emitted from the light source.

  In the optical pointing device according to the present invention, the light guide type optical member is configured to reflect the reflected light from the subject in order to guide the reflected light in the light guide direction, and further to guide the light reflected by the reflection unit. It is more preferable to provide an imaging reflection unit that reflects and forms an image in the opposite direction to the direction, and guides the light reflected by the imaging reflection unit to the imaging element to form an image.

  In the optical pointing device according to the present invention, it is more preferable that the light emitting surface of the light source is a flat surface, and the standing surface is erected perpendicularly to the light emitting surface.

  Alternatively, in the optical pointing device according to the present invention, the light emitting surface of the light source is a flat surface, and the standing surface is erected so as to incline to the imaging element side or the opposite side with respect to the light emitting surface. More preferably.

  Further, in the optical pointing device according to the present invention, it is more preferable that the standing surface is provided so as to be positioned on the image sensor side end portion of the light emitting surface of the light source when viewed from the subject side. .

  Alternatively, in the optical pointing device according to the present invention, the standing surface is provided so as to be positioned closer to the image sensor than the end on the image sensor side of the light emitting surface of the light source when viewed from the subject side. It is more preferable.

  In the optical pointing device according to the present invention, the light emitted from the light source is guided by the light guide type optical member to the image sensor side end portion of the notch and reflected by the subject and received by the image sensor. In order to prevent this, it is more preferable that a light shielding member is provided.

  According to each of the above configurations, optical pointing in which the influence of stray light on the image data captured by the image sensor is further reduced according to various conditions such as the relative positional relationship between the light source, the subject, and the image sensor. An apparatus can be provided.

  In order to solve the above-described problems, an electronic apparatus according to the present invention includes the above-described optical pointing device.

  According to said structure, the electronic device provided with the optical pointing device by which the influence by the stray light with respect to the image data imaged with the image pick-up element was reduced can be provided.

  As described above, in the optical pointing device according to the present invention, the light emitted from the light source is guided to the structure body by the light guide type optical member on the image sensor side and near the subject without being reflected by the subject. In order to prevent light from being received by the image sensor, a notch portion having a standing surface standing toward the subject direction is provided.

  Thereby, in the optical pointing device using the light guide type optical member, there is an effect that it is possible to provide an optical pointing device in which the influence of stray light on the image data captured by the image sensor is reduced. Moreover, there is an effect that the utilization efficiency of the light emitted from the light source can be improved.

  In addition, an electronic apparatus according to the present invention includes the optical pointing device described above. Thereby, there is an effect that it is possible to provide an electronic apparatus including an optical pointing device in which the influence of stray light on the image data captured by the image sensor is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view illustrating a schematic configuration of an optical pointing device according to a first embodiment of the present invention. It is sectional drawing which shows the structure of the principal part of the said optical pointing device. It is a modification of the said optical pointing device, Comprising: It is sectional drawing which shows the structure of the principal part. It is a further modification of the said optical pointing device, Comprising: It is sectional drawing which shows the structure of the principal part. FIG. 5 is a cross-sectional view illustrating a configuration of a main part of an optical pointing device according to a second embodiment of the present invention. It is a reference example for explaining an embodiment of the present invention, and is a sectional view showing a schematic structure in an optical pointing device. In the optical pointing device according to the first embodiment of the present invention, it is a graph for explaining the effect produced by providing a notch in the structure.

(Reference example of optical pointing device)
FIG. 6 is a cross-sectional view showing a schematic configuration of an optical pointing device as a reference example for explaining the embodiment of the present invention. As shown in FIG. 6, in the optical pointing device 100 using the light guide type optical member 140 in which the optical elements are integrated, since a light shielding wall or the like cannot be provided, the light is emitted from the light emitting surface 101 a of the light source 101. A part of the light is refracted when passing through the structure 101 made of a translucent resin, and is received by the image sensor 104 as stray light 103 without being reflected by the subject. When the stray light 103 is received by the image sensor 104, the light (scattered light) is sufficiently recognized by the influence of the stray light 103 when the image sensor 104 receives the light (scattered light) reflected by the subject. The performance of the optical pointing device 100 is deteriorated. Therefore, a countermeasure for preventing the stray light 103 from being received by the image sensor 104 is required.

(Embodiment of the present invention)
Next, an embodiment of the present invention will be described by taking an optical pointing device using an LED (light emitting diode) as a light source as an example. The optical pointing device according to the present invention is mounted as an input device in, for example, a portable information terminal (electronic device) such as a mobile phone or a PDA. The optical pointing device detects movement of a subject by irradiating a subject (for example, a fingertip) with light from a light source and receiving light reflected from the subject with an image sensor. . Hereinafter, the configuration of the optical pointing device of each embodiment will be specifically described. In the following description, members having the same function and action are denoted by the same reference numerals, and the subsequent description is omitted.

[First embodiment]
1st Embodiment of this invention is described based on FIGS.

(Schematic configuration of optical pointing device)
FIG. 1 is a cross-sectional view showing a schematic configuration of an optical pointing device. As shown in FIG. 1, the optical pointing device 30 includes a circuit board 21, a light source 16 composed of LEDs, a structure 20, an imaging element 15, a light-transmitting resin member 22, and a light guide type optical member 24. The cover part which has is provided.

  The light source 16 irradiates a subject (for example, a fingertip or the like) 10 with light (an example of a prescribed ray path is indicated by “arrow” in FIG. 1). The light source 16 disposed on the circuit board 21 is accommodated in a structure 20 made of a translucent resin, and forms a light source module. Specifically, the light source 16 is resin-sealed (molded) with a translucent resin. As the translucent resin, for example, a thermosetting resin such as silicone resin or epoxy resin, or a thermoplastic resin such as ABS (Acrylonitrile Butadiene Styrene) resin is used. The approximate shape of the structure 20 is preferably, for example, a cubic shape or a semi-cylindrical shape extending along the longitudinal direction of the imaging element 15, but is not particularly limited. The detailed shape of the structure 20 will be described later. The bottom surface of the structure 20 is in close contact with the surface of the circuit board 21 (the surface facing the contact surface 11). Note that the structure 20 may include a hemispherical lens portion that condenses the light emitted from the light source 16 on the surface (the surface facing the contact surface 11) as necessary.

  The light guide type optical member 24 is formed with a contact surface 11 that is in contact with the subject 10 so as to face the light source 16. The light guide type optical member 24 that reflects and guides the reflected light from the subject 10 is made of a material having a higher refractive index than air. The subject 10 in contact with the contact surface 11 is an object whose movement is detected by the optical pointing device 30. The light guide type optical member 24 constituting the cover portion includes an inclined portion (reflecting portion) 13 and a reflecting member 17 that reflect the reflected light from the subject 10 in the light guiding direction, and the reflecting portion 13 and the reflecting member. Further, an image forming element (image forming reflection unit) 14 is formed which reflects the light reflected by 17 in the opposite direction to the light guide direction and forms an image. The light reflected by the imaging element 14 is further reflected by the reflecting member 17 and guided to the imaging element 15 to form an image. In FIG. 1, the size of the optical pointing device 30 with respect to the subject 10 is exaggerated for convenience of explanation.

  The board portion has a light source 16 and an image sensor 15 mounted on a single circuit board 21. The planar circuit board 21 is made of the same material, and is composed of, for example, a printed board or a lead frame. On the circuit board 21, a circuit for controlling the light emission timing of the light source 16 and detecting the movement of the subject 10 in response to an electric signal output from the image sensor 15 is formed. The light source 16 and the imaging device 15 are electrically connected to the circuit of the circuit board 21 by wire bonding or flip chip mounting.

  The light source 16 is disposed at a position where light can be emitted toward the contact surface 11. The light emitted from the light emitting surface 16 a of the light source 16 passes through the structure 20 and the inclined portion 13 and is refracted to change its traveling direction, and reaches the contact surface 11. That is, light is incident on the contact surface 11 from an oblique direction (with a certain range of incident angles with respect to the contact surface 11). Since the light guide type optical member 24 is made of a material having a refractive index larger than that of air, a part of the light reaching the contact surface 11 comes into contact when the subject 10 is not on the contact surface 11. The surface 11 is transmitted, and the remaining part is reflected by the contact surface 11. At this time, when the incident angle of the light with respect to the contact surface 11 satisfies the condition of total reflection, the light does not pass through the contact surface 11 but is totally reflected by the contact surface 11 toward the light guide type optical member 24. . On the other hand, when the subject 10 is on the contact surface 11, the light reaching the contact surface 11 is reflected (diffusely reflected) on the surface of the subject 10 in contact with the contact surface 11, and a part of the light is of a light guide type. It goes to the inside of the optical member 24. As the light source 16, it is preferable to use, for example, an LED or the like having a flat light emitting surface 16a, and it is particularly preferable to use a high-luminance infrared light emitting diode.

  The imaging element 15 is arranged so that the surface thereof is parallel to the contact surface 11, and is resin-sealed (molded) with a translucent resin member 22 to form an imaging element module. As a material of the translucent resin member 22, for example, a thermosetting resin such as silicone resin or epoxy resin, or a thermoplastic resin such as ABS (Acrylonitrile Butadiene Styrene) is used. The shape of the translucent resin member 22 is preferably, for example, a cubic shape extending along the longitudinal direction of the imaging element 15, but is not particularly limited. The bottom surface of the translucent resin member 22 is in close contact with the surface of the circuit board 21 (the surface facing the contact surface 11).

  The image pickup device 15 that receives light guided by the light guide type optical member 24 includes an image sensor such as a complementary metal-oxide semiconductor (CMOS) or a charge coupled device (CCD), and a DSP (Digital Signal Processor) (not shown). : A calculation unit), and the received light is taken into the DSP as image data. That is, the image sensor 15 receives light emitted from the light source 16 and reflected by the subject 10, forms an image on the contact surface 11 based on the received light, and converts the image into image data. Yes. The image sensor 15 continues to capture images on the contact surface 11 (for example, a pattern such as a fingerprint) at regular intervals in accordance with a signal instruction from the circuit board 21.

  Therefore, when the subject 10 in contact with the contact surface 11 moves, the image captured by the image sensor 15 is different from the image captured immediately before that. The imaging element 15 compares the values at the same location of the captured image data with the image data captured immediately before by the DSP, and calculates the movement amount and movement direction of the subject 10. That is, when the subject 10 moves on the contact surface 11, the photographed image data shows a value that deviates by a predetermined amount from the image data photographed immediately before. For this reason, the image sensor 15 extracts a change amount of the imaged image data with respect to the image data captured immediately before by the DSP, and calculates a movement amount and a movement direction of the subject 10 based on the change amount. The image sensor 15 outputs the calculated movement amount and movement direction to the circuit board 21 as electric signals.

  More specifically, the image sensor 15 captures an image of the contact surface 11 when the subject 10 is not on the contact surface 11. Next, when the subject 10 comes into contact with the contact surface 11, the imaging element 15 captures an image of the surface of the subject 10 that is in contact with the contact surface 11. For example, when the subject 10 is a fingertip, the image sensor 15 captures a fingerprint as an image. Here, since the image data captured by the image sensor 15 is different from the image data when the subject 10 is not present on the contact surface 11, the DSP of the image sensor 15 captures the subject 10 on the contact surface 11. A signal indicating that is touching is transmitted to the circuit board 21. Then, when the subject 10 moves on the contact surface 11, the movement amount and movement direction of the subject 10 are calculated compared to the image data captured immediately before by the DSP, and a signal indicating the calculated movement amount and movement direction is used as a circuit. Transmit to the substrate 21.

  The DSP may be included in the circuit board 21 instead of in the image sensor 15. In that case, the image sensor 15 may be configured to sequentially transmit the captured image data to the circuit board 21.

  The substrate portion is integrally configured by the circuit board 21, the light source 16, the structure 20, the image sensor 15, and the translucent resin member 22. Therefore, the number of parts of the optical pointing device 30 can be reduced, and the number of assembly processes can also be reduced. Therefore, the manufacturing cost of the optical pointing device 30 can be reduced, and the detection accuracy of the movement of the subject can be improved.

  The cover part includes the light guide type optical member 24 and the like, and protects each part and each element on the substrate part side such as the light source 16 and the image sensor 15. The cover part is located on the upper side (subject 10 side) of the substrate part, and is in close contact with the side surface and the surface (the surface facing the contact surface 11) of the substrate part. The shape of the optical pointing device 30 mainly formed by the cover portion and the substrate portion is preferably a cubic shape, but is not particularly limited. The contact surface 11 is a surface where the subject 10 is in contact with the optical pointing device 30. The contact surface 11 is the surface of the cover part (that is, the surface of the light guide type optical member 24) and is located above the light source 16.

  The inclined portion (reflecting portion) 13 is one surface of the prism constituting the light guide type optical member 24, is located above the light source 16 and below the contact surface 11, and does not contact the substrate portion on the back surface of the cover portion. It is formed in the place. The inclined portion 13 transmits and refracts the light emitted from the light source 16 to convert the light path so as to go to the contact surface 11 (that is, the subject 10), while the reflected light from the subject 10 is reflected on the imaging element 15. The light is totally reflected so as to be guided in the direction toward the light (light guide direction). In other words, the inclined portion 13 is totally reflected so as to guide light incident on the light guide type optical member 24 from the contact surface 11 after being reflected by the subject 10 in the horizontal direction (when the apparatus is placed horizontally). It is supposed to be. Therefore, the prism including the inclined portion 13 is made of a material having a refractive index larger than that of air. Specifically, a visible light absorption type polycarbonate resin or acrylic resin having a refractive index of about 1.5 is used for the prism.

  The light guided by the inclined portion 13 is guided through the light guide type optical member 24, reflected by the reflecting member 17, and irradiated on the imaging element 14. The reflection member 17 causes the light totally reflected by the inclined portion 13 to enter the imaging element 14, reflects the light reflected from the imaging element 14, and enters the imaging element 15. The reflection member 17 is located above the image sensor 15 and on the surface of the cover portion (that is, the surface of the light guide type optical member 24). The reflecting member 17 is provided by depositing aluminum or the like on the surface of the cover portion to form a reflecting film. Since the reflective film is exposed to the outside and can be seen by the user, it is desirable that the reflective film be as inconspicuous as possible. For example, when the wavelength of light emitted from the light source 16 is an infrared wavelength outside the visible wavelength (for example, 800 nm or more), the reflection film forming the reflection member 17 may be an infrared reflection film. That is, the reflecting film forming the reflecting member 17 may be any film that reflects infrared light having a wavelength band of 800 nm or more emitted from the light source 16 and transmits light having a visible wavelength band of 800 nm or less. Thereby, it is possible to form the reflecting member 17 that efficiently reflects the reflected light from the subject 10 and is inconspicuous in appearance.

  Further, when the wavelength of light emitted from the light source 16 is an infrared wavelength outside the visible wavelength (for example, 800 nm or more), the cover portion (that is, the light guide type optical member 24) transmits only infrared light. The visible light absorption type polycarbonate resin or acrylic resin may be used. By forming the cover portion with such a material, visible light components can be blocked by the cover portion from unnecessary light entering from the outside of the cover portion. As described above, by forming the reflection member 17 that reflects infrared light, the infrared light component of the unnecessary light can be blocked by the reflection member 17. Accordingly, by blocking unnecessary light incident on the optical pointing device 30, malfunction due to the unnecessary light can be prevented.

  The imaging element 14 includes toroidal surfaces having different curvatures in two directions orthogonal to each other, and is disposed on the opposite side of the contact surface 11 and the light source 16 with the imaging element 15 interposed therebetween. A reflective film is formed on the toroidal surface serving as a reflective lens by depositing metal (for example, aluminum, nickel, gold, silver, dielectric dichroic film, etc.). The imaging element 14 reflects the reflected light from the subject 10 on the toroidal surface in a direction opposite to the light guide direction of the reflected light (a direction toward the imaging element 15), and the object 10 is reflected on the imaging element 15. An image is formed. That is, the imaging element 14 reflects the light reflected by the inclined portion 13 in the horizontal direction (when the apparatus is placed horizontally) in the reverse direction and guides the light to the imaging element 15 to form an image. It has become. The light reflected by the imaging element 14 is emitted from the emission part of the light guide type optical member 24 and enters the imaging element 15 to form an image.

  The reflection member 18 is positioned between the imaging element 15 and the imaging element 14 on the back surface of the cover portion (that is, the back surface of the light guide type optical member 24) so as to face the reflection member 17. The reflecting member 18 and the reflecting member 17 reflect the reflected light from the imaging element 14 and make it incident on the imaging element 15. The reflective member 18 is provided by depositing a metal (for example, aluminum, nickel, gold, silver, dielectric dichroic film, etc.) on the back surface of the cover portion to form a reflective film.

  The cover part is integrally constituted by the light guide type optical member 24 including the imaging element 14, the reflection member 17, the reflection member 18, and the like. Therefore, the number of parts of the optical pointing device 30 can be reduced, and the number of assembly processes can also be reduced. Therefore, the manufacturing cost of the optical pointing device 30 can be reduced, and the detection accuracy of the movement of the subject can be improved.

  Therefore, when the subject 10 is in contact with the contact surface 11, the prescribed light path until the light emitted from the light source 16 is reflected by the subject 10 and enters the image sensor 15 is as follows. That is, the light emitted from the light source 16 first passes through the structure 20 and the inclined portion 13 and is refracted to reach the contact surface 11. The light that has reached the contact surface 11 is reflected (diffusely reflected) on the surface of the subject 10 that is in contact with the contact surface 11, passes through the light guide optical member 24, is totally reflected by the inclined portion 13, and is horizontally ( When the apparatus is placed horizontally), the light is guided. The light totally reflected by the inclined portion 13 (reflected light) is reflected by the reflecting member 17 and reaches the imaging element 14. Then, the light reflected by the imaging element 14 is further reflected by the reflecting member 18 and the reflecting member 17 and enters the imaging element 15. Thereby, the imaging device 15 can detect the movement of the subject 10.

(Detailed shape of the structure)
The detailed shape of the structure 20 in the optical pointing device 30 configured as described above will be described below. FIG. 2 is a cross-sectional view illustrating a configuration of a main part of the optical pointing device 30. As shown in FIG. 2, in the structure 20, the light emitted from the light emitting surface 16 a of the light source 16 is not reflected by the subject 10 at the site on the image sensor 15 side and close to the contact surface 11. In order to prevent light from being guided by the member 24 and received by the image sensor 15, that is, light from becoming stray light and received by the image sensor 15. A cutout portion 25 having a surface 20a and a lateral surface 20b intersecting (orthogonal) with the standing surface 20a is provided. Specifically, the standing surface 20a is perpendicular to the light emitting surface 16a, which is a plane, and the normal direction thereof is in the horizontal direction toward the image sensor 15 (the device is placed horizontally). (When installed) is formed (standing). Furthermore, is the standing surface 20a provided so as to be positioned on the end of the light emitting surface 16a of the light source 16 on the image sensor 15 side when viewed from the contact surface 11 side (that is, the subject 10 side)? Alternatively, it is preferable that the light emitting surface 16 a of the light source 16 is provided so as to be positioned closer to the image sensor 15 side than the end of the image sensor 15 side. The lateral surface 20b is formed to be horizontal with respect to the light emitting surface 16a.

  By providing the notch 25 in the structure 20, the light emitted from the light source 16 and reaching the standing surface 20a, that is, the light incident at an acute incident angle with respect to the standing surface 20a is When passing through the installation surface 20a, the light is refracted toward the contact surface 11 (that is, the subject 10) and proceeds toward the contact surface 11 (that is, the subject 10) (an example of stray light in FIG. 2). Is indicated by an “arrow”). That is, the standing surface 20a changes the incident angle of the light with respect to the light guide type optical member 24 by changing the light beam angle of the light emitted from the light emitting surface 16a of the light source 16, thereby changing the contact surface 11 (that is, The ray path is converted so as to go to the subject 10). Therefore, the light emitted from the light emitting surface 16a of the light source 16 is guided by the light guide type optical member 24 without being reflected by the subject 10 and is received by the imaging element 15, that is, the light becomes stray light. It is possible to prevent the image sensor 15 from receiving light.

  By providing the cutout portion 25 in the structure 20, as an example, stray light can be reduced by 25% compared to a case where the cutout portion 25 is not provided (for example, the configuration described in FIG. 6). Here, in the optical pointing device 30, the effect produced by providing the notch 25 in the structure 20 will be described more specifically. FIG. 7 is a graph for explaining the effect obtained by providing the structure 20 with the notch 25 in the optical pointing device 30, and FIG. 7A shows a case where the structure is not provided with a notch. It is a graph which shows illuminance distribution, (b) is a graph which shows the illuminance distribution at the time of providing the notch part 25 in the structure 20 (this invention), (c) is the graph which synthesize | combined the said both graphs. . The horizontal axis of the graph represents that the illuminance distribution of the image sensor was measured with the light source side end of the image sensor positioned at the left end and the imaging element side end of the image sensor positioned at the right end. The vertical axis of the graph represents the ratio of the illuminance with respect to the maximum illuminance of stray light when the cutout is not provided in the structure as “1”. Therefore, the maximum value in the graph of (a) is “1”. From the graph of FIG. 7A, it can be seen that when the structure is not provided with a notch, a large amount of stray light is irradiated particularly near the light source side end of the image sensor. On the other hand, from the graph of FIG. 7B, it can be seen that when the cutout portion 25 is provided in the structure 20, stray light is hardly irradiated over the entire image sensor 15. That is, as is clear from the graph of FIG. 7C, by providing the notch 25 in the structure 20, it is possible to prevent the light emitted from the light source 16 from becoming stray light without being reflected by the subject 10. You can see that you can.

  The dimension of the notch 25, that is, the height of the standing surface 20a from the lateral surface 20b is the inclination angle of the inclined portion 13, the distance from the light source 16 to the contact surface 11, the light source 16 and the contact surface 11 (that is, When various conditions such as the relative positional relationship between the subject 10) and the image sensor 15 are the same, a higher one is preferable because stray light can be further reduced. In particular, the standing surface 20a is positioned closer to the image sensor 15 than the image sensor 15 side end of the light emitting surface 16a of the light source 16 when viewed from the contact surface 11 side (that is, the subject 10 side). If the above conditions are the same, it is preferable that the height of the standing surface 20a is higher because the effect of reducing stray light becomes more significant. The distance from the light emitting surface 16a to the horizontal surface 20b, that is, the thickness of the portion of the structure 20 where the horizontal surface 20b is formed is preferably thicker. Thereby, it can further prevent that the light radiate | emitted from the light source 16 becomes stray light.

  However, the dimensions of the notch 25 are the inclination angle of the inclined portion 13, the distance from the light source 16 to the contact surface 11, and the relative positional relationship between the light source 16, the contact surface 11 (that is, the subject 10) and the image sensor 15. It is necessary to make a decision by conducting a simulation in consideration of various conditions such as the above. Therefore, as a result of the simulation, for example, as shown in FIG. 3 which is a modified example of the optical pointing device 30 and is a cross-sectional view showing the configuration of the main part, the standing surface 20a from the lateral surface 20b. In some cases, the light emitted from the light source 16 can be prevented from becoming stray light (an example of stray light is indicated by “arrow” in FIG. 3). Therefore, the height of the standing surface 20a from the lateral surface 20b may be a height that can prevent the light emitted from the light source 16 from becoming stray light.

  With the above configuration, it is possible to provide the optical pointing device 30 in which the influence of stray light on the image data captured by the image sensor 15 is reduced. Further, since the light emitted from the light source 16 and reaching the standing surface 20a can be advanced toward the contact surface 11 direction (that is, the direction of the subject 10), the light (effective light) irradiated to the subject 10 with stray light can be increased. Can be used as part. That is, the utilization efficiency of the light emitted from the light source 16 can be improved. Further, by providing the notch 25 in the structure 20, the inclined portion 13 can be brought closer to the light source 16 as compared with the case where it is not provided (for example, the configuration described in FIG. 6). Therefore, the optical pointing device 30 can be further reduced in size (thinned).

  An electronic apparatus according to the present invention includes the optical pointing device 30 having the above-described configuration. Therefore, it is possible to provide an electronic apparatus including the optical pointing device 30 in which the influence of stray light on the image data captured by the image sensor 15 is reduced.

(Modification of the shape of the structure)
The standing surface 20a is preferably erected perpendicularly to the light emitting surface 16a, but the contact surface 11 side end may be inclined to the image sensor 15 side or the opposite side. However, the inclination angle of the standing surface 20 a is the inclination angle of the inclined portion 13, the distance from the light source 16 to the contact surface 11, and the relative position of the light source 16, the contact surface 11 (that is, the subject 10) and the image sensor 15. It is necessary to make a decision by conducting a simulation in consideration of various conditions such as relationships.

  FIG. 4 is a cross-sectional view showing a configuration of a main part as a further modification of the optical pointing device 30. As shown in FIG. 4, the optical pointing device 30 in the modified example has a hemispherical lens unit that condenses the light emitted from the light source 16 on the surface of the structure 20 (the surface facing the contact surface 11). 20d is formed, and the standing surface 20c is formed obliquely with respect to the light emitting surface 16a so that the end portion on the contact surface 11 side is inclined to the opposite side of the imaging element 15, and intersects the standing surface 20c. And a notch 25 ′ having a lateral surface 20b. That is, the contact surface 11 side end of the standing surface 20 c of the notch 25 ′ is inclined to the opposite side of the image sensor 15. By making the structure 20 have the above-described configuration, more light emitted from the light source 16 can be applied to the contact surface 11, the SN ratio can be improved, and the luminance (illuminance) distribution on the contact surface 11 can be improved. (An example of stray light is indicated by “arrow” in FIG. 4).

  The standing surfaces 20a and 20c are on the inner side of the light emitting surface 16a of the light source 16 on the image sensor 15 side when viewed from the contact surface 11 side (that is, the subject 10 side), that is, the above-described surface. The light source 16 can also be provided so as to be positioned closer to the image sensor 15 side end on the light emitting surface 16a (position closer to the image sensor 15 side end than the center of the light emitting surface 16a). In this case, the influence of stray light can be reduced and the luminance distribution on the contact surface 11 can be made more uniform.

[Second Embodiment]
A second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the description of the same configuration as that described in the first embodiment is omitted.

  FIG. 5 is a cross-sectional view illustrating a configuration of a main part of the optical pointing device. As shown in FIG. 5, the optical pointing device according to the present embodiment has a light guide type optical member that does not reflect the light emitted from the light source 16 on the subject 10 at the end of the notch 25 on the image sensor 15 side. In order to prevent light from being guided by 24 and being received by the image sensor 15, a light shielding member 28 is provided. That is, in the optical pointing device according to the present embodiment, the light shielding body 28 is provided so as to be in close contact with the structure 20 and the circuit board 21. The height of the light shield 28 (the length from the end on the circuit board 21 side to the end on the contact surface 11 side) is the height of the structure 20 (the length from the end on the circuit board 21 side to the end on the contact surface 11 side). Is the same as or lower than The thickness of the light shield 28 (the length from the light source 16 side end to the image sensor 15 side end) is not particularly limited.

  By providing the light shield 28, the light emitted from the light source 16 and reaching the horizontal surface 20b is blocked by the light shield 28 after passing through the horizontal surface 20b. Therefore, the light emitted from the light emitting surface 16a of the light source 16 is guided by the light guide type optical member 24 without being reflected by the subject 10 and is received by the imaging element 15, that is, the light becomes stray light. It is possible to prevent the image sensor 15 from receiving light (an example of stray light is indicated by “arrow” in FIG. 5).

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

  INDUSTRIAL APPLICABILITY The present invention is suitable for an optical pointing device as an input device that can be mounted on a portable information terminal (electronic device) that is particularly required to be small and thin, such as a mobile phone and a PDA, and an electronic device including the same. Can be used.

10 Subject 11 Contact surface 13 Inclined part (reflective part)
14 Imaging element (imaging reflector)
DESCRIPTION OF SYMBOLS 15 Image pick-up element 16 Light source 16a Light emission surface 17 Reflective member 18 Reflective member 20 Structure 20a Standing surface 20b Lateral surface 20c Standing surface 21 Circuit board 24 Light guide type optical member 25 Notch part 25 'Notch part 28 Light shielding member 30 Optical pointing device

Claims (8)

A light source that irradiates light to a subject, a light guide type optical member that reflects and guides reflected light from the subject, and an image sensor that receives light guided by the light guide type optical member An optical pointing device,
The light source is housed in a structure made of a translucent resin,
The structure prevents the light emitted from the light source from being guided by the light guide type optical member and received by the image sensor without being reflected by the subject at a position close to the subject on the image sensor side. In order to achieve this, an optical pointing device having a notch portion having a standing surface that stands up toward the subject.   The light guide type optical member reflects the reflected light from the subject to guide the light in the light guide direction, and further reflects the light reflected by the reflector in a direction opposite to the light guide direction. The optical pointing device according to claim 1, further comprising: an imaging reflection unit that forms an image together with the light, and the light reflected by the imaging reflection unit is guided to the imaging element to form an image.   3. The optical pointing device according to claim 1, wherein the light emitting surface of the light source is a flat surface, and the standing surface is erected perpendicularly to the light emitting surface.   The light emitting surface of the light source is a flat surface, and the standing surface is erected so as to incline to the imaging element side or the opposite side with respect to the light emitting surface. The optical pointing device described.   The said standing surface is provided so that it may be located on the image sensor side edge part in the light emission surface of the said light source when it sees from a to-be-photographed object side. An optical pointing device according to claim 1.   The said standing surface is provided so that it may be located in the image pick-up element side rather than the image pick-up element side edge part in the light emission surface of the said light source when it sees from a to-be-photographed object side. The optical pointing device according to any one of the above.   In order to prevent the light emitted from the light source from being guided by the light guide type optical member without being reflected by the subject and received by the image sensor at the image sensor side end of the notch. The optical pointing device according to any one of claims 1 to 6, wherein a member is provided.   An electronic apparatus comprising the optical pointing device according to claim 1.

Images