JP4746118B2 - Optical pointing device and electronic device including the same - Google Patents

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). It relates to the device.

  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.

  On the other hand, in recent years, with the miniaturization of devices found in mobile phones and the high integration found in devices having a plurality of functions, there has been a demand for smaller and thinner input devices. Therefore, an optical pointing device that has been reduced in size and thickness has been proposed (Patent Documents 2 and 3).

Special table 2008-507787 (published March 13, 2008) JP 2008-226224 A (published September 25, 2008) Special table 2008-510248 gazette (released April 3, 2008)

  However, since the optical pointing device described in Patent Documents 2 and 3 is reduced in size and thickness, the optical system or the like is reduced or the capacity is reduced. Since no light shielding wall or the like can be provided, stray light cannot be shielded. 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 of the present invention is to provide an optical pointing device in which the influence of stray light on image data captured by an image sensor is reduced even in a thin optical pointing device, And providing an electronic apparatus including the same.

  In order to solve the above problems, an optical pointing device of the present invention includes a light source that irradiates light to a subject, a light guide type optical member that reflects reflected light from the subject and guides the inside, and the light guide. An optical pointing device including an imaging element that receives light guided by the optical optical member, wherein the optical guiding member includes an imaging reflection unit that guides the guided light to the imaging element. And stray light that changes the path of light that is emitted from the light source and is incident on the image sensor without passing through the imaging reflector on the back surface of the light guide optical member on which the light source and the image sensor are provided. It is characterized by having a prevention part.

  According to the above configuration, the light guide type optical member is provided with a countermeasure (stray light countermeasure) against light that is directly incident on the imaging element without the light emitted from the light source being reflected by the subject. That is, a stray light prevention unit that prevents light emitted from the light source from entering the imaging element without being reflected by the subject is formed on the back surface of the light guide type optical member. Accordingly, when light that has not been reflected by the subject that causes stray light among the light emitted from the light source reaches the stray light prevention unit, the path changes when the light is emitted from the stray light prevention unit. Therefore, the light emitted from the light source can be prevented from becoming stray light without being reflected by the subject.

  Moreover, according to said structure, since the stray light prevention part is formed in the back surface of a light guide type optical member, stray light can be prevented also in a thin optical pointing device.

  Therefore, even in a thin optical pointing device, it is possible to provide an optical pointing device that can reduce the influence of stray light on the image data captured by the image sensor.

  The stray light prevention unit is preferably provided so as to avoid a path of signal light for detecting the subject. Thereby, it is possible to prevent stray light from entering the imaging element without reducing the detection sensitivity of the signal light.

  In the optical pointing device according to the aspect of the invention, the light guide type optical member may change the direction of the reflected light from the subject by changing the direction of the reflected light from the subject, the contact surface with which the subject is in contact, and the imaging reflective portion. It is preferable that the optical path conversion part to guide is integrally formed.

  According to the above configuration, the light guide type optical member has a contact surface with which the subject comes into contact, an imaging reflection unit that guides the guided light to the imaging reflection unit, and reflection from the subject reflected by the contact surface. An optical path conversion unit that converts the optical path of light and guides it to the imaging reflection unit, and these are integrally formed. That is, an optical system that is an essential component in the optical pointing device is integrally formed. As a result, even if the optical path length of the optical system is increased and aberrations are suppressed, the length of the light guide type optical member in the vertical direction can be made smaller than the optical path length. Therefore, further downsizing and thinning of the optical pointing device can be realized. Further, by integrally molding, the light guide type optical member can be assembled with high accuracy, and the number of parts can be reduced.

  In the optical pointing device of the present invention, the stray light prevention unit may be a prism that refracts the guided light.

  According to the above configuration, since the stray light prevention unit is formed of a prism, the light source light that is not reflected by the subject that causes stray light is reflected in a specific direction by the stray light prevention unit. Therefore, it is possible to reliably prevent the light emitted from the light source from becoming stray light without being reflected by the subject.

  In the optical pointing device of the present invention, the stray light prevention unit may include a refractive surface that scatters the guided light.

  According to said structure, since the stray light prevention part consists of a refractive surface, the light source light which was not reflected by the to-be-photographed object which causes stray light is refracted by the stray light prevention part. Therefore, it is possible to reliably prevent the light emitted from the light source from becoming stray light without being reflected by the subject.

  In the optical pointing device of the present invention, the stray light prevention unit may be formed of a light shielding member that shields light that has been shielded.

  According to said structure, since the stray light prevention part consists of a light shielding member, the light source light which was not reflected by the to-be-photographed object causing stray light is shielded by the stray light prevention part. Therefore, it is possible to reliably prevent the light emitted from the light source from becoming stray light without being reflected by the subject.

  The light shielding member is preferably made of a black film. Since the black film has a property of absorbing light, the stray light prevention unit absorbs light source light that has not been reflected by the subject that causes stray light. Therefore, it is possible to reliably reduce the influence of stray light and provide an optical pointing device with high subject detection accuracy.

  In the optical pointing device of the present invention, it is preferable that the stray light prevention unit is integrally formed with the contact surface, the imaging reflection unit, and the optical path conversion unit.

  According to said structure, the stray light prevention part is integrally formed with the optical system of the light guide type optical member. Therefore, the light guide type optical member and the stray light prevention unit can be assembled with high accuracy, and the number of parts can be reduced.

  In the optical pointing device of the present invention, it is preferable that a reflective film for reflecting the guided light is formed on the prism surface.

  According to said structure, since the reflecting film is formed in the surface of a prism, the angle range which can be reflected by a stray light prevention part can be expanded. Therefore, it is possible to reliably prevent the light emitted from the light source from becoming stray light without being reflected by the subject.

  In the optical pointing device of the present invention, the imaging reflecting portion may be a spherical surface, an aspherical surface, or a toroidal surface in which the curvature of the surface in the light guide direction and the curvature of the surface orthogonal to the light guide direction are different from each other. Good.

  According to said structure, an image formation reflection part has a spherical surface, an aspherical surface, or a toroidal surface. Accordingly, the curvature of the imaging reflecting portion is made spherical, non-spherical based on optical aberrations such as spherical aberration and coma aberration generated from the configuration of the optical system of the optical pointing device, and the distortion amount of the image projected on the image sensor. By appropriately setting the spherical surface or the toroidal surface, the optical characteristics of the light guide type optical member of the optical pointing device can be further improved.

  In the optical pointing device of the present invention, the optical path changing unit includes a prism that refracts reflected light from the subject, a reflective diffractive element that deflects reflected light from the subject, a reflective Fresnel lens, or a reflective hologram lens. You may be comprised from either.

  According to said structure, since an optical path conversion part is comprised from a prism (total reflection surface), an optical path conversion part can be comprised easily. Further, since the prism totally reflects incident light, the light utilization efficiency is highest with respect to optical path deflecting means such as a reflection type diffraction element, a reflection type Fresnel lens, or a reflection type hologram lens, which will be described later. As a result, the image projected onto the image sensor becomes brighter, and the S / N ratio can be improved.

  On the other hand, when the optical path conversion unit is composed of a reflection type diffractive element, a reflection type Fresnel lens, or a reflection type hologram lens (that is, the optical path that the optical path conversion unit deflects the direction of reflected light from the subject and guides it to the imaging means In the case of a deflection unit), the light use efficiency is lower than that of the optical path conversion unit by total reflection such as a prism. However, in particular, when the optical path deflecting unit is formed on the back surface of the light guiding type optical member, the light guiding type optical member including the function of the optical path deflecting unit can be formed without forming a concave portion therefor. Therefore, it is not necessary to form the concave portion as compared with the optical path changing portion by total reflection such as a prism in which the concave portion is formed, and therefore the thickness of the light guide type optical member can be made thin and uniform. Therefore, it is possible to reduce the thickness of the light guide optical member (that is, to reduce the thickness of the optical pointing device).

  In addition, when the optical path conversion unit is a reflection hologram lens, it can have a role of correcting aberrations that cannot be corrected by the imaging reflection unit. Thereby, the imaging performance of the imaging reflection unit is improved, and the image of the subject can be clearly captured by the imaging element.

  In the optical pointing device according to the aspect of the invention, it is preferable that the light guide type optical member includes a light shielding film that shields light from the outside in a surface region other than the contact surface with which the subject contacts.

  Light incident from the outside of the optical pointing device becomes disturbance light that is not necessary for the optical pointing device to detect the subject.

  According to the above configuration, the light shielding film is formed on the surface of the light guide type optical member on the subject side so as to avoid the contact surface with which the subject contacts. Thereby, the influence of disturbance light can be suppressed by the light shielding film. Therefore, the contrast of the image formed by the image sensor is improved.

  In the optical pointing device of the present invention, the imaging element is provided on a substrate and is resin-sealed with a transparent resin, and the light guide optical member is in contact with the surface and side surfaces of the transparent resin. It is preferable.

  According to said structure, the light guide type optical member is in contact with the transparent resin which seals the image pick-up element provided on the board | substrate. Thereby, the light guide type optical member can be arranged with high accuracy while maintaining the parallelism between the light guide type optical member and the image sensor. That is, each part and each element constituting the optical pointing device can be accurately arranged. Therefore, an optical pointing device with high subject detection accuracy can be realized.

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

  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 and the electronic apparatus according to the present invention, the light guide type optical member includes a contact surface that contacts the subject and a light guide light that is guided to the imaging reflection unit to the imaging element. The light guide in which the image reflection unit and the optical path conversion unit that converts the direction of the reflected light from the subject and guides it to the imaging reflection unit are formed integrally, and further, the light source and the image sensor are provided. The back surface of the mold optical member is provided with a stray light prevention unit that changes the path of light that is emitted from the light source and enters the image sensor without passing through the imaging reflection unit. Therefore, even in a thin optical pointing device, it is possible to provide an optical pointing device and an electronic device that can reduce the influence of stray light on image data captured by the image sensor.

It is sectional drawing which shows schematic structure of the optical pointing device in the 1st Embodiment of this invention. It is a perspective view which shows the structure of the back surface of the cover part in the optical pointing device of FIG. It is a figure which compares the stray light prevention effect of an optical pointing device, (a) is sectional drawing of the optical pointing device which does not have a stray light prevention structure, (b) is sectional drawing of the optical pointing device which has a stray light prevention structure is there. It is a figure which shows the transmittance | permeability and the reflectance with respect to the wavelength of the light in the reflecting film with which the optical pointing device of FIG. 1 is provided. It is a perspective view explaining the assembly method of the optical pointing device of FIG. It is sectional drawing which shows schematic structure of the optical pointing device in the 2nd Embodiment of this invention. It is a figure which shows the shape of the diffraction element and the groove pattern of a diffraction element in the optical pointing device of FIG. It is a figure which shows the shape of the diffraction element in the optical pointing device of FIG. It is sectional drawing which shows schematic structure of the optical pointing device in the 3rd Embodiment of this invention. It is a figure which shows the electronic device in the 4th Embodiment of this invention, and is a schematic diagram which shows the external appearance of the mobile telephone carrying the optical pointing device of this invention.

  Each embodiment of the present invention will be described by taking an optical pointing device using an LED as a light source module as an example. The optical pointing device of the present invention detects the movement of a subject by irradiating a subject such as a fingertip with light and receiving light reflected from the subject. Hereinafter, the configuration of the optical pointing device of each embodiment will be specifically described. Moreover, about the member which shows the same function and effect | action, the same code | symbol is attached | subjected and description is abbreviate | omitted.

[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic sectional view of an optical pointing device 30 according to the first embodiment. As shown in FIG. 1, the optical pointing device 30 includes a substrate portion 26 and a cover portion (light guide type optical member) 24. The substrate unit 26 includes a circuit board 21, a light source 16, an image sensor 15, and a transparent resin 20. The cover unit 24 includes a contact surface 11, a bending element 12 (an optical path conversion unit, a prism) that forms the inclined surface 13, an imaging element (imaging reflection unit) 14, and reflection surfaces 17 and 18 (an optical path conversion unit). The subject 10 in contact with the contact surface 11 of the cover unit 24 is a subject such as a fingertip, and is an object for which the optical pointing device 30 detects the movement of the fingerprint of the finger. Here, in order to make it easy to understand the state of the subject 10 with respect to the optical pointing device 30, the subject 10 is described as being small relative to the optical pointing device 30.

  Here, the thickness direction (vertical direction in FIG. 1) of the optical pointing device 30 is taken as the Z axis, and the width direction (horizontal direction in FIG. 1) of the optical pointing device 30 is taken as the Y axis. A direction from the lower part to the upper part of the optical pointing device 30 is a positive direction of the Z axis, and a direction from the light source 16 to the image sensor 15 is a positive direction of the Y axis. The positive direction of the Z axis is also called the vertical direction, and the positive direction of the Y axis is also called the horizontal direction. Although not shown, the depth direction of the optical pointing device 30 is the X axis, and the direction from the back side to the near side of the optical pointing device 30 shown in FIG. 1 is the positive direction of the X axis.

  First, the structure of the board | substrate part 26 is demonstrated. In the present embodiment, the light source 16 and the image sensor 15 are mounted on one circuit board 21. The light source 16 and the image sensor 15 are electrically connected to the circuit board 21 by wire bonding or flip chip mounting. A circuit is formed on the circuit board 21. The circuit controls the light emission timing of the light source 16 or receives an electrical signal output from the image sensor 15 to detect the movement of the subject. The circuit board 21 has a planar shape made of the same material, and is made of, for example, a printed board or a lead frame.

  The light source 16 emits light toward the contact surface 11 of the cover part 24. The light M emitted from the light source 16 is refracted by the bending element 12 of the cover portion 24 through the transparent resin 20, the traveling direction is changed, and reaches the contact surface 11. That is, the light M enters the contact surface from an oblique direction (at a certain incident angle with respect to the contact surface). As will be described later, since the cover portion 24 is made of a material having a refractive index larger than that of air, the light M that has reached the contact surface 11 partly touches the contact surface 11 when the subject 10 does not exist on the contact surface 11. The light is transmitted and the remaining part is reflected by the contact surface 11. At this time, when the incident angle of the light M with respect to the contact surface 11 satisfies the condition of total reflection, the light M does not pass through the contact surface 11 but is reflected by the contact surface 11 and travels into the cover portion 24. On the other hand, when the subject 10 is on the contact surface 11, the light M is reflected by the surface of the subject 10 in contact with the contact surface 11 and is incident on the cover unit 24. The light source 16 is realized by a light source such as an LED, for example, and is preferably realized by an infrared light emitting diode with high brightness.

  The image sensor 15 receives the light L reflected from the subject 10 irradiated by the light source 16, forms an image on the contact surface 11 based on the received light, and converts it into image data. Specifically, the image sensor 15 is an image sensor such as a CMOS or a CCD. The image sensor 15 includes a DSP (Digital Signal Processor: calculation unit) (not shown), and takes received light as image data into the DSP. The image sensor 15 continues to capture images on the contact surface 11 at regular intervals in accordance with instructions from the circuit board 21.

  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. In the DSP, the image sensor 15 compares the values of the same portion of the captured image data with the immediately preceding image data, and calculates the movement amount and movement direction of the subject 10. That is, when the subject 10 on the contact surface 11 moves, the captured image data is image data indicating a value deviated from the image data captured immediately before by a predetermined amount. In the DSP, the image sensor 15 calculates the movement amount and movement direction of the subject 10 based on the predetermined amount. The image sensor 15 outputs the calculated movement amount and movement direction to the circuit board 21 as electric signals. The DSP may be included in the circuit board 21 instead of in the image sensor 15. In that case, the image sensor 15 transmits the captured image data to the circuit board 21 in order.

  To summarize the processing of the image sensor 15, 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 image sensor 15 captures an image of the surface of the subject 10 in contact with the contact surface 11. For example, when the subject 10 is a fingertip, the image sensor 15 captures an image of a fingertip fingerprint. Here, since the image data captured by the image sensor 15 is different from the image data when the subject 10 is not on the contact surface 11, the DSP of the image sensor 15 has 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, the movement amount and movement direction of the subject 10 are calculated compared with the image data captured immediately before by the DSP, and a signal indicating the calculated movement amount and movement direction is transmitted to the circuit board 21. .

  The light source 16 and the imaging element 15 are resin-sealed with a transparent resin 20 made of a translucent resin. The shape of the transparent resin 20 is a substantially rectangular parallelepiped. The bottom surface of the transparent resin 20 is in close contact with and in contact with the upper surface of the circuit board 21, and concave portions that are in close contact with the light source 16 and the image sensor 15 are formed. As the translucent resin, for example, a thermosetting resin such as a silicone resin or an epoxy resin, or a thermoplastic resin such as acrylic or polycarbonate is used.

  Thus, since the light source 16 and the image sensor 15 mounted on the circuit board 21 are respectively sealed with the transparent resin 20, the circuit board 21, the light source 16, the image sensor 15, and the transparent resin 20 are integrated. A substrate portion 26 is formed. Therefore, the number of parts of the optical pointing device 30 can be reduced, and the number of assembly processes can also be reduced. Accordingly, the manufacturing cost of the optical pointing device 30 can be reduced, and the optical pointing device 30 with high subject detection accuracy can be realized. Next, the structure of the cover part 24 is demonstrated. The cover part 24 protects each part and each element constituting the optical pointing device 30 such as the light source 16 and the imaging element 15. The cover part 24 is located on the upper side of the substrate part 26 and is in close contact with the side surface and the upper surface of the substrate part 26. The surface of the cover 24 that is on the negative side of the Z-axis and that is not exposed to the outside when mounted on the substrate 26 and formed as the optical pointing device 30 is referred to as the back of the cover 24. . That is, some of the contact surfaces (contact surfaces 24A, 24B, 24C) on the back surface of the cover portion 24 are in close contact with and in contact with the side surface and the upper surface of the substrate portion 26. The bottom surface (contact surface 24 </ b> C) of the cover portion 24 forms the same plane as the bottom surface of the substrate portion 26. The upper surface of the cover part 24 is parallel to the bottom surface (contact surface 24C) of the cover part 24 and the bottom surface of the substrate part 26, and both side surfaces of the cover part 24 are the upper surface of the cover part 24 and the cover part. It is formed by a surface having an angle with respect to the bottom surface (contact surface 24 </ b> C) of 24 and the bottom surface of the substrate portion 26. That is, as shown in FIG. 1, the optical pointing device 30 has a trapezoidal shape in the cross-sectional view. However, the shape is not limited to this, and the side surface may be perpendicular to the bottom surface.

  A flange 25 is provided in the vicinity of the bottom of the side surface of the cover, and the optical pointing device of the present invention is mounted on the device and is pushed from the contact surface 11 of the cover 24 to the negative side of the Z axis by a subject such as a finger. In this case, the force generated in the positive direction of the Z-axis by a leaf spring-shaped contact switch provided on the bottom surface of the substrate portion 26 (not shown) is regulated at a certain position to ensure a certain stroke amount necessary as a pushbutton switch. Used for.

  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 an upper surface of the cover portion 24 and is located above the light source 16.

  The bending element (prism) 12 is located above the light source 16 and below the contact surface 11, and forms a concave portion on the back surface of the cover portion 24 that is located on the back surface of the cover portion 24 and not in contact with the substrate portion 26. To do. The bending element 12 is formed with an inclined surface 13, and a narrow angle formed by the inclined surface 13 and the upper surface of the cover portion 24 is defined as an inclination angle θ. The bending element 12 refracts the light M emitted from the light source 16 on the inclined surface 13 and converts the path of the light M so as to go to the subject 10. Further, the bending element 12 totally reflects the light L reflected from the subject 10 by the inclined surface 13, and converts the path of the light L in the positive direction of the Y axis inside the cover portion 24. . The light L reflected from the subject 10 that has been totally reflected by the inclined surface 13 is directed to a reflection surface 17 described later. Thus, the inclined surface 13 of the bending element 12 transmits the light M and totally reflects the light L. Therefore, a material having a refractive index higher than the refractive index of the space above the light source 16 and between the cover portion 24 and the substrate portion 26 is used for the cover portion 24. For example, the cover 24 may be made of an air layer using a visible light absorption type polycarbonate resin or acrylic resin having a refractive index of about 1.5. That is, an aluminum reflective film or the like is not deposited on the inclined surface 13 of the bending element 12 in order to totally reflect the light L.

  The imaging element (lens) 14 reflects the reflected light L from the subject 10 and forms an image of the subject 10 on the imaging element 15. The imaging element 14 is located above the image sensor 15 and on the positive side of the Y axis with respect to the image sensor 15, and is located on the back surface of the cover portion 24 that is not in contact with the substrate portion 26. A recess is formed. The imaging element 14 is formed with a toroidal surface having different curvatures in two orthogonal directions. The imaging element 14 reflects the light L reflected by the toroidal surface so as to form an image on the imaging element 15. In order to efficiently reflect the light L at the imaging element 14, a reflective film of metal (for example, aluminum, nickel, gold, silver, dielectric dichroic film, etc.) is deposited on the toroidal surface of the imaging element 14. . In the above description, the imaging element 14 is formed with a toroidal surface, but instead, for example, a reflector such as a spherical surface or an aspherical surface that can form an image on the imaging element 15. It is possible to use.

  A stray light prevention prism for preventing stray light (stray light prevention) having a fine prism structure in the positive direction of the Y-axis from the end of the total reflection surface of the bending element (prism) 12 on the bottom surface (contact surface 24C) side of the cover portion 24. Part) 19A is formed. FIG. 2 is a perspective view from the bottom surface (contact surface 24C) side of the cover portion 24. Similarly, an aperture 19B having a fine prism structure is formed on both sides of the imaging element (lens) 14 in the X-axis direction. Is formed. These effects will be described with reference to FIG. FIG. 3 is a cross-sectional view of an optical pointing device schematically showing the effect of the stray light preventing structure.

  3A shows the optical pointing device 300 when the stray light preventing prism 19A is not provided in the optical pointing device 30 of FIG. 1, and FIG. 3B shows the optical pointing device 30 of FIG. The aperture 19B is also a structure for guiding stray light / disturbance light from outside the effective diameter in the X-axis direction of the imaging element 14 in a certain direction without entering the imaging element 15 using the same fine structure. Since the operation and effect are the same as the stray light prevention prism 19A, only the stray light prevention prism 19A will be described here. On the other hand, the light from the light source 16 is emitted with a certain spread from the light emitting point of the light source. Of the emitted light, the light M is scattered and reflected by the subject 10, becomes reflected light L, and enters the image sensor 15. However, light N1 and light N2 other than M are incident on the image sensor 15 as stray light without passing through the optical path of the imaging element 14 as shown in FIG. 3A where the stray light prevention prism is not formed. To do. In this case, the signal component obtained by subjecting the image picked up on the image pickup device 15 by the light passing through the optical path L to the image processing by the circuit board 21 can obtain signal information regarding the amount and direction of movement of the subject 10. On the other hand, a similar image by light passing through the optical path N1 and the optical path N2 can only obtain an image that does not move even if the subject 10 moves, so that not only signal information can be obtained but also a moving image. Since the images that do not move overlap and hide the movement of the images, accurate signal information cannot be obtained. (Hereinafter, light passing through the optical path L from which signal information can be obtained is referred to as signal light, and light other than signal light is referred to as noise light. In addition, noise light generated by a light source inside the optical pointing device is incident as stray light or from outside the optical pointing device. On the other hand, in FIG. 3B provided with the stray light preventing prism 19A, the stray light N1 and N2 generated in FIG. Since it changes to N2 ′ and is reflected outside the cover portion 24 and absorbed by the circuit board 21 or the like, it does not become noise light. The stray light prevention prism 19A and the aperture 19B are effective in addition to the light at the angles N1 and N2 of the light source 16 shown in FIG. 3, and not only the stray light from the light source 16 provided in the optical pointing device 30. It is also effective for disturbance light from outside the device.

  The fine prism structures of the stray light preventing prism 19A and the aperture 19B may be appropriately set so that the size of one side is about 30 to 100 μm and the forming angle is not in the undercut direction of the molding die. Although not shown in the drawing, a prism (aluminum, nickel, gold, silver, dielectric dichroic film, etc.) deposited film is provided on the stray light preventing prism 19A and the aperture 19B to give reflection characteristics. The stray light coming from an angle other than the total reflection angle is reflected in the opposite direction to the image sensor 15, or a light-shielding film (for example, paint or ink mixed with carbon black is formed by inkjet or printing) is used in place. By absorbing stray light, it is possible to enhance the stray light countermeasure effect. It is also possible to hybridize the fine prism structure for stray light countermeasures with the vapor deposition film or the light shielding film. For example, when there is a total reflection surface in the immediate vicinity of a place where it is desired to take countermeasures against stray light, stray light from a small part that is not covered becomes a problem even if the majority is covered with a vapor deposition film or a light shielding film. This is because the formation accuracy of the film is as low as 0.5 mm to 1 m, and it is necessary to enlarge the mask so that the film is not attached to the total reflection surface. Since the value is one digit or more (about 10 μm), it is sufficiently possible to form a fine prism structure in a portion where this film cannot be formed.

  Further, even if the concave / convex dimple structure other than the prism is used as the stray light prevention structure, the incident light is scattered on the spot, but the strong light does not reach the image pickup device 15, so that the stray light prevention action is achieved. Is enough.

  The reflecting surface 17 reflects the light L so that the light L totally reflected by the inclined surface 13 is incident on the imaging element 14 and the light L reflected from the imaging element 14 is incident on the imaging element 15. It is. The reflection surface 17 is located above the image sensor 15 and on the upper surface of the cover portion 24. The reflection surface 17 is formed by depositing a reflection film on the upper surface of the cover portion 24. Since the reflective film forming the reflective surface 17 is exposed to the outside and can be seen well by the user, it is desirable to make the film as inconspicuous as possible in appearance. 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 reflective film forming the reflective surface 17 is an infrared reflective film having the characteristics shown in FIG. If it is. FIG. 4A is a diagram showing the transmittance and reflectance at each wavelength, where the horizontal axis represents wavelength (nm) and the vertical axis represents transmittance and reflectance (%). The dotted line in the figure indicates the transmittance, and the solid line indicates the reflectance (the same applies to FIGS. 4B and 4C). As a specific example of the reflecting film, the reflecting film forming the reflecting surface 17 reflects infrared light having a wavelength band of 800 nm or more irradiated from the light source 16 and transmits light having a visible wavelength band of 800 nm or less. That's fine. As described above, the reflected light L from the subject 10 is efficiently reflected by appropriately setting the wavelength of the light emitted from the light source 16 and the reflectance and transmittance characteristics of the reflecting film forming the reflecting surface 17. And the reflective surface 17 which is not conspicuous in appearance can be formed.

  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 24 is preferably formed of a material having the characteristics shown in FIG. . Specifically, the material of the cover portion 24 may be a visible light absorption type polycarbonate resin or acrylic resin that transmits only infrared light. By forming the cover part 24 with such a material, visible light components can be blocked by the cover part 24 from unnecessary light entering from the outside of the cover part 24. As described above, by forming the reflection surface 17 that reflects infrared light, the infrared light component of the unnecessary light can be blocked by the reflection surface 17. By blocking unnecessary light incident on the optical pointing device 30, malfunction due to the unnecessary light can be prevented.

  Furthermore, when coloring the surface of the cover unit 24, which is the surface of the optical pointing device 30, for example, a predetermined as shown in FIG. 4C is formed on the upper surface of the cover unit 24 and the upper surface of the reflection surface 17. What is necessary is just to coat with the material which reflects only the wavelength band of color (green in the example of illustration), and permeate | transmits other wavelengths. By coating the upper surface of the cover portion 24 and the upper surface of the reflecting surface 17 with a material having such characteristics, a desired color is applied to the surface of the optical pointing device 30 without impairing the optical characteristics of the optical pointing device 30. Can be attached.

  The reflecting surface 18 reflects the light L reflected from the imaging element 14 and reflected by the reflecting surface 17 toward the reflecting surface 17 again. The reflection surface 18 is located above the image sensor 15 and on the positive side of the Y axis from the image sensor 15, and is located on the back surface of the cover portion 24. The reflection surface 18 is formed by depositing a reflection film on the back surface of the cover portion 24. The reflective film forming the reflective surface 18 is preferably one that efficiently reflects light. For example, the reflecting surface 18 is formed by vapor-depositing a metal such as aluminum, nickel, gold, silver, or a dielectric dichroic film.

  As described above, in the optical pointing device 30 of the present embodiment, the cover portion 24 is assembled above the substrate portion 26 with the transparent resin 20 side surface and the upper surface sealing the imaging element 15 in the substrate portion 26 as a reference. Yes. In the cover portion 24, contact surfaces 24 A and 24 B serving as a reference for making a decision on the transparent resin 20 of the substrate portion 26 are integrated with the contact surface 11, the bending element 12, the imaging element 14, and the flange 25. Is formed. Therefore, the contact surfaces 24A and 24B, the contact surfaces 11, the bending element 12, the imaging element 14, and the flange 25 are arranged with high mold tolerance.

  Therefore, the contact surfaces 24A and 24B of the cover part 24 are brought into contact with the side surfaces and the upper surface of the transparent resin 20 of the substrate part 26, whereby the positional relationship with the cover part 24 can be arranged with high accuracy. Therefore, since each unit and each element constituting the optical pointing device 30 can be arranged with high accuracy, the optical pointing device 30 with high detection accuracy of the subject 10 can be realized.

  Here, the path through which the light emitted from the light source 16 reflects the subject 10 and enters the image sensor 15 will be described again. First, the light M emitted from the light source 16 is refracted and transmitted by the inclined surface 13 of the bending element 12 and reaches the contact surface 11. When the subject 10 is on the contact surface 11, the light M emitted from the light source 16 is scattered and reflected on the surface of the subject 10 in contact with the contact surface 11. The light L reflected by the surface of the subject 10 is totally reflected by the inclined surface 13 of the bending element 12, and the path changes in the positive direction of the Y axis. The light L totally reflected by the inclined surface 13 is reflected by the reflecting surface 17 and reaches the imaging element 14. Then, the light L is reflected back by the imaging element 14, is reflected one after another by the reflecting surface 17, the reflecting surface 18, and the reflecting surface 17 and enters the imaging device 15.

  By adopting such an optical system, even if the optical path length of the optical system is increased and aberrations are suppressed, the length of the cover 24 in the Y-axis direction can be made smaller and smaller than the optical path length. It is possible to reduce the size.

  As described above, in the present embodiment, the contact surface 11, the bending element 12, the imaging element 14, the stray light prevention prism 19 </ b> A, and the aperture 19 </ b> B are integrally formed with the cover portion 24. Therefore, the number of parts of the optical pointing device 30 can be reduced, and the number of assembly processes can also be reduced. In addition, by forming a mold for forming the cover portion 24 with high accuracy, the inclined surface 13 and the imaging element 14, the stray light prevention prism 19A and the aperture 19B of the bending element 12 can be manufactured with high accuracy, and The positional relationship among the contact surface 11, the bending element 12, the imaging element 14, the stray light prevention prism 19A and the aperture 19B can also be arranged with mold accuracy. Accordingly, the manufacturing cost of the optical pointing device 30 can be reduced, and the optical pointing device 30 with high subject detection accuracy can be realized.

  Further, when assembling the contact surface 11, the bending element 12, and the imaging element 14 as separate parts, shapes such as an abutting surface for assembly and a fitting shape are required. Since it cannot be formed, a separate aperture such as a light-shielding sheet and stray light prevention means are required, so a contact surface for assembling them and a shape such as a fitting shape are also required, and a margin for adjusting the relative positional relationship between them. It is necessary to ensure. When integrated, the above shape is not necessary, and if there is a minimum required optical surface, it is not necessary to secure an adjustment margin, and the contact surface 11, the bending element 12 and the imaging element 14, the stray light prevention prism 19A, and the aperture The thickness of the cover part 24 including 19B can be reduced. Therefore, the thickness of the optical pointing device 30 can be reduced.

  In the present embodiment, the cover portion 24 is assembled above the substrate portion 26 with reference to the side surface and the upper surface of the transparent resin 20 of the substrate portion 26. This will be described with reference to FIG. FIG. 5 is a schematic diagram for explaining how to assemble the optical pointing device according to the first embodiment of the present invention. The cover portion 24 includes contact surfaces 24A, 24B, and 24C that serve as a reference for making a decision on the transparent resin 20 of the substrate portion 26. The contact surface 11, the bending element 12, the imaging element 14, and the stray light prevention prism 19A. The aperture 19B and the flange 25 are integrally formed. Therefore, the contact surfaces 24A, 24B, and 24C, the contact surfaces 11, the bending element 12, the imaging element 14, the stray light prevention prism 19A, the aperture 19B, and the flange 25 are arranged with high precision with mold tolerances. . The cover portion 24 is arranged as shown by an arrow P in FIG. 5, and the contact surfaces 24A, 24B, and 24C of the cover portion 24 are brought into contact with the side surface and the upper surface (surface) of the transparent resin 20 of the substrate portion 26. The positional relationship with the cover part 24 can be arranged with high accuracy. Therefore, since each part and each element constituting the optical pointing device 30 can be arranged with high accuracy, the optical pointing device 30 with high detection accuracy of the subject 10 can be realized.

  Further, a light-shielding resin may be resin-sealed on the side surface of the transparent resin 20 and the upper surface excluding the lens portion. Further, a light shielding resin may be resin-sealed on the side surface of the transparent resin 20 and on the upper surface of the transparent resin 20 excluding a portion where the reflected light L from the subject is transmitted. As the light-shielding resin, for example, a thermosetting resin such as a silicone resin or an epoxy resin, or a thermoplastic resin such as acrylic or polycarbonate is used, similarly to the light-transmitting resin. However, unlike the light-transmitting resin, the light-blocking resin includes carbon black. In this way, by sealing the light-shielding resin around the transparent resin 20, the light emitted from the light source 16 is reflected directly or at a place other than the subject 10 and enters the image sensor 15. Can be prevented. It is possible to prevent so-called stray light that is not reflected light L from the subject 10 from entering the image sensor 15. Therefore, malfunction of the optical pointing device 30 due to stray light can be prevented, and the subject 10 can be detected with high accuracy.

  As described above, in the optical pointing device 30 of the present embodiment, the light emitted from the light source 16 does not pass through the imaging element 14 on the back surface (the surface facing the light source 16 and the image sensor 15) of the cover portion 24. A stray light prevention prism 19A that changes the path of light incident on the image sensor 15 is provided. In other words, the cover 24 is provided with a countermeasure (stray light countermeasure) against the light emitted from the light source 16 and directly incident on the imaging element 15 without being reflected by the subject 10. Thus, when light that has not been reflected by the subject 10 that causes stray light among the light emitted from the light source 16 reaches the stray light prevention prism 19A, the path is changed when the light is emitted from the stray light prevention prism 19A. Therefore, the light emitted from the light source 16 can be prevented from becoming stray light without being reflected by the subject 10.

  Further, since the stray light preventing prism 19 </ b> A is formed on the back surface of the cover portion 24, stray light can be prevented even in the thin optical pointing device 30.

  Therefore, even in a thin optical pointing device, it is possible to provide the optical pointing device 30 that can reduce the influence of stray light on the image data captured by the image sensor 15.

  In addition, in the optical pointing device 30, the contact surface 11, the bending element 12, the imaging element 14, the stray light preventing prism 19A, and the aperture 19B are integrally formed with the cover portion 24. That is, an optical system that is an essential component of the optical pointing device 30 is integrally formed. As a result, even if the optical path length of the optical system is increased and aberrations are suppressed, the length of the cover portion 24 in the vertical direction can be reduced as compared with the optical path length. Therefore, the optical pointing device 30 can be further reduced in size and thickness. Moreover, by integrally molding, the cover portion 24 can be assembled with high accuracy and the number of parts can be reduced.

[Second Embodiment]
A second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a schematic sectional view of an optical pointing device 30a according to the second embodiment. In the second embodiment, a diffractive element 12 ′ is arranged instead of the bending element 12 that totally reflects the reflected light L in the horizontal direction in the first embodiment. Hereinafter, differences from the first embodiment due to the arrangement of the diffraction element 12 ′ in the second embodiment will be described. In the second embodiment, the description of the same configuration as in the first embodiment is omitted.

  As shown in FIG. 6, in the substrate portion 26, the transparent resin 20 that seals the light source 16 is such that the negative side surface of the Y axis is not flush with the side surface of the circuit board 21, and the negative side surface of the Y axis is It is located on the positive side of the Y axis from the side surface of the circuit board 21. The light M emitted from the light source 16 is transmitted and refracted on the back surface of the cover portion 24 via the lens portion 27 of the transparent resin 20 and reaches the contact surface 11.

  The cover 24 includes the contact surface 11, the diffraction element 12 ′, the imaging element 14, the stray light prevention prism 19 </ b> A, the aperture 19 </ b> B, and the reflection surfaces 17 and 18. The cover portion 24 is located above the substrate portion 26 and is in close contact with the X-axis positive side surface, the Y-axis positive side surface, and the upper surface of the transparent resin 20 that seals the imaging device 15 and the light source 16. Touching.

  The diffractive element 12 ′ is located above the light source 16 and below the contact surface 11 and in a portion that does not contact the substrate portion 26 on the back surface (contact surface 24 </ b> C) of the cover portion 24. The diffractive element 12 ′ reflects the light L reflected from the subject 10, and converts the path of the light L in the positive direction of the Y axis inside the cover portion 24. The light L reflected from the subject 10 and reflected by the diffraction element 12 ′ travels toward the reflecting surface 17.

  A specific shape of the diffraction element 12 'will be described with reference to FIG. FIG. 7A is a schematic configuration diagram showing a cross-sectional shape of the diffraction element 12 ′. The diffractive element 12 'is a reflective diffractive element that uses + 1st order reflected diffracted light. As for the shape of the diffractive element 12 ′, for example, it is desirable that the cross-sectional shape as shown in FIG. By using the blazed diffractive element 12 ′ shown in FIG. 7A, the light use efficiency can be improved and the 0th order light, the −1st order light, and the higher order diffracted light that become stray light can be suppressed. Therefore, in the optical pointing device 30a, it is possible to prevent the imaging performance of the optical system from deteriorating.

  In order to improve the reflectance, a reflective film al (for example, aluminum, silver, gold, dielectric dichroic film, etc.) is vapor-deposited on the outer surface (surface on the negative side of the Z axis) of the diffraction element 12 ′. It is desirable. Here, as shown in FIG. 7A, the blazed groove depth (length in the Z direction) of the diffractive element 12 'is t. The groove depth t is desirably a depth that maximizes the + 1st order diffraction efficiency. For example, when the refractive index n of the cover 24 and the wavelength of light emitted from the light source 16 are λ, it is desirable to set t = λ / (2n).

  Further, the blazed groove pattern of the diffractive element 12 'has a straight equal pitch as shown in FIG. 7B, and is desirably as fine as possible in order to increase the diffraction angle as much as possible. However, in terms of manufacturing, it is most advantageous in terms of cost to form and mold the groove by cutting using a cutting tool for the mold. Therefore, in consideration of the range in which the grooves can be accurately manufactured by cutting, it is desirable to design the groove pitch of the diffractive element 12 ′ between 0.8 to 3.0 μm.

  Further, in order to improve the imaging performance for capturing the image of the subject 10 projected onto the image sensor 15, the groove pattern of the diffraction element 12 ′ is curved as shown in FIG. Distortion can be corrected. Further, as shown in FIG. 7D, the groove pitch of the diffractive element 12 ′ is not an equal pitch but a pattern in which the pitch gradually changes, and the diffractive element 12 ′ is designed to have a lens effect in a certain direction. You may do it. In this case, it is possible to correct aberration that occurs due to the difference in focal length between the X-axis direction and the Y-axis direction on the image sensor 15.

  Further, as shown in FIG. 5E, both the image distortion and astigmatism (astigmatism) can be corrected by making the groove pattern of the diffractive element 12 'a curved and unequal pitch pattern. .

  As another specific example of the diffraction element 12 ', a reflection type Fresnel lens may be used for the diffraction element 12'. A specific shape of the Fresnel lens is shown in FIG. FIG. 8 is a schematic configuration diagram showing a cross-sectional shape of a diffraction element 12 ′ that is a Fresnel lens, as in FIG. 7A. As shown in the figure, the cross-sectional shape of the Fresnel lens is a blaze shape. In order to improve the reflectance, it is desirable that a reflective film al (for example, aluminum, silver, gold, dielectric dichroic film, etc.) is deposited on the outer surface of the diffraction element 12 '. When a Fresnel lens is used for the diffractive element 12 ′, the thickness of the cover portion 24 can be made uniform compared to the case where a prism or a bulk lens is formed on a part of the cover portion 24. Therefore, it is possible to reduce the thickness of the optical pointing device 30a while increasing the strength of the cover portion 24.

  Further, if a hologram lens is used for the diffraction element 12 ′, aberrations that cannot be corrected by a normal lens can be corrected, so that the imaging performance is improved, and the image of the subject 10 is projected clearly on the imaging element 15. Can do.

  As described above, when the diffractive element 12 ′ is used to reflect the light L reflected from the subject 10 in the horizontal direction, compared with the case where the bending element (prism) 12 is formed in the cover part 24, The thickness can be made uniform. Therefore, it is possible to reduce the thickness while increasing the strength of the cover portion 24. In addition, the light irradiated from the light source 16 can be irradiated to the contact surface 11 with uniform light intensity.

  Further, in the conventional optical pointing device that bends the reflected light L from the subject 10 in the horizontal direction (for example, the configuration of Patent Document 1 above), the size of the bending element 12, particularly the length in the Z-axis direction, is the same as that of the optical pointing device. It greatly affects the thickness. That is, in order to design the optical pointing device thin, it is important to reduce the length of the bending element 12 in the Z-axis direction. However, the size of the bending element 12 cannot be designed freely, and the size of the bending element 12 depends on the size of the contact surface 11. And in order to detect the pattern on the contact surface 11, the contact surface 11 must have a certain amount of area. Therefore, if the area of the contact surface 11 is to be secured, the bending element 12 inevitably increases, and the thickness of the optical pointing device 30 (size in the Z-axis direction) cannot be reduced.

  In the second embodiment, the optical pointing device 30a is made thinner than the first embodiment by using a diffractive element 12 'that can be smaller in length in the Z-axis direction than the bending element 12 instead of the bending element 12. Can be achieved.

  In the second embodiment, similarly to the method shown in the first embodiment, a cover is provided above the substrate portion 26 with reference to the side surface and the upper surface of the transparent resin 20 that seals the imaging element 15 in the substrate portion 26. The part 24 is assembled. That is, a part of the contact surface (contact surfaces 24A, 24B, 24C) on the back surface of the cover portion 24, the side surface on the positive side of the X axis in the transparent resin 20 that seals the image sensor 15 and the light source 16, and the Y axis The cover portion 24 is assembled above the substrate portion 26 with reference to the positive side surface and the upper surface. Therefore, the positional relationship between the substrate part 26 and the cover part 24 can be arranged with high accuracy. Therefore, since each part and each element constituting the optical pointing device 30a can be arranged with high accuracy, the optical pointing device 30a with high detection accuracy of the subject 10 can be realized.

[Third Embodiment]
A third embodiment of the present invention will be described with reference to FIG. FIG. 9 is a schematic sectional view of an optical pointing device 30b according to the third embodiment. In the third embodiment, in addition to the first and second embodiments, a diffractive element 12 ′ is disposed instead of the bending element 12 that totally reflects the reflected light L of the optical pointing device in the horizontal direction. Hereinafter, differences from the first embodiment due to the arrangement of the diffraction element 12 ′ in the third embodiment will be described. In the third embodiment, the same configuration as that of the first embodiment will be described for the sake of explanation. However, the changed portion and the effect are the same as those of the second embodiment, and the same effect is obtained. The description of the same parts as those in the first embodiment is omitted.

  As illustrated, in the optical pointing device 30b, light shielding films 28A and 28B that shield light from the outside of the device are formed on the contact surface 11 of the cover portion 24. The window area indicated by P in the figure is a portion where the light shielding film is not formed, the subject 10 is in contact with the contact surface 11 of the cover 24, and the light from the light source 16 is shielded by the light shielding films 28A and 28B. This is an area where the subject 10 can be reached without being done.

  In the light coming from the outside of the pointing device 30b of the present embodiment, the light from other than the object surface on the cover contact surface that can obtain good characteristics in the imaging element 14 is multiple-reflected inside the cover unit 24, and the image sensor 15, the signal light passing through the optical system including the imaging element 14 of the cover 24 becomes disturbance light and the contrast of the image captured by the imaging element 15 is lowered. Of course, even when the subject 10 is a finger even when the light comes from outside the apparatus, the light transmitted through the finger enters the cover portion 24 from the contact surface and passes through the optical system including the imaging element 14. However, since the amount of disturbance light is larger, the contrast of the image is lowered as a result.

  However, according to the above configuration, since the influence of the disturbance light can be suppressed and only the signal light can be enhanced, the contrast of an image photographed by the imaging element is improved.

  The light shielding films 28A and 28B may be reflective films that specifically reflect disturbance light (for example, aluminum, silver, gold, dielectric dichroic film, etc.), and absorption films that absorb disturbance light in situ (for example, , Paint or ink mixed with carbon black). In the case of a vapor deposition film, vapor deposition may be performed by masking the window area, and in the case of an absorption film, it may be formed by ink jet or pad printing.

  Since the flange 25 is disposed inside the housing of the device to be mounted, the area for forming the light-shielding film may be formed in the positive direction of the Z axis with respect to the flange 25 protruding from the device housing. Further, the casing of the device has a thickness, and disturbance light is shielded by the thickness. Therefore, the light shielding film 28B is not always necessary, and measures such as forming only the light shielding film 28A may be appropriately taken.

[Fourth Embodiment]
Finally, an electronic device equipped with an optical pointing device will be described with reference to FIG. FIG. 10 is a diagram illustrating an appearance of the mobile phone 100 on which the optical pointing device 107 is mounted. 10A is a front view of the mobile phone 100, FIG. 10B is a rear view of the mobile phone 100, and FIG. 10C is a side view of the mobile phone 100. Although FIG. 10 shows an example in which the electronic device is a mobile phone, the present invention is not limited to this. The electronic device may be, for example, a PC (particularly a mobile PC), a PDA, a game machine, a remote controller such as a television, or the like.

  As shown in FIG. 10, the mobile phone 100 includes a monitor-side casing 101 and an operation-side casing 102. The monitor-side casing 101 includes a monitor unit 105 and a speaker unit 106, and the operation-side casing 102 includes a microphone unit 103, a numeric keypad 104, and an optical pointing device 107. Any of the optical pointing devices 30, 30a, 30b, and 30c described in the first to fourth embodiments can be applied to the optical pointing device 107 mounted on the mobile phone 100.

  In the present embodiment, the optical pointing device 107 is arranged on the upper part of the numeric keypad 104 as shown in FIG. 10A. However, the arrangement method and the direction of the optical pointing device 107 are not limited thereto. It is not done.

  The speaker unit 106 outputs audio information to the outside, and the microphone unit 103 inputs audio information to the mobile phone 100. The monitor unit 105 outputs video information. In the present embodiment, the monitor unit 105 displays input information from the optical pointing device 107.

  Note that, as shown in FIGS. 10A to 10C, the cellular phone 100 according to the present embodiment includes an upper casing (monitor-side casing 101) and a lower casing (operation-side casing 102). As an example, a so-called foldable mobile phone 100 is connected to each other via a hinge. Since the folding type is mainstream as the cellular phone 100, the folding type cellular phone is given as an example in this embodiment, and the cellular phone 100 on which the optical pointing device 107 can be mounted is foldable. It is not limited.

  In recent years, a folding mobile phone 100 having a thickness of 10 mm or less in a folded state has appeared. If the portability of the mobile phone 100 is taken into consideration, its thickness is an extremely important factor. In the operation-side casing 102 shown in FIG. 10, components that determine the thickness of the operation-side casing 102 except for an internal circuit board (not shown) are a microphone unit 103, a numeric keypad 104, and an optical pointing device 107. Among these, the thickness of the optical pointing device 107 is the largest, and the thinning of the optical pointing device 107 directly leads to the thinning of the mobile phone 100. Therefore, the optical pointing device of the present invention that can be thinned as described above is a preferred invention for an electronic device that needs to be thinned, such as the cellular phone 100.

  In each of the above-described embodiments, the optical pointing device including the light source 16 has been described. However, instead of the light source 16, even in the case of external light such as sunlight, an optical pointing device that operates without degrading performance can be obtained by the configuration of the present invention.

  Further, in each of the above-described embodiments, the optical pointing device using the cover portion 24 (light guide type optical member) has been described. However, the same effect can be obtained by providing the stray light preventing unit of the present invention in a conventional optical pointing device (for example, the configuration of Patent Documents 2 and 3) that does not use the cover unit 24.

  The present invention can also be expressed as follows.

  An optical pointing device according to the present invention comprises an imaging means for forming an image of scattered light from a subject, and receiving the scattered light from the subject and continuously taking images of the surface of the subject at regular intervals. An image sensor that captures an image as image data, and a calculation unit that calculates the moving direction and amount of movement of the subject by comparing the image data captured by the image sensor with the image data captured by the image sensor immediately before, An optical pointing device comprising a cover member that covers the imaging means, the imaging device, and the calculation unit, wherein the cover member has at least a contact surface that contacts the subject, and the imaging means; An optical path deflecting unit that deflects the direction of scattered light from the subject incident from the contact surface and guides it to the imaging unit, a stray light preventing unit that prevents stray light, and an imaging unit. Apertures to be given may be integrally formed.

  According to the above configuration, since the cover portion, the optical path deflecting unit, the imaging unit, the stray light preventing unit, and the aperture are integrally formed, the number of components constituting the optical pointing device can be reduced. it can. Therefore, the number of assembling steps can be reduced in the manufacturing process of the optical pointing device. Therefore, it is possible to suppress an assembly error that occurs when assembling each component. In addition, by creating a mold for molding the cover part with high precision, the shape of the optical path deflecting means, imaging means, stray light preventing means and the aperture itself can be manufactured with high precision, and the contact surface can be bent. The positional relationship between the element and the imaging element and the positional relationship between the imaging means and the aperture can be arranged with high accuracy without variation. Accordingly, the manufacturing cost of the optical pointing device can be reduced, the detection accuracy of the subject is high, and the S / N (Signal / Noise: Signal here means from the contact surface to the optical path deflecting means and the imaging means. This is an effect that it is possible to realize an optical pointing device having a high ratio of scattered light components from the subject incident on the image sensor through the noise, and Noise being an unnecessary light component incident on the image sensor through other optical paths. Play.

  Therefore, according to the above configuration, it is possible to reduce the manufacturing cost of the optical pointing device and to realize an optical pointing device with high subject detection accuracy.

  Further, the stray light preventing means and the aperture of the optical pointing device according to the present invention may have a fine structure.

  According to said structure, a stray light prevention means and an aperture can be integrally formed with a metal mold | die etc. with the said optical path deflection | deviation means and the said image formation means. The stray light preventing means and the aperture can be formed integrally with the cover member by the technique of insert molding, but separate parts are required, and the position of these parts also shifts during insert molding. However, if it has a fine structure, high-precision arrangement is possible without the need for separate parts.

  Further, the stray light preventing means and the aperture fine structure of the optical pointing device according to the present invention may be a prism structure.

  As the fine structure of the stray light prevention means and aperture, a fine uneven dimple structure is also effective, but in the dimple structure, the stray light component may be scattered there and reflected again on another surface of the cover part and incident on the image sensor. Is not small. However, according to the above configuration, since the planar portion of the prism reflects stray light in a specific direction, it is less likely to be reflected again on another surface of the cover portion and enter the imaging device. Will improve.

  Further, the stray light preventing means and the aperture of the optical pointing device according to the present invention may be provided with a reflection performance by a deposited film obtained by depositing a metal or a dielectric.

  The incident angle of the stray light incident on the stray light prevention means and the aperture is not constant, and it is incident from various directions, but when the reflection performance is not given, there is a certain condition that meets the total reflection condition coming from the stray light prevention means and the aperture structure Although only stray light with a range of angles can be reflected in a specific direction, the reflection range by the deposited film can be increased to widen the range of angles that can be reflected, thereby improving stray light prevention performance.

  Further, the image forming means of the optical pointing device according to the present invention may be configured by any one of a spherical surface, an aspherical surface, and a toroidal surface.

  Based on optical aberrations such as spherical aberration and coma generated from the optical system configuration of the optical pointing device, and the amount of distortion of the image projected on the image sensor, the curvature of the imaging means is spherical, aspherical, or toroidal. By appropriately setting the surface, the optical characteristics of the optical system of the optical pointing device can be further improved.

  Further, the image forming means of the optical pointing device according to the present invention may be provided with reflection performance by a vapor deposition film obtained by vapor deposition of metal, dielectric or the like.

  With the above configuration, it is possible to reduce the size of the optical pointing device in the planar direction, in which scattered light from the subject can be reflected by the imaging unit and returned to the subject direction.

  Further, the optical path deflecting means of the optical pointing device according to the present invention is constituted by any of a total reflection surface, a deposition film reflection surface on which a metal or a dielectric is deposited, a reflection diffraction grating surface or a reflection hologram surface. May be.

  When the optical path deflecting means is a total reflection surface, the light projected on the image sensor is the highest in light use efficiency with respect to a vapor deposition reflection surface, a reflection type diffraction grating surface and a reflection type hologram surface, which will be described later. Since it becomes brighter, the S / N ratio is improved. Further, when the optical path deflecting means is a vapor deposition reflecting surface, the light use efficiency is lowered, but the light incident on the optical path deflecting means can be reliably reflected.

  The surface of the cover where the contact surface is located may contact the subject. When the subject contacts a location other than the contact surface, the reflected light is reflected when the reflected light is reflected at the location where the subject is in contact. Is reflected on the surface of the object, not reflected on the surface of the cover, and thus the reflected light path is shifted. Therefore, by arranging the vapor deposition reflective film at this location, it is possible to suppress the occurrence of deviation of the path of the reflected light, the imaging performance of the imaging element is improved, and the imaging element captures the image of the subject. A clear image can be taken.

  Further, when the optical path deflecting means is a reflection type diffraction element and a reflection type hologram surface, the light use efficiency is lowered as in the case of the vapor deposition film reflection surface, but the optical path deflection is performed in the direction opposite to the contact surface of the cover part. When forming the means, the cover portion including the function of the optical path deflecting means can be formed without forming a concave portion therefor. Therefore, the thickness of the entire cover portion can be made uniform from the cover portion including the bending element of the concave portion, and the cover portion can be thinned while increasing the strength of the cover portion. In addition, when the deflecting means is a reflection hologram surface, it can also have a role of correcting aberrations that cannot be corrected by the imaging means, so that the imaging element that reflects the reflected light of the bending element can be used. The imaging performance is improved, and the image pickup device can pick up a subject image clearly.

  By appropriately using each of these reflecting surfaces, the performance of the optical pointing device can be improved.

  The optical pointing device according to the present invention may further include a light source covered with the cover member, and the scattered light from the subject may be generated based on light emitted from the light source.

  According to the above configuration, the scattered light is generated based on light emitted from the light source and reflected by the subject. Therefore, the angle at which the light emitted from the light source irradiates the subject can be aligned to some extent. Therefore, even when the illuminance of the light source is lowered, a sufficient amount of light for detecting the subject can be maintained. Therefore, since the amount of current supplied to the light source can be reduced, the amount of current consumed by the optical pointing device can be suppressed.

  The light pointing device according to the present invention may be provided with a light blocking performance for blocking light from outside the device in a region other than the contact surface of the cover member positioned on the object plane in the imaging unit.

  In the light coming from the outside of the optical pointing device according to the present invention, the light from other than the object surface on the cover contact surface that provides good characteristics in the imaging means becomes disturbance light for the optical pointing device.

  According to said structure, since the influence of the said disturbance light can be suppressed, the contrast of the image image | photographed with the said image pick-up element improves.

  In the optical pointing device according to the present invention, each of the transparent resins in which the light source and the imaging element are resin-sealed has a substantially rectangular parallelepiped shape, and one side surface of the transparent resin in which the light source is resin-sealed is One side surface of the other transparent resin disposed on the same plane as the one side surface of the substrate and resin-sealed with the imaging element is disposed on the same plane as the other side surface of the substrate, The cover portion is disposed on the upper side of the substrate with reference to the front surface, both side surfaces of the substrate, and one side surface of the transparent resin in which the light source and the imaging element in the same plane are sealed with resin. Also good.

  According to the above configuration, the upper surface of each of the transparent resins, both side surfaces of the substrate, and one side surface of the transparent resin that is disposed on the same plane as the light source and the imaging element. The cover portion is disposed on the upper side of the substrate with reference to. Therefore, the positional relationship among the contact surface, the light source, the imaging element, the bending element, and the imaging element can be arranged with high accuracy. Therefore, an optical pointing device with high subject detection accuracy can be realized.

  An electronic apparatus according to the present invention includes the above optical pointing device.

  According to the above configuration, the electronic apparatus includes the optical pointing device that can be easily reduced in thickness. When the optical pointing device is mounted, the thickness of the optical pointing device greatly affects the thickness of the electronic device. Therefore, even if the optical pointing device is provided, the electronic device can be thinned.

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

  The present invention relates to 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 PDA (Personal Digital Assistants) that is particularly required to be small and thin, and an electronic device including the same. Can be suitably used.

10 Subject 11 Contact surface 12 Diffraction element (optical path conversion unit, prism)
12 'Diffraction element (optical path changer, reflection type diffraction element)
13 Inclined surface 14 Imaging element (imaging reflection part)
15 Image sensor 16 Light source 17 Reflecting surface (optical path conversion unit)
18 Reflecting surface (light path conversion part)
19A Stray light prevention prism (stray light prevention part)
24 Cover (light guide type optical member)
28A / 28B Light shielding films 30, 30a, 30b, 107 Optical pointing device 100 Mobile phone (electronic equipment)

Claims (12)

A light source that irradiates light to a subject, a light guide type optical member that reflects light reflected from the subject and guides the inside, and an image sensor that receives light guided by the light guide type optical member An optical pointing device comprising:
The light guide type optical member has an imaging reflection part that guides the guided light to the image sensor,
Furthermore, a stray light prevention unit that changes the path of light that is emitted from the light source and enters the image sensor without passing through the imaging reflection unit is provided on the back surface of the light guide type optical member on which the light source and the image sensor are provided. An optical pointing device comprising:   The light guide type optical member integrally includes the imaging reflection unit, a contact surface with which the subject contacts, and an optical path conversion unit that converts the direction of reflected light from the subject and guides it to the imaging reflection unit. The optical pointing device according to claim 1, wherein the optical pointing device is formed.   The optical pointing device according to claim 1, wherein the stray light prevention unit is a prism that refracts the guided light. The optical pointing device according to claim 1, wherein the stray light prevention unit includes an uneven dimple structure that scatters the guided light. 3. The optical pointing device according to claim 1, wherein a light-shielding film that absorbs the guided light is formed on the stray light prevention unit.   The optical pointing device according to claim 2, wherein the stray light prevention unit is formed integrally with the contact surface, the imaging reflection unit, and the optical path conversion unit.   4. The optical pointing device according to claim 3, wherein a reflection film for reflecting the guided light is formed on the prism surface.   8. The imaging reflecting portion according to claim 1, wherein the imaging reflection part has a toroidal surface having a spherical surface, an aspherical surface, or a toroidal surface in which a curvature of a surface in a light guide direction and a curvature of a surface orthogonal to the light guide direction are different from each other. The optical pointing device according to claim 1.   The optical path conversion unit includes any of a prism that refracts reflected light from the subject, a reflective diffraction element that deflects reflected light from the subject, a reflective Fresnel lens, or a reflective hologram lens. The optical pointing device according to claim 2.   The said light guide type optical member is equipped with the light-shielding film which light-shields the light from the outside in surface areas other than the contact surface which the said object contacts, The any one of Claims 1-9 characterized by the above-mentioned. Optical pointing device. The imaging element is provided on a substrate and is resin-sealed with a transparent resin.
The optical pointing device according to claim 1, wherein the light guide type optical member is in contact with a surface and a side surface of the transparent resin.   An electronic apparatus comprising the optical pointing device according to claim 1.

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