JP4758511B1 - Optical pointing device and electronic apparatus equipped with the same - Google Patents

Abstract

An optical pointing device capable of reducing the influence of stray light on image data captured by an image sensor without providing a new shielding wall, and an electronic apparatus including the same.
An optical pointing device includes a light source that irradiates light on a contact surface of a subject and an imaging reflecting mirror that forms an image of scattered light from the subject on an image sensor. In the outer peripheral area of the imaging mirror 14 and within the range where the direct light from the light source 16, the scattered light from the subject 10, or other disturbance light reaches, the light reflected by the outer peripheral area or the outer peripheral area is transmitted. A structure S1 that suppresses light from entering the image sensor 15 as noise light is provided.
[Selection] Figure 1

Description

  The present invention relates to an optical pointing device that can be mounted on a portable information terminal such as a mobile phone as an electronic device, and an electronic device including the same, and more particularly, an optical pointing device that is less affected by stray light and the same. Related to electronic equipment.

  In a small electronic device typified by a portable information terminal such as a mobile phone or PDA (Personal Digital Assistants), 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 portable information terminals, 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 has high functionality and has a display function equivalent to that of a computer, the input means of the conventional portable information terminal that uses the menu key and other function keys as direction keys are expressed in GUI. It was inconvenient because it was not suitable for selecting icons. 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-type mouse or an optical mouse used in computers, 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, for example, 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, the fingerprint of a finger as a subject that contacts the pointing device is observed with an image sensor, and the movement of the subject's fingerprint on the contact surface is extracted to thereby detect the movement of the subject. An optical pointing device for detection has been proposed. That is, an image of a subject formed by light reflected by the subject is continuously captured by an imaging device 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 of change 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.

  As this type of optical pointing device, 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 device is placed horizontally), and a horizontal light beam. An optical joystick is disclosed that includes a condenser lens and an image sensor (imaging device) that are vertically disposed opposite to each other on a path. Thereby, it is possible to realize an optical pointing device having a short length in the vertical direction while taking a long optical path, thereby realizing a reduction in thickness of the optical pointing device.

JP 2009-176271 A (released on August 6, 2009)

  By the way, in an optical pointing device that emits light from a light source and bends reflected light from a subject in the horizontal direction to form an image on an image sensor, it is necessary to prevent stray light from the light source or the like from entering the image sensor. is there.

  In this regard, in the optical joystick 100 disclosed in Patent Document 1, as shown in FIG. 13, the light from the light source 105 is collected by the prism 101 and the collecting light in the optical member 104 constituting the prisms 101 and 102 and the condenser lens 103. When passing through the optical lens 103 and the prism 102, stray light that diffuses to the side is blocked by a block-shaped holder 107. Further, the stray light diffusing upward is shielded by the sheet-shaped sparse light shielding wall 111 provided on the upper side of the optical member 104, and the stray light diffusing downward is provided on the lower side of the optical member 104. It is shielded by the shielding wall 112.

  However, in the conventional optical pointing device, providing a shielding wall as disclosed in Patent Document 1 becomes an obstacle to further reducing the thickness and size. As a result, there is a problem that stray light cannot be prevented from entering the image sensor.

  When stray light is received by the image sensor, when the image sensor receives light reflected from the subject (scattered light), the light (scattered light) cannot be sufficiently recognized due to the influence of stray light, The performance of the optical pointing device is degraded. 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 that can reduce the influence of stray light on image data captured by an image sensor without providing a new shielding wall. And providing an electronic apparatus including the same.

  In order to solve the above problems, an optical pointing device of the present invention includes an optical pointing device including a light source that irradiates light on a contact surface of a subject and an imaging element that forms an image of scattered light from the subject on an imaging device. In the apparatus, the light reflected by the outer peripheral region or transmitted through the outer peripheral region is within the outer peripheral region of the imaging element, and the range where direct light from the light source, scattered light from the subject, or other disturbance light reaches. It is characterized in that a structure that suppresses the incident light as noise light to the image pickup device by changing the optical path of the light is provided.

  According to the above invention, the optical pointing device includes the light source that irradiates light on the contact surface of the subject, and the imaging element that forms an image of the scattered light from the subject on the imaging element. Therefore, by adopting such an optical pointing device, the optical path length of the optical system can be made longer, the length in the vertical direction can be made smaller than the optical path length, and miniaturization can be achieved.

  However, in such an optical pointing device, direct light from the light source, scattered light from the subject, or other disturbance light may be directly incident on the image sensor without passing through the imaging element. Etc. reduce the S / N (Signal / Noise) of the image sensor.

  On the other hand, in the present invention, in the outer peripheral region of the imaging element and within the range where direct light from the light source, scattered light from the subject, or other disturbance light reaches, the light reflected by the outer peripheral region or There is provided a structure that changes the optical path of the light transmitted through the outer peripheral region and prevents the light from entering the imaging element as noise light. This structure is made of a scattering surface such as a prism.

  For this reason, light or the like from the light source that is not reflected by the subject that causes stray light or the like is reflected by the structure in a specific direction and is prevented from entering the imaging element as noise light. As a result, it is possible to prevent the light emitted from the light source from becoming stray light without being reflected by the subject.

  Further, the structure is not a new shielding wall because it suppresses incident light as noise light by changing the optical path of the light reflected by the outer peripheral region or the light transmitted through the outer peripheral region.

  Therefore, 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 without providing a new shielding wall.

  In the optical pointing device of the present invention, it is preferable that the contact surface, the imaging element, and the structure are integrally provided on a light guide member that propagates scattered light from a subject.

  Thereby, since the structure is integrally formed with the optical system of the optical member such as the contact surface and the imaging element, the optical member and the structure can be assembled with high accuracy and the number of parts can be reduced. be able to.

  In the optical pointing device of the present invention, it is preferable that the structures are provided on both sides in the vertical direction or both sides in the horizontal direction of the imaging element.

  As a result, the structure can be formed at the same time as the imaging element is formed, so that the manufacturing efficiency of the structure is improved.

  In the optical pointing device of the present invention, it is preferable that the light guide member also serves as a cover member.

  As a result, it is possible to assemble the light guide member with higher accuracy than when the cover member and the light guide member are attached by separate members, and the number of components can be reduced.

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

  According to the above invention, it is possible to provide an electronic apparatus including an optical pointing device in which the influence of stray light on image data captured by an image sensor is reduced.

  As described above, the optical pointing device of the present invention is an outer peripheral region of the imaging element, and is within the outer region in a range where direct light from the light source, scattered light from the subject, or other disturbance light reaches. A structure that suppresses the incident light as noise light by changing the optical path of the reflected light or the light transmitted through the outer peripheral region is provided.

  In addition, as described above, an electronic apparatus according to the present invention includes the above-described optical pointing device.

  Therefore, it is possible to provide an optical pointing device that can reduce the influence of stray light on image data captured by the image sensor without providing a new shielding wall, and an electronic device including the same.

(A) shows one Embodiment of the optical pointing device in this invention, Comprising: It is sectional drawing which shows the structure of an optical pointing device, (b) is a perspective view which shows the structure of the cover part of the said optical pointing device. FIG. It is a bottom view which shows the optical path from a light source when a structure does not exist in the outer periphery of the image formation element in the said optical pointing device. It is a bottom view which shows the optical path from a light source in case the structure exists in the outer periphery of the image formation element in the said optical pointing device. (A) is a top view which shows the structure of the other structure in an optical pointing device, (b) is the sectional view on the A-A 'line of (a). (A) is a top view which shows the structure of the other structure in an optical pointing device, (b) is the B-B 'sectional view taken on the line of (a). (A) is a top view which shows the structure of the other structure in an optical pointing device, (b) is the C-C 'sectional view taken on the line of (a). It is a bottom view which shows the optical path from a light source in case the structure does not exist in the side surface side flange of the cover part in the said optical pointing device. It is a bottom view which shows the optical path from a light source in case the structure exists in the side surface side flange of the cover part in the said optical pointing device. It is a bottom view which shows the optical path from a light source in case the structure exists in the front-and-rear side flange of the cover part in the said optical pointing device. FIG. 5 is a cross-sectional view showing another embodiment of the optical pointing device according to the present invention, showing the configuration of the optical pointing device including a lens and the optical path from the light source. It is a top view which shows the structure of the optical pointing device provided with the said lens, and the optical path from a light source. (A) shows one Embodiment of the electronic device provided with the optical pointing device in this invention, Comprising: It is a front view which shows the external appearance of the mobile telephone as an electronic device carrying an optical pointing device, (b) ) Is a rear view thereof, and (c) is a side view thereof. It is an assembly exploded perspective view which shows the structure of the conventional optical pointing device.

  Each 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 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. In addition, about the member which shows the same function and effect | action, the same code | symbol is attached | subjected and description is abbreviate | omitted.

[Embodiment 1]
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1A is a schematic cross-sectional view showing an optical pointing device 30 according to the first embodiment, and FIG. 1B is a perspective view showing a configuration of a cover portion of the optical pointing device.

  As shown in FIG. 1A, the optical pointing device 30 of the present embodiment includes a substrate portion 26 and a cover portion 24 that is a light guide type optical member. The board portion 26 includes a circuit board 21, a light source 16, an image sensor 15, and a transparent resin 20. The cover portion 24 includes a contact surface 11, an optical path changing unit that forms the inclined surface 13, a bending element 12 as a prism, an imaging reflecting mirror 14 as an imaging element, and reflecting surfaces 17 and 18. 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 of the optical pointing device 30 (vertical direction in FIG. 1A) is taken as the Z axis, and the width direction of the optical pointing device 30 (lateral direction in FIG. 1A) 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 configuration of the substrate part 26 will be described.

  In the substrate unit 26 of the present embodiment, the light source 16 and the imaging element 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 electric signal output from the image sensor 15 to detect the movement of the subject 10. 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 irradiation light M irradiated from the light source 16 is refracted by the bending element 12 of the cover portion 24 through the transparent resin 20 and the traveling direction is changed to reach the contact surface 11. That is, the irradiation light M is incident on the contact surface 11 from an oblique direction, that is, 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, a part of the irradiation light M that has reached the contact surface 11 when the subject 10 is not on the contact surface 11 is a contact surface. 11, and the remaining part is reflected by the contact surface 11. At this time, when the incident angle of the irradiation light M with respect to the contact surface 11 satisfies the condition of total reflection, the irradiation 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 irradiation 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 (Light Emitting Diode), and is preferably realized by an infrared light emitting diode with high luminance.

  The image sensor 15 receives the scattered reflected light L reflected by 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 pickup device 15 is composed of an image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device). The image sensor 15 includes a DSP (Digital Signal Processor: calculation unit) (not shown), and takes the received irradiation light M 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. 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 sealed with a transparent resin 20 which is 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 constituting the transparent resin 20, 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 detection accuracy of the subject 10 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. That is, some of the contact surfaces 24 a and 24 b on the back surface of the cover portion 24 are in close contact with the side surface and the upper surface of the substrate portion 26. In the present embodiment, the surface portion of the cover portion 24 on the negative side of the Z-axis that is not exposed to the outside when mounted on the substrate portion 26 and formed as the optical pointing device 30 is used. This is referred to as the back surface of the cover portion 24.

  Further, the bottom surface 24 c of the cover part 24 forms the same plane as the bottom surface 26 a of the substrate part 26. Furthermore, the upper surface of the cover part 24, the contact surface 24b of the cover part 24, the bottom surface 26a of the substrate part 26 and the bottom surface 24c of the cover part 24 are parallel to each other, and both side surfaces of the cover part 24 are covered. The upper surface of the portion 24, the contact surface 24 b of the cover portion 24, and the surface having a certain angle with respect to the bottom surface 26 a of the substrate portion 26 and the bottom surface 24 c of the cover portion 24 are formed. That is, as shown in FIG. 1, in the cross-sectional view of the optical pointing device 30, the cover portion 24 has a trapezoidal shape. However, the cover portion 24 is not limited to this shape, and the side surface may be perpendicular to the bottom surface 24c.

  Front and rear flanges 25 and side flanges 27 are provided in the vicinity of the front and rear and side bottoms of the cover 24. The front and rear flanges 25 and the side flanges 27 are mounted on the electronic device by the optical pointing device 30 of the present embodiment, and are pushed from the contact surface 11 of the cover portion 24 by the subject 10 such as a finger in the negative direction of the Z axis. In this case, the force generated in the positive direction of the Z-axis by a leaf spring contact switch (not shown) provided on the bottom surface 26a of the substrate portion 26 is regulated at a certain position, and a certain stroke amount required as a pushbutton switch Used to ensure.

  The contact surface 11 in the cover unit 24 is a surface on which the subject 10 is in contact with the optical pointing device 30. The contact surface 11 is located above the light source 16 on the upper surface of the cover portion 24.

  The bending element 12 is formed of a prism, and is located above the light source 16 and below the contact surface 11, and is located on a portion of the back surface of the cover portion 24 that is not in contact with the substrate portion 26. Are formed. 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 irradiation light M irradiated from the light source 16 on the inclined surface 13 and converts the path of the irradiation light M so as to go to the subject 10. Further, the bending element 12 totally reflects the scattered reflected light L reflected from the subject 10 by the inclined surface 13 and converts the path of the scattered reflected light L in the positive direction of the Y axis inside the cover portion 24. is there. The scattered reflected light L reflected from the subject 10 that has been totally reflected by the inclined surface 13 is directed to the reflecting surface 17 described later. Thus, the inclined surface 13 of the bending element 12 transmits the irradiation light M and totally reflects the scattered reflected light L. Therefore, a material having a refractive index larger than the refractive index of the space between the cover portion 24 and the substrate portion 26 above the light source 16 is used for the cover portion 24. For example, the cover portion 24 may be made of a visible light absorption type polycarbonate resin or acrylic resin having a refractive index of about 1.5, and the space may be an air layer. 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 scattered reflected light L.

  Further, a stray light countermeasure notch 19 is formed in the positive direction of the Y axis from the end of the total reflection surface of the bending element 12 on the contact surface 24b side of the cover portion 24.

  The imaging reflecting mirror 14 reflects the scattered reflected light L from the subject 10 and forms an image of the subject 10 on the image sensor 15. The imaging reflecting mirror 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 a portion of the back surface of the cover 24 that is not in contact with the substrate unit 26. A recess is formed on the back surface. For example, a toroidal surface having different curvatures in two orthogonal directions is formed on the imaging mirror 14. The imaging reflecting mirror 14 reflects the scattered reflected light L so as to form an image on the image sensor 15 by the toroidal surface. In order to efficiently reflect the scattered reflected light L at the imaging reflecting mirror 14, a reflective film made of a metal such as aluminum, nickel, gold, silver, or a dielectric dichroic film is formed on the toroidal surface of the imaging reflecting mirror 14. Is vapor-deposited.

  In the above description, the imaging reflector 14 is formed with, for example, a toroidal surface. However, the present invention is not limited to this. For example, the imaging reflector 14 is a reflector such as a spherical surface or an aspherical surface. Any material that can form an image can be used.

  The reflecting surface 17 causes the scattered reflected light L totally reflected by the inclined surface 13 to enter the imaging reflecting mirror 14 and causes the scattered reflected light L reflected from the imaging reflecting mirror 14 to enter the imaging device 15. The scattered reflected light L is reflected. 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 red in the wavelength band of 800 nm or more emitted from the light source 16. Any device that reflects external light and transmits light having a visible wavelength band of 800 nm or less may be used. As described above, by appropriately setting the wavelength of the light emitted from the light source 16 and the characteristics of the reflectance and transmittance of the reflecting film forming the reflecting surface 17, the scattered reflected light L from the subject 10 is efficiently reflected. In addition, it is possible to form the reflecting surface 17 that 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 material of the cover portion 24 is a visible light absorption type polycarbonate resin or acrylic resin that transmits only infrared light. You can do it. 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.

  Further, when coloring the surface of the cover unit 24, which is the surface of the optical pointing device 30, for example, only the wavelength band of a predetermined color such as green is formed on the upper surface of the cover unit 24 and the upper surface of the reflection surface 17, for example. May be coated with a material having a characteristic of reflecting other wavelengths and transmitting other wavelengths. By coating the upper surface of the cover portion 24 and the upper surface of the reflection 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 scattered reflected light L reflected from the imaging reflecting mirror 14 and reflected by the reflecting surface 17 toward the reflecting surface 17 again. The reflective 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 depositing a metal such as aluminum, nickel, gold, silver, or a dielectric dichroic film.

  As described above, in the optical pointing device 30 according to 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. The cover portion 24 has contact surfaces 24a and 24b serving 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 reflector 14, and the front and rear flanges 25 and the side flange 27 are formed integrally. Therefore, the contact surfaces 24a and 24b, the contact surfaces 11, the bending element 12, the imaging reflecting mirror 14, the front and rear side flanges 25, and the side surface side flanges 27 are arranged with high precision with mold tolerances. Therefore, by bringing the contact surfaces 24a and 24b of the cover portion 24 into contact with the side surfaces and the upper surface of the transparent resin 20 of the substrate portion 26, the positional relationship with the cover portion 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.

  In the optical pointing device 30 configured as described above, a path in which light emitted from the light source 16 is reflected by the subject 10 and enters the image sensor 15 will be described with reference to FIG.

  As shown in FIG. 1A, first, the irradiation light M irradiated 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 irradiation 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 scattered reflected 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 is changed in the positive direction of the Y axis. The scattered reflected light L totally reflected by the inclined surface 13 is reflected by the reflecting surface 17 and reaches the imaging reflecting mirror 14. Then, the scattered reflected light L is reflected back by the imaging reflecting mirror 14, is successively reflected by the reflecting surface 17, the reflecting surface 18, and the reflecting surface 17 and finally enters the image sensor 15.

  Thereby, signal information relating to the amount and direction of movement of the subject 10 when the subject 10 moves is obtained from the signal component obtained by image processing of the image picked up on the image sensor 15 by the scattered reflected light L on the circuit board 21. .

  By the way, in the optical pointing device 30 configured as described above, since the bending element 12 and the imaging reflecting mirror 14 are integrated in the cover portion 24 and the light source 16 and the imaging element 15 are close to each other, the reflected light from the subject 10 is reflected. Alternatively, direct light from the light source 16 may be directly incident on the image sensor 15 without passing through the imaging mirror 14.

  As a result, as shown in FIG. 2, for example, a similar image by direct light from the light source 16 passing through the optical path M1 can be obtained only when the subject 10 moves, so that only the image that does not move is obtained. Not only cannot be obtained, but the non-moving image overlaps the moving image, hiding the movement of the image, so that accurate signal information cannot be obtained. Here, in the following description, light passing through the optical path of the scattered reflected light L from which signal information is obtained is referred to as signal light, and light other than the signal light is referred to as noise light. Further, noise light generated by the light source 16 inside the optical pointing device 30 is defined as stray light, and noise light generated by light incident from the outside of the optical pointing device is defined as disturbance light. The stray light is imaged reflection of the direct light that directly enters the image sensor 15 without passing through the subject 10 and the imaging reflector 14 from the light source 16 and the scattered light from the subject 10 based on the light from the light source 16. Light directly incident on the image sensor 15 without passing through the mirror 14.

  That is, the S / N ratio of the image sensor 15 is expressed by Signal (signal light) / Noise (noise light), and noise light that lowers the S / N ratio needs to be removed.

  Therefore, in the present embodiment, in order to solve this problem, in the outer peripheral region of the imaging reflecting mirror 14 and within the range where direct light from the light source 16, scattered light from the subject 10, or other disturbance light reaches. A structure S1 is provided that suppresses incident light as noise light by changing the optical path of light reflected by the outer peripheral region or transmitted through the outer peripheral region.

  Specifically, for example, as shown in FIG. 1B, the structures S <b> 1 are provided on both sides of the imaging reflecting mirror 14 in the same plane as the imaging reflecting mirror 14. FIG. 1B is a perspective view of the cover portion 24 of FIG. 1A as viewed from the Z-axis direction negative toward the positive direction.

  In the optical pointing device 30 provided with the structure S1, as shown in FIG. 3, the stray light M1 is changed into a stray light M1 'and changed to a light beam in a direction different from that of the image sensor 15, so that it does not become stray light. In addition, even when the light is transmitted and refracted, the stray light M1 is changed to a stray light M1 ″ and changed to a light beam in a direction different from that of the image sensor 15, so that it does not become stray light.

  Here, the structure S1 is preferably formed of a scattering surface. By using a scattering surface as the structure S1, light from the light source 16 that does not pass through the subject 10 that causes stray light is scattered on the scattering surface. Accordingly, it is possible to reliably prevent the light emitted from the light source 16 from becoming stray light without being reflected by the subject 10.

  More specifically, the structure S1 is preferably made of a prism. Since this prism reflects incident light, it reflects stray light. Therefore, stray light can be reliably prevented from entering the imaging surface. Further, since the prism transmits and refracts the stray light, the stray light can be reliably prevented from entering the imaging surface.

  In the structure S1 including the prism, the amount of stray light incident on the imaging surface when the apex angle of the prism is 90 °, the pitch is 44 μm, and the depth is 23 μm was examined. As a result, when the total amount of light incident on the imaging surface is 100%, the stray light amount is 0.022% when the structure S1 is not provided, whereas when the structure S1 is provided. The stray light amount was 0.002%, and the stray light amount was reduced to 1/10.

  Here, as a concrete shape of the structure S1 made of a prism, for example, those shown in FIGS. 4 to 6 can be considered.

For example, as shown in FIG. 4 (a) (b), it may be a structure S1 ₁ in which the prism cross-sectional shape as a right triangle. This structure structure S1 ₁ is easy to machining, and the optical pointing device 30 contact surface 11 and the image forming reflecting mirror 14 is formed integrally with the cover portion 24, simultaneously with the image forming reflecting mirror 14 Since it can be cut, there is an advantage that the production efficiency is improved.

Further, as shown in FIG. 5 (a) (b), a circular cross section prism cross sectional shape, that is, a prism shape may be a structure S1 ₂ having an uneven sphere. This structure structure S1 _2, since the scattering effect can be expected as compared with the structure S1 _1, it is possible to prevent the stray light is incident on the imaging surface, it is possible to further reduce the strength of the stray light.

Furthermore, as shown in FIG. 6 (a) (b), it may be a structure S1 ₃ having an uneven surface of the square estimated prism shape. In this structure the structure S1 _3, is easily machined, and the contact surface 11 and the image forming reflecting mirror 14 in the optical pointing device 30 is formed integrally with the cover portion 24, an image forming reflecting mirror 14 Since it can be cut at the same time, the production efficiency is improved. Further, since the prism shapes are provided on both sides compared to the one-side prism shape, there is an advantage that stray light can be efficiently prevented.

  On the other hand, as another example of the range where the direct light from the light source 16 and the scattered light from the subject 10 reach in the outer peripheral area of the imaging mirror 14, for example, the one shown in FIG. FIG. 7 is a view showing the stray light M2 and the stray light M3 passing through the front and rear flanges 25 and the side flanges 27 in the cover portion 24. FIG.

  In the present embodiment, in order to cope with this stray light M3, as shown in FIG. 8, a structure S2 is provided on the side flange 27. Similarly to the structure S1, the structure S2 can also be a structure S2 made of a prism. As a result, the stray light M3 passing through the side flange 27 is changed to a stray light M3 ', and the stray light M3 is changed to a light beam in a direction different from that of the image sensor 15, so that it does not become stray light. Also, when the structure S2 is provided to transmit and refract the light, the stray light M3 is changed to a stray light M3 ″ and changed to a light beam having a direction different from that of the image sensor 15, so that it does not become stray light.

  Further, in order to cope with the stray light M2, it is possible to provide a structure S3 on the front and rear flange 25 as shown in FIG. Similarly to the structure S1, the structure S3 can also be a structure S3 made of a prism. As a result, the stray light M2 passing through the front and rear flanges 25 is changed to a stray light M2 ', and the light path is changed to a light beam in a direction different from that of the image sensor 15, so that it does not become stray light. Further, when the structure S3 is provided to transmit and refract the light, the stray light M2 is changed to a stray light M2 ″ and changed to a light beam having a direction different from that of the imaging element 15, so that the stray light is not generated.

  As described above, the optical pointing device 30 according to the present embodiment includes the light source 16 that irradiates light on the contact surface 11 of the subject 10 and the imaging reflector 14 that forms an image of the scattered light from the subject 10 on the image sensor 15. And. Therefore, by adopting such an optical pointing device 30, the optical path length of the optical system can be made longer, the length in the vertical direction can be made smaller than the optical path length, and miniaturization can be achieved.

  However, in such an optical pointing device 30, direct light from the light source 16, scattered reflected light L from the subject 10, or other disturbance light directly enters the image sensor 15 without passing through the imaging reflector 14. In some cases, such stray light or the like reduces the S / N (Signal / Noise) of the image sensor.

  On the other hand, in the present embodiment, in the outer peripheral area of the imaging reflecting mirror 14 and within the range where the direct light from the light source 16, the scattered light from the subject 10, or other disturbance light reaches, The structure S <b> 1 is provided that suppresses the incident light as noise light by changing the optical path of the reflected light or the light transmitted through the outer peripheral region. And structure S1 consists of scattering surfaces, such as a prism, for example.

  For this reason, the light from the light source 16 that is not reflected by the subject 10 that causes stray light or the like is reflected by the structure S1 in a specific direction and is prevented from entering the imaging element 15 as noise light. . As a result, the light emitted from the light source 16 can be prevented from becoming stray light without being reflected by the subject 10.

  Further, the structure S1 is not a new shielding wall because the structure S1 suppresses incident light as noise light to the imaging element 15 by changing the optical path of light reflected by the outer peripheral region or transmitted through the outer peripheral region. .

  Therefore, 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 without providing a new shielding wall.

  Further, in the optical pointing device 30 according to the present embodiment, the contact surface 11, the imaging reflector 14, and the structure S <b> 1 are integrally provided on the cover unit 24 that is a light guide member that propagates scattered light from the subject 10. ing.

  Thereby, since the structure S1 is integrally formed with the optical system of the optical member such as the contact surface 11 and the imaging reflecting mirror 14, the optical member and the structure S1 can be assembled with high accuracy. The number of parts can be reduced.

  Further, in the subject 10 of the present embodiment, the structures S1 are provided on both sides of the imaging reflecting mirror 14 in the lateral direction. Thereby, since the structure S1 can be formed at the same time when the imaging mirror 14 is formed, the manufacturing efficiency of the structure S1 is improved.

  Further, in the optical pointing device 30 of the present embodiment, the cover portion 24 as a light guide member also serves as a cover member. As a result, it is possible to assemble the light guide member with higher accuracy than when the cover member and the light guide member are attached by separate members, and the number of components can be reduced.

[Embodiment 2]
A second embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a schematic sectional view showing the optical pointing device 40 of the second embodiment. As shown in FIG. 10, in the present embodiment, a lens 42 as an imaging element is used in place of the imaging reflecting mirror 14 composed of the reflecting mirror as the imaging element in the first embodiment. Is different.

  In the optical pointing device 40 of the present embodiment, as shown in FIG. 10, the image of the subject 10 such as a fingertip is captured as scattered reflected light L from the contact surface 11 that is the upper surface in the vertical direction of the bending element 12. It is. The scattered reflected light L reflects the inclined surface 43 of the bending element 12, forms an image by a lens 42 as an imaging element, reflects the inclined surface 44, and is taken in as image data by the imaging element 15. Changes in the contact surface 11 are extracted from the image data obtained from the image sensor 15 by image processing, and the amount and direction of movement of the subject 10 can be obtained.

  In this case, since the scattered reflected light L has a role of transmitting the change of the contact surface 11 to the imaging element 15, the scattered reflected light L is signal light. A light source 16 constituting a light source module for illuminating the subject 10 is disposed under the bending element 12. Therefore, in the present embodiment, stray light M4 is given as stray light for the signal light of the scattered reflected light L, as shown in FIG.

  Therefore, in the present embodiment, in order to prevent the stray light M4 from entering the image sensor 15, the structures S4 are provided vertically above and below the same plane as the lens 42. By providing this structure S4, as shown in FIG. 10, the stray light M4 is reflected in a direction different from that of the image pickup device 15 and changes to the stray light M4 ′. Therefore, the stray light M4 does not enter the image pickup device 15. . Further, even when the structure S4 is provided in order to transmit and refract the light, the stray light M4 is changed to a stray light M4 ″ and changed to a light beam in a direction different from that of the image sensor 15, so that it does not become stray light.

  Further, in the present embodiment, the structure S4 and the lens 42 are on the same plane. Therefore, in order to reduce stray light, for example, when using an aperture as a well-known member, it is necessary to assemble the lens 42 and the aperture as separate members when using the aperture. On the other hand, in the present embodiment, the structure S4 is integrated with the lens 42, so that the alignment is easy. For this reason, it can assemble with high precision compared with the case where an aperture is used.

  In the above description, the structures S4 are provided vertically above and below the same plane as the lens 42. However, the structure S4 is not necessarily limited to this, and for example, as shown in FIG. It is possible to make the structures S5 provided on both sides in the lateral direction.

  Thereby, the stray light M5 from the light source 16 is changed in the optical path to the stray light M5 'and does not enter the image sensor 15, so that the performance of the optical pointing device 40 can be prevented from being deteriorated. Further, when the structure S5 is provided to transmit and refract the light, the stray light M5 is changed into a light beam in a direction different from that of the image sensor 15 because the optical path is changed to the stray light M5 '', so that it does not become stray light.

  Thus, in the optical pointing device 40 of the present embodiment, the structures S4 and S5 are provided on both sides in the vertical direction or both sides in the horizontal direction of the lens 42 as the imaging element.

  Thereby, since the structures S4 and S5 can be formed at the same time when the lens 42 as the imaging element is formed, the manufacturing efficiency of the structures S4 and S5 is improved.

[Embodiment 3]
Finally, an electronic device in which the optical pointing device 30 or 40 according to this embodiment is mounted will be described with reference to FIGS. 12 (a), 12 (b), and 12 (c). FIGS. 12A, 12B, and 12C are views showing the appearance of a cellular phone 60 as an electronic device on which any one of the optical pointing devices 30 and 40 is mounted. 12A is a front view of the mobile phone 60, FIG. 12B is a rear view of the mobile phone 60, and FIG. 12C is a side view of the mobile phone 60. 12A, 12B, and 12C show an example in which the mobile phone 60 is used as the electronic device, the present invention is not limited to this. The electronic device may be, for example, a PC (particularly a mobile PC), a PDA (Personal Digital Assistant: personal digital assistant), a game machine, a remote controller such as a television, or the like.

  As shown in FIGS. 12A, 12 </ b> B, and 12 </ b> C, the cellular phone 60 includes a monitor-side casing 61 and an operation-side casing 62. The monitor-side casing 61 includes a monitor unit 65 and a speaker unit 66, and the operation-side casing 62 includes a microphone unit 63, a numeric keypad 64, and the optical pointing device 30, for example. The optical pointing device 30 mounted on the mobile phone 60 is not necessarily limited to this, and can also be applied to the optical pointing device 40.

  In this embodiment, as shown in FIG. 12A, the optical pointing device 30 is arranged on the upper part of the numeric keypad 64. However, the arrangement method and the direction of the optical pointing device 30 are limited to this. It is not done.

  The speaker unit 66 outputs audio information to the outside, and the microphone unit 63 inputs audio information to the mobile phone 60. The monitor unit 65 outputs video information. In the present embodiment, the monitor unit 65 displays input information from the optical pointing device 30.

  Note that, as shown in FIGS. 12A, 12B, and 12C, the cellular phone 60 of the present embodiment includes an upper casing (monitor side casing 61) and a lower casing (operation side casing 62). And a so-called foldable mobile phone 60 that is connected via a hinge. Since the folding type is the mainstream of the cellular phone 60, a folding cellular phone is given as an example in the present embodiment, and the cellular phone 60 on which the optical pointing device 30 can be mounted is a folding type. It is not limited to.

  In recent years, a folding mobile phone 60 having a thickness of 10 mm or less in a folded state has appeared. If the portability of the mobile phone 60 is taken into consideration, its thickness is an extremely important factor. In the operation side casing 62 shown in FIGS. 12A, 12B, and 12C, components that determine the thickness of the operation side casing 62 excluding an internal circuit board (not shown) are the microphone unit 63, the numeric keypad 64, and the optical pointing device 30. It is. Among these, the thickness of the optical pointing device 30 is the largest, and the thinning of the optical pointing device 30 directly leads to the thinning of the mobile phone 60. Therefore, the optical pointing device of the present invention that can be reduced in thickness as described above is a preferred invention for electronic devices that require a reduction in thickness, such as the cellular phone 60.

  As described above, the cellular phone 60 as the electronic apparatus according to the present embodiment includes the optical pointing devices 30 and 40. Therefore, when using the cover unit 24 in which the light guide member and the imaging reflecting mirror 14 or the lens 42 are integrated, the optical pointing devices 30 and 40 that are less affected by stray light on the image data captured by the image sensor 15 are provided. The mobile phone 60 provided can be provided.

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

  The present invention can be used for an input device such as a PC or a mobile phone, and can be suitably used for a portable device that is particularly required to be small and thin.

10 Subject 11 Contact surface 12 Bending element 13 Slope 14 Imaging mirror (imaging element)
DESCRIPTION OF SYMBOLS 15 Image pick-up element 16 Light source 17 * 18 Reflective surface 19 Notch part 20 Transparent resin 21 Circuit board 24 Cover part 24a Contact surface 24b of Y direction Contact surface 24c of Z direction Bottom face 25 Front and rear side flange 26 Substrate part 26a Bottom face 27 Side surface Side flange 30 Optical pointing device 40 Optical pointing device 42 Lens (imaging element)
43 Inclined surface 44 Inclined surface 60 Mobile phone L Scattered reflected light M Light irradiated from light source M1 to M5 Stray light from light source S1 to S5 Structure S1 _{1 to} S1 ₃ Structure θ Inclination angle

Claims (5)

In an optical pointing device comprising: a light source that irradiates light on a contact surface of a subject; and an imaging element that forms an image of scattered light from the subject on an imaging device;
In the outer peripheral area of the imaging element and within the reach of direct light from the light source, scattered light from the subject or other disturbance light, the light reflected by the outer peripheral area or transmitted through the outer peripheral area An optical pointing device, characterized in that a structure that suppresses incident light as noise light to the image pickup device by changing an optical path is provided.   The optical pointing device according to claim 1, wherein the contact surface, the imaging element, and the structure are integrally provided on a light guide member that propagates scattered light from a subject. The imaging element and the structure are provided separately from a light guide member that propagates scattered light from a subject,
Wherein the structure, the optical pointing device according to claim 1, characterized in that provided on both sides of the longitudinal sides or lateral imaging element.   3. The optical pointing device according to claim 2, wherein the light guide member also serves as a cover member.   An electronic apparatus comprising the optical pointing device according to claim 1.

Images