JP5122494B2 - Optical pointing device and electronic apparatus equipped with the device - Google Patents

Description

  The present invention relates to an input device, and more particularly to an optical pointing device that can be mounted on an electronic device such as a mobile phone.

  Electronic devices such as mobile phones and PDAs (Personal Digital Assistants) employ a user interface that uses a keypad, which has a plurality of buttons for inputting numbers and characters, a direction It consists of buttons. On the other hand, in recent years, with the improvement in performance of displays, the adoption of GUI (Graphical User Interface) has become mainstream in electronic devices.

  In this way, the function of an electronic device such as a portable information terminal changes in a manner similar to that of a computer, so that the input method also performs a desired function by using conventional menu keys and other function keys as direction keys. This method is inconvenient, and a pointing device that enables operations such as a mouse and a touch pad used in a computer has been demanded.

  As the pointing device, there has been proposed an optical pointing device that extracts a change in a contact surface by observing a pattern of a subject such as a fingertip that contacts the device with an imaging device (Patent Document 1). In this configuration, the contact surface is illuminated by the light source, the pattern on the contact surface is imaged on the image sensor by the lens, and the movement of the fingertip is converted into an input signal from the detected change in the pattern.

  However, in the imaging optical system described above, a distance from the contact surface to the image sensor is required to form light from the contact surface on the image sensor, and the vertical length of the optical pointing device cannot be shortened. It was. Since electronic devices, particularly portable information terminals, are required to be thin, the optical pointing device is also required to reduce the vertical length.

  In order to satisfy the above requirements, a method of shortening the vertical length of the optical pointing device while keeping the optical path long by arranging a bending element such as a prism that bends the optical path directly under the contact surface and bending the optical path in the horizontal direction. Has been proposed (Patent Document 2). In this technique, since the optical path is bent in the horizontal direction, even if the optical path becomes long, the vertical length of the apparatus is not affected. For this reason, an optical pointing device having a short vertical length while realizing a long optical path is realized.

  On the other hand, in recent years, in particular, portable information terminals among electronic devices are required to be further thinned and downsized, and optical pointing devices are also required to be thin in the vertical direction and downsized in the horizontal direction. Yes. In the above-mentioned Patent Document 2, the optical path length has been increased in order to give priority to assembly, and there has been a problem that the downsizing of the optical pointing device in the horizontal direction is insufficient.

Special table 2007-528554 Special table 2008-510248

  The present invention has been made in view of the above-described problems, and provides an optical pointing device using a bending element, which is easy to assemble while being downsized in both the horizontal and vertical directions.

In order to solve the above-described problem, an optical pointing device according to an embodiment of the present invention includes:
A contact surface that a subject such as a fingertip touches;
A first bending element such as a prism having a first inclined surface for bending a light beam scattered and reflected by the subject by illumination light from external light or a light source provided separately;
An imaging element such as a lens for imaging the bent light beam as an image;
A second bending element such as a prism having a second inclined surface that bends the imaging light beam from the imaging element by reflection, preferably total reflection;
Having an imaging element such as a CCD for imaging the imaging light beam;
An angle between the first inclined surface and the contact surface is in a range of 40 ° to 45 °.

An optical pointing device according to an embodiment of the present invention includes:
The center point through which the optical axis of the imaging element passes is
It is characterized in that it is at a higher position that means the subject side as viewed from the thickness direction of the optical pointing device than the center of the first inclined surface through which the principal ray emitted from the center of the subject passes.

  With the above configuration, in the optical pointing device of the present invention, the first inclined surface is inclined in a direction in which the optical pointing device is thinned when viewed in the thickness direction of the optical pointing device.

  In addition, with the above-described configuration, an imaging element such as a lens can be viewed in the thickness direction of the optical pointing device, and the optical pointing device can be arranged in a thinning direction.

An optical pointing device according to an embodiment of the present invention includes:
An air conversion distance L between the contact surface and the imaging element is in a range defined by the following formula (1), and an imaging magnification M of the subject is set to 1 or less.

γ × (a / 2) × (COSφ + γ × SINφ) <L <a × Fe / (M × COSφ) (1)
(Where α is the angle of inclination between the first inclined surface and the contact surface, n is the refractive index of the first bending element, a is the photographing range of the subject on the contact surface, Φ is 2 × (45 ° −α), and Fe is the bond. The effective F number of the image element, M is the imaging magnification of the optical pointing device, and γ is TAN (90 ° −α + SIN ⁻¹ (1 / n)).
In the optical pointing device of the present invention, the optical path length of the imaging optical system can be shortened while changing the optical path in the horizontal direction by totally reflecting the scattered reflected light from the contact surface on the first inclined surface. I can do it. Therefore, the optical pointing device can be downsized not only in the vertical direction but also in the horizontal direction.

  When the optical path length is shortened, by making the air conversion distance L within the range of the above formula (1), a large amount of total reflection components can be secured, so the signal light amount with respect to noise light is high, that is, the SN ratio is high. It is possible to obtain a high recognition rate while being small.

An optical pointing device according to an embodiment of the present invention includes:
The second bending element is assembled by passive alignment that allows position adjustment to be realized only by fitting members together in the height direction and the optical axis direction with respect to the first bending element.

  With this configuration, even when the image-side distance of the image sensor is short, it is possible to prevent a focus shift or the like during assembly, and an optical pointing device that can be easily assembled while being small and thin.

  An electronic apparatus according to an embodiment includes the optical pointing device.

  According to the portable information terminal of this embodiment, since the optical pointing device is thin, the thickness of the electronic device can be reduced.

  According to the optical pointing device of the present invention, the inclined surface of the bending element is tilted in the direction in which the device is thinned, and further, the imaging elements are arranged in the direction in which the device is thinned, thereby reducing the thickness in the vertical direction. Is realized.

  Note that, by setting the imaging magnification of the imaging element to 1 or less and arranging the optical system so as to maintain the total reflection condition, horizontal downsizing and high recognition accuracy can be realized simultaneously.

  In addition, the optical pointing device adopts an assembly structure in passive alignment, so that it is possible to realize highly accurate assembly at a low cost, and it is possible to realize a module with good assemblability even if the size is reduced in the horizontal direction.

  Since the optical pointing device of the present invention is small and thin as described above, by adopting the device in an electronic device such as a portable information device, the electronic device can be reduced in size and thickness.

It is sectional drawing explaining the optical pointing device of 1st Embodiment of this invention. It is a figure for demonstrating the imaging optical system of the optical pointing device of 1st Embodiment of this invention. It is a figure for demonstrating the imaging optical system of the optical pointing device of 1st Embodiment of this invention. It is sectional drawing explaining the imaging optical system of the optical pointing device of 1st Embodiment of this invention. It is a figure for demonstrating the imaging optical system of the optical pointing device of 1st Embodiment of this invention. It is a figure for demonstrating the assembly method of the optical pointing device of 1st Embodiment of this invention. It is the figure which showed one Embodiment of the portable telephone using the optical pointing device of this invention.

  Hereinafter, an embodiment of the present invention will be described by taking an optical pointing device using an LED as a light source as an example. However, the light source may be natural light such as sunlight as long as it is an environment where external illumination is obtained.

  Further, the present invention is not limited to the configurations of the following embodiments.

  In the following description of the embodiments, members having the same function and action are denoted by the same reference numerals and description thereof is omitted.

(First embodiment)
FIG. 1 is a cross-sectional view for explaining the configuration of the first embodiment of the optical pointing device 1 of the present invention. 2, 3 and 4 are diagrams for explaining the optical system of the optical pointing device 1 according to the first embodiment of the present invention in the case where the fingertip 10 is used as a subject.

  An LED light source 17 is disposed below the optical path conversion element 12 as a light source for illuminating the fingertip 10 that is a subject.

  On the contact surface 11, the fingertip 10 that is a subject contacts. The fingertip 10 is illuminated with the illumination light indicated by the optical axis S1 emitted from the LED light source 17, and is scattered and reflected.

  The fingertip 10 forms a scattered reflection image, but a part of the scattered reflection light becomes imaging light indicated by optical axes Z1, Z2, and Z3 of the imaging optical system.

  The scattered reflection image of the fingertip 10 that is the subject is captured from the contact surface 11 that is the upper surface in the vertical direction of the prism 12 that is the first bending element, as indicated by the optical axis Z1 of the imaging optical system.

  As shown by the optical axis Z2 of the imaging optical system, the light taken in from the contact surface 11 is reflected, preferably totally reflected, by the first inclined surface 13 provided in the first bending element, and the first bending element. Is emitted.

  The light emitted from the first bending element enters the falling prism 23, which is the second bending element, via the lens 15, which is the imaging element.

  The light incident on the falling prism 23, which is the second bending element, is reflected by the second inclined surface 26 in the falling prism 23, preferably again by total reflection, as indicated by the optical axis Z3 of the imaging optical system. It is bent and emitted from the falling prism 23.

  The light emitted from the second bending element is formed as an image on the image sensor 16 by the action of the lens 15 and is taken in as image data to a DSP (Digital Signal Processor) 25 which is an image processing apparatus.

  Although it is desirable that the first inclined surface 13 and the second inclined surface 26 be substantially parallel, there is no problem even if they are slightly deviated from the parallel shape within a range where the aberration does not become a problem.

  The image sensor 16 is an image sensor such as a CMOS or a CCD, and continuously captures the image of the contact surface 11 at regular intervals. When the fingertip 10 that is the subject moves, the image that is captured is an image that is shifted by a predetermined amount from the image that was captured immediately before. The optical pointing device 1 compares the shift amount of the same part in the image with the DSP 25 as the image processing device, and determines the moving amount and moving direction of the subject.

  The prism 12 that is the first bending element of the present invention and the contact surface 11 can be formed integrally with the cover member of the optical pointing device 1 to reduce the thickness, and the first inclined surface 13 can be formed with high accuracy. As a result, the assembly of the optical pointing device is improved.

  The imaging lens 15 is configured integrally with a falling prism 23 that is a second bending element. With the structure in which the falling prism 23 is assembled to the cover member 24, the positional relationship among the prism surface 13, the imaging lens 15, and the falling prism 23 can be managed with high accuracy.

  The diaphragm 22 is affixed outside the effective surface of the imaging lens 15 in order to block stray light incident on the imaging lens 15.

  The image sensor 16 is integrally formed on a DSP 25 that is an image processing apparatus. Further, the DSP 25 as the image processing apparatus is bonded onto, for example, the circuit board 21 and sealed with a transparent resin mold 20b. The LED light source 17 is also bonded on the same circuit board 21 and sealed with the transparent resin mold 20a, but is separated from the transparent resin mold 20b, and the light from the LED light source 17 propagates through the transparent resin mold. This prevents the image sensor 16 from leaking.

  In addition, the board | substrate 21 with which the said LED light source 17 and the image pick-up element 16 are mounted is assembled in the passive alignment form which only contact | abuts the upper surface of transparent resin mold 20a, 20b with the said optical system.

  Here, in order to maintain the total reflection condition of the inclined surface 13 while shortening the optical path length, when the scattered reflected light from the fingertip 10 is incident on the inclined surface 13, the incident angle to the inclined surface 13 is the largest. The portion d in FIG. 2 which is smaller, that is, when entering from a direction close to the normal line of the inclined surface 13, is the most severe condition.

  Among the optical path lengths, the object side optical path length that is the object side optical path length from the imaging element 15 is L, the inclination angle of the first inclined surface 13 of the first bending element 12 and the contact surface 11 is α, and the bending element is refracted. When the rate is n, the shooting range of the subject on the contact surface 11 is a, and the tilt angle of the imaging optical system in the portion from the contact surface 11 to the first inclined surface 13 is φ, the object-side optical path length L is expressed by the following equation: It is necessary to satisfy the conditions of (2) to (4).

γ × (a / 2) × (COSφ + γ × SINφ) <L (2)
γ = TAN {90 ° −α + SIN ⁻¹ (1 / n)} (3)
φ = 2 × (45 ° −α) (4)
Note that L is expressed as an air equivalent distance.

  As shown in FIG. 2, the distance from the fingertip 10 to the center point of the first inclined surface 13 is A, the distance from the center point of the first inclined surface 13 to the center point of the exit surface 14 is B, and the exit surface 14. Where C is the distance from the center point of the lens 12 to the center point of the lens 12 that is the imaging element, the object side optical path length L is expressed by the following equation (5).

L = A / n + B / n + C (5)
By setting the object side optical path length L so as to satisfy the expression (2), the first inclined surface 13 can be made a total reflection surface, and the first inclined surface is subjected to a mirror treatment such as aluminum. There is no need.

  This not only can reduce the manufacturing cost of the prism 12 that is the first bending element, but also transmits the light from the LED light source 17 to the fingertip 10 that is the subject on the contact surface 11 through the first inclined surface 13. This makes it possible to reduce the size of the apparatus in the horizontal and vertical directions.

  For example, the inclination angle α of the first inclined surface 13 and the contact surface 11 is 45 °, a photographing range of the subject on the contact surface 11 is 0.7 mm, and the refractive index n of the first bending element is 1. ..59, L needs to have a length of 1.88 mm or more.

  Here, the object-side optical path length L can be shortened by making the angle α formed by the first inclined surface 13 and the contact surface 11 smaller than 45 °.

  For example, when α which is the inclination angle between the first inclined surface 13 and the contact surface 11 is 42 °, the object side optical path length L is 1.52 mm or more. The object side optical path length L can be shortened as compared to the value of the object side optical path length L of 1.88 mm or more in the case where α is 45 °.

  The smaller the a, which is the shooting range of the subject on the contact surface 11, can make the optical pointing device smaller and thinner, but the recognition accuracy deteriorates.

  The minimum value of a that is the shooting range of the subject on the contact surface 11 will be described. When the fingertip 10 in contact with the contact surface 11 is viewed from the X direction in FIG. 3 as shown in FIG. 3A, a black and white striped pattern due to a fingerprint image is observed as shown in FIG. .

  When the unevenness of the fingerprint is binarized as the density of scattered reflected light and expressed in black and white, it can be used as long as it can be judged as one fingerprint stripe, that is, black and white, for use as an optical pointing device. When the margin is considered and two are considered, that is, black and white, black and white, a is about 0.7 to 0.8 mm.

  Next, consider the relationship between the image side optical path length I, which is the optical path length from the imaging element 15 to the image sensor 16 side, and the object side optical path length L. Note that the image-side optical path length I at this time is an air equivalent distance as with the object-side optical path length L.

  As shown in FIG. 4, the distance from the top of the lens 15 that is the imaging element to the center point of the second inclined surface 26 is E, and the exit surface of the second bending element is from the center point of the second inclined surface 26. Is the distance from the center point of the exit surface of the second bending element to the center point of the imaging element 16, the refractive index of the falling prism is n1, and the refractive index of the transparent resin mold 20b is In the case of n2, the image-side optical path length I is expressed by the following formula (6).

I = E / n1 + F / n1 + G / n2 (6)
The distance G from the center point of the exit surface of the second bending element to the center point of the image sensor 16 is in the transparent resin mold 20b (not shown in FIG. 4), and therefore the refractive index of the transparent resin mold 20b. Divided by n2.

  Next, when the effective diameter of the imaging element 15 is D, the effective F number of the imaging optical system is Fe, and the imaging magnification is M, the object-side optical path length L and the image-side optical path length I are as follows: There is a relationship of (7) and Formula (8).

D = L × M × COSφ / Fe (7)
M = I / L (8)
Here, in order to reduce the size of the optical pointing device in the vertical direction, the effective diameter of the imaging element 15 is preferably smaller than the shooting range a of the subject on the contact surface 11, and it is necessary to satisfy the following formula (9): There is.

D <a (9)
Therefore, the following equation (10) is obtained from the equations (7) and (9).

L <a × Fe / M × COSφ (10)
Here, the effective F number Fe is a value determined by the imaging sensitivity of the imaging device 16, but is 5 or less in a general imaging device that is not highly sensitive.

  Further, in order to shorten the optical path length of the entire imaging optical system and reduce the size of the optical pointing device in the horizontal direction, the imaging magnification M needs to satisfy the following expression (11).

M <1 (11)
By satisfying Expression (11), the image-side optical path length I is smaller than the object-side optical path length L, and the optical path length of the entire imaging optical system can be shortened.

  This is nothing but reducing the image-side optical path length I by using the imaging element 16 having an effective imaging area of a size smaller than the imaging range a of the subject on the contact surface.

  In general, the optical pointing device recognizes the movement of the concave and convex portions of the fingerprint, and the photographing range a of the subject on the contact surface 11 is preferably 0.7 to 0.8 mm for the reason of determining the movement of the fingerprint. Therefore, when the width of the effective imaging area of the image sensor 16 is H, the width H of the effective imaging area is 0.7 mm or less, which is smaller than the shooting range a of the subject on the contact surface 11, from the viewpoint of downsizing the optical pointing device. It is desirable to make it.

  For example, when a = 0.7 mm, Fe = 3.2, H = 0.56 mm, and α = 42 °, the imaging magnification M is obtained by dividing the effective imaging area width H by the subject imaging range a on the contact surface 11. It becomes 0.8. Therefore, L is less than 2.81 mm from the equation (10).

  That is, the module can be downsized in the horizontal and vertical directions by setting the object side optical path length L in the range of 1.52 mm to 2.81 mm in combination with the total reflection condition described above.

  In the above example, the angle between the first inclined surface 13 and the contact surface 11 has been described in the range of 42 ° to 45 °. However, in the experiment and simulation, if the lower limit is up to 40 °, coma aberration can be allowed. It was. On the other hand, in the example, when the angle formed by the first inclined surface 13 and the contact surface 11 is larger than 45 °, the thickness of the first inclined surface 13 is thicker than that of the conventional technique, and the optical pointing device is not thinned. . Therefore, the angle formed by the first inclined surface 13 and the contact surface 11 is 40 ° to 45 °.

  Also, as shown in FIG. 5, the angle formed between the first inclined surface 13 and the contact surface 11 is made smaller than 45 °, so that the lens 15 as the imaging element is viewed from the thickness direction of the optical pointing device. It becomes possible to arrange in the high position which means the side.

  FIG. 5A is an explanatory diagram of the optical system when the angle formed between the first inclined surface 13 and the contact surface 11 is 45 °, and FIGS. 5B and 5C are the first inclined surface. It is a figure explaining the arrangement | positioning of an optical system when it is a case where the angle which 13 and the contact surface 11 comprise is less than 45 degrees, and is 40 degrees as an example.

  Z0 is the optical axis of the lens 15 that is an imaging element, and coincides with the normal line of the surface top of the lens 15. Z1 to Z3 indicate optical paths through which the chief ray emitted from the center of the fingertip 10 as the subject passes.

  FIG. 5B shows an optical system so that the optical axis Z0 of the lens 15 which is an image sensor coincides with the angle formed by the first inclined surface 13 and the contact surface 11 in FIG. In FIG. 5C, the optical axis Z0 of the lens 15 that is the image sensor is positioned higher than when the angle formed between the first inclined surface 13 and the contact surface 11 is 45 °. The case where it arranges is shown.

  Ya to Yc shown in FIGS. 5A to 5C indicate distances in the thickness direction from the contact surface 11 to the back surface of the image sensor 16 related to the thinning of the optical pointing device 1. Although Ya and Yb are substantially the same distance, Yc is shortened by the amount by which the optical axis Z0 of the lens 15 that is the imaging element is moved upward in the thickness direction of the present optical pointing element.

  That is, the angle formed between the first inclined surface 13 and the contact surface 11 is made smaller than 45 °, and the tilt angle φ of the optical path Z1 of the imaging optical system in the portion from the contact surface 11 to the first inclined surface 13 is substantially 0. When the optical arrangement shown in FIG. 5C is reduced so that the angle is .degree., The lens 15 as the imaging element passes through the first light paths Z1 and Z2 of the principal rays emitted from the center of the fingertip 10 as the subject. It is arranged at a position higher than the center of the inclined surface. As a result, the image pickup device 16 can also be arranged at a high position that means the subject side as viewed from the thickness direction of the optical pointing device, and the optical pointing device 1 can be thinned.

  Further, as can be seen by comparing FIG. 5B and FIG. 5C, reducing the tilt angle φ of the optical path Z1 of the imaging optical system in the portion from the contact surface 11 to the first inclined surface 13 is This also leads to a reduction in the horizontal length of the imaging optical system, and the optical pointing device 1 can be reduced in thickness and size.

  In the above description, the tilt angle φ is approximately 0 °. However, FIG. 5B shows the state of the equation (4), and the tilt angle φ is changed from 0 ° to the equation (4). The effect of the present invention can be obtained as long as the range is satisfied.

  Although the imaging element 15 has been described using a lens in the present embodiment, a pinhole may be used in addition to the lens. When a pinhole is used, the imaging element 15 can be made thin, which is advantageous for downsizing. On the other hand, when a lens is used, more light can be captured with a small size, so that the brightness of the obtained image can be increased and the signal-to-noise ratio can be increased.

  As described above, in the optical pointing device 1 of the present invention, it is possible to reduce the size of the device in the horizontal and vertical directions while using the first inclined surface 13 of the prism 12 as the first bending element as a total reflection surface.

  Next, assembly of the optical pointing device of the present invention will be described with reference to FIG.

  On the circuit board 21 of the optical pointing device, the image sensor 16, the DSP 25 as the image processing device, and the LED light source 17 are mounted, and the member sealed with the transparent resin molds 20 a and 20 b is used as the optical pointing device lower part 1 b. The other members are referred to as an optical pointing device upper portion 1a.

  6A and 6B are perspective views of the optical pointing device upper portion 1a as viewed from the back side, which is the image sensor side. Further, (a) shows the cover member 24 before the falling prism 23 and the diaphragm 22 are assembled, and (b) shows the cover member 24 after the falling prism 23 and the diaphragm 22 are assembled. FIG. 6C is a perspective view of the lower part 1b of the optical pointing device as viewed from the surface side that is the subject direction.

  The upper part 1a of the optical pointing device is composed of a cover member 24 in which a prism 12 as a first bending element is integrally formed, a falling prism 23, and a diaphragm 22. The optical pointing device lower portion 1b is composed of components other than the optical pointing device upper portion 1a.

  The cover member 24 is integrally formed with first tapered portions 24a, 24b, 24c that engage with the second inclined surface of the second bending element, and a mounting surface 24e that engages with the optical pointing device lower portion 1b. .

  Further, the tapered portion 24a is provided with a counterbore 24d in order to maintain the total reflection condition in the portion where the imaging light is irradiated on the second inclined surface of the second bending element, thereby securing an air layer. ing.

  The falling prism 23 is integrally formed with second tapered portions 23b and 23c and a lens edge surface 23d.

  The 1st taper part 24b and the 2nd taper part 23b are parallel. Similarly, the first tapered portion 24c and the second tapered portion 23c, and the second inclined surface 26 and the first tapered portion 24a are also parallel.

  The assembly of the optical pointing device upper portion 1a is performed by fitting the second tapered portion with the first tapered portion.

  A diaphragm 22 is attached to the lens edge surface 23d of the falling prism 23, the second tapered portion 23b and the first tapered portion 24b, the second tapered portion 23c and the first tapered portion 24c, and the second inclined surface 26. After the first taper portion 24a and the first taper portion 24a are combined, an adhesive is applied to a portion other than the contact portion except the counterbore 24d portion for ensuring the total reflection, and the state shown in FIG. 6B is completed. .

  The second taper portion 23b and the first taper portion 24b, and the second taper portion 23c and the first taper portion 24c are combined, whereby the prism 12 and the falling prism 23 are positioned in the vertical direction, and the second inclined surface. Positioning in the horizontal direction is performed by combining a portion not participating in total reflection of 26 with the first tapered portion 24a.

  Each of the tapered portions is formed integrally with the cover member 24 corresponding to the casing and the second bending element, so that it can be manufactured with a tolerance of 20 microns or less as a single unit, and the total assembly tolerance is a mean square. High accuracy of 30 microns or less can be realized.

  Further, since the tapered portions are fitted together, positioning is performed semi-automatically, and assembly can be easily performed without requiring skill.

  Furthermore, in order to reduce malfunctions due to external light, even when a thin light shielding plate is provided between the falling prism 23, which is the second bending element, and the cover member 24 in a form that does not affect total reflection, positioning is performed at the tapered portion. Therefore, there is no influence such as a thickness error of the light shielding plate.

  After assembling the optical pointing device upper part 1a, it is fitted so that the mounting surface 24e of the optical pointing device upper part 1a contacts the sealing resins 20a and 20b of the optical pointing apparatus lower part 1b shown in FIG. The entire assembly process is completed simply by bonding.

  Although not shown, the optical resin is easily and accurately aligned with respect to the effective area of the image sensor 16 by fitting the sealing resins 20a and 20b and the cover member 24 into a taper. I can do it.

  In the present embodiment, the tapered surface is used for passive alignment between the components. However, the present invention is not limited to this, and high-precision positioning and assembly can be performed using a fitting method using pins and holes. .

(Second embodiment)
In the second embodiment, a case where the optical pointing device of the present invention is mounted on a portable telephone which is a portable information terminal will be described as an electronic apparatus employing the optical pointing device of the present invention.

  (A) to (c) of FIG. 7 are diagrams showing the configuration of the mobile phone. 7A is a front side of the mobile phone 100, FIG. 7B is a back side of the mobile phone 100, and FIG. 7C is a side view of the mobile phone 100. On the side.

  A mobile phone 100 according to this embodiment includes a monitor-side casing 101, an operation-side casing 102, a microphone unit 103, a numeric keypad 104, a monitor unit 105, a speaker unit 106, and the optical pointing device 107 of the present invention. Yes.

The speaker unit 106 and the microphone unit 103 are used for inputting and outputting audio information. The monitor unit 105 is used to output video information. In the third embodiment, the monitor unit 105 is also used to display input information from the optical pointing device 107. In the third embodiment, the optical pointing device is used. Although 107 is arranged on the upper part of the numeric keypad 104 shown in FIG. 7A, the arrangement method and the direction of the optical pointing device 107 are not limited to this.

  The mobile phone 100 according to the third embodiment is a so-called mobile phone 100 in which an upper housing and a lower housing are connected via a hinge, as shown in FIGS. 7 (a) to 7 (c). Although the folding portable phone 100 is taken as an example, the portable phone 100 on which the optical pointing device 107 can be mounted is not limited to the folding type.

  However, in portable telephones, the folding type is the mainstream as in this embodiment, and those with a thickness of 10 mm or less in the folded state have also appeared. If portability is taken into account, its thickness is an extremely important factor along with downsizing.

In the operation-side casing 102 shown in the rear view (b) and the side view (c) of FIG. 7, components that determine the thickness of the operation-side casing 102 excluding an internal circuit board (not shown)
The optical pointing device 107 is obtained. Among these, the thickness of the optical pointing device 107 is the largest, and the area occupied by buttons and the like is also large. The downsizing and thinning of the optical pointing device 107 directly leads to the downsizing and thinning of the mobile phone 100. Therefore, the optical pointing device of the present invention is an invention suitable for reducing the size and thickness of the mobile phone 100.

1 Optical pointing device
1a Optical pointing device upper part 1b Optical pointing device lower part 10 Fingertip (subject)
11 Contact surface
12 First bending element (prism)
13 First inclined surface 14 Output surface
15 Imaging element (lens)
16 Image sensor 17 LED light source
20a, 20b Transparent resin mold
21 Circuit board
22 Aperture
23 Second bending element (falling prism)
23b, 23c 2nd taper part 23d Lens edge surface 24 Cover member
24a, 24b, 24c First taber portion 24d Counterbore 24e Mount surface 25 Image processing device (DSP)
26 Second inclined surface 100 Mobile phone 101 Monitor side case 102 Operation side case 103 Microphone part 104 Numeric keypad 105 Monitor part 106 Speaker part 107 Optical pointing device

Claims (4)

The contact surface that the subject touches,
A first bending element having a first inclined surface for bending a light beam emitted from the subject;
An imaging element for imaging the bent light beam as an image;
A second bending element having a second inclined surface for bending the imaging light from the imaging element;
An image sensor for imaging the imaging light;
Said first inclined surface, the angle formed between the contact surface, Ri range near the 45 ° from 40 °,
An optical pointing device , wherein an optical axis of the imaging element is on the contact surface side with respect to a center of the first inclined surface through which a principal ray emitted from the center of the subject passes . The contact surface that the subject touches,
A first bending element having a first inclined surface for bending a light beam emitted from the subject;
An imaging element for imaging the bent light beam as an image;
A second bending element having a second inclined surface for bending the imaging light from the imaging element;
An image sensor for imaging the imaging light;
The first inclined surface has an angle formed with the contact surface in a range of 40 ° to 45 °,
The imaging element is provided in a configuration that can be integrally molded with the second bending element,
The air conversion distance between the contact surface and the imaging element satisfies the following formula (1):
An optical pointing device, wherein an imaging magnification of the subject is 1 or less.
γ × (a / 2) × (COSφ + γ × SINφ) <L <a × Fe / (M × COSφ) (1)
(Where α is an angle formed by the first inclined surface and the contact surface, n is a refractive index of the first bending element, a is a photographing range of the subject on the contact surface, and φ is 2 × (45 ° −α ), Fe is the effective F number of the imaging element, M is the imaging magnification of the optical pointing device, and γ is TAN (90 ° −α + SIN ⁻¹ (1 / n)). The first bending element is formed integrally with the cover member,
3. The optical pointing device according to claim 1, wherein the second bending element is assembled with respect to the first bending element by passive alignment in both a height direction and an optical axis direction. An electronic apparatus comprising the optical pointing device according to any one of claims 1 to 3.