KR100802418B1 - Low power optical pointing apparatus and personal portable device having the same - Google Patents

Abstract

The present invention provides a low power optical pointing device and a personal portable terminal having the same. The present invention provides a transparent cover plate having a central leading area for contacting a subject; EL sheet for irradiating light to the subject in contact with the cover plate while emitting light by the applied power; Light guide means for condensing the light reflected from the subject in a predetermined direction; It is provided with an ultra-high sensitivity image sensor for detecting a change in the light emitted from the light guide means and converting it into an electrical signal. The EL sheet is disposed on the bottom surface of the cover plate, and is disposed along an edge circumference except for a leading region of the center, and the ultra-high sensitivity image sensor is a sensor capable of recognizing an image at an illuminance of 0.1 lux or less. According to the present invention, since the ultra-sensitivity image sensor capable of efficiently detecting low illuminance light is used, an EL sheet that generates low luminance light can be used as a light source, and an EL sheet having low luminance can be used as a light source. As a result, power consumption can be minimized and power consumption can be minimized, thereby extending the battery life of a personal portable terminal.

Description

LOW POWER OPTICAL POINTING APPARATUS AND PERSONAL PORTABLE DEVICE HAVING THE SAME}

1 to 4 show a conventional optical pointing devices,

5 is a view showing the configuration of a low power optical pointing device according to the present invention;

6 is an operation diagram showing the operation of the low-power optical pointing device according to the present invention, Figure 7 is a bottom perspective view showing a cover plate and EL sheet constituting the low-power optical pointing device of the present invention,

8 to 10 are perspective views showing a modification of the EL sheet constituting the low power optical pointing device of the present invention,

11 to 15 are views showing modifications of the light guide means constituting the low power optical pointing device of the present invention,

16 is a perspective view showing a personal portable terminal provided with a low power optical pointing device of the present invention.

♣ Explanation of symbols for the main parts of the drawing ♣

100: cover plate 110: reading area

200: EL sheet 300: light guide means

310: first waveguide 312: incident surface

314: reflective surface 316: exit surface

320: second waveguide 322: incident surface

324: reflective surface 326: exit surface

330: blocking aperture 400: ultra-sensitivity image sensor

500, 600, 700, 800, 900: light guide means 510: reflector

520: condenser lens 610: first reflecting mirror

620: condenser lens 630: second reflecting mirror

710: curved reflector 712: reflective surface

810: curved reflector 812: reflective surface

820: condenser lens 910: first curved reflector

912: reflecting surface 920: second curved reflecting mirror

922: reflective surface 1000: personal mobile terminal

1100: terminal body 1200: low power optical pointing device

The present invention relates to an optical pointing device used as a user interface device of a personal portable terminal, and more particularly, a low-power light source capable of using a low brightness light source and minimizing current consumption by using a low brightness light source. The present invention relates to a pointing device and a personal terminal having the same.

Personal digital assistants, such as mobile phones and PDAs (Personal Digital Assistants), add various functions beyond simple functions such as telephone calls, schedule / address management, and data accumulation. In particular, wireless internet service functions, game functions, and camera functions have recently been added.

On the other hand, such a portable terminal essentially adopts a graphical user interface (GUI) environment in order to smoothly operate various additional functions, and an optical pointing device has been proposed as an input device suitable for the GUI environment.

As shown in FIG. 1, the optical pointing device includes a light source 1, an optical guide 5 for guiding light from the light source 1 to the subject F, and light reflected from the subject 5. It consists of a lens 7 for condensing the light, and an image sensor 8 for detecting a change in the collected light and converting the light into an electrical signal. Here, the light source 1 uses a light emitting diode (LED) and the CMOS (Complementary Metal Oxide Semiconductor) sensor is used as the image sensor 8.

According to such an optical pointing device, the light source 1 emits light by electricity applied. Then, the light of the light source 1 is irradiated to the subject (F), that is, the user's finger through the light guide 5, the irradiated light is irradiated to the lens 7 of the lower side while being reflected on the subject (F), The irradiated light is condensed by the lens 7 and is imaged on the image sensor 8.

When the subject F moves in such a state, the light reflected from the subject F changes according to the movement, and the image formed in the image sensor 8 changes according to the change of the light. As a result, the image sensor 8 converts the changed image into an electrical signal and inputs it to a data processing unit (not shown) of the personal portable terminal, and the data processing unit to which the electrical signal is input is based on this. Convert motion to two-dimensional data.

By the way, the optical pointing device having such a configuration is an input device which is very suitable for the "GUI environment" in that the motion of the subject F is converted into two-dimensional data, but due to its structural characteristics, the optical pointing device has a lot of difficulties in slimming the device. Therefore, a problem has been pointed out that it cannot be employed in personal portable terminals requiring slimming.

That is, in order to slim down the optical pointing device, it is important to shorten the focal length l of the lens 7 to reduce the distance between the lens 7 and the image sensor 8. However, when the focal length ℓ of the lens 7 is shortened, the imaging angle α formed on the image sensor 8 increases, and as the imaging angle α increases, the depth of focus becomes shallow, and the depth of focus becomes shallow. If the image sensor 8 deviates even slightly from the depth of focus due to assembly tolerances or design errors in accordance with the load, an accurate image is not formed in the image sensor 8. Therefore, there is a problem in that the change of the light reflected from the subject F cannot be detected accurately.

As a result, there is a lot of difficulty in making the device slimmer by shortening the focal length ℓ of the lens 7 due to the structural characteristics of the lens 7. Therefore, a conventional optical pointing device is applied to a personal portable terminal requiring slimming. I cannot adopt it.

On the other hand, in view of this, the present applicant has proposed an ultra-slim optical joystick device capable of making the device slimmer and precisely recognizing the movement of the subject F. Patent applications 2004-113266, 2005-5935, It was filed in 2005-5936.

As described in Patent Application No. 2004-113266, as shown in FIG. 2, a light source 10, a reflector 14 reflecting light from the light source 10 to the object contact cover plate 12, and a subject F The first waveguide 15 for condensing the light of the light source 10 reflected from the light source 10 in a horizontal direction, and the second waveguide 17 for refracting the light refracted and focused in the horizontal direction back to the vertical direction, and The image sensor 18 detects a change in light emitted from the two waveguides 17 and converts the light into an electrical signal. The light source 10 uses a light emitting diode (LED) and the CMOS sensor is used as the image sensor 18.

As shown in FIG. 3A, the technique of Patent Application No. 2005-5935 includes a light source 20 and a first and second guide reflector 24 reflecting light from the light source 20 to a subject contact cover plate 22. , 25, a reflector 26 for reflecting light of the light source 20 reflected from the subject F in the horizontal direction, a condenser lens 27 for condensing the light reflected from the reflector 26, and a condenser lens And an image sensor 28 that detects a change in light emitted from the light 27 and converts the light into an electrical signal.

On the other hand, Fig. 3B is a technique showing a modification of Patent Application No. 2005-5935, and further includes a second reflector 29 for reflecting light emitted from the condenser lens 27 vertically downward again. Of course, in this case, the image sensor 28 is disposed below the second reflecting mirror 29.

As described in Patent Application No. 2005-5936, as shown in FIG. 4A, the first and second guide reflectors 34 reflecting the light source 30 and the light from the light source 30 to the subject contact cover plate 32. , 35), the curved reflector 36 for condensing while reflecting the light of the light source 30 reflected from the subject F in the horizontal direction, and the electric signal by detecting the change of the reflected light from the curved reflector 36 It consists of an image sensor 37 to convert to.

On the other hand, Fig. 4B is a technique showing a modification of Patent Application No. 2005-5936, and further includes a condenser lens 38 for condensing the light reflected from the curved reflector 36.

4C shows another modification of Patent Application No. 2005-5936 and further includes a second curved reflector 39 for reflecting light reflected from the curved reflector 36 back vertically downward. Of course, in this case, the image sensor 37 is disposed below the second curved reflector 39.

The ultra-slim optical joystick devices having such a configuration change the path of light reflected from the subject F in the horizontal direction, thereby significantly reducing the thickness of the device compared to the conventional optical point device in which the light path is vertical. Therefore, it can be installed in a personal portable terminal requiring slimming.

In addition, the ultra-slim optical joystick device can increase the focal length by changing the path of light in the horizontal direction, and maintain the depth of focus as the focal length is increased to provide an accurate image to the image sensors 18, 28 and 37. Allow to form an image.

However, since such a ultra-slim optical joystick device uses a CMOS sensor as the image sensors 18, 28 and 37, a large amount of incident light is required and a large amount of incident light is required. It is pointed out that there is no choice but to use a high brightness light emitting diode. In particular, since a high brightness light emitting diode is used, many driving currents are consumed, and thus, there is a disadvantage in that the battery of the personal portable terminal is consumed early.

SUMMARY OF THE INVENTION The present invention has been made to solve the above disadvantages, and an object thereof is to provide a low power optical pointing device capable of precisely recognizing the movement of a subject even with a small amount of incident light and a personal portable terminal having the same.

Another object of the present invention, since it is possible to recognize the movement of the subject even with a small amount of incident light, it is possible to use a light source of low brightness, low power optical pointing device that can minimize the current consumption by using a light source of low brightness and It is to provide a personal portable terminal having the same.

In order to achieve the above object, the present invention is a transparent cover plate having a central leading area portion that can contact the subject; An EL sheet which emits light by an applied power and irradiates light onto a subject in contact with the cover plate; Light guide means for condensing the light reflected from the subject in a predetermined direction; And an ultra-sensitivity image sensor for detecting a change in light emitted from the light guide means and converting the light into an electrical signal.

Preferably, the EL sheet is disposed on a bottom surface of the cover plate, and is disposed along an edge circumference except for a leading region of the center, and the ultra-sensitivity image sensor is an image at an illuminance of 0.1 lux or less. Is a sensor that can be used.

And the light guide means includes an incident surface for inciding light reflected from the subject, a reflective surface for redirecting the incident light at a 45 ° angle, and a convex output surface for condensing the redirected light. 1 waveguide; And a second waveguide having a convex incidence surface for incident light emitted from the first waveguide, a reflection surface for redirecting the incident light at an angle of 45 °, and a exit surface for emitting the redirected light. It is done.

Hereinafter, a preferred embodiment of a low power optical pointing device and a personal portable terminal having the same according to the present invention will be described in detail with reference to the accompanying drawings.

First, referring to FIGS. 5 and 6, the optical pointing device of the present invention includes a cover plate 100. The cover plate 100 is configured to contact the subject F, ie, the user's finger, and is transparent to allow light to pass therethrough.

In addition, the optical pointing device of the present invention includes a light source 200 disposed under the cover plate 100. The light source 200 is composed of EL sheets and emits light by an applied power source. In particular, the emitted light is irradiated onto the subject F in contact with the cover plate 100.

For reference, the EL sheet (Electro Luminescence Sheet) is a phosphor coated on the organic film, has a configuration that emits light by an applied power source, and has a characteristic that can be driven at low voltage. In particular, they are driven at low voltages, minimizing power consumption. Since the configuration and operation of the EL seat 200 is already known, a detailed description thereof will be omitted.

Meanwhile, the EL sheet 200 is disposed along the bottom edge of the cover plate 100, for example, as illustrated in FIGS. 5 to 7. In particular, it is disposed in the shape of an annular shape along the periphery of the bottom edge except for the central portion 110 of the cover plate 100. Accordingly, the emitted light may pass through the central portion 110 of the cover plate 100 to be irradiated to the bottom surface of the subject F. FIG.

Here, the center portion 110 of the cover plate 100 is a portion in which the subject F is in direct contact, and is a kind of “reading region portion” for directly detecting the movement of the subject F. FIG. Hereinafter, the central portion 110 of the cover plate 100 will be referred to as a "reading region portion 110".

Meanwhile, FIGS. 8 to 10 are views illustrating modified examples of the EL sheet 200. In the modified example of FIG. 8, the EL sheet 200 is disposed along the bottom edge of the cover plate 100, but has only a portion of the edge.

In addition, the modification of FIG. 9 has a configuration in which the EL sheet 200 is disposed along the side circumference of the cover plate 100. In this case, the EL sheet 200 may be disposed in an annular shape along the side circumference of the cover plate 100, and in some cases, may be disposed only in a part of the circumference of the side.

In addition, the modification of FIG. 10 has a configuration in which the EL sheet 200 is disposed along the periphery of the top surface of the cover plate 100. In this case, the EL sheet 200 may be disposed in an annular shape (donut shape) around the upper edge of the cover plate 100, and in some cases, may be disposed only on a portion of the upper edge of the cover plate.

Meanwhile, in the drawings of the present invention, the cover plate 100 is shown in a circular shape, and the EL sheet 200 is formed in an annular shape or a curve having a predetermined curvature, but is not limited thereto. For example, the cover plate 100 ) May be configured in the shape of a square, that is, a quadrangle, and may be configured in the shape of a strip of a corresponding square, or may be configured in a straight line corresponding to one side of the square.

Referring again to FIGS. 5 and 6, the optical pointing device of the present invention includes optical guide means 300 for guiding light in the EL sheet 200 reflected from the subject F while guiding in a predetermined direction. do.

The light guide means 300 refracts the light emitted from the first waveguide 310 and the first waveguide 310 to collect light while refracting the light reflected vertically downward from the subject F in the horizontal direction. Consisting of a second waveguide 320.

The first waveguide 310 has an entrance face 312, a reflection face 314, and an exit face 316. The incident surface 312 is disposed to correspond to the vertical lower portion of the cover plate 100, and incident the reflected light of the subject F passing through the cover plate 100. Reflecting surface 314 is arranged at an angle of approximately 45 ° with respect to incident surface 312, and reflects the incident light at approximately 45 ° angle. Therefore, the light reflected vertically downward from the subject F is refracted in the horizontal direction. The exit surface 316 forms a flat convex lens surface. Therefore, the emitted light is focused at a predetermined angle.

The second waveguide 320 is arranged on the same axis as the first waveguide 310 and has an incident surface 322, a reflective surface 324, and an exit surface 326. The incident surface 322 is disposed to correspond to the exit surface 316 of the first waveguide 310 at an interval, and forms a flat convex lens surface and is emitted from the exit surface 316 of the first waveguide 310. Make light incident Reflecting surface 324 is arranged at an angle of approximately 45 ° with respect to incident surface 322 and reflects the incident light approximately 45 ° vertically below. Therefore, the light incident in the horizontal direction is refracted vertically downward. The exit surface 326 emits the refracted light vertically downward.

Meanwhile, a blocking stop 330 is disposed between the first waveguide 310 and the second waveguide 320. The blocking stop 330 blocks ambient noise light of light emitted from the exit surface 316 of the first waveguide 310.

According to the light guide means 300 of such a configuration, it is possible to reduce the thickness of the device by guiding the light reflected from the subject (F) in the horizontal direction. In addition, by condensing the light reflected from the subject F, an accurate image may be formed in the super-sensitivity image sensor 400 described later.

Referring again to FIGS. 5 and 6, the optical pointing device of the present invention includes an ultra-high sensitivity image sensor 400 disposed under the vertical bottom of the exit surface 326 of the second waveguide 320.

The ultra-high sensitivity image sensor 400 is composed of a sensor having a sensitivity significantly superior to a CMOS sensor, for example, a nu mycoicon (νMAICOVICON) sensor or a high sensitivity nano image sensor (SMPD). The change in the light emitted from the exit surface 326 of the second degree pipe 320 is detected and converted into an electrical signal.

For reference, NUMAICOVICON sensor is an ultra-sensitivity image sensor developed based on CMOS sensor by "Matsushita" in Japan, and high-sensitivity nano image sensor (SMPD) is developed by KETI in Korea. It is a developed ultra high sensitivity image sensor. These ultra-high sensitivity image sensors have a sensitivity of about 10 to 1000 times or more than a general image sensor, for example, a CMOS sensor, and can recognize an image even at an illuminance of less than 0.1 lux. Accordingly, it is possible to detect the light of the EL sheet 200 having a relatively low amount of light. Since the configuration and operation of the nu my beacon ultra-high sensitivity image sensor and the high sensitivity nano image sensor (SMPD) is already known, a detailed description thereof will be omitted.

Next, an operation example of the present invention having such a configuration will be described with reference to FIG. 6. First, the EL sheet 200 emits light by an applied power source. Then, while the light of the EL sheet 200 passes through the cover plate 100, the subject F, ie, the user, which is in contact with the leading region 110 of the cover plate 100 is irradiated to the finger.

The light irradiated onto the subject F is incident on the incident surface 312 of the first waveguide 310 at the lower side while being reflected by hitting the subject F, and the incident light is horizontally directed through the reflecting surface 314. Is refracted, and the refracted light is focused while passing through the emission surface 316.

The condensed light is incident on the incident surface 322 of the second waveguide 320, and the incident light is refracted vertically again through the reflecting surface 324, and the refracted light is emitted through the emitting surface 326. The light is emitted vertically downward and is imaged on the ultra-high sensitivity image sensor 400.

Meanwhile, when the subject F moves in such a state, the light reflected from the subject F changes according to the movement, and the image formed by the ultra-high sensitivity image sensor 400 changes according to the change of the light. Accordingly, the ultra-high sensitivity image sensor 400 converts the changed image into an electrical signal and inputs it to a data processing unit (not shown) of the personal portable terminal, and the data processing unit to which the electrical signal is input is based on the subject F. ) Motion is converted into two-dimensional data.

According to the low-power optical pointing device of the present invention having the configuration as described above, the EL sheet 200 which generates light of low luminance because the ultra-high sensitivity image sensor 400 which can efficiently detect low light intensity is used. Can be used as a light source. In addition, since the EL sheet 200 can be used as a light source, power consumption can be minimized, and battery consumption of the personal portable terminal is delayed by minimizing power consumption.

Next, FIGS. 11 to 15 are views showing modifications of the light guide means constituting the optical pointing device of the present invention.

The light guide means 500 of the first modification shown in FIG. 11 includes a reflector 510 arranged at an angle of about 45 ° below the cover plate 100 in a vertical direction, and a light condenser disposed in front of the reflector 510. It consists of a lens 520.

The reflector 510 reflects the light reflected from the subject F at an angle of about 45 ° and converts the light in the horizontal direction. The condenser lens 520 condenses the light converted in the horizontal direction and provides it to the ultra-high sensitivity image sensor 400. Since the optical guide means 500 of such a 1st modification has a simple structure, it is easy to manufacture and manufacturing cost is low.

In addition, the optical guide means 600 of the second modified example shown in FIG. 12 includes a first reflecting mirror 610 and an inclination of the first reflecting mirror 610 which are arranged to be inclined at an angle of about 45 ° vertically downward of the cover plate 100. A condenser lens 620 disposed in front and a second reflecting mirror 630 disposed obliquely downward by approximately 45 ° in front of the condenser lens 620.

The first reflector 610 reflects the light reflected from the subject F at an angle of about 45 ° and converts the light in the horizontal direction. The condenser lens 620 condenses the light converted in the horizontal direction. In addition, the second reflector 630 converts the collected light to a vertical downward angle of about 45 ° and provides the ultra-high sensitivity image sensor 400.

Since the optical guide means 600 of the second modification has a structure in which the image sensors 400 can be arranged horizontally, the optical guide means 600 can be stably installed.

And the light guide means 700 of the third modification shown in FIG. 13 is composed of a curved reflector 710 disposed below the cover plate 100 vertically.

The curved reflector 710 has a reflecting surface 712 arranged to be inclined at an approximately 45 ° angle with respect to the cover plate 100. The reflective surface 712 is a concave surface having a predetermined curvature and condenses the light reflected from the subject F while switching in the horizontal direction. Therefore, the collected light is provided to the ultra-high sensitivity image sensor 400.

In addition, the light guide means 800 of the fourth modified example illustrated in FIG. 14 includes a curved reflector 810 disposed vertically downward of the cover plate 100, and a condenser lens 820 disposed in front of the curved reflector 810. It is composed of

The curved reflector 810 has a reflecting surface 812 that is inclined at an approximately 45 ° angle with respect to the cover plate 100. The reflecting surface 812 is a concave surface having a predetermined curvature and condenses the light reflected from the subject F while switching in the horizontal direction.

The condenser lens 820 secondly condenses the light converted in the horizontal direction and provides the condensed light to the ultra-high sensitivity image sensor 400.

The light guide means 800 of the fourth modified example further includes a condenser lens 820 for secondly condensing the light reflected from the curved reflector 810, thereby maximizing the condensing efficiency of light. Have

In addition, the optical guide means 900 of the fifth modified example illustrated in FIG. 15 is disposed in front of the first curved reflector 910 and the first curved reflector 910 disposed vertically below the cover plate 100. The second curved reflector 920 is formed.

The first curved reflector 910 has a reflecting surface 912 arranged to be inclined at an angle of approximately 45 ° with respect to the cover plate 100. The reflecting surface 912 is a concave surface having a predetermined curvature and condenses the light reflected from the subject F while switching in the horizontal direction.

The second curved reflector 920 has a reflecting surface 922 arranged to be inclined at an angle of about 45 ° downward with respect to the reflecting surface 912 of the first curved reflecting mirror 910. The reflective surface 922 is a concave surface having a predetermined curvature, and re-condenses while converting light reflected from the first curved reflector 910 vertically downward. Thus, the collected light is provided to the ultra-high sensitivity image sensor 400.

Since the optical guide means 900 of the fifth modification has a structure in which the image sensors 400 can be arranged horizontally, the optical guide means 900 can stably install the image sensors 400.

Next, FIG. 16 shows a personal portable terminal 1000 in which the low power optical pointing device of the present invention is installed. Accordingly, the personal portable terminal 1000 includes a terminal body 1100, and the low power optical pointing device 1200 of the present invention is installed in the terminal body 1100.

In this case, the cover plate 100 of the low power optical pointing device 1200 is installed on the outer surface of the terminal body 1000. Therefore, the user can move while touching the finger. The ultra-high sensitivity image sensor 400 (see FIG. 3) of the low power optical pointing device 1200 is electrically connected to a data processor (not shown) of the personal portable terminal 1000. Therefore, the electrical signal according to the movement of the finger is input to the data processor.

Although the preferred embodiments of the present invention have been described above by way of example, the scope of the present invention is not limited to these specific embodiments, and may be appropriately changed within the scope of the claims.

As described above, the low-power optical pointing device and the personal portable terminal having the same use an ultra-sensitivity image sensor capable of efficiently detecting low-illuminance light, thereby generating low luminance light. The sheet can be used as a light source, and the low-luminance EL sheet can be used as a light source to minimize power consumption and to minimize power consumption, thereby delaying battery consumption of a personal mobile terminal. Has an effect.

Claims (13)

A transparent cover plate having a central leading area portion capable of contacting a subject; Optical guide means comprising a first waveguide for condensing light reflected vertically downward from the subject in a horizontal direction, and a second waveguide for refracting light emitted from the first waveguide in a vertical direction again; In the low-power optical pointing device for converting the light path in the horizontal direction comprises an ultra-sensitive image sensor for detecting a change in the light emitted from the light guide means to convert into an electrical signal, An electroluminescent sheet for irradiating light to a subject in contact with the cover plate while emitting light by an applied power source is disposed on a bottom surface of the cover plate. The method of claim 1, The EL sheet is a low-power optical pointing device, characterized in that disposed along the periphery of the edge excluding the leading region. The method of claim 2, The EL sheet is low power optical pointing device, characterized in that disposed only on a portion around the bottom edge of the cover plate. The method of claim 1, The EL sheet is low power optical pointing device, characterized in that disposed on the side of the cover plate. The method of claim 1, The EL sheet is disposed on the upper surface of the cover plate, the low power optical pointing device, characterized in that arranged around the edge except the leading area portion. delete The method of claim 1, The optical guide means, A first waveguide having an incidence surface for incident light reflected from the subject, a reflection surface for redirecting the incident light at a 45 ° angle, and a convex exit surface for condensing the redirected light; And a second waveguide having a convex incidence surface for incident light emitted from the first waveguide, a reflection surface for redirecting the incident light at an angle of 45 °, and a exit surface for emitting the redirected light. Low power optical pointing device. The method of claim 1, The optical guide means, A reflector for redirecting light reflected from the subject at a 45 ° angle; And a condenser lens for condensing the light redirected by the reflector. The method of claim 1, The optical guide means, A first reflecting mirror which redirects the light reflected from the subject at a 45 ° angle; A condenser lens for condensing light diverted by the first reflecting mirror; And a second reflector for redirecting the light collected by the condenser lens at a 45 ° angle. The method of claim 1, The optical guide means, And a curved reflector having a concave reflecting surface for condensing the light reflected from the subject at a 45 ° angle. The method of claim 1, The optical guide means, A curved reflecting mirror having a concave reflecting surface for condensing light reflected from the subject at a 45 ° angle; And a condenser lens for condensing the light redirected by the curved reflector secondarily. The method of claim 1, The optical guide means, A first curved reflector having a concave reflecting surface for condensing the light reflected from the subject at a 45 ° angle; And a second curved reflector having a concave reflecting surface that redirects the light redirected by the first curved reflector at a 45 [deg.] Angle again. 10. A personal portable terminal comprising the low power optical pointing device of any one of claims 1 to 5.

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