KR100773807B1 - Optical pointing device using diffractive gratings - Google Patents

Abstract

An optical pointing device using diffractive gratings is provided to enable a low-cost production by using a low-priced diffractive grating and a photodiode in place of an expensive optical pointing device. An optical pointing device includes light emitting units(521,522), a reflection film(510), first and second diffractive gratings(501,502), third and fourth diffractive gratings(503,504), light receiving units(531,532,533,534) and a position calculating unit(540). The light emitting units emit light to a first diffractive grating member for controlling a moving pointer. the reflection film reflects the light emitted from the light emitting units. The first to fourth diffractive gratings diffract the light reflected on the reflection film. The light receiving units receive an expanded optical pattern. The position calculating unit measures variations in horizontal and vertical axis directions along the received expansion optical pattern.

Description

Optical pointing device using diffractive gratings}

1 is a reference diagram showing the Korean Patent Publication No. 2004-0089243,

2 is a reference diagram showing the Korean Patent Publication No. 2006-0034735,

3 is a reference diagram showing the Korean Patent Publication No. 2006-0017464,

4 is a reference diagram showing the Korean Patent Publication No. 2006-0027930,

5 is a configuration diagram showing a first embodiment of the optical pointing device according to the present invention;

6 is a configuration diagram showing a second embodiment of the optical pointing device according to the present invention;

7 is a configuration diagram showing a third embodiment of the optical pointing device according to the present invention;

8 is a configuration diagram showing a fourth embodiment of the optical pointing device according to the present invention;

9 is a configuration diagram showing a fifth embodiment of the optical pointing device according to the present invention;

10 is a view showing the micro-rotation of the diffraction grating according to the present invention,

11 is a view showing an embodiment of a position calculating means according to the present invention;

12 is a view showing signals for each step of the position calculating means of FIG. 11;

13 is a view showing an embodiment of a personal portable terminal equipped with an optical pointing device according to the present invention.

                <Explanation of symbols for main parts of the drawings>

501: the first grating 502: the second grating 503: the third grating

504: fourth diffraction grating 510: reflecting films 521, 522: light emitting means

531: first light receiving element 532: second light receiving element 533: third light receiving element

534: fourth light receiving element 540: position calculating means 541: amplifying circuit

542: position calculation circuit 601: fifth lattice 602: sixth lattice

801, 802: reflective mirror 810: optical filter 820: printed circuit board

910: portable terminal 920: pointing device 930: run button

The present invention relates to an optical pointing device using a diffraction grating, and more particularly, to a two-dimensional optical pointing device in a small space such as a personal portable terminal using a diffraction grating without the configuration of a complicated optical system such as a lens module.

Conventional mobile terminals such as mobile phones utilize keypads, menu keys or function keys as an input module method, and support various functions such as phone number input or sentence writing using direction setting keys.

However, in recent years, by being able to express graphics and the like on the display unit of a personal portable terminal, it becomes possible to use the display unit in two dimensions as in a personal computer. Accordingly, a two-dimensional optical pointing device for a portable wireless information terminal having a two-dimensional pointing device for effectively using an application program using a graphic user interface has been developed.

Such a conventional apparatus includes Korean Patent Publication No. 2006-0017464 'Personal Handheld Terminal including Ultra Slim Optical Joystick and Ultra Slim Optical Joystick', Korean Patent Publication No. 2004-0089243 'Small Pointing Device Using Finger Surface', Korean Patent Publication There is a device such as 2006-0034735 'Ultra-slim optical joystick using a micro lens array structure' and Korea Patent Publication No. 2006-0027930 'Ultra-slim optical joystick using an integrated optical waveguide structure'.

1 is a reference diagram showing a Korean Patent Publication No. 2004-0089243 'small pointing device using the finger surface'. Referring to FIG. 1, the image input apparatus used in the conventional optical mouse includes a cover glass 110, a lens 120, a blocking film 130, and an image sensor 140. Light generated from the light emitting diodes 150 is reflected by a finger to obtain fingerprint image information, and the light is condensed on the optical image sensor through the lens 120. The collected information is converted into an electrical signal, and a main body such as a personal portable terminal analyzes the movement of a finger from the electrical signal and detects X and Y displacements. However, the ultra-slim personal portable device should use a lens with a short focal length. In this case, even if the focal length is slightly shifted up and down during assembly, the image change on the surface of the image sensor is larger than the size of the image sensor. do. Therefore, there is a problem that the height of the basic device must be limited due to the optical system depth of focus limitation.

2, 3 and 4 are proposed techniques to overcome the problem that the height of the basic device is limited due to the depth of focus limit of the optical system.

FIG. 2 is a reference diagram showing Korean Laid-Open Patent Publication No. 2006-0034735 “Ultra-slim optical joystick to which a micro lens array structure is applied”. Referring to FIG. 2, in order to overcome the depth of focus limit of the optical system limited by the radius of curvature of the lens, the focal length is reduced by utilizing the array 160 of microlenses having a small radius of curvature. However, this device has the disadvantage of manufacturing a precise micro lens array having a radius of curvature of several tens of micrometers through micro injection molding, ultraviolet curing molding, and hot embossing technique. In order to solve the problem of optical signal crosstalk between image sensors, there is a problem in that the microlens array having a radius of curvature of several tens of micrometers is aligned one-to-one with the number of pixels of the image pickup area of the image sensor.

FIG. 3 is a reference diagram illustrating Korean Laid-Open Patent Publication No. 2006-0017464 'a personal portable terminal including an ultra slim optical joystick and an ultra slim optical joystick'. Referring to FIG. 3, in order to overcome a problem in which a short focal length lens may occur in FIG. 1, the optical path is adjusted in the thickness direction to further increase the optical path. The light generated by the light source 310 is reflected by the finger surface 100, which is the subject, reaches the first funnel lens 330 through the first waveguide 320, and includes a second planar lens 340. The light is collected on the image sensor surface 360 through the second optical waveguide 340. When the change in coordinates is calculated using the change in the captured image, the optical joystick device for moving the pointer on the display such as an LCD may be implemented. However, this device is separated from the first waveguide and the second waveguide so that the image formed in proportion to the degree of mismatch of the optical axis during the assembly process may deviate from the image sensor surface 360, which may cause defects. As the diameter is smaller than 2 mm, there is a problem that the aberration increases and the blurring of the image due to the diffraction effect becomes prominent.

FIG. 4 is a reference diagram showing Korean Patent Publication No. 2006-0027930 'Ultra-slim optical joystick using an integrated optical waveguide structure'. Referring to Figure 4, it is a technique proposed to solve the problems of the prior art as shown in FIG. Light generated by the light source 310 has optical information of the fingerprint on the finger surface 100, enters the first planar lens 330, and then includes the integrated optical waveguide 350 and the second planar lens ( The light is collected on the image sensor surface 360 by passing through the blocking film 370 for removing the light through the 340. Such a structure in which the lens and the optical waveguide are integrated solves the problem of misalignment of the optical axis and can increase the diameter of the lens to prevent image blur due to aberration and diffraction caused by a small lens diameter of less than 2 mm. There is a problem in that an integrated optical waveguide having a precise and complicated shape in which two Plano-Convex lenses and an optical waveguide are integrated is manufactured.

All of the above-described conventional techniques detect the displacement using the movement tracking method of the movement information of the fingerprint as the touch method. These devices are commonly required to have a lens module for transferring a fingerprint or arbitrary pointer-like image to the light receiver, and it is difficult to realize an ultra-slim optical pointing device due to optical limitations in reducing the focal length of the lens module. In addition, since the complicated and precise lens module has to be manufactured, the defect rate is high due to the difficulty of the manufacturing and assembly process.

The fingerprint recognition method is very difficult to detect two-dimensional displacement in some cases when it is used by a person who is unable to collect fingerprints or by a person with sweating on the hands. It also has great vulnerability for use in the rainy season, sauna and swimming pool. Furthermore, if a fluid containing chemicals is left from the finger of a particular user, the next fingerprint is frequently seen as a residual fingerprint problem where two fingerprints overlap when the next user enters a finger fingerprint. Will interfere.

Even if a pointer having an arbitrary shape is used without using a fingerprint, it is inconvenient to carry an additional mechanism having a pointer shape together with the personal portable device, and the pointer shape, its moving part and the supporting part are mounted in the ultra-slim device. The difficulties that must be followed. In addition, these conventional technologies have the disadvantage of having a relatively high resolution fingerprint scanner chip or CCD fabricated in a CMOS process, and a separate image processing algorithm for tracking the movement of a fingerprint or a pointer must be implemented and requires a complicated image processing operation. There is a disadvantage.

Accordingly, an object of the present invention is to provide a two-dimensional optical pointing device using a diffraction grating for inputting information in a small space such as a personal portable terminal without configuring an optical system such as a lens module.

The object of the present invention is a light emitting unit for emitting light; A reflecting film for reflecting light emitted from the light emitting unit; A first diffraction portion for diffracting the light reflected from the reflective film; A lattice support for sliding movement of the first diffractive portion; A second diffraction portion disposed to be spaced apart from the first diffraction portion by a predetermined distance, and configured to transmit light diffracted by the first diffraction portion to form an enlarged optical pattern; A light receiving unit for receiving the enlarged light pattern; And a position calculation unit for measuring displacements in the horizontal and vertical directions in accordance with the enlarged light pattern received by the diffraction grating.

Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5 is a block diagram showing a first embodiment of the optical pointing device according to the present invention, the optical pointing device using a horizontal or vertical diffraction grating device according to the first embodiment of the present invention is separated from the X-axis, Y-axis The used diffraction gratings 501, 502, 503, 504 are used.

Here, the two-dimensional optical pointing device is applied to the first and second gratings 501 and 502 and the reflective film 510 having a predetermined pitch in the vertical direction to the light emitting means 521, 522, the reflective film 510, and the reflective film 510. The third and fourth diffraction gratings 503 and 504 having a predetermined pitch in the horizontal direction, the light receiving units 531, 532, 533 and 534, and the position calculating means 540 are included.

On the other hand, the third and fourth gratings 503 and 504 are arranged at pitches having the same or smaller difference as the first and second gratings 501 and 502 of predetermined pitches, respectively. At least one third and fourth grids 503 and 504 rotated slightly compared to 501 and 502. In addition, the pitch of each of the first to fourth gratings 501, 502, 503, and 504 may be configured differently.

The light emitting means 521, 522 emits light to the first diffraction grating parts 501, 503, and 510 for controlling the moved pointer. The light emitting means 521 and 522 may be a light emitting diode (LED) or a laser diode (LD).

The first diffraction grating portions 501, 503, and 510 are movable by means 100 capable of applying a force such as a finger, and the light generated from the light emitting means 521 and 522 is reflected through the reflective film 510. Reflected and diffracted through the first and third gratings 501 and 503. The first diffraction grating portions 501, 503, and 510 have a lattice support (not shown) for enabling the sliding of the first and third diffraction gratings 501 and 503. ) Two-dimensional movement on the (Y) axis.

The image generated by the light reflected and diffracted by the first diffraction grating portions 501, 503, and 510 passes through the second and fourth diffraction gratings 502 and 504, and thus the first to fourth diffraction gratings 501, 502, and 503. , To form an optical pattern that is enlarged beyond the pitch period of 504. Here, the enlarged light pattern is determined according to the pitch difference between the first diffraction grating 501 and the second diffraction grating 502 or the degree of rotation of the second diffraction grating 502 relative to the first diffraction grating 501. Also, the pitch difference between the third grating 503 and the fourth grating 504 or the degree of rotation of the fourth grating 504 relative to the third grating 503 is determined.

Here, the first diffraction grating 501 or the third diffraction grating 503 has two diffraction patterns in the X-axis direction or the Y-axis direction different positions within the first grating 501 or the third grating 503. The two diffraction patterns in the X-axis direction or the Y-axis direction may be arranged in a cross shape that overlaps each other. Of course, the first and third gratings 501 and 503 configured as described above may include grating supports for enabling sliding.

The light receiving units 531, 532, 533, and 534 are enlarged using the first and second light receiving elements 531 and 532 for measuring the X-axis displacement and the third and fourth light receiving elements 533 and 534 for the Y-axis displacement measurement. The energy of the light pattern is obtained. Here, the photodiode is preferably a photodiode.

The position calculating means 540 compares the amplification circuit 541 for amplifying the signals acquired by the light receiving units 531, 532, 533, and 534, and digitizes the amplified signal to a desired voltage by dividing the amplified signal into more than and less than a desired light intensity. And a position calculating circuit 542 for detecting a moving distance and a direction with respect to each direction of the X-axis and Y-axis.

For example, the light emitted from the light emitting means 521, 522 is transmitted to the first diffraction grating parts 501, 503, 510 which are moved by the finger 100, and the like, and the transmitted light is the first diffraction grating part 501. Reflected by the reflective film 510 of the 503 and 510, and the reflected light is diffracted by the first and third gratings 501 and 503. This diffracted image is transmitted through the second and fourth diffraction gratings 502 and 504 to generate an enlarged optical pattern. The energy of this light pattern is obtained by the first and second photodiodes 531 and 532 for the X-axis displacement measurement and the third and fourth photodiodes 533 and 534 for the Y-axis displacement measurement. The acquired signal is amplified and subjected to a comparator circuit which digitizes to a desired voltage by dividing it into more than or less than the desired light intensity, and then, through the position calculating circuit 542, in the moving distance and direction with respect to each of the X and Y axes. Is detected. This distance and direction information has displacement information similar to that of an optical mouse moving on a flat floor surface. Using this result, the pointer, which is an indicator that moves on a display device screen of a personal mobile terminal such as a mobile phone or a PDA, can be moved. do.

6 is a configuration diagram showing a second embodiment of the optical pointing device according to the present invention. The optical pointing device using the cross-shaped diffraction grating according to the second embodiment of the present invention is a fifth diffraction grating 601 which is a cross-shaped diffraction grating. And a sixth lattice 602.

Here, the fifth diffraction grating 601 and the sixth diffraction grating 602 are cross-shaped diffraction gratings for diffracting incident light in the horizontal and vertical directions, respectively. It may be a grating, and may also be a cross diffraction grating in which a horizontal diffraction grating having a predetermined pitch in a horizontal direction and a vertical diffraction grating having a predetermined pitch in a vertical direction are superimposed on each other.

In this case, the sixth diffraction grating 602 is arranged at a pitch having the same or smaller difference as the fifth diffraction grating 601 having a predetermined pitch, and at least one or more rotated slightly compared to the fifth diffraction grating 601. The sixth lattice 602.

Light generated from one light emitting means 521 is emitted to the second diffraction grating portions 510 and 601 of the cross shape which is moved by the finger 100 or the like and is reflected by the reflective film 510 and reflected by the reflective film 510. The cross-shaped sixth image in which the generated light is diffracted by the fifth diffraction grating 601 has the same pitch as the fifth diffraction grating 601 but is slightly rotated with respect to the fifth diffraction grating 601. The diffraction grating 602 is transmitted to generate an optical pattern. Here, the enlarged light pattern is determined according to the pitch difference between the fifth diffraction grating 601 and the sixth diffraction grating 602 or the degree of rotation of the sixth grating 602 with respect to the fifth diffraction grating 601. .

The energy of the optical pattern is obtained by the first and second photodiodes 531 and 532 for measuring the X-axis displacement, and the third and fourth photodiodes 533 and 534 for the Y-axis displacement measurement. The acquired signal is represented as a signal separated in the movement amount and direction of the X and Y axes, and each signal is amplified and digitized through a comparator circuit, and the digitized signal is passed through the position calculation circuit 542 to each of the X and Y axes. It is detected by the distance and the direction of movement.

7 is a configuration diagram showing a third embodiment of the optical pointing device according to the present invention. The optical pointing device according to the third embodiment of the present invention is a fifth diffraction grating 601 which is a cross-shaped diffraction grating of FIG. A second diffraction grating 502, which is a vertical diffraction grating of 5, and a fourth grating 504, which is a horizontal diffraction grating, are used.

The light reflected by the reflective film 510 is diffracted by the fifth diffraction grating 601 to transmit the second and fourth diffraction gratings 502 and 504 to generate an optical pattern. The generated light pattern is separately enlarged and displayed on the X and Y axes. Here, the enlarged optical pattern is the difference in pitch between the diffraction grating and the second diffraction grating 502 having the pitch in the longitudinal direction of the fifth diffraction grating 601 and the transverse direction of the fifth diffraction grating 601. It is determined according to the pitch difference between the diffraction grating having a pitch and the fourth diffraction grating 504, or the degree of rotation of the second diffraction grating 502 and the fourth diffraction grating 504 with respect to the fifth diffraction grating 601 It depends on.

8 is a block diagram showing a fourth embodiment of the optical pointing device according to the present invention. In the optical pointing device according to the fourth embodiment of the present invention, the light emitting means 521 and 522 have a circuit in the optical pointing device of FIG. When it is vertically fixed to the substrate 820, reflecting mirrors 801, 802 for reflecting the light emitted from the light emitting means (521, 522) to proceed to the first diffraction grating portion (501, 503, 510) Include.

At this time, in order to remove noise due to ambient light and to detect only a waveform having a desired shape, an optical filter 810 is installed to remove noise that may be generated by the light receiving units 531, 532, 533, and 534.

On the other hand, the circuit board 820 is mounted to the light emitting means (521, 522) and the light receiving unit (531, 532, 533, 534) as a flexible circuit board.

9 is a block diagram showing a fifth embodiment of the optical pointing device according to the present invention. In the optical pointing device according to the fifth embodiment of the present invention, the light emitting means 521 of the optical pointing device of FIG. When it is fixed vertically to 820, it includes a reflecting mirror 801 for reflecting the light emitted from the light emitting means 521 to proceed to the fifth diffraction grating 601.

At this time, the light transmitted through the sixth diffraction grating 602 is enlarged at the same time the X-axis and Y-axis. The two-dimensional optical pointing device using a cross-shaped diffraction grating is an optical filter X (not shown) that separates the light pattern into light magnified in the X-axis direction and light magnified in the Y-axis direction to detect the light pattern in a desired direction. It may include an optical filter Y (not shown) for separating. In addition, the light receiving units 531, 532, 533, and 534 may include an optical filter 810 for removing noise due to ambient light.

10 is a view showing the micro-rotation of the diffraction grating according to the present invention. Referring to FIG. 10, the lower diffraction gratings 502, 504, and 602 positioned on the light receiving units 531, 532, 533, and 534 with respect to the upper diffraction gratings 501, 503, and 601 located on the finger 100 side. Is rotated at a small angle θ, when the upper and lower diffraction gratings are disposed to overlap each other at a predetermined distance from each other, the light reflected by the reflective film 510 passes through the lower diffraction grating, and thus a large period pattern appears. have.

In this case, the period λ _m of the newly formed enlarged pattern is represented by Equation 1 below. Where P is a pitch and? Represents a rotation angle.

Accordingly, the photodiodes of the light receiving units 531, 532, 533, and 534 for detecting the amounts of movement of the X and Y axes are positioned at a distance of λ _m / 4 from each other on the same axis, thereby detecting the movement direction and displacement. have. At this time, the movement of one pitch P in the X-axis and Y-axis directions is represented by the movement of the enlarged pattern period λ _m .

For example, the light passing through the upper and lower diffraction gratings having a pitch P of 0.1 mm in the X-axis direction has a pattern period λ _{m that} is enlarged according to the small rotation angle θ, which is about 1 mm in the X-axis direction. During the movement of 10P, the enlarged pattern moves by 10λ _m , and the light receiving unit detects the movement of the enlarged pattern as an analog signal. Therefore, by properly adjusting the pitch of the diffraction grating, the distance between the diffraction gratings, the rotation angle and the size of the light receiving portion, it is possible to easily measure the movement direction and displacement of the diffraction grating.

11 is a view showing an embodiment of the position calculation means according to the present invention, Figure 12 is a view showing a signal for each step of the position calculation means of FIG. 11 and 12, the position calculating means 540 processes signals acquired through the light receiving units 531, 532, 533, and 534.

The distance between the first and second photodiodes 531 and 532 for detecting the movement amount and direction of the X axis and the distance between the third and the fourth photodiodes 533 and 534 for detecting the movement amount and direction of the Y axis are λ _m / It is preferable that the distance is an integer multiple of four. On the other hand, the period of expansion according to the pitch period of each of the upper and lower grating may be different.

)와 미소한 위상 차이를 가지는 펄스신호(△A, △

)로 변환되고, 신호 B는 그 반전 신호(

)로 변환된다. 이 신호들은 각각 +방향의 신호를 검출해 내는

×△A, 및 -방향의 신호를 검출해 내는

×△

의 논리회로를 거쳐 X축, Y축 각 방향에 대하여 이동거리과 방향을 검출한다.The signal A detected by the first and second photodiodes 531 and 532 and the detected signal B by the third and fourth photodiodes 533 and 534 pass through the amplification circuit 541 and have a difference between a maximum voltage and a minimum voltage of 1 Volt or more. Amplified into an analog signal with The amplified analog signal is converted into a step signal divided into a case where the desired intensity is above and below the desired light intensity and divided by the desired maximum voltage and the minimum voltage. The signal A is its inverted signal (

) And a pulse signal having a small phase difference (ΔA, △

) And signal B is its inverted signal (

Is converted to). Each of these signals detects signals in the + direction.

To detect signals in the ΔΔ and − directions

× △

The moving distance and direction are detected for each of the X and Y axes through the logic circuit.

13 is a view showing an embodiment of a personal portable terminal equipped with an optical pointing device according to the present invention. Referring to FIG. 13, the personal mobile terminal 910 such as a mobile phone includes the optical pointing device 920 of the present invention. The optical pointing device 920 moves the pointer to the position to be controlled by moving the upper diffraction gratings 501, 503, and 601 by means of applying a finger or a finger-like force. In addition, the personal mobile terminal 910 preferably includes at least one or more execution buttons 930 connected to the optical pointing device 920. The execution button 930 may be used to input an execution command by selecting a target using a pointer moved by the optical pointing device 920.

On the other hand, the diffraction grating is produced by printing a diffraction pattern having a periodic pitch on a transparent plastic film or glass. In addition, it can be produced by etching the silicon wafer.

Although the present invention has been shown and described with reference to the preferred embodiments as described above, it is not limited to the above embodiments and those skilled in the art without departing from the spirit of the present invention. Various modifications and variations are possible without departing from the spirit of the present invention and equivalents of the claims to be described below.

Therefore, the optical pointing device using the diffraction grating of the present invention has an advantage that a small optical pointing device can be realized without the use of complicated optical systems such as a complicated lens and an optical waveguide by using the diffraction grating.

In addition, the present invention has the advantage that low-cost production is possible by using a low-cost diffraction grating and a photodiode instead of an expensive optical pointing device using a conventional fingerprint motion tracking method.

Claims (13)

A light emitting unit for emitting light; A reflecting film for reflecting light emitted from the light emitting unit; A first diffraction portion for diffracting the light reflected from the reflective film; A lattice support for sliding movement of the first diffractive portion; A second diffraction portion disposed to be spaced apart from the first diffraction portion by a predetermined distance, and configured to transmit light diffracted by the first diffraction portion to form an enlarged optical pattern; A light receiving unit for receiving the enlarged light pattern; And Position calculation unit for measuring the amount of displacement in the horizontal axis and vertical axis direction according to the enlarged light pattern received Optical pointing device using a diffraction grating comprising a. The method of claim 1, The first and second diffractive portions, Horizontal diffraction grating; And Vertical diffraction grating Optical pointing device using a diffraction grating comprising a. The method of claim 1, The first and second diffractive portions, Cross diffraction grating for diffracting incident light in horizontal and vertical directions Optical pointing device using a diffraction grating comprising a. The method of claim 3, wherein The cross-shaped diffraction grating is an optical pointing device using a diffraction grating is a high overlap between the horizontal diffraction grating and the vertical diffraction grating. The method of claim 1, The first diffractive portion, A cross diffraction grating combining a horizontal diffraction grating having a predetermined pitch in a horizontal direction and a vertical diffraction grating having a predetermined pitch in a vertical direction, The second diffractive portion, A horizontal diffraction grating having a predetermined pitch in the horizontal direction; And Longitudinal diffraction grating with a predetermined pitch in the longitudinal direction Optical pointing device using a diffraction grating comprising a. The method of claim 2, A plurality of reflection mirrors for reflecting light from the light emitting portion to the first diffractive portion Optical pointing device using a diffraction grating further comprising. The method of claim 3, wherein At least one reflecting mirror for reflecting light from the light emitting portion to the first diffractive portion; And Located between the second diffractive portion and the light receiving portion, the first optical filter unit for separating the enlarged optical pattern in the horizontal and vertical direction Optical pointing device using a diffraction grating further comprising. The method of claim 5, At least one reflecting mirror for reflecting light from the light emitting portion to the first diffractive portion Optical pointing device using a diffraction grating further comprising. The method of claim 1, The light receiving unit, A first photodiode unit having at least two photodiodes for receiving the enlarged optical pattern in a horizontal axis direction; And A second photodiode portion having at least two photodiodes for receiving the enlarged optical pattern in a vertical axis direction Optical pointing device using a diffraction grating comprising a. The method of claim 9, And an interval between photodiodes of the first photodiode portion and photodiodes of the second photodiode portion is an integer multiple of one quarter of the enlarged light pattern period. The method of claim 10, A second optical filter unit for removing ambient light entering the light receiving unit Optical pointing device using a diffraction grating further comprising. The method according to any one of claims 1 to 11, The second diffractive portion is an optical pointing device using a diffraction grating is disposed off the axis parallel to the axis on which the first diffractive portion is disposed. The method according to any one of claims 1 to 11, And a diffraction grating having a pitch different from that of the first diffraction portion and that of the second diffraction portion.

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