WO2003060684A1

WO2003060684A1 - Digital pen device

Info

Publication number: WO2003060684A1
Application number: PCT/KR2003/000081
Authority: WO
Inventors: Yong-Ho Jo
Original assignee: Yong-Ho Jo
Priority date: 2002-01-16
Filing date: 2003-01-15
Publication date: 2003-07-24
Also published as: AU2003235640A1; KR20030062032A

Abstract

The present invention relates to a digital pen device capable of inputting a certain character or image into an information device such as PC, PDA, etc. using an optical mouse semiconductor chip which is adapted to convert a movement of a mouse into a change value of a cursor on a monitor using an image sensor. The digital pen device includes an optical unit which includes a lens in which a depth of a focus is larger than a first critical value, and a diameter of the same is smaller than a second critical value, and a light emitting diode(LED) which is capable of scanning a certain range recognizable by the lens, an optical mouse semiconductor chip.

Description

DIGITAL PEN DEVICE

TECHNICAL FIELD

The present invention relates to a digital pen device capable of

obtaining a function of a computer mouse and inputting a certain character

and image in an information device such as a mouse, computer, PDA, etc.,

and in particular to a digital pen device which is capable of making an

image sensor of an optical mouse semiconductor chip sense pad having a

lattice pattern formed of a dot or line on a white background using a lens

which has a long focus, small diameter and deep focusing depth, so that it

is possible to display a value corresponding to a movement of a coordinate

even when a digital pen is distanced from a pad by a certain height.

BACKGROUND ART

Figure 1 is a view illustrating an example of an operation for writing a

Korean character of "°] " using a digital pen. When writing " o ", the writing

operation is classified into an operation 11 in which a pen contacts with a

surface of a writing medium and writes a character, an operation 22 in

which the pen is lifted from the surface and is moved to a position to write

the next character of " l ", and an operation 33 in which the pen contacts

with the surface and writes the character " l ".

When the pen is lifted up and is moved to a certain position to write

the next character, the distance between the pen and the surface is generally within 1 mm when writing characters on a paper. If the size of the

character is large, the above distance is slightly increased. When writing

the characters in one line, the line is changed, and the characters are

written, the pen is distanced from the surface by about 5mm in the case

that the characters are written on a A4 paper. The above described

operation may be different based on a writer's writing habit. When drawing

a certain image on paper, the pen is distanced higher than when the

characters are written.

Therefore, in order to constitute a digital pen using a semiconductor

chip adapted for an optical mouse, a movement of coordinate must be

properly implemented when the pen is distanced from the surface even

when the distance from the lens to an object is minimum 5mm compared

to when the pen contacts with the surface.

In the case that a Korean character "°1" is written using a mouse, a

left button of the mouse is clicked and draws a character " o " in a circle

movement, and the left button of the mouse is released, and then the

mouse is moved to a position for writing the next character of " 1 ".

Thereafter, the left button of the mouse is clicked, and the character " 1 " is

written. Namely, the writing operation needs many steps, and a much skill

is needed.

In addition, the exercise is performed by grabbing the mouse using a

palm and using the movement of arm, it is not considered as an accurate operation for writing the characters or drawing the image. Therefore, in

order to implement an accurate character and image using a common

computer mouse, much skill is needed. Even when the user has a skilled

art, it is impossible to implement the same characteristics as his/her own

writing and drawing skills.

In order to improve the above problems, a pen type mouse is

developed for performing an accurate cursor control for an accurate

graphic work or signing operation. As an example, there is Korean Utility

model No. 196758 "Pen mouse device using CMOS sensor. The pen

mouse device using the CMOS sensor is not implemented at a low angle

lighting. Therefore, the movement of the pen mouse device is not detected

on the surface in which there is not a certain element such as a pattern,

etc. in which the CMOS sensor recognizes a value of movement of the

image. In this case, the operation is not uniform based on the state of the

surface.

In addition, in the above device, in order to write a certain character or

draw an image, when the pen mouse device is distanced from the surface

by more than a certain distance, there is not disclosed a certain condition

for detecting the movement of the coordinate. Therefore, it is impossible to

write characters or draw images.

In another conventional art, there is provided Korean Patent

application No. 10-2000-0077162 Optical mouse device". In the above optical mouse device, it is possible to normally operate the optical mouse

device on all types of surfaces without an additional mouse pad by

transferring light incident from a lighting device 101 through an optical

guide 102 to the surface 100 at a lower angle. In addition, the way of the

reflecting light which is converged through an optical way changing unit

103b is changed vertically, so that the image sensor 104 is installed in an

inner side surface of the body of the optical mouse device. Therefore, in

the above device, the thickness of a writing portion of the optical mouse

device may be decreased.

In addition, in the optical mouse device, the light from the LED like an

optical mouse which uses a semiconductor chip for an optical mouse is

converged and is made to a certain parallel light for thereby lighting the

surface at a lower angle, so that it is possible to recognize a shadow which

is formed by a small protrusion on the surface using an image sensor, so

that a movement of a pen mouse device is changed to a moved value of

the coordinate.

However, the common optical mouse which is widely used operates

with a good performance on an office white paper which has small

protrusions based on a low angle lighting, namely operates better for

almost surfaces, however in the case of a common office white paper,

when the common optical mouse is lifted by 1 mm, it does not work.

Figure 4 is a view illustrating an operation characteristic of a certain product of the conventional optical mouse. Figure 4 is a graph of an

average error ratio based on a distance change between the surface and

the optical mouse based on the kinds of the surfaces. As shown in Figure

4, in the case that the surface is an office white paper, if the optical mouse

is lifted by more than 0.2mm from the distance of 2.4 which is an optimum

distance from the lens of the optical mouse to the surface, the error ratio is

sharply increased.

The distance that the pen is lifted and moved to a certain position for

writing the next character is within 1 mm when writing on a common paper.

If the size of the character is increased, the distance is increased.

When writing another line after writing one line by changing the line, in

the case of a A4 paper, the distance between the pen and the surface is

about 5mm. The above operation may be different from a user's habit.

When drawing an image, the distance is more increased compared to

when writing characters.

Therefore, in order to constitute the digital pen using a semiconductor

chip for an optical mouse, when the distance from the pen to an object is

minimum 5mm compared to when the pen contacts with the surface, the

movement of the coordinate should be freely performed.

Therefore, the optical mouse device has a characteristic in which the

optical mouse operates better with respect to almost kinds of the surfaces

including a characteristic that the optical mouse device operates at high performance on an office white paper like a common optical mouse.

However, the conventional optical mouse is not capable of sensing the

distance of the coordinate based on a change of the distance. Therefore,

the conventional optical mouse is not used as a digital pen.

In addition, the conventional optical mouse device has a problem that

when the pen is distanced from the surface like the optical mouse, the

lighting is out of a range that the lens senses.

Figure 3 is a view illustrating a conventional optical mouse device and

a lighting device which is used in a conventional optical mouse that uses a

semiconductor chip for an optical mouse. Figure 3 illustrates the first

surface 1 when the pen contacts with the surface, the second surface 2

when the pen is dropped on the surface, a lens 3 for imaging an image of

the surface on a sensor, a way 4 of a light source for lighting, a light way 5

in which an image of the surface is imaged, and a recognition range 6 that

the lens recognizes.

Figure 3 is a view illustrating an example that the light 4 of the LED is

outputted in parallel at an angle of 20° with respect to the first surface 1

and the second surface 2. In the case of a product of the semiconductor

which is used for a common optical mouse, the size of the built-in CMOS

sensor is 1 mm in all directions. In the case of the 1 :1 optical system(the

distance from the lens to the sensor and the distance from the lens to the

object are same, so that the size of the object is the same as the size of an image), the recognizable range 6 is 1 mm. Namely, the distance

difference between the first surface 1 and the second surface 2 is 5mm.

As shown in Figure 3, the light of the LED which lights a recognizing

range of the first surface 1 is distanced from the second surface 2 when

the pen is distanced from the surface by 5mm, and the light of the LED

becomes away from the recognizing range. In this case, in order to light

the recognizing ranges of the first surface and the second surface, the

light from the optical guide must be spread at more than 20°, not in a

parallel light.

As shown in Figure 3, when spreading the light at more than 20°, not

in a parallel light, the light outputted to the second surface and the angle of

the surface are 54°, so that the effect of the lower angle lighting is not

implemented. In addition, in the case that the light is scanned based on a

parallel light which has a wider width than the light shown in the drawing,

the thickness of the pen is disadvantageously increased.

Therefore, in the optical mouse device and conventional optical

mouse, when the distance between the lens and object is out of the

optimum value, it is impossible to detect the movement of the coordinate.

DISCLOSURE OF INVENTION

Accordingly, it is an object of the present invention to provide a digital

pen device which overcomes the problems encountered in the conventional art.

It is another object of the present invention to provide a digital pen

device which is capable of providing a certain shaped lattice pattern

formed of a certain line or dot of a color which does not reflect a light of a

LED on a surface having a random reflection surface and including a pad

in which more than one lines of different lattice patterns are imaged in an

image sensor, so that even when a distance between a digital pen and a

surface is changed, a movement of a coordinate is properly implemented,

whereby an information is inputted into various information devices like a

certain character is written or an image is drawn using a common pen.

It is another object of the present invention to provide a digital pen

device which is capable of providing a certain shaped lattice pattern

formed of a certain line or dot of an opacity color in a surface having a

LED surface and includes a pad that more than one lines of different

direction lattice patterns in an image sensor, so that even when a distance

between a digital pen and a surface is changed, a movement of a

coordinate is properly implemented, whereby an information is inputted

into various information devices like a certain character is written or an

image is drawn using a common pen.

In order to achieve the above objects, in a digital pen device having a

digital pen body, an optical unit, an optical mouse semiconductor chip, and

a transmission unit, there is provided a digital pen device which includes an optical unit which includes a lens in which a depth of a focus is larger

than a first critical value, and a diameter of the same is smaller than a

second critical value, and a light emitting diode(LED) which is capable of

scanning a certain range recognizable by the lens, an optical mouse

semiconductor chip in which an image sensor adapted to detect a light

from the optical unit and converts the light into an electrical signal and a

digital signal processing unit adapted to compute and process a

coordinate value of a cursor displayed on a computer monitor using an

electrical signal converted by the image sensor are integrated into one

semiconductor chip, a transmission unit which is adapted to transmit a

coordinate value computed by the optical mouse semiconductor chip to a

computer body, and a pad which includes a certain lattice pattern formed

of lines or dots of a color which does not reflect a light of the light emitting

diode in a surface having a random reflection surface, so that more than

one line among the lines of different direction lattice patterns is imaged in

the image sensor.

In addition, in the present invention, the dot or line has a color which

is complementary to the color of the light emitting diode.

The member having a random reflection surface is paper.

In order to achieve the above objects, in a digital pen device which

includes a digital pen body, an optical unit, an optical mouse

semiconductor chip, and a transmission unit, there is provided a digital pen device which includes an optical unit which includes a lens in which a

depth of a focus is larger than a first critical value, and the diameter of the

same is smaller than a second critical value, an optical mouse

semiconductor chip in which an image sensor which detects a light from

the optical unit and converts the light into an electrical signal and a digital

signal processing unit which computes and processes a coordinate value

of a cursor which is displayed on a computer monitor using an electrical

signal converted by the optical unit, a transmission unit which transmits a

coordinate value computed by the optical mouse semiconductor chip to a

computer body, and a pad which includes a certain lattice pattern formed

of lines or dots of an opaque color on a surface having a light emitting

surface, so that more than one line among the lines of different direction

lattice patterns are imaged in the image sensor.

In addition, the light emitting surface includes a pad formed of a back

light component of a LCD monitor.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become better understood with reference to

the accompanying drawings which are given only by way of illustration and

thus are not limitative of the present invention, wherein;

Figure 1 is a view illustrating an example for writing a Korean

character of "°l " using a digital pen; Figure 2 is a view illustrating a problem of a lighting device of a

conventional optical mouse;

Figure 3 is a view illustrating an inner construction of a conventional

optical mouse device;

Figure 4 is a view illustrating a graph of an operation characteristic of

a conventional optical mouse used on a certain surface;

Figure 5 is a view illustrating the construction of a digital pen device

according to the present invention;

Figures 6A through 6C are views for describing a change of an image

when an image formed at a low angle lighting on an office empty paper is

imaged in an image sensor according to the present invention;

Figures 7A through 7C are views for describing a change of an image

when a pad formed in a black lattice on a white background is imaged in

an image sensor according to the present invention; and

Figures 8A and 8B are views for describing a change of an actual

image imaged in an image sensor of a semiconductor used in an optical

mouse when an image is lighted at a lower angle on an office white paper.

* Description of major elements of the drawings ^*

500: surface 501 : imaging lens

503: lighting unit 505: hollow pipe

507: optical mouse semiconductor chip 509: transmission unit 600: body

BEST MODE FOR CARRYING OUT THE INVENTION

The preferred embodiments of the present invention will be described

with reference to the accompanying drawings.

Figure 5 is a view illustrating the construction of a digital pen device

according to the present invention. As shown therein, the digital pen

apparatus includes a body, a lens, a LED(light emitting diode), a hollow

pipe, a semiconductor chip for an optical mouse, a transmission unit and a

pad.

The body 600 has a certain shape such as a circular shape or semi¬

circular shape, so that a user easily grabs it. In the lens 501 , a depth of a

focus is larger than a first critical value, and a diameter of the same is

smaller than a second critical value. Here, the first critical value and

second critical value may be determined based on an experiment. The first

critical value represents a value of a depth of a focus that even when a

digital pen is distanced from a pad more than 5mm compared to when the

pen contacts with a surface, the pen contacts with a surface and a moving

speed of a coordinate is not changed.

When a user writes a certain character using a digital pen device or

draws an image, the LED 503 outputs light at a certain angle by which

even when the pen is distanced from the surface by mote than 5mm, a recognizing portion that the lens 501 reads the image is all scanned.

Therefore, even when the distance from the lens to the object is distanced

by more than minimum 5mm compared to when the pen contacts with the

surface, it is possible to trace the movement of the coordinate by detecting

the change of the image. The hollow pipe 505 connects the LED 503 and

the semiconductor chip 507 for the optical mouse.

The optical mouse semiconductor chip 507 is constituted in such a

manner that a digital signal processor(not shown) which is capable of

computing and processing the coordinate values of the cursor displayed

on a computer monitor using an electrical signal converted by an image

sensor(not shown) adapted to detect the light from the LED 503 and to

convert the same into an electrical signal is integrated into one

semiconductor chip. The optical mouse semiconductor chip 507 may be

separately formed of the image sensor(not shown) and the digital signal

processing unit(not shown). In addition, the microprocessor may be used

instead of the digital signal processor(not shown).

The transmission unit 509 is adapted to transmit the coordinate value

computed by the optical mouse semiconductor chip 507 to the computer

body.

The pad 500 includes a certain lattice pattern formed of a certain line

or dot of a certain color which does not reflect the light of the LED on the

surface having a random reflection surface, so that more than one line among the lines of different direction lattice pattern is imaged in the image

sensor. The pad 500 is operable even when a common optical mouse is

distanced from the surface having a high contrast by a few mm. At this

time, the distance of the normal operation may be different based on the

shape of the surface used. Here, it is most preferred to use the lattice

pattern formed in such a manner that the black lines are crossed in a white

paper which has the best performance. The lattice pattern(not shown) is

designed in such a manner that the same has a certain line thickness and

distance so that more than one among two axis having different directions

are imaged in the image sensor. In addition, the pad formed of black dots

in a white background may be used except for the pad formed of a black

lattice in a white background. In addition, the pad may include a lattice or

dot formed of a black color as well as a complementary color of the LED

light.

In addition, in another embodiment of the present invention, the digital

pen device may be formed of a body, a lens, a hollow pipe, an optical

mouse semiconductor chip, a transmission unit, and a pad which emits

light by itself.

As shown in Figure 3, the body, lens, hollow pipe, optical mouse

semiconductor chip and transmission unit are the same as the earlier

embodiment of the present invention. However, the pad(not shown) which

emits light by itself includes a lattice or dot in which opaque lines which do not transmit the light such as a black line on the surface formed of a light

emitting plane like a back light used in the LCD monitor are crossed each

other.

The pad(not shown) which emits light by itself may implement an

operation of the digital pen device without a lighting unit such as LED.

Figures 6A, 6B, 6C, 7A, 7B, 7C, 8A and 8B are views of images

imaged in the sensor when a defocus phenomenon occurs. Figures 6A,

6B and 6C are views illustrating a principle of a change of an image

imaged in a sensor when a small image formed based on a lower angle

lighting on an office white paper has a defocus phenomenon as the

distance from the lens to the object is increased. Figures 7A, 7B and 7C

are views for describing a principle of an image imaged on a sensor when

an image formed in a black lattice in a white background has a defocus

phenomenon as the distance from the lens to the object is increased.

Figures 6A, 7A and 8A are views illustrating a state that when the

position of the surface is in an optimum distance. Figures 7A, 7B and 7C

are views illustrating a state that when the position of the surface is

distanced from the optimum distance. Figures 6C and 7C are views

illustrating a state that the position of the same is distanced more far from

the distance of Figures 6B and 7B.

The contrast(comparison of brightness) between cells of the image

imaged in the sensor must exceeds a certain sensitivity sensible by the sensor in order for the image sensor to detect the movement of the image.

Figures 7A is a view illustrating a state that even when a defocus

occurs due to a change of the distance, the sensor has a condition for

recognizing the image because there is a distinct classification between

the cells. Figures 6A and 6B are views illustrating a state that the

comparison of the brightness between cells is sharply decreased when the

image is defocused in Figure 6.

As described above, the digital pen device according to the present

invention has the following advantages.

First, even when a distance between a digital pen and a surface is

changed, the movement of a coordinate is properly implemented.

Therefore, a certain character and image may be easily inputted into

various information devices like using a pen. As a surface in which the

movement of a coordinate is easily recognized based on the change of the

distance, a paper and a certain surface of a notebook computer except for

the pad may be used. Since there is not a certain lighting device except for

the LED, it is possible to decrease the diameter.

Second, in the case that a pad including a lattice, in which opaque

lines such as a black line through which a light is not transmitted are

crossed, or dot is used on a surface formed of a plane surface which emits

light like a back light used in a LCD monitor, it operates without an

additional lighting device such as LED, so that it is possible to decrease the power consumption of the pen and to decrease the size of the pen.

As the present invention may be embodied in several forms without

departing from the spirit or essential characteristics thereof, it should also

be understood that the above-described examples are not limited by any

of the details of the foregoing description, unless otherwise specified, but

rather should be construed broadly within its spirit and scope as defined in

the appended claims, and therefore all changes and modifications that fall

within the meets and bounds of the claims, or equivalences of such meets

and bounds are therefore intended to be embraced by the appended

claims.

Claims

What is claimed is:

1. In a digital pen device having a digital pen body, an optical unit, an

optical mouse semiconductor chip, and a transmission unit, a digital pen

device, comprising:

an optical unit which includes a lens in which a depth of a focus is

larger than a first critical value, and a diameter of the same is smaller than

a second critical value, and a light emitting diode(LED) which is capable of

scanning a certain range recognizable by the lens;

an optical mouse semiconductor chip in which an image sensor

adapted to detect a light from the optical unit and converts the light into an

electrical signal and a digital signal processing unit adapted to compute

and process a coordinate value of a cursor displayed on a computer

monitor using an electrical signal converted by the image sensor are

integrated into one semiconductor chip;

a transmission unit which is adapted to transmit a coordinate value

computed by the optical mouse semiconductor chip to a computer body;

and

a pad which includes a certain lattice pattern formed of lines or

dots of a color which does not reflect a light of the light emitting diode in a

surface having a random reflection surface, so that more than one line

among the lines of different direction lattice patterns is imaged in the

image sensor.

2. The device of claim 1 , wherein said pad is formed of certain dots

or lines in which more than one image are imaged in the image sensor.

3. The device of either claim 1 or 2, wherein said dot or line has a

color which is complementary to the color of the light emitting diode.

4. In a digital pen device which includes a digital pen body, an optical

unit, an optical mouse semiconductor chip, and a transmission unit, a

digital pen device, comprising:

an optical unit which includes a lens in which a depth of a focus is

larger than a first critical value, and the diameter of the same is smaller

than a second critical value;

an optical mouse semiconductor chip in which an image sensor

which detects a light from the optical unit and converts the light into an

electrical signal and a digital signal processing unit which computes and

processes a coordinate value of a cursor which is displayed on a computer

monitor using an electrical signal converted by the optical unit;

a transmission unit which transmits a coordinate value computed

by the optical mouse semiconductor chip to a computer body; and

a pad which includes a certain lattice pattern formed of lines or

dots of an opaque color on a surface having a light emitting surface, so

that more than one line among the lines of different direction lattice patterns are imaged in the image sensor.

5. The device of either claims 1 or 4, wherein a member having a

random reflection surface is paper.

6. The device of claim 4, wherein said light emitting surface includes

a pad formed of a back light component of a LCD monitor.

7. The device of either claim 1 or claim 4, wherein said optical mouse

semiconductor chip separately includes an image sensor and a digital

signal processing unit.

8. The device either claim 1 or claim 4, wherein said digital signal

processing unit may be substituted with a microprocessor.