Computer graphics processing and selective visual display system – Display peripheral interface input device – Touch panel
Reexamination Certificate
1999-07-09
2001-09-04
Shalwala, Bipin (Department: 2673)
Computer graphics processing and selective visual display system
Display peripheral interface input device
Touch panel
C250S559290, C178S018090
Reexamination Certificate
active
06285359
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a method and device for detecting a coordinate position. A touch-panel surface is formed by irradiating a substantially parallel light on the surface of a white board or a display unit and a position on the surface of the white board or the display unit where the light forming the touch-panel surface is blocked is detected. More particularly the invention relates to a method and device for detecting coordinate position in which identification of an incorrect position which occurs due to existence of a foreign substance, dust and dirt or the like on a reflecting member for reflecting a light beam from a light source can be prevented.
BACKGROUND OF THE INVENTION
As a conventional type of coordinate-position detecting device, there is one, for instance, comprising two light sources each for irradiating light in parallel with a display surface of a display unit while rotating. Reflecting sections are provided each for recursively reflecting the light from the light source in its incident direction, and detecting sections are provided at positions where the light sources are provided respectively each for receiving the reflected light from the reflecting section.
The two light sources irradiate, while changing the direction, light to the reflecting sections in parallel with the display surface of the display unit. Each of the reflecting sections recursively reflects the light to the light source. Each of the detecting sections provided at the position of the light source receives the light recursively reflected from the reflecting section. When the light is blocked by a finger or a pen, the detecting section detects the direction of the light source. Coordinates of the position indicated by the finger or the pen can be computed from a distance between the two light sources and the detected directions of the two light sources.
FIG. 16
is a general view of a coordinate-position detecting devices based on the conventional technology. The conventional type of coordinate-position detecting device shown in
FIG. 16
comprises a display unit
1601
having a rectangular display surface as a coordinate-position input area. Reflecting members
1602
A,
1602
B, and
1602
C are provided each for recursively reflecting an incident light back to the light source. Light scanners
1603
A and
1603
B are provided for irradiating a light beam while rotating and receiving the light reflected by any of the reflecting members. A computing section
1604
computes the coordinates indicated by a pen
1607
used for entering a coordinate position, and an interface
1605
outputs the coordinates of the pen
1607
computed by the computing section
1604
.
Each of the reflecting members
1602
A,
1602
B, and
1602
C is constructed with a corner cube array where a number of corner cube reflectors are arranged or a recursive reflecting tape, and its reflecting surface is a rectangle. The reflecting members
1602
A,
1602
B, and
1602
C are provided on right, left and lower side of the display unit
1601
so that each of the reflecting surfaces is perpendicular with respect to the display surface of the display unit
1601
.
The light scanners
1603
A and
1603
B are provided above the display unit
1601
at both edges thereof respectively. The light scanners
1603
A and
1603
B irradiate light to the reflecting members
1602
A,
1602
B, and
1602
C while changing their directions, and receive the reflected light from the reflecting members
1602
A,
1602
B, and
1602
C. When the light is blocked by the pen
1607
, the light scanners
1603
A and
1603
B detect that the light is blocked, and detect the angles &thgr;3 and &thgr;4 corresponding to the directions of the light scanners
1603
A and
1603
B at that point of time.
The computing section
1604
obtains the angles &thgr;3 and &thgr;4 from the light scanners
1603
A and
1603
B respectively, computes the coordinates (X2, Y2) indicated by the pen
1607
from the previously measured and inputted distance W2 between the light scanners and the angles &thgr;3 and &thgr;4, and sends the coordinates (X2, Y2) to a personal computer PC or the like through the interface
1605
.
In the coordinate-position detecting device having the reflecting member described above, when there is a foreign substance, dust or dirt (which will be collectively called as dirt) on the reflecting surface of a reflecting member, a light beam is blocked by this dirt and does not reach the reflecting surface or can not by reflected thereby. Therefore there occurs a malfunction such that it is determined as if an instruction is given by a pen on a display surface or the like despite there is no instruction given by a pen.
Especially, in the coordinate-position detecting device having light scanners provided above the display unit at both edges thereof and having reflecting members provided on right, left and lower side of the display unit, dirt is easily deposited on the reflecting surface of the reflecting member located in the lower side of the display unit which is facing in an opposite directed with respect to the direction of gravity. Further, when a white board is used in place of the display unit and something is written on it with a marker pen, dirt generated when the writing with the marker pen thereon is erased drops onto the reflecting surface of the reflecting member located in the lower side of the white board and blocks the light, which may again cause malfunction.
When the user notices the malfunction or notices that dirt is deposited on the reflecting surface of a reflecting member, he or she removes the dirt by cleaning such as wiping with a cloth in order to avoid the malfunction and then restarts using the board.
In the conventional technology, cleaning is carried out as necessary when dirt is deposited on the reflecting surface of a reflecting member. However, the deposited dirt may be a cause of malfunction because it is easy for the dirt to get deposited on the reflecting surface of a reflecting member located in the lower side of the white board or the display unit, and the work has to be interrupted frequently in order to clean the reflecting surface to accurately detect a coordinate position Thus, in the conventional technology a load of cleaning the reflecting surface onto the user has been quite heavy.
Since the reflecting surface of a reflecting member is fixed to the white board, it is quite difficult to clean the surface, and especially the corners of the reflecting members on the two sides tend to accumulate the dirt therein and it is difficult to clean the dirt in these corners.
Further, the corners formed by the reflecting members on two sides have the smallest incident angle of a light beam from a light source, so that reflectivity of the light from the light source is reduced at these corners. When there are variations in joints each of two reflecting members at the corners, the reflectivity is further reduced.
SUMMARY OF THE INVENTION
It is an object of the present invention to reduce, for the purpose of solving the problems described above, frequency of occurrence of malfunction, interruption of works, and the load of cleaning onto a user by making it difficult for the dirt to get deposited on the reflecting surface of a reflecting member.
It is another object of the present invention to easily clean the reflecting surface of a reflecting member.
It is another object of the present invention to enhance reflectivity of a light at the corner formed by the reflecting members on two sides.
In the present invention, angle of the reflecting surface of a recursively reflecting unit is adjusted by an angle adjusting unit. Thus, the angle between the surface of a white board or the display unit and the reflecting surface of the recursively reflecting unit can be adjusted to such an angle that the dirt does not get deposited on the reflecting surface or the surface can easily be cleaned.
In the present invention, angle between the reflecting surface of a reflecting member provided in the bottom side forming a r
Ito Takahiro
Ogasawara Tsutomu
Takekawa Kenichi
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Piziali Jeff
Ricoh & Company, Ltd.
Shalwala Bipin
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