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Claims  |
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What is claimed is:
1. A coordinate detecting apparatus including a display unit having a
separate control unit;
the display unit displaying data about contents to be displayed and being
superposed on a coordinate detecting unit for converting coordinate
information supplied from said display unit into coordinate data; and
said control unit transmitting and receiving the data about the contents to
be displayed and said coordinate data to and from a portion of said
coordinate detecting apparatus including said display unit superposed on
said coordinate detecting unit, said control unit being separate from said
portion,
said coordinate detecting apparatus comprising:
a display unit control means, disposed in said control unit, for
transferring a graphic control signal as said data about the contents to
be displayed to said display unit, said graphic control signal directly
controlling said display unit;
a driving power source disposed in said control unit, the driving power
source being connected to drive said display unit and said coordinate
detecting unit,
said portion of said coordinate detecting apparatus including said display
unit superposed on said coordinate detecting unit and said control unit
being connected to each other by a common integrated cable including at
least a signal line for transferring said graphic control signal to said
display unit, a signal line for transferring the coordinate data of said
coordinate detecting unit, and a power line for transferring power from
said driving power source to said display unit and said coordinate
detecting unit.
2. A coordinate detecting apparatus according to claim 1, wherein
said control unit includes a compressing circuit for compressing said data
about the contents to be displayed to transfer it to said portion of said
coordinate detecting apparatus including said display unit superposed on
said coordinate detecting unit by increasing a data transfer rate without
increasing or decreasing the amount of data, and
said portion of said coordinate detecting apparatus including said display
unit superposed on said coordinate detecting unit including a restoring
circuit for restoring compressed data about the contents to be displayed
by decreasing the data transfer rate.
3. A coordinate detecting apparatus according to claim 1, wherein said
portion of said coordinate detecting apparatus including said display unit
superposed on said coordinate detecting unit is accommodated in a thin
frame.
4. A coordinate detecting apparatus according to claim 3, wherein said
frame which accommodates said portion of said coordinate detecting
apparatus including said display unit superposed on said coordinate
detecting unit has a pivotally fastened foldable standing member on a
bottom side or a side surface thereof.
5. A coordinate detecting apparatus according to claim 1, wherein said
control unit is accommodated in a frame at least one side surface of which
is formed as a plane.
6. A coordinate detecting apparatus according to claim 5, wherein holding
means for holding said frame of said control unit on the surface of a disk
is provided on a bottom side of said frame of said control unit.
7. A coordinate detecting apparatus according to claim 5, wherein the size
of one side of a frame accommodating said portion of said coordinate
detecting apparatus including said display unit superposed on said
coordinate detecting unit and that of said at least one side surface of
said frame of said control unit are made to be substantially the same.
8. A coordinate detecting apparatus according to claim 1 wherein at least
control data, data about the contents to be displayed and power for
driving said display unit, and control data, coordinate data and power for
driving said coordinate detecting unit are transmitted and received
through one input/output port and said common integrated cable.
9. A coordinate detecting apparatus according to claim 1, wherein said
display unit comprises a liquid crystal display, said graphic control
signal comprises a digital graphic control signal and said display unit
control means comprises a liquid crystal controller outputting said
digital graphic control signal.
10. A coordinate detecting apparatus including a display unit having a
separate control unit:
the display unit displaying data about contents to be displayed and being
superposed on a coordinate detecting unit for converting coordinate
information supplied from said display unit into coordinate data; and
said control unit for transmitting and receiving data about the contents to
be displayed and said coordinate data to and from a portion of said
coordinate detecting apparatus including said display unit superposed on
said coordinate detecting unit, said control unit being separate from said
portion,
said coordinate detecting apparatus comprising:
a power source and an interface board located in a portion including said
control unit, said power source being connected for supplying power to
each of a plurality of circuits in said control unit, and said interface
board being insertable into an extension slot of said control unit,
said interface board having display unit control means, said display unit
control means being disposed in said control unit, for transferring a
graphic control signal as said data about the contents to be displayed to
said display unit, said graphic control signal directly controlling said
display unit;
a power supply circuit located in said interface board for supplying
driving power from said power source to said display unit and said
coordinate detecting unit as driving power source,
said portion of said coordinate detecting apparatus including said display
unit superposed on said coordinate detecting unit and said interface board
being connected to each other by a common integrated cable including at
least a signal line for transferring said graphic control signal to said
display unit, a signal line for transferring the coordinate data of said
coordinate detecting unit, and a power line for transferring power from
said power supply circuit to said display unit and said coordinate
detecting unit.
11. A coordinate detecting apparatus according to claim 10, wherein
said interface board includes a compressing circuit for compressing said
data about the contents to be displayed to transfer it to said portion of
said coordinate detecting apparatus including said display unit superposed
on said coordinate detecting unit by increasing a data transfer rate
without increasing or decreasing the amount of data, and
said portion of said coordinate detecting apparatus including said display
unit superposed on said coordinate detecting unit including a restoring
circuit for restoring compressed data about the contents to be displayed
by decreasing the data transfer rate.
12. A coordinate detecting apparatus according to claim 10, wherein said
portion of said coordinate detecting apparatus including said display unit
superposed on said coordinate detecting unit is accommodated in a thin
frame.
13. A coordinate detecting apparatus according to claim 12, wherein said
frame which accommodates said portion of said coordinate detecting
apparatus including said display unit superposed on said coordinate
detecting unit has a pivotally fastened foldable standing member on a
bottom side or a side surface thereof.
14. A coordinate detecting apparatus according to claim 10, wherein said
control unit is accommodated in a frame at least one side surface of which
is formed as a plane.
15. A coordinate detecting apparatus according to claim 13, wherein holding
means for holding said frame of said control unit on the surface of a disk
is provided on a bottom side of said frame of said control unit.
16. A coordinate detecting apparatus according to claim 14, wherein the
size of one side of a frame accommodating said portion of said coordinate
detecting apparatus including said display unit superposed on said
coordinate detecting unit and that of said at least one side surface of
said frame of said control unit are made to be substantially the same.
17. A coordinate detecting apparatus according to claim 10, wherein said
display unit comprises a liquid crystal display, said graphic control
signal comprises a digital graphic control signal and said display unit
control means comprises a liquid crystal controller outputting said
digital graphic control signal.
18. A coordinate detecting apparatus with a display unit for displaying
data about contents to be displayed, said display unit being superposed on
a coordinate detecting unit and said coordinate detecting unit converting
coordinate information supplied from said display unit into coordinate
data, comprising:
a common integrated cable for connecting said coordinate detecting
apparatus with said display unit to a control unit, said control unit
transmitting and receiving data about the contents to be displayed and
said coordinate data to and from said coordinate detecting apparatus, said
common integrated cable including (a) a signal line for transferring a
graphic control signal as the data about contents to be displayed to said
display unit, said graphic control signal directly controlling said
display unit, and (b) a signal line for transferring the coordinate data
of said coordinate detecting unit,
driving power for driving said display unit and said coordinate detecting
unit being supplied from said control unit via said integrated cable.
19. A coordinate detecting apparatus according to claim 18 further
comprising a restoring circuit for restoring said data about the contents
to be displayed which has been compressed by increasing a data transfer
rate without increasing or decreasing the amount of data and transferred.
20. A coordinate detecting apparatus according to claim 18, wherein said
coordinate detecting apparatus is accommodated in a thin frame.
21. A coordinate detecting apparatus according to claim 20, wherein said
frame which accommodates said coordinate detecting apparatus has a
pivotally fastened foldable standing member on a bottom side or a side
surface thereof.
22. A coordinate detecting apparatus with a display unit according to claim
18 wherein at least control data, data about the contents to be displayed
and power for driving said display unit, and control data, coordinate data
and power for driving said coordinate detecting unit are transmitted and
received through one input/output port and said common integrated cable.
23. A coordinate detecting apparatus according to claim 18, wherein said
display unit comprises a liquid crystal display, said graphic control
signal comprises a digital graphic control signal and said display unit
control means comprises a liquid crystal controller outputting said
digital graphic control signal.
24. A control unit for transmitting and receiving data about the contents
to be displayed and coordinate data to and from a coordinate detecting
apparatus with a display unit for displaying data about contents to be
displayed, said display unit being superposed on a coordinate detecting
unit and said coordinate detecting unit converting coordinate information
supplied from said display unit into coordinate data, said control unit
being separate from said coordinate detecting apparatus with said display
unit, said control unit comprising:
display unit control means for transferring a graphic control signal as
said data about contents to be displayed to said display unit, said
graphic control signal directly controlling said display unit;
a driving power source arranged to drive said display unit and said
coordinate detecting unit,
said control unit being connected to said coordinate detecting apparatus
with said display unit by a common integrated cable including at least (a)
a signal line for transferring said graphic control signal to said display
unit, (b) a signal line for transferring the coordinate data of said
coordinate detecting unit, and (c) a power line for transferring power to
said display unit and said coordinate detecting unit from said driving
power source.
25. A control unit according to claim 24, wherein at least control data,
data about the contents to be displayed and power for driving said display
unit and control data, coordinate data and power for driving said
coordinate detecting unit are transmitted and received through one
input/output port.
26. A control unit according to claim 24 further comprising a compressing
circuit for compressing said data about the contents to be displayed to
transfer it to said coordinate detecting apparatus with said display unit
by increasing a data transfer rate without increasing or decreasing the
amount of data.
27. A control unit according to claim 24, wherein said control unit is
accommodated in a frame at least one side surface of which is formed as a
plane.
28. A control unit according to claim 27, wherein holding means for holding
said frame of said control unit on the surface of a disk is provided on a
bottom side of said frame of said control unit.
29. A control unit according to claim 28, wherein the size of a bottom side
of a frame of said coordinate detecting apparatus with said display unit
and that of a surface of said frame of said control unit are made to be
substantially the same.
30. A control unit according to claim 24, wherein said display unit
comprises a liquid crystal display, said graphic control signal comprises
a digital graphic control signal and said display unit control means
comprises a liquid crystal controller outputting said digital graphic
control signal.
31. An interface board which can be inserted into an extension slot of a
control unit, said interface board transmitting and receiving data about
the contents to be displayed and coordinate data to and from a coordinate
detecting apparatus with a display unit for displaying data about contents
to be displayed, said display unit being superposed on a coordinate
detecting unit and said coordinate detecting unit converting coordinate
information supplied from said display unit into coordinate data, said
control unit being separate from said coordinate detecting apparatus with
said display unit, said interface board comprising:
a display unit control means for transferring a graphic control signal as
said data about contents to be displayed to said display unit, said
graphic control signal directly controlling said display unit,
a power supply circuit for supplying power from a power source of said
control unit to said display unit and said coordinate detecting unit as a
driving power source.
32. An interface board according to claim 31, wherein at least control
data, data about the contents to be displayed and power for driving said
display unit and control data, coordinate data and power for driving said
coordinate detecting unit are transmitted and received through one
input/output port.
33. An interface board according to claim 31 further comprising a
compressing circuit for compressing said data about the contents to be
displayed by increasing a data transfer rate without increasing or
decreasing the amount of data to transfer it to said coordinate detecting
apparatus with said display unit.
34. An interface board according to claim 31, wherein said display unit
comprises a liquid crystal display, said graphic control signal comprises
a digital graphic control signal and said display unit control means
comprises a liquid crystal controller outputting said digital graphic
control signal.
35. A coordinate detecting apparatus with a display unit of a type having a
separate control unit, in which
said display unit displays data about contents to be displayed and said
display unit is superposed on a coordinate detecting unit for converting
coordinate information supplied from said display unit into coordinate
data; and
said control unit transmits and receives data about the contents to be
displayed and said coordinate data to and from a portion of said
coordinate detecting apparatus including said display unit superposed on
said coordinate detecting unit, said control unit being separate from said
portion,
said coordinate detecting apparatus comprising:
a lighting unit for lighting up said display unit from the rear or the side
thereof,
display unit control means and a driving power source located in a portion
including said control unit, the display unit control means transferring a
graphic control signal as said data about contents to be displayed to said
display unit, said graphic control signal directly controlling said
display unit, and the driving power source being arranged for driving said
lighting unit, said display unit and said coordinate detecting unit,
said portion of said coordinate detecting apparatus including said display
unit superposed on said coordinate detecting unit and said control unit
being connected to each other by a common integrated cable including at
least a signal line for transferring said graphic control signal to said
display unit, a signal line for transferring the coordinate data of said
coordinate detecting unit, and a power line for transferring power from
said driving power source to said lighting unit, said display unit and
said coordinate detecting unit.
36. A coordinate detecting apparatus according to claim 35, wherein said
display unit comprises a liquid crystal display, said graphic control
signal comprises a digital graphic control signal and said display unit
control means comprises a liquid crystal controller outputting said
digital graphic control signal.
37. A coordinate detecting apparatus with a display unit of a type having a
separate control unit, in which said display unit displays data about
contents to be displayed and said display unit is superposed on a
coordinate detecting unit for converting coordinate information supplied
from said display unit into coordinate data; and
said control unit transmits and receives data about the contents to be
displayed and said coordinate data to and from a portion of said
coordinate detecting apparatus including said display unit superposed on
said coordinate detecting unit, said control unit being separate from said
portion of said coordinate detecting apparatus with said display unit;
said coordinate detecting apparatus comprising:
a portion including said control unit, said control unit having a display
unit control means for transferring a graphic control signal as said data
about the contents to be displayed to said display unit, said graphic
control signal directly controlling said display unit.
38. A coordinate detecting apparatus according to claim 37, wherein said
display unit comprises a liquid crystal display, said graphic control
signal comprises a digital graphic control signal and said display unit
control means comprises a liquid crystal controller outputting said
digital graphic control signal.
39. In combination,
a first housing including:
(a) a tablet having two coordinate directions for detecting coordinates of
an object in the two coordinate directions and for deriving tablet output
signals indicative of the object position in said two coordinate
directions,
(b) a controller connected to the tablet for supplying control signals to
the tablet and responding to the tablet output signals to derive a serial
signal indicative of the position of the object in said two coordinate
directions,
(c) a two coordinate display for the two coordinate directions of the
tablet, the display providing a graphic display of the object in the two
coordinate directions in response to a digital signal having a bandwidth
less than that of a video signal, and
(d) a power supply circuit for converting a DC input voltage into DC power
supply voltages for the display and the controller;
a second housing including:
(a) a power source for deriving the DC input voltage for the power supply
circuit,
(b) a signal bus,
(c) a serial signal controller for deriving input signals for the
controller of the first housing and responsive to the serial signal
indicative of the object position in said two coordinate directions, the
serial signal controller supplying the bus with a signal indicative of the
object position in said two coordinate directions,
(d) a controller for the display responsive to the signal on the bus
indicative of the object position in said two coordinate directions for
deriving the digital signal having a bandwidth less than that of a video
signal and indicative of the object position in the two coordinate
directions; and
an integrated cable connected between the first and second housings
including first, second and third lines, the first line being connected
between the power source and the power supply circuit for supplying the DC
input voltage to the power supply circuit from the power source, the
second line being connected between the serial signal controller and the
controller of the first housing for coupling the serial signal indicative
of the object position from the controller of the first housing to the
serial signal controller and for coupling the input signal for the
controller of the first housing from the serial signal controller to the
controller of the first housing, the third line being connected between
the controller for the display and the display for coupling the digital
signal from the controller for the display to the display.
40. An apparatus according to claim 39, wherein said first housing is
supported by a foldable standing member pivotally fastened to a side
thereof such that an operator can variably position said first housing
during operation of the apparatus.
41. An apparatus according to claim 39, wherein said second housing is
located separate from said first housing and said integrated cable
mutually and externally interconnects said first and second housings.
42. A method of using a coordinate detecting apparatus having a first
coordinate detecting and output display housing and a second power supply
and signal control housing, said first and second housings being mutually
interconnected by a single integrated cable including at least first,
second and third lines, said method comprising the steps of:
detecting coordinates of an object position in said first housing in two
coordinate directions and deriving input signals indicative of said object
position in said two coordinate directions;
processing said input signals in said first housing to derive graphic
control signals;
electronically transmitting said graphic control signals from said first
housing to said second housing, said electronic transmittance occurring
via said second line of said integrated cable at a graphic control signal
transmittal frequency less than that of a video signal;
controlling and enhancing said graphic control signals in said second
housing according to a program of a computer to generate serial signals;
supplying electric power to said first housing from said second housing,
said supplying of electric power occurring via said first line of said
integrated cable;
electronically transmitting said serial signals from said second housing to
said first housing via said third line of said integrated cable at a
serial signal transmittal frequency;
processing said digital serial signals in said first housing to derive
coordinate display signals; and
displaying said display signals on an output display in said first housing.
43. A method according to claim 42, wherein said graphic control signals
and said serial signals are digital signals.
44. The method according to claim 42, wherein said graphic control signal
transmittal frequency and said serial signal transmittal frequency are
greater than 1 Mhz and less than 15 Mhz.
45. A method according to claim 43, wherein said graphic control signal
transmittal frequency is greater than 1 Mhz and less than 15 Mhz and said
serial signal transmittal frequency is more than 29 Mhz.
46. In combination,
a first housing including:
(a) a tablet having two coordinate directions for detecting coordinates of
an object in the two coordinate directions and for deriving tablet output
signals indicative of the object position in said two coordinate
directions,
(b) a controller connected to the tablet for supplying control signals to
the tablet and responding to the tablet output signals to derive a serial
signal indicative of the position of the object in said two coordinate
directions,
(c) a two coordinate display for the two coordinate directions of the
tablet, the display providing a graphic display of the object in the two
coordinate directions in response to a digital signal, and
(d) a power supply circuit for converting a DC input voltage into DC power
supply voltages for the display and the controller;
a second housing including:
(a) a power source for deriving the DC input voltage for the power supply
circuit,
(b) a signal bus,
(c) a serial signal controller for deriving input signals for the
controller of the first housing and responsive to the serial signal
indicative of the object position in said two coordinate directions, the
serial signal controller supplying the bus with a signal indicative of the
object position in said two coordinate directions,
(d) a controller for the display responsive to the signal on the bus
indicative of the object position in said two coordinate directions for
deriving the digital signal indicative of the object position in the two
coordinate directions; and
an integrated cable connected between the first and second housings
including first, second and third lines, the first line being connected
between the power source and the power supply circuit for supplying the DC
input voltage to the power supply circuit from the power source, the
second line being connected between the serial signal controller and the
controller of the first housing for coupling the serial signal indicative
of the object position from the controller of the first housing to the
serial signal controller and for coupling the input signal for the
controller of the first housing from the serial signal controller to the
controller of the first housing, the third line being connected between
the controller for the display and the display for coupling the digital
signal from the controller for the display to the display.
47. An apparatus according to claim 46, wherein said first housing is
supported by a foldable standing member pivotally fastened to a side
thereof such that an operator can variably position said first housing
during operation of the apparatus.
48. An apparatus according to claim 46, wherein said second housing is
located separate from said first housing and said integrated cable
mutually and externally interconnects said first and second housings.
49. A method for use in a coordinate detecting apparatus having a first
coordinate detecting and output display housing and a second power supply
and signal control housing, said first and second housings mutually
interconnected by a single integrated cable including at least first,
second and third lines, said method comprising the steps of:
detecting coordinates of an object position in said first housing in two
coordinate directions and deriving input signals indicative of said object
position in said two coordinate directions;
processing said input signals in said first housing to derive serial
signals;
electronically transmitting said serial signals from said first housing to
said second housing, said electronic transmittance occurring via said
second line of said integrated cable;
controlling said serial signals in said second housing according to a
program of a computer to generate a graphic control signal;
supplying electric power to said first housing from said second housing,
said supplying of electric power occurring via said first line of said
integrated cable;
electronically transmitting said graphic control signal from said second
housing to said first housing via said third line of said integrated cable
at a graphic control signal transmittal frequency; and
displaying said graphic control signal on an output display in said first
housing.
50. A method according to claim 49, wherein said graphic control signals
are digital signals.
51. A method according to claim 49, wherein said graphic control signal
transmittal frequency is greater than 1 Mhz and less than 15 Mhz. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a coordinate detecting apparatus with a
display unit of a type having a separated control unit and arranged in
such a manner that the coordinate detecting apparatus with the display
unit constituted by superposing a flat type display unit on a coordinate
detecting unit is connected to a control unit disposed separably by a
means of a cable. More particularly, the present invention relates to a
coordinate detecting apparatus with a display unit of a type having a
separated control unit having only one connection cable and thereby
exhibiting improved handling facility.
2. Related Art Statement
Hitherto, an apparatus of the aforesaid type has been constituted by
superposing a plate-like display unit for displaying the contents to be
operated by the control unit in a real time manner on a coordinate
detecting unit acting as an input unit for inputting data to the control
unit. In the aforesaid apparatus, the position indicated by a coordinate
indicator is detected, so that coordinate data or data about a handwritten
character or the like formed into a numeral is transferred to the control
unit via the cable. Furthermore, data about the contents to be displayed
supplied from the control unit is received via a cable. An apparatus of
this type is disclosed in detail in Japanese Patent Laid-Open No.
63-115218 titled "POSITION DETECTING APPARATUS" filed by the applicant of
the present invention.
FIG. 15 is a perspective view of the components of a typical conventional
coordinate detecting apparatus with a display unit of a type having a
separated control unit. A coordinate detecting apparatus or tablet 51 with
a display unit is mainly composed of a coordinate detecting unit disposed
in a frame 56 and a display unit 55 superposed on the coordinate detecting
unit. In the conventional apparatus shown in FIG. 15, three cables connect
the coordinate detecting apparatus 51 with the display unit. That is, a
serial signal cable 57 for transmitting/receiving coordinate data or the
like to and from a control unit 52 (hereinafter called a computer body, if
necessary), a video signal cable 58 for transmitting/receiving data about
the contents to be displayed to and from the computer body 52 and a power
supply cable 59 through which power is supplied from a power supply unit
53 are connected to the coordinate detecting apparatus 51 with the display
unit.
FIG. 16 is a block diagram of an essential portion of the apparatus shown
in FIG. 15. The coordinate detecting apparatus 51 with the display unit is
mainly composed by superposing the display unit 55 on a coordinate
detecting unit 54. The conventional apparatus shown in FIG. 16 further
includes a backlight 61 disposed on the reverse side of the display unit
55. Although the display unit 55 may comprise a plasma display or a
so-called reflecting type liquid display each of which is not coupled with
the backlight 61, the backlight 61 structure shown in FIG. 16 must be used
in a case including a so-called transmission type liquid crystal display
to attain brightness advantages.
The display unit 55 is controlled by a display unit control means 62
disposed in the frame 56 of the coordinate detecting apparatus 51 with the
display unit. The coordinate detecting unit 54 is controlled by a
detecting unit control means 64 also disposed in the frame 56. A power
supply circuit 63 supplies power required to operate the backlight 61, the
display unit control means 62, and the detecting unit control means 64,
and the like. The power supply unit 53 converts a domestic 100 or 200 V AC
a DC level of about 10 V supplied to the power supply circuit 63 via a
power supply cable 59. The power supply circuit 63 converts the 10 volt DC
level into proper driving voltage for each of the backlight 61, the
display unit control means 62 and the detecting unit control means 64 so
as to supply it to these elements.
A CRT control means 70 transfers a video signal representing displayed data
to the display unit control means 62 via the video signal cable 58; the
video signal is converted into a graphic control signal by the display
unit control means 62. As a result, data about the contents to be
displayed are displayed on the display unit 55. The display unit control
means 62 is connected to the CRT control means 70 in the computer body 52
via the video signal cable 58 so as to transmit/receive the signal which
denotes the contents to be displayed. The detecting unit control means 64
is connected via the serial signal cable 57, to a serial signal control
means 71 disposed in the computer body 52 so as to transmit/receive a
signal which denotes coordinate data or the like.
The computer body 52 comprises a CPU 65 and a bus 68 connected to the CPU
65, the computer body 52 further comprising a ROM 66, a RAM 67, the CRT
control means 70 and the serial signal control means 71 respectively
connected to the bus 68. The power required for each of the aforesaid
circuits is derived from a power source 69. The power source 69 is a power
supply means provided independently from the power supply unit 53. In this
description, the "CPU" is a central processing unit, the "ROM" is a read
only memory memorizing a control program for controlling this apparatus
and the like, the "RAM" is a random access memory which stores coordinate
data transferred from the coordinate detecting apparatus 51 associated
with the display unit and the like and the "CRT" is a display unit having
a so-called cathode-ray tube.
Since the conventional coordinate detecting apparatus with the display unit
has three cables connected thereto, the aforesaid cables deteriorate the
handling facility of the apparatus. That is, there arises a problem in
terms of the handling facility at the time of the data input operation and
the transportation of the apparatus.
Furthermore, since a relatively high transferring frequency is used in a
case where the video signal is employed to transfer data, a countermeasure
must be taken against generation of noise affecting the environment.
Another problem arises in that there is an excessive limit in designing the
display unit control means such as a liquid crystal controller for
receiving a video signal and controlling the display unit as compared with
a case where it is directly connected to the bus of the computer body.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a coordinate detecting
apparatus with a display unit of a type having a separated control unit
which is capable of overcoming the aforesaid problems, in which a control
unit and a coordinate detecting apparatus with a display unit can be
connected to each other by means of one cable and the frequency for
transmitting/receiving data to and from the control unit is reduced,
whereby the circuit for the display control means can be freely designed
and the handling facility of the coordinate detecting apparatus with the
display unit is improved.
Another object of the present invention is to provide an improved interface
between an existing computer body and the improved coordinate detecting
apparatus with the display unit of a type having a separate control unit.
To achieve the aforesaid object, according to one aspect of the invention,
there is provided a coordinate detecting apparatus with | | |
