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Claims  |
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What is claimed is:
1. A programmable control device, comprising:
a first bus line to which a first control unit and a first connection unit
are connected, said first control unit being connected to a device and
operating to control said device and said first control unit being
connected to said first connection unit through the first bus; and
a second bus line, to which a second control unit and a second connection
unit are connected, said second control unit being connected to said
second connection unit through the second bus and said first and second
connection units being detachably connectable to each other, and said
second control unit being coupled to the first control unit via the second
bus line, the second connection unit, the first connection unit and the
first bus line to control said first control unit according to information
stored in a storage unit connected to said second control unit,
wherein control of said device by said first control unit differs in the
cases in which said second control unit is connected and in which said
second control unit is not connected, respectively.
2. A programmable control device according to claim 1, wherein said second
control unit, said storage unit, said second bus line and said second
connection unit are accommodated within a box having the shape of a card,
the second connection unit accommodated within the box being connectable
to the first connection unit.
3. A programmable control device according to claim 1, wherein said second
control unit and said storage unit are configured in one chip.
4. A programmable control device according to claim 3, wherein said second
control unit and said storage unit configured in the one chip, said second
bus line and said second connection unit are accommodated within a box
having a card-like shape.
5. A programmable control device according to claim 1, further comprising a
third connection unit connected to said storage unit, and an input unit to
be connected to said third connection unit, for inputting information to
said storage unit.
6. A programmable control device according to claim 5, wherein said second
control unit controls said first control unit according to the information
input to said storage unit.
7. A programmable control device comprising:
a first bus line, to which a first control unit and a switching unit are
connected, said first control unit being connected to a device and
operating to control said device, said first control unit being connected
to said switching unit through said first bus line and said switching unit
connecting one of a first connection unit and a fourth connection unit to
the first bus line;
a second bus line, to which a second control unit and a second connection
unit are connected, said second control unit being connected to said
second connection unit through the second bus line and said first and
second connection units being detachably connectable to each other, and
said second control unit being coupled to the first control unit via the
second bus line, the second connection unit, the switching unit and the
first bus line to control said first control unit according to information
stored in a first storage unit connected to said second control unit; and
a third bus line, to which a third control unit and a third connection unit
are connected, said third control unit being connected to said third
connection unit through the third bus line and said third and fourth
connection units being detachably connectable to each other, said third
control unit being coupled to the first control unit via the third bus
line, the third connection unit, the switching unit and the first bus line
to control said first control unit according to information stored in a
second storage unit connected to said third control unit, and said first
control unit being controlled by one of said second control unit and said
third control unit connected by said switching unit.
8. A programmable control device according to claim 7, wherein said second
control unit and said first storage unit are configured in a first chip.
9. A programmable control device according to claim 8, wherein said third
control unit and said second storage unit are configured in a second chip.
10. A programmable control device according to claim 9, wherein said second
control unit and said first storage unit configured in the first chip, and
said second bus line and said second connection unit are accommodated
within a first box having a card-like shape.
11. A programmable control device according to claim 10, wherein said third
control unit and said second storage unit configured in the second chip,
and said third bus line and said third connection unit are accommodated
within a second box having a card-like shape.
12. A programmable control device according to claim 7, wherein said second
control unit, said first storage unit, said second bus line and said
second connection unit are accommodated within a box having a card-like
shape.
13. A programmable control device according to claim 12, wherein said third
control unit, said second storage unit, said third bus line and said third
connection unit are accommodated within a box having a card-like shape.
14. A programmable control device according to claim 7, further comprising
a fifth connection unit connected to said first storage unit, and an input
unit to be connected to said fifth connection unit, for inputting
information to said first storage unit.
15. A programmable control device according to claim 14, wherein said
second control unit controls said first control unit according to the
information input to said first storage unit.
16. A programmable control device, comprising:
a first bus line, to which a first control unit and a switching unit are
connected, said first control unit being connected to a device and
operating to control said device, said first control unit being connected
to said switching unit through said first bus and said switching unit
connecting one of a first connection unit and a third connection unit to
said first bus line; and
a second bus line, to which a second control unit and a second connection
unit are connected, said second control unit being connected to said
second connection unit through the second bus line and said first and
second connection units being detachably connectable to each other, said
second control unit being coupled to the first control unit via the second
bus line, the second connection unit, the switching unit and the first bus
line to control said first control unit according to information stored in
a first storage unit connected to said second control unit,
wherein control of said device by said first control unit differs in the
cases in which said second control unit is connected and in which said
second control unit is not connected, respectively.
17. A programmable control device according to claim 16, wherein said
second control unit and said first storage unit are configured in one
chip.
18. A programmable control device according to claim 17, wherein said
second control unit and said first storage unit configured in the one
chip, said second bus line and said second connection unit are within a
box having a card-like shape.
19. A programmable control device according to claim 16, further comprising
a fourth connection unit connected to said first storage unit, and an
input unit to be connected to said fourth connection unit, for inputting
information to said first storage unit.
20. A programmable control device according to claim 19, wherein said
second control unit controls said first control unit according to the
information input to said first storage unit.
21. In a programmable control device in which a first connection unit is
connected to a first control unit through a first bus and the first
control unit is connected to a device, a second control unit is connected
to a second connection unit through a second bus line, the second control
unit being coupled to the first control unit through the second bus line,
the second connection unit, the first connection unit and the first bus,
and said first and second connection units being detachably connectable to
each other, the method comprising the steps of:
controlling the device with the first control unit; and
controlling the first control unit according to information stored in a
storage unit connected to the second control unit when the second control
unit is connected through the first and second connection units,
wherein, the control of the device by the first control unit when the
second control unit is connected differs from the control of the device by
the first control unit when the second control unit is not connected.
22. The method according to claim 21, wherein said second control unit,
said storage unit, said second bus line and said second connection unit
are accommodated within a box having the shape of a card, the second
connection unit accommodated within the box being connectable to the first
connection unit.
23. The method according to claim 21, wherein said second control unit and
said storage unit are configured in one chip.
24. The method according to claim 23, wherein said second control unit and
said storage unit configured in the one chip, said second bus line and
said second connection unit are accommodated within a box having a
card-like shape.
25. The method according to claim 21, in which the programmable control
device further comprises a third connection unit connected to said storage
unit, and an input unit to be connected to said third connection unit, for
inputting information to said storage unit.
26. The method according to claim 25, wherein said second control unit
controls said first control unit according to the information input to
said storage unit.
27. In a programmable control device in which a first connection unit is
connected to a switching unit through a first bus line and to a device,
the switching unit connecting one of the first connection unit and a third
connection unit to the first bus line and in on which a second control
unit is connected to a second connection unit through a second bus line,
the second control unit being coupled to the first control unit via the
second bus line, the second connection unit, the switching unit and the
first bus line, the first and second connection units being detachably
connectable to each other, the method comprising the steps of:
controlling the device with the first control unit; and
controlling the first control unit according to information stored in a
first storage unit connected to the second control unit when the first and
second connection units are connected,
wherein, the control of the device by the first control unit when the
second control unit is connected differs from the control of the device by
the first control unit when the second control unit is not connected.
28. The method according to claim 27, wherein said second control unit and
said first storage unit are configured in one chip.
29. The method according to claim 28, wherein said second control unit and
said first storage unit are configured in the one chip, said second bus
line and said second connection unit are within a box having a card-like
shape.
30. The method according to claim 27, wherein the programmable control
device further includes a fourth connection unit connected to said first
storage unit, and an input unit to be connected to said fourth connection
unit, for inputting information to said first storage unit.
31. The method according to claim 30, wherein said second control unit
controls said first control unit according to the information input to
said first storage unit. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a programmable control device, and more
particularly, to a device whose control unit is connected to a
general-purpose bus to externally control a controlled unit.
2. Description of the Related Art
Heretofore, two types of devices each of which incorporates a control
function have been known, i.e., a type in which the operational function
of the device is controlled by hardware logic, and a type in which control
programs and a CPU (central processing unit) are incorporated within the
device, and the CPU controls the operational function of the device
according to the control programs. The latter type device includes an
arrangement for externally inputting a control program for a computer or
the like, whereby the device can have an entirely different function by
use of the input control program although the same hardware is used.
FIG. 3 is a block diagram showing an example of the configuration of a
conventional programmable control device.
In FIG. 3, a CPU 201 controls the entire device by interpreting and
executing programs stored in a ROM (read-only memory) 202. A RAM (random
access memory 203 functions as a work memory to be used when the CPU 201
performs its operation. The ROM 202 and the RAM 203 are selected by
addresses output from the CPU 201 to an address bus S201. When the ROM 202
is selected, the contents of the memory are output to the data bus S202.
When the RAM 203 is selected, data are input and output via the data bus
S202. A first I/O unit (input/output interface unit) 204 is selected by an
I/O address output from the CPU 201. The first I/O unit 204 controls an
information display unit 205 by transmitting control data output from the
CPU 201 to the information display unit 205. A second I/O unit 208
controls an information output unit 207 by transmitting control data
output from the CPU 201 to the information output unit 207, in the same
manner as the first I/O unit 204. Thus, information is output to a
mechanism control unit (not shown) provided within the device, or outside
of the apparatus. A third I/O unit 208 outputs control information and
other information from an information input unit 209 to the CPU 201. A
fourth I/O unit 210 outputs control information and other information
detected by an information detection unit 211 to the CPU 201.
However, even a device which can be controlled by inputting a control
program from the outside (a programmable control device) has the problem
that it becomes obsolete within a very short time in accordance with
technical progress, since the same incorporated hardware is used.
That is, while the performance of the CPU 201, and the capacity, processing
speed and the like of the memory, such as the RAM 20S, advance day by day
in accordance with progress in the current semiconductor technology, a
device having hardware that is fixed cannot accommodate components
developed by such new technology in its structure. Accordingly, a process
of developing a new device which accommodates components developed by the
new technology is in many cases adopted. As a result, the lifetime of a
product shipped to the market is shortened by being replaced by a
next-generation product, causing waste of available resources.
SUMMARY OF THE INVENTION
The present invention has been made in consideration of the above-described
problems in the prior art.
It is an object of the present invention to provide a programmable control
device which can easily improve its function by effectively utilizing its
existing hardware, even if the existing function of a controller or the
like provided within the device becomes obsolete, by an arrangement
through which a new controller can be externally connected to a bus of the
device.
The invention is directed to a programmable control device in which a first
control unit for controlling a device connected thereto and a first
connection unit are connected to a first bus line. A second control unit
that controls the first control unit and a second connection unit are
connected to a second bus line. The first control unit is controlled
according to information stored in the second control unit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating the configuration of a principal
part of a programmable control device according to an embodiment of the
present invention;
FIG. 2 is a block diagram illustrating the configuration of a principal
part of a programmable control device according to another embodiment of
the present invention;
FIG. 3 is a block diagram showing an example of the configuration of a
conventional programmable control device;
FIG. 4 is a diagram showing an external appearance of a case having a
cable-like shape which accommodates the programmable control unit of the
present invention;
FIG. 5 is a schematic diagram illustrating still another embodiment of the
present invention;
FIG. 6 is a block diagram showing a first application illustrative of the
present invention;
FIG. 7 is a block diagram showing a second application illustrative of the
present invention;
FIG. 8 is a block diagram showing a third application illustrative of the
present invention;
FIG. 9 is a block diagram showing a fourth application illustrative of the
present invention;
FIG. 10 is a block diagram showing a fifth application illustrative of the
present invention; and
FIG. 11 is a block diagram showing a sixth application illustrative of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a diagram illustrating the configuration of a principal part of a
programmable control device according to an embodiment of the present
invention. The configuration and the operation of the device will now be
explained.
In FIG. 1, a unit 101 to be controlled is the main body of the device to be
controlled by a programmable control unit 102. The programmable control
unit 102 includes a one-chip microcomputer 115, serving as a control unit
to control the controlled device 101, and peripheral circuitry, such as a
clock-signal generation circuit (not shown) and the like, for operating
the one-chip microcomputer 115. The one-chip microcomputer 115 includes
circuitry, such as a ROM for programs, a RAM, an I/O port and the like.
A control-unit-side bus 104 is connected to a controlled-unit-side bus 105
via a connection unit 103. The one-chip microcomputer 115 can externally
control the controlled unit 101 via the control-unit-side bus 104. In the
present embodiment, each of the control-unit-side bus 104 and the
controlled-unit-side bus 105 includes an address bus and a data bus, each
having 32 bits, a power supply, and control-signal lines for memory
control signals, DMA (direct memory access) control signals, interrupt
control signals for the CPU, system clock signals and the like. A first
I/O unit 106 displays control information and other information of the
control-unit-side bus 104 received via the connection unit 103 and the
controlled-unit-side bus 105 on an information display unit 111. A second
I/O unit 107 outputs control information and other information of the
control-unit-side bus 104 received via the connection unit 103 and the
controlled-unit-side bus 105 to an information output unit 114. A third
I/O unit 108 outputs information input from an information input unit 112
to the control-unit-side bus 104 via the controlled-unit-side bus 105 and
the connection unit 103. A fourth i/O unit 109 outputs control information
and other information detected by an information detection unit 113 to the
control-unit-side bus 104 via the controlled-unit-side bus 105 and the
connection unit 103.
As shown in FIG. 1, the control unit previously incorporated in the main
body of the device is separated from the main body of the device, that is,
the device is divided into the unit 101 to be controlled and the program
control unit 102. In operating the device, the control-unit-side bus 104
is connected to the controlled-unit-side bus 105 via the connection unit
103. Hence, if the function of the CPU and the memory are significantly
improved with respect to the performance of the existing hardware, the
performance of the device can be increased without substantially changing
configuration of the hardware of the controlled unit 101 by updating only
the programmable control unit 102. It is assumed that the
control-unit-side bus 104 and the controlled-unit-side bus 105 are
standardized and invariable.
Thus, the programmable control device of the present embodiment is
configured so that the controller of the programmable control unit
controls the unit to be controlled according to control programs stored in
its storage unit when the programmable control unit is connected to the
unit to be controlled via the connection unit. Hence, in the programmable
control device of the present invention, the unit to be controlled can
execute various kinds of processing with improved functionality by
instructions from an external CPU (the programmable control unit) whose
function has been easily improved.
In addition, by configuring the storage unit and the controller in the form
of one chip, the size of the programmable control unit can be reduced.
In the above-described embodiment, an explanation has been provided of a
case in which the programmable control unit 102 is configured as the
one-chip microcomputer 115. However, as shown in FIG. 2, the programmable
control unit may be configured as a CPU 116, a ROM 117, a RAM 118, an I/O
port 119 and the like. In this case, an input setting unit 120 or the like
may be connected to the I/O port 119 via a connection unit 121 so that
parameters or the like desired to be set in the RAM 118 can be arbitrarily
set via the I/O port 119.
By thus configurating the programmable control unit so that arbitrary
information can be set from the input setting unit 120 in the RAM 118,
serving as the storage unit, it is possible to easily modify fixed
parameters or the like.
FIG. 2 is a block diagram illustrating the configuration of a principal
part of a programmable control device according to another embodiment of
the present invention. In FIG. 2, there are shown programmable control
units 102A and 102B. The programmable control unit 102A has the same
function as the programmable control unit 102 shown in FIG. 1. The
programmable control unit 102B can control the unit 101 to be controlled
by being connected to the connection unit 103.
As shown in FIG. 5, a plurality of connection units 103 may be provided so
that the user can select one of the programmable control units 102A and
102B by means of a DIP (dual in-line package) switch SW or the like in a
state in which the programmable control units 102A and 102B are
simultaneously connected to the respective connection units 103.
While in the above-described embodiments, the shape of the programmable
control unit is not limited, the programmable control unit may, for
example, be accommodated in a box having the shape of a card shown in FIG.
4, and may be connected to the controlled-unit-side bus 105 by connecting
a connector unit 42 of a card 41 to the connection unit 103.
As explained above, in the present invention, if the programmable control
unit is connected to the unit to be controlled via the connection unit,
the controller of the programmable control unit controls the unit to be
controlled according to control programs stored in the storage unit.
Hence, the unit to be controlled can be controlled according to various
kinds of updated control programs by externally changing the controller
without changing the configuration of the hardware of the unit to be
controlled.
In addition, since the storage unit and the controller are configured in
one chip, the size of the programmable control unit can be reduced.
Moreover, since the setting arrangement is connected to the programmable
control unit so that various kinds of parameters or the like for the unit
to be controlled stored in the storage unit can be rewritten, it is
possible to set appropriate updated parameters, for example, in order to
deal with a bug or the like in the control program of the programmable
control unit.
Accordingly, it is possible to externally control the unit to be controlled
at a processing speed corresponding to the control capability of the
connected programmable control unit. Hence, processing can be performed at
a speed higher than a conventional processing speed of the unit to be
controlled, and therefore the unit to be controlled can execute various
kinds of processing with improved functionality. Furthermore, the unit to
be controlled can be used without changing the configuration of its
hardware. Hence, the present invention has various advantages, such as
prolongation of the lifetime of a product, and the like.
FIGS. 6 through 8 show examples in which the present invention is applied
to camera apparatuses.
FIG. 6 is a block diagram showing the configuration of the principal part
of a camera apparatus as a first application illustrating the present
invention.
In FIG. 6, an image pickup unit 600 which serves as a unit to be controlled
has the following configuration. That is, a lens unit 601 includes an
optical system for forming an image of an object, a diaphragm drive,
serving as an exposure control means, a zooming function, and the like.
Reference numeral 602 represents a shutter. A driver circuit 603 drives
the shutter 602. A sensor 604 serves as an image pickup means, such as a
CCD (charge-coupled device) or the like. A driver 605 drives the sensor
604 and a signal processing circuit 606, and performs the control of
synchronization, and the like. A known encoder circuit 607 forms a Y
(luminance) signal and a C (color) signal from a Y signal and R-Y and B-Y
(color-difference) signals output from the signal processing circuit 606.
The Y and C signals output from the encoder circuit 607 are selected by a
switch 608, and converted into a composite video signal by a known decoder
circuit 609. The composite video signal is supplied to an output terminal
610. Y and C signal lines at the output side of the switch 608 (the input
side of the decoder circuit 609) and the composite video signal output
from the decoder circuit 609 are connected to a bus line (not shown) at
the side of the image pickup unit.
A PIO (parallel input/output port) 815 transmits a control signal S2 used
for the control of the image pickup unit 600 by a control unit 620 to the
image pickup unit 600, and is directly connected to the control unit 620
through a bus line.
The control unit 620 has the following configuration. A CPU (central
processing unit) 611 controls the image pickup unit 600. A ROM (read-only
memory) 612 stores operational programs for the CPU 611 and other data. A
RAM (random access memory) 613, for example, temporarily stores data as a
work memory. An SIO (serial input/output port) 614 is used for the
input/output of serial data from a remote control (not shown) or the like
by the CPU 611. In a bus S1 at the side of the control unit, are each of
an address bus and a data bus comprise 32 bits. The bus S1 further
includes lines for power and various kinds of control signals, such as
memory control signals, DMA (direct memory access) control signals,
signals to control interrupt of the CPU, system clock signals and the
like. By connecting the image pickup unit 600 to the control unit 620 by a
connection unit (not shown), the control unit 620 is directly connected to
the bus at the side of the image pickup unit so that the CPU 611 can
control the image pickup unit 600. In the present example, the control
unit 620 is configured as a CPU card having a one-chip microcomputer.
FIG. 7 is a block diagram showing the configuration of the principal part
of a camera apparatus as a second application illustrating the present
invention.
In FIG. 7, reference numerals 600 and 610 indicate the image pickup unit
and the output terminal for composite video signals shown in the first
application, respectively. A control unit 700 in the second application
includes a luminance-signal processing unit 701 for performing various
kinds of signal processing, such as removal of noise, and the like, for
the Y signal supplied from the image pickup unit 600 via the bus line, and
a color-signal scan conversion circuit 702 for performing scan conversion
of the C signal supplied from the image pickup unit 600. The Y signal
output from the luminance-signal processing unit 701 and the C signal
output from the color-signal scan conversion circuit 702 are subjected to
frequency multiplexing and frequency modulation by a signal multiplexing
circuit 703. The resultant signal is recorded on a magnetic tape by a
magnetic tape recording/reproducing unit 705 after being amplified by a
recording amplifier 704. When reproducing a signal recorded on the
magnetic tape by the magnetic tape recording/reproducing unit 705, the
signal read by the magnetic head of the magnetic tape
recording/reproducing unit 705 is subjected to frequency demodulation by a
LPF/HPF (low-pass filter/high-pass filter) circuit 709 after being
amplified by a preamplifier 708, and the low-pass filter output and the
high-pass filter output are taken out as a C signal and a Y signal,
respectively. The Y signal taken out from the LPF/HPF circuit 709 is
subjected to various kinds of signal processing by a luminance-signal
processing circuit 710, and the resultant signal is input to a switch 712.
The C signal taken out from the LPF/HPF circuit 709 is subjected to scan
conversion to a signal having a frequency of 3.58 MHz (megahertz)
corresponding to the band for the normal video color signal by a
color-signal frequency conversion circuit 711, and the resultant signal is
input to a switch 713.
When the magnetic tape recording/reproducing unit 705 performs a
reproducing operation, the switches 712 and 713 are placed in an on-state
by the control of a control circuit 707. Hence, the Y and C signals output
from the luminance-signal processing circuit 710 and the color-signal
frequency conversion circuit 711, respectively, are supplied to the image
pickup unit 600. At that time, the switch 608 is placed in an off-state by
a control signal from the control circuit 707 supplied through the bus
line to the image pickup unit 600. Hence, the Y and C signals supplied
from the control unit 700 to the image pickup unit 600 are converted into
a composite video signal by the decoder circuit 609, and the composite
video signal is output from the output terminal 610. The composite video
signal output from the decoder circuit 609 is supplied to the control unit
700 connected by the bus line, and is input to an EVF (electric view
finder) 714, in which a picture reproduced from the magnetic tape can be
confirmed.
When the magnetic tape recording/reproducing unit 705 performs a recording
operation, the switch 608 is kept to be in an on-state by the control
circuit 707, whereby the Y and C signals are supplied from the image
pickup unit 600 to the control unit 700. At that time, the switches 712
and 713 are kept in an off-state, and the components 701 through 705 for
magnetic recording function, whereby a recording operation is performed by
the magnetic tape recording/reproducing unit 705. Since image data
obtained by the sensor 604 of the image pickup unit 600 is supplied from
the decoder 609 to the EVF 714, an image being photographed can be
confirmed in the EVF 714.
In the present example, the driver 605 within the image pickup unit 600
changes the drive for the signal processing circuit 606 so as to perform
signal processing suitable for magnetic recording conversion processing by
a control signal from the control circuit 707. The recording/reproducing
processing in the magnetic tape recording/reproducing unit 705 and the
control of an operation/display unit (not shown) are, of course, performed
by the control circuit 707.
FIG. 8 is a block diagram showing the configuration of the principal part
of a camera apparatus as a third application illustrative of the present
invention.
In FIG. 8, reference numerals 600 and 610 indicate an image pickup unit and
an output terminal having the same configuration as those shown in the
first and second applications, respectively. Reference numeral 800
represents a control unit in the third illustrative application. The
control unit 800 includes a universal-head unit, comprising mechanical
units, for vertically and horizontally moving the image pickup unit 600.
The universal-head unit 801 includes various kinds of sensors so that its
positional information and the like can be read by a control circuit 803.
A universal-head driving unit 802 serves as a power source for driving the
universal-head unit 801 under the control of the control circuit 803. The
control circuit 803 can perform ganged control of the drive of the
universal-head unit 801, and operations, such as zooming, autofocusing and
the like, of the image pickup unit 600 that is directly connected to the
control circuit 803 by a bus line according to a signal from a remote
control or an operation panel (not shown). Hence, such a camera apparatus
can, for example, be used as a camera unit for a TV (television)
conference.
If control programs stored in the control circuit 803 are used for
controlling a monitoring camera so that the detection of movement in
images (more specifically, using a difference between Y signals in
adjacent frames), the drive of the universal-head unit 801 ganged with
that movement, and the control of zooming are automatically performed.
Accordingly, the above-described camera apparatus can be used as a
monitoring-camera unit.
As explained above, in each of the above-described camera apparatuses, the
image pickup unit, serving as the unit to be controlled, and the control
unit for controlling the unit to be controlled are configured so as to be
detachable at the bus line, and the control unit is configured in
accordance with the function of each apparatus. If, for example, the
control unit is provided with the function of an 8-mm video deck, an 8-mm
video camera is obtained by connecting the image pickup unit, serving as
the unit to be controlled, to the control unit. If the control unit is
provided with the function of a universal head for a monitoring camera, a
monitoring camera provided with a universal head is obtained by connecting
the image pickup unit to the control unit. Accordingly, it is possible
that an image pickup unit may be utilized in many product configurations
which could not previously been utilized because its function in a product
differs. Moreover, by exchanging only the control unit, the combined
apparatus can be utilized as an apparatus providing a different function.
FIGS. 9 through 11 show examples in which the present invention is applied
to transmission apparatuses. FIG. 9 is a block diagram showing a fourth
application illustrative of the present invention.
In FIG. 9, a communication basic unit 900, serving as a unit to be
controlled, has the following configuration. That is, a telephone line is
connected to a network control circuit 901. The network control circuit
901 performs network control in calling and reception operations, and
usually comprises discrete circuitry. A hook circuit 902 sets a telephone
set to an on-hook state or an off-hook state. A dialing circuit 903 forms
dial pulses to be transmitted to the telephone line when the hook circuit
902 provides an off-hook state. A microphone 904 converts a voice signal
into an electrical signal to be transmitted from the network control
circuit 901. On the other hand, a speaker 905 converts an electrical
signal reaching the network control circuit 901 into a voice signal. The
PIO 906 receives a control signal from a control unit 920.
The communication basic unit 900 is detachably connected relative to the
control unit 920 by a bus line. The communication basic unit 900 itself
functions as a simple telephone set. By being connected to the control
unit 920, the communication basic unit 900 functions as a multifunctional
telephone. The control unit 920 comprises a CPU 910 for controlling the
entire telephone set, a ROM 911 for storing programs for the control
performed by the CPU 910 and other data, a RAM 912, serving as a memory
for temporarily storing data used for the control by the CPU 910, an
EEPROM (electrically erasable/programmable read-only memory) 913 capable
of storing information, such as telephone numbers and the like, without
using a backup power supply, an operation/display unit 914 for performing
various kinds of operations instructed by the operator as well as
displaying operational states of the apparatus, and a bus line S3 at the
control side for connecting the above-described components. In the present
example, in the bus line S3 at the control side, an address bus and a data
bus have 32 bits. The bus line S3 also includes lines for powe | | |
