Image display apparatus having a communication function

An image display apparatus has a communication function which includes an image display for displaying image data and a communication unit for communicating image data and control information with another station. The apparatus includes a controller for controlling the communication unit such that it sends image data displayed on the image display to the other station in response to predetermined control information from the other station.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an image display apparatus having a 
communication function. 
2. Background 
One conventional image display apparatus is disclosed in the Japanese Laid 
Open Patent Specification Sho 63(1988)-18384, which corresponds to the 
U.S. Pat. No. 4,788,564, issued Nov. 29, 1988. 
This conventional display apparatus is explained briefly as follows, 
referring to FIG. 5. 
This apparatus 108 has a display belt 109, on which an image is formed, 
which is endless and whose surface is white. The display belt 109 is 
supported by a pair of rollers 110 and 111 disposed vertically such that 
the belt 109 is able to move parallel to a display part 112. An image 
forming part 113 is also provided to form images on the belt 109 
electrostatically with conductive magnetic toner by using a method, for 
example, as disclosed in U.S. Pat. No. 3,194,771, which discloses how to 
form an image with conductive magnetic toner. The magnetic toner T is 
transported to a recording electrode 116 on a surface of a non magnetic 
cylinder 115 in response to rotation of a rotating magnet 114. The 
recording electrode 116 is driven by a driving device 118 driven in turn 
by a display image signal from an image input device 117. When the driving 
device 118 applies a predetermined voltage, then the magnetic toner T is 
attached to the display belt 109 and thereby the image is formed. 
The above-mentioned image display apparatus is operated by an operator who 
supplies image data to be displayed by controlling an image reader, a 
personal computer, or the like. Therefore, an operator must be near by the 
display apparatus. 
The present inventors have considered how an operator can send image data 
via a facsimile communication line from a distant place to the display 
apparatus to display image data. Such a facsimile apparatus is disclosed 
in Japanese Laid Open Publication Sho54 (1979)-53915. An operator, 
however, who has sent image data in this way cannot confirm which image 
data is displayed, nor discriminate whether displayed image data should be 
erased or replaced or not. 
Therefore, it is preferable that a distant operator be able to recognize 
which image is displayed on the display apparatus without a special 
apparatus. 
Further, in the case where the apparatus can display an image from a 
distant station by using any method, any of the operators can change the 
displayed image innocently or mischievously unless the operator is 
limited. Therefore, it is preferable to avoid such mischief. 
In the case where an operator wants to change an image to be displayed, it 
is also a problem if the operator has to order from the remote location 
every time. 
SUMMARY OF THE INVENTION 
A purpose of the present invention is to provide a novel image display 
apparatus having a communication function which overcomes the above 
mentioned shortcomings. 
One aspect of the present invention is to provide an image display 
apparatus having a communication function, which includes an image display 
for displaying image data, means for communicating image data and control 
information with another station, and means for controlling the 
communicating means such that the communicating means sends image data 
displayed on the image display to the other station in response to a 
predetermined kind of control information from the other station. Thereby, 
an operator at the distant other station can confirm the image data 
displayed on the image display. 
Another aspect of the present invention is to provide an image display 
apparatus which includes means for communicating image data and control 
information including an identification signal, an image display for 
displaying image data received by the communication means, and means for 
controlling whether the communicating means permits reception of the image 
data in response whether the received identification signal is correct or 
not. Thereby, anyone who does not know the identification signal can be 
prohibited from displaying any image data through mischief. 
Another aspect of the present invention is to provide an image display 
apparatus having a communication function, which includes a memory for 
storing image data, an image display for displaying image data stored in 
the memory, means for communicating control information with another 
station, and means for changing image data displayed on the image display 
to other image data stored in the memory in response to a predetermined 
kind of control information received by the communicating means. Thereby, 
an operator at the distant station can easily change image data displayed 
on the image display to new image data. 
Another aspect of the present invention is to provide an image display 
apparatus having a communication function, which includes an image display 
for displaying image data, means for communicating image data and control 
information and having a polling function sending image data displayed on 
the image display in response to a polling request from another station, 
and means for controlling the communicating means such that when an 
identification signal from the another station is correct, said 
communicating means sends the image data displayed on said image display 
in response to the polling request without using a non standard procedure 
of the Group 3 facsimile apparatus. Thereby, an operator at the distant 
station can confirm the image data displayed on the image display without 
special receiving apparatus. 
However, in the case that the above mentioned display apparatus is used for 
an unattended advertising display, if the display apparatus has a 
malfunction, an operator at the distant station cannot recognize the 
malfunction, so that the operator may request a change in image data or 
send image data to be displayed without recognizing the malfunction. 
Therefore, the unattended display apparatus is not used effectively. 
Therefore, another purpose of the present invention is to provide an image 
display apparatus having a communication function, which includes means 
for communicating image data and control information with another station, 
an image display for displaying image data, means for detecting an 
operating condition of the image display, and means for controlling the 
communicating means such that it sends image data displayed on the image 
display and the operating condition detected by said detecting means. 
Thereby, an operator at the distant station can easily confirm not only 
the image data displayed on the display but the operating condition of the 
display. 
The foregoing summary of certain advantageous features of the invention is 
provided in order that the detailed description of the embodiments thereof 
that follows may be better understood, and in order that the present 
contribution to the art may be better appreciated. There are, of course, 
additional features of the invention that will be described in that 
detailed description with reference to the accompanying drawing. Those 
skilled in the art will appreciate that the conception upon which this 
disclosure is based may readily be utilized as a basis for designing other 
structures or methods for carrying out the purposes of the invention. It 
will be understood that the claims are to be regarded as including such 
other constructions and methods as do not depart from the spirit and scope 
of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows a block diagram of an image display apparatus having a 
communication function. 
The display apparatus includes an operation and display unit 100, a memory 
unit 102 for storing image data to be displayed and information for 
display control. The memory unit 102 can store image data corresponding to 
a plurality of pages. A screen display unit 103 is also provided for 
displaying images, and the unit 103 is structured as shown in FIG. 5. The 
apparatus also includes a communication unit 104 for receiving image data 
from a communication line 105 and for transmitting image data stored in 
the memory unit 102 to outside apparatus via the line 105, and the 
communication unit 104 is structured by a conventional facsimile 
apparatus. The memory unit 102 stores image data received from the line 
105 in a compressed and coded condition. The line 105 can be a general 
public line, an excluding line, or the like. The apparatus also has a 
controller 101 for controlling the entire apparatus, an image input device 
106, e.g. an image reader, for inputting image data and a ROM (Read Only 
Memory) 107 for storing a control program of the controller 101 as shown 
in FIGS. 2 and 3. 
Referring to the flowchart of FIG. 2, an operation of the display apparatus 
will be explained as follows. 
First of all, when a calling facsimile apparatus calls this apparatus via 
the line 105 to establish a call (S1), this apparatus sends a secret 
identification request signal (S2). 
Unless a secret identification number is received within five seconds, the 
controller 101 disconnects the line and ends the communication in steps 
S2, S3 and S18. 
On the other hand, if the secret identification number is received within 
five seconds of the request signal (S3, S4), the controller 101 
discriminates whether the identification number is correct or not (S5). If 
it is not correct, the controller 101 sends the request signal again in 
step S2. 
If the identification number is not correct again, the controller 101 
disconnects the line and ends communication in steps S6 and S18. 
Thereby, this display apparatus accepts a call only from a specified 
distant station which knows the secret identification number to avoid 
mischievous interference by unauthorized distant stations. 
If the identification number is correct, the controller 101 waits for a 
remote command having DTMF (Dual Tone Multi Frequency) signals for two 
seconds in steps S7 and S8. When the remote command is not received in two 
seconds, the controller 101 discriminates that the other apparatus is in a 
image data transmission mode, and sends a transmission request having a 
"bleep" sound for requesting image transmission (S9). In step S10, this 
apparatus enters an image reception mode, and receives image data from the 
calling apparatus by the communication unit 104 while checking for errors 
in received image data. The received image data is transferred and stored 
into the memory unit 102 in step S11, and simultaneously is transferred to 
the screen display unit 103 to display one page of the receiving image 
data in step S14. Then the controller 101 disconnects the line and ends 
communication in step S18. 
If the memory unit 102 cannot store all the received image data, the 
controller 101 sends an error signal to the calling station in steps S12 
and S13. 
When the remote command is received, the controller 101 analyzes the remote 
command. If the received remote command is discriminated as a display 
change command in step S15, the controller 101 causes the memory unit 102 
to read out image data for the next page, and transfers the read image 
data to the screen display unit 103 in step S16. The display unit 103 
changes the display to the next p age in step S17, and the controller 101 
disconnects the line and ends communication in step S18. 
If the received remote command is discriminated as a polling request 
command for confirming the display image which is now displayed in step 
S19, the controller 101 reads out all t he image data in the memory unit 
102 from the data which is now displayed on the screen display unit 103 in 
step S20, and causes the communication unit 104 to send the read image 
data to the calling station via the communication line 105 in step S21. 
Then the controller 101 disconnects the line 105 and ends communication in 
step S18 as well. 
Thus, the calling station can request this station to send the image data 
by the DTMF polling request command without using the non standard 
procedure of T30 of CCITT recommendation. Generally, the non standard 
procedure is different among manufacturers. But, in this case, a calling 
station which is made by another manufacturer is able to send a polling 
request if an operator knows the identification number. That is, checking 
the secret identification number in step 55 is a substitute for checking a 
polling ID for the polling operation defined in T30, so that this station 
can shift to the image transmission mode without carrying out the non 
standard procedure of T30. 
Thereby, an operator of the distant calling station can confirm the image 
data displayed on the screen display unit 3 by receiving the image data 
with its own facsimile apparatus. 
The controller 101 controls the starting address of the image data which is 
currently displayed, so that in the polling operation the controller can 
send the image data currently displayed first. Therefore, an operator at 
the distant calling station can recognize quickly which image data is 
currently displayed among plural pages of image data. 
If the controller 101 discriminates that the remote command is an automatic 
image change command in step S22, the controller 101 starts an internal 
timer in step S23, and stores data showing interval time for display, 
which is received with a DTMF signal as well as the remote command, into 
the memory unit 102 in step S24. Then the controller 101 disconnects the 
line 105 in step S25. The controller 101 compares the interval time with a 
count value of the internal timer in step S26, and if they coincide, the 
controller 101 reads out the next image data from the memory unit 102 and 
causes the display unit 103 to display the next image data in steps S27 
and S28. Then the internal timer is reset and restarted in step S29. 
Thus, the image data stored in the memory unit 102 is displayed cyclically 
with a predetermined interval. 
When the controller 101 discriminates that the received remote command is 
another kind of command, the controller 101 carries out a procedure in 
response to that command in step S30, and disconnects the line 105. 
FIG. 3 shows a detailed flowchart illustrating retrieval of the secret 
identification number in FIG. 2. 
Referring to FIG. 3, the controller 101 has internal registers PASSWORD, 
IDRQMD, NUMBER, A and C. The secret identification number is set by 
switches on the operation and display unit 100 and is stored in the 
register PASSWORD. In this embodiment, if the predetermined secret 
identification number is set by an operator, the apparatus can be designed 
such that the controller 101 does not retrieve the identification number, 
or such that the controller 101 allows the image reception without 
limitation by any identification numbers entered from a calling station. 
For example, if "0" is set in the register PASSWORD, the controller 101 
does not retrieve the secret identification number, and if "9999" is set 
in the register PASSWORD, the controller 101 allows the image reception by 
any identification number entered from a calling station. 
When a call is received from a calling station and "0" is set in the 
register PASSWORD, the controller 101 does not send the secret 
identification request signal to the calling facsimile station, and 
enables reception of image data or other communication in steps S51 and 
S60. 
If the register PASSWORD stores a number other than "0", the controller 
sends the secret identification request signal in step S53. When the 
secret identification number is received from the calling station, the 
received number is stored into the register A in steps S54 and S55. 
When the register PASSWORD stores "9999", the controller 101 starts the 
image reception mode or other communication modes regardless of whether 
any identification number is received in step S60. 
Further, in this embodiment, this apparatus can send various kinds of 
secret identification request signals to a calling facsimile station, 
i.e., a chime signal, a DTMF signal and a voice signal. One of them is 
selected by the value of the register IDRQMD, which is set by switches on 
the operation and display unit 100. If "0" is set in the register IDRQMD, 
the controller 101 selects the chime signal as the request signal. If "1" 
is set the controller 101 selects the DTMM signal, and if "2" is set the 
human voice signal is selected. The chime signal and the human voice are 
stored in the memory unit 102 as voice data, and they are sent via the 
communication unit 103 and the line 105 to the calling facsimile apparatus 
or telephone set. 
If the register PASSWORD stores other than "9999" or "0", the controller 
101 discriminates whether the received number is coincident with the 
number stored in the register PASSWORD. If it is, the controller 101 
allows the image reception, but if not the controller 101 decrements the 
value stored in the register C in step S58. Then the controller 101 
discriminates whether the value of the register C is "0" or not in step 
S59. In step S52, the controller 101 loads a value of the register NUMBER 
storing maximum permissible number of errors in entering the secret 
identification number to the register C. 
If the value of the register C becomes "0", the controller 101 
discriminates that the operator at the calling station does not know the 
secret identification number, and disconnects the line. If not, the 
controller 101 sends the request signal again. 
FIG. 4 illustrates a program of a calling facsimile apparatus. 
When the calling station receives the secret identification number request 
signal in step S71, the calling station discriminates whether the calling 
station is set in an automatic transmission mode in step S72. If it is, 
the calling station reads out a prestored secret identification number and 
sends that number to the image display apparatus in step S73. 
On the other hand, if the calling station is set in a manual transmission 
mode, the calling station waits for the identification number to be 
entered by an operator in step S78. Upon entry of the identification 
number the calling station sends the number to the image display apparatus 
in step S79. 
When the calling station receives the transmission request from the display 
apparatus in step S74, the calling station sends image data to be 
displayed automatically in step S76 under the automatic transmission mode, 
and sends the image data on actuation of a transmission start key by the 
operator in step S80 under the manual transmission mode. 
Another embodiment of the present invention which is applied to an 
unattended advertising display is explained as follows. 
FIG. 6 shows a block diagram of the second embodiment wherein the elements 
having same functions as in FIG. 1 have same identification numbers. In 
FIG. 6, a controller 101' controls the entire display apparatus, a data 
adding unit 115 writes operating condition data of the display apparatus 
into the memory unit 102, and a ROM 107' stores a control program of the 
controller 101' as shown in FIG. 7. A self diagnosis unit 120 is also 
provided for diagnosing the screen display unit 103 and for detecting an 
abnormal part. 
It will be explained how the apparatus works referring to FIG. 7. In FIG. 
7, the steps having the same operations in FIG. 2 have same step numbers, 
and their explanations are omitted. 
The operations in FIG. 7 different from those of FIG. 2 are operations when 
the remote command is a polling request command for confirming the image 
which now is displayed on the screen. 
When the remote command is discriminated as the polling request command in 
step S19, the controller 101' reads out image signal corresponding to the 
image displayed on the screen display 103 in step S20-3. Simultaneously, 
the controller 101' receives the operating condition data from the self 
diagnosis unit 120, and sends the data to the data adding unit 115. The 
data adding unit 115 converts the received condition data to image data 
and adds the converted image data at the top of the read out image data 
from the memory unit 102 in step S20-2. 
Then, the controller 101' sends the image data of the operating condition 
data and the displayed image data to the line 105 via the communication 
unit 104 while reading out the image data from the memory unit in step 
S21. After sending all the image data, the controller 101' disconnects the 
line and ends communication in step S18. If the screen display unit 103 
does not display any image, the controller 101 sends only the image data 
of the operating condition. 
FIG. 8(1) illustrates an example of the image data of the operating 
condition to be added on the image data. In this case, there is a mark at 
number 4, and this indicates that the display apparatus has a malfunction 
on a developing motor. FIG. 8(2) shows contents of malfunctions 
corresponding to numbers. 
The self diagnosis unit 120 detects the operating condition of the screen 
display unit every predetermined period, e.g., three seconds. 
Thus, as described above, an operator at the distant facsimile apparatus 
can receive the image data which is displayed on the screen display at 
that time and the operating condition of the display apparatus by a 
polling request. The image data of the operating condition is recorded on 
the top of a recording paper at the receiving side. 
As well as in the first embodiment, the controller 101' administrates 
addresses of all the pages of the image data stored in the memory unit 
102, so that the controller 101' can read out all the pages of the image 
data after reading out the image data displayed on the screen display 103 
at the time of polling operation. The controller 101' sends all the pages 
of the image data with page numbers, and the operator at the receiving 
side can know all the pages of the image data stored in the memory unit 
102. 
In this embodiment, the operating condition data is converted to image data 
and the converted image data is sent. However, the operating condition 
data can be sent in code format and the calling station can convert the 
code format to image data. 
Instead of the operating condition data being added to the image data read 
out from the memory unit during reading out, the operating condition data 
can be replaced by a part of the image data stored in the memory unit, and 
then the replaced image data and the rest of the image data can be sent. 
The controller 101' detects malfunctions every three seconds in this 
embodiment, but the controller 101' may check for malfunctions every 
desired number of seconds. Alternatively, the controller 101' may check 
only when the polling request is received. 
Further, the operating condition data above is recorded on the top of the 
recording paper, but it can be recorded on any appropriate blank space. 
In the second embodiment as well as in the first embodiment, the display 
apparatus does not use the non standard procedure shown in T-30 of the 
CCITT recommendation, but carries out polling by the DTMF remote command. 
However, the non standard procedure can be used, and an example of 
operating software therefor is shown in FIG. 9. In FIG. 9, the same 
operations as in FIG. 7 have same step numbers, and their explanations are 
omitted. 
As described above, the display apparatus sends not only the image data 
stored in the memory but the operating condition of the called station to 
the calling station when the polling request is received by the calling 
station. Therefore, an operator at the distant calling station is able to 
confirm the operating condition of the calling station as well as the 
image data stored in its memory or displayed on the screen. Thereby, the 
operator at the distant station can deal with malfunctions appropriately. 
For example, if the malfunction is not so serious, such as the door is 
open or the like, the operator can call the user of the display apparatus 
to close the door, and if the malfunction requires fixing, the operator 
can send a repair person. 
Further, in this embodiment, the display apparatus informs the calling 
station that there is no malfunction by marking the number "0" as shown in 
FIG. 8, so that the operator at the distant calling station can easily 
confirm that the apparatus works ordinarily. 
In the above mentioned embodiments, the remote command is sent from the 
facsimile apparatus, but other apparatus which can send a control signal 
like a DTMF signal can be applied to the present invention. 
Further, in these embodiments, the screen display unit which maintains its 
display without power supply is used, but other displays such as a CRT 
display, a liquid crystal display, and the like can be used as the screen 
display. 
Although particular embodiments of the present invention are herein 
disclosed for purposes of explanation, various modifications thereof, 
after study of this specification, will be apparent to those skilled in 
the art to which the invention pertains. 
As described above, according to present invention, an operator at the 
distant station can confirm the image data displayed on the image display, 
and for anyone who does not know the identification signal can be 
prohibited from mischievously displaying image data. 
Further, an operator at the distant station can easily change image data 
displayed on the display to new image data, can confirm the image data 
displayed on the image display without a specially featured receiving 
apparatus, and can easily confirm not only the image but the operating 
condition of the display. Therefore, even though the operator at the 
distant station orders a change in the image data to be displayed, the 
display will not maintain its display of old image data without 
recognizing its malfunction.