This application is based on an application No. H10-327648 filed in Japan, the contents of which are hereby incorporated by reference.
1. Field of the Invention
This invention relates to a composite communication apparatus having a facsimile transmission unit and an electronic mail transmission unit, and relates to a technique to transmit the image data without reduction of the system efficiency in a network system to which the composite communication apparatus is connected.
2. Description of the Related Arts
A communication line is usually provided to connect business machines such as computers in business establishments and branches in an area. Mostly a communication line is owned by a company. The communication system installed in a relatively narrow area as described herein above is referred to as LAN (Local Area Network). LAN of respective business establishments are connected to each other by mean of a network line provided by a communications business vendor to set up a larger network.
To LAN as described herein above, computers and other terminal units can be connected. The composite communication apparatus having a facsimile transmission unit and an electronic mail transmission unit has been known as one of these terminal units.
A composite communication apparatus has two input/output terminals, and respective input/output terminals are connected to LAN and telephone line. A user can select the electronic mail transmission unit or the facsimile transmission unit for use.
When the electronic mail transmission unit is used, the data is transmitted in the format of electronic mail data to other terminal units connected to this LAN or other LAN through the network line.
When an facsimile transmission unit is used, the data is transmitted in the format of facsimile data to a receiver through a telephone line.
The use of a network line is advantageous in that communication cost is low particularly for transmission to a remote location in comparison with the use of a facsimile transmission unit.
On the other hand, the network line is disadvantageous in that information capacity namely the amount of information to be processed in a unit time is limited to an certain value.
Therefore, when a lot of information (electronic mail) is transmitted from a certain business establishment to another business establishment through a network line, the speed of other communications which use the network line could be slowed down to cause a problem on the whole system.
In the electronic mail transmission, though the information to be communicated is basically the character information (text format), the image information can be also transmitted in the form of attachment file when the image information is wanted to be transmitted.
The data size of the character information is not so large even though the number of characters is large. However, the data size of the image data is large even though the number of pages of the image data is not many.
When an image information is transmitted by means of electronic mail, it occurs easily that the user sends extremely voluminous information without recognition.
Therefore, transmission of image data by means of electronic mail involves reduction of the efficiency of the whole system.
It is an object of the present invention to prevent easy transmission of the image data having a large size by means of electronic mail in the use of composite communication apparatus having a facsimile transmission unit and an electronic mail transmission unit.
It is another object of the present invention to prevent the reduction of a system efficiency by preventing easy transmission of the image data of a large size by means of electronic mail in the use of composite communication apparatus having a facsimile transmission unit and an electronic mail transmission unit.
It is yet another object of the present invention to provide a composite communication apparatus having a facsimile transmission unit and an electronic mail transmission unit which switches so that the facsimile transmission unit is used when the image data size is larger than a reference value and the electronic mail transmission unit is used when the image data size is smaller than the reference value.
Thereby, communication expense is reduced without reduction of the system efficiency.
To solve the above-mentioned problem, a composite communication apparatus of the present invention is provided with a facsimile transmission unit for transmitting the image data as a facsimile data, an electronic mail transmission unit for transmitting the image data as an electronic mail data, an operation unit for specifying an addressee to whom the image data is transmitted by use of a facsimile transmission unit or an addressee to whom the image data is transmitted by use of an electronic mail transmission unit, and a controller.
The controller compares the size of the image data to be transmitted with a reference value, and the image data is transmitted by use of the facsimile transmission unit if the size of the image data exceeds the reference value, and on the other hand the image data is transmitted by use of the electronic mail transmission unit if the size of the image data does not exceed the reference value.
Other objects and advantages besides those discussed above shall be apparent to those skilled in the art from the description of a preferred embodiments of the invention which follows. In the description, reference is made to accompanying drawings, which form a part thereof, and which illustrate an embodiment of the invention. Such embodiment, however, is not exhaustive of various embodiments of the invention, and therefore reference is made to the claims which follow the description for determining the scope of the invention.