Facsimile and static presentation processing – Static presentation processing – Communication
Reexamination Certificate
1998-07-16
2001-07-31
Mancuso, Joseph (Department: 2624)
Facsimile and static presentation processing
Static presentation processing
Communication
C358S001140, C358S001130
Reexamination Certificate
active
06268928
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a printer having two or more interfaces, and more particularly to a printer connected to an external host device having a plurality of peripheral devices.
2. Description of the Related Art
In department stores, supermarkets, hotels and the like, POS (point of sale) systems for sales management are installed at cash counters where goods and cash are handled and settled. A POS system usually includes one host device, and a plurality of peripheral devices connected thereto, such as a printer, a bar-code reader and a magnetic card reader.
A recent trend has been toward increased types of peripheral devices to cope with diversified data input and data output methods for handling product codes and credit numbers. This requires an increase in the number of interface terminals mounted in the host device.
FIG. 6
is a block diagram showing one example of conventional POS systems. One of a variety of commercially available personal computers is often used as a host device H in order to save cost. The personal computer usually has one or two serial ports, and one parallel port. Thus, a maximum of three peripheral devices, i. e. devices Q
1
and Q
2
and a printer P, may be connected to the host device H. The host device H lacks a connection port for connecting a fourth peripheral device Q
3
or more peripheral devices.
For connecting more peripheral devices than the number of ports of the host device H, an expansion board must be added to the host devices H to provide an increased number of ports. However, not only the cost of the expansion board itself, but a complex control program is required for controlling the expansion board. This results in an increase in the cost and an extended period for development of the entire POS system.
A scanner/printer connectable to a computer is known, in which an optical scanner and a printer are integrated to provide a fax function and a copying mechanism. However, this is a stand-alone type with a particular scanner mounted in a printer, and has no expandability for connecting other peripheral devices.
Japanese Unexamined Patent Publication JP-A8-123640 (1996) describes a connection switch mechanism provided between a host device having only one interface and a plurality of printing devices, for distributing signals by switch circuits on signal lines. This mechanism requires a complicated and costly switching circuit for switching a data bus and a control bus having a plurality of signal lines. Moreover, the mechanism is applicable only to parallel communication based on a busy signal.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a printer for enabling connection of a larger number of devices than the number of connection ports of an external host device.
The invention provides a printer comprising:
a first interface for exchanging signals with an external host device;
a second interface for exchanging signals with a peripheral device;
a printing station for printing a recording medium based on print data supplied by the external host device; and
a signal processing circuit for performing an output through operation to transmit data received from the external host device via the first interface, to the peripheral device via the second interface, and an input through operation to transmit data received from the peripheral device via the second interface, to the external host device via the first interface.
According to the invention, data received from the external host device may be transmitted to the peripheral device in the output through operation. Data received from the peripheral device may be transmitted to the external host device in the input through operation. Thus, data communication between the external host device and peripheral device, and data communication between the external host device and printer, may be effected via the first interface. Only one interface connection port is adequate for the external host device. It is therefore possible to connect a larger number of peripheral devices(including a printer) than the number of connection ports of the external host device.
In the invention, it is preferable that a first protocol of the first interface and a second protocol of the second interface are different from each other.
According to the invention, the first protocol is converted to the second protocol for the output through operation and the second protocol is converted to the first protocol for the input through operation. Thus, data communication may be effected between the external host device and peripheral device even where the protocol with the external host device and the protocol with the peripheral device are different from each other. A protocol means a condition for uniquely defining a command system, communicating conditions (communication rate, data length, parity and so on), type of interface (serial communication, parallel communication, Ethernet or the like), and a communications protocol (DTR mode, Xon/Xoff mode, STX-ETX mode, network protocol or the like).
With the protocol conversion effected by the printer, the external host device may be operable on only one protocol in realizing data communication with a plurality of devices (including the printer) having varied protocols. This reduces the load of the external host device. Moreover, data communication can be made with peripheral devices having protocols with which the external host device cannot cope, resulting in high expandability of peripheral interfaces.
In the invention, it is preferable that the first protocol and the second protocol conform to a serial interface standard.
According to the invention, the protocol conversion between the external host device and various peripheral devices becomes more effective since a serial interface standard requires setting of various conditions such as number of signal lines, synchronous or asynchronous, baud rate, data length, with or without a parity bit, odd number parity or even number parity, stop bit length, flow control method and so on.
REFERENCES:
patent: 5113494 (1992-05-01), Menendez et al.
patent: 5390031 (1995-02-01), Kang et al.
patent: 5528765 (1996-06-01), Milligan
patent: 5696600 (1997-12-01), Perkins
patent: 5953340 (1999-09-01), Scott et al.
patent: 6047319 (2000-04-01), Olson
patent: 0 654 767 (1995-05-01), None
patent: 8-123640 (1996-05-01), None
Mancuso Joseph
Star Micronics Co. Ltd.
Tran Douglas
Wenderoth , Lind & Ponack, L.L.P.
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