Wireless communication device and printing system using the same

• US 5,490,287 A
• Filed: 01/13/1994
• Issued: 02/06/1996
• Est. Priority Date: 04/04/1991
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Itoh, Nobuyasu, Ueda, Shigeru
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): SOBUTKA, PHILIP
• Application Number:
  US08/181,870
• Time in Patent Office: 754 Days
• Field of Search: 455/69, 455/67.1, 455/92, 455/88, 455/115, 455/127, 455/66, 455/57.1, 455/56.1, 178/4.1 A, 358/442, 358/468, 379/58, 379/59, 379/60, 400/62
• US Class Current: 455/41.3
• CPC Class Codes: H04W 52/362 Aspects of the step size
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range

Abstract

In a network of wireless communication devices, each device has a unit for transmitting information, a unit for variably controlling the transmission power for transmission of information, a unit for receiving information transmitted, and a unit for controlling the other units. Each device shifts the transmission power to a level proper to a current receiver device.

Claims

1. An apparatus for transmitting print data generated by a host computer to a plurality of printers by wireless communication comprising:

selecting means for selecting one printer from the plurality of printers;

sending means for transmitting data to the selected printer;

control means for variably controlling a transmission power for said sending means to transmit the print data; and

receiving means for receiving information transmitted from the printer,

wherein said control means comprises memory means for storing a table including data representative of the transmission power corresponding to each printer, and sets said transmission power to the selected printer in accordance with the data representative of the transmission power corresponding to the selected printer in the table,

wherein when said apparatus updates the table, said sending means sends predetermined data, which includes data representative of the transmission power of said predetermined data itself, to the selected printer, so that the selected printer can determine the transmission power for sending status data on the basis of the received data, and

wherein said apparatus comprises judging means for judging whether the status data representative of correct receipt of the predetermined data is received or not by said receiving means, on the basis of the result of judgment of said judging means, updates the data representative of the transmission power corresponding to the selected printer in the table.

2. An apparatus according to claim 1, wherein when the apparatus is turned on, said selecting means selects sequentially the plurality of the printers, and said apparatus updates the data representative of the transmission power corresponding to the selected printer in the table in accordance with the result of judgment by said judging means.

3. An apparatus according to claim 1, wherein said memory means comprises a nonvolatile memory.

4. Apparatus according to claim 1, wherein said apparatus updates the data representative of the transmission power corresponding to the selected printer in said table when the transmitted print data are not correctly received by the selected printer.

5. An apparatus according to claim 4, wherein when the transmitted print data are not correctly received by the selected printer, said apparatus updates the data in accordance with a resend request from the selected printer.

6. An apparatus according to claim 1, wherein said apparatus transmits the print data to the selected printer, said apparatus updates the data representative of the transmission power corresponding to the selected printer in the table in accordance with the result of judgment by said judging means.

7. An apparatus according to claim 6, wherein said apparatus discriminates whether a status of the selected printer is ready or not when said judging means judges that the status data representative of correct receipt of the predetermined data is received, and if the status is not ready, discriminates it once again after a predetermined time.

8. An apparatus according to claim 7, wherein said apparatus sends a predetermined amount of the print data between a start bit and an end bit when the status of the selected printer is discriminated to be ready.

9. An apparatus according to claim 7, further comprising a host computer for generating the print data.

10. An apparatus for receiving print data from a print transmitter by wireless communication for printing by a printer, comprising:

receiving means for receiving the print data and predetermined data, which is transmitted prior to the print data and includes data representative of the transmission power of said predetermined data itself, transmitted by wireless communication;

judging means for judging whether said receiving means has correctly received the predetermined data;

sending means for transmitting status data representative of a judgment made by said judging means to the print transmitter;

control means for variably controlling transmission power of said sending means used for transmitting to the print transmitter,

wherein said control means comprises memory means for storing a table including data representative of the transmission power of said sending means, and rewrites the table according to the data representative of transmission power of the predetermined data.

11. An apparatus according to claim 10, wherein said memory means comprises nonvolatile memory.

12. An apparatus according to claim 10, further comprising converting means for converting the print data including a character code into a dot pattern.

13. An apparatus according to claim 12, further comprising a memory being capable of storing the dot pattern converted by said converting means for one page.

14. An apparatus according to claim 12, further comprising the printer for printing the dot pattern.