Non-impact printer and a print head thereof

• US 5,892,532 A
• Filed: 07/08/1997
• Issued: 04/06/1999
• Est. Priority Date: 07/08/1994
• Status: Expired due to Term

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Nagumo, Akira, Ito, Katsuyuki, Negishi, Koichi, Ida, Koji, Katakura, Shinichi
• Primary Examiner(s): Le, N.
• Assistant Examiner(s): NGUYEN, THINH H
• Application Number:
  US08/889,706
• Time in Patent Office: 637 Days
• Field of Search: 347/240, 347/236, 347/237, 347/238
• US Class Current: 347/240
• CPC Class Codes: B41J 2/45 using light-emitting diode [LED] or laser arrays
• CPC Class Codes: B41J 2202/17 Readable information on the head
• CPC Class Codes: G06K 15/1247 using an array of light sources, e.g. a linear array

Abstract

A print head for non-impact printer is, for example, an LED head which comprises a plurality of light-emitting elements, LED drivers for selectively causing a drive current to flow into the light-emitting elements on the basis of the print data, a non-volatile memory for storing the modification data related to the value of the drive current. The modification data are determined in advance at the manufacturing process on the basis of the measured result when the light-emitting elements were driven by the LED driver so that all the light-emitting elements emit substantially same amount of light at the printing operation.

Claims

1. A print head comprising:

a plurality of light emitting printing elements, each printing element having an input;

a plurality of drivers, each driver having a function of changing drive energy, each driver being coupled to the input of a corresponding printing element, each driver having an input for receiving a print datum thereat and an input for receiving modification data thereat, each driver generating the drive energy if the print datum has a logic for printing and causing the drive energy to flow into the respective printing element, a value of each drive energy being determined based on the received corresponding modification data;

a memory having a plurality of modification data stored therein, each modification data being previously determined based on a measured output intensity of the corresponding printing element when such corresponding printing element is driven by the corresponding driver such that each energy is emitted through an optical system from each printing element at a substantially uniform intensity at the printing operation;

a transmitter for transmitting each modification data stored in the memory to the corresponding driver having the function of changing drive energy prior to the printing operation; and

a mode controller for switching between a printing mode in which said printing operation is conducted and a transmission mode in which each modification data stored in said memory is transmitted to the corresponding driver.

2. A print head comprising a plurality of IC chips, each IC chip having:

a plurality of light emitting printing elements, each printing element having an input;

a plurality of drivers, each driver having a function of changing drive energy, each driver being coupled to the input of a corresponding printing element, each driver having an input for receiving a print datum thereat and an input for receiving modification data thereat, each driver generating the drive energy if the print datum has a logic for printing and causing the drive energy to flow into the respective printing element, a value of each drive energy being determined based on the received corresponding modification data;

a memory having a plurality of modification data stored therein, each modification data being previously determined based on a measured output intensity of the corresponding printing element when such corresponding printing element is driven by the corresponding driver such that each energy is emitted through an optical system from each printing element at a substantially uniform intensity at the printing operation; and

a transmitter for transmitting each modification data stored in the memory to the corresponding driver having the function of changing drive energy prior to the printing operation;

wherein each driver comprises a reference-energy changer for supplying a reference energy to the corresponding driver;

each of said IC chips further having an energy changer to which modification data for said energy changer is supplied and which adjusts the reference energy supplied to said drivers, so that said energy changer adjusts the reference energy of the respective IC chip; and

said reference energy being adjusted on the basis of the corresponding modification data transmitted from said memory.

3. A print head comprising:

a plurality of light emitting printing elements, each printing element having an input;

a plurality of drivers, each driver having a function of changing drive energy, each driver being coupled to the input of a corresponding printing element, each driver having an input for receiving a print datum thereat and an input for receiving modification data thereat, each driver generating the drive energy if the print datum has a logic for printing and causing the drive energy to flow into the respective printing element, a value of each drive energy being determined based on the received corresponding modification data;

a memory having a plurality of modification data stored therein, each modification data being previously determined based on a measured output intensity of the corresponding printing element when such corresponding printing element is driven by the corresponding driver such that each energy is emitted through an optical system from each printing element at a substantially uniform intensity at the printing operation;

a transmitter for transmitting each modification data stored in the memory to the corresponding driver having the function of changing drive energy prior to the printing operation; and

a memory writing controller,

wherein each driver comprises a shift register for storing said print datum or said modification data, and a latch for latching said print datum stored in said shift register; and

wherein each driver comprises a multiple shift registers for storing said modification data transmitted from the corresponding latch according to an instruction from said memory writing controller, and a first circuit for changing said drive energy of the corresponding printing element based on the modification data stored in said multiple shift registers;

said modification data inputted to said multiple shift registers being one-bit data, an energy instruction signal outputted from said multiple shift registers being multi-bit data.

4. A print head comprising:

a plurality of light emitting printing elements, each printing element having an input;

a plurality of drivers, each driver having a function of changing drive energy, each driver being coupled to the input of a corresponding printing element, each driver having an input for receiving a print datum thereat and an input for receiving modification data thereat, each driver generating the drive energy if the print datum has a logic for printing and causing the drive energy to flow into the respective printing element, a value of each drive energy being determined based on the received corresponding modification data;

a memory having a plurality of modification data stored therein, each modification data being previously determined based on a measured output intensity of the corresponding printing element when such corresponding printing element is driven by the corresponding driver such that each energy is emitted through an optical system from each printing element at a substantially uniform intensity at the printing operation;

a transmitter for transmitting each modification data stored in the memory to the corresponding driver having the function of changing drive energy prior to the printing operation; and

wherein a plurality of the drivers and the memory are composed within a single IC chip;

wherein each driver comprises a print datum storage section for storing said print datum inputted through a first data line;

wherein said memory stores said modification data inputted through a second data line; and

wherein said IC chip further comprises a common external terminal coupled to both said first and second data lines, and a switching section for selecting either said common external terminal or said second data line.

5. A non-impact printer comprising:

a plurality of light emitting printing elements, each printing element having an input;

a plurality of drivers, each driver having a function of changing drive energy, each driver being coupled to the input of a corresponding printing element, each driver having an input for receiving a print datum thereat and an input for receiving modification data thereat, each driver generating the drive energy if the print datum has a logic for printing and causing the drive energy to flow into the respective printing element, a value of each drive energy being determined based on the received corresponding modification data;

a memory having a plurality of modification data stored therein, each modification data being previously determined based on a measured output intensity of the corresponding printing element when such corresponding printing element is driven by the corresponding driver such that each energy is emitted through an optical system from each printing element at a substantially uniform intensity at the printing operation;

a transmitter for transmitting each modification data stored in the memory to the corresponding driver having the function of changing drive energy prior to the printing operation; and

a mode controller for switching between a printing mode in which said printing operation is conducted and a transmission mode in which each modification data stored in said memory is transmitted to the corresponding driver.

6. A non-impact printer comprising:

a plurality of light emitting printing elements, each printing element having an input;

a plurality of drivers, each driver having a function of changing drive energy, each driver being coupled to the input of a corresponding printing element, each driver having an input for receiving a print datum thereat and an input for receiving modification data thereat, each driver generating the drive energy if the print datum has a logic for printing and causing the drive energy to flow into the respective printing element, a value of each drive energy being determined based on the received corresponding modification data;

a memory having a plurality of modification data stored therein, each modification data being previously determined based on a measured output intensity of the corresponding printing element when such corresponding printing element is driven by the corresponding driver such that each energy is emitted through an optical system from each printing element at a substantially uniform intensity at the printing operation;

a transmitter for transmitting each modification data stored in the memory to the corresponding driver having the function of changing drive energy prior to the printing operation; and

a memory writing controller,

wherein each driver comprises a shift register for storing said print datum or said modification data, and a latch for latching said print datum stored in said shift register; and

wherein each driver comprises a multiple shift registers for storing said modification data transmitted from the corresponding latch according to an instruction from said memory writing controller, and a first circuit for changing said drive energy of the corresponding printing element based on the modification data stored in said multiple shift registers;

said modification data inputted to said multiple shift registers being one-bit data, an energy instruction signal outputted from said multiple shift registers being multi-bit data.

7. A print head comprising:

a plurality of light emitting printing elements, each printing element having an input;

a plurality of drivers, each driver having a function of changing drive energy, each driver being coupled to the input of a corresponding printing element, each driver having an input for receiving a print datum thereat and an input for receiving modification data thereat, each driver generating the drive energy if the print datum has a logic for printing and causing the drive energy to flow into the respective printing element, a value of each drive energy being determined based on the received corresponding modification data;

a non-volatile memory having a plurality of modification data stored therein, each modification data being previously determined based on a measured output intensity of the corresponding printing element when such corresponding printing element is driven by the corresponding driver such that each energy is emitted through an optical system from each printing element at a substantially uniform intensity at the printing operation;

a transmitter for transmitting each modification data stored in the memory to the corresponding driver having the function of changing drive energy prior to the printing operation; and

wherein the memory and the transmitter are provided within a first IC chip, and the driver is provided within a second IC chip different from the first IC chip.

8. A print head comprising:

a plurality of light emitting printing elements, each printing element having an input;

a plurality of drivers, each driver having a function of changing drive energy, each driver being coupled to the input of a corresponding printing element, each driver having an input for receiving a print datum thereat and an input for receiving modification data thereat, each driver generating the drive energy if the print datum has a logic for printing and causing the drive energy to flow into the respective printing element, a value of each drive energy being determined based on the received corresponding modification data;

a memory having a plurality of modification data stored therein, each modification data being previously determined based on a measured output intensity of the corresponding printing element when such corresponding printing element is driven by the corresponding driver such that each energy is emitted through an optical system from each printing element at a substantially uniform intensity at the printing operation; and

a transmitter for transmitting each modification data stored in the memory to the corresponding driver having the function of changing drive energy prior to the printing operation;

wherein the transmitter is composed so as to transmit a predetermined number of transmission data, the predetermined number being equal to or more than a number of the data stored in the memory regardless of the number of the data stored in the memory;

if the number of data stored in the memory is less than the predetermined number of transmission data, the data is stored in the memory so as to be transmitted with a delay corresponding to a difference between the predetermined number of transmission data and the number of the data stored in the memory, thereby setting the data stored in the memory in the driver at a same time as completing transmitting the predetermined number of transmission data.

9. A non-impact printer comprising:

a plurality of light emitting printing elements, each printing element having an input;

a plurality of drivers, each driver having a function of changing drive energy, each driver being coupled to the input of a corresponding printing element, each driver having an input for receiving a print datum thereat and an input for receiving modification data thereat, each driver generating the drive energy if the print datum has a logic for printing and causing the drive energy to flow into the respective printing element, a value of each drive energy being determined based on the received corresponding modification data;

a non-volatile memory having a plurality of modification data stored therein, each modification data being previously determined based on a measured output intensity of the corresponding printing element when such corresponding printing element is driven by the corresponding driver such that each energy is emitted through an optical system from each printing element at a substantially uniform intensity at the printing operation; and

a transmitter for transmitting each modification data stored in the memory to the corresponding driver having the function of changing drive energy prior to the printing operation;

wherein the memory and the transmitter are provided within a same IC chip, and the drivers are provided within another IC chip.

10. A non-impact printer comprising:

a plurality of light emitting printing elements, each printing element having an input;

a plurality of drivers, each driver having a function of changing drive energy, each driver being coupled to the input of a corresponding printing element, each driver having an input for receiving a print datum thereat and an input for receiving modification data thereat, each driver generating the drive energy if the print datum has a logic for printing and causing the drive energy to flow into the respective printing element, a value of each drive energy being determined based on the received corresponding modification data;

a memory having a plurality of modification data stored therein, each modification data being previously determined based on a measured output intensity of the corresponding printing element when such corresponding printing element is driven by the corresponding driver such that each energy is emitted through an optical system from each printing element at a substantially uniform intensity at the printing operation; and

a transmitter for transmitting each modification data stored in the memory to the corresponding driver having the function of changing drive energy prior to the printing operation;

wherein the transmitter is composed so as to transmit a predetermined number of transmission data, the predetermined number being equal to or more than a number of the data stored in the memory regardless of the number of the data stored in the memory;

if the predetermined number is less than the number of data stored in the memory, the data is stored in the memory so as to be transmitted with a delay corresponding to a difference between the predetermined number or transmission data and the number of the data stored in the memory, thereby setting the data stored in the memory in the driver after completing transmitting the predetermined number of transmission data.

11. A print head comprising:

a plurality of light emitting printing elements, each printing element having an input;

a plurality of drivers, each driver having a function of changing drive energy, each driver being coupled to the input of a corresponding printing element, each driver having an input for receiving a print datum thereat and an input for receiving modification data thereat, each driver generating the drive energy if the print datum has a logic for printing and causing the drive energy to flow into the respective printing element, a value of each drive energy being determined based on the received corresponding modification data;

a memory having a plurality of modification data stored therein, each modification data being previously determined based on a measured output intensity of the corresponding printing element when such corresponding printing element is driven by the corresponding driver such that each energy is emitted through an optical system from each printing element at a substantially uniform intensity at the printing operation; and

a transmitter for transmitting each modification data stored in the memory to the corresponding driver having the function of changing drive energy prior to the printing operation;

wherein the plurality of drivers are divided into groups including a predetermined number of the drivers, and each group is provided within a single IC chip, the IC chip further comprising an energy changer which adjusts an output energy of the IC chip on the basis of the modification data corresponding to the energy changer supplied from the memory.