JP3300868B2 - Drive IC for print head and print head using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head such as a thermal print head or an LED print head and a drive IC used for the print head.

[0002]

2. Description of the Related Art Among these types of print heads, the structure of a thermal print head is disclosed, for example, in Japanese Patent Laid-Open No. 5-301.
No. 366. On the head substrate, a thin heating resistor extending in the longitudinal direction is formed by printing, and heating dots obtained by dividing the heating resistor into minute lengths are printed by a drive IC which is also mounted on the insulating substrate. It is individually driven to generate heat according to the data. For example, B
In order to print at a print density of 200 dpi with a print width of four sizes, 2048 heating dots are arranged in rows.

The driving IC is responsible for driving a plurality of continuous heating dots. The number of heat-generating dots handled by each drive IC is 3 such as 32, 64, and 96.
Usually, it is a multiple of two. When a drive IC capable of driving 64 heating dots is used, 32 drive ICs are mounted on a head substrate to configure a print head having 2048 heating dots so as to perform B4 size printing. Will be.

On one side of the upper surface of a drive IC for driving 64 heating dots, 64 output pads are formed.
At both ends, a data-in terminal pad and a data-out terminal pad are formed. A 64-bit shift register is built in the driving IC.
The shift register in each drive IC is made substantially continuous by conducting between the data-out terminal pad and the data-in terminal pad of the adjacent drive IC on the substrate. A shift register of 2048 bits is substantially formed. The continuity between the data-out terminal pad and the data-in terminal pad is achieved by directly wire bonding between the pads,
This is achieved by wire bonding via a wiring pattern formed on the head substrate.

The 64 output pads of each drive IC are connected by wire bonding to one end of an individual electrode wiring formed on the head substrate.
The drive IC is electrically connected to each heating dot to be driven.

When print data of 2048 bits per line of B4 size is serially input from the data-in terminal of the first drive IC, this data is sequentially transferred to the downstream side of the shift register in accordance with a clock signal. The data is held in the shift register having a total of 2048 bits. Then, in accordance with a strobe signal commonly input to each drive IC, print data for 64 bits in each drive IC is output. Specifically, each drive IC has 64
In accordance with the print data for the bits, the corresponding output pad or the heat generating dot conducting to the corresponding output pad is turned on.

[0007]

In the above-described drive IC for a print head, the number of heat-generating dots, that is, the number of bits of the internal shift register tends to increase. The reasons are: first, the advancement of IC manufacturing technology has made it possible to achieve higher integration; second, the demand for smaller printheads, especially thermal printheads, has been stronger. In addition, the number of parts can be reduced to reduce the manufacturing cost.

At present, 64 bits are mainly used for the print head driving IC, but 96 bits or 128 bits are being put into practical use, and a driving IC having a larger number of bits will be developed in the future. It is likely to be.

Now, consider the case where a thermal print head capable of printing in B4 size and A4 size at a printing density of 200 dpi using a 128-bit drive IC is considered. For that purpose, 2048 dots of heat-generating dots are required, and 16 drive ICs for driving each 128 dots are mounted on the head substrate. B4 size printing can be performed without any problem by inputting print data for 2048 dots per line as described above.

On the other hand, in the case of A4 size, one line of print data is formed of 1728 bits. Then, it is preferable to drive the central 1,728 dots of the 2,048 heat-generating dots to perform printing, from the viewpoint of configuring a printing apparatus. That is, A4 size printing should be performed using the heating dots from the 161st dot to the 1888th dot. For this purpose, when the B4 size thermal print head is used, the first of the 2048-bit print data per line is used.
Data processing for inserting blank data into the 160th bit and the 1889th to 2048th bits is required, which complicates the control circuit and cannot increase the processing speed.

Next, a case is considered in which a thermal print head dedicated to the A4 size is formed at a print density of 200 dpi. For example, in the United States and Europe, most documents are in the A4 size, so a facsimile machine for the United States and the United States suffices with an A4 size dedicated machine. Since the print data of one line of A4 size is 1728 bits, the drive IC of 32 bits is used.
In this case, 1728 ＝ 32 = 54 pieces, 1728 ÷ 64 = 27 pieces for a 64-bit drive IC, and 1728 ÷ 96 = 18 pieces of drive ICs for a 96-bit drive IC.
However, if a 128-bit drive IC is used, 1728 ÷ 128 = 13.5, and the 14th drive IC does not require 64 bits out of 128 bits. Inserting blank data into such unnecessary bits complicates processing, and using only the 14th drive IC of 64 bits requires 64 bits separately from the 128-bit drive IC. Means that it is necessary to manufacture the drive IC, and the configuration of the entire print head cannot be uniform.

The present invention has been conceived in view of the above circumstances, and a single type of highly integrated driving IC can be used without significantly increasing the complexity of print data processing. It is an object of the present invention to provide a printhead drive IC which can easily cope with the print size of the above and a printhead using the same.

[0013]

In order to solve the above-mentioned problems, the present invention employs the following technical means.

That is, according to the invention described in claim 1 of the present application, a predetermined number of output pads arranged along one side edge of the upper surface of a chip, a shift register having a bit number corresponding to the number of output pads, A print head drive IC having a data-in terminal connected to the first bit of a shift register and a data-out terminal connected to an end bit of the shift register, wherein the shift register is divided into a plurality of parts, , Additional data leading to the end bit of the data-in side split shift register
And out terminal, and the additional data in terminal connected to the first bit of the split shift register of the data-out side, Ji
It is characterized by being provided adjacent to each other along the other side edge of the top surface of the top .

According to a second aspect of the present invention, in the print head drive IC of the first aspect, the number of the output pads is 96 and the number of the shift registers is 96.
This shift register is characterized in that this shift register is divided into three parts each having 32 bits.

According to a third aspect of the present invention, in the print head drive IC of the first aspect, the number of the output pads is 128 and the number of the shift registers is one.
The shift register has 28 bits, and the shift register is characterized in that the shift register is divided into four 32 bits.

According to a fourth aspect of the present invention, there is provided a print head on which the drive IC for a print head according to the first, second or third aspect is mounted.

According to a fifth aspect of the present invention, there is provided a print head comprising a plurality of the print head drive ICs according to the first aspect mounted on a substrate, wherein the data out terminal of the adjacent drive IC is connected to the data output terminal. Conduction between the IN terminal and conduction between the additional data-out terminal and the additional data-in terminal in each drive IC, while data-out terminal of the first drive IC and data-out of the rear drive IC A first data transfer system between the terminals and a second data transfer system between the selected additional data-in terminal and the additional data-out terminal selected on the rear end side. I have.

According to a sixth aspect of the present invention, there is provided a print head comprising a plurality of the print head drive ICs according to the first aspect mounted on a substrate, wherein a data-out terminal of the adjacent drive IC and a data-out terminal are provided. -While conducting between the IN terminals, a selected one of the data-in terminal of the first drive IC or the additional data-in terminal of the first drive IC is used as a data input portion, and the additional data out of the rear-end drive IC is selected. The terminal or the data out terminal of the drive IC at the rear end is selected as a data output unit, and each drive IC
The adjacent additional data out terminal between the data input section and the data output section and the additional data
It is characterized by conducting between the in terminals.

According to a seventh aspect of the present invention, in the print head according to the fifth or sixth aspect, conduction between a data-out terminal and a data-in terminal in adjacent drive ICs and / or a connection between each drive IC is provided. The conduction between the additional data-out terminal and the additional data-in terminal is performed by wire bonding between the wiring pattern formed on the substrate and each of the terminals.

The print head of the present invention may be a thermal print head (claim 8) or an LED print head (claim 9).

[0022]

The drive IC for a print head according to the present invention has one drive IC as compared with the conventional drive IC.
Is divided into a plurality of shift registers. The terminal bit of the data-in side divided shift register is connected to an additional data-out terminal provided on the drive IC, and the leading bit of the data-out side divided shift register is provided on the drive IC. Connected to additional data in terminal. Therefore, if the additional data-out terminal and the additional data-in terminal are electrically connected, the drive IC becomes functionally the same as the conventional drive IC.

In each divided shift register, the first bit is always connected to the data-in terminal or the additional data-in terminal, and the last bit is always connected to the data-out terminal or the additional data-out terminal.
This drive IC can function as a drive IC having the number of bits of the divided shift register or the number of bits that is an integral multiple of the number of bits.

According to the driving IC of the second aspect,
Assuming that a 6-bit shift register is divided into three parts of 32 bits each, this driving IC is a 96-bit driving IC.
In addition to being able to function as a 32-bit and 64-bit driving IC, the present invention can be used.

According to the driving IC described in claim 3, 1
Assuming that a 28-bit shift register is divided into three parts of 32 bits each, this drive IC can function as a 128-bit drive IC.
It can function as a 4-bit or 96-bit drive IC.

The print head according to the fifth aspect is configured to have two data transfer systems using a plurality of drive ICs having the above functions.
In this way, for example, a data transfer system for B4 size print data and a data transfer system for A4 size print data can be set separately. When the shift register of a 128-bit drive IC is divided into four sections of 32 bits each, first, 16 drive ICs are mounted on a head substrate, and a data-out terminal and a data-in terminal of each drive IC are connected. While conducting, each drive I
In C, the 32-bit divided shift registers are connected by conducting between the additional data out terminal and the additional data in terminal.

As a result, all the shift registers are connected in series to form a 2048-bit shift register. A 2048-bit B4 size first data transfer system is formed between the data-in terminal of the first (first) drive IC and the data-out terminal of the rear (16th) drive IC. .

Then, between the additional data-in terminal of the second divided shift register of the second driving IC and the additional data-out terminal of the third divided shift register of the fifteenth driving IC, A second data transfer system for A4 size consisting of 1728 bits at the center is formed.

When performing B4 size printing, the first print data transfer system is selected in control. Also, when performing A4 size printing, in the control,
The second print data transfer system is selected. Therefore, the print data processing and control are simplified as compared with the conventional method in which blank data is inserted into the leading portion and the trailing end portion of the 2048-bit print data to substantially perform the print of 2048 bits. .

The print head according to the sixth aspect is such that a desired print width can be easily achieved by using a plurality of drive ICs having the above functions. For example, by using 16 128-bit drive ICs, a B4 size print head can be configured using all the bits of the shift register in each drive IC as described above. According to the present invention, by using the same 128-bit drive IC, an A4 size print head can be configured as follows without preparing various types of drive ICs.

That is, the number of bits of one line of print data of A4 size is 1728 bits.
From ÷ 128 = 13.5, 13 drive ICs using all of the 128-bit shift registers and one drive IC using the 64-bit divided shift registers may be connected and used.

The distance between the data-out terminal and the data-in terminal of each drive IC, the distance between the additional data-out terminal and the additional data-in terminal of each drive IC, and the wiring pattern formed on the substrate By conducting wire bonding on the substrate, conduction can be easily achieved. Drive IC
Since the output pad and the individual electrode are usually connected by wire bonding, the connection via the wire bonding between the data-out terminal and the data-in terminal does not involve much difficulty. .

As described above, according to the present invention, it is possible to easily configure an appropriate print head with a single type of drive IC in correspondence with a plurality of print sizes without complicating print data processing. it can.

Further, standardization of highly integrated drive ICs having a large number of bits has been advanced, and such standardized drive ICs have been developed.
With C, it is possible to meet various demands such as print width and data division control, and it is possible to expect cost reduction due to downsizing of the print head in addition to cost reduction of the drive IC.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.
This will be specifically described with reference to the drawings.

FIG. 1 schematically shows the configuration of an embodiment of a print head drive IC 1 according to the present invention. The drive IC1 is 128 bits drive IC, one side edge of the upper surface of the chip, 128 output pads 2 ₁ to 2 ₁₂₈ are provided in a staggered manner. Inside the driving IC 1, 1
28-bit shift register 3 has is formed, the bits 3 ₁ to 3 ₁₂₈ corresponds with the respective output pads 2 ₁ to 2 _128.

The shift register 3 is divided into four parts each having 32 bits, and these divided shift registers are divided into divided shift registers 3a to 3d.
That.

At one end (left end in FIG. 1) of the other side edge of the upper surface of the drive IC chip, a data-in terminal pad 4a connected to the _first bit 31 of the shift register 3 is provided at the other end (right end in FIG. 1). ), the data out pin pad 5d lead to termination bit 3 ₁₂₈ of the shift register 3,
Each is provided. In addition, a dividing portion between the first divided shift register 3a and the second divided shift register 3b includes:
And additional data out terminal pad 5a leading to the end bit 3 ₃₂ of the first split shift register 3a, and additional data-in terminal pads 4b connected to the first bit 3 ₃₃ of the second split shift register 3b is provided adjacent to each other ing. Similarly, the divided parts of the second split shift register 4b and the third split shift register 3c, and additional data out terminal pad 5b connected to the end bit 3 ₆₄ of the second split shift register 3b, third split shift register Additional data in terminal pad 4 leading to the first bit 3 _{65 of} 3c
c are provided adjacent to each other. Then, the divided portions of the third split shift register 3c and fourth divided shift register 3d, additional data out terminal pad 5c connected to the terminating bits 3 ₉₆ of the third split shift register 3c
When the additional data in terminal pads 4d connected to the first bit 3 ₉₇ of the fourth split shift register 3d are provided adjacent to each other.

A clock signal input pad 6, a strobe signal input pad 7, a logic power supply pad 9, a power ground pad 10, and the like are further provided on the upper surface of the chip 1 of the drive IC as required.

As shown in FIG. 1, each of the divided shift registers 3a to 3d has an additional data out terminal pad 5.
a, 5b, 5c and additional data-in terminal pads 4b, 4
By making c and 4d conductive, a series of 128-bit shift registers can be formed, and each of the additional data-in terminal pads 4b, 4c and 4d or each of the additional data-out terminal pads 5a, 5b and 5c can be connected. It can also be used as an independent data in terminal or data out terminal.

In FIG. 1, the continuity between the additional data out terminal pads 5a, 5b, 5c and the additional data in terminal pads 4b, 4c, 4d is determined by the wiring pattern 12 formed on the head substrate 11 and each pad. This is achieved by wire bonding between the pads, but it is also possible to perform wire bonding directly between the pads.

In FIG. 1, reference numeral 13 denotes an auxiliary data-in terminal pad. When all of the divided shift registers 3a to 3d are used as a series of shift registers, the use of the auxiliary data-in terminal pad 13 causes all of the divided shift registers to be internally connected to each other as described above. Data out terminal pad 5
a, 5b, 5c and each additional data-in terminal pad 4b,
It is configured such that the operation of conducting between the 4c and 4d is not required. In addition, such auxiliary data
Whether to provide the in-terminal pad 13 is optional.

FIG. 2 is a circuit diagram of the driving IC 1 shown in FIG.
The thermal print head 14 is configured to print at a print density of 00 dpi in both the B4 size and the A4 size.

Along the one side edge of the insulating substrate 11 having a rectangular shape, 2048 heating dots D _{1 to} D ₂₀₄₈ are arranged. Then, the heating dots D _{1 to} D ₂₀₄₈ are set to
16 drive ICs 11 ₁ to ₁ that are driven by each dot
₁₆ are arranged in a horizontal line. Each heating dot D _{1 to} D
Individual electrode wiring 15 with one end conducting to ₂₀₄₈
Extend to the vicinity of one side edge of each drive IC 1, and these individual electrode wirings 15 are connected to the corresponding output pads 21-2 ₁₂₈ on the drive IC ₁ by wire bonding.

[0045] As each additional data out terminal pad 5a at each drive IC1 ₁ ~1 _16, 5b, and 5c, each additional data in terminal pads 4b, 4c, the inter-4d, already described with reference to FIG. 1 To be conductive and the first
The fourth to fourth divided shift registers 3a to 3d are connected in series. Further, between adjacent drive ICs, wire bonding is also performed between the data-out terminal pad 5d of the preceding drive IC and the data-in terminal pad 4a of the subsequent drive IC via the wiring pattern 12 on the substrate. Is made conductive. As a result, all shift registers in each drive IC are connected in series, and 2048
The bit shift register is completed.

[0046] The first drive IC1 ₁ data-in terminal pads 4a is being linked by wire bonding to the data-in line extending from the main data-in terminal 16 on the substrate, the data of the 16-th drive IC1 ₁₆ Out terminal pad 5d is the main data out terminal 1 on the board
7 is connected to the data out wiring extending from the wiring 7 by wire bonding. Thus, the main data-in terminal 1
A main data transfer system for printing B4 size data consisting of 2048 bits and extending from 6 to the main data out terminal 17 is formed.

Second drive IC 1_TwoSecond division in
First bit 3 of shift register 3b ₃₃Additional data leading to
Data-in terminal pad 4b is also
Connected to the data-in wiring extending from the
ing. Then, the fifteenth drive IC1_FifteenIn the
Terminal bit 3 of three-division shift register 3c₉₆Leads to
The additional data out terminal pad 5c is also
A sub data out distribution extending from the data out terminal 19
It is connected to a line. Thus, the sub data in terminal
1728 bits from 18 to the sub data out terminal 19
A sub-data transfer system for A4 size printing
You.

When printing in B4 size, the main data transfer system is selected in control, and when printing in A4 size, the sub data transfer system is selected in control.

As described above, in the present invention, the driving I
Since an additional data out terminal and an additional data in terminal are provided in C, as shown in FIG. 2, when printing in B4 size and printing in A4 size can be performed,
The print data processing can be performed efficiently while the A4 print width can be arranged at the center.

FIG. 3 shows a case where the driving IC shown in FIG.
An example is shown in which a thermal print head dedicated to size is configured. Since the print width of the A4 size is 1728 dots, one of the 14 drive ICs is 64
Only the bits need to function. Again in this case,
As shown in FIG. 3, the data out terminal pad 5b connected to the terminal bit of the second divided shift register of the fourteenth drive IC may be connected to the data out wiring on the substrate.

FIG. 4 shows a second embodiment of the print head drive IC according to the present invention.
The bit shift register 3 is divided into three parts each having 32 bits. Similarly to the drive IC shown in FIG. 1, each of the divided shift registers can be connected via an additional data-out terminal pad and an additional data-in terminal pad.・
The in-terminal pad can be used as an independent terminal.

Of course, the scope of the present invention is not limited to the above embodiment. For the drive IC, the basic bit number may be other than 64, 96, and 128.
Further, the shift register can be divided for every arbitrary number of bits.

Although the embodiment has been described on the assumption that the thermal print head is configured, the basic configuration and control mode of the drive IC are the same for the LED print head. Therefore, the present invention can be applied to a thermal print head, an LED print head, and other print heads that can perform printing under similar control using similar print data.

Further, the mode of forming a print head using the driving IC of the present invention is not limited to the above-described embodiment. For example, when performing color printing,
Since faster print data processing is required, it is necessary to divide print data into a plurality of print widths and process them simultaneously. Even in such a case, according to the present invention, it is easy to divide the print width into a plurality of bits having an arbitrary number of bits and to set the data-in terminal and the data-out terminal for each of the divided print widths. , So that the above request can be easily answered.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing the configuration of an embodiment of a printhead drive IC according to the present invention.

FIG. 2 is a schematic plan view showing an example of a thermal print head configured using the driving IC of FIG.

FIG. 3 is a schematic plan view showing another example of a thermal print head configured using the drive IC of FIG.

FIG. 4 is a plan view schematically showing the configuration of another embodiment of the printhead drive IC of the present invention.

[Explanation of symbols]

First driving IC 2 ₁ to 2 ₁₂₈ output pads 3 shift register 3a~3d split shift register 4a Data In terminal pads 4b, 4c, 4d additional data in terminal pads 5a, 5b, & 5c additional data out terminal pad 5d data Out terminal pad 11 Head substrate 14 Thermal print head 15 Individual electrode wiring D _{1 to} D ₂₀₄₈ print dots (heat generation dots)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI H04N 1/032 (58) Investigated field (Int.Cl. ⁷ , DB name) B41J 2/345 B41J 2/44 B41J 2/45 B41J 2/455

Claims (9)

(57) [Claims] 1. A predetermined number of output pads arranged along one side edge of an upper surface of a chip, a shift register having a bit number corresponding to the number of output pads, and a leading bit of the shift register. What is claimed is: 1. A print head drive IC having a data-in terminal and a data-out terminal connected to a terminal bit of the shift register, wherein the shift register is divided into a plurality of parts, and each division part is divided into a data-in part. The additional data out terminal connected to the end bit of the shift register and the additional data in terminal connected to the first bit of the divided shift register on the data out side are connected to each other along the other side edge of the top surface of the chip.
A print head drive IC, which is provided adjacent to a print head. 2. The printhead drive IC according to claim 1, wherein the number of said output pads is 96, said shift register is 96 bits, and said shift register is divided into three by 32 bits. Head drive IC. 3. The printhead drive IC according to claim 1, wherein the number of the output pads is 128, the shift register is 128 bits, and the shift register is divided into four by 32 bits. Head drive IC. 4. A printhead on which the printhead drive IC according to claim 1, 2 or 3 is mounted. 5. A print head comprising a plurality of print head drive ICs according to claim 1 mounted on a substrate,
While conducting between the data-out terminal and the data-in terminal of the adjacent driving IC and conducting between the additional data-out terminal and the additional data-in terminal in each driving IC, the data-in terminal of the leading driving IC is connected. A first data transfer system is provided between the terminal and the data out terminal of the drive IC at the rear end, and a first data transfer system is provided between the selected additional data in terminal and the additional data out terminal selected at the rear end side. 2. A print head, characterized in that the print head has a second data transfer system. 6. A print head comprising a plurality of print head drive ICs according to claim 1 mounted on a substrate,
While conducting between the data-out terminal and the data-in terminal of the adjacent drive IC, the data
The selected one of the IN terminal or the additional data-in terminal of the leading drive IC is used as the data input part, and the drive I
A selected one of the additional data out terminal of C and the data out terminal of the driving IC at the rear end is used as a data output unit, and the adjacent one between the data input unit and the data output unit in each driving IC. A print head, wherein conduction is established between matching additional data-out terminals and additional data-in terminals. 7. The continuity between a data out terminal and a data in terminal in an adjacent driver IC and / or the continuity between an additional data out terminal and an additional data in terminal in each driver IC are formed on a substrate. The print head according to claim 5, wherein the connection is performed by wire bonding between a wiring pattern and each of the terminals. 8. The printhead according to claim 5, wherein the printhead is a thermal printhead. 9. The printhead according to claim 5, wherein the printhead is an LED printhead.