An Ink Cartridge

The present invention relates an ink cartridge for a printer comprising a print head and a contact for receiving print head control signals.

Inkjet printers can be classified into either shuttle type or array type inkjet printers. Shuttle type ink jet printers print using only one head chip. Array type inkjet printers print at high speed by using a plurality of head chips.

Both shuttle and array type inkjet printers eject ink onto a print medium by using printing data transmitted from a host such as a computer to the head chip(s) which use this data to form an image. A known arrangement for transmitting printing data is shown in Figure 1.

Referring to Figure 1, a first cable 10, a drive substrate 20, a second cable 30 and a head cable 40 are typically used to transmit the printing data as described above to a head chip 35 on an ink cartridge 60.

The first cable 10 is electrically connected to a main board (not shown) of the inkjet printer. The main board receives printing data from a host such as a computer. The main board transmits the printing data to the substrate 20. The printing data received by the drive substrate 20 is transmitted to the second cable 30 and the printing data received by the second cable 30 is fed to the head chip 35 of the ink cartridge 60 via the head cable 40. Then, the head chip 35 ejects ink onto a printing medium (such as paper) according to the transmitted printing data, thereby forming an image.

With the above-mentioned arrangement for transmitting the printing data, the head cable 40 is attached to the rear and bottom sides of the ink cartridge 60. The second cable 30 is in direct contact with the head cable 40 to establish an electrical connection. In addition, in order to enhance the contact between the second cable 30 and the head cable 40, an elastic member 50 for compressing the second cable 30 is interposed between a carrier 70 of the ink cartridge 60 and the second cable 30.

However, because the above-mentioned arrangement is complicated in construction, the path which the printing data has to follow is also complicated. Accordingly, the likelihood of losing printing data is increased.

Also, the elastic member 50 is fixed to the side of the printer. Thus, the printer may become useless if the elastic member 50 is hardened due to repeated or long-term use. Accordingly, the life span of the printer may be shortened.

Accordingly, there is a need for an improved printing apparatus having a simplified arrangement to transmit the printing data to a head chip. The simplified arrangement improves contact between the head cable and the drive substrate to prevent loss of the printing data.

Accordingly, aspects of the present invention are to solve at least the above problems and/or disadvantages and to provide at least the advantages described below. Therefore, an object of the present invention is to provide an ink cartridge unit that reduces the number of components and simplifies the construction of the ink cartridge unit and an inkjet printer having the same.

Another object of the present invention is to provide an inkjet printer with increased reliability.

Still another object of the present invention is to provide an inkjet printer with a prolonged life span.

The present invention relates to an ink cartridge for a printer comprising a print head and a contact for receiving print head control signals.

An ink cartridge according to the present invention is characterised in that the contact comprises a projecting contact element.

An ink cartridge according to the present invention is also characterised by means for resiliently biasing the contact in a given direction.

The present invention also relates to a printer comprising an ink cartridge carriage.

A printer according to the present invention is characterised in that the ink cartridge carriage has a contact pad fixedly mounted therein.

Additional preferred and optional features are set forth in claims 22 and 25 appended hereto.

An embodiment of the present invention will now be described, by way of example only, and with reference to Figures 2 to 7, in which: <ul id="ul0001" list-style="none" compact="compact"><li>Figure 1 is a cross-sectional view showing a contact arrangement between a drive substrate and a head cable of a known inkjet printer;</li><li>Figure 2 is a perspective view schematically showing a shuttle type inkjet printer, in accordance with the present invention;</li><li>Figure 3 is a cross-sectional view taken along line III-III of Figure 2;</li><li>Figure 4A is a cross-sectional view schematically showing a main part of an inkjet printer according to the present invention;</li><li>Figure 4B shows part C of Figure 4A in detail;</li><li>Figure 5 is an exploded perspective view schematically showing a main part of an array type inkjet printer in accordance with the present invention;</li><li>Figure 6 is a cross-sectional view taken along line VI-VI of Figure 5; and</li><li>Figure 7 is a cross-sectional view schematically showing an arrangement in which a main board and a head cable of an array type inkjet printer are directly contacted with each other.</li></ul>

Throughout the drawings, the same drawing reference numerals will be understood to refer to the same elements, features, and structures.

The matters defined in the description such as a detailed construction and elements are provided to assist in a comprehensive understanding of the embodiments of the invention. Also, descriptions of known functions and constructions are omitted for conciseness.

Referring to FIGS. 2 and 3, the inkjet printer according to the present invention comprises a printer body 100, a transfer shaft 101, a first cable 110, a drive substrate 120 and an ink cartridge unit 130.

The printer body 100 is provided with various image forming parts.

Opposite ends of the transfer shaft 101 are secured to the printer body 100 to guide the cartridge unit 130 in the left and right direction.

The first cable 110 is constituted of a flexible printed circuit (FPC) and is connected to a main board (not shown) installed within the printer body 100. The other end of the first cable 110 is connected to the drive substrate 120. In the present embodiment, although the first cable 110 is illustrated as being connected to the main board, the drive substrate 120 may also serve as the main board in an array type inkjet printer. In that case, the first cable 110 would be directly connected to a host such as a computer.

The drive substrate 120 is formed with a circuit pattern. A plurality of contact pads 122 within the circuit of the drive substrate 120 are externally exposed on one side of the drive substrate 120 allowing the ink cartridge unit 130 to be connected to the drive substrate 120. The drive substrate 120 extracts the printing data transmitted through the first cable 110 and amplifies the received printing data signals.

The ink cartridge unit 130 comprises a head cable 132, an ink cartridge 134, an ink cartridge carrier 136 and an elastic member 138.

The head cable 132 is fixed to the bottom side of the ink cartridge 134 allowing one end to be connected to the drive substrate 120. The other end is connected to the head chip 135 of the ink cartridge 134. Head cable 132 may also be an FPC. In addition, a plurality of first projections 133 which align with the contact pads 122 are formed on the side of the head cable 132 facing the drive substrate 120. The first projections 133 directly contact the contact pads 122. Thus, the drive substrate 120 and the head cable 132 are connected to each other.

The ink cartridge 134 stores ink. A head chip 135 is provided on the bottom side of the ink cartridge 134 to eject ink in accordance with printing data transmitted through the head cable 132 onto a printing medium to form an image.

The ink cartridge carrier 136 houses the ink cartridge 134. The ink cartridge 134 can be removed from the ink cartridge carrier 136. In a shuttle type inkjet printer, the ink cartridge carrier 136 moves the ink cartridge 134 left and right along the transfer shaft 101 when printing.

The elastic member 138 is fixed to the rear side of the ink cartridge 134 allowing the head cable 132 to press against the drive substrate 120. The elastic member 138 is formed from elastic rubber. In addition, a plurality of second projections 139 are formed on the side of the elastic member 132 facing the head cable 132. The plurality of second projections 139 align with the first projections 133, so that the contact pads 122, the first projections 133 and the second projections 149 are all aligned. The second projections 139 concentrate the pressure on the first projections 133 of the head cable 132. Thus, the first projections 133 and the contact pads 122 more effectively contact each other. Further, the first and second projections 133, 139 are preferably dome-shaped, so that the first projections 133 are more stable in their contact with the contact pads 122.

Operation of the inkjet printer constructed as above will now be described in more detail.

When a computer issues a request to print, printing data is transmitted to the drive substrate 120 through the first cable 110. The drive substrate 120 extracts and amplifies the transmitted data. The data is transmitted to the head cable 132 via the first projections 133 which contact with the contact pads 122. The printing data is then transmitted to the head chip 135 which ejects ink stored in the ink cartridge 134 onto paper in accordance with the printing data.

The above-mentioned inkjet printer is not provided with the existing second cable 30, as seen in Figure 1. Therefore, the number of parts is reduced. In addition, because the path which the printing data travels is shorter, the data is more reliably transmitted. Also, because the elastic member 138 is attached to an exchangeable ink cartridge 134, it is easy to repair the printer by exchanging the ink cartridge unit 130 when the elastic member 138 becomes hardened. Thus, the life span of the printer is prolonged.

Referring to Figures 4A and 4B, elastic domes 233 (made of metal) are formed on the head cable 232, instead of the elastic member 138. The elastic domes 233 have an elasticity such that they to their original dome shape after an external force is removed, even if they are deformed by an external force. Preferably, the elastic domes 233 are similar to the metal terminals of a charger for a mobile telephone. However, the elastic domes 233 are not limited to steel domes and any member capable of forming contacts and having elasticity may be used.

Elastic domes 233 are pressed into contact with the drive substrate 220 when the ink cartridge 230 is mounted. Accordingly, the head cable 232 may elastically contact the drive substrate 220. The elastic domes 233 are pressed into contact with the contact pads 222 which are formed in the circuit pattern 221 on the drive substrate 220. This allows the printing data to communicate with the head chip 235. The construction of such a circuit pattern 221 is known and thus description thereof is omitted.

The inkjet printer constructed as mentioned above is operated in the following manner.

Printing data received by the drive substrate 220 is transmitted to the head chip 235 via the elastic domes 233 and the head cable 232. The construction and functional action of this embodiment are the same as those of the embodiment of Figure 2 and so detailed description thereof is omitted.

As the inkjet printer constructed as mentioned above is not provided with a second cable 30 and an elastic member 50, 138 as is known, not only are the material costs reduced, but the stability and reliability of the resultant product is enhanced due to the shortened path for transmitting printing data.

Referring to Figures 5 and 6, the array type inkjet printer is provided with a plurality of head chips 335 for the colours yellow, magenta, cyan and black on the bottom of an ink cartridge 334. In addition, a head cable 332 is fixed to the bottom side of the ink cartridge 334. Thus, the head cable 332 is connected to the head chips 335. The other end of the head cable 332 is provided with a plurality of first projections 333. The first projections 333 contact with contact pads 322 provided on the side of a contact board 320, such as a drive substrate 320. Also, an elastic member 338 is interposed between the head cable 332 and the ink cartridge 334 One side of the elastic member 338 is provided with a plurality of second projections 339 which are aligned with the first projections 333, thereby making the first projections 333 press into contact with the contact pads 322. The contact board 320 is connected to a main board 302 by the first cable 310, and so the main board 302 receives printing data transmitted from a host.

Referring to Figure 7, a plurality of contact pads 422 are formed on the main board 420. The first projections 433 which are formed on the head cable 432 contact the contact pads 422.

As described above, the inventive contact arrangement of a head cable and a drive substrate may apply to an array type inkjet printer by changing the size of the head cable and the drive substrate and the number of the contact points. Although Figures 5 to 7 only show one example to which the embodiment of the present invention of Figure 3 is applied, the other embodiment of Figures 4A and 4B may be identically applied to such an array type inkjet printer.

As described above, it is possible to save material costs because the number of parts are reduced by omitting a second cable and an elastic member which are needed in the prior art.

In addition, because the path travelled by the printing data is reduced, it is possible to reduce the risk of losing printing data. Thus, the resultant product is enhanced in stability and reliability.

Moreover, when the elastic member for compressing the head cable is hardened, it is possible to repair the printer in a simple manner by replacing the ink cartridge unit, which prolongs the life span of the printer.