Inkjet recording apparatus

Abstract

The inkjet recording apparatus includes: a casing; an inkjet head which is arranged in the casing and ejects ink from nozzles toward a recording medium; a scanning device which is arranged in the casing and moves the inkjet head to scan the recording medium in a scanning direction parallel with a breadthways direction of the recording medium; a recording medium supply device which accommodates the recording medium and is removably installed into the casing via a front face side of the casing and disposed on a lower side of the inkjet head in a vertical direction of the casing; a conveyance device which conveys the recording medium from the recording medium supply device to a recording region where the recording medium receives deposition of the ink ejected from the inkjet head, and conveys the recording medium within the recording region in a direction substantially perpendicular to the scanning direction; an ink cartridge which accommodates the ink to be supplied to the inkjet head and is removably installed into the casing via the front face side of the casing and disposed between the inkjet head and the recording medium supply device in the vertical direction of the casing; and an ink supply channel which is provided between the ink cartridge and the inkjet head.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The nature of this invention, as well as other objects and advantages thereof, will be explained in the following with reference to the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures and wherein:

FIG. 1 is a basic schematic drawing of an inkjet recording apparatus according to an embodiment of the present invention;

FIG. 2 is a plan diagram showing a nozzle arrangement in the inkjet head shown in FIG. 1;

FIG. 3 is a diagram showing the inner structure of the inkjet head shown in FIG. 1;

FIG. 4 is a block diagram showing the approximate composition of a control system of the inkjet recording apparatus shown in FIG. 1;

FIG. 5 is an oblique diagram showing the appearance of a sub cartridge installed in the inkjet recording apparatus shown in FIG. 1;

FIG. 6 is an approximate plan diagram of the sub cartridge shown in FIG. 5;

FIG. 7 is a diagram showing the composition of a negative pressure maintaining unit connected to the print head shown in FIG. 1;

FIGS. 8A and 8B are diagrams for illustrating the structure of a valve connected to the bubble expulsion aperture shown in FIG. 7;

FIGS. 9A and 9B are diagrams for illustrating the structure of a sub cartridge coupling unit and an ink supply coupling unit;

FIG. 10 is a diagram for illustrating the structure of the sub tank shown in FIG. 7;

FIGS. 11A and 11B are diagrams illustrating pressure determination in a negative pressure maintaining unit;

FIG. 12 is an oblique diagram showing the appearance of an ink accommodating bag;

FIGS. 13A, 13B and 13C are diagrams for illustrating the determination of the residual amount in the ink cartridge;

FIG. 14 is a flowchart showing a control sequence of determination of the residual amount in the ink cartridge;

FIG. 15 is a diagram illustrating ink supply in the inkjet recording apparatus shown in FIG. 1; and

FIG. 16 is a flowchart showing the sequence of ink supply control during printing in the inkjet recording apparatus shown in FIG. 1.

Claims

1. An inkjet recording apparatus, comprising: a casing;an inkjet head which is arranged in the casing and ejects ink from nozzles toward a recording medium;a scanning device which is arranged in the casing and moves the inkjet head to scan the recording medium in a scanning direction parallel with a breadthways direction of the recording medium;a recording medium supply device which accommodates the recording medium and is removably installed into the casing via a front face side of the casing and disposed on a lower side of the inkjet head in a vertical direction of the casing;a conveyance device which conveys the recording medium from the recording medium supply device to a recording region where the recording medium receives deposition of the ink ejected from the inkjet head, and conveys the recording medium within the recording region in a direction substantially perpendicular to the scanning direction;an ink cartridge which accommodates the ink to be supplied to the inkjet head and is removably installed into the casing via the front face side of the casing and disposed between the inkjet head and the recording medium supply device in the vertical direction of the casing; andan ink supply channel which is provided between the ink cartridge and the inkjet head.

2. The inkjet recording apparatus as defined in claim 1, further comprising: a coupling unit which is provided in at least one end portion of a scanning region of the inkjet head, and couples and separates the inkjet head with and from the ink supply channel,wherein the inkjet head and the ink supply channel are coupled together through the coupling unit when the ink is supplied to the inkjet head, and the inkjet head and the ink supply channel are separated from each other when the inkjet head is carrying out printing.

3. The inkjet recording apparatus as defined in claim 2, further comprising: a sub cartridge which includes the coupling unit, the ink supply channel, and an ink cartridge accommodating section which accommodates the ink cartridge, wherein:the sub cartridge is removably installed into the casing via the front face side of the casing and disposed to a lower side of the scanning region of the inkjet head in the vertical direction of the casing; andthe ink cartridge accommodating section has an introduction aperture for introducing the ink cartridge in a face of the sub cartridge which faces the front face of the casing when the sub cartridge is installed in the casing.

4. The inkjet recording apparatus as defined in claim 3, further comprising: a restoration processing device which carries out restoration process of the inkjet head,wherein the sub cartridge includes a waste ink accommodating section which accommodates waste ink generated during the restoration process of the inkjet head performed by the restoration processing device and is removably installed into the sub cartridge.

5. The inkjet recording apparatus as defined in claim 3, wherein the sub cartridge includes an ink receiving section which receives the ink ejected beyond edges of the recording medium during full-surface printing for a region corresponding to the scanning region of the inkjet head and is removably installed into the sub cartridge.

6. The inkjet recording apparatus as defined in claim 5, wherein the ink receiving section serves as a conveyance guide for the recording paper in the print region.

7. The inkjet recording apparatus as defined in claim 2, further comprising a negative pressure maintaining unit which includes: an ink supply port which has a first opening and closing member, couples with the coupling unit, and is connected to an ink flow channel inside the inkjet head; anda sub tank of which portion of wall has an elastically deformable member, and is provided between the inkjet head and the ink supply port,wherein the negative pressure maintaining unit couples with the ink supply channel and maintains an internal pressure of the inkjet head at a liquid head pressure differential between the inkjet head and the ink cartridge during supply of the ink to the inkjet head, and seals an interior of the inkjet head by closing the first opening and closing member when the inkjet head is carrying out printing.

8. The inkjet recording apparatus as defined in claim 7, further comprising: a volume determination device which determines a volume change in the sub tank according to an amount of deformation of the elastically deformable member,wherein the internal pressure of the inkjet head is determined through the volume determination device, and the inkjet head and the ink supply channel is coupled and separated in accordance with the determined internal pressure of the inkjet head.

9. The inkjet recording apparatus as defined in claim 7, wherein: the negative pressure maintaining unit further includes:a bubble collecting section which is disposed on an upper side of the sub tank, bubbles separated from the ink in the sub tank collecting in the bubble collecting section; anda bubble expulsion port through which the bubbles collected in the bubble collecting section are expelled, andthe inkjet recording apparatus further comprises:a bubble expulsion channel which has a second opening and closing member and connects with the bubble expulsion port in the upper part of the negative pressure maintaining unit; anda suctioning device which suctions an interior of the negative pressure maintaining unit from an end of the bubble expulsion channel opposite to an end connecting to with the bubble expulsion port.

10. The inkjet recording apparatus as defined in claim 9, wherein the suctioning device serves as a suctioning device for suctioning the interior of the inkjet head from an ink ejection face of the inkjet head.

11. The inkjet recording apparatus as defined in claim 10, further comprising a suction switching device which switches the suctioning device between suctioning from the bubble expulsion port of the negative pressure maintaining unit and suctioning from the ink ejection surface of the inkjet head.

12. The inkjet recording apparatus as defined in claim 1, wherein the ink cartridge includes: an ink cartridge container of which interior is connectable to atmosphere; andan ink accommodating member which holds the ink, is accommodated in the interior of the ink cartridge container, has a planar shape of a similar form to the ink cartridge container, and has folds which allow the ink accommodating member to fold in a concertina fashion in the vertical direction as an amount of the ink inside the ink accommodating member decreases.