Ink cartridge and recording apparatus

1. An ink cartridge, comprising:

a flexible ink bag configured to store ink and change in thickness thereof according to an amount of the ink;

a housing having a front surface, a first side surface and a second side surface opposite the first side surface, the housing being configured to accommodate the ink bag and to be mounted vertically with the first side surface projecting downward;

an inflow port formed in the front surface of the housing and in fluid communication with the inside of the ink bag to allow ink to flow into the ink bag, the inflow port being disposed between the first and second side surfaces of the housing at a position closer to the first side surface than to the second side surface;

an outflow port formed in the front surface of the housing and in fluid communication with the inside of the ink bag to allow the ink to flow out of the inside of the ink bag, the outflow port being disposed between the first and second side surfaces of the housing at a position above the inflow port when the housing is mounted vertically;

a first detection window formed on the first side surface of the housing;

a second detection window formed on the second side surface of the housing;

a plate that is fixed to an upper surface of the ink bag and that moves together with the ink bag within the housing in response to fluctuations in the amount of ink in the ink bag;

a first detecting member that detects an empty state of the ink bag and that is mounted to undergo movement following movement of the plate within the housing and to undergo movement to a position of closing the first detection window when the ink runs out and the ink bag is in the empty state, the first detecting member having a pin formed integrally with the plate and protruding toward the first side surface of the housing, a lever portion formed so as to extend unidirectionally from a proximal end side thereof to a tip end side thereof with the proximal end side being rotatably attached to the first side surface of the housing so that the lever portion slides on the first side surface, and a guide groove formed from the tip end side of the lever portion to the proximal end side thereof in a size allowing insertion of a tip end of the pin and by which the pin is guided following the movement of the plate, the lever portion moving to a position of closing the first detection window when the ink runs out; and

a second detecting member that detects a full state of the ink bag, the second detecting member being mounted to undergo movement following movement of the plate within the housing and to undergo movement to a position of closing the second detection window when at least a preselected amount of the ink is stored in the ink bag, the second detecting member having a protruding portion formed integrally with a side surface of the plate and protruding outwardly from the plate in a direction away from the ink bag, the protruding portion moving to a position of closing the second detection window when at least the preselected amount of the ink is stored in the ink bag.

2. An ink cartridge according to claim 1 ; wherein:

the plate is fixed to a center portion of the upper surface of the ink bag so as to extend in a longitudinal direction of the housing;

the first detection window is formed at a substantial center of the first side surface of the housing in the longitudinal direction thereof; and

the second detection window is formed at a substantial center of the second side surface of the housing in the longitudinal direction thereof.

3. An ink cartridge according to claim 1 ; wherein the housing is provided with a guide member for guiding a rotational movement of the lever portion.

4. A recording apparatus, comprising:

the ink cartridge according to claim 1 ;

a detection unit that detects opened/closed states of the first detection window and the second detection window, and detects a residual amount of the ink stored in the ink bag based on a result of the detection;

a recording head that ejects ink droplets on a recorded medium and performs recording thereon;

an ink supply tube that is connected to the outflow port and supplies the ink from the ink cartridge to the recording head;

a carriage portion that houses the recording head and slidingly moves the recording head on the recorded medium; and

a recorded medium conveyor portion that conveys the recorded medium.

5. A recording apparatus according to claim 4 ; wherein the detection unit includes:

a first detection unit that applies detection light toward the first detection window and detects the opened/closed state of the first detection window based on whether or not reflection of the detection light occurs; and

a second detection unit that applies detection light toward the second detection window and detects the opened/closed state of the second detection window based on whether or not reflection of the detection light occurs.

6. An ink cartridge comprising:

a flexible ink bag for storing ink and which undergoes expansion and contraction movement in accordance with fluctuations in the amount of ink stored in the ink bag, the ink bag having an ink inlet port for supplying ink into the ink bag and an ink outlet port for discharging ink stored in the ink bag;

a housing for accommodating the ink bag, the housing having a first side surface, a second side surface opposite the first side surface, and a front surface extending between the first and second side surfaces;

an inflow port formed in the front surface of the housing for connection to the ink inlet port of the ink bag;

an outflow port formed in the front surface of the housing for connection to the ink outlet port of the ink bag;

a first detection window formed on the first side surface of the housing and via which an empty state of the ink bag is detected;

a second detection window formed on a second side surface of the housing opposite the first side surface thereof and via which a full state of the ink bag is detected;

a plate member mounted to an upper surface of the ink bag for movement therewith in response to fluctuations in the amount of ink stored in the ink bag, the plate member having a protruding portion that closes the second detection window during movement thereof to detect the full state of the ink bag; and

a lever having a structure separate and independent from the plate member and being mounted to undergo movement with the plate member to close the first detection window to detect an empty state of the ink bag.

7. A recording apparatus, comprising:

the ink cartridge according to claim 6 ;

a detection unit that detects opened/closed states of the first detection window and the second detection window, and detects a residual amount of the ink stored in the ink bag based on a result of the detection;

a recording head that ejects ink droplets on a recorded medium and performs recording thereon;

an ink supply tube that is connected to the outflow port and supplies the ink from the ink cartridge to the recording head;

a carriage portion that houses the recording head and slidingly moves the recording head on the recorded medium; and

a recorded medium conveyor portion that conveys the recorded medium.

8. A recording apparatus according to claim 7 ; wherein the detection unit includes:

a first detection unit that applies detection light toward the first detection window and detects the opened/closed state of the first detection window based on whether or not reflection of the detection light occurs; and

a second detection unit that applies detection light toward the second detection window and detects the opened/closed state of the second detection window based on whether or not reflection of the detection light occurs.