Liquid cartridge

A liquid cartridge comprising:

• a casing having an upper edge and a bottom edge separated in a first direction;
• a liquid retaining chamber between the upper edge and the bottom edge;
• a liquid outlet in communication with the liquid retaining chamber extending from the casing in a second direction perpendicular to the first direction;
• a circuit board provided at the upper edge;
• a protrusion extending from the upper edge and defining an internal space in communication with the liquid retaining chamber, the protrusion being provided farther from the liquid outlet than the circuit board is from the liquid outlet in the first direction;
• and
• a locking surface provided at the upper edge, the locking surface being provided farther from the liquid outlet than the circuit board is from the liquid outlet in the first direction;
• wherein the protrusion is provided farther from the liquid outlet than the circuit board is from the liquid outlet in the second direction and provided closer to the liquid outlet than the locking surface is to the liquid outlet in the second direction.

A liquid cartridge comprising:

• a casing having an upper edge and a bottom edge separated from the upper edge in a downward direction;
• a liquid outlet extending from the casing in a forward direction perpendicular to the downward direction;
• a circuit board provided at the upper edge;
• a light attenuator which attenuates light traveling in a right direction or a left direction which is opposite to the right direction, wherein each of the right direction and the left direction is perpendicular to the downward direction and the forward direction, wherein the light attenuator is positioned at the upper edge, wherein a distance in an upward direction, which is opposite to the downward direction, from the liquid outlet to the light attenuator is greater than a distance in the upward direction from the liquid outlet to the circuit board;
• and
• a locking surface provided at the upper edge, wherein a distance in the upward direction from the liquid outlet to the locking surface is greater than a distance in the upward direction from the liquid outlet to the light attenuator,
• wherein a distance in a backward direction, which is opposite to the forward direction, from the liquid outlet to the light attenuator is greater than a distance in the backward direction from the liquid outlet to the circuit board and is less than a distance in the backward direction from the liquid outlet to the locking surface.