Abstract: An image forming apparatus which makes an appropriately timed query as to whether or not an ink cartridge has been replaced and performs maintenance which preferably reflects the input from a user to the query. When the upper body of the apparatus which is opened and closed for the replacement of an ink cartridge is opened and then closed, the user is asked which colors of ink cartridges have been replaced, and then whether the cartridge has been replaced by a new ink cartridge. Flushing is performed to un-replaced ink cartridges. A single purge is performed to the ink cartridges which have been replaced by previously used ink cartridges. And a replacement purge is performed to the ink cartridges which have been replaced by new ink cartridges.

Abstract: To accurately position and fix an ink cartridge on an ink cartridge mounting unit, a first engaging depression is formed in the bottom wall of the ink cartridge and a corresponding protrusion is formed in the mounting unit. Also, an ink supply port is formed in the bottom wall. When the ink cartridge is mounted on the mounting unit, the ink supply port is engaged first with an ink supply channel formed in the mounting unit and fluidly connected to the head unit. Then, the first engaging depression is brought into engagement with the corresponding protrusion in the mounting unit. A second engaging depression is further formed in the top. The engaging pawl of a locking arm engages the second engaging depression when the locking arm locks the ink cartridge to the head unit. Further, a pair of ribs is provided on the rear side wall of the ink cartridge. The ribs oppose each other with a prescribed interval.

Abstract: The invention relates to an ink cartridge wherein a remaining amount of ink can be detected using an optical sensor. The ink cartridge has a window, for detection of an ink remaining amount, that is inclined at a predetermined angle with respect to the vertical direction. Inside of the ink cartridge, a preventive member is vertically provided. When the ink level is up to the window, light irradiated from the optical sensor permeates the window. Then, the light passes through the ink and reaches the preventive member. Preferably, the window is inclined approximately 20 degrees with respect to the preventive member. Accordingly, an incident angle of the light that has reached the preventive member is different from an incident angle of the light to the window. Thus, most of the light that has reached the preventive member is absorbed or is reflected by the preventive member in a direction different from the incident direction, so that the light reflected toward the optical sensor can be restricted.

Abstract: An ink cartridge includes at least one wall; an ink chamber capable of storing ink, the ink chamber being bounded, at least in part, by the at least one wall; an ink supply opening configured to permit communication between the ink chamber and an area outside of the ink chamber; and a detection portion. The detection portion extends away from the ink chamber relative to portions of the ink cartridge adjacent to the detection portion, at least when the ink cartridge is installed in an image forming apparatus; and at least one part of the detection portion is capable of obstructing at least a portion of a light beam directed through the detection portion.

Abstract: To accurately position and fix an ink cartridge on an ink cartridge mounting unit, a first engaging depression is formed in the bottom wall of the ink cartridge and a corresponding protrusion is formed in the mounting unit. Also, an ink supply port is formed in the bottom wall. When the ink cartridge is mounted on the mounting unit, the ink supply port is engaged first with an ink supply channel formed in the mounting unit and fluidly connected to the head unit. Then, the first engaging depression is brought into engagement with the corresponding protrusion in the mounting unit. A second engaging depression is further formed in the top. The engaging pawl of a locking arm engages the second engaging, depression when the locking arm locks the ink cartridge to the head unit. Further, a pair of ribs is provided on the rear side wall of the ink cartridge. The ribs oppose each other with a prescribed interval.

Abstract: The invention relates to an ink cartridge wherein a remaining amount of ink can be detected using an optical sensor. The ink cartridge has a window, for detection of an ink remaining amount, that is inclined at a predetermined angle with respect to the vertical direction. Inside of the ink cartridge, a preventive member is vertically provided. When the ink level is up to the window, light irradiated from the optical sensor permeates the window. Then, the light passes through the ink and reaches the preventive member. Preferably, the window is inclined approximately 20 degrees with respect to the preventive member. Accordingly, an incident angle of the light that has reached the preventive member is different from an incident angle of the light to the window. Thus, most of the light that has reached the preventive member is absorbed or is reflected by the preventive member in a direction different from the incident direction, so that the light reflected toward the optical sensor can be restricted.

Abstract: To accurately position and fix an ink cartridge on an ink cartridge mounting unit, a first engaging depression is formed in the bottom wall of the ink cartridge and a corresponding protrusion is formed in the mounting unit. Also, an ink supply port is formed in the bottom wall. When the ink cartridge is mounted on the mounting unit, the ink supply port is engaged first with an ink supply channel formed in the mounting unit and fluidly connected to the head unit. Then, the first engaging depression is brought into engagement with the corresponding protrusion in the mounting unit. A second engaging depression is further formed in the top. The engaging pawl of a locking arm engages the second engaging depression when the locking arm locks the ink cartridge to the head unit. Further, a pair of ribs is provided on the rear side wall of the ink cartridge. The ribs oppose each other with a prescribed interval.

Abstract: In a calibration data input process, a carriage 5 is moved toward an ink sensor 19 to a prescribed position while the ink sensor 19 detecting levels of reflected light. Then the amount of reflected light is read for over a range wider than the width of the carriage 5 including a theoretical detecting position P2. An actual detecting position P1 is found based on the level of reflected light. The difference between the theoretical detecting position P2 and the actual detecting position P1 is calculated and is stored as the calibration value ? in a first calibration data memory M1. Accordingly, the actual detecting position P1 is set as P2±?. The calibration value ? is used in a calibration process to calibrate the detecting position, so that the level of reflected light can be detected with accuracy.

Abstract: The invention relates to an ink cartridge wherein a remaining amount of ink can be detected using an optical sensor. The ink cartridge has a window, for detection of an ink remaining amount, that is inclined at a predetermined angle with respect to the vertical direction. Inside of the ink cartridge, a preventive member is vertically provided. When the ink level is up to the window, light irradiated from the optical sensor permeates the window. Then, the light passes through the ink and reaches the preventive member. Preferably, the window is inclined approximately 20 degrees with respect to the preventive member. Accordingly, an incident angle of the light that has reached the preventive member is different from an incident angle of the light to the window. Thus, most of the light that has reached the preventive member is absorbed or is reflected by the preventive member in a direction different from the incident direction, so that the light reflected toward the optical sensor can be restricted.

Abstract: An image forming apparatus which makes an appropriately timed query as to whether or not an ink cartridge has been replaced and performs maintenance which preferably reflects the input from a user to the query. When the upper body of the apparatus which is opened and closed for the replacement of an ink cartridge is opened and then closed, the user is asked which colors of ink cartridges have been replaced, and then whether the cartridge has been replaced by a new ink cartridge. Flushing is performed to un-replaced ink cartridges. A single purge is performed to the ink cartridges which have been replaced by previously used ink cartridges. And a replacement purge is performed to the ink cartridges which have been replaced by new ink cartridges.

Abstract: To accurately position and fix an ink cartridge on an ink cartridge mounting unit, a first engaging depression is formed in the bottom wall of the ink cartridge and a corresponding protrusion is formed in the mounting unit. Also, an ink supply port is formed in the bottom wall. When the ink cartridge is mounted on the mounting unit, the ink supply port is engaged first with an ink supply channel formed in the mounting unit and fluidly connected to the head unit. Then, the first engaging depression is brought into engagement with the corresponding protrusion in the mounting unit. A second engaging depression is further formed in the top. The engaging pawl of a locking arm engages the second engaging, depression when the locking arm locks the ink cartridge to the head unit. Further, a pair of ribs is provided on the rear side wall of the ink cartridge. The ribs oppose each other with a prescribed interval.

Abstract: The invention relates to an ink cartridge wherein a remaining amount of ink can be detected using an optical sensor. The ink cartridge has a window, for detection of an ink remaining amount, that is inclined at a predetermined angle with respect to the vertical direction. Inside of the ink cartridge, a preventive member is vertically provided. When the ink level is up to the window, light irradiated from the optical sensor permeates the window. Then, the light passes through the ink and reaches the preventive member. Preferably, the window is inclined approximately 20 degrees with respect to the preventive member. Accordingly, an incident angle of the light that has reached the preventive member is different from an incident angle of the light to the window. Thus, most of the light that has reached the preventive member is absorbed or is reflected by the preventive member in a direction different from the incident direction, so that the light reflected toward the optical sensor can be restricted.

Abstract: To accurately position and fix an ink cartridge on an ink cartridge mounting unit, a first engaging depression is formed in the bottom wall of the ink cartridge and a corresponding protrusion is formed in the mounting unit. Also, an ink supply port is formed in the bottom wall. When the ink cartridge is mounted on the mounting unit, the ink supply port is engaged first with an ink supply channel formed in the mounting unit and fluidly connected to the head unit. Then, the first engaging depression is brought into engagement with the corresponding protrusion in the mounting unit. A second engaging depression is further formed in the top. The engaging pawl of a locking arm engages the second engaging depression when the locking arm locks the ink cartridge to the head unit. Further, a pair of ribs is provided on the rear side wall of the ink cartridge. The ribs oppose each other with a prescribed interval.