A thermal printer of an embodiment includes: a main body; an opening and closing lid; a printing portion that includes a platen and a thermal head; a locking portion locks the opening and closing lid; a detection unit that detects a predetermined pressing state between the thermal head and the platen when a sensor detects a detection target portion; a controller that prohibits printing by the printing portion when the detection unit does not detect the predetermined pressing state; and a biasing member that biases the main body and the opening and closing lid in a direction in which the main body and the opening and closing lid are separated from each other so that the sensor does not detect the detection target portion in a state where the opening and closing lid is not locked to the locking portion.

A thermal printer of an embodiment includes: a main body; an opening and closing lid; a printing portion that includes a platen and a thermal head; a locking portion locks the opening and closing lid; a detection unit that detects a predetermined pressing state between the thermal head and the platen when a sensor detects a detection target portion; a controller that prohibits printing by the printing portion when the detection unit does not detect the predetermined pressing state; and a biasing member that biases the main body and the opening and closing lid in a direction in which the main body and the opening and closing lid are separated from each other so that the sensor does not detect the detection target portion in a state where the opening and closing lid is not locked to the locking portion.

An example apparatus includes a gear comprising a gear hub; a swing-arm rotationally engaged with the gear hub; and a spring circumferentially engaged with the gear hub and the swing-arm to apply a radial clamping force between the swing-arm and the gear hub. Torque is frictionally coupled from the gear hub to the swing-arm to lock a capped print head assembly (PHA) in a non-printing location.

An example apparatus includes a gear comprising a gear hub; a swing-arm rotationally engaged with the gear hub; and a spring circumferentially engaged with the gear hub and the swing-arm to apply a radial clamping force between the swing-arm and the gear hub. Torque is frictionally coupled from the gear hub to the swing-arm to lock a capped print head assembly (PHA) in a non-printing location.

In some examples, an apparatus can include a print substance gauge to indicate a quantity of print particles an imaging device is capable of receiving at a particular time, and an authentication mechanism coupled to a locking mechanism, the authentication mechanism includes instructions to: determine a quantity of print particles within a print particle container, and unlock the locking mechanism when the print substance gauge indicates that the imagining device is capable of receiving the quantity of print particles within the print particle container.

In some examples, an apparatus can include a print substance gauge to indicate a quantity of print particles an imaging device is capable of receiving at a particular time, and an authentication mechanism coupled to a locking mechanism, the authentication mechanism includes instructions to: determine a quantity of print particles within a print particle container, and unlock the locking mechanism when the print substance gauge indicates that the imagining device is capable of receiving the quantity of print particles within the print particle container.

Provided is an image forming system capable of reliably preventing others from removing and taking printed matter even though printing is executed beforehand. The confidential notation reading unit reads a confidential notation. The user storage tray has a structure from which outputted printed matter cannot be removed unless the opening/closing door is opened. The locking mechanism locks the opening/closing door. The sorting mechanism sorts the printed matter outputted from the image forming apparatus and outputs the printed matter to either the open tray or the user storage tray. The sorting control unit outputs printed matter to which a confidential notation is not added to the open tray, and outputs a printed matter to which a confidential notation is added to the user storage tray, respectively.

Provided is an image forming system capable of reliably preventing others from removing and taking printed matter even though printing is executed beforehand. The confidential notation reading unit reads a confidential notation. The user storage tray has a structure from which outputted printed matter cannot be removed unless the opening/closing door is opened. The locking mechanism locks the opening/closing door. The sorting mechanism sorts the printed matter outputted from the image forming apparatus and outputs the printed matter to either the open tray or the user storage tray. The sorting control unit outputs printed matter to which a confidential notation is not added to the open tray, and outputs a printed matter to which a confidential notation is added to the user storage tray, respectively.

An example apparatus includes a gear comprising a gear hub; a swing-arm rotationally engaged with the gear hub; and a spring circumferentially engaged with the gear hub and the swing-arm to apply a radial clamping force between the swing-arm and the gear hub. Torque is frictionally coupled from the gear hub to the swing-arm to lock a capped print head assembly (PHA) in a non-printing location.

An example apparatus includes a gear comprising a gear hub; a swing-arm rotationally engaged with the gear hub; and a spring circumferentially engaged with the gear hub and the swing-arm to apply a radial clamping force between the swing-arm and the gear hub. Torque is frictionally coupled from the gear hub to the swing-arm to lock a capped print head assembly (PHA) in a non-printing location.