A thermal printhead includes a substrate having an obverse surface, a projection formed on the obverse surface and extending in a primary scanning direction, a plurality of heating elements arranged in the primary scanning direction on the top of the projection, a groove dented from the top of the projection and extending in the primary scanning direction, and a heat storage member filling at least an opening of the groove.

According to one embodiment, a thermal print head includes a heat sink; a head substrate placed on the heat sink and having a plurality of heat generating elements arranged in a primary scanning direction; a circuit board placed on the heat sink so as to be adjacent to the head substrate in an auxiliary scanning direction and provided with a connection circuit; and a control element electrically connected to the heat generating element via a first bonding wire and electrically connected to the connection circuit via a second bonding wire, in which at least one of the first bonding wire and the second bonding wire includes any of a copper wire, a copper alloy wire, and a wire mainly made of copper and coated with a metal different from copper.

In accordance with an embodiment, an image forming apparatus comprises a thermal head including a plurality of heat generation elements and configured to form an image on a sheet using heat generated by the heat generation element; a health check section configured to diagnose conditions of the heat generation elements; and a control section configured to control the health check section to execute a health check processing when the thermal head is not executing a job of forming an image and diagnose conditions of remaining heat generation elements in a next health check processing when the health check processing is interrupted.

An asymmetric thermal print head includes a print head body and a plurality of print elements supported on the print head body. The print elements are aligned along a first axis. Each print element includes a heater portion having a burn width measured along the first axis corresponding to a first print resolution, and a burn length measured along a second axis, which is perpendicular to the first axis, corresponding to a second print resolution. The second print resolution is higher than the first print resolution. One or more control circuits are configured to individually activate the print elements.

Certain embodiments provide a thermal print head including: a first heat storage layer formed on a substrate; a heat generator formed on the first heat storage layer; an electrode formed from the first heat storage layer to the substrate and electrically connected to the heat generator; and a barrier layer that covers the electrode and is formed by a CVD method.

According to one embodiment, an image forming apparatus includes a first heating unit, a second heating unit, and a print controller. The first heating unit includes a first heat source that generates heat with alternating current power. The second heating unit includes a second heat source that generates heat with direct current power. The print controller is configured to control printing using either the first heating unit or the second heating unit.

A thermal head includes a substrate, a glaze layer, and a reinforced conductor layer. The glaze includes a first glaze and a second glaze. The first glaze extends in a predetermined direction on the surface of the substrate. The second glaze is spaced part from the first glaze to one side in a direction perpendicular to the predetermined direction on the surface of the substrate. The reinforced conductor layer includes a lateral side part. The lateral side part extends on the surface of the substrate from the first glaze side to the second glaze side and is partially located on the second glaze. An edge part on the first glaze side in the second glaze includes a cutout portion cut out toward the one side in the direction perpendicular to the predetermined direction. The lateral side part passes through the cutout portion.

According to one embodiment, a thermal print head includes a heat sink, a head substrate having a plurality of heat generating elements placed on the heat sink and disposed in a primary scanning direction, a circuit board placed on the heat sink so as to be adjacent to the head substrate in an auxiliary scanning direction and provided with a connection circuit, and a control element electrically connected to the heat generating element via a first bonding wire and electrically connected to the connection circuit via a second bonding wire, wherein a plurality of first bonding wires is disposed in parallel in the primary scanning direction, and among the first bonding wires, the first bonding wire having a length of at least 2 mm or more is a metal wire having a Young's modulus greater than that of gold.

A thermal print head includes: a substrate having an obverse surface; a plurality of heat generators arranged on the substrate in a main scanning direction; and a wiring layer provided on the substrate and constituting an energization path to the heat generators. The substrate has a protrusion protruding from the obverse surface and extending in the main scanning direction. The protrusion has a top portion having the largest distance from the obverse surface, and an inclined portion connected to the top portion in a sub-scanning direction. The inclined portion is inclined relative to the obverse surface at a predetermined angle. Each of the plurality of heat generators extends across a boundary between the top portion and the inclined portion. Each of the heat generators is formed on at least a part of the top portion and at least a part of the inclined portion in the sub-scanning direction.

According to one embodiment, an image forming apparatus includes a first heating unit, a second heating unit, and a print controller. The first heating unit includes a first heat source that generates heat with alternating current power. The second heating unit includes a second heat source that generates heat with direct current power. The print controller is configured to control printing using either the first heating unit or the second heating unit.