A data storage device is disclosed comprising a first head actuated over a first disk surface, wherein the first head comprises a laser configured to heat the first disk surface while writing data to the first disk surface. A write power is applied to the laser and a first write operation is executed to write first data to the first disk surface during a first revolution of the first disk surface. A first transient decrease in an output power of the laser is detected during the first write operation, and when the first transient decrease in the output power of the laser is detected during the first write operation, a write-verify of the first data is executed during a second revolution of the first disk surface.

A system includes a multiplexed optical identifier and a reader for the optical identifier. The multiplexed optical identifier includes an optical substrate, and a plurality of volume holograms in the optical substrate. The reader includes an illumination source and a camera. The illumination source is configured to direct light into the optical identifier to produce an image of a corresponding one of the volume holograms at the camera, and the camera is configured to capture the image, which is stored in a digital format by the system. The multiplexed optical identifier contains more than one code page, wherein each of the code pages is used for a different purpose.

A data delay circuit, for delaying a portion of a data signal for application to a write head of a hard disk drive, includes a data delay cell including two inverters and a charge current source for charging at least one of the inverters, and a bias circuit for programming delay of the data delay cell. The bias circuit is in current-mirroring relationship with the charge current source and includes a current-based digital-to-analog converter (DAC) for programmably selecting the delay of the data delay cell, and a reference current source for the DAC. The data delay cell and the bias circuit are subject to gain error, and the data delay circuit further includes compensation circuitry for reducing the effect of the gain error. The compensation circuitry may include replica charge current and reference current sources that are fed back through a gain cell.

A data storage device may include one or more disks, an actuator arm assembly comprising one or more disk heads, at least one laser diode positioned inside a corresponding laser diode cavity, a preamplifier, and one or more processing devices. The one or more processing devices are configured to: generate a reverse bias; apply, using the preamplifier, the reverse bias to the at least one laser diode to preheat a corresponding laser diode cavity to a target temperature prior to a write operation; control transition of the preamplifier from applying the reverse bias to applying a forward bias to the at least one laser diode; and activate the at least one laser diode to begin the write operation.

A rotating magnetic physical unclonable function (PUF) is disclosed. Rotating the PUF enables robust low cost PUF readers. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other systems and methods are disclosed.

A rotating magnetic physical unclonable function (PUF) is disclosed. Rotating the PUF enables robust low cost PUF readers. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other systems and methods are disclosed.

According to one embodiment, a system for processing data includes a controller configured to determine whether a position error signal (PES) is invalid while reading data from a magnetic medium using at least one data channel. The controller is also configured to determine whether a PES value is above a first predetermined threshold in response to a determination that the PES is valid. Moreover, the controller is configured to inject error bits into a data stream in place of corresponding bits of decoded data in response to a determination that the PES is invalid and in response to a determination that the PES value is above the first predetermined threshold. Other systems and methods for processing data are described in accordance with more embodiments.

A preamplifier circuit can include a control line dedicated to receive a control signal that corresponds to indicating a specific register of the preamplifier circuit, which can allow the preamplifier to switch between utilizing two or more registers to control a current output of the preamplifier circuit. The preamplifier circuit may also have a serial input to program multiple registers of the preamplifier circuit in a serial fashion. In some embodiments, the current output may be a laser bias current. The preamplifier may adjust an output current that drives a laser emitter based on a control signal indicating which specific registers controls the output current. Further, a controller, such as a system-on-chip controller, may selectively vary the control signal to affect the current output of the preamplifier circuit. These systems and methods may be particularly useful for lasers and heat-assisted magnetic recording (HAMR).

A suspension board with circuit includes a metal supporting layer, a base insulating layer, a conductive pattern including a wire, and a cover insulating layer. The conductive pattern includes a terminal for being connected to a piezoelectric element, connected to the wire, and disposed next to the base insulating layer in a direction perpendicular to the thickness direction. The terminal is exposed from the metal supporting layer and the base insulating layer when viewed from the other side in the thickness direction, and extends along the direction perpendicular to the thickness direction so as to go away from the base insulating layer next thereto. At least a portion of a peripheral end surface of the terminal is covered with the cover insulating layer.

Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position one or more heads proximate to a corresponding disk surface of the one or more disks; and one or more processing devices. The selected head comprises a write element and an assistive energy emitter. The one or more processing devices are configured to apply an assistive energy current to the assistive energy emitter while refraining from applying a write current to the write element.