Abstract: A signal transmission device includes a communication unit that performs communication using differential transmission with an electronic device via a differential wiring, and a signal processing unit that performs signal processing related to the communication, in which the communication unit is capable of receiving, via the differential wiring, communication signals transmitted from the electronic device at each of a plurality of signal transmission rates including at least a first signal transmission rate and a second signal transmission rate lower than the first signal transmission rate, the communication unit measures an amplitude of the communication signals received from the electronic device at the second signal transmission rate, and the signal processing unit detects a short-circuit failure of a filter circuit on the basis of the amplitude measured by the communication unit.

Abstract: A battery authentication system includes a battery pack, and a host device connected to the battery pack to charge the battery pack. The battery pack includes a battery, a discharge switch that turns on and off discharging of the battery, a charge switch that turns on and off charging of the battery, and a control integrated circuit (IC) that controls the battery. The control IC includes a charge/discharge control circuit that controls the discharge switch and the charge switch, and an authentication circuit that performs a process for performing an authentication with the host device. The authentication circuit is configured to perform a process associated with a first authentication. The charge/discharge control circuit is configured to control the discharge switch to be turned on when the first authentication is established. The authentication circuit is configured to perform a process associated with a second authentication.

Abstract: A battery authentication system includes a battery pack, and a host device connected to the battery pack to charge the battery pack. The battery pack includes a battery, a discharge switch that turns on and off discharging of the battery, a charge switch that turns on and off charging of the battery, and a control integrated circuit (IC) that controls the battery. The control IC includes a charge/discharge control circuit that controls the discharge switch and the charge switch, and an authentication circuit that performs a process for performing an authentication with the host device. The authentication circuit is configured to perform a process associated with a first authentication. The charge/discharge control circuit is configured to control the discharge switch to be turned on when the first authentication is established. The authentication circuit is configured to perform a process associated with a second authentication.

Abstract: It is possible to limit the use of non-authentic battery packs. A battery control IC (200) includes an authentication circuit (208) and a charge/discharge control circuit (210). The charge/discharge control circuit (210) controls charging and discharging of a battery (22). The authentication circuit (208) performs a process for performing an authentication with a host device. The authentication circuit (208) is configured to perform a process associated with a first authentication in a common key system. The charge/discharge control circuit (210) is configured to perform a control to enable a discharge operation when the first authentication is established.

Abstract: It is possible to limit the use of non-authentic battery packs. A battery control IC (200) includes an authentication circuit (208) and a charge/discharge control circuit (210). The charge/discharge control circuit (210) controls charging and discharging of a battery (22). The authentication circuit (208) performs a process for performing an authentication with a host device. The authentication circuit (208) is configured to perform a process associated with a first authentication in a common key system. The charge/discharge control circuit (210) is configured to perform a control to enable a discharge operation when the first authentication is established.

Abstract: In the CAV recording, it is necessary to vary the recording-system clock frequency in accordance with movement of a recording position, and conventionally a signal generated by multiplying a wobble signal is used as the recording-system clock. However, since the wobble signal is easily susceptible to influences of a disk and a pick-up and its quality is prone to be deteriorated by an influence of a large amount of light at the time of recording etc., it is difficult to maintain jitters of the recording-system clock to a sufficiently low value. To resolve this problem, instead of generating a recording-system clock signal from the wobble signal that is susceptible to noise, a necessary recording-system clock frequency is calculated from the address information that has been modulated into the wobble signal and recorded therein, and a signal of this frequency is generated from a stable reference signal source, such as a quartz oscillator, by a synthesizer method and used as the recording-system clock.

Abstract: The present invention provides a technology for increasing the recording system clock speed for high-speed information recording onto an optical disk or the like without sacrificing the frequency resolution. A necessary recording system clock frequency is calculated from address information that is modulated by a wobble signal and recorded. A crystal oscillator or other stable reference signal source generates a signal having the calculated frequency by a synthesizing method. The generated signal is used as a recording system clock.

Abstract: In the CAV recording, it is necessary to vary the recording-system clock frequency in accordance with movement of a recording position, and conventionally a signal generated by multiplying a wobble signal is used as the recording-system clock. However, since the wobble signal is easily susceptible to influences of a disk and a pick-up and its quality is prone to be deteriorated by an influence of a large amount of light at the time of recording etc., it is difficult to maintain jitters of the recording-system clock to a sufficiently low value. To resolve this problem, instead of generating a recording-system clock signal from the wobble signal that is susceptible to noise, a necessary recording-system clock frequency is calculated from the address information that has been modulated into the wobble signal and recorded therein, and a signal of this frequency is generated from a stable reference signal source, such as a quartz oscillator, by a synthesizer method and used as the recording-system clock.

Abstract: A method for correcting a recording head is provided to solve the problems of density unevenness in recorded images. The density comparison is made with the reference density for a predetermined unit in the density distribution of an image recorded by the application of n kinds of signals. Then, one of the n kinds of signals which is close to the reference density is selected. The properties of the signal thus selected are transmitted to the recording head together with the correction data, hence correcting density unevenness.