Semiconductor Energy Laboratory Co., Ltd.

Brother Kogyo Kabushiki-kaisha

Masafumi Ito

Tomoaki Atsumi

Tasuku Sugimoto

Hironori Hirata

A brushless motor device configured to: determine a first upper limit of a current value which flows through a coil when a rotation speed of a rotor is accelerated from a first speed to a second speed, wherein, in a case where the current value of the first upper limit flows through the coil when the rotor is rotated at the second speed, a first time period, which is from a start of a non-energization time period of the coil until an induced voltage reaches a threshold value, is longer than a second time period, which is from the start of the non-energization time period until a counter-electromotive voltage becomes zero; and change switching of each switching element of an inverter circuit by using a second upper limit greater than the first upper limit and the first upper limit.

Brushless motor device, image forming apparatus, and control method for controlling brushless motor

An image forming system includes an image forming apparatus, an option device, and a power supply line. The image forming apparatus includes an apparatus controller, an image forming unit, and an apparatus power supply. The apparatus power supply is configured to generate a control voltage that is supplied to the apparatus controller and an apparatus drive voltage that is supplied to the image forming unit. The option device includes a drive load, an option power supply, an option controller, and a detector. The option controller is configured to control the option power supply and receive the control voltage supplied from the apparatus power supply, via the power supply line. The detector is configured to transmit a detection signal to the option controller, the detection signal from among a plurality of different detection signals corresponding to operation statuses of the option power supply.

Image forming system

An image forming system includes an image forming apparatus. The image forming apparatus includes an image forming unit, a housing, an apparatus controller, and an apparatus power supply. The apparatus power supply is configured to generate a control voltage that is supplied to the apparatus controller and an apparatus drive voltage that is supplied to the image forming unit, the apparatus power supply including an output terminal from which the control voltage is outputted. The image forming apparatus includes a first connection terminal, and a second connection terminal. The apparatus controller is configured to transmit a change command via the second connection terminal and change an operation status of the apparatus power supply after the apparatus controller receives information in response to the change command. The image forming system can also include an option device connected to the first and second connection terminals.

An object of the present invention is to provide a CRC circuit with more simple structure and low power consumption. The CRC circuit includes a first shift register to a p-th shift register, a first EXOR to a (p&#x2212;1)th EXOR, and a switching circuit. A data signal, a select signal, and an output of a last stage of the p-th shift register are inputted to the switching circuit, and the switching circuit switches a first signal or a second signal in response to the select signal to be outputted.

Cyclic redundancy check circuit and semiconductor device having the cyclic redundancy check circuit

It is an object to provide a DC/DC converter that can stabilize power supply potential in use. It is another object to provide a semiconductor device in which circuit operation is stabilized. In addition to a power supply that supplies potential to be reference potential of boosting in a DC/DC converter, a power supply for charging a capacitor in the DC/DC converter is provided. Accordingly, loads to the power supply that supplies the reference potential of boosting can be reduced. Further, as power for charging the capacitor in the DC/DC converter, power supplied from not an antenna but a secondary battery is used. More specifically, a secondary battery is used as a power supply that supplies power to a buffer circuit or an inverter circuit. Thus, power supplied from the antenna can be stabilized. In other words, operation of a logic circuit and an analog circuit can be stabilized.

Semiconductor device using DC/DC converter

A memory device that has a function used to continue or disrupt a supply of electric power used to retain data stored in a recording medium or a supply of operating electric power of a circuit used to read out data stored in a storage medium, using personal identification information is provided. When the recording medium is formed of a volatile memory, this memory device has a power supply used to manage a supply of electric power that is used for retention of the stored data using the personal identification information and to retain or erase stored data by continuation or disruption of a supply of electric power by use of the personal identification information.

Growing community of inventors

Okazaki, Japan

Masafumi Ito