An image processing device includes a modulation clock generator, a line synchronization signal generator, a line image sensor, and an image processor. The modulation clock generator is configured to generate the modulation clock by modulating a frequency of a reference clock at a predetermined modulation cycle. The line synchronization signal generator is configured to generate, on the basis of the modulation clock, a line synchronization signal whose line cycle varies from line to line. The line image sensor is configured to sequentially read an image of one line of a document at a timing corresponding to the line synchronization signal and to output image data. The image processor is configured to process the image data on the basis of the modulation clock.

An information processing apparatus includes: a first unit as a main body of the information processing apparatus; a second unit openable and closable relative to the first unit; a third unit openable and closable relative to the second unit; and a controller programmed to control operations of the first unit. The second unit includes a first detector configured to detect whether the third unit is opened or closed relative to the second unit. When the second unit is in an opened position relative to the first unit, the first detector detects that the third unit is opened. The controller controls at least one of the first unit, the second unit, and the third unit based on a result of the detection by the first detector.

A data processing device includes a data processing circuit and a data processing control circuit. The data processing circuit is configured to perform data processing on processing target data by use of an external clock, the processing target data being included in a data signal received from an outside, the external clock being included in the data signal. The data processing control circuit is configured to detect a state of the external clock and control execution of the data processing on the processing target data in accordance with the state of the external clock. The data processing control circuit is configured to operate with a clock having a lower impedance than an impedance of the external clock, and discard the processing target data received during a period in which an abnormality of the external clock is detected, in a case of detecting the abnormality of the external clock.

An image signal processing device includes a reference signal generating portion, a determination portion, and an extraction portion. The reference signal generating portion generates and outputs a reference signal that sequentially transmits reference pulses shifted from horizontal synchronization pulses on a horizontal synchronization signal by a predetermined shift time. The determination portion determines whether the horizontal synchronization pulses are normal by comparing time differences between input of the horizontal synchronization pulses and input of the reference pulses with the shift time. The extraction portion extracts line image data points from an image signal in synchronization with the input of the horizontal synchronization pulses that have been determined as normal.

An information processing device includes a first input interface to receive data transferred in a first transfer mode in which a plurality of elements of the data each belonging to a same line of a plurality of lines are transferred in parallel, a second input interface to receive data transferred in a second transfer mode in which a plurality of elements of the data each belonging to a corresponding one of the plurality of lines are transferred in parallel, a mode selection circuit to change a transfer mode of the data from the second input interface from the second transfer mode to the first transfer mode based on a signal indicating selection of the second input interface, and an output interface to output one of the data from the first input interface and the data from the second input interface.

An image forming apparatus has a clock supply circuit supplying a signal at a first clock frequency or a second clock frequency lower than the first frequency, a first CPU performing image data processing based on the signal, and a second CPU measuring time based on the signal to determine execution timing of each process performed in control processing. The image forming apparatus includes a load determination unit determining whether a load of the image data processing is higher than a reference level, and a control unit that switches the frequency to the first frequency when the load is higher than the reference level, and to the second frequency when the load is not higher. When the frequency switching occurs, the second CPU changes a method for measuring time. The second CPU completes one process before the switching and starts the next one after the switching.

An information processing system includes an information processing apparatus and a server. A acquisition unit of the apparatus acquires a first screen. A display unit of the apparatus displays the first screen. When a button to which an instruction is attached is pressed, a determination request information transmission unit of the apparatus transmits, to the server, determination request information requesting a validity determination to determine whether the application associated with the instruction can be used in the information processing apparatus. A reception unit of the apparatus receives, from the server, determination result information. When the determination result information indicates that the application associated with the instruction cannot be used, a first control unit of the apparatus performs control to update firmware. A determining unit of the server performs the validity determination. A determination result information transmission unit of the server transmits the determination result information to the information processing apparatus.

An image processing system includes: a first processor that is mounted on an image processing apparatus including at least one of an image forming unit that performs processing of forming an image on a medium or an image scanning unit that performs processing of scanning an image on a medium; and a second processor that is mounted on a control apparatus that is connected to the image processing apparatus via a virtual leased line, and controls a part of at least one of the processing of forming an image on a medium or the processing of scanning an image on a medium performed by the image processing apparatus, in which the first processor is configured to: control a timing of connection using the virtual leased line with the control apparatus according to a function used by a user among functions of the image processing apparatus.

An image reading apparatus includes a first reading section configured to read a first plane of the document, a second reading section configured to read a second plane which is a back side of the first plane, a first controller stops the reading of the first reading section after causing the first reading section to read a last line before the reading of the first reading section is stopped and transmits a reading stop instruction to a second controller earlier than a timing when the first reading section reads the last line by a time difference corresponding to a delay generated in communication between the first and second controllers. The second controller stops reading of the second reading section after causing the second reading section to read one line in response to the reading stop instruction.

In a case where a temperature detected by a detector is greater than a threshold, one or more processors controls a light source not to emit light and stops conveyance of a document by a conveyance unit. In a case where a predetermined amount of time has elapsed from when the one or more processors controls the light source not to emit the light, the one or more processors controls the light source to emit the light and starts conveyance of the document by the conveyance unit, regardless of a detection result of the detector.