Minolta Camera Kabushiki Kaisha

Minolta Company, Ltd.

Makoto Sekiya

Yoshikazu Ikenoue

Kiyoshi Emori

In a system including a controller and peripherals connected to the controller, a plurality of statuses represents states of each of the peripherals. Most general statuses useful for controlling the peripheral are taken as statuses in a highest layer of a tree structure, and it is branched to statuses of lower layers successively. When a signal of a certain status, which has no lower statuses which branches further therefrom, signals of the statuses between the certain status and the most general status relevant to the certain status are changed successively. Simultaneously, the information of the statuses on which the signals are changed is transmitted to a controller. Thus, the status information can be transmitted surely to the controller.

Status management and data transmission in a system comprising

When a front cover of a body of a printer is opened, a count value in a system RAM included in a printer body control processor is recorded in a counter in an E.sup.2 PROM included in a process cartridge through a system bus and an input/output port. On the other hand, when the front cover of the printer body is closed, a count value of the E.sup.2 PROM is recorded in the counter in the system RAM. Even in the case where a main switch is turned off, electric power from a receptacle is supplied to each control circuit through a transformer.

Image forming apparatus which stores counted value in different memories

A counter has a memory which stores at least three continuous numerical values and a controller which rewrites a lowest numerical value to a numerical value obtained by adding 1 to a largest numerical value within said continuous numerical values stored in the memory and discriminates whether or not said numerical values stored in the memory are continuous to judge a count error. When said numerical values stored in the memory are not continuous, the noncontinuous numerical value is corrected by adding 1 to the largest value of other continuous numerical values stored in said memory.

Counter

A control apparatus for controlling a printer in which a memory for memorizing data to be printed is sent from an external processor and a capability for deleting data memorized in the memory is provided. Data in memory is deleted according to a control code sent from the external data processor or entered through an operation panel. A range of data to be deleted is determined based on a control code given.

Control apparatus for a printer

When a data control portion 300 receives a request for changing a density of picture elements from an external data processing apparatus, a printing control portion 200 defers exposure if it is before start of exposure, until a rotating speed of a polygon mirror 34 becomes constant. If exposure is being performed, the printing control portion 200 defers change of the density of picture elements until the exposure is completed. If printing is being performed in response to a printing request received till then, the printing control portion 200 defers change of the density of the picture elements until the printing is completed. In addition, the printing control portion 200 automatically sets an initial density value of picture elements designated by a printing density initialization switch 237, when power supply is turned on.

Printing apparatus with plural density control

An improved laser printer having a density sensor which reads a density of an automatic image density control (AIDC) mark formed outside an image area on a photoconductor 2. A CPU controls a solenoid based on an output of the density sensor and regulates the amount of toner supply to a developing device. A start counter and an end counter define a start position and an end position in both the primary scanning direction of the image area and in the main scanning direction of the AIDC mark. The start and end positiones are based on timer values set in their respective counters.

Laser printer with toner image density control

A data communication system for the communication between two different data transmission systems, the SDT system and the RDT system. The SDT system includes a host CPU having an output terminal for repeatedly producing first data in a predetermined sequence of time slots by a number of interruptions taken in each time slot, a bus structure extending from the output terminal of the host CPU for transmitting the data, and a plurality of slave CPUs, each having an input terminal connected to the bus structure for receiving the first data. The RDT system for the data transmission between at least first and second CPUs includes a RAM for storing a command to the second CPU. The first CPU is operative to write the command into the RAM. The first command writing takes place at a first predetermined pulse period in a predetermined sequence of pulses. The second CPU reads the command from the RAM at a second predetermined pulse period. The host CPU in the SDT system is used in common with the first CPU in the RDT system. Also, the sequence of time slots have at least one time slot which is sufficiently long to include the sum of one cycle of the predetermined sequence of pulses and one pulse period for carrying out the data transmission by the second data transmission system within one time slot.

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Toyokawa, Japan

Makoto Sekiya