JPH0666419B2 - Printer LSI - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a printer LSI that is applied to an LSI for a control circuit of a printer such as a laser beam printer, a thermal printer, and a dot printer.

[Technical background of the invention and its problems]

The control circuit of a conventional laser beam printer has been miniaturized by using a microcomputer, but for example, about 40 individual ICs are required for the control circuit between the host interface, the mechanical control unit and the microcomputer. However, it has been a major obstacle to realizing a lighter, thinner, smaller, and smaller laser beam printer control unit.

[Object of the Invention]

The present invention solves the above-mentioned problems of the prior art, and aims to make the control unit of a laser beam printer, etc. lighter, thinner, shorter, and smaller, and at the same time improve the reliability and reduce the cost.
The purpose is to provide.

[Outline of Invention]

The printer LSI according to the present invention includes an interface for controlling data transmission / reception with a CPU chip, a host interface connected with this interface for controlling data transmission / reception with a host, and a mechanical device inside the printer connected with this host interface. And a mechanical control interface, and a counter connected between the interface and the mechanical control interface for controlling print data and the like, and a logic circuit including these units is configured in one semiconductor integrated circuit. The functions such as the host interface section, print data control section, timer section, test printing function, and microcomputer transmission / reception functions are integrated into a gate array, and the number of input / output pins also corresponds to the operation confirmation signal of the internal circuit. Output with data selector, 46-pin DIP By storing it in a package, the control function of a laser beam printer, etc. can be provided with a few chips including a microcomputer, ROM and RAM, and the control unit can be made lighter, thinner, shorter, and more reliable, and the cost can be reduced. It's something I got to get.

Example of Invention

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention, in which 1 is an interface for controlling data transmission / reception with a CPU chip, for example, a microcomputer interface, 2 is connected to a microcomputer interface 1, and data transmission / reception with a host is performed. Is connected to the host interface 2, a mechanical control interface for controlling mechanical devices inside the printer is connected between the microcomputer interface 1 and the mechanical control interface 3, and for example, a printing area, This is a counter having a counting circuit mainly composed of a laser beam cueing counter, a test printing pattern generating counter, and the like, and mainly controlling print data, and the like. Configured as a semiconductor integrated circuit It has been.

The microcomputer interface 1 has a function of interfacing between the 8085A CPU chip and the printer LSI according to the present invention, for example, has an internal register address allocation, data transmission / reception, and lower address latching function, and transmits / receives data to / from the CPU. Is to do.

The host interface 2 transmits / receives data to / from the printer such as a PC word processor, transmits printer status, receives print data (this reception is parallel data 8 bits, serial data synchronous type, serial data asynchronous type), etc. Has the function of performing.

The mechanical control interface 3 is, for example, a laser beam ON
This is an interface for transmitting / OFF, drive of motors, etc., and inputs of various sensors to the CPU chip.

The counter 4 determines the printable area of the printer (A4, A3, etc. for cut paper), counts from the scanning start point to the end point of the laser beam, etc., and from the counting circuit for generating print patterns when performing test printing. It is configured and mainly controls print data.

FIG. 2 is a block diagram showing a schematic structure of a printer using the printer LSI according to the present invention, and 10 is the printer LSI according to the present invention, which is composed of the respective units 1 to 4 in FIG. 11 is a CPU, 12 is a ROM, 13 is a RAM, and 14 is an additional input / output port. In FIG. 2, the configuration and function of each unit other than the printer LSI 10 are the same as those of the conventional one, and therefore the description thereof is omitted.

The operation of the embodiment of the present invention will be described. In FIG. 1, the CPU chip checks the inside of the printer via the mechanical control interface 3 to determine the presence or absence of the above, and outputs the status to the host via the host interface 2 and at the same time displays it on the display on the console.

If there is no abnormality, the CPU chip transmits that printing is possible to the host via the microcomputer interface 1 and the host interface 2, and waits for data reception from the host.

Since the CPU chip knows in advance via the mechanical control interface 3 whether the print data sent to the host interface 2 is parallel data or serial data, it controls the data reception according to each, and when it is serial data. Determines whether it is a synchronous type or an asynchronous type via the mechanical control interface 3.

The CPU confirms that the received print data is within the print area.
When the chip judges from the counter 4 via the microcomputer interface 1, it controls ON / OFF of a laser beam or the like as serial data. At the same time, the laser beam is scanned for one line, and when the printing for one line is completed, the paper feed is controlled, and the drum, the heater, etc. are also controlled. In this case, the control of the paper feed, the drum, the heater, etc. is performed via the input / output port (corresponding to 14 in FIG. 2) arranged outside the printer LSI 10 (FIG. 2).

When all printing is completed, the paper is ejected and the printing operation is completed.

Note that, for example, when it is necessary to print in a state where there is no connection to the host for printer failure diagnosis, maintenance adjustment, etc., test printing is performed with a switch from the console.

In this case, when the CPU chip knows that the test switch on the operation table has been pressed, a test print pattern of the counter 4 is generated via the microcomputer interface 1 and the laser or the like is turned ON / OFF according to this pattern. .

In addition, although the case where the invention is applied to the laser printer has been described in the above-described embodiment of the present invention, the present invention is not limited to the above-described embodiment, and a thermal transfer printer, a serial dot printer, a heat-sensitive printer, or the like is also applicable. Needless to say, the same applies.

〔The invention's effect〕

As described above, according to the present invention, by converting the function of the conventional individual IC around the CPU chip into an LSI as described above,
It is possible to reduce the electronic components of the conventional printer to about 1/3. For example, by using a 64-pin shrink DIP for the LSI package according to the present invention, the area occupied by the LSI can be reduced and a single board can be realized. The printer control unit can be made lighter, thinner, shorter and smaller, cost can be reduced, reliability can be improved, and confidentiality can be maintained and maintenance parts can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention, and FIG. 2 is a block diagram showing an outline of a printer using the printer LSI shown in FIG. 1 ... Microcomputer interface, 2 ...
Host interface, 3 ... Mechanical control interface, 4 ... Counter, 10 ... Printer LSI.

Claims (1)

[Claims] 1. An interface for controlling data transmission / reception to / from a CPU chip, connected to the interface,
A host interface that controls data transmission / reception with a host, a mechanical control interface that is connected to the host interface and controls a mechanical device inside the printer, and is connected between the interface and the mechanical control interface to control print data and the like. An LSI for a printer, comprising a counter for performing the above operation, and a logic circuit including these units is configured in one semiconductor integrated circuit.