JP2964470B2 - Printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus, and in particular, to an interface unit having an interface capable of receiving transmission data transmitted from an external device, which is arbitrarily increased or decreased according to the number of connected external devices. Related to what can be provided.

[0002]

2. Description of the Related Art Conventionally, printers such as a thermal printer and a laser printer usually receive serial or parallel data transmitted from an external device such as a personal computer or a word processor. Each has an interface for data.

When one printer is shared with several external devices that can transmit serial data, for example, one common connector for connecting to the printer and several external devices are used. Prepare a transfer line switch with several terminal connectors for connecting to external devices,
While connecting the common connector of the switch and the serial data interface of the printer with a connection cable, connecting the terminal connector and the serial data interface of the external device with a connection cable, respectively, the changeover switch of the switch Is selected to switch the data transfer line between the printer and one selected external device.

[0004]

As described above, when one printer and several external devices are connected via a transfer line switch, the number of external devices that can be connected to the printer in a switchable manner is limited. However, there is a problem that the number of terminal connectors of the switching device is limited.

It is also conceivable to increase the number of external devices that can be connected in a switchable manner by combining two or three transfer line switches, but the operation of selecting the switch of these switches becomes complicated. There is a problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an interface unit capable of receiving transmission data from an external device arbitrarily in accordance with the number of external devices to be connected, and an interface unit corresponding to the data-transmitted external device. It is an object of the present invention to provide a printing device that can automatically select a printer.

[0007]

As shown in the functional block diagram of FIG. 1, a printing apparatus according to the present invention receives transmission data including print data transmitted from an external device capable of transmitting data and prints the data on a print medium. In a printing device for printing, a connector for connecting to an external device via a connection cable,
An interface for receiving transmission data via a connector, a latch circuit for receiving and latching parallel data including the transmission data and the interrupter signal from the interface, and a plurality of latch circuits corresponding to a plurality of latch signal output terminals of a controller of the printing apparatus Identification switches, a latch signal line connecting output terminals of these identification switches to a common gate terminal of the latch circuit, and an output terminal group of the latch circuit connected to a transmission data input terminal group of a controller of the printing apparatus; A printer is provided with a plurality of interface units each including a connector for connecting input terminals of a plurality of identification switches to a plurality of latch signal output terminals of a controller of the printing device, and the plurality of interface units are provided with a plurality of latch signals. Set each interface so that it corresponds to each output terminal. One of a plurality of the identification switch of Suyunitto is obtained by short-circuited.

[0008]

In the printing apparatus according to the present invention, each of the plurality of interface units provided in the printing apparatus is connected to an external device via a connection cable. Moreover, only one of the plurality of identification switches of each interface unit is short-circuited so that the plurality of interface units respectively correspond to the plurality of latch signal output terminals of the controller of the printing apparatus. Therefore, when the transmission data from any external device is received, the interface of the interface unit that has received the transmission data transmits the parallel data including the transmission data and the “H” level interrupter signal to the input terminals of the latch circuit. While supplying data, the controller of the printing device first outputs a latch signal to each of the plurality of latch signal output terminals sequentially. As a result, in each interface unit, when a latch signal is input to the latch signal output terminal corresponding to the shorted identification switch, the latch signal is transmitted through the latch signal line connected to the output terminal of the identification switch. The latch circuit, which is supplied to the common gate terminal and receives the latch signal, outputs the parallel data supplied to the input terminal group to the transmission data input terminal group of the controller. Where the controller is
When an "H" level interrupter signal is detected,
It is determined that data has been transmitted to one interface unit corresponding to one latch signal output terminal that outputs a latch signal among the plurality of latch signal output terminals, and the latch signal is continued to this latch signal output terminal. When the latch circuit receives the latch signal, the latch circuit sequentially outputs the transmission data and the interrupter signal supplied to the input terminal group to the transmission data input terminal group of the controller.

[0009]

According to the printing apparatus of the present invention, a plurality of interface units each including an interface, a latch circuit, a plurality of identification switches and connectors are provided in the printing apparatus, as described in the paragraph of [Function]. Therefore, a plurality of interface units can be provided by arbitrarily increasing or decreasing according to the number of external devices connected via the connection cable. Further, since only one of the plurality of identification switches of each interface unit is short-circuited so that the plurality of interface units respectively correspond to the plurality of latch signal output terminals of the controller of the printing apparatus, a latch signal is output from the controller. The specific interface unit that has received the transmission data can be automatically selected based on the output latch signal output terminal and the received "H" level interrupter signal.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment is an embodiment in which the present invention is applied to a laser printer that prints print data transmitted from an external device such as a personal computer or a workstation, as shown in FIGS. First, since the laser printer LP is the same as a general one, a brief explanation will be given. In the main body frame 1 of the laser printer LP, a laser scanner (not shown), a process cartridge 2 (see FIG. A transfer / separation device equipped with a heater and a static elimination needle, a fixing device equipped with a heating roller and a pressure roller, and a transport device equipped with a paper feed roller, a registration roller, a transport roller, a discharge roller, etc. Have been. An operation panel 62 is provided in the laser printer LP.

The process cartridge 2 will be briefly described with reference to FIG. 4. An electrostatic latent image is formed on the peripheral surface of the photosensitive drum 4 to which the high voltage of the charger 3 is applied by the laser scanner. Is done. This electrostatic latent image is developed by the supplied toner, and is transferred onto a recording sheet P conveyed from the sheet feeding mechanism 10 in synchronization with the rotation of the photosensitive drum 4. Thereafter, the recording paper P is discharged to the discharge tray 5 via the fixing device.

Next, a paper feed mechanism 10 provided inside the main body frame 1 of the laser printer LP will be described with reference to FIGS.
It will be described based on FIG. The paper feed mechanism 10 basically includes a paper feed cassette 11 capable of storing a plurality of recording papers P, a paper feed roller 12 for transporting the recording papers P in the paper supply cassette 11 to the process cartridge 2, and a paper feed roller 12. Roller 13
, A driving motor M, a first gear mechanism 20 for transmitting the driving force of the driving motor M to the sheet feeding roller 12 and the conveying roller 13, and a second gear for transmitting the driving force to the sheet feeding unit 40 provided on the lower side. And a mechanism 35.

The paper feed cassette 11 contains the transport rollers 1
3, a conveying roller 15 for conveying the recording paper P to the process cartridge 2, a compression spring 16 for elastically pressing the front end of the recording paper P against the paper feeding roller 12, and a paper feeding roller 12. A guide wall portion 17 having a guide surface for guiding the fed recording paper P to the transport roller 13 in an inclined manner is provided. The guide wall portion 17 is formed with a transport passage 18 having a rectangular cross section through which the recording paper P transported from the paper feed unit 40 additionally provided on the lower side can pass. still,
A rectangular opening 19 corresponding to the transport passage 18 is formed in the bottom wall of the main body frame 1. A paper detection sensor 43 composed of a light emitting element and a light receiving element is attached to the support plate 14 that supports the recording paper P. When the paper detection sensor 43 is detecting the recording paper P, it has an “H” level. A paper detection signal is output, and when the recording paper P runs out, an "L" level paper detection signal is output.

The paper feed roller 12 is formed by a notched cylindrical rubber roller which is partially cut out. When the paper feed roller 12 rotates, the corner 12a and a friction separating member (not shown) cooperate to form a paper feed cassette. Only one sheet of recording paper P is fed to the pair of transport rollers 13 and 15 via the guide surface. Therefore, the fed recording paper P is transported by the transport rollers 13.
By the rotation of 5, the sheet is conveyed to the process cartridge 2.

The first gear mechanism 20 and the second gear mechanism 35 are provided in the right side box 1a of the laser printer LP. The first gear mechanism 20 includes the paper feed roller 1
An intermittent gear 22 fixed to a second roller shaft 21 and partially cutout teeth; a transmission gear 24 fixed to a roller shaft 23 of the transport roller 13; a second gear while meshing with the transmission gear 24; An intermediate gear group 25 meshed with a transmission gear 36 of the mechanism 35 and a clutch mechanism 26 for intermittently transmitting the driving force from the intermediate gear group 25 to the intermittent gear 22 are provided. On the other hand, the drive gear 27 fixed to the drive shaft of the motor M is connected to one of the intermediate gear groups 25 through the intermediate gear 28.
Gears.

The clutch mechanism 26 will be described. A cam 29 is fixed to the gear shaft of the intermittent gear 22, and the cam 29 is locked so that the upper end of the locking lever 30 is always locked to the step 29a. The lever 30 is a tension spring 31
5, a solenoid 32 is provided to release the engagement of the locking lever 30 with the step portion 29a when the recording paper P is fed. Therefore, when the solenoid 32 is not driven,
When the intermittent gear 22 is not rotated through the engagement between the locking lever 30 and the stepped portion 29a and the solenoid 32 is driven, the engagement between the locking lever 30 and the stepped portion 29a is released and the intermediate gear The rotation of the group 25 is transmitted to the intermittent gear 22, and the paper feed roller 12 is rotated.

The second gear mechanism 35 is composed of two transmission gears 36 arranged vertically and meshing with each other. The upper transmission gear 36 is connected to the intermediate gear group 25.

Therefore, when the motor M is rotated in the counterclockwise direction, the intermediate gear group 25 is rotated via the drive gear 27 and the intermediate gear 28, and at the same time, the transmission gear 24, that is, the transport roller 13, is rotated. With the second gear mechanism 35
Are rotated. Reference numeral 37 denotes a concave portion formed in the main body frame 1 so as to be able to engage with the convex portion 42 of the sheet feeding unit 40 which is additionally provided on the lower side. Also,
An interface unit 63 is provided in the side box 1a.

Next, two paper feed units 40 added below the laser printer LP will be described with reference to FIGS. Since these paper feed units 40 are the same, only the upper paper feed unit 40 will be described. However, these paper feed units 40 are provided with side boxes 41a corresponding to the side boxes 1a, in which the first drive mechanism 20, the second drive mechanism 35A, and the interface units 64 and 65 are provided. Each is provided.

The paper supply unit 40 includes a cassette case 41
And a paper feed cassette 10A detachably mounted in the cassette case 41, and a paper feed mechanism 10A for feeding the print paper P one by one from the paper feed cassette 11. The paper cassette 11 and the first gear mechanism 20 are the same as those provided in the laser printer LP.

The paper feed mechanism 10A is the same as the paper feed mechanism 1 described above.
0, but the drive motor M and the intermediate gear 28 are omitted. Further, the second gear mechanism 35A is substantially the same as the above-described second gear mechanism 35, but includes four transmission gears 3A.
6 are vertically arranged and meshed with each other, and the upper transmission gear 36 is meshed with the lower transmission gear 36 of the second gear mechanism 35. Note that a rectangular opening 19 corresponding to the transport passage 18 is formed in the bottom wall of the cassette case 41. Accordingly, each transmission gear 36 of the second gear mechanism 35 is rotated by the driving of the motor M, and at the same time, each transmission gear 36 of the second gear mechanism 35A is rotated.
Is rotated, and each gear of the first gear mechanism 20 is rotated. Here, when the solenoid 32a is driven, the recording paper P in the paper feed cassette 11 is transported to the process cartridge 2 via the transport path 18 of the laser printer LP, as described above. Reference numeral 42 denotes a convex portion that can be engaged with the concave portion 37.

Here, since the lower paper feed unit 40 is constructed similarly to the upper paper feed unit, this solenoid 32
When b is driven, the recording paper P in the paper feed cassette 11 is transported to the process cartridge 2 through both transport paths 18 and 18a.

Next, the control system of the laser printer LP will be described with reference to the block diagram of FIG. 6. Since this control system is substantially the same as that of a general laser printer, it will be briefly described. The control unit 50 of the laser printer LP includes a video controller 51 and a DC controller circuit 52. The video controller 51 includes a CPU 53, a print control program and a control program for controlling transmission data reception processing described later, a plurality of types of print control language interpreters for performing print processing of print data transmitted from the external devices 100 to 102, And a ROM 55 storing outline data (outline data) defining outlines of many characters such as kanji and symbols.
A RAM 56 for receiving print data transmitted from the external devices 100 to 102 and storing the print data for a predetermined capacity;
RAM 57 for a work memory including an area for storing dot data created based on the data stored in 56
And a timing control circuit 58 for generating a timing signal when writing / reading data to / from the RAM 56, and a dual port RAM (FIFO memory) 4.
The print information which has two scan buffers of K bytes and is converted into dot data is sequentially transferred to the DC controller circuit 12.
Interface (VI / F) 59 to output to
And a panel interface (P / I / F) 60 for receiving a signal from the operation panel 62. These are connected via a bus 61 such as a data bus.

The bus 61 has external devices 100 to 10 connected thereto.
For example, in order to receive print data such as character data and image data transmitted from the communication interface 2, an interface 81 of RS232C that receives serial transmission data
Interface Units (IFUs) 63-6
5 is connected.

As shown in FIG. 2, the operation panel 62 has a liquid crystal display 62a capable of displaying one line.
Setting switches 62b for setting a plurality of setting items related to the printing process are provided.

The DC controller circuit 52 of the control unit 50 is supplied with a main motor drive circuit 67 for a main motor 66, a heater drive circuit 69 for a fixing heater 68, an electrical component circuit 70, and a high voltage. High-pressure unit 71 for operating the solenoids 32a and 3
Driving circuits 72 to 74 for 2b and 32c are connected inside the control unit 50, and the DC controller circuit 12 has a scanner for rotating a laser diode 75, which is a light emitting element of a semiconductor laser, and a hexahedral mirror at high speed. The motor 76 is connected.

Next, the interface units 63 to 6
5 will be described. These interface units 63 to 65 are similarly configured, but are given different reference numerals for convenience of explanation. Therefore, the interface unit 63 provided in the laser printer LP will be described with reference to FIG.

A connector 80 for connecting to the external device 100 via a connection cable, and an interface 81 for receiving transmission data including print data transmitted from the external device 100 via the connector 80 include a bus line B1.
And an input terminal group of a latch circuit 82 for latching transmission data output from the interface 81 and parallel data including an interrupter signal (hereinafter referred to as an INT signal) via a bus line B2. The plurality of output terminal groups of the latch circuit 82 are connected to the transmission data output terminal group of the connector 83 via the bus line B3. The INT signal output from the interface 81 is connected to the connection line C1.
Are connected to the INT terminal of the connector 83 and the input terminal of the latch circuit 82, respectively.

On the other hand, the connector 83 is provided with latch signal input terminals for inputting four latch signals L1, L2, L3 and L4. Each of the four latch signal input terminals is connected to a switch circuit 84. The input terminals of the four identification switches are connected to each other. Further, the output terminals of these discriminating switches are connected to a latch circuit 82 via a buffer signal line 85 through a latch signal line C2.
Are connected to a common gate terminal G. Further, in order to use the latch signal L1 output from the buffer gate 85 as the identification signal SS of the interface unit 63, the output terminal of the buffer gate 85 is connected to the identification signal terminal of the connector 83 via the connection line C3.

Further, the sheet detection signal output from the connector 86 to which the sheet detection sensor 43 is connected
7, the latch signal L1 is input to the other input terminal of the AND gate 88, and the output terminal of the AND gate 88 outputs the paper empty signal PE. Is connected to a paper empty terminal of the connector 83 by a connection line C4.

The connector 83 is connected to the video controller 5
1 because it is connected to the connector 89 provided in
The transmission data output terminal of the connector 83 is connected to the data bus of the bus 61 via the transmission data input terminal group of the connector 89, and the INT terminal, the identification signal terminal, and the paper empty terminal of the connector 83 are connected via the terminal of the connector 89. Each of the input ports of the CPU 53 is connected to an input port of the CPU 53, and a latch signal input terminal of the connector 83 is connected to an output port of the CPU 53 via a latch signal output terminal of the connector 89.

Further, each terminal of the connector 83 and each terminal of the connector 90 of the interface unit 63 are connected to each other by a plurality of connection lines (not shown) provided in the interface unit 63, respectively. And connector 8 of interface unit 64
3 is connected by the connection cable CB2, and the connector 90 of the interface unit 64 and the connector 83 of the interface unit 65 are connected by the connection cable CB3.
The respective signal terminals of the 64 and 65 connectors 83 are directly connected to the corresponding signal terminals of the connector 89, respectively.
The switch circuit 8 of the interface unit 63
4, one identification switch corresponding to the latch signal output terminal of the latch signal L1 is short-circuited. In the switch circuit 84 of the interface unit 64, one identification switch corresponding to the latch signal output terminal of the latch signal L2 is provided. Is short-circuited and the interface unit 6
In the fifth switch circuit 84, one identification switch corresponding to the latch signal output terminal of the latch signal L3 is short-circuited.

The operation of the interface 81 when receiving transmission data will be briefly described with reference to FIG. 10. If the interface 81 is an RS @ 232C that receives serial transmission data, this interface 81 , Serial transmission data is sequentially converted into parallel data (for example, 8 bits), and an “H” level INT signal is output when the parallel data is determined (t1). This INT signal is set to the “L” level at the time of rising (t4) of the ACK signal (acknowledge signal) output from the video controller 51, and the parallel data conversion of the serial data is performed in the same manner. The latch circuit 8
When an "H" level latch signal is supplied to the gate terminal G of the bus line 2, the parallel transmission data supplied via the bus line B2 is latched by the rise to the "H" level. Output to The transmission data output to the bus line B3 includes the INT
Signal is included.

Next, a description will be given of a transmission data reception processing control routine performed by the video controller 11 of the laser printer LP with reference to the flowchart of FIG. The recording paper P stored in each paper cassette 11 is fed by a solenoid 32 by feeding control (not shown).
-It is executed by driving 32a and 32b. Symbol Si in the figure
(I = 10, 11, 12,...) Are each step.

When the power of the laser printer LP is turned on, this control is started. First, in order to detect the presence or absence of the connected interface units 63 to 65,
At the same time as outputting the “H” level latch signal L1 from the output port of the CPU 53 for a predetermined short period of time, it is determined whether the “H” level identification signal SS has been received (S1).
0). That is, for example, in the switch circuit 84 of the interface unit 63, only the identification switch corresponding to the latch signal L1 is short-circuited, so that the "H" level latch signal L1 is output and the "H" level identification is performed at the same time. Since the signal SS is received, the interface unit 63 is connected to the latch signal output terminal of the latch signal L1, and the interface unit flag F1 is set. Similarly, the presence or absence of the interface units 63 to 65 is detected based on the signal level of the identification signal SS when the latch signals L2, L3, and L4 are sequentially output for a predetermined minute time. here,
The interface unit 63 corresponds to a latch signal output terminal of the latch signal L1, and the interface unit 6
Reference numeral 4 corresponds to a latch signal output terminal of the latch signal L2, and the interface unit 65 corresponds to a latch signal output terminal of the latch signal L3.

Next, when the transmission data is received, it waits until the INT signal output from the interface 81 is input (S11: No). When the INT signal is input (S11: Yes), it is provided in the RAM 57 in advance. In order to treat the counter value i of the counter I as a variable, "1" is stored as the expected value of the counter value i (S1).
2).

Next, when the interface unit flag Fi corresponding to the counter value i is set (S13: Yes), the "H" level latch signal Li corresponding to the counter value i is output (S1).
4). At this time, the parallel reception data supplied via the latch circuit 82 is read by the latch signal Li (S15), and "H" level IN is included in the reception data.
When the T signal is included (S16: Yes), it means that the transmission data has been supplied to the interface units 63 to 65 of the latch signal Li corresponding to the counter value i. Next, the latch signal Li ("H" level) corresponding to the counter value i is continuously output (S1).
7) A transmission data storage process for storing the transmission data in the RAM 56 is executed (S18).

For example, when transmission data is supplied to the interface unit 64, as shown in FIG. 10, an INT signal is input at a time point t1, and an "H" level latch signal L1 is first output for a predetermined short time. Is “H” level I in the supplied received data.
Since the NT signal is not detected, the "H" level latch signal L2 is output for a predetermined very short time at time t2. In the received data at this time, “H” level IN
Since the T signal is detected, the "H" level latch signal L
2 is continuously output. Then, from time t2 to time t
3, the parallel received data is read, and at time t4
The INT signal is cleared by the ACK signal, and the received data is repeatedly read in the same manner. During the reception of the transmission data, when the recording paper P in the paper feed cassette 11 runs out and a paper detection signal of “H” level is output from the paper detection sensor 43, the two input terminals of the AND gate 88 are Each of them becomes "H" level, and the AND gate 88 outputs the "H" level paper empty signal PE.
Is output.

Next, with the end of the received data, an "L" level latch signal Li is output (S19), and the process returns to S11. When the flag Fi is not set (S1
3: No) or “H” level IN in the received data
When the T signal is not included (S16: No), the counter value i is incremented by one (S20).

As described above, the interface unit 63 for receiving transmission data is connected to the laser printer LP.
On the other hand, since it is provided in each of the paper feed units 40 that can be arbitrarily added, the paper feed units 40 can be increased or decreased according to the number of external devices 100 to 102, and provided in the laser printer LP. ~ 65
May be arbitrarily increased or decreased in accordance with the number of the external devices 100 to 102 and a plurality of such devices may be provided. Further, among the plurality of identification switches of the switch circuit 84 provided in each of the interface units 63 to 65, these interface units 63 to 65 are provided with four latch signal output terminals L1 to L.
Since only one identification switch is short-circuited so as to correspond to each of the L1 and L2, the latch signal output terminals L1 to L4 from which the latch signal is output from the video controller 51 and the received "H" level INT signal are used. And specific interface units 63 to 65 that have received the transmission data.
Can be automatically selected. In addition, since recording papers P of different sizes can be stored in each paper feed unit 40, a plurality of types of recording papers P can be arbitrarily selected and used for printing.

The interface units 63-
The interface 81 provided in each of the 65 can be constituted by various interfaces such as Centronics. The switch circuit 84 can be composed of five or more identification switches. The interface units 63 to 65 can be housed in dedicated unit cases, respectively, and these unit cases can be detachably mounted on the laser printer LP.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention.

FIG. 2 is a perspective view of a laser printer and an additional paper supply unit.

FIG. 3 is an exploded perspective view of the laser printer and each paper supply unit.

FIG. 4 is a vertical sectional side view of a main part of a laser printer and a paper feeding unit.

FIG. 5 is a side view of an internal mechanism for explaining a drive system of a laser printer and a paper feeding unit.

FIG. 6 is a block diagram of a control system of the laser printer.

FIG. 7 is a circuit diagram of an interface unit provided in the laser printer and the paper feeding unit.

FIG. 8 is a circuit diagram of an interface unit provided in an additional paper supply unit.

FIG. 9 is a schematic flowchart of a transmission data reception processing control routine.

FIG. 10 is a time chart when receiving transmission data.

[Explanation of symbols]

 LP laser printer 51 video controller 80 connector 81 interface 82 latch circuit 83 connector 84 switch circuit 63, 64, 65 interface unit C2 latch signal line 100, 101, 102 external device

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-64-8435 (JP, A) JP-A-60-211589 (JP, A) JP-A-1-180037 (JP, A) JP-A-2- 120929 (JP, A) JP-A-1-221765 (JP, A) JP-A-62-16663 (JP, A) JP-A-64-50960 (JP, U) JP-A-63-171987 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) B41J 5/30 B41J 29/00 G06F 3/12

Claims (1)

(57) [Claims] 1. A printer for receiving transmission data including print data transmitted from an external device capable of transmitting data and printing the data on a print medium, comprising: a connector for connecting the external device via a connection cable; An interface for receiving transmission data via the interface, a latch circuit for receiving and latching parallel data including the transmission data and the interrupter signal from the interface, and a plurality of identifications corresponding to a plurality of latch signal output terminals of a controller of the printing apparatus. Switch, a latch signal line connecting output terminals of the identification switches to a common gate terminal of the latch circuit, and a plurality of output terminals of the latch circuit connected to a transmission data input terminal group of a controller of the printing apparatus. The input terminal of the identification switch is connected to the plurality of latch signals of the controller of the printing device. A plurality of interface units each including a connector for connecting to a power terminal; and a plurality of identification units for each of the interface units such that the plurality of interface units correspond to a plurality of latch signal output terminals, respectively. A printing device characterized in that one of the switches is short-circuited.