JPH06135092A - Printer - Google Patents

Abstract

PURPOSE:To attach and detach a cartridge without generating erroneous operation even when the power supply of a printing main body is not cut off. CONSTITUTION:When a cartridge 2 is mounted on a printing main body 1, at first, ground terminals 32, 42 are mutually connected and, next, data bus terminals 34, 44, a read/write terminal 35 and address bus terminals 36, 45 are mutually connected. Power supply terminals 31, 41 are mutually connected and, finally, a ground terminal 33 and a detection terminal 43 are connected to bring a transceiver 21 and a bus buffer 23 to an input/output possible state from an input/output impossible state (high impedance state).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention adds a font by installing a cartridge in a printing main body and RA
The present invention relates to a printing device that increases the M memory area or changes the emulation of data processing.

[0002]

2. Description of the Related Art Conventionally, in these printing apparatuses, the power source of the printing main body is shut off before the cartridge is attached / detached so that the electronic elements in the cartridge and the printing main body are not damaged.

[0003]

However, the conventional printing apparatus has a problem in that the power of the printing main body must be cut off each time the cartridge is attached or detached, which is troublesome for the user.

Further, there are cases where the user attaches or detaches the cartridge without shutting off the power source of the printing main body, in which case there is a problem that the printing apparatus may malfunction.

The present invention has been made in order to solve the above-mentioned problems, and does not malfunction even if the cartridge is detached and attached while the power source of the printing main body is turned on. Another object of the present invention is to provide a printing apparatus that does not damage the electronic elements of the above.

[0006]

In order to achieve this object, a printing apparatus according to claim 1 of the present invention is provided with a printing body and a cartridge, respectively, a power supply terminal connectable to each other, a printing body and a cartridge. Provided in each of the
A ground terminal that can be connected to each other, a data input / output terminal that is provided on each of the printing body and the cartridge and that can be connected to each other, and an input / output unit that is provided on the printing body and that is connected to the data input / output terminal of the printing body. , And a switching means for switching the input / output unit between an input / output enabled state and an input / output disabled state.

Further, the printing apparatus according to the second aspect of the present invention is provided with a switching means for setting the input / output unit to the high impedance state to make the input / output impossible state.

[0008]

In the printing apparatus according to claim 1 of the present invention having the above structure, when the cartridge is mounted on the printing main body, the power supply terminal and the data input / output terminal are connected after the ground terminal is connected. Then, the switching means switches the input / output unit from the input / output enabled state to the input / output disabled state.

Further, in the printing apparatus according to the first aspect of the present invention, the switching means puts the input / output unit in the high impedance state to make the input / output impossible.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A printer according to an embodiment of the present invention will be described below.

FIG. 1 shows the outer appearance of the printing main body 1 and the cartridge 2. The printing main body 1 is provided with a cartridge slot 3 into which the cartridge 2 can be mounted, and the cartridge 2 can be detached by the user.

The cartridge 2 mounted on the printing main body 1 is, for example, a font cartridge for adding a font other than the fonts built in the printing main body, a RAM cartridge for increasing the RAM capacity used for the input buffer built in the printing main body, or the like. There is an emulation cartridge that changes the emulation that performs data processing built into the printing body.

FIG. 2 is a circuit configuration diagram showing an electrical configuration of the contact portions 11 and 12 which are electrical connection portions between the printing main body 1 and the cartridge 2.

In the contact portion 11 on the cartridge 2 side, pin 1 is a power supply terminal 31 to which + 5V power is supplied from the printing body 1 side. Pins 2 and 3 are ground terminals 32 and 33. Pins 4 to 11 are data bus terminals 34 for transferring data between the printing body 1 and the cartridge 2. Pin 12 is a read / write terminal 35 that determines the data transfer direction. Pins 13 to 17 are address bus terminals 3 that indicate addresses of transfer data inside the cartridge 2.
It is 6.

In the contact portion 12 on the printing body 1 side, pin 1 is a power supply terminal 41 for connecting to the power supply terminal 31 on the cartridge 2 side and supplying + 5V power when the cartridge is mounted. Further, the pin 2 is connected to the ground terminal 32 on the cartridge 2 side when the cartridge is mounted, and the ground terminal 42 for making the ground common.
Is. The pin 3 is connected to a circuit 20 including a + 5V power source, a resistor R, a capacitor C, and a ground and an input portion of a buffer driver 21 described later, and a ground terminal 33 on the cartridge side when the cartridge 2 is mounted.
Is a detection terminal 43 for detecting the mounting of the cartridge 2 by being connected to.

Pins 4 to 11 are data bus terminals 44 respectively connected to the B line 27 of the transceiver (74LS640) 22 for switching the connection with the data bus 54 inside the printing main body 1, and the cartridge 2
Is connected to the data bus terminal 34 on the cartridge side.

Pins 12 to 17 are the Y line 28 of the bus buffer (74LS125) 23 for switching the connection with the address bus 55 inside the printing body 1.
Address bus terminals 45 that are respectively connected to the address bus terminals 3 on the cartridge side when the cartridge 2 is mounted.
6 is connected.

The output section of the buffer driver 21 is connected to the enable 24 of the transceiver (74LS640) 22, the enable 26 of the bus buffer (74LS125) 23, and the I / O pin 52 of the CPU 51.

When the cartridge 2 is mounted on the printing body 1, the pins of the cartridge 2 and the printing body 1 are joined with the same pin number. As shown in FIG. 2, the length is increased in the order of 2 pins, 4 pins to 17 pins, 1 pin, 3 pins.

Further, the data bus 54 inside the printing main body 1
Are each connected to the A line 29 of the transceiver (74LS640) 22.

The address bus 55 and the read / write signal 53 are transferred to the bus buffer (74LS125) 23.
Internal CP of the printing main body 1 connected to the A line 30 of
It is accessed at U51. Read / write signal 5
3 is also connected to the direction 25 of the transceiver (74LS640) 22.

Next, the specific operation of the present invention will be described with reference to FIGS.

FIG. 3 shows the first stage in a state in which the cartridge 2 is not attached to the printing main body 1, but the following description will be given with the power being supplied to the printing main body 1 side.

FIG. 4 shows the second stage in the process of mounting the cartridge 2 on the printing main body 1. As described in the above configuration, only the ground terminal 42 (2 pins) on the printing main body 1 side is the cartridge 2. It is connected to the ground terminal 32 (pin 2) on the side, and the grounds of both sides are common. The shaded portions of each terminal indicate that the terminals are connected to each other.

FIG. 5 shows the third stage in the process of further mounting, and the ground terminals 32 and 42 (2 pins) are shown in FIG.
Data bus terminal, read / write terminal, address bus terminal 34, 35, 36, 44, 45
(4th to 17th pins) are connected to each other.

FIG. 6 shows the fourth stage in the process of further mounting, and the ground terminals 32 and 42 (2 pins) are provided.
And data bus terminals, read / write terminals, address bus terminals 34, 35, 36, 44, 45 (4 pins to 1
In addition to the connection of 7 pins), power terminals 31 and 41 (1 pin) for supplying power from the printing main body 1 are connected. Power is supplied to the cartridge 2 side by this, and the cartridge 2
The internal electronic device becomes operable.

FIG. 7 shows the final fifth stage in which the cartridge 2 is mounted until it stops, and the ground terminal 33 (3 pin), which is the ground on the cartridge 2 side, is the detection terminal (3) on the printing main body 1 side. Pin). As a result, the input section of the buffer driver 21 becomes Low from High (+ 5V) in the first to fourth stages.
(GND), and the output of the buffer driver 21 also changes from High to Low in accordance with this change.

From this, the transceiver (74LS64
0) 22 enable 24 becomes Low, and the first to fourth
Transceiver (74LS640) 22B which was in input / output impossible state on stage due to high impedance
The line 27 is ready for input / output with the data bus terminal 34 on the cartridge 2 side.

The data bus 54 connects the read / write signal 53 from the CPU 51 to the direction 25 of the transceiver (74LS640) 22 so that both directions are possible. In the case of writing, the signal of the data bus 54 can be transferred from the printing main body 1 to the cartridge 2.

Similarly, a bus buffer (74LS125)
Since the enable 26 of 23 also becomes Low, the first to fourth
At the stage, the Y line 28 of the bus buffer (74LS125) 23, which cannot be output because of high impedance, is ready to be output to the address bus 36 on the cartridge 2 side.

Since the CPU 51 inside the printing main body 1 reads the output of the buffer driver 21 through the I / O pin 52, it is possible to control the input / output by judging that the cartridge 2 is mounted. As a result, after the cartridge 2 is completely installed, the contents of the cartridge 2 can be read and written.

When the cartridge 2 is removed from the printing main body 1, the detection terminal 43 (3 pin) comes off from the ground terminal 33 (3 pin) at the time of shifting from the 5th stage described above to the 4th stage. (74LS640) Enable 24 of 22 changed from Low to High, transceiver (74LS640)
B line 27 of 22 and bus buffer (74LS12
5) The Y line 28 of 23 changes to a high impedance state and becomes an input / output impossible state.

Further, by moving to the third stage, the power supply terminals 31 and 41 to the cartridge 2 are disconnected and the power supply is cut off, and the data bus terminals, read / write terminals and address bus terminals 34 and 35 at the second stage. , 36,
44, 45 (4th to 17th pins) come off, and finally the ground comes off and the cartridge 2 and the printing body 1 are separated.

As described above, in this embodiment, when the cartridge 2 is mounted on the printing main body 1, the detection terminal 43 (3
Pin (electrical) connection only, transceiver (74LS
640) 22 B line 27 and bus buffer (74
Since the Y line 28 of the LS 125) 23 is set to a high impedance state to make it impossible to input / output, the configuration is simple, the reliability is high, and the cost can be reduced.

The present invention is not limited to the embodiments described in detail above, and various modifications may be made without departing from the scope of the invention. For example, although the present embodiment has been described with reference to a cartridge having a data bus and an address bus such as a font cartridge, it is also possible to use a cartridge such as a replaceable print head. Further, in the present embodiment, the transceiver 22 and the bus buffer 23 are set to the input / output ready state by connecting the detection terminal 43 (3 pin) to the ground terminal 33 (3 pin) of the cartridge 2. The transceiver 22 and the bus buffer 23 may be configured to be capable of inputting / outputting by a micro switch or the like that operates by mounting.

[0036]

As is clear from the above description, in the printing apparatus of the present invention, even if the power of the printing main body is not shut off, no malfunction occurs, and the electronic components in the cartridge and the printing main body The cartridge can be attached / detached without damaging the element, thereby improving the reliability of the entire apparatus.

[Brief description of drawings]

FIG. 1 is an external configuration diagram of a printing body and a cartridge according to an embodiment of the present invention.

FIG. 2 is an electrical circuit configuration diagram of the printing main body and the cartridge.

FIG. 3 is an explanatory diagram for explaining an electrically connected state of the printing main body and the first stage of the cartridge.

FIG. 4 is an explanatory diagram for explaining an electrical connection state of the printing main body and the second stage of the cartridge.

FIG. 5 is an explanatory diagram for explaining an electrical connection state of the third stage of the printing main body and the cartridge.

FIG. 6 is an explanatory diagram for explaining an electrically connected state of the printing main body and the fourth stage of the cartridge.

FIG. 7 is an explanatory diagram for explaining an electrically connected state of the fifth stage of the printing main body and the cartridge.

[Explanation of symbols]

 1 Printing Main Body 2 Cartridge 20 Circuit 21 Buffer Driver 22 Transceiver (74LS640) 23 Bus Buffer (74LS125) 31 Power Supply Terminal 32 Ground Terminal 33 Ground Terminal 34 Data Bus Terminal 35 Read / Write Terminal 36 Address Bus Terminal 41 Power Supply Terminal 42 Ground Terminal 43 Detection terminal 44 Data bus terminal 45 Address bus terminal

Claims (2)

[Claims] 1. A printing apparatus comprising a cartridge which can be attached to and detached from a printing body, wherein the printing body and the cartridge are provided with power terminals that can be connected to each other, and the printing body and the cartridge are provided with each other, and A connectable ground terminal, a data input / output terminal provided on each of the printing body and the cartridge and connectable to each other, and an input / output unit provided on the printing body and connected to the data input / output terminal of the printing body And a switching means for switching the input / output unit between an input / output enabled state and an input / output disabled state, and when the cartridge is attached to the printing main body, the power supply terminal is connected after the ground terminal is connected. And the data input / output terminal is connected, and then the switching means switches the input / output section from the input / output enabled state to the input / output disabled state. As described above, the printing apparatus is characterized in that the power supply terminal, the ground terminal, the data input / output terminal, and the switching means are arranged on the cartridge and the printing main body, respectively. 2. The printing apparatus according to claim 1, wherein the switching unit puts the input / output unit in a high impedance state so that the input / output cannot be performed.