JPH074953B2 - Printer controller - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer controller having removable memory means in a printer body, and particularly to a printer controller suitable for use as a printer as an output device of a word processor or other various computer systems. Regarding

2. Description of the Related Art In a conventional printer controller having a font memory cartridge having a built-in memory in which dot pattern character information is stored, the above memory is not accessed, of course, while the above memory is being accessed. Even when the font memory cartridge is detached from the connector of the printer body, noise may be introduced into the signal line connecting the memory in the font memory cartridge and the control unit, and the control unit may malfunction.

Aim The present invention solves the above-mentioned drawbacks of the prior art and provides a print controller which prevents malfunction of the control unit due to the operation of attaching / detaching the memory means having the memory storing the character information to / from the apparatus main body. The purpose is to provide.

In order to achieve the above object, the present invention provides a lock mechanism for locking a memory means having a memory storing character information at a predetermined position, and a memory means having a memory storing character information, In a printer controller capable of exchanging the memory means by attaching / detaching to / from the apparatus body having a control unit, a lock mechanism for locking the memory means at a predetermined position, and the memory means are completely attached / detached to / from the apparatus body. The lock release means for releasing the locked state by the lock mechanism when the lock release means is in the pressed state, and the lock release indicating the release of the locked state when the lock release means is pressed. Lock release signal generating means for continuing to output a signal, and a buffer interposed between the control unit and the memory of the memory means, During the period when the lock release signal is output from the lock release signal generating means, a predetermined signal for blocking the transmission of the signal between the control unit and the memory of the memory means is given to the buffer, It is characterized in that transmission of signals between the control unit and the memory of the memory means is blocked.

The configuration of the present invention will be described below based on examples.

FIG. 1 shows the configuration of an embodiment of a print controller according to the present invention. In FIG. 1, a font cartridge containing a memory in which character information is stored is accommodated.
10 is attached to a connector 12 fixed at a predetermined position and locked by a lock mechanism 14. The operation of the lock mechanism 14 is released by pressing the lock release button 16, and a lock release signal indicating the release state of the lock mechanism 14 is output from the switch 18 operated by the operation of the lock release button 16.
S ₁ is output.

A connector 12 is connected to a control unit 30 that performs various arithmetic processes and input / output control via a buffer (specifically, a 3-state buffer) 20 by a control bus 40, an address bus 42, and a data bus 44. The structure of the lock mechanism 14 of the font cartridge 10 is shown in FIG. In the figure, the font cartridge 10 is provided with a recess 50, and when the font cartridge 10 is mounted on the connector 12, one end of the lock member 52 is pivotally supported by a pin 58 so that the recess 50 can be inserted and removed. One end of the lever 56 and the other end of the lock member 52 are connected by a pin 54.

On the other hand, a rod 60 having a lock release button 16 at one end and the other end forming a contact mechanism of the switch 18 is provided through the case 64, and the other end of the lever 56 is attached to the rod 60 by a pin 62. It is pivotally supported. The rod 60 is constantly urged upward in the drawing by the spring 66, and the lock member 52 is pressed in the direction (left in the drawing) to be inserted into the recess 50 provided in the font cartridge 10. The lead wire 68 connected to one piece of the switch 18 is connected to the buffer 20 (see FIG. 1), and the lead wire 70 connected to the other piece of the switch 18 is a power source side or ground (not shown). Connected to the side.

In the above structure, the font cartridge 10 is connected to the connector.
When the lock release button 16 is pressed for attachment / detachment to / from the lever 12, the lever 56 rotates clockwise about the pin 58 as a fulcrum, and the lock member 52 is moved to the right in the figure, and the recess
The engagement state with 50 is released.

At the same time, the switch 18 is turned on, for example, and a lock release signal S ₁ is output to the buffer 20 by a power supply or ground lead wires 68, 70 (not shown). As a result, the buffer 20 keeps the unlock signal during the period when the unlock signal S ₁ is being output.
S _{1 is} forced to a floating state, that is, a high impedance state (open state), and transmission of a signal between the control unit 30 and the memory in the font cartridge 10 in which character information is stored is blocked.

As mentioned above, the font cartridge 10 is a locking member.
52, lever 56, rod 60 and spring 66 are always locked by a lock mechanism 14, and the lock state is released by pressing the lock release button 16 so that the font cartridge 10 can be removed. Has been done.

Further, even when the font cartridge 10 is attached to the connector 12, the lock member 52 obstructs the passage of the font cartridge 10 and the font cartridge 10 cannot be attached to the connector 12 unless the lock release button 16 is pressed. Therefore, the unlock button 16 is kept pressed until the font cartridge 10 is completely attached / detached. Therefore, during the attachment / detachment operation of the font cartridge 10, the unlock signal S ₁ is always applied to the switch 18 from the power source or ground (not shown). Will continue to be output.

As described above, in this embodiment, the lock release button 16
Since the buffer 20 is directly controlled by using the lock release signal S ₁ output from the switch 18 as a control signal when the button is pressed, the malfunction of the control unit due to the attachment / detachment operation of the font cartridge is prevented with a simple configuration. can do.

Next, FIG. 3 shows the configuration of another embodiment of the print controller according to the present invention. The present embodiment differs from the embodiment shown in FIG. 1 in the configuration. The CP which configures the control unit 30 is an unlock signal output by pressing the unlock button 16.
I / O to U80 via lead 102 as an interrupt signal S _2.
As the status signal S ₃ of the font cartridges 10 via leads 104 to the port 90, by outputting each and status signals S ₃ performs necessary processing in response to attachment and detachment of the font cartridge 10 is outputted by the CPU80 During the period, the control signal S ₄ output from the I / O port 90 to the buffer 20 via the lead wire 106 forces the buffer 20 to a floating state, that is, a high impedance state (open state). That is what I configured.

In FIG. 3, when the lock button 16 is pressed when the font cartridge 10 is attached or detached, the switch 18 outputs the interrupt signal S ₂ to the CPU 80 and the status signal S ₃ to the I / O port 90. When the CPU 80 receives the interrupt signal S ₂ , it interrupts the access when the memory in the font cartridge 10 is being accessed and receives the status signal S ₃ when it is not being accessed from the I / O port 90. Buffer 2
The control signal S ₄ is output for 0, and the buffer 20 is forcibly floated while the status signal S ₃ is being output, that is, the high impedance state (open state).
To

Also, while accessing the memory in the font cartridge 10,
If a print error occurs (for example, during print output) when access is interrupted when the CPU 80 receives the interrupt signal S ₂ , an error display is displayed on the display device 200 via the I / O port 90. A display signal is output.

As described above, in this embodiment, the CPU 80 performs the processing corresponding to whether the memory is being accessed when the font cartridge is attached or detached. In addition, it is possible to prevent malfunction of the control unit due to the attachment / detachment operation of the font cartridge.

Effect According to the present invention, a buffer is interposed between the control unit connected by a signal line and the memory of the memory unit, and the control unit and the memory are based on the signal of the unlock signal generating unit operated when the memory unit is attached or detached. Since the buffer is controlled so as to prevent signal transmission to and from the memory of the means, it is possible to prevent malfunction due to the operation for attaching and detaching the memory means.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a printer controller according to the present invention, FIG. 2 is an explanatory diagram showing a lock mechanism of a font cartridge in the printer controller according to the present invention, and FIG. 3 is related to the present invention. It is a block diagram which shows the structure of the other Example of a printer controller. Description of main part symbols 10 …… Font cartridge 14 …… Lock mechanism 16 …… Unlock button 18 …… Switch 20 …… Buffer 30 …… Control unit 80 …… CPU 90 …… I / O port

Claims (1)

[Claims] 1. A printer controller capable of exchanging the memory means by attaching and detaching the memory means having a memory storing character information to and from an apparatus main body having a controller. A lock mechanism for locking the position, a lock releasing means for releasing the locked state by the lock mechanism when the memory means is pressed until it is completely attached to and detached from the apparatus body, and a lock mechanism; A lock release signal generating means for continuing to output a lock release signal indicating release of the lock state when the release means is pressed; and a buffer interposed between the control section and the memory of the memory means. Having a memory of the control unit and the memory unit during a period in which an unlock signal is output from the unlock signal generating unit. A predetermined signal to prevent transmissions between the signals given to the buffer, the printer controller, characterized by blocking the transmission of signals between the memory of the memory means and the control unit.