JPS5853464A - Printer - Google Patents

Abstract

PURPOSE:To prevent a printing operation from being conducted at the time of replacing a printing component part or the like, by inhibiting the reception of a command from key input means when a part of a casing for a printing means is in an opened condition, in a printer which prints in accordance with the external key input. CONSTITUTION:The casing for a main body of the printer is provided with a cover switch 22 which is so constructed as to turn OFF the printer when a casing cover is opened for replacing a ribbon cassette or a correction tape. One end of the cover swich 22 is connected to a 5V power source terminal of a printer controller 20, while the other end is connected to an AND gate 24 which sends a signal to a central processing unit 10 by taking the product with a signal from a keyboard controller 14. Accordingly, since the signal from the controller 14 can not be inputted into the central processing unit 10 in the condition where the casing cover is opened, a printer part 18 does not operate at the time of replacing component parts.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing device ζ, and more particularly to a printing device C that can control manual reading of C keys when replacing printing parts.

``Conventionally, key human power C; printing device C that performs printing operations in response to
- In order to replace printing parts such as ribbons and printing wheels (: When the cover of the housing housing the printing means is opened, the operator's hand may accidentally touch key C - When this is done, the corresponding printing is done on the printing paper C
; there was a problem that the deletion had to be performed afterward. This kind of work is an emergency; it is a wasteful operation,
In order to avoid this, the case/cover for the printing device should be opened from the
Care must be taken not to touch the keys, and the operator (
For two, the annoyance was unavoidable.

The present invention has been made in view of the above-mentioned points (;), and enables key reading control that prevents printing operation when the key is pressed manually by touching the key (-) when replacing printing parts, and improves operability. The purpose of the present invention is to provide a printing device with improved performance.

An embodiment of the present invention will be described below with reference to the attached drawings.

FIG. 1 is a block diagram of an embodiment of a printing apparatus according to the present invention, and 10 is a central processing unit (10) that monitors control of the entire system including input/output control of key input, printing operations, etc.
12 is a keyboard provided with a plurality of keys 12a.

14 is a keyboard controller connected to MPU10 through data bus 16a, address bus 16b, and system control bus 16ci, and handles the generation of key manual commands from keyboard 12 via interrupt processing line L.
UI O+- Sending Bus life 16a, 16b mentioned above
, 16c, a key manual command (2) corresponds to a required printing operation in a printing unit, which will be described later. 018 is a printer unit that performs printing, and the printing operation of this printer unit 18 is controlled by a printer controller 20 (-). This printer controller 20 also has an MPU10 and each pass line 16ae1.
6b and f6c, and print information corresponding to key manual commands is outputted through these path lines under the supervision of MPUl0. 22 is a housing C that houses the printer body. This is a cover switch with one end connected to 5 of the printer controller 20.
It is connected to a power supply terminal, and the other end is connected to an AND gate, which will be described later.

This cover switch 22 is set to turn OFF when the second housing cover is opened for replacing the ribbon cassette or the collection tape.
The input terminal of the ND gate is the interrupt processing line L of the keyboard controller 14 mentioned above and the cover switch 22.
When there is a key manual command while the cover switch is ON, that is, the cover is closed, the MPU 10+- detects this and notifies the MPU 10+-.

One embodiment of the present invention has the above-mentioned configuration, and its operation will be explained in detail below.

First, when the cover switch 22 is closed, that is, when there is no replacement of printed parts, etc. (-, assuming that the required key 12a of the keyboard 12 is pressed, this key manual command is issued by an interrupt connected to the keyboard controller 14. One input of the AND gate is set to "H" through the processing line L. At this time, the other input of the M gate is also "H", so M
PU10 recognizes that there is a key manual command, sends print information from the keyboard controller 14 to the printer controller 20 via the pass lines 16a, 16b, and 16c, and outputs the print information (correspondingly, drives the printer section 18). to perform the required printing operation.

Next, when replacing printed parts such as ribbon cassettes and collection tapes (2) When the cover is opened, the cover switch 22 turns OFF. When a key manual command is generated from the keyboard 12 by touching a key (; for example, by touching a key), the keyboard controller 14c;
”. In this case, as mentioned above (;
Since cover switch 22 is OFF, AND gate 2
The other logic of 4 is “L” and the AND condition is not established.
The MPU 10 recognizes that there was no struggle even though there was a manual key operation. Therefore, in this case C
-, no printing operation is performed, and sufficient key manual control can be performed to prevent incorrect key manual power C; such as when replacing printing parts.

As explained above, [2. Invention C] The printing device according to the present invention has a case in which a part of the casing housing the printing means is in an open state (2.
The central processing unit (- key C1 is set to prohibit acceptance of manual commands, so even if you accidentally touch the C2 key (-) when replacing printing parts, the printing operation will not be performed and the operator C2 will not be able to print.) It greatly improves operability and is extremely effective especially when applied to electronic typewriters, word processors, etc. where printing parts, etc. are often replaced.

[Brief explanation of the drawing]

The figure is a schematic block diagram of a printing device according to the present invention. 10...Central processing unit 12...Keyboard 1
4...Keyho)' Controller 18...Printer section 20...Printer controller 22...Cover switch 24...AND gate.

Claims (1)

[Claims] Control of the central processing unit (2) Keys from the external key manual means (: A printing device that drives the printing means to perform the required printing operation according to the control of the central processing unit (2) A printing device characterized in that the printing apparatus is provided with means for prohibiting the central processing unit (-) from receiving a key manual command from the key manual command when the central processing unit is in an open state.