JPH0457514B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a printing device, and more particularly to a printing device having a function of correcting printed characters.

Prior Art In conventional printing devices, such as electronic printing devices, after printing has been completed, paper is removed from the device, and if a typo is discovered, the paper is reloaded into the device to correct it.
It was necessary to manually move the carriage, platen, etc., align the position of the character to be corrected, and perform the printing operation again via the correction ribbon to make corrections.

Not only is this operation extremely complicated, but if accurate alignment is not performed, characters often remain erased due to misalignment.

Purpose The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional type, and it simplifies the operation of correcting typos, and even after printing is completed and the paper is removed, there are still erased portions left on the paper. To provide a recording device that can reliably correct typos without causing errors.

Embodiments Hereinafter, details of the present invention will be explained based on embodiments shown in the drawings.

FIG. 1 and the following illustrate one embodiment of the present invention, using an electronic typewriter using a daisy wheel type print head as an example of a printing device.

FIG. 1 is a block circuit diagram illustrating the general configuration of this embodiment. In the figure, reference numeral 1 indicates a keyboard, which is composed of a key matrix, in which alphabet keys, numeric keys, and various other function keys are arranged. ing.

Character information input using this keyboard 1 is sent to an MPU (microprocessor) 2.
The MPU controls the amount of rotation of a daisy wheel provided in the printer 4 or the printing pressure of a printing hammer via the driver 3 to perform desired printing.

This MPU2 is a ROM (read only memory) that stores microinstruction information for sequential control as digital signals.
It consists of an arithmetic unit that processes information according to information from the ROM, a group of registers that hold numerical data, an adder that executes operations, and a control unit that performs other controls.

The MPU 2 also receives a detection signal from a sensor 5 that detects the edges of printing paper, and uses a RAM (random access memory) used for correction buffers, etc.
6 is connected.

The sensor 5 described above is installed as shown in FIG.

That is, in FIG. 2, a carriage indicated by the reference numeral 7 is slidably attached to the guide bar 8, and a daisy wheel 10 is attached to the end of the carriage on the platen 9 side. Printing is performed on the printing paper 11 that is fed along the line. What is indicated by the reference numeral 12 is a correction ribbon.

The above-mentioned sensor 5 is attached to a portion of the distal end of the carriage 7. This sensor 5 includes, for example, a light emitting element 5a and a light receiving element 5b,
The edge portion of the printing paper 11 can be detected by the difference in reflectance between the platen 9 and the printing paper 11.

Now, as shown in Figure 3 A and B, the carriage 7
The moving direction of the platen 9 is the x direction, and the rotation direction of the platen 9 is the y direction.
In order to detect the edge of the printing paper, first rotate the platen 9 to align the y direction of the printing paper.
Scan the direction and detect edge a.

Next, the carriage 7 is moved to scan in the x direction and edge b is detected. Based on the coordinates of the edges detected in this manner, the distances of characters to be printed from edges a and b are determined thereafter.

Next, the operation of this embodiment configured as above will be explained with reference to the flowchart of FIG. 4.

That is, first, when the power is turned on, its own internal registers, printer, etc. are initialized in step S1.

The process then proceeds to step S2, where the operator waits for the printing paper to be loaded, and it is determined whether or not the printing paper has been loaded. If the printing paper is loaded, the process advances to step S3 and the edge of the printing paper is detected.

The process then proceeds to step S4, where it is determined whether the loaded printing paper is for correction or for new printing. Information for this determination is given by keys pressed by the operator, etc.

If it is determined that the printing paper is paper for new printing, the process proceeds to step S5, where the key input for the first character is performed, and if the key input is made, the process proceeds to step S6. Go ahead, 1st
The distance of the th character from edges a and b of the printing paper is detected, and its position and character code are stored in a buffer.

Printing is also performed at the same time, and the process advances to step S7.
In step S7, the next key input is waited for, and if a key input is made, the process advances to step S8, where the relative position to the first character and the character code are stored in a buffer, and printing is performed.
Thereafter, steps S7 and S8 are repeated. After all printing is completed, the process returns to step S2.

On the other hand, if it is determined in step S4 that correction is specified, the process advances to step S9, and the carriage is moved to the first character position with reference to the correction buffer.

It is preferable to generate a warning sound when no document is stored in the correction buffer to notify the operator of an erroneous operation.

After the carriage has moved to the first character position, the operator can use the trace key, index key, etc. to move the carriage to the desired character position and press the correction key in the same manner as in normal correction operations.

In this way, the position of the character to be corrected can be detected accurately, and the correction work can be performed accurately on the printing paper once removed from the apparatus.

Note that in the above-described embodiment, the document that can be modified is limited to the last printed sheet of paper. In other words, corrections are limited to only the paper that has been printed, but in the case of a printing device such as an electronic typewriter that has a function to record and save documents such as a text function, the edges a and b of the paper for the first character are corrected. If the distance from the document is also stored, the registered document can be called up and edited at any time.

Further, in the above-described embodiments, a printing device using a daisy wheel type printing head has been described as an example, but it goes without saying that the present invention can be applied to other printing devices as well.

Effects As is clear from the above, according to the present invention, the recording position of the first printed character is detected and stored based on each edge of adjacent sides of a set of printing paper. Therefore, if you remove the printed paper from the recording device and reinstall it to correct a typo, the print head can be automatically moved to the first recording position, eliminating the hassle of conventional printing. This method has an excellent effect in that typos can be reliably corrected without having to perform any operations to align the characters to be corrected, and without causing misalignment.

[Brief explanation of the drawing]

The figure explains one embodiment of the present invention.
The figure is a block diagram of the control circuit, Figure 2 is a perspective view of the printing device, Figures 3A and B are a plan view and perspective view of the edge detection method, and Figure 4 is a flowchart explaining the control operation. be. 1... Keyboard, 2... Microprocessor, 5... Sensor, 7... Carriage, 9... Platen, 11... Print paper.

Claims (1)

[Scope of Claims] 1. A recording device that records on a recording medium using recording means, comprising: a sensor that detects each edge of a set of adjacent sides of the recording medium; and each edge detected by the sensor. a detection means for detecting a positional relationship between the position and a first recording position that is a recording start position; a storage means for storing the first recording position detected by the detection means; and an attached recording medium. , determination means for determining whether the recording medium is a recording medium for modifying a recorded portion or for newly recording; and when the installed recording medium is a recording medium for modifying a recorded portion; and a moving means for moving the recording means to the first recording position with reference to the storage means.