JPH106566A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer for carrying out the printing operation only in the case a device main body is retained on a properly separating position from a medium to be recorded. SOLUTION: A font data is read out of a character generator 32 by a CPU 34 based on a recording data for characters input from an input section 30, and the scanning distance is computed based on the Doppler beat frequency obtained by a computation section 12, and an ink jet head 2 is driven based on the font data read out by every given scanning distance. At that time, in the case the distance from a printing face is separated more than the given interval by a signal of a proximity sensor 6, the ink jet head 2 is not driven.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing method for printing an image such as a character or a graphic on a printing surface of a recording medium by moving and scanning the apparatus body in a contact state along the printing surface of the recording medium. It concerns the device.

[0002]

2. Description of the Related Art Conventionally, there is a manual scanning type printing apparatus capable of printing on an arbitrary printing surface of a recording medium. Hereinafter, this printing apparatus will be described with reference to FIGS.

First, a mechanical configuration of the printing apparatus will be described. FIG. 5 shows the internal configuration of the printing apparatus.
The thermal head 51 is a print head having a heating resistor and a driving circuit for driving the heating resistor. Ribbon reel 52
Is rotatably supported in the device. The thermal transfer ink ribbon 53 is a recording material wound around the ribbon reel 52. The guide roller 54 is connected to the ribbon roll 52.
The thermal transfer ink ribbon 53 from the thermal head 5
It guides in one direction. Feeding rollers 55, 5
Numeral 6 applies a tension to the thermal transfer ink ribbon 53 between the guide roller 54 and the thermal transfer ink ribbon 53 guided by the guide roller 54. The encoder 57 includes a slit disk 58 and a photo interrupter 59.
The slit disk 58 is driven by the feeding roller 55 via a belt 60. Roller 61
Rotates while contacting the print surface with the feeding roller 56 during scanning of the printing apparatus.

FIG. 6 is a block diagram showing an electrical configuration of a conventional CPU and its peripherals. Input unit 62
Is a transparent touch panel for inputting recorded data of characters,
A segment display for a press monitor is provided below the panel. The character generator 63 outputs kanji font data, kana font data, English font data, and numeric font data (hereinafter simply referred to as font data). The CPU 64 reads font data from the character generator 63 based on the character recording data input by the input unit 62. On the basis of the read font data, the thermal head 51 is provided only once every predetermined scanning distance detected by the encoder 57.
Drive. The display 65 displays the characters read by the CPU 64. The console 66 instructs the format of vertical writing and horizontal writing, and sets the enlargement magnification of kanji and the like.

Next, the operation will be described. First, the console 66 selects one of a vertical writing format and a horizontal writing format. Next, when a character is input to the input unit 62, the CPU 64 causes the character generator 6 to input a character.
3 is read out, and characters are displayed on the display 65 in accordance with the selected format.

When the printing apparatus main body is placed on a sheet and scanned rightward in FIG. 5, the ribbon reel 52,
Roller 61, guide roller 54, feeding roller 55,
The rotation of the feed roller 55 causes the slit disk 58 of the encoder 57 to rotate. Therefore, the thermal head 51 is driven by the CPU 64 based on the font data at every fixed distance detected by the encoder 57.

In a general stationary type printing apparatus, it is well known that a carriage mechanism as a transport means is responsible for transporting a print head, and that the printing quality depends on the operation accuracy of the carriage mechanism. In the case of a manual scanning type printing apparatus that scans the housing manually, the accuracy of the detection means for detecting the relative movement distance between the printing surface of the printing paper and the housing determines printing quality. The detection means in a conventional manual scanning type printing apparatus is composed of a feeding roller, a belt and an encoder. For accurate detection of the relative movement distance, for example, the feeding roller uses rubber as a material so as not to idle on the printing surface, or the speed of the feeding roller is increased by a belt and transmitted to the encoder, Consideration has been given to increasing the number of slit divisions of the slit disk of the encoder.

However, there is a problem that even if the feeding roller is made of rubber, the feeding roller idles depending on the material of the printing surface, causing an error in the detection result of the relative moving distance. This is irrelevant as long as the feeding roller contacts and detects the relative movement distance. Further, there is a problem that an error occurs in the detection result of the relative movement distance due to slippage between the roller and the belt.

Further, in order to increase the detection resolution, it is necessary to increase the speed increase ratio of the belt, and there is a problem that the entire apparatus becomes large. When the speed increase ratio is insufficient, many gears are used instead of the belt, but gear accuracy and backlash occur in proportion to the number of gears, and errors occur in the detection results of the relative movement distance. There is a problem that occurs.

In order to solve such a problem, the present applicant has already proposed a printing apparatus for detecting a relative moving distance in a non-contact manner with respect to a recording medium.

In the printing apparatus proposed by the present applicant, the relative movement distance is detected by a method utilizing the so-called optical Doppler effect, and the relative movement distance with the printing medium can be easily and accurately detected. Also, there is an advantage that high printing quality can be ensured even in a manual scanning type printing apparatus. Furthermore, by using such a method, printing can be performed even when the recording medium is not in contact with the recording medium. There is also an advantage that the types of media can be expanded.

[0012]

However, in the above-described printing apparatus, the printing operation is executed even when the apparatus is not held at an appropriate position with respect to the recording medium, and printing failure occurs. There was a problem. Further, there is a problem that printing is performed on a medium other than a recording medium when careless scanning is performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and there is provided a printing apparatus which performs a printing operation only when an apparatus main body is held at an appropriate distance from a recording medium. It is intended to provide.

[0014]

In order to achieve this object, a printing apparatus according to the first aspect of the present invention performs character scanning by moving and scanning along a printing surface of a recording medium in a non-contact state. Recording means for printing images such as images and figures;
A moving amount detecting means for detecting a relative moving amount of the recording means with respect to the recording medium in a non-contact state with a printing surface of the recording medium, and a relative moving amount detected by the moving amount detecting means; And a control means for controlling the driving of the recording means, in particular, a separation state detection for detecting a separation state of the recording means from a printing surface of a recording medium in a non-contact state with the printing surface. Means, wherein the control means is configured to stop driving the recording means when the separation state detection means detects a separation state of a predetermined distance or more.

Therefore, according to this printing apparatus, by moving the recording means in a non-contact state along the printing surface of the recording medium in a non-contact state, the movement amount detecting means is capable of moving the recording means with respect to the recording medium. Is detected in a non-contact state with the printing surface of the recording medium, and based on the detected relative movement, the control means controls the driving of the recording means, and The means prints an image such as a character or a figure on a recording medium. During the printing, the separation state detecting means detects the separation state of the recording means from the printing surface of the recording medium in a non-contact state with the printing surface. During this detection, if the separation state detecting means detects a separation state of a predetermined distance or more, the driving of the recording means is stopped. That is, if the recording means is too far from the printing surface of the recording medium, the printing operation of the recording means is immediately stopped. Therefore, correct printing results can be obtained by printing again. Therefore, the printing operation is not performed in a state where the recording unit is not held at an appropriate spaced position with respect to the recording medium, so that erroneous printing can be prevented, and blurred printing disturbance can be prevented.

Further, in the printing apparatus according to the present invention, the separation state detecting means is provided near the recording means. Therefore, the distance between the recording unit and the printing surface of the recording medium can always be accurately detected, and the control of the driving and stop of the recording unit by the control unit can be accurately performed.

Further, the printing apparatus according to a third aspect of the present invention includes a notifying means for notifying a user when the separated state detecting means detects a separated state of the predetermined distance or more.
Therefore, when the user is notified by the notification means,
It can be seen that the recording means is too far from the printing surface of the recording medium, and thereafter, the user can perform printing accurately by keeping the recording means within the predetermined distance.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a printing apparatus according to an embodiment of the present invention.

First, the hardware configuration of the printing apparatus will be described. FIG. 1 schematically shows the internal configuration of the printing apparatus according to the present embodiment. An ink jet head 2 as a printing unit is provided in the apparatus housing 1, and the ink jet head 2 is a recording element having a drive circuit, and directly ejects ink onto a printing surface 15 of a printing paper as a recording medium. . The ink cartridge 4 supplies ink to the inkjet head 2. Light emitting units 8a, 8b
Has a built-in microlens for outputting a laser beam toward the printing surface 15 and condensing the laser beam in an output section of the laser beam. The light receiving unit 10 is a pin photodiode, and is configured to receive the laser beam reflected by the printing surface 15 and convert the laser beam into an electric signal. In addition, a proximity sensor 6 to be described later is arranged near the inkjet head 2. The proximity sensor 6 outputs an electric signal according to the distance between the inkjet head 2 and the printing surface 15. In the present embodiment, a capacitance type sensor is used for the proximity sensor 6. The proximity sensor 6 constitutes a separation state detecting means of the present invention.

Next, a method for optically measuring the relative moving distance between the printing apparatus and the printing surface 15 will be described with reference to FIGS.

First, a laser beam whose beam has been narrowed is applied from a pair of opposing light projecting portions 8a and 8b to a perpendicular line on the printing surface 15 at an angle of θ. The laser light is scattered by irregularities on the printing surface 15 and fine particles (particle diameter φ is approximately equal to or less than the wavelength of the laser light) adhered on the printing surface 15 (hereinafter, factors relating to these scattering are referred to as scattering factors). ). This scattered light is detected by the light receiving unit 10 arranged on a perpendicular line. This measuring method is called a laser Doppler method, and the present optical system is particularly of a two-beam incident type operation type. With this optical system, a light intensity signal due to a scattering factor, called a Doppler beat signal, is obtained. The Doppler beat signal is obtained by removing the pedestal component, which is a low frequency component, by the filter 20, clipping the pedestal component by the waveform shaping circuit 21, and measuring the frequency by the frequency counter 22.
Frequency change Δ of Doppler effect due to scattering on printing surface 15
f. Here, the Doppler beat frequency Δf and the scattering factor velocity v on the printing surface 15 have the following formula.

[0022]

(Equation 1)

That is, by measuring the Doppler beat frequency Δf, the speed of the scattering factor, that is, the relative moving speed between the printing device and the printing surface can be obtained. This measurement method is described, for example, in a Sanshin article, “Application of Optical Heterodyne Detection Method to Measurement” (Applied Physics, 6 (1973) 560).
And "Optical Measurement Technology" (edited by the Japan Society of Mechanical Engineers, Asakura Shoten)
In detail. The Doppler beat frequency Δ
f is input to a CPU, which will be described later, to obtain the relative moving speed, and further integrate over time to calculate the relative moving distance.

Next, based on the block diagram shown in FIG. 4, an electrical control configuration including the printing apparatus and peripheral devices will be described.

The input unit 30 has a transparent touch panel for inputting character record data, and a segment display for a press monitor disposed below the panel. Character generator 32 outputs font data. CPU
34 reads out font data from the character generator 32 based on the recording data of the characters input by the input unit 30, calculates the scanning distance from the Doppler beat frequency Δf obtained by the calculation unit 12 described later, The inkjet head 2 is driven for each distance based on the read font data. At this time, if the distance from the printing surface 15 is longer than a predetermined interval by the output signal of the proximity sensor 6, the inkjet head 2 is not driven. The display 36 displays the characters read by the CPU 34 and, when the distance from the printing surface 15 is longer than a predetermined interval, notifies the user by the output signal of the proximity sensor 6. I do. The console 38 indicates the format of vertical writing and horizontal writing.

The arithmetic unit 12 and the CPU 34 shown in FIG. 2 constitute the control means of the present invention. Further, the display 36 constitutes a notification means of the present invention.

Next, the printing operation will be described. First,
The console 38 selects one of a vertical writing format and a horizontal writing format. Next, characters are input to the input unit 30. Then, the font data is read from the character generator 32 by the CPU 34, and the characters are displayed on the display 36 according to the selected format.

Then, the user lifts the printing device housing 1 upward from the printing surface 15 of the printing paper, and holds the printing device housing 1 so that the nozzles of the ink jet head 2 are arranged at an appropriate upward distance from the printing surface 15. Scanning movement is performed so as to be parallel to the printing surface 15. At this time, the pair of light emitting portions 8a and 8b
Project laser light onto the printing surface 15 and scatter light
0 is detected and output. The output signal is supplied to the Fourier transform unit 19, the filter 20, and the waveform forming circuit 2 in the arithmetic unit 12.
The signal is processed by the frequency counter 22 via 1 to obtain a Doppler beat frequency Δf.

On the other hand, the proximity sensor 6 outputs a voltage corresponding to the distance between the ink jet head 2 and the printing surface 15 of the printing paper. The CPU 34 compares the output voltage from the proximity sensor 6 with a reference voltage. When the output voltage from the proximity sensor 6 is lower than the reference voltage, the printing operation is immediately stopped because the distance between the inkjet head 2 and the printing surface 15 is too large, and a warning is displayed on the display 36 at the same time. To inform the user. On the other hand, when the output voltage from the proximity sensor 6 is higher than the reference voltage,
Assuming that the distance between the inkjet head 2 and the printing paper is within an appropriate range, the scanning distance is calculated from the Doppler beat frequency Δf, and the inkjet head 2 is driven at regular intervals based on the font data. As a result, characters are printed.

As described above, when the proximity sensor 6 detects that the distance between the ink jet head 2 and the printing surface 15 is too large, the printing is temporarily interrupted and the printing is restarted from the beginning. If the line is in the middle, print again from the beginning of the line to obtain a correct print result.

According to the above-described printing apparatus, printing can be performed in a non-contact state with respect to the printing medium, and printing defects due to an excessively long distance from the printing medium can be prevented. Good printing results are obtained.

Further, when the distance between the ink jet head 2 and the printing surface 15 of the printing paper is longer than a predetermined distance, the display 36 warns the user of this fact, so that the user can print accurately. Can be.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

In the above embodiment, an example in which a capacitance type sensor is used as the separation state detecting means has been described. However, similar effects can be obtained by using a non-contact type distance measuring sensor such as an ultrasonic sensor or an optical sensor. Is obtained.

In the above-described embodiment, the linear relative movement distance with respect to the printing medium is detected. However, for example, a new light projecting unit is set so as to be orthogonal to the above-described light projecting unit. If it is provided so as to be able to detect the movement of the two axes, a printing device of a type capable of freely scanning and printing on the printing medium even in a curved line is possible. The movement of the two axes is measured by, for example, a time division method. That is, by dividing the measurement time into two and repeating the measurement in both directions alternately, the movement of the two axes can be measured by one light receiving unit.

Further, for example, the printing device may be configured so as to be connected to an external text editing device such as a personal computer in the same manner as an ordinary printer, without including an input unit or the like. In this case, an interface for inputting character data from a personal computer, a print position display, an ink jet head, a CPU, and peripheral devices are provided.

Further, in the above embodiment, when the distance between the ink jet head 2 and the printing surface 15 of the printing paper is longer than a predetermined distance, the display 36 informs the user of the fact by a display. Alternatively, a buzzer may be sounded, or a lamp may be turned on or blinked.

[0038]

As is apparent from the above description, according to the printing apparatus of the first aspect of the present invention, by moving and scanning in a non-contact state along the printing surface of the recording medium, the character can be read. Recording means for printing images such as images and figures;
A moving amount detecting means for detecting a relative moving amount of the recording means with respect to the recording medium in a non-contact state with a printing surface of the recording medium, and a relative moving amount detected by the moving amount detecting means; And a control means for controlling the driving of the recording means, in particular, a separation state detection for detecting a separation state of the recording means from a printing surface of a recording medium in a non-contact state with the printing surface. Means, wherein the control means stops driving of the recording means when the separation state detecting means detects a separation state of a predetermined distance or more.

Accordingly, the drive of the recording means can be stopped immediately when the separation state detecting means detects a separation state of a predetermined distance or more. Therefore, correct printing results can be obtained by printing again. Therefore, in a state where the recording unit is not held at an appropriate separated position with respect to the recording medium, the printing operation is not performed, so that erroneous printing can be prevented, and printing fading and printing disorder can be prevented.

According to the printing apparatus of the present invention, since the separation state detecting means is provided near the recording means, the separation distance of the recording means from the printing surface of the recording medium can be reduced. Can always be accurately detected,
The drive and stop control of the recording unit by the control unit can always be performed accurately.

Further, according to the printing apparatus of the third aspect, when the separation state detecting means detects the separation state of the predetermined distance or more, the notification means for notifying the user is provided. When the user is notified, it is understood that the recording unit is too far from the printing surface of the recording medium. Therefore, thereafter, the user can accurately perform printing by setting the recording means within the predetermined distance.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of an internal configuration of a printing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a calculation unit of the printing apparatus.

FIG. 3 is an explanatory diagram of optical measurement in a printing apparatus.

FIG. 4 is a block diagram illustrating an electrical configuration of a CPU of the printing apparatus and a peripheral portion thereof.

FIG. 5 is a schematic configuration diagram showing an internal configuration of a conventional manual scanning type printing apparatus.

FIG. 6 is a block diagram showing an electrical configuration of a CPU and its peripherals in a conventional printing apparatus.

[Explanation of symbols]

 2 Inkjet head 6 Proximity sensor 8a Light emitting unit 8b Light emitting unit 10 Light receiving unit 12 Arithmetic unit 15 Printing surface 34 CPU 36 Display

Claims (3)

[Claims] 1. A recording unit for printing an image such as a character or a figure by moving and scanning along a printing surface of a recording medium in a non-contact state, and a recording unit relative to the recording medium. Moving amount detecting means for detecting a large moving amount in a non-contact state with the printing surface of the recording medium, and controlling the driving of the recording means based on the relative moving amount detected by the moving amount detecting means. And a separation state detection means for detecting a separation state of the recording means from a printing surface of a recording medium in a non-contact state with the printing surface, wherein the control means includes the separation state detection means. A printing apparatus configured to stop driving of the recording unit when detecting a separation state of a predetermined distance or more. 2. A printing apparatus according to claim 1, wherein said separation state detecting means is provided near said recording means. 3. The printing apparatus according to claim 1, further comprising a notification unit that notifies a user when the separation state detection unit detects the separation state of the predetermined distance or more.