JPS6297857A - Recording apparatus - Google Patents

Abstract

PURPOSE:To record a dot matrix having finer resolution than the resolution of a dot matrix of a recording head, by providing a means to make the recording head scan and be transferred at a finer pitch than the resolution of said dot matrix in relation to a recording medium, a common driving means and a controlling means to make these means operate in a plurality of times for recording of one line, in a dot matrix recording apparatus. CONSTITUTION:When a motor 28 is rotated normally and reversely, a carriage 30 is reciprocated to the right and the left along a lead screw 29. When a retchet roller 39 and a ratchet gear 36 of the lead screw 29 come in contact with each other and pawl members 41 and 42 engage with each other, CPU 52 transmitting the one-directional rotation of the ratchet roller 39 controls the operations of a recording head 31 and the motor 28 through a recording control element 50 by means of a control signal PS, so as to move the carriage 30 for first printing along the lead screw 29 at dot intervals being closer twice than that of an ordinary character. Furthermore, the lead screw 29 is rotated by 1/24 to conduct second recording in the same way, and then the carriage is returned. Thus, a dot matrix of high density is recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording device, and particularly to a recording device that records on a recording medium using a dot matrix.

[Prior Art] Various recording methods have been known for dot matrix printers, such as a wire dot method, an inkjet method, and a thermal transfer method, but recently, small and inexpensive recording devices that can record high-quality characters and graphics have been developed. Demand is increasing.

In particular, Japanese word processors require a dot matrix of at least 16 dots in the vertical and horizontal directions, and it has been difficult to record high-quality Chinese characters with a recording head with fewer dots.

[Problems to be Solved by the Invention] Therefore, conventionally, many recording devices for Japanese word processors and the like are equipped with a recording head of 24 x 24 dots or more, and as a result, the recording head becomes large and its control becomes complicated. This class of recording devices has had the problem of being difficult to miniaturize or reduce in price.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a recording head that records on a recording medium using a dot matrix, and a recording head that records at a pitch finer than the resolution of the dot matrix. means for scanning a recording medium at a speed of 100 degrees, means for transporting the recording medium at a pitch finer than the resolution of the dot matrix, and a common driving means for independently applying driving force to the scanning and transporting means. 5. A configuration is adopted in which a control means is provided for operating the scanning means and the transport means a plurality of times to perform recording when one recording line is formed.

[Operation] According to the above configuration, since the recording operation is performed while changing the positional relationship between the recording head and the recording medium at a pitch finer than the resolution of the recording head, the recording operation is performed while changing the positional relationship between the recording head and the recording medium at a pitch finer than the resolution of the recording head. It becomes possible to record dot matrices with high resolution, and for example, it becomes possible to record characters or images composed of dot matrices of 16 x 16 dots or more using an 8 x 8 dot recording head.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

Figure 1 and the following diagrams explain one embodiment of the present invention.
The figure shows the overall structure.

In FIG. 1, the reference numeral 20 is a platen holder, and a platen 21 is attached to the front side of the platen holder.

This platen holder 20 has its lower end connected to a rubber roller shaft 22.
It is rotatably supported on a shaft. The platen holder 20 is pressed by a spring 23 provided between the side opposite to the side where the platen 21 is provided and a fixed part of the printing device (not shown), and is pushed toward the carriage 30 side, which will be described later. It is given a rotational habit. Furthermore, rubber rollers 24 are fixed to the rubber roller shaft 22 on both sides of the lower end of the platen holder 20. Further, a pinch roller 25 is in contact with the lower, shiny front side of the rubber roller 24, and a recording paper 26 is held between the pinch rollers 24 and 25.

Further, on one side of the platen holder 20, for example, on the left end in FIG. 1 which is the home position side of the carriage 30, an engaging portion 27 is provided protrudingly provided with a cam surface 27a bulging toward the front side. ing.

Further, at a position facing the platen 21, a lead screw 29, which is a cam member rotated by a motor 28, is arranged parallel to the platen 21. A carriage 30 having a female thread 30a formed on the inner diameter is fitted into the lead screw 29. Therefore, when the motor 28 is rotated in the forward or reverse direction, the lead screw 29 also follows, and the carriage 30 can reciprocate from side to side along the lead screw 29.

Further, the carriage 30 is provided with a thermal head, for example, a 1×8 dot thermal head 31 facing the platen 21, and this thermal head 31 can perform recording on the recording paper 26 in a dot matrix. And this thermal head 31 has a spring 23.
The platen 21 is pressed by. In addition, 31a
is a heating element, which is provided in the thermal head 31 and generates heat in response to an image information signal from a control system, which will be described later.

Furthermore, a protrusion 32 of a predetermined length is provided on the side surface of the engaging portion 27 of the carriage 30. This protrusion 32 is in a position where it can engage with the engaging portion 27 when the carriage 30 returns to the home position. The carriage 30 is guided by a guide rail 33 so as not to rotate as the lead screw 29 rotates. The carriage 30 also has a set arm 34 that is slidable in the axial direction of the lead screw 29.
is provided, and a spring 35 gives it a tendency to move toward the home position.

Further, a ratchet gear 36 is attached to the left end of the lead screw 29, and this ratchet gear 36 meshes with a paper feed gear 38 via a clutch gear 37 including a one-way clutch. Note that this paper feed gear 38
is fixed to one end of the rubber roller shaft 22.

Here, the clutch gear 37 is configured to rotate only in the paper feeding direction of the recording paper 26. Further, a ratchet roller 39 is fitted onto the lead screw 29 between the ratchet gear 36 and the carriage 30, and similarly to the carriage 30, the ratchet roller 39 has a female thread 39a formed on the inner diameter to fit into the lead screw 29.

The ratchet roller 39 and the ratchet gear 36 are urged in a direction to be separated from each other by a spring 40, and claw portions 41 and 42 that engage only in the paper feeding direction are provided on surfaces facing each other. .

When the ratchet roller 39 and the ratchet gear 36 come into contact and the claws 41 and 42 engage, rotation of the ratchet roller 39 in one direction (paper feeding direction) is transmitted to the ratchet gear 36. .

Further, the set surface 43 of the set arm 34 on the opposite side of the carriage 30 pushes the ratchet roller 39 to the left when the carriage 30 comes near the home position so that the ratchet gear 36 and the ratchet roller 39 come into contact with each other. fulfill the role of

Next, the operation of the printing apparatus of this embodiment configured as above will be explained.

During the printing operation, as shown in FIGS. 2(a) and 2(b), the protrusion 32 protruding from the carriage 30 touches the platen holder 2.
It is separated from the engaging portion 27 provided at the left end of 0. Then, the platen holder 20 is pushed by the spring 23,
The platen 21 is connected to the thermal head 31 via the recording paper 26.
is being imposed.

When the motor 28 is rotated in the forward direction in this state, the lead screw 29 rotates so that the carriage 30 moves to the right in FIG. The heating element 31a generates heat according to the information signal, and printing is performed on the recording paper 26.

When printing is completed up to the predetermined end position of one line in this manner, the motor 28 rotates in the reverse direction, and the thermal head 31 returns to the home position together with the carriage 30.

At this time, since the ratchet roller 39 and the ratchet gear 36 are separated from each other by the spring 40, the rotation of the lead screw 29 is not transmitted to the ratchet gear 36, and paper feeding is not performed.

When the carriage 30 approaches the home position, the protrusion 32 first comes into contact with the cam surface 27a of the engaging portion 27 and rides on it, as shown in FIGS. 3(a) and 3(b). Since the carriage 30 can only move in the axial direction of the lead screw 29, the engaging portion 27 is pushed by the protrusion 32, and the platen holder 20 is rotated in a direction away from the thermal head 31 against the elastic force of the spring 23. .

On the other hand, when the carriage 30 approaches the home position,
As shown in FIG. 3(a), the set surface 43 of the set arm 34 pushes the ratchet roller 39 to the left, so the ratchet roller 39 and the ratchet gear 36 come into contact with each other, and the claws 41 and 42 are brought into engagement. Become. The position of the carriage 30 at this time is the home position.

When the lead screw 29 is further rotated, the carriage 30 moves further leftward from the home position to outside the printing range, as shown in FIG.

At this time, the set arm 34 maintains the position where the ratchet roller 39 and the ratchet gear 36 are in contact, so the rotation of the lead screw 29 is transmitted to the ratchet gear 36.
Paper is fed. Therefore, by appropriately selecting the gear ratios of the ratchet gear 36, clutch gear 37, and paper feed gear 38, it is possible to accurately feed the paper by one line with one rotation of the lead screw 29, for example.

Therefore, by controlling the amount of rotation of the lead screw 29, that is, the amount of movement of the thermal head 31 further to the left from the home position, the amount of feeding of the recording paper 26 can be controlled.

In addition, since the platen 21 and the printing pad 31 are separated from each other during paper feeding, the printing pad 31 does not interfere with paper feeding.

After the paper is fed in this manner, the lead screw 29 is rotated in the forward direction to move the carriage 30 to the right and return it to the home position.

At this time, the ratchet gear 36 tries to rotate in the reverse direction, but since the clutch gear 37 is in the direction in which it does not rotate, the force that causes the ratchet roller 39 to separate from the ratchet gear 36 is strong, and the recording paper 26 does not rotate back.

The operating principle of the printing apparatus according to this embodiment is as described above, and the actual operation for printing normal characters and high-quality characters will now be described.

It is now assumed that eight heating elements 31a are provided in a vertical line in the print head 31.

Then, the line spacing in the case of normal character printing is set to L as shown in FIG.
The dot spacing is set to L/12 as shown in FIG. 5(b).

Furthermore, the ratchet gear 36 and the ratchet roller 39 are each provided with three claws 41 and 42 at equal intervals.

When performing normal character printing based on such a configuration, the carriage 30 is connected to the lead screw 2 at a dot interval α.
In this embodiment, one character is made up of 8 vertical dots x 5 horizontal dots. −
After the character printing is completed, the motor 28 is reversely rotated and the lead screw 29 is rotated once in the paper feed direction from the home position, thereby allowing the paper to be fed by the character equivalent to the line spacing for normal character printing. be done.

Next, in the case of high-quality character printing, Fig. 6 (a) and (b)
As shown in FIG. 3, the first printing is performed while moving the gear ridge 30 along the lead screw 29 at a dot spacing α/2 which is double the density for normal characters. This corresponds to the black circle shown in FIG. 6(b).

In this embodiment, one character is composed of 16 dots vertically and horizontally.

When the first printing is completed, the motor 28 is reversely rotated and the lead screw 29 is rotated 1/24 times from the home position in the paper feeding direction, thereby feeding the paper by a line interval of 172 vertical dots.

Next, even if the motor 28 is rotated in the forward direction to return the carriage 30 to the home position, the clutch gear 37 will not rotate in the opposite direction to the paper feed rotation direction, so the ratchet gear 36 will be 1/24 It holds the rotated position.

Further, the second printing is performed while moving the carriage 30 along the lead screw 29 at a dot interval α/2. When printing for one line is completed, which corresponds to the diagonal circle shown in FIG. 6(b), the motor 28 is rotated in the reverse direction, and the lead screw 29 is rotated once from the home position in the paper feeding direction.

At this time, the ratchet gear 36 and the pawls 41 and 42 of the ratchet roller 39 are not engaged until the ratchet roller 39 rotates 1/24, so the ratchet roller 39 does not rotate.Therefore, the ratchet gear 36 rotates an additional 23/24 rotation. I will do it.

After the first and second printing and paper feeding are completed,
This means that the paper has been fed by an amount corresponding to the line spacing.

A circuit block diagram and a flow chart thereof for carrying out the above control are shown in FIGS. 7 and 8, respectively.

FIG. 7 shows the configuration of a control system for controlling the recording apparatus shown in FIG. It is. The CPU 52 controls the recording heads 31 . The operation of the motor 28 is controlled to perform a recording operation. The recording control unit 50 is composed of devices such as a logic circuit and a driver, and receives a control signal D.
The recording head 31 is controlled by S, the motor 28 is controlled by a control signal MS, and both carriage feeding and paper feeding are controlled via the above-mentioned mechanism.

Further, at the home position of the carriage 30, a position detector 5 constructed of a photointerrupter or the like is installed.
1 is provided, and its output signal H3 is sent to the recording control section 5.
It is input to 0 and used for control described later.

Note that among the above-mentioned signals, the control signal PS includes information such as recording start, end, type of recorded characters, designation of recording quality, etc. If the CPU 52 is an external host device, the recording control signal P is sent in a predetermined format such as a control signal using a character code or an escape code and a character signal.
S is formed. Further, the control signal MS controls the motor 28 to rotate in the forward and reverse directions.As mentioned above, the motor 28 controls both carriage scanning and paper feeding, and one paper feed is controlled by the carriage 30. This is done by controlling the amount of movement further leftward in the figure than the home position, that is, toward the outside of the recording area.

Next, FIG. 8 shows the control operation of the CPU 52 as a flowchart.

When starting recording, the CPU 52 first determines the recording quality in step S1. If high-quality recording is to be performed, the process moves to step S2, and if high-quality recording is not to be performed, the process moves to step S9. In the normal quality recording in steps S9 to 512, first in step S9, as shown in relation to FIG.
12 dot pitches are set. These parameters are stored in a memory, register, etc. as flags for setting the drive method of the motor 28.

In step 510, the recording head 31 is caused to record dots with a pitch of L/12 in the vertical direction at one recording position using the control signal DS, and then the motor 28 is rotated via the control signal MS to rotate the carriage 30. The operation of moving in the horizontal direction at a pitch α is repeated to record one line.

Next, when recording of one line is completed in step Sll, the motor 28 is reversed and the carriage 30 is returned to the home position. At this time, the home position is detected by the position detection unit 5.
This is detected by the home position detection signal H5 outputted by No. 1.

Next, in step 2 312, the carriage is further moved to the left from the home position, and the ratchet gear 36 and the pawl 41 of the ratchet roller 39 are moved as described above.
42 to perform a paper feed operation for one line.

On the other hand, in the case of high-quality recording, first in step S2, α/2. Set a dot pitch of L/24 in the vertical direction.

Subsequently, in step S3, a first printing operation is performed. Here, α/
Recording is performed while moving the carriage 2 pitches.

Next, in step S4, the carriage return is performed in the same manner as in step Sll, and in step S5, the lead screw 29 is further turned 1/2 from the home position.
By rotating the paper 24 times, the paper is fed by 1/2 dot in the vertical direction.

In step S6, a second recording is performed in the same manner as in step S3. At this time, step S3. It goes without saying that the completion format of the control signal DS given to the recording pad 31 is controlled in advance so that characters (or images) can be formed by the recording performed in S6.

Subsequently, in step S7, a carriage return operation is performed in the same manner as in step S4, and then in step S8, the paper is fed at the paper feed pitch L for one line in the same manner as in step S12, and the paper is fed for one line. End recording. Here, in step S5, l
Since the paper is fed by /24 lines, when the paper feed operation is performed in step S8, a play of 1/24 line is intentionally created between the ratchet roller 39 and the pawls 41 and 42 of the ratchet gear 36. Therefore, as a result, the paper is fed by one line by two paper feeding operations, as in step S12 described above.

Although the recording operation for one line has been described above, by repeating each of the above steps, it is possible to record multiple lines of characters or images on the recording medium.

As described above, both the carriage scanning and paper feeding operations can be controlled by the rotation of one drive motor, and the scanning direction of the carriage and the paper feeding direction of the recording paper can be controlled at a pitch finer than the resolution of the dot matrix. As a result, it is possible to obtain a compact, inexpensive, and excellent recording device that can print one line in multiple recordings and can perform high-density dot matrix recording.

Note that the present invention is not limited to the above embodiments,
Can it be applied to various recording devices other than thermal printers, such as impact printers, inkjet printers, and wire dot printers? It goes without saying that the present invention can be similarly applied to the case of recording figures and other images other than characters and numbers. Furthermore, as the recording medium, various media such as plastic sheets can be used in addition to paper.

Furthermore, although an example has been shown in which the image quality is switched in two stages, the switching of the image quality is not limited to this, and it is also possible to switch the recording quality in more stages.

[Effects] As is clear from the above description, the present invention includes a recording head that records on a recording medium using a dot matrix, and a recording head that records on a recording medium with a pitch finer than the resolution of the dot matrix. means for transporting the recording medium at a pitch finer than the resolution of the dot matrix; and a common driving means for independently applying driving force to the scanning and transporting means.
When forming one recording line, the scanning means and the transport means are operated multiple times and a control means for recording is adopted, so the structure is simple and inexpensive, and the resolution is finer than the resolution of the recording head. It is possible to provide an excellent recording device that can perform dot matrix recording with high resolution.

[Brief Description of the Drawings] Fig. 1 is a perspective view showing the structure of a recording device according to the present invention;
2(a) and 2(b) are an enlarged plan view and an enlarged side view of the apparatus of FIG. 1, and FIG. 3(a). (b) is an enlarged plan view and an enlarged side view during carriage return, Fig. 4 is an enlarged plan view during paper feeding operation, and Fig. 5 (
a) and (b) are explanatory diagrams showing the operating state and recording state when recording normal characters, and Figures 6 (a) and (b) are paper feeding operations and recording when recording high-quality characters. FIG. 7 is a block diagram showing the structure of the recording control system, and FIG. 8 is a flowchart showing the recording control procedure of the CPU in FIG. 7. 20...Platen holder 21...Platen 23...Spring 26...Recording paper 28...
・Motor 29...Lead screw 30
... Carriage 31 ... Thermal head 36
...Ratchet gear 37...Clutch gear 39.
...Ratchet roller 51...Position detector 52...CPU Fig. 2 (
(1) Higekoki 8A-fμ〈Kuta Fig. 3 (Q) IK2 Fig. (b) 1≧241 Kikaku A,, 1 do to giant F7; I1 Rebishi 1 Kanto 3
Diagram (b)

Claims (1)

[Claims] a recording head that records on a recording medium using a dot matrix; a means for scanning the recording head on the recording medium at a pitch finer than the resolution of the dot matrix; and a means for scanning the recording medium with a pitch finer than the resolution of the dot matrix; a means for conveying at a pitch; a common driving means for independently applying driving force to the above-mentioned scanning and conveying means; What is claimed is: 1. A recording device comprising a control means for performing the following steps.