JPH0569626A - Recorder - Google Patents

Abstract

PURPOSE:To provide a recorder capable of controlling a recording position by detecting it by a more simple structure. CONSTITUTION:A linear sensor 42 scans a scale 41 following motion of a carriage 7 on which a recording head 6 is mounted. Since narrow width slits 43 are provided to left and right both ends of the scale 41 and long width slits 44 are provided to the central part thereof, a pulse duty detecting circuit which the linear sensor 42 is equipped with receives a pulse signal of which a pulse duty ratio is different according to its slit width and detects a variation point of the pulse duty ratio. A home position is determined by counting a specific number of pulse (No) from this variation point. Thereby, the home position can be determined by a more simple structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording device, and in particular,
The present invention relates to a recording device capable of detecting the position of a recording head.

[0002]

2. Description of the Related Art Conventionally, a recording apparatus for serially recording on a recording sheet has been proposed in a form as shown in FIG. 8 (partially transparent view). In FIG. 8, 21 is a recording sheet,
Reference numeral 22 is a lower case that incorporates a circuit board, a paper feed mechanism, a head carrier mechanism, and the like, 23 is an upper case that is provided with a paper guide unit, and 24 is a paper guide for supplying the recording paper 21 to the recording apparatus. , 25 is an operation button panel for controlling paper feeding, power supply, etc., 26 is a recording head for recording on recording paper, 27 is a carriage for scanning the recording head 26, and 28 is movement of the carriage 27. A guide shaft for regulating 29 is a linear sensor for relatively detecting the position of the head carriage with a signal detector 29a and a scale 29b in which a position information pattern is recorded, and 30 is a recording and detecting the initial position of the recording head 26. This is a home position sensor for obtaining the timing of printing on the paper 21.

FIG. 9 is a block diagram showing the structure of the recording apparatus shown in FIG. In FIG. 9, 11 is a controller for controlling the entire recording apparatus, 12 is a head drive circuit for operating the recording head, 13 is a paper feed motor for feeding the recording paper, and 14 is a carriage for reciprocally scanning the carriage 27. A ridge motor, 15c is a motor drive circuit for operating the carriage motor 14, 15p is a motor drive circuit for operating a paper feed motor, 16 is an interface circuit for connecting an external device and the present recording device, 17 Is not limited as long as it is a host computer that controls the recording apparatus from the outside and has a predetermined interface.

The printing timing of the home position sensor 30, the linear sensor 29, and the recording head 26 provided in this recording apparatus is as follows.

FIG. 10 is a timing chart for explaining the relationship between the linear sensor 29 and the home position sensor 30. In the figure, the A phase is the output of the linear sensor 29 and the Z phase is the output of the home position sensor 30. The Z phase is a reference for the absolute position of the carriage 27 and is detected only once during the scanning movement of the carriage, and it and the linear sensor output A
The absolute position of the carriage is detected by adding or subtracting the phase signals to control the print timing of the recording head 26.

[0006]

However, in the above-mentioned conventional example, since the relative position detection of the linear sensor and the absolute position detection of the home position sensor are combined to control the print timing of the recording head, It had the following drawbacks. (1) One set of a linear sensor, a home position sensor, and a processing circuit thereof are required, which is a factor of cost increase. (2) Signal processing of two systems, home position and linear sensor, is required.

The present invention has been made in view of the above-mentioned conventional example, and an object thereof is to provide a recording apparatus capable of recording position detection control with a simpler configuration.

[0008]

In order to achieve the above object, the recording apparatus of the present invention has the following constitution. That is, a recording apparatus for recording an image on a recording medium by a recording unit, the conveying unit being opposed to the recording medium and conveying the recording unit by a reciprocating linear movement, and a parallel unit along the conveying unit. And a scale provided with slits having different widths at equal intervals near both ends and in the center of the range in which the conveying means conveys the recording means, and the recording means conveys the recording means. Then, based on the slit width change point detected by the detection means and the slit width change point detected from the slit provided in the scale, the home position of the recording means is determined. And a determining unit for performing the recording.

[0009]

According to the present invention having the above construction, when the recording means is conveyed by the conveying means, the change point of the width of the slit provided on the scale is detected from the scale provided in parallel with the conveying means, It operates to determine the home position of the recording means based on the change point.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[Schematic Description of Inkjet Printer] (FIG. 1) FIG. 1 is a block diagram showing the arrangement of an inkjet printer which is a typical embodiment of the present invention. In FIG. 1, elements common to those of the recording apparatus shown in the conventional example of FIG. 8 are designated by the same apparatus reference numerals, and description thereof will be omitted.

In FIG. 1, reference numeral 1 is a control unit for processing data received from the host computer 17, and
It controls the entire printer. Reference numeral 17 denotes a host computer, which transfers print data and various print control commands to the printer of this embodiment. An input interface circuit 18 receives the recording data from the host computer 17 and controls the interface.

The linear sensor 42 is provided with the pulse duty detection circuit 20 and counts the change points and the number of pulses of the pulse duty ratio of the pulses detected by the linear sensor 42.

In the control unit 1, reference numeral 2 denotes a CPU such as a microcomputer, which executes various controls according to a control program stored in the ROM 3. 4 is RAM
Then, it stores various data used as a work area of the CPU 2 and received from the host computer 17, and various data related to the control of the CPU 2. The RAM 4 includes a pulse counter 10 that counts the pulses detected by the linear sensor 42. Reference numeral 5 denotes a timer, which inputs time data or the like from the CPU 2 and measures the time corresponding to the time data, and causes the CPU 2 to generate, for example, an interrupt or the like to notify that the specified time has elapsed. There is.

Reference numeral 6 is a recording head for recording by the ink jet method, which is driven by a head drive circuit 12 in accordance with recording data from the controller 1. 7 is the record head 6
A carriage carrying a carriage driven by a carriage motor 8. The carriage motor 8 is a stepping motor in this embodiment, and is driven by a driver circuit 9.

[Description of Recording Unit (FIG. 2)] FIG. 2 is an external perspective view of the main portion of the recording unit of the ink jet printer according to this embodiment. In FIG. 2, 6 is an ink jet type recording head, and 7 is a carriage which carries the recording head 7 and reciprocates along the guide shafts 122 and 123 in the R and F directions indicated by arrows. A timing belt 121 is connected at both ends to the carriage 7 and is stretched between the pulleys 124 and 125. Reference numeral 8 denotes a carriage motor, which drives the carriage 7 via the timing belt 121. Reference numeral 21 denotes a recording sheet, which is held at a position facing the recording head 6 by a platen (not shown) or the like, and the recording is sequentially performed as the carriage 7 scans.

A linear sensor 42 is attached to the lower portion of the carriage 7, and the linear sensor 42 scans the scale 41 left and right in accordance with the reciprocating movement of the carriage 7. The scale 41 is provided with a slit 43 having a short width in the vicinity of both left and right ends thereof, and a slit 44 having a long width is provided in a central portion thereof. The linear sensor 42 is provided with a photo sensor (not shown). When the linear sensor 42 scans the scale 41, the slit 43,
The linear sensor 42 receives signals having different pulse widths by blocking the light emitted by the photosensor by the width of the width 44. Further, the pulse duty detection circuit 20 detects the change point of the pulse duty ratio from the received pulse. Upon detection of this change point, the value of the pulse counter 10 in the RAM 4 is reset, and every time a pulse is detected by the pulse duty detection circuit 20, the counter is incremented by 1 to count the number of pulses.

Further, if a constant (N ₀ ) is defined in the ROM 3, for example, after detecting the pulse duty ratio change point, the second pulse detection point is set as the home position. The home position can be detected from the value of N and N ₀ .

An example of drive conditions required for the carriage motor 8 during such a recording operation is as follows. When the recording density is 360 dots / inch, the rotation speed corresponding to the recording speed is 400 to 400. It is 1200 rpm.

[Home Position Determination Control (FIGS. 3 to 5)] Here, the home position determination control executed by the ink jet printer having the above-mentioned configuration will be described.
This will be described with reference to the time charts shown in FIGS.

FIG. 3 is a time chart showing the time change of the output of the linear sensor 42 provided in the printer device of this embodiment. This represents a pulse signal detected when the linear sensor 42 is moving from the left end of the scale 41 to the right as the carriage 7 moves. According to FIG. 3, the pulse duty changes at the boundary of FIG. This change point is detected by the pulse duty detection circuit 20 provided in the linear sensor 42, and the position after the pulse number (N ₀ ) set in the ROM 3 from the change point (b) of the pulse duty is set as the home position.

FIG. 4 is a time chart showing the time change of the output of the linear sensor 42 provided in the printer of this embodiment. This represents the pulse signal detected when the linear sensor 42 is moving from the left end of the scale 41 to the right end of the scale 41 with the movement of the carriage 7. According to FIG. 4, the pulse duty changes at the boundaries of (a) and (b) in the figure. Therefore, as in the case described with reference to FIG. 3, when the carriage 7 moves from the left end to the right end and again moves from the right end to the left end, the pulse counter 10 detects the change of the pulse duty at the point (b) in the figure. If the value is reset and the number of pulses is counted again from that point, the home position when the carriage 7 moves from the right end to the left end can be determined.

In this way, when the carriage 7 is moving forward (moving from the left end to the right end), the change point (a) is changed to R.
The position after the number of pulses (N ₀ ) set in OM3 is set as the first home position, and when the carriage 7 is returning (moving from the right end to the left end), the change point (b) is changed to the ROM3.
By setting the position after passing the number of pulses (N ₀ ) set to 2 as the second home position, it is possible to absorb a mechanical error or the like due to the reciprocation of the carriage 7 and realize a serial printer capable of highly accurate reciprocal printing. You can In addition,
By utilizing the fact that the slit width of the scale 41 is provided to some extent, the slit width is set outside the range where the recording paper 21 is set and printing is performed and at a place other than the duty ratio change point where home position detection is performed. You can combine short and wide widths to incorporate special information. For example, as shown in FIG. 5, low-duty pulses (n pulses) are generated in the area in the figure, m high-duty pulses are generated in the area, and high-duty is 1 and low-duty is 0 in the area. If you think, "100
A slit is provided so that a signal "1" is generated. By this, an arbitrary signal can be recorded and, for example, the manufacturing period of the signal device, the lot number, and the manufacturing factory can be controlled.

[Explanation of Bubble Jet (FIGS. 6 to 7)]
In this embodiment, as a method for recording on recording paper,
The serial bubble jet method, which is one of the inkjet recording methods, is used. Here, a bubble jet recording principle will be described in which a method of heating an ink liquid and ejecting ink using such an electrothermal converter is used.

FIG. 6 is an exploded view of the recording head 6 constituting the recording means, and FIGS. 7A to 7G are explanatory views of the bubble jet recording principle. Note that, regarding the typical configuration and principle thereof, for example, see US Pat. No. 4,723,129.
No. 4,740,796.

In FIG. 6, 209a is a heater board, which is an electrothermal converter (discharge heater) 2 on a silicon substrate.
09b, an electrode 2 made of aluminum or the like for supplying electric power thereto
And 09c are formed and disposed. A liquid path (nozzle) 20 for the recording liquid is supplied to the heater board 209a.
It is configured by bonding a top plate 209e having a partition wall for partitioning 9d. An ink cartridge for supplying ink to the recording head 6 is replaceably attached to a predetermined position of the apparatus.

The ink supplied from the ink cartridge through the conduit is filled in the common liquid chamber 209g in the recording head 209 from the supply port 209f provided in the top plate 209e, and the nozzle 209 is supplied from the common liquid output 209g.
guided into d. An ink ejection port 209h is formed in each of these nozzles 209d.
9h is formed by a predetermined pitch in the sheet conveying direction so as to face the recording sheet of the recording head 6.

In this embodiment, the recording head 6 having the above-described structure is mounted on a carriage which can reciprocate, and ink is ejected from the recording head 6 in synchronization with the movement of the carriage to carry out recording.

The principle of ink ejection in the bubble jet recording system will be described with reference to FIGS. 7 (a) to 7 (g). In the steady state, as shown in FIG.
The ink 40 filled in 09d has the surface tension and the external pressure in equilibrium at the ejection port surface. When the ink 40 is allowed to fly in this state, the electrothermal converter 2 in the nozzle 209d
09d is energized to cause the ink in the nozzle 209d to rapidly rise in temperature over nucleate boiling. Then, as shown in FIG.
As shown in (b), the ink adjacent to the electrothermal converter 209b is heated to generate minute bubbles (bubbles), the ink in the heated portion is vaporized to cause film boiling, and as shown in FIG. 7 (c). Thus, the bubble 41 grows rapidly.

When the bubble 41 grows to the maximum as shown in FIG. 7 (d), the ink droplet 4 is discharged from the ejection port in the nozzle 209d.
2 is extruded. When power supply to the electrothermal converter 209b is finished, the grown bubble 41 is cooled and contracted by the ink 40 in the nozzle 209d as shown in FIG. 7 (e). Ink droplets fly from the ejection port. Further, as shown in FIG. 7 (f), the ink comes into contact with the surface of the electrothermal converter 209b and is rapidly cooled, and the bubbles 41 disappear or contract to a substantially negligible volume. Then, when the bubble 41 contracts, as shown in FIG.
As shown in (g), the ink is supplied from the common liquid chamber 209g into the nozzle 209d by the capillary phenomenon to prepare for the next energization.

Accordingly, an ink image is formed on the recording sheet by reciprocally moving the carriage equipped with such a recording head and energizing the electrothermal converter 209b in synchronization with this movement according to the image signal. To be recorded.

As the constitution of the recording means, in addition to the combination of the discharge port, the liquid passage, and the electrothermal converter mentioned above, US Pat. No. 4,558,33 is arranged in the region where the heat acting portion is bent.
The materials disclosed in Japanese Patent No. 3 and JP-A-59-123670 can also be used.

Further, the above-mentioned recording means may supply ink to the recording head from an ink cartridge mounted in the recording device, or an ink storage chamber may be provided in the recording head so that the ink in the ink storage chamber is exhausted. If this happens, a replaceable recording head may be used so that the recording head is replaced.

As a form of the recording apparatus of the present invention,
In addition to being used as a printer as an image output terminal of information processing equipment such as a computer, it is also used as a copying apparatus in combination with a reader and the like, and as a facsimile apparatus having a transmission / reception function.

In this embodiment, the recording head of the recording means is the recording head for recording by the ink jet method, but the present invention is not limited to this. For example, a recording head for recording by a heat-sensitive method, a thermal transfer method, a wire dot recording method, an electrostatic recording method, or the like may be used.

As described above, according to this embodiment, the home position can be determined only by the linear sensor without using the home position sensor, and the recording apparatus having a simpler structure can be provided.

In the above-described embodiment, the case of controlling the stepping motor for driving the serial recording head has been described, but the present invention is not limited to this. For example, as a recording head, a line type thermal head is used. Even in the case of a printer that performs recording on a line-by-line basis using a head or the like, by using a stepping motor as a paper feed motor that conveys the recording sheet and performing the same conveyance control as in the present embodiment, the conveyance unevenness of the recording sheet is prevented. The recording quality can be improved by eliminating it.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0039]

As described above, according to the present invention, the home position can be obtained based on the scale and the detecting means without using a home position sensor or the like, and the device configuration can be simplified. There is an effect of becoming.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an ink jet printer device which is a typical embodiment of the present invention.

FIG. 2 is an external perspective view of a main part of a recording unit of the ink jet printer.

FIG. 3 is a timing chart of pulses detected by a linear sensor.

FIG. 4 is a timing chart of pulses detected by the linear sensor when the carriage 7 moves from the left end to the right end of the scale 41.

5 is a timing chart of pulses detected by a linear sensor when special information is incorporated in the scale 41. FIG.

FIG. 6 is an exploded view of the recording head according to the ink jet method.

FIG. 7 is a diagram explaining a recording principle by a bubble jet.

FIG. 8 is an external perspective view of a recording apparatus according to a conventional example.

FIG. 9 is a block diagram showing a configuration of a recording apparatus according to a conventional example.

FIG. 10 is a timing chart of a conventional example.

[Explanation of symbols]

 1 Controller 2 CPU 3 ROM 4 RAM 5 Timer 6 Inkjet Recording Head 7 Carrying 8 Carrying Motor 9 Driver 10 Pulse Counter 11 Controller 12 Head Drive Circuit 13 Paper Feed Motor 14 Carriage Motor 15c, 15p Motor Drive Circuit 16 Interface Circuit 17 Host Computer 20 Pulse duty detection circuit 21 Recording paper 22 Lower case 23 Upper case 24 Paper guide 25 Operation button panel 26 Recording head 27 Carriage 28 Guide shaft 29, 42 Linear sensor 29a Signal detector 29b, 41 Scale 30 Home position sensor

Claims (3)

[Claims] 1. A recording apparatus for recording an image on a recording medium by a recording means, the conveying means being opposed to the recording medium, and conveying the recording means by a reciprocating linear motion. Scales that are provided in parallel along each other and are provided with slits having different widths at equal intervals near both ends and in the center of the range in which the recording means is conveyed by the conveying means, and the recording means by the conveying means. When the means are transported,
From the slits provided on the scale, a detection unit that detects a slit width change point, and a determination unit that determines the home position of the recording unit based on the slit width change point detected by the detection unit; A recording apparatus having: 2. The recording apparatus according to claim 1, wherein the recording means includes an ink jet recording head for recording by ejecting ink. 3. The recording apparatus according to claim 2, wherein the recording head comprises a bubble jet recording head for recording by ejecting ink due to growth of bubbles.