JP2744575B2 - Recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus having a function of detecting the temperature of a recording head.

[0002]

2. Description of the Related Art Conventionally known printers can be broadly classified into two types depending on the printing method. One is L
As represented by BP (laser beam printer),
This is a page printer that uses a method of recording one pixel at a time. Another type of printer uses a print head in which print elements are arranged in a paper feed direction (a direction orthogonal to the head movement direction), and prints a plurality of pixels of the print head simultaneously or by dividing into several blocks. It is a serial printer where the method is.

[0003] The print head of such a serial printer is generally an ink jet system using a piezo element,
It is composed of an ink jet system utilizing thermal expansion of ink, a thermal transfer system, a thermal system, a dot impact system, a daisy wheel system, and the like. Further, in a serial printer, in an ink jet system utilizing thermal expansion of ink, a thermal transfer system, and a thermal system, a printing operation is performed by heating.

FIG. 2 is a sectional view for explaining an ink jet printing mechanism. In this figure, 201 is a print head main body, 202 is ink, 203 is a heater for heating ink, 204 is paper on a recording medium, and 205 is bubbles generated by heating the ink 202 with the heater 203. , 206 is the ejected ink droplet, 207 is paper 2
04 indicates the ink adhered to the surface.

Next, the printing operation will be described in order with reference to FIG. First, when a pulse-like voltage is applied to the heater 203 from a print head drive circuit (not shown) while the print head 201 is filled with the ink 202, the heater 2
The ink 202 in contact with 03 is locally rapidly heated and vaporized, so that the ink 202 foams to generate a bubble 205. At this time, the ink in front of the heater 203 is pushed forward by the energy of the expansion of the bubble 205, and the ink droplet 206
Is discharged outside the print head 201.

In this way, the ink droplet 206 is
Attached on the top to print characters or images.

At this time, if the size of the ejected ink droplets 206 is non-uniform, the print quality deteriorates and the image quality deteriorates due to uneven density of the printed matter. Therefore, in order to perform high-quality printing, it is desirable that the size of the ink droplet 206 is always uniform.

However, the size of the ink droplet 206 to be ejected largely depends on the viscosity of the ink, that is, the temperature of the ink. Therefore, the size of the ink droplet 206 is kept uniform by detecting the temperature of the ink and controlling the ejection energy by changing the pulse width of the pulsed voltage to be applied.

In such a case, as the ink temperature detecting means, a thermistor or a diode may be used.
In general, it is disposed in an ink liquid chamber (not shown) inside 1 and detects the amount of characteristic change due to these temperatures.

FIG. 3 is a diagram showing characteristics of a diode which is one of the above-mentioned temperature detecting means. The horizontal axis represents the ambient temperature T (° C.) of the diode, and the vertical axis represents a constant forward current flowing through the diode. Represents the forward voltage Vf (V) at the time of the above. However, the characteristics of the diode used in the description of the conventional example are as follows.

[0011]

## EQU1 ## Vf = 0.567 V ± 50 mV (If = 200
μA, T = 25 ° C.) Temperature change ΔVf = −2.37 mV (If = 200 μm)
A) In FIG. 3, reference numeral 301 denotes a diode used for temperature detection.
It shows "forward voltage vs. ambient temperature characteristic" when a forward constant current of 0 μA is passed, and it can be seen that the forward voltage Vf decreases as the temperature increases. Also, as shown in this figure, the diode forward voltage Vf is 0.2 at 25 ° C.
It is also found that the voltage is 567V.

Further, reference numeral 302 in FIG. 3 indicates a "forward voltage vs. ambient temperature characteristic" of a diode having a characteristic that the forward voltage variation when a constant forward current of 200 μA flows is 20 mV higher than that of a standard product. Represents.

Similarly, reference numeral 303 in FIG. 3 denotes a "forward voltage vs. ambient temperature characteristic" of a diode having a characteristic in which the forward voltage variation when a constant forward current of 200 μA flows is 20 mV lower than that of a standard product. Is represented.

FIG. 4 shows a conventional example of a circuit for detecting the ink temperature using a diode having the above characteristics (see FIG. 3).

In FIG. 4, reference numeral 101 denotes an ink jet print head (hereinafter, referred to as an IJ head) main body. Usually, a so-called nozzle for ejecting ink (not shown) shown in FIG. 64 are arranged.

Reference numeral 102 denotes an ink temperature detecting means using a diode which has been described above, and is usually arranged at least one in an ink liquid chamber (not shown).

Reference numeral 103 denotes a constant current circuit for supplying a constant forward current to the diode 102. 104 is a differential amplifier for amplifying the forward voltage of the diode 102.

Reference numeral 401 denotes a central processing unit for controlling a mechanism (not shown) and controlling the driving of the IJ head 101 necessary for performing a printing operation as a printer.

Reference numeral 402 denotes an input terminal for A / D conversion (analog / digital conversion), which is connected to an A / D converter (not shown) built in the central processing unit 401 and converts a voltage value input thereto into a digital signal. It is converted into a value and imported.

Reference numeral 403 denotes the diode 102 described above.
This is a means for providing correction data 403A for correcting the variation of the IJ head 101 to the central processing unit 401 by measuring the characteristics of the diode 102 of the IJ head 101 normally mounted in advance, classifying the characteristics into several ranks, and giving this rank. is there.

As a specific means for giving the correction data 403A, if the head is of a normal fixed type, it is performed by using a jig or a tool or a panel switch of a printer (not shown) in an assembling process in a factory. For the head, a storage element such as a ROM or some identifying means is added to the head itself, and the central processing unit 401 reads the correction data 403A when the head is mounted on the printer.

Next, the operation of the conventional example shown in FIG. 4 will be described.

An IJ head 10 is attached to a printer body (not shown).
When the power is turned on by a power switch (not shown) in a state in which the
02 is supplied with a constant current If of 200 μA. At this time, the forward voltage Vf of the diode 102 is amplified seven times by the differential amplifier 104,
The signal is input to a / D input terminal 402, converted into a digital value, taken into the central processing unit 401, and converted into temperature information inside the central processing unit 401.

At this time, the correction data 403A is given to the central processing unit 401 separately from the above operation. When the forward voltage Vf / temperature conversion inside the central processing unit 401, the correction data 403A is used. It is calculated based on the base.

FIG. 5 shows a characteristic curve when the forward voltage of the diode 102 taken into the central processing unit 401 from the A / D input terminal 402 (see FIG. 4) is converted into a temperature. In the figure, reference numeral 501 denotes the case of the diode having the standard characteristics described above, and reference numeral 502 denotes 200 μm.
A characteristic curve of a diode having a forward voltage variation of 20 mV higher than that of a standard product when a forward constant current of A flows, similarly, 503 indicates a forward voltage variation when a forward constant current of 200 μA flows. Represents a characteristic curve of a diode having characteristics 20 mV lower than that of a standard product. In the figure, reference numeral 504 denotes a temperature change characteristic region of the diode used in the conventional example.

[0026]

[SUMMARY OF THE INVENTION However, there is only a slight 8 2 9.5mV forward voltage as seen from the characteristic, substantially effective data area during the + 5V of the diode shown in FIG. 5, the so-called temperature characteristic change Although the dynamic range of the region 504 is small, the resolution at the time of A / D conversion cannot be fully utilized (for example, in the case of 8-bit A / D conversion,
Of the 256 steps, 44 steps are performed), and high-precision temperature detection cannot be performed.

Furthermore, since the dispersion of the characteristics of the diode 102 is corrected by the ranking, the accuracy is reduced due to the error in the ranking, and the dispersion is separately measured and the correction data is given. Could also occur.

For the above reasons, it has been difficult for the conventional method to detect the temperature accurately and accurately.

On the other hand, a highly accurate element such as a thermistor is known as a temperature detecting element. However, even if an attempt is made to detect the temperature of the printhead by providing such a thermistor in the printhead, the structure of the printhead may cause a problem.
It is difficult to build a thermistor as a temperature detecting element. In view of this, the above-described diode sensor and the like are known as such temperature detecting elements that can be easily incorporated into a recording head. However, the diode sensor has variations in individual output characteristics, and has an area in which the output depends on a temperature change and an area in which the output does not depend on the temperature change. It is inferior to a thermistor or the like in accuracy.
Therefore, in view of the above, an object of the present invention is to provide a print head with a temperature sensing element having an area whose output depends on a temperature change and an area that does not depend on a temperature change, and which may have variations in characteristics. It is another object of the present invention to provide a recording apparatus configured to obtain detection accuracy equivalent to that of a thermistor even in such a case.

[0030]

In order to achieve the above object, the present invention relates to a recording apparatus for recording on a recording medium by driving a recording head. A temperature detection element having an area that depends on temperature change and an area that does not depend on temperature change, and which is provided for detecting the in-machine temperature or the ambient temperature of the printing apparatus, and a temperature detection element that may have variations in characteristics; A temperature detection unit that depends on the temperature change and has substantially no area that does not depend on the temperature change, and a temperature value detected by the temperature detection element matches or approximates a temperature value detected by the temperature detection unit. A subtracting means for subtracting a predetermined value from a detection output of the temperature detecting element.

Here, it is possible to provide an amplifying means for amplifying the output of the temperature detecting element subtracted by the subtracting means. Further, the subtraction means may be configured to have an amplification function of amplifying the subtracted output of the temperature detection element. The recording head may be an ink jet recording head having a thermal energy generator for generating thermal energy used for discharging ink.

[0032]

According to the present invention having the above-described structure, a predetermined value is output from the detection output of the temperature detecting element so that the temperature value detected by the temperature detecting element matches or approximates the temperature value detected by the temperature detecting means. Since a subtraction unit for subtracting the value is provided, the variation in the output characteristics of the temperature detecting element is reduced, and the detection accuracy is improved.At the same time, the area that does not depend on the temperature change is removed from the output value, and only the area that depends on the temperature change Detection output. Therefore, by further amplifying the detection output, the dynamic range can be expanded, and the detection accuracy can be further improved.

Further, by amplifying a signal from which a region which does not depend on the temperature change characteristic of the temperature detecting element is removed, the dynamic range of the temperature change region can be arbitrarily expanded.

[0034]

Embodiments of the present invention will be described below in detail with reference to the drawings. Here, in each of the embodiments described below, an ink-jet serial printer will be described as an example similarly to the conventional example.

Embodiment 1 FIG. 1 is a block diagram showing a first embodiment of the present invention. In the figure, reference numerals 101, 102, 103, and 104 denote the same as those described in the section of the conventional example, which are an IJ head, a diode for temperature detection, a constant current circuit, and a differential amplifier with a gain of seven.

Numeral 105 denotes a differential amplifier for removing a temperature change-independent region of the forward voltage Vf of the diode 102 and expanding the dynamic range of the temperature change region, and has a gain of 2.86.

Reference numeral 106 denotes a central processing unit for controlling a mechanism (not shown) and controlling the driving of the IJ head 101 necessary for performing a printing operation as a printer.

An in-machine temperature sensor 107 uses a thermistor in this embodiment. Generally, thermist
Temperature detection accuracy is higher than diode sensors
No. A D / A converter (digital / analog converter) 108 outputs an analog voltage value under the control of the central processing unit 106.

Reference numerals 109 and 110 denote input terminals for A / D conversion (analog / digital conversion), which are connected to an A / D converter (not shown) built in the central processing unit 106 and input thereto. The voltage value is converted into a digital value and taken in.

Reference numeral 111 denotes a control line for the central processing unit 106 to control the D / A converter 108.

The operation of this embodiment will be described below according to the above configuration.

An IJ head 10 is attached to a printer body (not shown).
When the power is turned on by a power switch (not shown) in a state where 1 is mounted, a constant current If is supplied from the constant current circuit 103 to the diode 102 at 200 μA. At this time, the forward voltage Vf of the diode 102 is amplified seven times by the first differential amplifier 104 and then input to the non-inverting input terminal of the second differential amplifier 105.

At this time, a voltage corresponding to the diode correction data is output from the D / A converter 108 to the inverting input terminal of the second differential amplifier 105, A value obtained by subtracting the output value of the A converter 108 (that is, the forward voltage Vf of the diode 102)
The voltage value obtained by multiplying the gain of the differential amplifier 105 by 2.86 to the value after the temperature characteristic independent region in the inside is removed (that is, the dynamic range of the temperature characteristic dependent region in the forward voltage Vf of the diode 102 is expanded). Is input to the A / D conversion input terminal 109 of the central processing unit 106 and converted into a temperature inside the central processing unit 106.

Here, using FIG. 6 and Table 1 shown below, a specific method for correcting the variation of the forward voltage Vf of the diode 102 by the circuit of FIG. 1 and A / D
A specific method for converting a voltage value input to the conversion input terminal 109 into a head temperature will be described.

[0045]

[Table 1]

First, the forward voltage Vf of the diode 102
Will be described with reference to the flowchart of FIG.

When a power supply (not shown in FIG. 1) is turned on to the printer, the central processing unit 106 measures the temperature inside the printer by the internal temperature sensor 107 (step S1).

Next, the output of the D / A converter 108 is set to the minimum via the control line 111 of the D / A converter (step S2).

Thereafter, the central processing unit 106 increases the output of the D / A converter 108 by one level (step S).
3) At this time, the voltage value of the A / D conversion input terminal 109 is converted into a digital value and read, and is converted into a head temperature according to the contents shown in Table 1 (step S4).

Then, the result of the conversion is compared with the previously read internal temperature. If they are the same, the correction is completed (step S5: YES), and if they are different (step S5: N).
O) The output of the D / A converter 108 is increased again by one level (step S3), and after the same operation as above is repeated, the correction is made when the conversion result and the previously read internal temperature become the same. Complete the operation.

That is, when the conversion result of the head temperature and the previously read internal temperature become the same, the voltage value output from the D / A converter 108 becomes the correction value of the forward voltage Vf variation of the diode 102. It means that.

Therefore, after the correction is completed, the temperature of the IJ head 101 can be detected accurately by converting the voltage value input to the A / D conversion input terminal 109 into a temperature according to Table 1.

As described above, simultaneously with the completion of the correction, the removal of the temperature change-independent region in the forward voltage Vf of the diode is completed, and the expansion of the dynamic range of the temperature characteristic dependent region in the forward voltage Vf of the diode 102 is also completed. Will be done.

Next, with reference to FIG. 7, a description will be given of the removal of the temperature change-independent region in the forward voltage Vf of the diode. In the figure, reference numerals 501, 502, and 503 are the same as the conventional characteristic curves described with reference to FIG. As can be seen from FIG. 7, the areas originally intended to be detected are the characteristic curves 501 and 50.
A region which is only the gradient portion due to the temperature of 2,503 and which does not depend on the temperature change including the variation of the forward voltage Vf is unnecessary when detecting the temperature.

Therefore, it is only necessary to subtract a constant value corresponding to this area. In FIG. 7, reference numeral 701 in FIG. 7 denotes a characteristic curve after the removal, and 702 denotes a variation from 0 ° C. to 50 ° C.

A circuit for performing this subtraction processing is the second differential amplifier 105 in FIG.
08.

FIG. 8 shows the forward voltage V of the diode 102.
FIG. 7 is a diagram illustrating expansion of a dynamic range of a temperature characteristic dependent region in f. That is, the characteristic curve 7 in FIG.
01 is shown as a characteristic curve 801 showing the result of voltage amplification by the second differential amplifier 105 in FIG.

The above-mentioned table 1 is obtained by rewriting the characteristic curve 801 of the figure into a table.

Embodiment 2 FIGS. 9 and 10 are drawings for explaining a second embodiment of the present invention.

First, FIG. 9 is a diagram showing characteristics when the forward current value of a diode, which is one of the temperature detecting means, is changed. The horizontal axis represents the ambient temperature T (° C.) of the diode, and the vertical axis represents the diode. It represents the forward voltage Vf (V) when a constant forward current flows through the diode.

In FIG. 9, reference numeral 901 denotes “forward voltage vs. ambient temperature characteristic” when a constant forward current of 200 μA is applied to the diode 102 having a standard characteristic used for temperature detection. It can be seen that the forward voltage Vf decreases as it increases. From this figure, it can also be seen that this diode forward voltage Vf is 0.567 V at 25 ° C.

Further, reference numeral 902 in FIG. 9 represents "forward voltage vs. ambient temperature characteristic" when a forward constant current of 400 μA is passed through the diode. Similarly, in the figure, 90
3 shows “forward voltage vs. ambient temperature characteristic” when a forward constant current of 100 μA is passed.

From FIG. 9, it can be seen that the forward voltage Vf of the diode greatly varies in absolute value depending on the value of the forward current, but the variation characteristic due to temperature hardly changes.

FIG. 10 is a block diagram showing a second embodiment, in which variations in diodes are corrected using the characteristics shown in FIG. In the figure, parts having the same functions as those in FIG. 1 describing the first embodiment are given the same numbers. Reference numeral 1001 denotes a constant current circuit that can set an arbitrary current value via the D / A converter 108.

The operation of this embodiment according to the above configuration will be described below.

An IJ head 10 is attached to a printer body (not shown).
When the power is turned on by a power switch (not shown) in a state where 1 is mounted, a constant current If is supplied from the constant current circuit 1001 to the diode 102 at 200 μA. At this time, the forward voltage Vf of the diode 102 is amplified seven times by the first differential amplifier 104 and then input to the non-inverting input terminal of the second differential amplifier 105.

At this time, a voltage corresponding to the standard diode correction data is applied to the inverting input terminal of the second differential amplifier 105, and the output value of the differential amplifier 104 corresponds to the main correction data. A voltage value obtained by multiplying the gain of the differential amplifier 105 by 2.86 to a value obtained by subtracting the voltage (that is, a value obtained after removing the temperature characteristic independent region in the forward voltage Vf of the diode 102) (that is, the diode 102)
(The voltage value after expanding the dynamic range of the temperature characteristic dependent region in the forward voltage Vf) is input to the A / D conversion input terminal 109 of the central processing unit 106 and converted into a head temperature inside the central processing unit 106. Is done.

Next, referring to FIG. 11 and Table 1, a specific method for correcting the variation of the forward voltage Vf of the diode 102 by the circuit of FIG. 10 according to the second embodiment, and a method for A / D conversion will be described. A specific method for converting a voltage value input to the input terminal 109 into a head temperature will be described.

First, the forward voltage Vf of the diode 102
A method of correcting the variation will be described with reference to the flowchart of FIG.

When a power supply (not shown in FIG. 10) is turned on to the printer, the central processing unit 106
To measure the temperature inside the printer (step S1).
1).

Next, the output of the D / A converter 108 is set to a default value (a value such that the forward current of the diode 102 becomes 200 μA) via the D / A converter control line 111 (step S12). .

Thereafter, the voltage value of the A / D conversion input terminal 109 is converted into a digital value and read, and is converted into a head temperature according to the contents shown in Table 1 (steps S16 and S1).
9) If the temperature is the same as the internal temperature, the correction is completed (steps S14 and S17).

However, if the temperature is different from the internal temperature and the value indicated by the diode temperature sensor 102 is large (step S13 → S14), the central processing unit 106 reduces the output of the D / A converter 108 by one level (step S13). Step S
15: Decrease the forward current value).

On the other hand, when the temperature is different from the internal temperature and the value indicated by the diode temperature sensor 102 is small (step S
13 → S17), the central processing unit 106 increases the output of the D / A converter 18 by one level (step S1).
8: increase the forward current value).

Thereafter, the current value of the A / D conversion input terminal 109 at that time is converted into a digital value and read.
(Step S16, Step S16)
S19).

Then, the result of the conversion is compared with the previously read internal temperature. If they are the same, the correction is completed. If they are different, the output of the D / A converter 108 is increased or decreased by one level again. After repeating the same operation as described above, if the conversion result becomes equal to the previously read internal temperature, the correction operation is completed.

That is, when the conversion result becomes equal to the previously read internal temperature, the voltage value output from the D / A converter 108 becomes the forward voltage V
This is a correction value for f variation.

Therefore, after the correction is completed, the temperature of the head 101 can be detected by converting the voltage value input to the A / D conversion input terminal 109 into a temperature according to Table 1.

As described above, the correction is completed in the same manner as in the first embodiment, and at the same time, the removal of the temperature change-independent region in the forward voltage Vf of the diode is completed.
The dynamic range expansion of the temperature characteristic dependent region in the forward voltage Vf of 2 is also completed.

Embodiment 3 FIG. 12 is a block diagram for explaining a third embodiment.

In the first embodiment (see FIG. 1) and the second embodiment (see FIG. 10) described above, the gain of the amplifier is increased 7 times in the first stage 104 and is increased by 2 in the second stage 105. In the third embodiment, the gain of the amplifier in the first stage 1201 is set to 20 times, and the gain of the second stage 1202 is set to 1 in the third embodiment. The setting of the gain in the third embodiment includes the first and second gains.
The present embodiment is also applicable.

However, such a configuration generally requires a higher power supply voltage by the amplifier.

The characteristics of the diode, the gain of the amplifier, etc., which have been described, are not limited to those described above. The purpose / configuration of the detection temperature range, the detection accuracy, the power supply voltage of the circuit system, etc. It is needless to say that it can be arbitrarily selected and set according to.

Embodiment 4 FIG. 13 is a block diagram for explaining a fourth embodiment of the present invention.

In the first embodiment (see FIG. 1) and the second embodiment (see FIG. 10), the description has been made with the automatic adjustment configuration using the D / A converter 108. By using a means for recognizing the temperature by some means (such as a thermometer 1302), the D /
It is also possible to replace the A converter 108 with a variable resistor 1304 to perform artificial adjustment in a manufacturing process or the like.

It is clear that this embodiment can be applied to the first embodiment, the second embodiment, and the third embodiment.

FIG. 14 is a main schematic view of an ink jet printer incorporating each of the embodiments described above. In the figure, reference numeral 16 denotes an ink jet head (recording head) having a nozzle group for discharging ink while facing the recording surface of the recording paper sent on the platen 124. Reference numeral 116 denotes a carriage for holding the recording head 16, which is connected to a part of a driving belt 118 for transmitting the driving force of a driving motor 117, and is slidable with two guide shafts 119A and 119B disposed in parallel with each other. By doing
The recording head 16 can reciprocate over the entire width of the recording paper. During this reciprocation, the recording head 16 records an image corresponding to the image data on the recording paper. The recording paper is conveyed by a predetermined amount every time one main scan is completed, and a sub-scan is performed.

Reference numeral 126 denotes a head recovery device, which is disposed at one end of the moving path of the recording head 16, for example, at a position facing the home position. The head recovery device 126 is operated by the driving force of the motor 122 via the transmission mechanism 123, and the recording head 16 is capped. In connection with the capping portion of the head recovery device 126 to the recording head 16 by the cap portion 126A, ink absorption (suction recovery) is performed by an appropriate suction means (for example, a suction pump) provided in the head recovery device 126, As a result, an ejection recovery process such as removing the thickened ink in the ejection port by forcibly discharging the ink from the ejection port is performed. Also, by performing capping at the end of recording or the like, the recording head is protected. Such an ejection recovery process is performed when the power is turned on, when the print head is replaced, or when the printing operation is not performed for a certain period of time or the like.

Reference numeral 131 denotes a blade disposed on the side surface of the head recovery device 126 as a wiping member formed of silicone rubber. The blade 131 is held in a cantilever form by a blade holding member 131A, and like the head recovery device 126, a motor 122 and a transmission mechanism 123 are provided.
And the engagement with the ejection surface of the recording head 16 becomes possible.

Thus, at an appropriate timing in the recording operation of the recording head 16 or the head recovery device 1
After the ejection recovery process using the recording head 26, the blade 131 is protruded into the movement path of the recording head 16, and the dew condensation, wetness, dust, and the like on the ejection surface of the recording head 16 are wiped off as the recording head 16 moves.

Note that the first to fourth embodiments described so far.
In, the inkjet printer of the inkjet system has been described, but is not limited thereto.
The present invention can be easily applied to a printer that prints by utilizing the action of thermal energy, such as a thermal transfer method and a heat-sensitive method, which are described in the conventional examples, regardless of the method.

In each of the embodiments described above,
To constitute a temperature detecting means of the head with the diode, but as described can have you in the conventional example, a thermistor or the like, it is possible to apply the present invention as long as the device for generating a characteristic change with temperature.

(Others) It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for ink ejection, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

The configuration of the recording head is not limited to a combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned specifications. U.S. Pat. No. 4,558,333 and U.S. Pat.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, a recording head fixed to the apparatus main body or an electric connection with the apparatus main body or ink from the apparatus main body is mounted on the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

Further, it is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, and the like as the configuration of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The type and number of recording heads to be mounted are, for example, not only those provided for one color ink but also a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start solidifying when it reaches the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is held as a liquid or solid substance in the concave portion or through hole of the porous sheet and faces the electrothermal converter. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

Further, the form of the ink jet recording apparatus of the present invention is not limited to those used as image output terminals of information processing equipment such as computers, copying apparatuses combined with readers and the like, and facsimile apparatuses having a transmission / reception function. It may take a form.

[0102]

As described above, according to the present invention, the detection output of the temperature detecting element is adjusted so that the temperature value detected by the temperature detecting element matches or approximates the temperature value detected by the temperature detecting means. Since a subtraction unit for subtracting a predetermined value is provided, variation in output characteristics of the temperature detecting element is reduced, and detection accuracy is improved. At the same time, a region that does not depend on temperature change is removed from the output value, and a region that depends on temperature change is removed. It can be a detection output consisting of only Therefore,
Further, by amplifying the detection output, the dynamic range can be expanded, and the detection accuracy can be further improved.

Therefore, according to the present invention, it is possible to realize a printer capable of forming high-quality images without printing unevenness / density unevenness.

Further, as described in the first and second embodiments, by employing a configuration using a D / A converter and the like, adjustment work in the manufacturing process can be eliminated, and
A printhead detachable printer can easily cope with automatic correction of printhead temperature sensor characteristics.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the principle of ink ejection by an inkjet method.

FIG. 3 is a diagram showing “forward voltage vs. temperature characteristics” of a diode.

FIG. 4 is a block diagram showing a conventional technique.

FIG. 5 is a diagram showing “forward voltage vs. temperature characteristics” of a diode.

FIG. 6 is a flowchart illustrating the operation of the first embodiment.

FIG. 7 is a diagram showing “forward voltage versus temperature characteristics” of a diode.

FIG. 8 is a diagram showing “forward voltage versus temperature characteristics” of a diode.

FIG. 9 is a diagram showing “forward voltage versus temperature characteristics” of a diode.

FIG. 10 is a block diagram showing a second embodiment.

FIG. 11 is a flowchart illustrating the operation of the second embodiment.

FIG. 12 is a block diagram showing a third embodiment.

FIG. 13 is a block diagram showing a fourth embodiment.

FIG. 14 is a schematic view of an ink jet printer to which the present invention is applied.

[Explanation of symbols]

 Reference Signs List 101 inkjet (IJ) 102 print head temperature sensor 103, 1001 constant current circuit 104, 105 differential amplifier 106 central processing unit 107 in-machine temperature sensor 108 D / A converter 109, 110 A / D conversion input terminal

Claims (4)

(57) [Claims] 1. A recording by driving the recording head
A recording apparatus for recording on the body, the al provided in the recording head is, the output is dependent on the temperature change
It has an area and an area that does not depend on temperature changes,
A temperature detecting element may have attached, provided we are to detect the internal temperature or ambient temperature of the recording apparatus, the output is dependent on temperature change, the temperature change
Temperature detecting means having substantially no independent area; and a temperature value detected by the temperature detecting element is the temperature detecting means.
So that the temperature matches or approximates the detected temperature value.
Subtracting means for subtracting a predetermined value from the detection output of the degree detecting element
Recording apparatus characterized by comprising and. 2. The method according to claim 1, wherein
Amplifying means for amplifying the subtracted output of the temperature sensing element
Recording apparatus characterized by comprising a. 3. The method according to claim 1, wherein said subtracting means includes a subtracting means.
An amplification function for amplifying the calculated output of the temperature sensing element.
Recording apparatus characterized by comprising. 4. The method according to claim 1, wherein
The recording head is used to eject ink
B having a heat energy generator for generating heat energy
Recording device characterized by being an ink jet recording head
Place.