JP2002079656A - Recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stop a recording operation correctly at a driving limit temperature by correcting dispersions of a temperature sensor. SOLUTION: In detecting the temperature of a driving circuit 602 for driving a recording head 601 with the use of voltage drop-temperature characteristics in the forward direction of the diode (temperature sensor 603), when a power source of a body 20 of the recording apparatus is turned on, an output voltage value of the temperature sensor 603 at the room temperature is measured and stored into a storage part 24. At the recording operation time, an operation part 25 operates the output voltage value sequentially outputted from the temperature sensor 603 with stored contents of the storage part 204, and corrects dispersions of the temperature sensor 603. When the operated value reaches the driving limit value of the driving circuit 602, a control circuit 22 stops the recording operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for performing recording on a recording medium by a recording head such as an ink jet head.

[0002]

2. Description of the Related Art Conventionally, the temperature of a recording head or a drive circuit for driving the recording head is detected by a temperature detector, and when a temperature exceeds a predetermined temperature, a recording operation is stopped. The printing head or the drive circuit is protected by reducing the amount of printing operation per unit time.

As this temperature detector, Japanese Patent Application Laid-Open No. 3-140
As described in Japanese Patent Application Publication No. 248, there is a device that uses a diode and detects temperature based on its forward voltage drop-temperature characteristic. The configuration described in the above publication is for controlling the temperature of a heater that keeps the ink in the ink jet head warm.

This forward voltage drop-temperature characteristic is shown in FIG.
As shown by TS, a substantially linear inverse proportional relationship is shown, but the variation A of the output voltage with respect to the temperature is large for each product. Therefore, for example, if the detected output voltage is set to E1 in order to stop the operation at 125 ° C., 1
It does not stop even if the temperature exceeds 25 ° C., destroys the circuit, or frequently stops with a small number of recording pages even though it has the ability to perform a recording operation on many pages continuously. Sometimes.

An object of the present invention is to easily correct such a variation in characteristics and to accurately control the operation at a set temperature.

[0006]

In order to achieve the above object, a recording apparatus according to claim 1 includes a first temperature detector for detecting a temperature of a recording head or a driving circuit for driving the recording head; A storage unit for storing an output value of the temperature detector at a first predetermined temperature or a coefficient relating to the output value, and an output value of the first temperature detector based on an operation of the recording head or the driving circuit or A calculating unit that calculates based on a coefficient related to the output value and a value stored in the storage unit, and based on an output of the calculating unit when a second predetermined temperature higher than the first predetermined temperature is reached. A control circuit for restricting the operation of the recording head or the drive circuit.

The output value (eg, voltage) of the temperature detector at a first predetermined temperature, for example, room temperature (25 ° C.) or a coefficient relating to the output value is measured and stored in the storage unit. Then, by calculating based on the output value of the temperature detector accompanying the temperature rise due to the recording operation or a coefficient related to the output value and the value stored in the storage unit, the temperature-output value characteristic of the temperature detector is calculated. Is corrected based on the output value at the first predetermined temperature or a coefficient related to the output value. As a result, when the temperature reaches the second predetermined temperature higher than the first predetermined temperature, the operation of the recording head or the drive circuit can be restricted.

Here, limiting the operation may mean stopping the operation, but it is also possible to suppress the heat generation by reducing the amount of operation per unit time.

A recording apparatus according to a second aspect of the present invention is the recording apparatus according to the first aspect, further comprising a second temperature detector, wherein the output value at the first predetermined temperature or a coefficient relating to the output value is: The combination of the temperature detected by the second temperature detector when the power of the recording apparatus is turned on and the output value of the first temperature detector at that time, or its coefficient. That is, when the power is turned on, the combination of the temperature at that time and the output value of the first temperature detector or the coefficient thereof is stored, and based on the stored value, the temperature-output value characteristic of the first temperature detector is obtained as described above. Is corrected.

According to a third aspect of the present invention, in the recording apparatus according to the first aspect, when the first temperature detector applies a first predetermined voltage, the first temperature detector sets the first predetermined temperature and the second predetermined temperature.
In a temperature range including the predetermined temperature, the temperature-output voltage characteristic shows a substantially linear change, and the storage unit includes:
An output value of the first temperature detector or a coefficient relating to the output value when the first predetermined voltage is applied to the first temperature detector and at a predetermined first predetermined temperature. And relates to the output value of the first temperature detector or the output value when a second predetermined voltage lower than the first predetermined voltage is applied to the first temperature detector. The calculation unit calculates based on the coefficient and the value stored in the storage unit.

For example, when the drive circuit is controlled at a second predetermined voltage lower than the first predetermined voltage, the voltage applied to the first temperature detector also becomes the second voltage.
In some cases, the first temperature detector cannot output a voltage inversely proportional to the temperature at the predetermined temperature. Therefore, the first predetermined voltage is applied to the first temperature detector as described above, and the first predetermined voltage is applied to the first temperature detector.
By storing the output value of the first temperature detector or the coefficient relating to the output value at the predetermined temperature, the second predetermined temperature can be controlled even when the control is performed at a low second predetermined voltage. The output at allows precise control.

According to a fourth aspect of the present invention, in the recording apparatus according to any one of the first to third aspects, the recording head comprises:
The drive circuit and the first temperature detector are on a carriage that moves along the recording medium. In such a device, a diode can be used as the first temperature detector to be integrated with the drive circuit to form an integrated circuit, which can be suitably implemented. Further, in this case, it is possible to directly detect the temperature of the drive circuit.

According to a fifth aspect of the present invention, in the recording apparatus of the third aspect, the recording head, the driving circuit, the first temperature detector, and the storage unit are on a carriage that moves along a recording medium. . In such a device, a diode is used as a first temperature detector and an IC is integrated with a drive circuit.
When the recording head is replaced, the first temperature detector and the storage unit are also replaced, so that adjustment on the apparatus main body side due to variation in the first temperature detector becomes unnecessary. .

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the internal structure of an ink jet recording apparatus to which the present invention is applied. An ink jet recording head unit 600 is detachably mounted on a carriage 100 and scans in parallel with a recording medium 700. You. The carriage 100 is slidably supported by guide bars 110 and 120, and reciprocates along the guide bars by a belt 140 driven by a motor 37. A tank 150 containing ink to be supplied to the recording head unit 600 is detachably mounted on the carriage 100. The recording medium 700 includes the transport roller 16
By means of 0 and 170, the recording head unit 600 is held in parallel with the scanning direction and is conveyed in a direction perpendicular to the scanning direction.

FIG. 2 shows a schematic configuration for electrical control of the above-mentioned printing apparatus.
Includes a recording head 601, a drive circuit 602, and a temperature detector 603 integrally. The drive circuit 602 receives a control signal from a control circuit of the printing apparatus main body, and
To generate a driving voltage for driving the. Temperature detector 60
3 is for detecting the temperature of the drive circuit 602 in the present embodiment, but may be used for detecting the temperature of the print head 601 or the temperature of both the print head 601 and the drive circuit 602. Good. Temperature detector 603
Since the integrated circuit is manufactured integrally with the drive circuit 602, a diode formed on silicon of the integrated circuit is used.

The recording head 601 is preferably a recording head which selectively drives a large number of actuators to perform recording on a recording medium in a dot matrix system. Not only an ink jet system but also a thermal transfer or dot impact system can be applied.

The printing apparatus main body 20 receives print data sent from the outside by a control circuit 22 provided on a circuit board 21, generates a control signal for a print head, and outputs the control signal to a drive circuit 602. Further, the recording apparatus main body 20 has a second temperature detector 23 for detecting the ambient temperature of the surroundings.
And the output voltage value of the temperature detector 603 in the recording head unit at that time are stored in the storage unit 24. Then, the arithmetic unit 25 controls the driving circuit 6 during the recording operation.
The voltage value output from the temperature detector 603 in accordance with the temperature of the temperature sensor 02 and the contents stored in the storage unit 24 are calculated as described later,
The control circuit 22 is notified that the drive circuit 602 has reached the drive limit temperature. The control circuit 22 restricts, for example, stops the operation of the drive circuit 602 based on the notification.

The control circuit 22, the storage unit 24, and the arithmetic unit 2
Reference numeral 5 is a combination of a known CPU, ROM, RAM and a hardware circuit. A signal line transmitted from the control circuit 22 to the drive circuit 602 and the temperature detector 60
Although not shown in FIG. 1, the signal line transmitted from 3 to the apparatus main body is constituted by a known flexible printed circuit cable.

The second temperature detector 23 in the apparatus body 20
Is composed of a thermistor, a posistor, etc., and can generate an output corresponding to the temperature almost accurately as compared with the temperature detector 603 composed of a diode. The temperature detector 603 in the recording head unit is composed of a diode as described above, and performs temperature detection based on its forward voltage drop-temperature characteristic. The forward voltage drop-temperature characteristic shows a linear change as shown by TS in FIG. 3, but the variation A is large depending on the product.

For this reason, in this embodiment, correction is performed as follows.

When the power of the recording apparatus main body is turned on, the room temperature t (for example, 25 ° C.) detected by the second temperature detector 23;
The output voltage value (E2, E3, E4) of the temperature detector 603 in the recording head unit at that time is stored in the storage unit 24. The forward voltage drop-temperature characteristic has a constant slope of change even if there is a variation A depending on the product, so that the output value sequentially output from the temperature detector 603 during the recording operation and the content stored in the storage unit 24 are used. , An output corresponding to the actual temperature of the drive circuit 602 can be obtained.

For example, the output voltage value of the temperature detector 603 at room temperature t (25 ° C.) at power-on is B,
The numerical value (gradient) of the forward voltage drop-temperature characteristic of 3 is k,
When the detected temperature of the temperature detector 603 is x (° C.), the output voltage value y is obtained by y = B−k (x−t). Therefore, even if there is a variation A in the characteristics of the temperature detector 603, the output voltage value y corresponding to the temperature can be accurately obtained, and if the driving limit temperature is 125 ° C., x = 1
When the output voltage value y drops to 25 ° C., the operation of the recording head 601 can be stopped.

The calculation section 25 is set to perform the above calculation. Even when the room temperature at the time of turning on the power is other than 25 ° C., since the numerical value k is constant, B can be easily calculated. The value stored in the storage unit 24 may be a coefficient relating to a combination of the room temperature and the voltage value instead of the room temperature and the voltage value. If the measurement is performed at a constant room temperature, the room temperature does not need to be stored every time the power is turned on, and a certain value may be subtracted from the detected temperature x during the recording operation. Note that the numerical value k is stored in the storage unit 24 in advance.

When the recording head unit 600 is replaced, the characteristics of the temperature detector 603 change. However, as described above, by correcting the variation in the characteristics based on the calculation by the calculation unit 25, the recording is performed at an accurate temperature. The operation of the head 601 can be stopped.

Next, a second embodiment of the present invention will be described with reference to FIGS.
5 will be described.

The drive circuit 602 of the above embodiment is used with a 5 V power supply, and the characteristic TS of the temperature detector 603 is also when a voltage of 5 V is applied. In recent years, the voltage has been reduced, and the driving circuit 602 including the temperature detector 603 has been used at 3.3 V. In this case, FIG.
As shown by a broken line TSa, the characteristic of the temperature detector 603 is as follows.
It does not show a linear change near room temperature, and cannot perform the same correction as in the above embodiment.

In the second embodiment, as shown in FIG. 4, a recording unit 604 is provided in the recording head unit 600. The storage unit 604 is configured by a nonvolatile memory such as an EEPROM, and stores an output voltage value of the temperature detector 603 at a voltage of 5 V at substantially room temperature t (25 ° C.).

The operation of storing the output voltage value in the storage unit 604 is performed by applying a voltage of 5 V to the temperature detector 603 in a room maintained at room temperature t (25 ° C.) as shown in FIG. The output voltage value of the detector 603 is measured by the measuring device 50.
Then, the output voltage value is stored in the storage unit 60 by the writer 451.
Write to 4. Drive circuit 602 including temperature detector 603
Is used with a 3.3 V power supply during the recording operation, but is designed to withstand a voltage of 5 V as described above. Since the operation of storing in the storage unit 604 is performed in a factory, it is possible to measure a voltage value at a constant room temperature, and it is not necessary to store the temperature at the time of measurement as in the above-described embodiment. The temperature may be stored in the storage unit as needed.

The recording head unit 600 having the storage unit 604 storing the output voltage value at room temperature as described above
The output signal lines from the temperature detector 603 and the storage unit 604 are mounted in the recording apparatus main body 20 and connected to the calculation unit 25 of the recording apparatus main body 20.

In this state, since a voltage of 3.3 V is applied to the driving circuit 602 including the temperature detector 603, the temperature detector 603 does not show an output inversely proportional to the temperature near room temperature. The output is linearly inversely proportional to the temperature near the temperature. Therefore,
The calculation unit 25 can output an output corresponding to the actual temperature of the drive circuit 602 near the drive limit temperature based on the above equation, based on the output value of the temperature detector 603 during the recording operation and the storage content of the storage unit 604. The control circuit 22 can stop the transmission to the drive circuit 602 based on that.

Also in this embodiment, even when the recording head unit 600 is replaced, the temperature detector 6
Regardless of the variation of 03, the operation of the recording head 601 can be stopped accurately at the driving limit temperature.

In the above-described embodiments, the temperature and voltage values have been described by using specific numerical values. However, it is needless to say that these values can be appropriately changed upon implementation.

In both embodiments, the operation is stopped when the driving limit temperature is reached. However, the printing is performed by thinning out the printing dots in one scan of the printing head and by thinning out in the second scanning. Or perform printing per unit time by performing a printing operation only in one-way scanning where a printing operation was performed in normal reciprocating scanning, and pausing the printing operation in other one-way scanning. The amount of operation may be reduced to suppress heat generation.

Further, in the same manner as described above, the temperature of the recording head and the temperatures of the recording head and the drive circuit can be detected.

[0036]

As described above, according to the present invention, even if there are variations in the characteristics of the temperature detector, the variations can be easily corrected, and the operation of the recording head or the drive circuit can be accurately performed at the drive limit temperature. Can be restricted.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an internal configuration of a recording apparatus.

FIG. 2 is a block diagram illustrating a configuration of electrical control according to the embodiment of the present invention.

FIG. 3 is a forward voltage drop-temperature characteristic diagram of a temperature detector.

FIG. 4 is a block diagram illustrating a configuration of electrical control according to a second embodiment of the present invention.

FIG. 5 is a diagram for explaining a manufacturing process of the recording head unit according to the second embodiment.

[Explanation of symbols]

 601 Recording head 602 Drive circuit 603 Temperature detector 22 Control circuit 24 Storage unit 25 Operation unit

Claims (5)

[Claims] 1. A first temperature detector for detecting a temperature of a recording head or a driving circuit for driving the recording head, and an output value of the first temperature detector at a first predetermined temperature or its output. A storage unit for storing a coefficient relating to a value, and an output value of the first temperature detector based on an operation of the recording head or the drive circuit or a coefficient relating to the output value and a value stored in the storage unit. An operation unit that performs an operation; and a control circuit that restricts the operation of the recording head or the drive circuit based on an output of the operation unit when the temperature reaches a second predetermined temperature higher than the first predetermined temperature. Recording device. 2. The recording apparatus according to claim 1, further comprising a second temperature detector, wherein the output value at the first predetermined temperature or a coefficient relating to the output value is determined by turning on the power of the recording apparatus. A recording device which is a combination of the temperature detected by the second temperature detector and the output value of the first temperature detector at that time or a coefficient thereof. 3. The recording apparatus according to claim 1, wherein the first temperature detector includes a temperature range including the first predetermined temperature and the second predetermined temperature when a first predetermined voltage is applied. Wherein the temperature-output voltage characteristic shows a substantially linear change, and wherein the storage unit is configured to apply the first predetermined voltage to the first temperature detector and to determine the predetermined An output value of the first temperature detector at a predetermined temperature of 1 or a coefficient relating to the output value is stored, and a second predetermined voltage lower than the first predetermined voltage is stored in the first temperature. A recording device in which the calculation unit calculates based on an output value of the first temperature detector when applied to the detector or a coefficient related to the output value and a value stored in the storage unit. 4. The recording apparatus according to claim 1, wherein the recording head, the driving circuit, and the first temperature detector are on a carriage that moves along a recording medium. 5. The recording apparatus according to claim 3, wherein the recording head, the driving circuit, the first temperature detector, and the storage unit are on a carriage that moves along a recording medium.