Arithmetic unit and ink jet printer

Abstract

To provide a technique advantageous for appropriately continuing temperature detection while reducing power consumption in a power saving mode.SOLUTION: An arithmetic unit according to the present invention comprises a temperature detection unit and performs arithmetic operations on a detection result from the temperature detection unit. The arithmetic unit incudes a first processing unit that performs arithmetic processing on the basis of first voltage, and a second processing unit that performs arithmetic processing on the basis of second voltage. The arithmetic unit includes, as an operation mode, a first mode in which both the first voltage and the second voltage are supplied, and a second mode in which supply of the first voltage is suppressed. The temperature detection unit outputs the detection result to the first processing unit in the first mode and outputs the detection result to the second processing unit in the second mode.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to computing devices. [Background technology]

[0002] Electronic devices that require temperature control or temperature management are generally provided with a temperature detection device for detecting the temperature of the object (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-2081 Summary of the Invention [Problem to be solved by the invention]

[0004] Some electronic devices that operate based on multiple power systems require temperature detection to continue even in a power-saving mode in which some of the power systems are suppressed. Therefore, there is a general demand for technology that can appropriately continue temperature detection while reducing power consumption in the power-saving mode.

[0005] The present invention was made in response to the inventor's recognition of the above-mentioned problems, and aims to provide a technology that is advantageous for appropriately continuing temperature detection while reducing power consumption in a power saving mode. [Means for solving the problem]

[0006] One aspect of the present invention relates to a computing device, the computing device comprising: A computing device including a temperature detection unit and configured to calculate a detection result of the temperature detection unit, a first processing unit and a second processing unit that perform calculations on the detection results; The operation modes include a first mode and a second mode in which the power consumption of the arithmetic unit is smaller than that of the first mode, An electric element whose resistance value varies with temperature; a selector capable of selectively connecting a first electrical path connected to the first processing unit and a second electrical path connected to the second processing unit. It is characterized by: [Effects of the Invention]

[0007] According to the present invention, it is possible to reduce power consumption in the power saving mode while continuing to appropriately detect temperature. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a calculation device according to an embodiment. [Figure 2] 10 is a flowchart showing the control content when transitioning from a normal mode to a power saving mode. [Figure 3] 10 is a flowchart for executing a temperature detection process in a power saving mode. [Figure 4] 10 is a flowchart showing the control content when transitioning from a power saving mode to a normal mode. [Figure 5] 10 is a flowchart showing the control content when transitioning from a normal mode to a power saving mode. [Figure 6] 10 is a flowchart showing the control content when transitioning from a power saving mode to a normal mode. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the claimed invention. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] (First embodiment) 1 shows an example of the configuration of a computing device 10 according to the first embodiment. The computing device 10 performs computational processing on the temperature detection results, details of which will be described later. The computing device 10 is applicable to a variety of electronic devices that include a drive device that performs drive control based on the computation results, and can be applied, for example, to an inkjet printer that can eject ink using thermal energy using an electrothermal conversion element.

[0011] The arithmetic device 10 includes a first processing unit 11, a second processing unit 12, a PMIC (power management integrated circuit) 13, a temperature detection unit 14, a nonvolatile memory 15, a power key 16, and an external power supply connection unit 25. The processing unit 11 is assumed to use an ASIC (application specific integrated circuit) and performs predetermined arithmetic processing based on a voltage VDD1. The processing unit 12 is assumed to use an MCU (microcontroller unit) and performs other arithmetic processing based on a voltage VDD2 that is smaller than the voltage VDD1.

[0012] The processing unit 11 includes a CPU (Central Processing Unit) 18 and a detection result acquisition unit 17. The processing unit 12 includes a CPU 19, a detection result acquisition unit 20, a memory 21, a PMIC control unit 22, a selector control unit 23, and an operation input detection unit 24. Although details will be described later, the processing units 12 and 12 perform predetermined arithmetic processing using the CPUs 18 and 19 based on the detection results received from the temperature detection unit 14 by the detection result acquisition units 17 and 20, respectively.

[0013] The processing units 11 and 12 can also perform arithmetic processing for driving or controlling predetermined objects. The processing unit 11 is configured with a larger proportion of analog circuits than the processing unit 12, and the processing unit 11 generally consumes a relatively large amount of power. Hereinafter, the processing unit 11 will be referred to as the ASIC 11, and the processing unit 12 will be referred to as the MCU 12, but the processing units 11 and 12 may each be referred to as a driving unit, a control unit, etc., or may be additionally distinguished by being designated as a first, second, main, sub, etc. The ASIC 11 and the MCU 12 can communicate with each other using a known method such as I2C (Inter-Integrated Circuit) or SPI (Serial Peripheral Interface).

[0014] The computing device 10 has two operating modes: a normal mode (first mode) and a power-saving mode (second mode). In the normal mode, the ASIC 11 operates based on the voltage VDD1 and the MCU 12 operates based on the voltage VDD2. In the power-saving mode, the ASIC 11 enters a sleep state, while the MCU 12 continues to operate based on the voltage VDD2. Incidentally, "voltage" can indicate a potential relative to the ground potential, but in consideration of the purpose of the above-mentioned operation mode, it may be rephrased as "power" which further includes the amount of current supply.

[0015] The PMIC 13 includes a first voltage generation unit (VDD1 generation unit) 26 and a second voltage generation unit (VDD2 generation unit) 27. The voltage generation units 26 and 27 generate voltages VDD1 and VDD2, respectively, based on an external voltage supplied via an external power supply connection unit 25. That is, in the PMIC 13, both voltages VDD1 and VDD2 are generated in the normal mode, and in the power saving mode, voltage VDD2 is generated while generation of voltage VDD1 is suppressed. The PMIC 13 further includes a voltage generation control unit 28 for controlling the supply or stop of power to each of the generated voltages VDD1 and VDD2. In this embodiment, the voltage generation control unit 28 can control each of the voltage generation units 26 and 27 based on a control signal received from the PMIC control unit 22 of the MCU 12.

[0016] For ease of understanding, the description will be given here assuming that the voltage VDD1 is not generated in the power saving mode, but the ASIC 11 may partially operate with less power than in the normal mode.

[0017] The temperature detection unit 14 includes a selector 30, resistive elements 31 and 32, and an electric element 29. A multiplexer is used for the selector 30, and in this embodiment, the selector 30 includes outputs B1 and B2 and an input S. The resistive element 31 has one end connected to a voltage VDD1 and the other end connected to an output B1 of the selector 30. The resistive element 32 has one end connected to a voltage VDD2 and the other end connected to an output B2 of the selector 30. In this configuration, the resistive elements 31 and 32 can also be expressed as pull-up resistors. Furthermore, the electric element 29 may be configured so that its resistance value varies with temperature, and examples thereof include a resistive element and a rectifying element, and a thermistor may typically be used. One end of the electric element 29 is connected to the input S of the selector 30, and the other end is connected to a ground line (grounded). For example, if the electric element 29 is a rectifying element, the anode side of the electric element 29 is connected to the input S of the selector 30, and the cathode side is connected to the ground line.

[0018] The selector 30 connects the input S to one of the outputs B1 and B2 based on a control signal from the selector control unit 23. For example, when the input S and the output B1 are connected, the selector 30 outputs the divided value of the voltage VDD1 based on the resistance ratio of the elements 29 and 31 (i.e., the voltage Vf generated in the electrical element 29) as the temperature detection result to the detection result acquisition unit 17 of the ASIC 11. When the input S and the output B2 are connected, the selector 30 outputs the divided value Vf of the voltage VDD2 based on the resistance ratio of the elements 29 and 32 as the temperature detection result to the detection result acquisition unit 20 of the MCU 12.

[0019] In the ASIC 11, the detection result acquisition unit 17 performs analog-to-digital conversion on the detection result received from the temperature detection unit 14, and the CPU 18 performs signal processing on the detection result thus obtained as a digital signal. Similarly, in the MCU 12, the detection result acquisition unit 20 performs analog-to-digital conversion on the detection result received from the temperature detection unit 14, and the CPU 19 performs signal processing on the detection result thus obtained as a digital signal. These signal processes may be simply referred to as "temperature detection processing" in the following description. Even under the same environment, an error may occur between the voltage division value Vf input to the detection result acquisition unit 17 of the ASIC 11 and the voltage division value Vf input to the detection result acquisition unit 20 of the MCU 12. This error is due to, for example, a difference between the voltages VDD1 and VDD2 generated by the PMIC 13, a difference in the resistance values ​​of the resistor elements 31 and 32 due to manufacturing variations, etc.

[0020] In the normal mode, information or data can be written to and read from the nonvolatile memory 15 based on the voltage VDD1, and the nonvolatile memory 15 can be used even after returning from the power saving mode to the normal mode. The nonvolatile memory 15 may be a known storage device such as a flash memory.

[0021] The power key 16 functions as an operation input unit for switching the above-mentioned operation modes. For example, if the power key 16 is pressed during normal mode, the mode transitions to power saving mode, and if the power key 16 is pressed during power saving mode, the mode transitions to normal mode. As will be described in detail later, the MCU 12 detects whether the power key 16 has been pressed using the operation input detection unit 24, and performs temperature detection processing in response to the detection. The operation input for switching the operation mode is not limited to pressing the power key 16, but may be performed in other ways.

[0022] The arithmetic device 10 further includes a notification unit 91 for making a predetermined notification. The notification unit 91 may be a light source, a sound source, or a signal for outputting an image to a display.

[0023] In normal mode, the ASIC 11 generally consumes a relatively large amount of power, but this power consumption can become even greater as the operating frequency and circuit size increase. The temperature detection process is preferably performed by the ASIC 11, which operates based on the voltage VDD1, for the purpose of detecting the temperature with high accuracy, for example. On the other hand, in the power-saving mode, the voltage VDD1 is not supplied to the ASIC 11, and / or in order to prevent unnecessary activation of the ASIC 11, the temperature detection process is performed by the MCU 12 in this embodiment. This allows the temperature detection process to be continuously performed even in the power-saving mode.

[0024] 2 is a flowchart showing the control contents when transitioning from the normal mode to the power saving mode. Before the transition, the input S and the output B1 of the selector 30 are connected (the output B1 is selected), and the temperature detection result by the temperature detection unit 14 is output to the ASIC 11 (the detection result acquisition unit 17).

[0025] In step S101 (hereinafter simply referred to as "S101"; the same applies to other steps described later), in response to the operation input detection unit 24 detecting that the power key 16 has been pressed, a transition to the power saving mode is initiated. In S102, in response to detecting the depression of the power key 16, the MCU 12 notifies the ASIC 11 that a transition to the power saving mode is being initiated. In S103, in response to the notification, the ASIC 11 executes temperature detection processing based on the voltage Vf of the output B1 of the selector 30 using the detection result acquisition unit 17, and stores the result in the nonvolatile memory 15 as the detected temperature in S104. In S105, the ASIC 11 outputs to the MCU 12 a command to transition to the power saving mode. In S106, in response to the transition command, the MCU 12 switches the connection destination of the input S of the selector 30 to the output B2 by the selector control unit 23, thereby generating the divided voltage value Vf based on the voltage VDD2 at the output B2. In S107, in response to the switching of the connection destination of input S, MCU 12 executes temperature detection processing based on the voltage Vf of output B2 of selector 30 using detection result acquisition unit 20, and in S108 outputs the result to ASIC 11 as the detected temperature.

[0026] In S109, the ASIC 11 calculates the difference between the detected temperature obtained in S103 and the detected temperature received from the MCU 12 in S108, and determines whether the difference satisfies a criterion (for example, whether it is within an allowable range). If the difference satisfies the criterion, the process proceeds to S111, and if the difference is equal to or greater than the criterion, the process proceeds to S110.

[0027] In S110, it is determined that the difference between the temperature detected by the ASIC 11 and the temperature detected by the MCU 12 is equal to or greater than a reference temperature, and a predetermined notification is made by the notification unit 91. This notification may be made to the user, or may be made by shutting down or rebooting the computing device 10. Thereafter, this flowchart ends in S113, and the transition to the power saving mode is suppressed.

[0028] In S111, the ASIC 11 determines that the difference between the temperature detected by the ASIC 11 and the temperature detected by the MCU 12 satisfies the criteria, and stores information indicating this difference in the nonvolatile memory 15 as difference information. In S112, the MCU 12 outputs a control signal (pause signal) to deactivate the voltage generation unit 26 via the PMIC control unit 22, and suppresses generation of the voltage VDD1 via the power supply control unit 28. After that, in S113, this flowchart ends, i.e., the transition to the power saving mode is completed.

[0029] 3 is a flowchart for performing temperature detection processing in the power saving mode. After the transition, the input S and output B2 of the selector 30 are connected (the output B2 is selected), and the temperature detection result by the temperature detection unit 14 is output to the MCU 12 (the detection result acquisition unit 20). In S201, after transitioning to the power saving mode, the MCU 12 starts the temperature detection process. In S202, the detection result acquisition unit 20 acquires the detection result, and in S203, the acquired detected temperature is stored in the memory 21. In S204, the process waits for a predetermined time (for example, one minute).

[0030] In S205, it is determined whether the power key 16 has been pressed, which indicates a return from the power saving mode to the normal mode. If the power key 16 has been pressed, the process proceeds to S206, where the normal mode is restored and this flowchart ends. On the other hand, if the power key 16 has not been pressed, the process returns to S202, i.e., the temperature detection process by the MCU 12 is executed at a predetermined interval.

[0031] Here, a transition from the power saving mode to the normal mode is expressed as a return, whereas a transition from the normal mode to the power saving mode is expressed as a return, but either may be expressed as a transition.

[0032] 4 is a flowchart showing the control content when the computing device 10 returns from the power saving mode to the normal mode. Before the return, the input S and the output B2 are connected in the selector 30 (the output B2 is selected), and the temperature detection result by the temperature detection unit 14 is output to the MCU 12 (the detection result acquisition unit 20).

[0033] In S301, in response to the operation input detection unit 24 detecting that the power key 16 has been pressed, a transition to the normal mode is initiated. In S302, upon transition to the normal mode, the MCU 12 controls the voltage generating unit 26 via the PMIC control unit 22 to start generating the voltage VDD1.

[0034] In S303, the MCU 12 switches the connection destination of the input S of the selector 30 to the output B1 by the selector control unit 23, thereby generating a divided voltage value Vf based on the voltage VDD1 at the output B1. That is, the ASIC 11 executes the temperature detection process by the detection result acquisition unit 17 based on the voltage Vf of the output B1.

[0035] In S304, the ASIC 11 acquires from the MCU 12 information indicating the transition of the detected temperature in the power saving mode acquired in S201. In S305, the detection result acquired by the detection result acquisition unit 20 of the MCU 12 is corrected based on the transition of the detected temperature in the power saving mode obtained in S304 and the difference information stored in the nonvolatile memory 15 in S111. This makes it possible to eliminate an error that may occur between the detected temperature in the ASIC 11 and the detected temperature in the MCU 12. In S306, the temperature detection process by the ASIC 11 is restarted, and this flowchart ends, that is, the return to the normal mode is completed.

[0036] According to this embodiment, in normal mode, the ASIC 11 performs temperature detection processing, and when transitioning to power saving mode, a temperature detection error that may occur between the ASIC 11 and the MCU 12 is stored as difference information in the nonvolatile memory 15. In power saving mode, the MCU 12 performs temperature detection processing, and the result is stored in the memory 21. When returning to normal mode, the ASIC 11 receives the detection result stored in the memory 21 from the MCU 12 and corrects it based on the difference information (the above-mentioned error) stored in the nonvolatile memory 15. This makes it possible to appropriately achieve continuous execution of the temperature detection processing regardless of the operating mode.

[0037] (Second embodiment) FIG. 5 is a flowchart showing another example of the control content when transitioning from the normal mode to the power saving mode in the second embodiment. S401 to S403 are respectively similar to S101 to S103 (see FIG. 2) in the first embodiment described above.

[0038] In S404, the ASIC 11 transmits the result of the temperature detection process acquired by the detection result acquisition unit 17 in S403 as a detected temperature together with a command to transition to the power saving mode to the MCU 12. In S405, the MCU 12 stores the transmitted detected temperature in the memory 21.

[0039] Steps S406 and S407 are the same as steps S106 and S107, respectively, in the first embodiment. Steps S408 and S409 are the same as steps S109 and S110, respectively, in the first embodiment. In S410, the MCU 12 stores the difference between the detected temperatures of the ASIC 11 and the MCU 12 as difference information in the memory 21 (that is, this embodiment differs from S111 in that the difference information is stored in the nonvolatile memory 15). S411 and S412 are similar to S112 and S113 in the first embodiment, respectively.

[0040] That is, the main difference is that, while the first embodiment utilizes the nonvolatile memory 15 to perform correction to eliminate errors in detected temperatures that may occur between the ASIC 11 and the MCU 12, the present embodiment utilizes the memory 21. A known storage device such as a DRAM may be used as the memory 21, and the memory 21 can also function as a work memory for the CPU 19 in normal mode and power saving mode. According to this embodiment, the same effects as those of the first embodiment can be obtained using a relatively inexpensive memory 21 and without using the nonvolatile memory 15. Furthermore, since the information required for the correction can be collectively managed in the memory 21, it can be said that the same functions as those of the first embodiment can be realized relatively simply.

[0041] 6 is a flowchart showing the control content according to this embodiment when the computing device 10 returns from the power saving mode to the normal mode. S501 to S504 are the same as S301 to S304 (see FIG. 4) in the first embodiment described above, respectively. S505 is the same as S306 in the first embodiment described above. That is, in this embodiment, the correction in S305 can be performed based only on the information stored in the memory 21, and there is no need to refer to the nonvolatile memory 15. Therefore, it is possible to perform the correction relatively quickly to eliminate the error in the detected temperature that may occur between the ASIC 11 and the MCU 12.

[0042] In the first and second embodiments, the correction for eliminating the error in the detected temperatures that may occur between the ASIC 11 and the MCU 12 is performed when returning from the power saving mode to the normal mode, but the timing is not limited to this example. For example, the correction may be performed when transitioning from the normal mode to the power saving mode, which can also eliminate the error that may occur between the operating modes.

[0043] (others) In the embodiments, individual elements are named based on their main functions, but the functions described in the embodiments may be sub-functions and are not strictly limited to these expressions. Furthermore, these expressions can be replaced with similar expressions. Similarly, the expression "unit" can be replaced with "tool," "component," "member," "structure," "assembly," etc. Alternatively, these terms may be omitted or added.

[0044] Some features described in the embodiments are as follows: [1] A computing device including a temperature detection unit and configured to calculate a detection result of the temperature detection unit, The power supply includes a first processing unit that performs arithmetic processing based on a first voltage and a second processing unit that performs arithmetic processing based on a second voltage, and includes, as operation modes, a first mode in which both the first voltage and the second voltage are supplied, and a second mode in which the supply of the first voltage is suppressed; The temperature detection unit includes a selector that outputs the detection result to the first processing unit in the first mode and outputs the detection result to the second processing unit in the second mode. A computing device characterized by: [2] The second voltage is smaller than the first voltage. The arithmetic device according to [1], [3] The first processing unit has a larger proportion of analog circuits than the second processing unit. The arithmetic device according to [1] or [2], [4] the first processing unit and the second processing unit are capable of communicating with each other; One of the first processing unit and the second processing unit corrects the detection result received by the one of the first processing unit and the second processing unit from the selector based on the detection result received by the other of the first processing unit and the second processing unit from the selector. The arithmetic device according to any one of [1] to [3], characterized in that: [5] further comprising an operation input unit that receives an operation input for switching between the first mode and the second mode; the first processing unit and the second processing unit are capable of communicating with each other; When the operation input unit receives an operation input for transitioning from the first mode to the second mode, the selector outputs a detection result to the second processing unit before the transition, and the first processing unit suppresses the transition when a difference between the detection result received by the first processing unit from the selector and the detection result received by the second processing unit from the selector is equal to or greater than a reference value. The arithmetic device according to any one of [1] to [4], characterized in that: [6] The device further includes a notification unit that outputs a predetermined notification when the difference is equal to or greater than the reference value. The arithmetic device according to [5], [7] The temperature detection unit includes a first resistive element receiving the first voltage, a second resistive element receiving the second voltage, and an electric element connected in series with both of them. The arithmetic device according to any one of [1] to [6], characterized in that: [8] The electrical element is a third resistive element. The arithmetic device according to [7], [9] The electric element is a rectifying element. The arithmetic device according to [7],

[10] The selector is disposed on an electrical path between the first resistive element and the second resistive element and the electrical element. The arithmetic device according to any one of [7] to [9], characterized in that:

[11] The arithmetic device according to any one of [1] to

[10] , a drive unit that performs drive control based on a calculation result of the detection result of the temperature detection unit; An electronic device characterized by:

[0045] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0046] 10: arithmetic unit, VDD1: voltage (first voltage), VDD2: voltage (second voltage), 11: main control unit (first processing unit), 12: sub-control unit (second processing unit), 14: temperature detection unit, 30: selector.

Claims

1. A computing device comprising a temperature detection unit, which calculates a detection result of the temperature detection unit, a first processing unit and a second processing unit that perform calculations on the detection results; The operation modes include a first mode and a second mode in which the power consumption of the arithmetic unit is smaller than that of the first mode, An electric element whose resistance value varies with temperature; a selector capable of selectively connecting a first electrical path connected to the first processing unit and a second electrical path connected to the second processing unit. A computing device characterized by:

2. The first processing unit is configured such that a voltage applied in the second mode is smaller than that applied in the first mode.

2. The computing device according to claim 1 .

3. The first processing unit is configured such that no voltage is applied to it in the second mode.

2. The computing device according to claim 1 .

4. The power consumed by the first processing unit is smaller in the second mode than in the first mode.

4. The computing device according to claim 1, wherein the first and second inputs are input to the first and second inputs.

5. The first processing unit operates based on a first voltage, the second processing unit operates based on a second voltage; The second voltage is less than the first voltage.

2. The computing device according to claim 1 .

6. The selector: connects to the first electrical path in the first mode; In the second mode, the second electrical path is connected.

2. The computing device according to claim 1 .

7. A storage means for storing the detected temperature, The second processing unit stores the temperature detected during the second mode in the storage means.

2. The computing device according to claim 1 .

8. The first processing unit is an integrated circuit.

2. The computing device according to claim 1 .

9. An inkjet printer equipped with a temperature detection unit and capable of ejecting ink, a first processing unit that performs calculation processing on the detection result of the temperature detection unit, and a second processing unit; The inkjet printer includes, as operation modes, a first mode and a second mode in which the power consumption of the inkjet printer is lower than that of the first mode; An electric element whose resistance value varies with temperature; a selector capable of selectively connecting a first electrical path connected to the first processing unit and a second electrical path connected to the second processing unit; a drive device that performs drive control based on a calculation result of the detection result of the temperature detection unit. An inkjet printer characterized by:

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