JP2004351899A - Electronic equipment - Google Patents

Abstract

An object of the present invention is to provide an appropriate power supply according to a power load state at the time of operation of a functional block, minimize a load on a power supply means inside a device such as a built-in battery, and reduce consumption of a built-in battery as an operation power supply. I do.
A printing apparatus has a power supply (battery power supply) supplied from a battery via a voltage conversion circuit, and a power supply (USB power supply) supplied from a host device via a power supply line of a USB cable. ). When printing is performed using the thermal head 20, the power load is determined from the number of printing dots before the operation, and the power using a battery power supply or a USB power supply is switched via the switching circuit 59 according to the power load state. It is selectively supplied to a functional block including the head 20 and the head driver 54. As a result, appropriate power supply according to the power load state at that time can be performed, and the consumption of the battery 57 can be prevented.
[Selection diagram] FIG.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electronic device including a power supply unit inside the device and operating by receiving power supply from a host device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an electronic device disclosed in Patent Document 1 is known as an electronic device that includes a power supply unit inside the device and operates by receiving power supply from a host device.
[0003]
The electronic device is connected to a computer device via a USB cable and has a mouse function as a pointing device of the computer device, and print data corresponding to a character string designated on the display screen by the mouse function. The printer has a printer function of receiving from a printer and printing it on recording paper. For this reason, a mouse unit having a mouse function and a printer unit having a printer function are housed inside the main body of the electronic device, and a built-in battery for supplying drive power to the mouse unit and the printer unit is housed.
[0004]
In this electronic device, both the functional blocks of the mouse unit and the printer unit are driven by power supplied from a built-in battery, but operate in response to operating power supplied from a higher-level device via a USB cable. It is also configured.
[0005]
[Patent Document 1]
JP 2002-41504 A
[0006]
[Problems to be solved by the invention]
In the conventional electronic device, a functional block in the electronic device is operated by either a battery power supply built in the device or power supply from a higher-level device. Although a power capacity for driving a functional block having a large load, such as a printer unit, can be ensured, there is a problem that battery consumption is large. On the other hand, if the power of the functional block is received from a higher-level device via a USB cable, the consumption of the built-in battery can be prevented. However, since the power that can be supplied via USB is limited, the power load state of the printer unit is limited. In some cases, it may not be possible to receive the power required for operation.
[0007]
The present invention solves such a problem, and has at least one or more functional blocks, includes a power supply unit inside the device, and a higher-level device via a connection cable including a data communication line and a power supply line. In an electronic device that receives power supply from the device, it is possible to supply appropriate power according to the power load state during operation of the function block, and to provide a power supply means inside the device such as a built-in battery that supplies power to the function block. It is an object of the present invention to provide an electronic device configured to minimize the burden and to reduce the consumption of a built-in battery as an operation power supply.
[0008]
[Means for Solving the Problems]
An electronic device according to the present invention has at least one or more functional blocks, includes a power supply unit inside, and receives power supply from a higher-level device via a connection cable including a data communication line and a power supply line. For a specific functional block among the functional blocks, a load state confirming means for confirming a power load state at the time of operation based on an operating condition before the operation of the specific functional block, based on a confirmation result of the load state confirming means. Determining means for determining whether the specific function block can be driven by using the power supplied from the higher-level device, and determining that the specific function block can be driven by the determination means, The power supplied from the higher-level device is supplied via a connection cable, and when it is determined that the power supply cannot be driven, the power supply means is supplied to the specific functional block. And a controlling means for supplying electric power from.
[0009]
According to the electronic device configured as described above, the power load state at the time of operation of a specific function block is confirmed before operation, and based on the confirmation result, the power supplied to the function block is received from the host device, Alternatively, since the power is supplied from the internal power supply means, power can be supplied from a power supply that matches the power load state at the time of operation of the functional block, and the functional block can be operated without difficulty using the supplied power. Further, when the power load state of the functional block can be driven by the power received from the higher-level device, the power is not used to receive the power supply from the internal power supply means. Can be reduced, and the consumption of a built-in battery used as an internal power supply can be reduced.
[0010]
Further, in the electronic device, a specific functional block whose power load state is to be checked has a power load state that fluctuates according to an operation condition during operation.
[0011]
Further, in the electronic device, when a specific functional block cannot be driven by power supplied from a higher-level device, two power sources can be effectively used by using power received from a higher-level device in addition to power supply means. The operation of the functional block can be performed by utilizing the function block.
[0012]
Further, in the electronic device, the specific functional block is a printing device that performs printing by selectively driving a plurality of heating elements provided in the print head, and the load state confirmation unit transfers the print condition to the print head. The apparatus may further include a counting unit that counts the number of dots related to printing of the print data, and the determination unit may include a comparison unit that compares a count value of the counting unit with a reference value.
[0013]
Further, in the electronic device, the specific functional block includes a print head in which a plurality of heating elements are selectively driven based on print data, and a print head that supplies the heating elements in accordance with a temperature of the print head during printing. A print control unit that controls an amount of power to be applied, wherein the load state checking unit includes a temperature detection unit that detects a temperature of the print head during printing, and the determination unit includes the temperature detection unit. And comparing means for comparing the detected value with the reference value.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
(1st Embodiment)
FIG. 1 is an external view showing the overall configuration of a printing system including a printing device as an electronic device of the present invention.
[0016]
The printing system includes a printing device 1 and a personal computer (higher-level device) 2 that controls the printing device 1. The personal computer 2 and the printing device 1 use a USB (Universal Serial Bus) cable 3. Connected via.
[0017]
The operation of each unit of the printing apparatus 1 is driven by an internal battery (not shown) or power supplied from the personal computer 2 via the USB cable 3.
[0018]
The apparatus main body 1a of the printing apparatus 1 has a built-in thermal transfer type printing mechanism, and prints a label printing surface of an optical disk 4 such as a CD-R created and edited by a personal computer 2 and supplied via a USB cable 3. For printing data, a tray 5 for mounting and supporting the optical disk 4 is provided on the apparatus main body 1a.
[0019]
The tray 5 protrudes forward from a predetermined position in the apparatus main body 1a and moves to a position outside the apparatus where the optical disk 4 can be attached and detached in response to operation of an eject button 6 provided on the front surface of the apparatus main body 1a. It has become.
[0020]
The personal computer 2 includes a keyboard 2a and a mouse 2b and has a display device 2c. The personal computer 2 prints a music title, an artist, and the like on the label printing surface of the optical disk 4 by the printing device 1. When the data creation / editing process is performed and the printing start designation process is performed, the printing data is transmitted to the printing device 1 connected to the interface, and the printing process is performed.
[0021]
FIG. 2 is a plan view showing a configuration of a tray driving mechanism and a printing mechanism of the printing apparatus 1, and FIG. 3 is a front view showing a configuration of the printing mechanism.
[0022]
Between the rear part of the apparatus main body 1 a and the rear part of the tray 5, there are provided coil springs 7, which constitute a mechanism for pushing out the tray 5. In addition, a locking mechanism 8 for locking the tray 5 so as to be detachable is provided at a rear portion of the apparatus main body 1a. The locking mechanism 8 includes a solenoid 9 and a locking hook 11 that rotates about a pin 10 in conjunction with a plunger of the solenoid 9. The locking hook 11 is formed at the rear of the tray 5. It is adapted to engage with the projection 13 in a detachable manner.
[0023]
When the tray 5 is pushed into the apparatus main body 1a and is located at a predetermined storage position, the coil spring 7 is compressed, and the projection 13 of the tray 5 engages with the locking hook 11 to move the tray 5 to the apparatus. It is held in the main body 1a.
[0024]
By operating the eject button 6 provided on the front surface of the apparatus main body 1a, the solenoid 9 is excited, its plunger is sucked, and the locking hook 11 is rotated about the pin 10 and the projection 13 of the tray 5 The tray 5 is disengaged and disengaged, and in response to the disengagement, the tray 5 is pushed out to the front side of the apparatus main body 1a by the elastic force of the coil spring 7.
[0025]
On the other hand, a printing mechanism as a printing unit is provided at a position above the tray 5 in the apparatus main body 1a. That is, a printer frame 14 is attached across the tray 5, and the printer frame 14 has a carriage guide 15 laid parallel to a lower side of a frame horizontal beam facing away from the upper surface of the tray 5. Is provided with a rack 16 extending along its longitudinal direction. A carriage 17 is provided movably along the carriage guide 15.
[0026]
The carriage 17 is provided with a traveling drive mechanism for the carriage 17, a head moving mechanism for the thermal head 20, and a winding mechanism for the ink ribbon 19, and a forward / reverse rotatable step motor 21 serving as a drive source for these mechanisms. Is attached to the back of the carriage 17.
[0027]
FIG. 4 is a view showing a configuration of a carriage traveling drive mechanism, a head moving mechanism, and an ink ribbon winding mechanism provided on the carriage 17 in the printing apparatus.
[0028]
A ribbon cartridge 18 is mounted on the carriage 17, and a ribbon feeding core 22 and a ribbon winding core 23 are provided in the ribbon cartridge 18, and an ink is supplied between the ribbon feeding core 22 and the ribbon winding core 23. An ink ribbon 19 as a member is stretched.
[0029]
A step motor 21 is disposed in the carriage 17, and an output gear 25 of the step motor 21 meshes with a drive gear 27 that meshes with the rack 16 via a two-stage gear 26. Further, the driving gear 27 is fitted to the ribbon winding core 23 and meshes with a one-way clutch gear 29 provided coaxially with a ribbon winding driving shaft 28 for driving the core.
[0030]
A cam gear 31 is provided in the carriage 17, and the cam gear 31 has an arc-shaped cam groove 32 eccentric with respect to the center of rotation. A swing clutch 33 is provided between the cam gear 31 and the output gear 25.
[0031]
The swinging clutch 33 includes a sun gear 34 meshed with the output gear 25 and a pair of planetary gears 35 meshed with the sun gear 34 and supported via an arm so as to be movable in the circumferential direction of the sun gear 34. When the sun gear 34 rotates clockwise, one planetary gear 35 meshes with the cam gear 31 and the other planetary gear 36 separates from the cam gear 31. When the sun gear 34 rotates counterclockwise, one planetary gear 36 rotates. The gear 35 separates from the cam gear 31 and the other planetary gear 36 meshes with the cam gear 31.
[0032]
A head arm 38 is provided in the carriage 17 and pivots up and down about a shaft 37. The head arm 38 is turned in a counterclockwise direction in FIG. The head arm 38 is provided with a pin 40 near one end thereof. The pin 40 is slidably inserted into the cam groove 32 of the cam gear 31. The thermal head 20 is attached to the other end of the head arm 38.
[0033]
FIG. 4 shows a state in which the head arm 38 is inclined at a predetermined angle and the thermal head 20 is at a printing position in which the thermal head 20 is down. The head arm 38 is substantially horizontal when engaged at a position A in the outermost peripheral direction of the head arm 32.
[0034]
In the printing apparatus configured as described above, the state where the carriage 17 is located at the home position at the left end of the printer frame 14 in FIG. 2 is in the non-printing position where the thermal head 20 is raised, and in this state, the step motor 21 rotates forward. When driven to start a printing operation, the cam gear 31 rotates clockwise via the output gear 25, the sun gear 34, and the planetary gear 35, and the thermal head 20 moves down to the printing position. During this time, the drive gear 27 meshing with the rack 16 is also driven, so that the carriage 17 moves to a printing start position slightly to the right of the home position in FIG.
[0035]
Then, while the thermal head 20 is driven based on the print data, the stepping motor 21 is continuously driven in the forward direction in synchronism therewith, whereby the thermal head 20 moves together with the carriage 17 along the carriage guide 15. Then, printing is performed in a predetermined printing range H (FIG. 2) on the label printing surface on the optical disk 4 within the moving range of the thermal head 20.
[0036]
A notch (not shown) is formed in a part of the periphery of the cam gear 31. When the cam gear 31 rotates by a certain angle in response to the forward rotation of the step motor 21, the notch is formed in the notch. Since the planetary gear 35 falls and idles, the head arm 38 is configured to maintain its tilt angle and maintain the thermal head 20 at the printing position. When the carriage 17 moves, the thermal head 20 is maintained at the printing position.
[0037]
During this time, as the carriage 17 moves to the right, the ribbon winding drive shaft 28 is driven via the output gear 25, the second gear 26, the drive gear 27 and the one-way clutch gear 29 to use the used ink ribbon. 19 is wound around the ribbon winding core 23.
[0038]
When the carriage 17 moves to the right end in FIG. 2 and printing is completed, the step motor 21 is driven in the reverse direction, and the cam gear 31 rotates counterclockwise through the output gear 25, the sun gear 34, and the planetary gear 36, and The head 20 moves up to a non-printing position where the head 20 is separated from the optical disc 4. During this time, the drive gear 27 meshing with the rack 16 is also driven, so that the carriage 17 moves leftward from the right end in FIG.
[0039]
A notch (not shown) is formed at a part of the periphery of the cam gear 31 corresponding to the planetary gear 36, and the cam gear 31 rotates by a predetermined angle to return the thermal head 20 to the print standby position. The planetary gear 36 falls into the missing portion when the vehicle rotates, and idles.
[0040]
After the planetary gear 36 is located in the missing portion, the carriage 17 moves toward the left home position while the thermal head 20 is held at the non-printing position by the driving of the driving gear 27 by the reverse rotation of the step motor 21. , Return to the home position and end the operation.
[0041]
FIG. 5 is a block diagram illustrating a configuration of an electronic circuit of the printing device 1 according to the first embodiment.
[0042]
The printing apparatus 1 includes a CPU 51, which is connected to the personal computer 2 shown in FIG. Print data created and edited by the personal computer 2 is supplied via a data communication line 3D of the USB cable 3, and power is supplied via a power supply line 3P of the USB cable 3.
[0043]
The CPU 51 includes a ROM 52 and a RAM 53. The ROM 52 includes, in addition to a system program for controlling the operation of each unit of the printing apparatus 1 according to a print control signal from the personal computer 2, a control for realizing power supply switching control according to a power load state during operation. Various program data including programs and the like are stored. The RAM 53 includes a print buffer 53a for storing print data transmitted from the personal computer 2, and a reference value (first and second reference values) of the number of print dots preset as a determination condition at the time of power supply switching. And a reference temperature storage unit 53c storing a head temperature reference value used in a second embodiment described later.
[0044]
The reference value of the number of print dots stored in the reference dot number storage unit 53b is, for example, the first number of print dots when one third of all the heat generating resistance elements of the thermal head 20 are driven to generate heat. The second reference value is a reference value, and the number of print dots when two thirds of all the heating resistance elements are driven to generate heat.
[0045]
The CPU 51 is connected to the thermal head 20 via a head driver 54, the step motor 21 via a motor driver 55, and the solenoid 9 via a solenoid drive transistor Tr. The CPU 51 outputs a motor control signal to the motor driver 54 in accordance with the print control signal transmitted from the personal computer 2 to drive the step motor 21, and outputs a head control signal to the head driver 55 to control the thermal head 20. Drive.
[0046]
A plurality of heating elements are arranged in a line in the thermal head 20, and printing is performed by driving these heating elements to generate heat. The thermal head 20 is provided with a temperature sensor 56 for detecting a temperature during printing, and a temperature detection signal is input to the CPU 51. The temperature sensor 56 is used in a second embodiment described later.
[0047]
Here, the printing apparatus 1 includes a power supply (hereinafter, referred to as a battery power supply) supplied from a battery 57 via a voltage conversion circuit 58, and a power supply line of a USB cable 3 from a personal computer 2 as a host device. And a power supply (hereinafter, referred to as a USB power supply) supplied via the 3P.
[0048]
When such two power supplies are provided, the battery power supply has a problem in that the power consumption for driving a functional block having a large power load can be secured, but the battery consumption is large. On the other hand, if the USB power supply is used, the battery consumption can be reduced. However, since the power that can be supplied via the USB cable 3 is limited, the power required for operation cannot be supplied depending on the power load state. is there.
[0049]
Therefore, in the printing apparatus 1, a function block in which the power load state fluctuates according to the operating condition at the time of operation among the function blocks is set as a specific function block, and the battery is connected to the battery according to the power load state of the function block. By selectively using a power supply or the USB power supply to supply power, power required for operation is secured and battery consumption is minimized.
[0050]
The functional blocks are, specifically, the CPU 51, the solenoid 9, the thermal head 20, the head driver 54, the step motor 21, the motor driver 55, and the like. Hereinafter, among these, the printing unit including the thermal head 20 and the head driver 54 will be described as a specific functional block.
[0051]
Reference numeral 59 in the figure denotes a switching circuit for switching power supply to the specific functional block (the thermal head 20 and the head driver 54). The switching circuit 59 includes a contact a connected to the power supply line 3P of the USB cable 3, a contact b connected to the output line of the voltage conversion circuit 58, and a contact c connected to both lines. , A switch piece 59 a connected to the thermal head 20 and the head driver 54.
[0052]
The switching circuit 59 is controlled by the CPU 51 to switch between a USB power supply when the switch piece 59a is switched to the contact a, a battery power when the switch b is switched to the contact b, and a USB power supply when the switch c is switched to the contact c. Both powers of the battery power supply are supplied to the specific functional block. D1 and D2 in the figure are diodes for preventing backflow, which regulates the power of the USB power supply from entering the battery power supply system when the switch piece 59a of the switching circuit 59 is at the contact c, and also controls the battery power supply. Is regulated so as not to enter the USB power supply system.
[0053]
As for other functional blocks, for example, a USB power supply is used for the CPU 51. A battery power supply is used for driving the solenoid 9 and for driving the step motor 21 and the motor driver 55.
[0054]
Next, the operation of the first embodiment will be described.
[0055]
FIG. 6 is a flowchart illustrating a flow of a printing process including power supply switching control of the printing apparatus 1 according to the first embodiment. Each process shown in this flowchart is executed by the CPU 51 reading a program stored in the ROM 52.
[0056]
In a state where the printing apparatus 1 and the personal computer 2 are connected by the USB cable 3, print data is transferred from the personal computer 2 to the printing apparatus 1 via the data communication line 3D of the USB cable 3. The print data at this time is received by the CPU 51 provided in the printing apparatus 1, and is held in the print buffer 53a provided in a predetermined area of the RAM 53 (step A11).
[0057]
As described with reference to FIGS. 2 to 4, in the initial state, the carriage 17 is located at the home position on the left end of the printer frame 14 in FIG. It is in the print position. In this state, first, the stepping motor 21 is driven to rotate forward until the thermal head 20 is lowered to the printing position (steps A12 to A14), and then the print buffer 53a corresponds to the arrangement direction of each heating element of the thermal head 20. The print data for one line is read out (step A15).
[0058]
The step motor 21 is driven by a battery power supply. That is, electric power required for operation is supplied from the battery 57 to the step motor 21 and the motor driver 55 via the voltage conversion circuit 58.
[0059]
When one line of print data is read from the print buffer 53a, the number of dots when each heating element of the thermal head 20 is driven to generate heat is counted in accordance with the one line of print data (step A16). . Then, the counted value is compared with the first and second reference values previously stored in the reference dot number storage section 53b of the RAM 53 (step A17).
[0060]
According to the comparison result, if the counted value of the number of dots obtained from the print data for one line is equal to or less than the first reference value, that is, if the number of printed dots is equal to or less than one third of all the heating elements, It is determined that the power load on the head 20 is small and the thermal head 20 can be driven by the power from the USB power supply, and power is supplied to the thermal head 20 using the USB power supply (step A18). Specifically, a switching signal to the contact a is output from the CPU 51 to the switching circuit 59, and power is supplied from the personal computer 2 to the thermal head 20 and the head driver 54 via the power supply line 3P of the USB cable 3.
[0061]
On the other hand, the counted value of the number of dots obtained from the print data for one line is between the first and second reference values, that is, the number of printed dots exceeds one-third of all the heating elements and is one-third. If it is less than 2, it is determined that the thermal head 20 cannot be driven with the power from the USB power supply, and power is supplied to the thermal head 20 using the battery power (step A19). Specifically, a switching signal to the contact b is output from the CPU 51 to the switching circuit 59, and power is supplied from the internal battery 57 to the thermal head 20 and the head driver 54 via the voltage conversion circuit 58.
[0062]
If the counted value of the number of dots obtained from the print data for one line is equal to or larger than the second reference value, that is, if the number of printed dots is equal to or larger than two-thirds of all the heating elements, the USB is similarly used. It is determined that the thermal head 20 cannot be driven by the power from the power supply. In this case, considering that the power load is large and the battery power source alone consumes a large amount of the internal battery 57, a USB power source is used in addition to the battery power source (step A20). Specifically, the CPU 51 outputs a switching signal to the contact c to the switching circuit 59. As a result, in addition to the power supplied from the built-in battery 57, the power supplied from the personal computer 2 via the power supply line 3P of the USB cable 3 is supplied to the thermal head 20 and the head driver 54. Become.
[0063]
Then, the print data for one line is transferred to the thermal head 20 (step A21), and the respective heating elements of the thermal head 20 are driven to generate heat based on the print data, whereby the label of the optical disc 4 to be printed is driven. One line is printed on the printing surface (step A22).
[0064]
Further, while the thermal head 20 is being driven, the step motor 21 is driven to rotate forward in synchronism therewith (step A23). Thereby, the thermal head 20 moves along the carriage guide 15 integrally with the carriage 17. If unprocessed print data remains in the print buffer 53a (No in step A24), the print data is read out line by line in the same manner as described above, and printing is continued. Also in this case, before the printing operation based on each print data, the number of dots to be printed is counted, the power load state is determined from the comparison result of the counted value and the reference value, and the USB load is determined according to the power load state at that time. Power is supplied to the thermal head 20 using a power supply, a battery power supply, or both power supplies.
[0065]
When printing of all the lines is completed (Yes in step A24), the forward rotation drive of the step motor 21 is controlled to stop, and the movement of the carriage 17 is stopped (step A25). Subsequently, the step motor 21 is driven to rotate in the reverse direction (step A26). The reverse drive of the step motor 21 raises the thermal head 20 to the non-printing position, and moves the carriage 17 in a direction opposite to the printing direction. Then, when the carriage 17 returns to the initial position, that is, the home position at the left end shown in FIG. 2 (Yes in step A27), the reverse rotation drive of the step motor 21 is controlled to stop (step A28), and a series of printing is performed here. The process ends.
[0066]
As described above, by selectively using the battery power supply or the USB power supply according to the power load state of the thermal head 20 during the printing operation, the power necessary for the operation at that time is secured and the normal printing operation is performed. The operation time can be extended by minimizing battery consumption.
[0067]
(Second embodiment)
Next, a second embodiment of the present invention will be described.
[0068]
In the first embodiment, the power load state is determined from the number of dots to be printed before the printing operation. In the second embodiment, the power load state is determined from the temperature of the thermal head 20. A battery power supply or a USB power supply is selectively used depending on the power load state at that time.
[0069]
Note that FIG. 5 is used for the circuit configuration as the second embodiment. The configuration is different from the first embodiment in that a temperature sensor 56 is provided on the thermal head 20 and the temperature detection signal is input to the CPU 51. This means that a predetermined reference value of the head temperature is stored in the section 53c.
[0070]
FIG. 7 is a flowchart illustrating a flow of a printing process including power supply switching control of the printing apparatus 1 according to the second embodiment. Each process shown in this flowchart is executed by the CPU 51 reading a program stored in the ROM 52.
[0071]
With the printer 1 and the personal computer 2 connected by the USB cable 3, print data is transferred from the personal computer 2 to the printer 1 via the data communication line 3D of the USB cable 3, and the print data is printed. The data is received by the apparatus 1 and stored in the print buffer 53a of the RAM 53 (step B11). Then, the stepping motor 21 is driven to rotate forward until the thermal head 20 moves down to the printing position (steps B12 to B14).
[0072]
Here, the temperature of the thermal head 20 is detected by the temperature sensor 56 (step B15), and the detected temperature is compared with a reference temperature previously stored in the reference temperature storage unit 53c of the RAM 53 (step B16).
[0073]
As a result, when the temperature of the thermal head 20 exceeds the reference temperature (Yes in step B16), power is supplied to the thermal head 20 using a USB power supply (step B17). This is because when the thermal head 20 is in a state where the heat is stored above the reference temperature, the energy required to raise each of the heating elements of the thermal head 20 to the temperature required for print formation can be reduced. Has a relatively small power load. In the case of such a light load, a switching signal to the contact a is output from the CPU 51 to the switching circuit 59, and the thermal head 20 and the head driver 54 are transmitted from the personal computer 2 via the power supply line 3P of the USB cable 3. Is supplied with power.
[0074]
On the other hand, when the temperature of the thermal head 20 detected by the temperature sensor 56 does not exceed the reference temperature or is equal to or lower than the reference temperature (No in step B16), the power is supplied to the thermal head 20 using the battery power supply. It is supplied (step B18). This is because when the thermal head 20 is in a state of being cooled to a reference temperature or lower, a large amount of energy is required to raise each heating element of the thermal head 20 to a temperature required for print formation. The power load will be large. In such a case, the power may be insufficient with the USB power supply, so that the power supply is switched to the battery power supply. That is, a switching signal to the contact b is output from the CPU 51 to the switching circuit 59, and power is supplied from the internal battery 57 to the thermal head 20 and the head driver 54 via the voltage conversion circuit 58.
[0075]
Subsequent operations are the same as steps A21 to A28 in FIG.
[0076]
That is, the print data for one line is transferred to the thermal head 20, and the respective heating elements of the thermal head 20 are driven to generate heat based on the print data, so that the label print surface of the optical disc 4 to be printed is printed. The printing for one line is performed (step B19, step B20).
[0077]
Further, the stepping motor 21 is driven to rotate forward while the thermal head 20 is being driven, and the thermal head 20 moves together with the carriage 17, and during that time, the printing operation for the unprocessed print data is repeatedly performed in the same manner as described above (step B21). , Step B22). Also in this case, the temperature of the thermal head 20 is detected before the printing operation based on each print data, and the power load state is determined from the comparison result between the detected temperature and the reference temperature, and the USB load is determined according to the power load state at that time. A power supply or a battery power supply is selectively used to supply power to the thermal head 20.
[0078]
When printing for all lines is completed, the forward rotation drive of the step motor 21 is controlled to stop, and the movement of the carriage 17 stops (step B23). Subsequently, the step motor 21 is driven to rotate in the reverse direction (step B24). As a result, the thermal head 20 moves up to the non-printing position, and the carriage 17 moves in the direction opposite to the printing direction. Then, when the carriage 17 returns to the initial position, that is, the home position at the left end shown in FIG. 2, the reverse rotation drive of the step motor 21 is controlled to be stopped (step B25, step B26), and a series of printing processing here ends. I do.
[0079]
In this manner, by detecting the temperature of the thermal head 20 and determining the power load state, it is necessary to perform the operation using the optimal power supply according to the power load state at that time, as in the first embodiment. As a result, normal printing operation can be performed while securing sufficient power, and the operation time can be extended by minimizing battery consumption.
[0080]
(Third embodiment)
Next, a third embodiment will be described.
[0081]
In the first or second embodiment, the battery power and the USB power are switched according to the power load state of the thermal head 20 during the printing operation. However, in the third embodiment, the drive of the step motor 21 is further performed. Switching between battery power and USB power is performed for each operation that requires.
[0082]
FIG. 8 is a block diagram illustrating a configuration of an electronic circuit of the printing apparatus 1 according to the third embodiment. The same components as those in FIG. 5 (first embodiment) are denoted by the same reference numerals. .
[0083]
The first embodiment is structurally different from the first embodiment in that the stepping motor 21 and the motor driver 55 are used as specific functional blocks in addition to the thermal head 20 and the head driver 54, and the switching circuit 60 for the specific functional block is used. Is provided.
[0084]
The switching circuit 60 includes a contact d connected to the power supply line 3P of the USB cable 3, a contact e connected to the output line of the voltage conversion circuit 58, and a contact f connected to both lines. , A switch piece 60 a connected to the step motor 21 and the motor driver 55.
[0085]
The switching circuit 60 is switched and controlled by the CPU 51 together with the switching circuit 59, and is switched to a USB power supply when the switch piece 60a is switched to the contact d, a battery power supply when the switch piece 60 is switched to the contact e, and to a contact f. Then, both the USB power and the battery power are supplied to specific functional blocks including the step motor 21 and the motor driver 55. D3 and D4 in the figure are diodes for preventing backflow, which regulates the power of the USB power supply from entering the battery power supply system when the switch piece 60a of the switching circuit 60 is at the contact point f, as well as the battery power supply. Is regulated so as not to enter the USB power supply system.
[0086]
FIGS. 9 and 10 are flowcharts showing a flow of a printing process including power supply switching control of the printing apparatus 1 according to the third embodiment. Each process shown in this flowchart is executed by the CPU 51 reading a program stored in the ROM 52.
[0087]
Before describing the flowcharts of FIGS. 9 and 10, a power supply switching method according to the third embodiment will be briefly described for easy understanding.
[0088]
As described above, the third embodiment is characterized in that switching between battery power and USB power is performed, including power supply to the step motor 21. Here, focusing on the driving of the step motor 21, the driving timings are (a) a head down operation, (b) a printing operation, (c) a head up operation, and (d) a carriage return operation, The power load differs depending on each operating condition.
[0089]
That is, in the head down operation of (a) and the head up operation of (c), only the thermal head 20 is moved up and down at that position, and since the operation time is short, the power load is the smallest. Therefore, in that case, a USB power supply can be used.
[0090]
On the other hand, in the carriage return operation of (d), since a force for moving the carriage 17 toward the home position is required, the power load becomes larger than in the head down / up operation. Therefore, in this case, the power is insufficient with the USB power supply, and the power is supplied by switching to the battery power supply.
[0091]
In the printing operation (b), it is necessary to move the carriage 17 in synchronization with the printing operation of the thermal head 20 performed by pressing against the optical disk, and since the operation time is long, the power load becomes the largest. . Therefore, in that case, a battery power supply and a USB power supply are used together. At this time, the thermal head 20 has three stages (USB power supply / battery power supply / battery power supply and USB power supply) according to the power load state based on the number of print dots as described in the first embodiment. Perform switching.
[0092]
The printing process according to the third embodiment will be described below with reference to FIGS. 9 and 10 for each of these operations.
[0093]
(A) During head down operation
With the printer 1 and the personal computer 2 connected by the USB cable 3, print data is transferred from the personal computer 2 to the printer 1 via the data communication line 3D of the USB cable 3, and the print data is printed. The data is received by the device 1 and stored in the print buffer 53a of the RAM 53 (step C11).
[0094]
Here, first, power is supplied to the step motor 21 in order to lower the thermal head 20 to the printing position (step C12). In this case, since the power load of the step motor 21 during the head-down operation is the smallest as described above, power is supplied using a USB power supply at that time. More specifically, a switching signal to the contact d is output from the CPU 51 to the switching circuit 60, and power is supplied from the personal computer 2 to the step motor 21 and the motor driver 55 via the power supply line 3P of the USB cable 3.
[0095]
When power is supplied to the step motor 21, the step motor 21 is driven to rotate forward until the thermal head 20 is lowered to the printing position (steps C13 to C15).
[0096]
(B) During printing operation
Next, one line of print data is read from the print buffer 53a (step C16). Here, as in the first embodiment, the number of dots when each heating element of the thermal head 20 is driven to generate heat is counted in accordance with the print data for one line (step C17), and the counted value is stored in the RAM 53 in advance. Are compared with the first and second reference values stored in the reference dot number storage unit 53b (step C18).
[0097]
If the counted value of the number of dots obtained from the print data for one line is equal to or less than the first reference value according to the comparison result, power is supplied to the thermal head 20 using the USB power supply ( Step C19). If the counted value of the number of dots obtained from the print data for one line is between the first and second reference values, power is supplied to the thermal head 20 using a battery power supply (step S1). C20). If the counted value of the number of dots obtained from the print data for one line is equal to or more than the second reference value, USB power is used in addition to battery power (step C21).
[0098]
On the other hand, since the power load of the step motor 21 is the largest during the printing operation as described above, the power is supplied using both the battery power supply and the USB power supply (step C22). Specifically, a switching signal to the contact f is output from the CPU 51 to the switching circuit 60. As a result, in addition to the power supplied from the built-in battery 57, the power supplied from the personal computer 2 via the power supply line 3P of the USB cable 3 is supplied to the step motor 21 and the motor driver 55. Become.
[0099]
Then, the print data for one line is transferred to the thermal head 20 (step C23), and each heating element of the thermal head 20 is driven to generate heat based on the print data, so that the label of the optical disc 4 to be printed is driven. One line of printing is performed on the printing surface (step C24).
[0100]
Further, while the thermal head 20 is being driven, the step motor 21 is driven to rotate forward in synchronism therewith (step C25). Thereby, the thermal head 20 moves along the carriage guide 15 integrally with the carriage 17. If unprocessed print data remains in the print buffer 53a (No in step C26), the print data is read out in units of one line and printing is continued as described above.
[0101]
When the printing for all the lines is completed (Yes in step C26), the normal rotation drive of the step motor 21 is controlled to stop, and the movement of the carriage 17 is stopped (step C27).
[0102]
(C) Head-up operation
Next, power is supplied to the step motor 21 in order to raise the thermal head 20 to the non-printing position after printing is completed (step C28). In this case, the power load of the step motor 21 is the smallest during the head-up operation as in the head-down operation, as described above, so that power is supplied using the USB power supply. Then, with this power supply, the step motor 21 is driven to rotate in the reverse direction, and the thermal head 20 is raised to the non-print position (step C29). When the thermal head 20 moves up to the non-printing position (Yes in step C30), the reverse drive of the step motor 21 is controlled to stop (step C31).
[0103]
(D) During carriage return operation
Subsequently, power is supplied to the step motor 21 in order to return the carriage 17 to the initial position, that is, the home position at the left end shown in FIG. 2 (step C32). In this case, as described above, a load is applied more during the carriage return operation than when the head is down / up, and at that time, power is supplied using a battery power supply. Specifically, a switching signal to the contact e is output from the CPU 51 to the switching circuit 60, and power is supplied from the internal battery 57 to the step motor 21 and the motor driver 55 via the voltage conversion circuit 58.
[0104]
When the carriage 17 arrives at the initial position (Step C34: Yes), the reverse drive of the step motor 21 is stopped and controlled (Step C35). Is completed.
[0105]
In this way, by switching between the battery power supply and the USB power supply in accordance with the power load state at that time not only during the printing operation but also for each operation requiring driving of the step motor 21, power can be supplied more efficiently. And the battery life can be further extended.
[0106]
In the third embodiment, it is assumed that the thermal head 20 during the printing operation is switched in three stages (USB power supply / battery power supply / battery power supply and USB power supply) according to the power load state based on the number of print dots. As described above, by detecting the temperature of the thermal head 20 as in the second embodiment, two-stage (USB power / battery power) switching is performed according to the power load state determined from the head temperature. That is fine.
[0107]
In short, the present invention is not limited to the above-described embodiment, and can be variously modified in an implementation stage without departing from the gist thereof.
[0108]
【The invention's effect】
As described in detail above, according to the present invention, power can be supplied from a power supply that matches the power load state during operation of a functional block, and the functional block can be operated without difficulty by the supplied power. When the power load state of the functional block can be driven by the power received from the higher-level device, the load on the internal power supply can be reduced by using the power from the higher-level device. Consumption of a built-in battery used as a battery can be reduced.
[Brief description of the drawings]
FIG. 1 is an external view showing the overall configuration of a printing system including a printing device as an electronic device of the present invention.
FIG. 2 is a plan view illustrating a configuration of a tray driving mechanism and a printing mechanism of the printing apparatus.
FIG. 3 is a front view illustrating a configuration of a printing mechanism of the printing apparatus.
FIG. 4 is a diagram illustrating a configuration of a carriage in the printing apparatus.
FIG. 5 is a block diagram illustrating a configuration of an electronic circuit of the printing apparatus according to the first embodiment of the present invention.
FIG. 6 is a flowchart illustrating a flow of a printing process including power supply switching control of the printing apparatus according to the first embodiment of the present invention.
FIG. 7 is a flowchart illustrating a flow of a printing process including power supply switching control of a printing apparatus according to a second embodiment of the present invention.
FIG. 8 is a block diagram illustrating a configuration of an electronic circuit of a printing apparatus according to a third embodiment of the present invention.
FIG. 9 is a flowchart illustrating a flow of a printing process including power supply switching control of a printing apparatus according to a third embodiment of the present invention.
FIG. 10 is a flowchart illustrating a flow of a printing process including power supply switching control of a printing apparatus according to a third embodiment of the present invention.
[Explanation of symbols]
1 ... printing device
1a: Device body
2. Personal computer
3 ... USB cable
3D ... data communication line
3P ... power supply line
4… Optical disk
5… Tray
9 ... solenoid
17… Carriage
18… Ink ribbon cassette
19 ... Ink ribbon
20… Thermal head
21… Carriage motor
38… Head arm
51 ... CPU
52… ROM
53… RAM
54… Head driver
55… Motor driver
56 ... temperature sensor
57… Built-in battery
58 ... voltage conversion circuit
59 ... Switching circuit
59a ... Switch piece
60: Switching circuit
60a ... Switch piece
Tr: Solenoid drive transistor
D1 to D4: Diode

Claims (5)

An electronic device having at least one or more functional blocks, including a power supply unit inside the device, and receiving power supply from a higher-level device via a connection cable including a data communication line and a power supply line,
For a specific functional block in the functional block, before the operation, load state checking means for checking the power load state at the time of operation based on operating conditions,
Determining means for determining whether the specific functional block can be driven using power supplied from the higher-level device based on a result of the confirmation by the load state confirming means;
When the determination of the determination means is drivable, the power received from the higher-level device is supplied to the specific functional block via the connection cable, and when the drive is not possible, the specific functional block is supplied to the specific functional block. Control means for supplying power from the power supply means;
An electronic device comprising: The device has two or more functional blocks,
The said load state confirmation means performs a process with respect to the function block whose electric power load state fluctuates according to the operating conditions at the time of operation among the said plurality of function blocks as said specific function block. 2. The electronic device according to 1. The device has two or more functional blocks,
The control unit supplies the power received from the higher-level device via the connection cable to the specific functional block, in addition to the power supply unit, when it is determined that the drive unit cannot be driven by the determination unit. The electronic device according to claim 1, wherein: The specific functional block is a printing device that performs printing by selectively driving a plurality of printing elements provided in a print head,
The load state checking unit includes a counting unit that counts the number of dots related to printing of print data to be transferred to the print head,
4. The electronic device according to claim 1, wherein the determination unit includes a comparison unit that compares a count value of the counting unit with a reference value. 5. The specific functional block includes: a print head in which a plurality of heating elements are selectively driven based on print data; and a print control that controls an amount of power supplied to the heating elements in accordance with a temperature of the print head during printing. And a control device.
The load state checking unit includes a temperature detecting unit that detects a temperature of the print head during printing,
4. The electronic device according to claim 1, wherein the determination unit includes a comparison unit configured to compare a detection value of the temperature detection unit with a reference value. 5.

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