JP4545415B2 - Printer - Google Patents

Description

  The present invention generally relates to a printer, and more particularly to a label printer that performs printing on a label temporarily attached to a mount.

  Generally, a printer is connected to a host computer and used in an online state. When the printer in the online state receives data such as a command and print data transmitted from the host computer, it analyzes the command and print data in response to this and starts a printing operation.

  By the way, an 8-bit parallel interface manufactured by Centronics has been widely used as an interface for a printer to receive data transmitted from a host computer. However, in recent years, as an interface for transmitting data from the host computer to the printer as well as from the printer to the host computer, bidirectional Centronics (IEEE 1284 standard Bicentrics, hereinafter referred to as “IEEE1284 standard”) is used. Is becoming more popular. There are a plurality of modes in the IEEE 1284 standard, and one of them is an ECP (extended capabilities port) mode. In this ECP mode, 8-bit parallel data can be transmitted and received in both directions at high speed.

  In the IEEE 1284 standard, prior to transmission / reception of data such as commands and print data, a negotiation is performed between the host computer and the printer to determine communication settings such as communication speed while exchanging information with each other. Transition from mode to bidirectional mode.

  In the negotiation, first, the host computer sets the Selection signal to high level and the AutoFd signal to low level. Next, when the printer supports the bidirectional mode, the Select signal, the Fault signal, and the PE signal are set to the high level.

  After confirming these signals, the host computer sets the AutoFd signal to the high level. Next, after confirming these signals, the printer sets the Fault signal and the PE signal to a low level. In addition, when the extended link is supported, the printer notifies the host computer that the Select signal is set to high level, and when the extended link is not supported, the Select signal is set to low level. Further, the printer sets the Ack signal to high level and prepares for reception of commands and print data.

  However, the host computer may output an indefinite signal when the power is turned on and activated. If the printer is turned on before the host computer is turned on, the printer misidentifies the indefinite signal that is output when the host computer is turned on as a normally transmitted signal. As a result, the state transits to the negotiation state and enters a freeze state in order to wait for the next signal transmitted from the host computer. In order to cancel the freeze state, the printer power must be turned on again, which is very complicated.

As a related technology, the following Patent Document 1 provides a peripheral device termination control at the time of initialization of an information processing device, thereby surely initializing a peripheral device even when the peripheral device is in a bidirectional mode. An information processing apparatus that can be used is described. According to this information processing apparatus, in a peripheral device such as a printer that is frequently used, it is possible to avoid the initialization trouble of the peripheral device that can communicate with the IEEE 1284 standard by performing the negotiation before the peripheral device is initialized. However, this Patent Document 1 describes an initialization trouble caused by termination, but does not describe an initialization trouble caused by an indefinite signal transmitted when the host computer is activated. Further, although an information processing apparatus for avoiding initialization trouble is described, a printer for avoiding initialization trouble is not described.
JP-A-10-222252 (page 3, FIG. 3)

  Accordingly, in view of the above points, the present invention provides a printer that can negotiate with a host computer without the need to turn on the power again even when an indefinite signal is output when the host computer starts up. With the goal.

In order to solve the above problems, a label printer according to the present invention is connected to a host computer and used in an online state.
An interface that receives print data after negotiating with the host computer, a determination unit that determines whether or not the negotiation by the interface is completed, and the negotiation by the determination unit is not completed A reset unit that resets the interface after a predetermined period of time has elapsed since the start of negotiation, and a printing unit that performs a printing operation based on data transmitted from the host computer after the end of the negotiation. comprising, the reset means comprises a first pulse output circuit, NE-ST bar signal for outputting a first pulse signal longer activated than the time required to terminate normally from the start to negotiate NE-L bar in sync with the fall of The activated item, if the negotiation is determined not to be finished by the determination means, the activated when the first pulse signal output from the first pulse output circuit is deactivated And a second pulse output circuit that outputs a second pulse signal, wherein only the interface is reset based on a second pulse signal output from the second pulse output circuit. . The reset means also supplies a reset signal for resetting the interface to the determination means.

  According to the present invention, even when an indefinite signal is output when the host computer is started up, it is possible to negotiate with the host computer without having to turn on the power again.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing an internal structure of a printer according to an embodiment of the present invention. In the present embodiment, a thermal printer for printing on a label will be described as an example.
In the printer 10, a continuous label body 13 is used as a print medium. The label continuous body 13 is configured by temporarily attaching the label 11 to the mount 12 so as to be peelable. The label 11 is thermal paper and, for example, colors black at a predetermined temperature.

  As shown in FIG. 1, the continuous label body 13 is wound around a paper tube and attached to a rotatable supply shaft 14. When the stepping motor 16 drives the platen roller 15 via the belt 17, the label continuous body 13 is conveyed from right to left in the drawing. The conveyance of the continuous label body 13 is controlled based on the detection result of the sensor 19, and the thermal head 18 prints on the label 11 included in the continuous label body 13. Here, the operation of each unit is controlled by the control unit 20.

  FIG. 2 is a block diagram illustrating a configuration of a control unit that controls each unit of the printer according to the embodiment of the present invention. A ROM (read only memory) 21 of the control unit 20 stores in advance a control program for controlling each unit of the printer. On the other hand, various data such as print data and setting data are temporarily stored in a RAM (random access memory) 22. These data are supplied from the host computer 40 via the external interface 27 of the IEEE1284 standard. Each unit of the control unit 20 operates when power is supplied from the power supply unit 30.

  A CPU (central processing unit) 23 of the control unit 20 controls the motor control unit 24, the thermal head control unit 25, and the sensor control unit 26 in accordance with a control program stored in the ROM 21. Under the control of the CPU 23, the motor control unit 24 operates the stepping motor 16, the thermal head control unit 25 drives the thermal head 18 based on various data stored in the RAM 22, and the sensor control unit 26 Then, the sensor 19 is operated.

  In order to input data from the host computer 40 via the external interface 27, the external interface 27 negotiates with the host computer 40 after the printer 10 is powered on. In the present embodiment, in order to prevent the external interface 27 from being frozen due to an indefinite signal being output when the host computer 40 is activated, the control unit 20 is forced to reset the external interface 27. A reset unit 28 is provided.

  FIG. 3 is a diagram illustrating a configuration example of the forced reset unit in the printer according to the present embodiment. In the forced reset unit 28 shown in FIG. 3, the pulse output circuit 28a causes the falling edge of the NE-ST bar signal output from the CPU 23 when the CLR bar signal output from the CPU 23 is inactivated to a high level. In synchronization with the edge, the NE-L bar signal is activated to a low level for a certain period. The pulse output circuit 28b is synchronized with the rising edge of the NE-L bar signal input from the pulse output circuit 28a when the CLR bar signal output from the CPU 23 is inactivated to a high level. The NE-RES bar signal is activated to a low level for a certain period.

  The AND circuit 28c generates an INT bar (RES) signal based on the RESET bar signal that is at a high level when the printer 10 is powered on and the NE-RES bar signal output from the pulse output circuit 28b. Activate to low level. In the present embodiment, monostable multivibrators are used as the pulse output circuits 28a and 28b, and each output a pulse having a predetermined pulse width. For example, the pulse output circuit 28a outputs a pulse having a pulse width of 1 second.

  Next, the operation of each part of the printer in the negotiation will be described with reference to FIGS. FIG. 4 is a flowchart illustrating an operation in printer negotiation according to the present embodiment. FIG. 5 is a timing chart showing waveforms of signals in the printer negotiation according to the present embodiment. 5A is a timing chart when the negotiation is not completed within a predetermined period, and FIG. 5B is a timing when the negotiation is completed within the predetermined period. It is a chart.

  First, in step S1, the printer 10 is turned on to place the printer 10 in a standby state. Next, in step S2, the host computer 40 is powered on. The host computer 40 that is turned on outputs an indefinite signal at the time of startup. In particular, when a high-level Selection signal and a low-level AutoFd signal are output, the printer 10 shifts to a negotiation state.

  In step S3, when a high-level Selection signal and a low-level AutoFd signal are transmitted from the host computer 40, in step S4, the external interface 27 recognizes that it has transitioned to the negotiation state and is in negotiation. A negotiation flag indicating that is set in the status register.

  In step S5, the CPU 23 activates the NE-ST bar signal indicating the start of negotiation to a low level. In step S6, the pulse output circuit 28a activates the NE-L bar signal to low level for 1 second in synchronization with the falling edge of the NE-ST bar signal, and outputs a low level pulse. It should be noted that the period for activating the NE-L bar signal needs to be longer than at least the period necessary for performing the negotiation.

  In step S7, while the NE-L bar signal is activated to the low level, the CPU 23 detects the state of the negotiation flag in the state register of the external interface 27, so that the negotiation is completed within a predetermined period. It is determined whether or not. Here, when the negotiation is not completed within the predetermined period, the process proceeds to step S8, and when the negotiation is completed within the predetermined period, the process proceeds to step S11.

  If the negotiation has not been completed within the predetermined period, in step S8, the pulse output circuit 28b is synchronized with the rising edge of the NE-L bar signal as shown in FIG. -The RES bar signal is activated to a low level. Since one of the input terminals of the AND circuit 28c receives a RESET bar signal that has been deactivated to a high level when the power of the printer 10 is turned on, before the rise of the NE-L bar signal. In this state, the INT bar (RES) signal that has been deactivated to the high level is activated to the low level in synchronization with the rising edge of the NE-L bar signal. Since the activated INT bar (RES) signal is input to the reset terminal (negative logic) of the external interface 27, the external interface 27 is forcibly reset in step S9.

  Further, since the INT bar (RES) signal is also input to the interrupt port (negative logic) of the CPU 23, in step S10, the CPU 23 recognizes that the external interface 27 has been forcibly reset and negotiates again. The external interface 27 is controlled to perform.

  In this way, the pulse output circuit 28a activates the NE-L bar signal to a low level for a predetermined period in synchronization with the falling edge of the NE-ST bar signal, during which the CPU 23 determines whether or not the negotiation has ended. If the negotiation is not completed within a predetermined period, the external interface 27 can be forcibly reset.

  On the other hand, when the negotiation is completed within a predetermined period, in step S11, as shown in FIG. 5B, the CPU 23 activates the CLR bar signal to a low level. Therefore, the pulse output circuit 28b maintains the NE-RES bar signal at a high level. Since one of the input terminals of the AND circuit 28c receives a RESET bar signal that has been deactivated to a high level when the power of the printer 10 is turned on, before the rise of the NE-L bar signal. The INT bar (RES) signal that has been deactivated to the high level in this state is maintained at the high level. Therefore, the external interface 27 is not forcibly reset.

  According to the present embodiment, even when an indefinite signal is output when the host computer is started by turning on the printer 10 before turning on the host computer 40, the negotiation can be performed normally. Can do. When the negotiation is normally performed, data can be transmitted and received between the host computer 40 and the external interface 27, and various data such as print data and setting data are transmitted from the host computer 40 via the interface 27 to the CPU 23. And stored in the RAM 22 shown in FIG. Based on various data stored in the RAM 22, the CPU 23 controls each unit to print a label.

  The present invention can be used in a general printer or a label printer that performs printing on a label temporarily attached to a mount.

1 is a diagram illustrating an internal structure of a printer according to an embodiment of the present invention. FIG. 3 is a block diagram illustrating a configuration of a control unit that controls each unit of the printer according to the embodiment of the present invention. It is a figure which shows the structural example of the forced reset part in the printer which concerns on one Embodiment of this invention. 4 is a flowchart illustrating an operation in printer negotiation according to an embodiment of the present invention. 6 is a timing chart showing waveforms of signals in printer negotiation according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Printer 11 Label 12 Mount 13 Label continuous body 14 Supply shaft 15 Platen roller 16 Stepping motor 17 Belt 18 Thermal head 19 Sensor 20 Control part 21 ROM
22 RAM
23 CPU
24 motor control unit 25 thermal head control unit 26 sensor control unit 27 external interface 28 forced reset unit 30 power supply unit 40 host computer

Claims (2)

In a label printer connected to a host computer and used online,
An interface that receives print data after negotiating with the host computer, a determination unit that determines whether or not the negotiation by the interface is completed, and the negotiation by the determination unit is not completed A reset unit that resets the interface after a predetermined period of time has elapsed since the start of negotiation, and a printing unit that performs a printing operation based on data transmitted from the host computer after the end of the negotiation. comprising, the reset means comprises a first pulse output circuit, NE-ST bar signal for outputting a first pulse signal longer activated than the time required to terminate normally from the start to negotiate NE-L bar in sync with the fall of The activated item, if the negotiation is determined not to be finished by the determination means, the activated when the first pulse signal output from the first pulse output circuit is deactivated And a second pulse output circuit that outputs a second pulse signal, wherein only the interface is reset based on a second pulse signal output from the second pulse output circuit. Label printer. The label printer according to claim 1, wherein the reset unit also supplies a reset signal for resetting the interface to the determination unit.

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