JPH0962410A - Image recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the interface signal line for power source state information of the image recording device simple and inexpensive. SOLUTION: The pull-up circuit of the I/F signal line of the I/F circuit of the device is constituted independently and current limiting circuits 104-12 and 104-13 are provided which supply signals to an interface output signal pull-up line and an interface input signal pull-up line with a power switch OFF. Further, the interface signal line P-h for power source state information which informs externally connected equipment of the ON/OFF state of the power switch means is connected to the output signal pull-up line of the current limiting circuit 104-12. When the power source is OFF, the I/F control circuit 104-1 performs control so that output drivers 104-2 and 104-3 connected to respective output signal lines output low-level signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus, and more particularly to an image recording apparatus for recording an image based on print data input from an external device on a recording medium.

[0002]

2. Description of the Related Art Normally, a power switch of an image recording apparatus main body is a switch of a power supply circuit. When the image recording apparatus power is on, power is supplied to a control circuit, and when the power is off, no power is supplied. However, when the power is turned off, a specific power-off sequence is performed for paper ejection and head protection, and in addition, a timer circuit is used for protection management when not in use. Instead of turning the power on / off on / off the power supply circuit, the control circuit is controlled so that printing is performed while the power is still being supplied and that printing is not performed (hereinafter, the state in which printing is not performed is called power off). There is an image recording device.

By the way, in the most general printer interface specification based on the Centro interface, a data bus and a strobe signal (STOROB) are provided between the data supply device and the image recording device section.
E: Latch signal of data output from the data supply device, hereinafter referred to as STB), acknowledge signal (ACKNO)
WLEDGE: A signal indicating that the recording device can receive the next data at “L” level, which will be referred to as ACK hereinafter, and a busy signal (B
USY: A signal indicating that data cannot be received at the “H” level, and is referred to as BUSY below. Error signal (ERROR: ”)
A signal indicating that the image recording device is in an error state at the L "level and hereinafter referred to as ERROR) and a large number of types of signals are connected. Using these signals, handshaking is performed between the respective devices, and accurate signals are obtained. Data can be received.

However, as described above, in the case of the image recording apparatus that controls the power on / off to the state in which the printing operation is performed or not performed, not the power supply circuit is turned on / off, the I / F signal is output even when the image recording apparatus is powered off. It is valid and the interface signal is no different from the normal offline state. Therefore, the data supply device connected to the outside cannot determine whether the state of the image recording device is the power-on state or the power-off state.

In order to grasp the state of the image recording apparatus, the data supply apparatus uses various control lines for the control which the signal line originally means, and also for the purpose of monitoring the power state of the image recording apparatus. In many cases.

Further, each interface signal line of the image recording apparatus is connected with a pull-up resistor for input protection, measures against delay time, use of an open collector circuit, and the like.

In view of this point, the electric power supplied to the interface circuit is separated into the input / output gate and the I / F signal control circuit and the pull-up portion of each input / output line, so that the image recording apparatus is powered on and off. , Means for limiting only the power supplied to the pull-up section of each input / output line,
There is also proposed a device that keeps supplying power to the I / F signal control circuit even when the power is off. With such a configuration, the power supply state of the image recording device can be more clearly transmitted to the data supply device while controlling each line.

However, when the data supply device tries to determine the power supply state of the image recording device by using these signals, these interface signals indicate that both the connected data supply device and the image recording device are in a normal state. The assumption is that the various signal lines do not operate as they are supposed to. Therefore, even if the detection is successful between the specific devices, it is not possible to guarantee the detection of the power state in the connection with an unspecified number of devices. In particular, since the state of the signal line is usually not defined when the power is off, an unintended state may occur in terms of circuitry, and as a result correct detection may not be possible.

[0009]

In recent years, the amount of information sent to an image recording apparatus tends to increase as the data processing apparatus becomes faster and more sophisticated. In addition, the amount of information sent from the data supply device to the image recording device also greatly increases due to the background that the image recording device itself can perform higher-definition recording operation, and the types thereof tend to diversify.

Therefore, the data supply device is required to grasp the type and resolution of the connected equipment, the state of the installed fonts, etc., and perform the most efficient data transfer. In order to meet these demands, as an extension function of the conventional parallel data transfer method, bidirectional I / F specified by IEEE1284 as an I / F specification that enables data transfer from an image recording device to a data supply device. F is known.

In such an I / F specification, when the data supply device grasps the state of the peripheral device, that is, the image recording device in this embodiment in more detail, first, the power source state is grasped and the I / F signal is detected. It is important to determine if it is correct.

Therefore, in addition to using the existing I / F signal, a dedicated signal for turning on / off the power of the image recording apparatus is separately prepared for the data supply apparatus, and the signal state is "H" level. At this time, the state of other signal lines is shown to be correct, and if it is at "L" level, the value indicated by the other signal is not shown to be correct, or the power of the image recording apparatus is turned off. There is an I / F specification.

However, in the case of newly providing a dedicated signal line for power source detection in such an I / F specification, it is necessary to control the signal line in synchronization with the power-on / off state of the image recording apparatus. There is a need for a new means for controlling the signal line and a driver as a means for actually changing the state of the signal line,
There is a problem that the control becomes complicated and the cost increases.

An object of the present invention is to provide a simple and inexpensive interface signal line for informing the power status in the I / F specification in which a dedicated signal for turning on / off the power of the image recording apparatus is separately prepared for the data supply apparatus. It is to be able to provide by the configuration.

[0015]

In order to solve the above problems, in the present invention, the means for limiting the power supplied to the pull-up circuit of each signal line of the interface circuit is divided into an input system and an output system, which are independent of each other. And a means for limiting the power supplied to the pull-up section of each input / output line when the power of the image recording apparatus is turned on and off, and informs the data supply apparatus of the power state of the image recording apparatus. The power supply status notification interface signal line is connected to the pull-up circuit of the output system through the current limiting resistor.

In such a structure, each line can be controlled by continuing to supply power to the I / F signal control circuit even when the power is off, and when the power of the image recording apparatus is off, each signal line pull-up circuit is connected. At the same time as limiting the power supply, at least one output signal, that is, "L" output is performed by the power supply status notification interface signal line.

When the image recording apparatus is in the power-on state, the power-state notification interface signal line is in the "H" level state to notify the data supply apparatus of the power-on state.

Further, when the image recording apparatus is in the power-off state, the power limiting means for the output signal pull-up circuit operates so that the interface signal line for power state notification is "
It becomes L ″ level, the image recording apparatus is in the power-off state, and notifies the data supply apparatus that the states indicated by the other I / F signal lines are not correct.

Further, at this time, the I / F signal control circuit which can be controlled even when the power of the image recording apparatus is off outputs the "L" level to the other output signal line, so that the data supply apparatus does not pass through the signal line. It is possible to suppress the level fluctuation of the signal line due to the power supplied intentionally and stably maintain the "L" level state.

As described above, it is possible to supply an effective power status notification interface signal to the data supply device without newly adding an output signal control means and a driver in terms of hardware or signal processing. It will be possible.

[0021]

1 shows an embodiment of an image recording apparatus of the present invention. FIG. 1 shows the interface circuit of the image recording apparatus of the present invention, and FIG. 2 shows the overall configuration of the image recording apparatus. In the figure, components with the same number are the same components.

In FIG. 2, reference numeral 1 is the main body of the image recording apparatus of the present embodiment, 2 is a data supply apparatus connected through an interface, and 101 is an MP that controls the processing of the entire apparatus.
A control circuit including U, a power supply circuit 102, a power switch (not shown), an operation panel including a power LED, 104 an interface circuit, 105 a print head drive circuit, 106 a motor drive circuit, 107 a print head, Reference numeral 108 denotes a paper feed motor for feeding a recording medium, and reference numeral 109 denotes a carriage motor for moving a carriage carrying a print head.

The power supply circuit 102 of the image recording apparatus is constantly supplied with power from the outside, and various voltages required for recording control, Vcc (for logic operation), Vm (for motor drive), and Vh (head). (For driving) is output.

Next, FIG. 1 shows the interface circuit 104.
FIG. 104-1 sets each signal line 104-9 to 104-10 to Hi according to the data from the control circuit 101.
A signal for controlling the gh level and the Low level is output to the drivers 104-2 to 104-3, and a signal input from the data supply device to the receiver 104-4 through the signal line 104-11 is supplied to the control circuit 101. I / Send to
It is an F signal control circuit.

The I / F control circuit 104-1 is supplied with the voltage Vcc from the power supply circuit 102 through the Vcc line 102-1.

The drivers 104-2 to 104-3 are open collector circuits, and the output "H" level is obtained by being connected to the pull-up line 102-2 by pull-up resistors 104-5 to 104-6. There is.

10 connected to Vcc line 102-1
4-12 and 104-13 are current limiting circuits and control circuit 1
Control signal 104-14 from 04-1 causes V
Switching from the cc line 102-1 to the subsequent stage is performed to limit the power supply to the pull-up lines 102-2 and 102-3 in synchronism with the on / off of the power source.

The signal line 104-16 (P-h) has a resistor 1
It is connected to the pull-up line 102-2 through 04-15. Therefore, in the above-described configuration, when the power of the image recording apparatus is on, the electric power is supplied to the high level from the Vcc line 102-1 through the current limiting circuit 104-12.

In the power-off state, the electric power supplied from the Vcc line 102-1 is the current limiting circuit 104-.
It is cut off by 12, and the pull-up line 102-2 becomes low level because no power is supplied.

Further, in the power-off state, the I / F control circuit 104-1 controls the output drivers 104-2 and 104-3 connected to the respective output signal lines to perform low level output, Resistance 104-5,
Pull-up line 102- connected through 104-6
It functions to stabilize 2 at a low level.

In this way, the 102-2 line which functions as a pull-up line when the power is on is pulled down through the driver circuits 104-2 and 104-3 when the power is off, and the resistor 104-15 is connected to the line 102-2. It is possible to stabilize the low level of the signal line P-h connected through.

The Vcc line 102-1 always supplies power. Further, the power supply circuit 102 continues to supply Vcc, Vm, Vh to other control circuits, motor drive circuits, head drive circuits, and the like.

The operation of this embodiment will be described below in order with reference to FIG.

First, in step S1, the power switch detection sequence is started. In step S2, it is confirmed whether or not the power switch has been pressed. The power switch (not shown) on the operation panel 103 may be a fixed on / off type, but in the present embodiment, as is apparent from the control of steps S2 and S3, when the switch is operated during power off, the power is turned off. It uses a circuit that turns on and turns off when the switch is operated during power on.

After confirming that the power switch has been operated in step S2, the state before the power switch is operated is determined in step S3. If it is in the power-on state before the power switch is operated, it means that the user has requested the power-off, so the process proceeds to step S4, and the Busy signal is activated so as not to accept the interface signal. To do.

Here, the Busy signal will be described as an example, but the same control is performed for at least one of the signals indicating that the image recording apparatus is not accepting data to the other data supply apparatus. It is also possible.

When the setting of the I / F signal is completed, the process proceeds to step S5 to turn off the display of the power LED (not shown) provided on the operation panel to show the user that the power is off. Further, in step S6, the print head 107 is moved to the cap position to perform capping for protection, and a series of operations called a power-off sequence such as discharging the paper in use is executed. When the power-off sequence process is completed, the I / F is set in step S7.
Current limiting circuit 104-12, 104-
By controlling 13, the signal is cut and the power off state of the signal line is created. As a result, as shown in step S8, the signal line 104-16 (P-h) connected to the pull-up line 102-2 through the resistor 104-15 becomes low level. In step S9, the process waits until the next power switch operation.

If the previous state is power off in step S3, or if the power switch is operated in step S9, the user requests power on, so the output I that is performing low output in step S10. / F signal 10
After setting 4-9 to 104-10 to the original output state, other I / F signals are also set to the power-on state in step S11. After that, in step S12, the pull-up resistors 1 of the I / F circuit 104, which are set to the energized state and cut off the current limiting circuits 104-12 and 104-13,
The Vcc supply to 04-5 to 104-7 is started, and the I / F signal is validated.

At this time, the Ph line of the signal line 104-16 becomes high. Further, in step S13, the power LED is turned on to indicate to the user that the power-on operation has been accepted. Next, in step S14, a series of operations called initial operations including a recovery operation of the print head and a paper feeding operation are executed. Then, step S15
The print standby state is entered.

According to the above configuration, since the signal line P-h is connected to the pull-up line of the current limiting circuit 104-12 for the output system, the signal line Ph can be eliminated without newly providing a dedicated switching circuit. P-h can be used as an interface signal line for notifying the power supply state of the image recording apparatus.

Although the current limiting circuits 104-12 and 104-13 are controlled simultaneously with each other in the present embodiment, they may be controlled independently, and if each is provided with a switching circuit, they are circuit-isolated and mutually isolated. Can be unaffected by.

[0042]

As is apparent from the above, according to the present invention, the I / F pull-up line, which is already controlled by the power status of the device, is used as the signal line when the interface signal line for power status notification is provided. As a result, it is not necessary to newly provide a signal switching circuit and a control signal, and a power supply status notification interface signal line can be realized with a simple and inexpensive configuration, and a hardware change from the conventional I / F specification is also facilitated. There is an excellent effect.

[Brief description of drawings]

FIG. 1 is a block diagram of an interface circuit of an image recording apparatus to which the present invention is applied.

FIG. 2 is a block diagram of the entire image recording apparatus to which the present invention is applied.

FIG. 3 is a flowchart showing an operation procedure to which the present invention is applied.

[Explanation of symbols]

 1 Image Recording Device Main Body 2 Data Supply Device 101 Control Circuit 102 Power Supply Circuit 102-1 Vcc Line 102-2 Pull-up Line 102 Power Supply Circuit 103 Operation Panel 104 I / F Circuit 104-1 I / F Control Circuit 104-12 Current limit circuit 104-13 Current limit circuit 104-15 Resistance 104-16 Signal line 104-2 to 104-3 Driver 104-4 Receiver 104-5 to 104-7 Pull-up resistance 104-9 to 104-10 Output I / F signal 105 print head drive circuit 106 motor drive circuit 107 print head 108 paper feed motor 109 carriage motor Ph signal line

Claims (2)

[Claims] 1. An image recording apparatus for recording an image based on print data inputted from the outside on a recording medium, wherein a power switch means and a power supply for supplying a predetermined power regardless of whether the power switch means is on or off. And a predetermined power is supplied from the power supply means regardless of whether the power switch means is on or off, and when the power switch means is in the on state, the received data is recorded, and the power switch means Control means for not recording the received data in the off state; and means for limiting the power supplied to the pull-up line of the interface input signal and the pull-up line of the interface output signal when the power switch means is in the off state. , The on / off state of the power switch means for devices connected to the outside There is at least one interface signal line for notifying the power supply state, the pull-up power limiting means is configured independently for an input signal and an output signal of the interface signal, An image recording device characterized by being connected to an output signal pull-up line. 2. When the power switch means is off, the power status notification interface signal is set to "L".
The image recording apparatus according to claim 1, wherein the image recording apparatus has a level.