JP3251574B2 - Input / output control method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an input / output control method and apparatus for determining a control function of an input / output device for processing an instruction from an external device.

[0002]

2. Description of the Related Art Conventionally, there are various connection methods for connecting a host computer (external device) and an input / output device. If the external device and the input / output device adopt the same method among such connection methods, by following the communication procedure, the input / output data can be exchanged between the external device and the input / output device. Transfer can be performed.

[0003]

However, on the contrary, only a specific input / output device should be connected to a certain external device, or a certain input / output device can transfer data only to / from a specific external device. You may want to set it not to do so.

[0004] However, in the above-mentioned conventional example, it is actually connected and operated by, for example, a signal analyzer.
Measure the communication procedure between an external device and an input / output device,
For example, by imitating the communication procedure with another external device, connecting the input / output device to any other external device and exchanging data between the external device and the input / output device Can be.

In general, some types of input / output devices, such as printers, require that an image signal to be received from an external device be limited, or more preferable. For example, cyan, magenta, yellow,
In a color printer or the like that forms an image using four black toners, an image signal that prints all colors at the highest density is given from an external device, and printing is performed based on the data. The life of each part of the printer may be shortened.

[0006] Such restrictions are often of the know-how and are generally not disclosed to the outside. For this reason, if the above-mentioned color printer or the like is connected to an external device that does not have such a restriction function, data for recording an image at the maximum density by the color printer is always input, or an unnecessary load is imposed on the printer. A situation such as wearing occurs. As a result, there are problems such as shortening of the life of the printer and failure of the printer.

The present invention has been made in view of the above conventional example, and determines the device level of an external device connectable to an input / output device, and processes the instruction from the external device in accordance with the device level. It is an object of the present invention to provide an input / output control device and a method for changing a control function of an output device.

[0008]

To achieve the above object, an input / output control method according to the present invention comprises the following steps. That is, an input / output control method for determining a control function of an input / output device that processes an instruction from an external device, wherein the device level of the external device is set from a plurality of device levels by communicating with the external device, The control function of the input / output device for processing an instruction from the external device is changed according to the set device level.

To achieve the above object, the input / output control device of the present invention has the following configuration. That is, an input / output control device that determines a control function of an input / output device that processes an instruction from an external device, and that sets the device level of the external device from a plurality of device levels by communicating with the external device. Setting means, and control function changing means for changing a control function of the input / output device for processing an instruction from the external device according to a device level set by the level setting device. .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

<Embodiment 1> FIG. 1 shows Embodiment 1 of the present invention.
1 is a block diagram showing a schematic configuration of a color printer 2 of FIG.

The color printer 2 has a communication line 1
2 and 13 are connected to the external device 1. Then, when printing is performed, an image signal is received via the image line 12 and printing is performed. At this time, the image signal input from the external device 1 is sent to the printer engine 10 via the image processing circuit 8 and the gradation control circuit 9. The printer engine 10 may be anything, but for example, in this embodiment, it is assumed that the printer engine is a printer unit of a color copying machine manufactured by Canon Inc.

The image signal input from the external device 1 is
This is a real-time image signal synchronized with the vertical synchronization signal VSYNC and the horizontal synchronization signal HSYNC.
Is a so-called video interface specification.

The CPU 4 controls each section based on a control program stored in the program ROM 5. 41 is a timer built in the CPU 4,
As described later in accordance with the instruction of No. 4, the CPU
4 generates a timer interrupt. RAM6 is CPU4
During the operation of, various data for control are temporarily stored, and are backed up in a nonvolatile manner by a battery (not shown) or the like. Reference numeral 61 denotes a key buffer (Key) that stores a key (Key) code described later.

Reference numeral 7 denotes a control I / O port which is used by the CPU 4 to control solenoids, motors and the like of various parts of the printer engine 10. An external communication circuit 3 controls a communication procedure when the CPU 4 communicates with the external device 1. In this embodiment, the communication procedure controlled by the communication circuit 3 is, for example, an RS232C communication procedure. Since a communication procedure using RS232C is well known, its protocol and the like are not particularly described.

<Description of Operation (FIGS. 2 to 4)> Next, FIGS.
The operation of the color printer 2 and the interface control between the color printer 2 and the external device 1 according to the present embodiment will be described with reference to the flowchart shown in FIG.

FIG. 2 shows a color printer 2 according to this embodiment.
The control program of the CPU 4 for executing this process is stored in the ROM 5.

In FIG. 2, when the power of the color printer 2 is first turned on, the process proceeds to step S1, where the specifications of the external device 1 are checked to determine whether or not the connected external device is valid. This will be described later in detail with reference to the flowchart of FIG.

Next, the process proceeds to step S2, where it is checked whether a print start command has been sent from the external device 1. Although the print start command is a code sent from the external device 1 here, the print start command is not a start command based on a code or the like. For example, the print start command may be given by a voltage level or the like sent through a dedicated signal line. Good. When a print start command is input, the process proceeds from step S2 to step S.
3 and based on the determination made in step S1,
If it is a valid external device, printing is performed in step S4.

On the other hand, if the connected external device 1 is not a legitimate device, the process returns to step S1, and again the external device 1
Find out if is legitimate. In the present embodiment, the check of the external device 1 in step S1 is performed when the power is turned on and when a print start command is received and it is determined in step S3 that the external device 1 is not a valid external device. Is not limited to this, and may be executed, for example, irregularly.

FIG. 3 is a flowchart showing timer interrupt processing by the timer 41 in the color printer 2.

This timer interrupt is, for example, 2 msec.
It is started by an interrupt signal output from the timer 41 every time. First, in step S11, the variable Key6
"1" is added to "1". This variable Key61 is, for example, 4 bytes (Key [0], Key [1], Key
[2], Key [3]: Key [i] indicates the i-th byte).

Since the timer interrupt is executed only when the power of the color printer 2 is turned on, the key value immediately after the power of the color printer 2 is turned on is the K value at the time of turning off the power.
It is the same as the value of ey. However, when the power of the printer 2 is turned on, the value of the above-mentioned Key 61 is updated every 2 msec, so that the value of the Key 61 is a random number that cannot be predicted at all. When the value of Key 61 is updated in this way, the process proceeds to step S12, and other processes associated with the timer interrupt are performed.

FIG. 4 is a flowchart showing a process for checking whether or not the external device 1 shown in step S1 of FIG. 2 is valid.

First, at step S31, the variable Key61
To another variable Key2 (not shown) provided in the RAM 6.
Copy to This is because the value of Key 61 may be changed due to a timer interrupt during this process.

Next, in step S 32, the value of Key 2 is transmitted to the external device 1 through the external communication circuit 3. Next, the process proceeds to step S33, through the external communication circuit 3,
A response (ANS1) corresponding to Key2 is received from the external device 1. The response ANS1 is, for example, ANS1 [0], ANS1 [1], ANS1 each having 4 bytes.
[2] and ANS1 [3] (where,
[I] indicates the i-th byte).

Next, the process proceeds to step S34, where ANS2 and ANS3 are calculated from Key2 in the color printer 2 based on a predetermined calculation formula. These ANS2, AN
The value of S3 is also a 4-byte variable similarly to ANS1 described above.

Here, for example, a calculation formula for calculating ANS2 is set as follows. (Equation 1) ANS2 [0] = Key [0] + Key [1] + Key [2] + Key [3] ANS2 [1] = Key [0] * Key [1] / Key [2] ANS2 [2] = ( Key [0] +20) * Key [3] ANS2 [3] = Key [0] XOR Key [1] XOR Key [2] XOR Key [3] However, if these calculation results are more than 1 byte, It is assumed that 8 bits from the lower bits are adopted as each byte data. * Indicates multiplication, and XOR indicates exclusive OR.

ANS3 is calculated using another formula. By incorporating these calculation formulas into the legitimate external device 1, the response value (A
NS1) is the value ANS calculated by the color printer 2.
2, or at least one of ANS3.

Thus, the process proceeds to step S35, and it is determined whether or not the response ANS1 received from the external device 1 matches ANS3. If they match, the process proceeds to step S36, where "2" is set as a valid device variable. This means that the currently connected external device 1 is a legitimate device and its device level is “2” (described later).

In step S35, ANS1 and ANS are
When 3 does not match, the process proceeds to step S37, where ANS
It is determined whether 1 and ANS2 match. If they match, the process proceeds to step S38, where "1" is set as a valid device variable. This means that the currently connected external device 1 is a legitimate device, and its device level is “1” (described later).

The response ANS1 received from the external device 1 is
ANS2 and ANS3 calculated in the color printer 2
If it does not match any of the above, the process proceeds to step S39, and the device level is set to “0”. This means that the external device 1 currently connected to the printer 2 is not a legitimate device.
In 3 it is determined that the device is not a valid external device.

Step S32 or step S33
Also, when transmission or reception fails in the above, the device level of the currently connected external device 1 is set to “0”.

Next, the above-mentioned device level will be described. This device level is used in step S3 of the flowchart of FIG. 2 to determine whether the connected external device 1 is valid. Further, when printing is performed in step S4 of FIG. 2, for example, of the functions of the color printer 2 that can be realized, a function used to print image data sent from the external device 1 is selected, and image processing is performed. It is used for changing parameters of image processing in the circuit 8 and the like.

Here, as described above, a plurality of device levels such as "1" and "2" can be set because there are some restrictions specific to the color printer 2 and some know-how. This is because there is a level and the level of the external device 1 can be classified according to the level. For example, for an external device 1 capable of instructing printing by maximizing the functions of the color printer 2, a calculation formula for calculating a response value ANS2 corresponding to the device level "1" is stored. In addition, although there are some restrictions, the external device 2 that is not particularly problematic even when connected to the color printer 2 incorporates a calculation formula for calculating the response value ANS3 corresponding to the device level “2”.

Thus, the color printer 2 determines the device level of the connected external device 1 based on the response value to the value of the key sent to the external device 1, and transmits / receives data to / from the external device 1 if necessary. It stops (when the device level is “0”), changes the processing of image data in the color printer 2 in accordance with the device level of the external device 1,
By changing the method of gradation control, the received image signal can be printed so as not to become the maximum load of the printer, for example.

Therefore, there is no problem such as printing in the state where an excessive load is applied in the color printer 2, and it is possible to shorten the life of the printer 2 due to the overload and to reduce troubles.

<Second Embodiment (FIG. 5)> FIG. 5 is a block diagram showing a schematic configuration of a color printer 20 according to a second embodiment.

In the above-described first embodiment, the color printer 2 receives image data (print data) by a so-called video interface system, which receives image data in real time from the external device 1 via the image line 12. However, in the second embodiment, communication with the external device 1 and reception of image data are all performed by the same general-purpose communication unit 14.
This is performed using The communication means 14 is a general-purpose communication protocol such as GPIB or SCSI (Small Computer Systems Interface).

In the second embodiment, the transfer of the variable Key 2 from the color printer 20 to the external device 1 and the reception of the response value ANS 1 from the external device 1 are performed by the communication unit 1.
4 is performed. At the time of execution of the printing in FIG. 2, the image data is also fetched from the external device 1 via the communication means 14 and temporarily stored in the image memories 16-1 to 16-.
3 Thereafter, the image data is sent to the printer engine 10 via the image processing circuit 8 and the gradation control circuit 9 and printed.

The image memory 16 is provided because the data printing speed of the printer engine 10 is generally slower than the transfer speed of the general-purpose communication means 14. Therefore, it is necessary to temporarily store the received image data. Because there is.

In this embodiment, the case where the input / output device is a color printer has been described. However, the present invention is not limited to this, and may be, for example, a monochrome printer. For example, another input / output device such as a display, a coordinate input device, or an image input device such as a scanner may be used.

On the color printer side, instead of calculating the above-mentioned second response values ANS2 and ANS3,
For example, from the response value ANS1 sent from the external device 1, the original K
The device level of the external device 1 may be checked based on whether the ey value is obtained.

The present invention is not limited to only the apparatus and method for realizing the above-described embodiment, but is intended to realize the above-described embodiment in a computer (CPU or MPU) in the above-mentioned system or apparatus. The present invention also includes a case where the above-described embodiment is realized by supplying the software program code of the above and the computer of the system or apparatus operates the various devices according to the program code.

In this case, the program code of the software implements the functions of the above-described embodiment, and the program code itself and means for supplying the program code to the computer, specifically, A storage medium storing the above program code is included in the scope of the present invention.

As a storage medium for storing such a program code, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, C
D-ROM, magnetic tape, nonvolatile memory card, R
OM or the like can be used.

In addition to the case where the computer controls the various devices in accordance with only the supplied program code to realize the functions of the above-described embodiment, the program code operates on the computer. Such a program code is also included in the scope of the present invention when the above-described embodiment is realized in cooperation with an OS (Operating System) or other application software.

Further, after the supplied program code is stored in a memory provided in a function expansion board of a computer or a function expansion unit connected to the computer, the function expansion board or function is stored based on an instruction of the program code. The case where the CPU or the like provided in the storage unit performs part or all of the actual processing, and the above-described embodiment is realized by the processing is also included in the scope of the present invention.

As described above, according to the present embodiment, the key information is transferred to the external device, and the response value returned from the external device is checked based on the key information. Then, only when the response value is appropriate, the image signal from the connected external device is received and processed, thereby preventing the connection with the external device which is not aware of the restrictions specific to the printer. be able to.

As a result, it is possible to prevent a failure of the printer or a reduction in the life of parts, which may occur when the printer is connected to an external device whose restrictions are not understood.

[0051]

As described above, according to the present invention, the control function of the input / output device for processing an instruction from the external device is changed depending on the device level of the external device. There is an effect that it can be used properly depending on the device level of the external device.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a color printer according to a first embodiment.

FIG. 2 is a flowchart illustrating an operation of the color printer according to the embodiment.

FIG. 3 illustrates a color printer according to the present embodiment.
9 is a flowchart illustrating a timer interrupt process by a timer.

FIG. 4 is a flowchart illustrating a process for checking whether or not an external device in the color printer according to the present embodiment is legitimate;

FIG. 5 is a block diagram illustrating a schematic configuration of a color printer according to a second embodiment of the present invention.

Claims (10)

(57) [Claims] 1. An input / output control method for determining a control function of an input / output device that processes an instruction from an external device, wherein the device level of the external device is reduced from a plurality of device levels by communicating with the external device. An input / output control method, comprising: setting and changing a control function of the input / output device that processes an instruction from the external device according to the set device level. 2. The plurality of device levels include at least a level at which a maximum control function of the input / output device can be executed, a level at which a control function including restrictions can be executed, and a control function of the input / output device. 2. The input / output control method according to claim 1, wherein the input / output control method includes a level that is not to be performed. 3. The device level of the external device is set from a plurality of device levels by performing bidirectional communication for transmitting information to the external device and acquiring a processing result thereof. 3. The input / output control method according to 1 or 2. 4. The apparatus according to claim 1, wherein the input / output device has a color print function, and changes an image processing parameter according to the set device level. The input / output control method described in 1. 5. The input / output control method according to claim 1, wherein a reading operation or a printing operation in the input / output device is controlled according to the set device level. . 6. An input / output control device that determines a control function of an input / output device that processes an instruction from an external device, wherein the device level of the external device is reduced from a plurality of device levels by communicating with the external device. Level setting means for setting, and control function changing means for changing a control function of the input / output device that processes an instruction from the external device according to a device level set by the level setting device. Characteristic input / output control device. 7. The plurality of device levels are at least a level at which a maximum control function of the input / output device can be executed, a level at which a control function including restrictions can be executed, and a control function of the input / output device. 7. The input / output control device according to claim 6, wherein the input / output control device includes a level that is not to be performed. 8. The level setting means sets a device level of the external device from a plurality of device levels by performing bidirectional communication for transmitting information to the external device and acquiring a processing result thereof. The input / output control device according to claim 6 or 7, wherein: 9. The input / output device has a color print function, and the control function changing means changes image processing parameters for the input / output device according to the set device level. The input / output control device according to any one of claims 6 to 8, wherein: 10. The apparatus according to claim 6, wherein the control function changing unit controls a reading operation or a printing operation in the input / output device according to the set device level. 2. The input / output control device according to item 1.