JP3226043B2 - Input / output control method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to an input / output control method and apparatus for controlling an interface between an external device such as a host computer and an input / output device.

[Prior 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.

[Problems to be solved by the invention]

However, on the contrary, there is a case where it is desired that only a specific input / output device is connected to a certain external device, or that a certain input / output device is set to transfer data only with a specific external device. . However, in the above-mentioned conventional example, for example, a signal analysis device or the like is used to measure a communication procedure between an external device and an input / output device that are actually connected and operating, and for example, the communication procedure is performed by another external device. By imitating, the input / output device can be connected to any other external device, and data can be exchanged between the external device and the input / output device. Generally, some types of input / output devices, such as printers, require that image signals to be received from an external device be restricted, or more desirable. For example, in a color printer or the like that forms an image using toners of four colors of cyan, magenta, yellow, and black, an image signal for printing all colors at the highest density is given from an external device. When printing is performed based on the above, the life of each component of the printer may be shortened. Many of these restrictions are know-how,
In general, it is rarely 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 have been 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 provides an input / output control method and apparatus which select external devices that can be connected to an input / output device so that only external devices that comply with a certain standard can be connected. The purpose is to:

[Means for Solving the Problems]

In order to achieve the above object, an input / output control device of the present invention has the following configuration. That is, an input / output control device for confirming an interface specification between an external device including an image memory and an input / output device for reading or printing an image, wherein key information is transmitted from the input / output device to the external device. Transfer means for transferring, the receiving means for receiving response information transferred from the external device to the input / output device based on the key information, and a numerical value included in the response information received by the receiving means, Determining means for determining whether or not the numeric value calculated based on a predetermined formula based on the key information is determined, and according to a determination result by the determining means,
Control means for transferring image data between the external device and the input / output device and / or controlling a reading operation or a printing operation in the input / output device. In order to achieve the above object, an input / output control device of the present invention has the following configuration. That is, an input / output control device for confirming an interface specification between an external device including an image memory and an input / output device for reading or printing an image, wherein key information is transmitted from the input / output device to the external device. Transfer means for transferring the reply information, receiving means for receiving response information transferred from the external device to the input / output device based on the key information, and calculating means for calculating a plurality of pieces of response information based on the key information And means for changing data processing in the input / output device depending on which of the plurality of pieces of response information matches the response information. Further, the input / output control method of the present invention includes the following steps. That is, an input / output control method in an image processing apparatus that performs input / output of image data with an external device, wherein key information is transmitted to the external device, and the key information is obtained in the external device based on the key information. Receiving response information from the external device, determining whether the external device is valid according to the received response information, and controlling input / output of the image data according to the determination result. I do.

[Action]

In the above configuration, according to the input / output control device of the present invention, the key information is transferred from the input / output device to the external device, and the external device transmits the key information to the input / output device based on the key information. Receives the response information to be transferred, and determines whether a numerical value included in the received response information matches a numerical value calculated based on a predetermined calculation formula based on the key information. According to the result, the image data is transferred between the external device and the input / output device and / or the reading operation or the printing operation of the input / output device is controlled. According to the input / output control device of the third aspect, key information is transferred from the input / output device to the external device, and response information transferred from the external device to the input / output device is received based on the key information. Then, an operation is performed to change the data processing in the input / output device depending on which of the plurality of pieces of answer information calculated based on the key information matches. According to the input / output control method of the fifth aspect, the key information is transmitted to the external device, and the external device receives response information obtained based on the key information from the external device. It determines whether the external device is legitimate according to the response information, and operates to control the input and output of image data according to the determination result.

【Example】

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. <First Embodiment> FIG. 1 is a block diagram showing a schematic configuration of a color printer 2 of the present embodiment. The color printer 2 is connected to the external device 1 via communication lines 12 and 13. Then, at the time of printing execution, printing is executed by receiving an image signal via the image line 12. 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 any printer engine. For example, in this embodiment, it is assumed that the printer engine 10 is a printer unit of a color copying machine manufactured by Canon Inc. The image signal input from the external device 1 is a real-time image signal synchronized with the vertical synchronizing signal VSYNC and the horizontal synchronizing signal HSYNC, and the interface specification of the printer 2 is a so-called video interface specification. The CPU 4 controls each unit based on a control program stored in the program ROM 5. Reference numeral 41 denotes a timer built in the CPU 4, which generates a timer interrupt to the CPU 4 at predetermined time intervals according to an instruction from the CPU 4, as described later.
The RAM 6 temporarily stores various control data during the operation of the CPU 4, and is backed up in a non-volatile manner by a battery (not shown) or the like. 61 is the key (Ke
y) It is a key buffer (Key) that stores the code. Reference numeral 7 denotes a control I / O port, which is used by the CPU 4 to control solenoids, motors, and the like of each unit 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 is used. Since the communication procedure using RS232C is well known, its protocol and the like are not particularly described. <Explanation of Operation (FIGS. 2 to 4)> Next, with reference to flowcharts shown in FIGS. 2 to 4, the operation of the color printer 2 of the present embodiment and the communication between the color printer 2 and the external device 1 will be described. The interface control between them will be described. FIG. 2 is a flowchart showing the operation of the color printer 2 of the embodiment. The control program of the CPU 4 for executing this processing 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 to check whether a print start command has been sent from the external device 1. Note that the print start instruction is a code sent from the external device 1 here, but is not a start instruction based on a code or the like.
For example, the start of printing may be instructed by a voltage level or the like sent through a dedicated signal line. When the print start command is input, the process proceeds from step S2 to step S3, and based on the result of 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 valid device, the process returns to step S1 to check again whether the external device 1 is valid. In this 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 when it is determined in step S3 that the external device 1 is not a valid external device, the present invention is performed. The present invention 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 activated by an interrupt signal output from the timer 41 every 2 msec, for example. First, "1" is added to the variable Key61 of the RAM 6 in step S11. This variable Key61 is, for example, 4 bytes (Key [0], Key [1], K
ey [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 same as the value of the key when the power is turned off. However, when the power of the printer 2 is turned on, the value of the key 61 described above is updated every 2 msec.
Is a completely unpredictable random number. When the value of Key 61 is updated in this way, the process proceeds to step S12, where other processes associated with the timer interrupt are performed. FIG. 4 is a flowchart showing a process for checking whether the external device 1 shown in step S1 of FIG. 2 is valid. First, in step S31, the variable Key61 is copied to another variable Key2 (not shown) provided in the RAM 6. This is because there is a possibility that the value of Key61 is changed due to a timer interrupt during this processing. Next, proceeding to step S32, through the external communication circuit 3, K
The value of ey2 is transmitted to the external device 1. Next, the process proceeds to step S33, and a response (ANS1) corresponding to Key2 is received from the external device 1 through the external communication circuit 3. The response ANS1 is, for example, ANS1 [0], ANS1 [1], ANS1 each having 4 bytes.
Is a variable consisting of [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 values of ANS2 and ANS3 are also similar to ANS1 described above.
Each is a 4-byte variable. Here, for example, a calculation formula for calculating ANS2 is set as follows. (Expression 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, when the result of the calculation is 1 byte or more, 8 bits from the lower bit are adopted as each byte data. * Indicates multiplication, and XOR indicates exclusive OR. ANS3 is calculated using another formula. By incorporating these formulas into the valid external device 1, the response value (ANS1) from the valid external device 1 becomes the same value as at least one of the values ANS2 or ANS3 calculated by the color printer 2. Should be. 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 flow advances to step S36 to set "2" 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). If ANS1 and ANS3 do not match in step S35, the flow advances to step S37 to determine whether ANS1 and ANS2 match. If they match, the flow advances to step S38 to set "1" as a valid device variable. this is,
This means that the currently connected external device 1 is a legitimate device and its device level is “1” (described later). If the response ANS1 received from the external device 1 does not match any of ANS2 and ANS3 calculated in the color printer 2, 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 valid device. At this time, it is determined in step S3 in FIG. 2 that the external device 1 is not a valid external device. Also, when the transmission or reception in step S32 or step S33 fails, the device level of the currently connected external device 1 is set to "0". Next, the above-described 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. When printing is performed in step S4 in FIG. 2, for example, of the functions of the color printer 2 that can be realized, a function used to print the image data sent from the external device 1 is selected. It is used for changing the parameters of the image processing in the processing circuit 8. Here, as described above, a plurality of device levels such as “1” and “2” can be set because there are some restrictions in the color printer 2 and some levels in know-how. This is because the level of the external device 1 can be classified accordingly. For example, for an external device 1 capable of instructing printing by maximizing the function of the color printer 2, a calculation formula for calculating a response value ANS2 corresponding to the device level "1" is stored. Although there are some restrictions, the external device 2 that does not cause any problem even when connected to the color printer 2 incorporates a calculation formula for calculating the response value ANS3 corresponding to the device level “2”. Accordingly, 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 transmitted to the external device 1, and stops transmission / reception with the external device 1 if necessary. (When the device level is "0"), the image data processing in the color printer 2 is changed or the gradation control method is changed according to the device level of the external device 1 and received. The image signal can be printed, for example, without causing the maximum load of the printer. Accordingly, there is no problem such as printing in a state where an excessive load is applied to the color printer 2, and the life of the printer 2 due to the overload can be shortened and troubles can be reduced. <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 the so-called video interface system, which receives image data from the external device 1 in real time via the image line 12. In the second embodiment, communication with the external device 1 and reception of image data are all performed using the same general-purpose communication means 14. This communication means 14 is, for example, GPIB or SCSI (Small Computer System).
ms Interface). In this embodiment, the transfer of the variable Key2 from the color printer 20 to the external device 1 and the reception of the response value ANS1 from the external device 1 are performed via the communication means 14. At the time of executing the printing shown in FIG. 2, the image data is also taken in from the external device 1 via the communication means 14 and temporarily stored in the image memories 16-1 to 16-3. Thereafter, the printer engine 10 is transmitted via the image processing circuit 8 and the gradation control circuit 9.
To be 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, and it is necessary to temporarily store the received image data. is there. In the present 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. Another input / output device such as an input device or an image input device such as a scanner may be used. On the color printer side, instead of calculating the second response values ASN2 and ANS3 described above, for example, by calculating back from the response value ANS1 sent from the external device 1 based on the above-described equation 1, the original value is obtained. The device level of the external device 1 may be checked based on whether or not the key value is obtained. As described above, according to this embodiment, the key information is transferred to the external device, and the response value returned from the external device is inspected 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 does not understand the restriction 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.

【The invention's effect】

As described above, according to the present invention, an input / output device can be prevented from being connected to an unauthorized external device, so that the input / output device can be properly connected to an external device for use, and occurrence of a failure and the like can be reduced. There is an effect that can be done.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a color printer of a first embodiment, FIGS. 2 to 4 are flowcharts showing a control algorithm of the color printer of the embodiment, and FIG. 5 is a second embodiment. FIG. 2 is a block diagram illustrating a schematic configuration of an example color printer. In the figure, 1 ... external device, 2,20 ... color printer, 3 ...
... external communication circuit, 4 ... CPU, 5 ... ROM, 6 ... RAM,
7: control I / O port, 8: image processing circuit, 9: gradation control circuit, 10: printer engine, 12: image line, 13: communication line, 14: communication means, 16 .., Image memory, 41, timer, 61, variable Key.

Claims (6)

(57) [Claims] 1. An input / output control device for confirming an interface specification between an external device including an image memory and an input / output device for reading or printing an image. Transfer means for transferring key information by means of the key information; reception means for receiving response information transferred from the external device to the input / output device based on the key information; and transmission means included in the response information received by the reception means. Determining means for determining whether a numerical value matches a numerical value calculated based on a predetermined calculation formula based on the key information; and, in accordance with a determination result by the determining means, the external device and the input / output An input / output control device comprising: control means for transferring image data between the devices and / or controlling a reading operation or a printing operation in the input / output device. 2. The apparatus according to claim 1, wherein said control means prohibits transfer of input / output data or input / output operation between said external device and said input / output device when said determination means determines that they do not match. 2. The input / output control device according to 1. 3. An input / output control device for confirming an interface specification between an external device including an image memory and an input / output device for reading or printing an image. Transfer means for transferring key information by using the key information; receiving means for receiving response information transferred from the external device to the input / output device based on the key information; and calculating a plurality of pieces of response information based on the key information. An input / output control device, comprising: a calculating unit that performs data processing; and a unit that changes data processing in the input / output device depending on which of the plurality of pieces of response information matches the response information. 4. The input / output control device according to claim 1, wherein the key information is a random numerical value. 5. An input / output control method in an image processing apparatus for inputting / outputting image data to / from an external device, comprising: transmitting key information to the external device; Receiving the obtained response information from the external device, determining whether the external device is valid according to the received response information, and controlling input / output of the image data according to the determination result. An input / output control method characterized by the following. 6. The input / output control method according to claim 5, wherein said input / output control controls reception of image data from said external device in accordance with said determination result.