JPH0738750A - Image processing system - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent abnormal operation due to lack of PSYNC and superposition of noise. The image processing apparatus synchronizes with the PSYNC signals 10, 12, 14 and 16 from the digital color copying machine to the image processing apparatus, and the image processing apparatus supplies an error detection code in the Bi signal of each color supplied to the digital color copying machine. Provide a frame for use. The error detection code frame consists of 8 bits, the first 3 bits C0 to C2 are the identification code of each frame, and the remaining 5 bits C3 to C7 are the number of PSYNC signals from the digital color copying machine. Is a count value indicating whether the signal is a Bi signal with respect to.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing system including a digital color copying machine, an image processing apparatus and a host computer.

[0002]

2. Description of the Related Art In an image processing system comprising a digital color copying machine, an image processing apparatus and a host computer, the interface between the digital color copying machine and the image processing apparatus is as shown in FIG. That is, PSYNC is a start signal for requesting color data of four colors from the digital color copying machine to the image processing apparatus. In order for the digital color copying machine to output one image, the image processing apparatus outputs the C plane. For M plane, Y
In synchronism with PSYNC for plane and K plane,
It is necessary to send the data of each color to a digital color copying machine.

The image processing apparatus first issues a "START" command in order to inform the digital color copying machine that the image data is to be sent. "START"
The digital color copier that received the command is
The YNC signal is transmitted to the image processing apparatus in the order of M, C, Y and K.

Further, in the digital color copying machine, the PSYNC signal emitted by itself is processed on the assumption that the correct Bi signal is transmitted by the image processing apparatus.

The image processing apparatus sends a "STOP" command to the digital color copying machine for the purpose of notifying the stop or end of the sending of the image data (Bi signals for each color).

[0006]

However, in the above-mentioned conventional example, there is only a time series promise that the PSYNC signal is sent from the digital color copying machine to the image processing apparatus in the order of M, C, Y and K. Therefore, if the PSYNC signal is lost for some reason, noise is placed on the PSYNC signal line, or the STOP command is not input to the digital color copying machine, various problems occur.

That is, the PSYNC signal may be missing for some reason, or the image data Bi signal transferred from the image processing apparatus to the digital color copying machine may have a frame shift. For example, when the M PSYNC signal is missing, as shown in FIG.
i signal is sent, and thereafter, Y is applied to K PSYNC signal.
Bi signal will be sent.

On the contrary, as shown in FIG. 9, the PSYNC of Y
If a noise appears between the signal and the PSYNC signal of K, and this is erroneously recognized as the PSYNC signal, the image processing apparatus sends a Bi signal of K in response to the noise, and the K plane is omitted in the digital color copying machine. , C for the next page
Of the Bi signal of K is output instead of the Bi signal of K.

Further, as shown in FIG. 10, when some trouble occurs on the image processing apparatus side and the Bi signal and the STOP command cannot be supplied to the digital color copying machine,
The system may be in a blank runaway condition that continuously outputs blank paper.

An object of the present invention is to provide an image processing system which does not cause such a problem.

[0011]

An image processing system according to the present invention is an image processing system composed of a digital color copying machine, an image processing apparatus and a host computer. B of each color transferred from the image processing apparatus to the digital color copying machine in synchronization with each PSYNC signal to
An error detection code frame is provided in the i signal, and the digital color copying machine inspects the data from the image processing apparatus for at least one of a predetermined time and a predetermined number of pixels from the PSYNC signal.

[0012]

By the above means, it becomes possible to easily detect a missing PSYNC signal or a PSYNC signal with noise. As a result, the abnormality can be immediately detected, the runaway can be suppressed, and the runaway can be quickly stopped.

Further, the digital color copying machine is
Since the data from the image processing apparatus is inspected for at least one of the predetermined time and the predetermined number of pixels from the PSUSYNC signal, it is possible to detect the blank paper output and suppress the blank paper runaway.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows a timing diagram of a first embodiment of the present invention. FIG. 1 (1) shows an image synchronization signal PSYNC sent from a digital color copying machine to an image processing apparatus, and 10, 12, 14, and 16 are C, M, Y, and K, respectively.
Is an individual PSYNC signal corresponding to each frame.

FIG. 1B shows the Bi signal transmitted from the image processing apparatus to the digital color copying machine in synchronization with the individual PSYNC signal, and 18, 20, 22, and 24 are C, M, and Y, respectively. , K frame.

FIG. 1C shows a detailed structure of the C frame 18. After the 8-bit error detection code frame,
Image data is arranged. The first 3 bits C0, C1, C2 of the error detection code frame are the identification code of each frame, and the remaining 5 bits C3, C4, C5, C6, C
7 is the PSY from the digital color copying machine
It is a count value indicating whether the signal is a Bi signal with respect to the NC signal.

The digital color copying machine checks the error detection code of the received Bi signal with the algorithm shown in FIGS.

In FIG. 2, it is checked whether the frame identification code of the leading 3 bits C0 to C2 corresponds to the PSYNC signal transmitted immediately before (S1). If they correspond, the subsequent 5-bit C3 to C7 count value is compared with the number of PSYNC signals issued by itself (S2). If they match, the Bi signal from the image processing apparatus is judged to be valid (S3). If S1 and S2 do not match, the PSYNC signal does not correspond to the input Bi signal (S
4).

A 5-bit counter cannot detect a frame if it shifts by 8 screens or more, but there is no problem if the number of bits is increased as necessary.

In the digital color copying machine, as shown in FIG. 3, when the contents of the count values of C3 to C7 of the error detecting code are not incremented as "00000" or "11111", the blank runaway occurs. Judge that you are in a state.

In the above embodiment, 8 bits are allocated to the error detecting code, but it may be 4 bits as shown in FIG.
The leading 3 bits C0, C1, C2 are the frame identification code as before, and the 4th bit C3 is the page flag. That is, C3 indicates that when a plurality of image data is sent from the image processing apparatus to the digital color copying machine,
This flag is set to "1" when the content of the current frame is the same as the previous frame, that is, the arbitrary frame of the previous page.

The digital color copying machine checks the error detection code shown in FIG. 4 of the received Bi signal with the algorithm shown in FIGS.

In FIG. 5, the leading 3-bit frame identification code C0 to C2 is used to check whether or not the frame identification code corresponds to the PSYNC signal transmitted immediately before. If they match, it is determined to be valid. In this embodiment, when the PSYNC signal is deviated by a multiple of 4, it cannot be detected, but at the same time, noise is mixed into the PSYNC signal by a multiple of 4, or the PSYNC signal by a multiple of 4 is also missing. This situation is not realistic, so there is no problem. In the structure of FIG.
The judgment process in the digital color copying machine can be simplified.

In the digital color copying machine, as shown in FIG. 6, the Bi signal does not come (that is, all 0) immediately after issuing the C PSYNC signal and immediately before issuing the C PSYNC signal on the next page. If it is, it is determined that the blank sheet is out of control.

[0026]

As can be easily understood from the above description, according to the present invention, it is possible to detect runaway of the image processing system and reduce unnecessary output of the gist. Furthermore, the stability of the system can be increased.

[Brief description of drawings]

FIG. 1 is a signal structure diagram of a first embodiment of the present invention.

FIG. 2 is a PSYNC-to-image data correspondence determination algorithm in the embodiment shown in FIG.

FIG. 3 is a blank sheet runaway detection algorithm in the embodiment shown in FIG.

FIG. 4 is a signal structure diagram of a second embodiment of the present invention.

5 is an algorithm for determining the correspondence between PSYNC and image data in the embodiment shown in FIG.

6 is a blank sheet runaway detection algorithm in the embodiment shown in FIG.

FIG. 7 is a normal timing diagram between the image processing apparatus and the digital color copying machine.

FIG. 8 is a timing diagram in the case where the M PSYNC signal is missing.

FIG. 9 is a timing diagram when noise is placed on the PSYNC signal line.

FIG. 10 is a timing diagram when the STOP command does not reach the digital color copying machine.

[Explanation of symbols]

10: C PSYNC signal 12: M PSYNC signal 14: Y PSYNC signal 16: K PSYNC signal 18: C frame 20M frame 22: Y frame 24: K frame

Claims (1)

[Claims] 1. An image processing system comprising a digital color copying machine, an image processing apparatus and a host computer, wherein the image processing apparatus is synchronized with each PSYNC signal from the digital color copying machine to the image processing apparatus. An error detection code frame is provided in the Bi signal of each color transferred from the digital color copying machine to the digital color copying machine, and the digital color copying machine performs the image processing for at least one of the predetermined time and the predetermined number of pixels from the PSYNC signal. An image processing system characterized by inspecting data from a device.