JPS593060B2 - Facsimile automatic destination reading circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses an automatic destination reading circuit for a facsimile machine, and in particular, uses a transmission document in which destination entry columns to be filled in in the destination designation mark are arranged based on a reading timing mark (hereinafter referred to as a start mark). Regarding the automatic destination reading circuit in case.

In the past, when communicating by facsimile, an operator would manually call the recipient and then send multiple documents using an automatic paper feeding mechanism. Of the manuscripts, manuscript A is automatically sent to the other party, and manuscript B is automatically sent to the other party.

An example of a transmission document used in such a facsimile machine is as shown in FIG.

That is, an address entry field 3 is provided at the top of the original 1 with a start mark 2 of a predetermined length as a reference, and this is
-N columns, and a desired partner is designated by marking 4 according to a predetermined code. When reading which column is designated using such a document, a start mark detection method that indicates the reference position of the column becomes important. FIG. 2 shows a conventionally used start mark detection circuit, and FIG. 3 shows signal waveforms.

The start mark 2 and destination designation mark 4 on the original 1 as shown in FIG. The scan start signal 113, which is converted into , resets the flip-flop 15|19 in advance. The scanning image signal 111 is input to the shift register 12 every pulse of the sample pulse 112, and when the scanning image signal 111 is black for three consecutive pixels (three pulses of the sample pulse 112), the AND circuit 13
The output 131 of is set to "1", and the σ output 151 of the flip-flop 15, which is a storage circuit, is set to "o". The AND circuit 13 is mainly used to protect against erroneous start mark detection due to noise 1110 on the scanning image signal 111 caused by dirt on the original 1. After that, the counter 16, which is a counting circuit, outputs a sample pulse 1 for the length of the start mark 2.
12, and the AND circuit 17 generates a signal 171 corresponding to the vicinity of the trailing edge of the start mark 2. On the other hand, the AND circuit 14 detects a change point from a black pixel to a white pixel in the scanning image signal 111, and its output 141 is input to the AND circuit 18 together with the output 171 of the AND circuit 17, and the start mark 2 Trailing edge detection is being performed. When the output 181 of the AND circuit 18 becomes 1, the output 191 of the flip-flop 19 for detecting and holding the start mark becomes 1.
", the other control circuits MD are notified that the same start mark has appeared in the scanning image signal 111, and reading of the column is started based on this point. Note that the scanning image signal 111 in FIG. The signal 1112 shown in 2 is a noise caused by a white spot in the start mark 2, and the signal 1110 is noise caused by dirt in a column.However, according to the conventional method, there is a dirt 5 on the original as shown in FIG. In this case, the AND circuit 13 and flip-flop 15 are activated by this dirt, and the start mark trailing edge detection signal 181 indicating the start of column reading is erroneously generated, which may cause erroneous column reading and misdirection of the destination. It happened often.

As a countermeasure against this problem, it is necessary to ensure that the document is not soiled, but there has been a desire for a circuit that can read the destination with high reliability even if the document is slightly soiled. SUMMARY OF THE INVENTION An object of the present invention is to provide a destination reading circuit that can read a specified destination position with a simple circuit configuration and with high reliability even if the destination entry field is dirty.

According to the present invention, a circuit A for detecting continuous black pixels in a scanning image signal, a circuit B for detecting continuous white pixels, and a memory circuit for holding a set state and a reset state by circuits A and B, respectively. , a counting circuit that operates when the memory circuit is in a set state and counts a number corresponding to the length of the start mark, and a differentiation circuit that detects a change point from a black pixel to a white pixel in the scanning image signal. , a facsimile destination reading circuit can be obtained by detecting the trailing edge of the start mark by ANDing the output of the counting circuit and the output of the differentiating circuit.

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 5 shows a start mark detection circuit according to an embodiment of the present invention, and FIG. 6 shows its signal waveform.

In the figure, parts with the same symbols as in FIG. 2 have exactly the same functions. In FIGS. 5 and 6, when the dirt 5 on the original 1 is equal to or more than three pixels in the scanning image signal 111, the Q output of the flip jack 15 is set to O as in the conventional system. However, if the width of the stain 5 is less than or equal to the start mark, the scanning image signal 111 returns to a white pixel, so the output 2 of the AND circuit 20
If, for example, three consecutive white pixels occur due to 01, the flip-flop 15 is reset and the state is returned to detecting the start mark again. In this case, the AND circuit 20 does not reset the flip-flop 15 unless there are three consecutive white pixels. This is because there is a possibility that there is a white spot of about 1 or 2 pixels in the image. This series of operations is shown in waveforms 1515, 1512, and 1514 of waveform 151 in FIG.

The operation after detecting the front end of the start mark is exactly the same as that of the conventional example described above, so a description thereof will be omitted. According to the present invention, it is possible to obtain a destination reading circuit with a simple circuit configuration and high reading reliability even when the destination entry column is dirty.

[Brief explanation of drawings]

Figure 1 is a diagram showing an example of a transmitted document used to specify a destination, Figure 2 is an example of a conventional start mark detection circuit, and Figure 3 is its signal waveform, showing a state in which reading is performed normally. , Fig. 4 shows the signal waveform of Fig. 2, showing a state where a reading error occurs due to dirt on the original, Fig. 5 is a circuit diagram showing one embodiment of the present invention, and Fig. 6 shows the signal waveform. be. DESCRIPTION OF SYMBOLS 1... Manuscript, 2... Start mark, 3... Address entry field, 11... Image signal circuit, 12... Shift register, 15... Flip-flop (memory circuit), 16
...Counter, 19...Flip Flop.

Claims (1)

[Claims] 1. In the automatic destination reading circuit of a facsimile machine, which has the function of reading the column position where the destination is specified in the destination entry field consisting of multiple columns arranged based on the reading timing mark on the transmission document, the continuous A circuit A that detects a scheduled number of black pixels, a circuit B that detects a scheduled number of continuous white pixels, a memory circuit that holds a set state and a reset state respectively by circuits A and B, and the memory circuit is set. a counting circuit that operates when the reading timing mark is in the state and counts a number corresponding to the length of the reading timing mark; and a change point detection circuit that detects a change point from a black pixel to a white pixel in the scanning image signal; An automatic destination reading circuit for a facsimile machine, characterized in that a trailing edge of a reading timing mark is detected by a logical product of an output of the circuit and an output of the change point detection circuit.