JPH0370262A - Image scanner control circuit - Google Patents

Abstract

PURPOSE:To improve the processing performance by setting a register value according to an original size to be read and applying a coincidence signal output resulting the comparison of a comparator to a CPU. CONSTITUTION:At first a CPU 1 sets the number of subscanning signals to a register 2 when the length (y) of an original G is scanned by a scanner S and a counter 3 counts the subscanning signal outputted from the scanner S when being moved in the subscanning direction (in the direction of arrow). Thus, as soon as a carriage mounting a sensor of the scanner S finishes the scanning of the original G, the content of the register 2 and the counted value of the counter 3 are coincident. That is, the coincidence signal is interrupted from a comparator 4 to the CPU 1 to make the input of a picture data to a personal computer complete. In this case, the scanner S applies the remaining scanning of the readable range although no picture data is outputted. The succeeding data processing is attained without waiting for the end of the scanning of the scanner S.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image scanner control circuit for inputting image data such as graphics and photographs in a personal computer or a DTP (desktop publishing device).

(Prior Art) In recent years, image scanners (hereinafter simply referred to as scanners) have come to be used to input image data such as figures and photographs into personal computers, DTPs, and the like.

Figure 3 shows an example of the output signal waveform of the scanner, where a is a start/end signal that controls the start and end of reading images such as figures, and b is data in the main scanning direction of one line (one resolution). A main scanning signal indicating that C is valid.
d is the image data output in the main scanning signal, and d is the sub-scanning signal, which sends out one pulse each time the carriage carrying the sensor moves one row. e is a clock signal for synchronizing the image data C.

While outputting the image data signal as described above, the end of the scanner's document reading is determined by the level change of the start/end signal a from L level (low level) to H level (high level) as shown in Figure 4. This is done by inputting an interrupt from 31 to a CPU (central processing unit) 33 in a personal computer or the like 32.

(Problems to be Solved by the Invention) As described above, in the conventional configuration, the end of document reading is detected by means of applying the start/end signal a of the J scanner output to the CPU.

Even if the original is smaller than the original size that can be read by the scanner, the scanner always waits for a change in the level of the start/end signal a, which is generated after the last scan of a predetermined original size, to complete reading. That is, since the time required for reading the document by the scanner is constant regardless of the size of the document to be read, there is a problem in that time is wasted and the function of the single-image data input system is degraded.

The present invention aims to provide a scanner control circuit that solves the above-mentioned problems.

(Means for Solving the Problems) The present invention has achieved the above object by providing a counter that counts the number of pulses of a sub-scanning signal generated by a scanner, a register that can arbitrarily set a register value, and a counter output and a register. This is achieved by a configuration in which a register value is set according to the document size to be read, and a match signal output compared by the comparator is applied to the CPU.

(Function) According to the present invention, by setting the registration value according to the length of the original, when the counter value of the sub-scanning signal matches the set value, a matching signal is sent to the personal computer or DTP into which image data is input. The signal is applied to the CPU, and input of image data is completed. That is, the CPU can perform other processing while the scanner scans the remaining document size up to a predetermined original size, and the image processing time of a personal computer or the like is shortened.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.
S is a scanner, P is a CPU (1) included in a personal computer or DTP (hereinafter referred to as a personal computer, etc.) that inputs image data, and 2 is a register that allows register values to be set directly from the CPUI by keyboard operation of a personal computer, etc.
3 is a counter that counts the sub-scanning signals generated by the scanner, and 4 is a comparator that compares the register value set in register 2 and the sub-scanning signal count output of counter 3. If the comparison results match, a match signal is issued. is the CPUI
is applied to

Figure 2 is a diagram showing an example of reading, where G is the document to be read whose length in the sub-scanning direction is y, R is the readable range of the scanner S, and the length in the sub-scanning direction is Y (where Y＞
y). First, the number of sub-scanning signals when the scanner S scans the length y of the document G is set in the register 2 using the CPUI shown in FIG. Next, the counter 3 counts the sub-scanning signal outputted every time the scanner S moves in the sub-scanning direction (arrow). Thereby.

At the same time as the carriage carrying the sensor of the scanner S finishes scanning the document G, the registration value of the register 2 and the count value of the counter 3 match. In other words, inputting the image data to the personal computer or the like is completed by causing the comparator 4 to interrupt the CPUI with the coincidence signal. At this time, the scanner S scans the remaining readable range.

It does not output image data, but it does. In other words, the personal computer or the like can perform the next data processing without waiting for the scanner S to complete scanning.

(Effects of the Invention) As is clear from the above explanation, the present invention can be applied to personal computers and DTs.
The time required by the P main body to request processing from the scanner is shortened depending on the size of the document, and therefore the performance of the entire system is improved, which has the effect of leading to improved production.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is an auxiliary diagram for explaining FIG. FIG. 4 is a diagram showing a conventional CPU interrupt at the end of data reading. 1...CPU, 2...Register, 3...
Counter, 4...Comparator, S...Image scanner (abbreviated as scanner), P...PC, etc., G...Original, R...Readable range of the scanner.

Claims (1)

[Claims] A sub-scanning signal that is output as one pulse each time the carriage of the image scanner moves by one resolution in the sub-scanning direction, a counter that counts the number of pulses, a register that can set an arbitrary count value, and these. Equipped with a comparator that compares the counter output with the register setting value,
A registration value is set in the register according to the size of the original to be read, the count value of the sub-scanning signal pulse of the counter is compared with the count value of the sub-scanning signal pulse by the comparator, and the matching signal is applied to a CPU included in a personal computer etc. that processes image signal data. An image scanner control circuit characterized in that the input of image data is terminated.