JPH02203384A - Image input device with synchronous window - Google Patents

Abstract

PURPOSE:To minimize the load on the side of a data processor by sampling an image signal when an address signal indicates a specific address range and deciding whether the sample image signal meets specific requirements. CONSTITUTION:The device is provided with a range setting means 20 which outputs the sampled signal of the image signal only when the address signal indicates the specific address range and a decision means which decides whether or not the image signal in the sampling area meets the specific requirements and outputs the decision result. For the purpose, the image signal is sampled only when the specific requirements are met and then processing for the limited area can be performed fast. Consequently, an image can securely be inputted by the minimum frequency of data processing.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention captures an image of a subject such as a liquid crystal display, and uses a synchronization window to determine whether or not the image in a predetermined range meets predetermined conditions. The present invention relates to an image input device that performs arithmetic processing on image signals, and particularly relates to an image input device that can process image signals of a subject such as a periodically blinking liquid crystal display at high speed.

[Conventional Technique 1] When inputting the status of an object whose surface changes periodically, such as a display that shows blinking numbers or letters, for the purpose of product inspection, conventional techniques By inputting image signals several times at a cycle sufficiently shorter than the blinking cycle and performing predetermined arithmetic processing on each image signal, it is determined whether the display is being performed normally in each blinking state. Ta.

[Problem to be solved by the invention]

In order to determine whether or not the display is performed normally in each state of blinking, it is necessary to reliably capture image signals in the state in which numbers or letters are displayed and in the state in which they accompany them. To do this, it is necessary to input the image signal and perform arithmetic processing a large number of times, for example, about IO times. Therefore, there is a problem that an excessive burden is placed on the data processing device and the overall processing time becomes longer. Furthermore, even if the number of inputs was increased, the blinking state could not be captured with 100% certainty, so the possibility of misjudgment could not be completely eliminated.

Accordingly, it is an object of the present invention to provide a synchronization window that can reliably input the state of a subject whose display state changes periodically, such as blinking, while minimizing the burden on the data processing device side. An object of the present invention is to provide an image input device.

[Means to solve the problem]

An image input device having a synchronization window according to the present invention, which was created with consideration for the above-mentioned purpose, includes an imaging means for outputting an address signal and an image signal synchronized with the address signal, and a data processing unit for the image signal. and a range setting means for outputting a sampling signal of the image signal only when the address signal indicates a predetermined address range, and an image signal of the area sampled by the range setting means. and determining means for determining whether or not the image signal satisfies a predetermined condition and outputting a determination result, and the data processing means performs data processing of the image signal according to the determination result of the determining means. This is a characteristic feature.

[For production]

Focusing only on a part of the area where the state changes in the subject, it is determined whether or not a predetermined condition, for example, a condition for displaying blinking, is satisfied in that range, and as a result of the determination, a predetermined Set the image signal to be sampled only when the following conditions are met. In this way, processing for a limited area can be performed at high speed, so that the determination result of the determination means and periodic changes in the subject can be synchronized. Therefore, if data processing is performed according to the determination result, the state of the entire image due to periodic changes in the subject can be reliably inputted with a minimum number of times.

〔Example〕

FIG. 1 is a block diagram showing a liquid crystal display inspection device as an embodiment of an image input device according to the present invention.

In the figure, a camera 10 comprising, for example, a CCD camera outputs an analog video signal and digital X and Y signals representing X and Y coordinates. The video signal is converted into a digital signal of a predetermined number of bits by the analog-to-digital converter 12, and is input to the video memory 14 together with the X and Y signals.

On the other hand, the range setting circuit 20 acts as a synchronization window.
An analog format video signal and X and Y signals are also input to the binarization circuit 22, and the video signal is supplied to the binarization circuit 22 only when the X and Y signals have coordinates within a preset area. The binarization circuit 22 has a brightness that can distinguish between when the characters or numbers on the liquid crystal display 50 to be inspected are on (black pixels) and when they are off (white pixels). A voltage vo corresponding to this is set, and a logic "1" is output for a black pixel, and a logic "'0" is output for a white pixel. The counter 24 counts the number of signals corresponding to black pixels among the signals output by the binarization circuit 22, and is further controlled by the signal from the range setting circuit 20 to count the number of signals corresponding to black pixels within a predetermined address range. Print a number.

The determination circuit 26 determines whether the blinking state of the display 2g50 is on or off by comparing the output of the counter 24 with a preset value. As will be described later, the number of values preset in the determination circuit 26 is not necessarily one, and more than one value may be set in advance.

The judgment circuit 16 supplies the video data stored in the video memo Uld to the arithmetic circuit 18 according to the judgment result of the judgment circuit 26. In the arithmetic circuit 18, for example, in each blinking state, arithmetic processing is performed to determine whether each display segment is correctly turned on or off.

FIG. 2 is a diagram showing an example of an address range set by the range setting circuit 20. The display 50' displays the character string "
ABC” is turned on and off at regular intervals,
When testing such a display, check the shaded area 5 in the diagram.
By setting the address range corresponding to the area represented by 2, blinking of the entire character string "ABC" can be detected.

Figure 3 shows the character string “AB” blinking at a predetermined period.
This shows an example of address range settings when testing a display device 50' that displays "C" and a numeric string "123" that blinks at a different phase or cycle.

The address range consists of a hatched area 54 for detecting blinking of the character string "ABC" and a hatched area 56 for detecting blinking of "123". In this case, the judgment circuit 26 (Fig. 1) contains "123" when both are on, when only "ABC" is on, and when "ABC" is on.
Three threshold values are set to determine the output of the counter 24 when only one is on and when both are off. Alternatively, the “ABC” area and “123”
In order to separately judge the area of ``, the circuits (22, 24, 26) after the range setting circuit can be provided separately.In this case, the reference voltage of the two binarization circuits and the two judgment circuits can be separately provided. The threshold values of can be set to different values.

〔Effect of the invention〕

As described above, according to the present invention, there is provided an image input device that can reliably capture the state of a subject in a minimum number of times, making it possible to save memory and, for example, changing the period of blinking. Even in such cases, it can be captured reliably.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of an image input device having a synchronization window according to the present invention, and FIGS. 2 and 3 are schematic diagrams illustrating an example of setting an address range. In the figure, 10... Camera 12, 14, 16, 18, 20, 22, 24, 26, 50.50', 50' A/D converter video memory judgment circuit calculation circuit range setting circuit Binarization circuit counter judgment circuit display

Claims (1)

[Scope of Claims] An image input device comprising an imaging means for outputting an address signal and an image signal synchronized with the address signal, and a data processing means for performing data processing on the image signal, comprising: range setting means for outputting a sampling signal of the image signal only when indicates a predetermined address range; determining whether the image signal of the area sampled by the range setting means matches a predetermined condition; An image input device comprising means for outputting a determination result, and the data processing means performs data processing of the image signal according to the determination result of the determination means.