JPH0222980A - Picture memory device - Google Patents

Abstract

PURPOSE:To easily and rapidly perform the memory test of a picture memory device by providing a data conversion part to perform the bit conversion of the most significant bit(MSB) and the least significant bit(LSB) of binary digital video data. CONSTITUTION:The data conversion parts 3 to perform the bit conversion of all six bits including the MSB and the LSB are provided between an A/D conversion part 2 and a picture memory part 4, and between the picture memory part 4 and a D/A conversion part 5, respectively. And it follows that the data conversion part 3 is used in such a way that the correspondence of the data bit of the picture memory part 4 is switched by switching the directions of the MSB and the LSB of the data converted to binary six bit digital data for all six bits, and a large analog error level is generated by allocating the bit allocated only as a low-order bit to a high-order bit. In such a way, it is possible to easily perform the memory test by displaying even the reproduced picture of a memory error easy to miss on a monitor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image memory device that digitizes a video signal from a television camera, writes it into a semiconductor memory, and stores it.

[Conventional technology]

FIG. 8 is a block diagram of a conventional image memory device. In the figure, (1) is an analog input section that performs analog processing of video signals from a camera, etc.;
1) is a D conversion unit that converts the analog video signal from 21 into digital data, (4) is an image memory unit that writes and stores the digital video signal from the D conversion unit (21), and (5) is an image memory unit that converts the analog video signal from the image memory unit (4). A DA converter (6) is a DA converter (5) that converts the read digital video data from the image memory into an analog signal when reproducing the read image.
An analog output section (71 is a monitor television) adds a synchronization signal and the like to the analog reproduced waveform from the standard television signal.

Next, the operation will be explained. In the explanation below, the number of bits of internal video digital data is 6 bits, which is the most commonly used bit number. The video input signal from a television camera, etc. is subjected to analog input processing such as amplification and removal of unnecessary frequency components by the analog input section (1), and then sent to the D conversion section (1).
2) is input as input data. Next, the D conversion section (
In 2), it is converted into 6-bit digital video data that is binarized according to the input analog input level, and the 6-bit data is transferred to the image memory (41) as write data in the image memory section (41). The written video data is stored in the image memory section (41).In the large image memory device, the video stored in the image memory section can be output as a standard television signal and played back. At this time, the image memory section performs a read operation, and digital video data to be reproduced and displayed is output from the image memory section (4).This output digital video data is input to the DA conversion section (5).DA The converter (5) outputs an analog signal according to the value of the input binary coded 6-bit data.The analog signal converted by the DA converter (5) is output as a synchronizing signal at the analog output section (6). It performs analog processing necessary for standard television signals, such as addition, and outputs it as a video output signal.

The output video signal is played back and displayed on a monitor television (7).

[Problem to be solved by the invention]

In conventional image memory devices, video analog signals are stored in the image memory section as binary coded digital data with fixed bit correspondence, so even if there is an error in the lower bits in the image memory section during product inspection, the analog reproduction output The error level is so low that it is difficult to find the error by looking at the playback screen, and the problem is that the error can be easily overlooked.

This invention was made in order to solve the above-mentioned problems, and its purpose is to provide an image memory device that allows a memory test of the image memory section to be easily performed by viewing the playback screen on a monitor with simple operations. shall be.

[Means to solve the problem]

The image memory device according to the present invention has M
A data converter is provided to convert all 6 bits including sB and LSB.

[Effect]

The data converter in this invention has two
M of data converted to evolved 6-bit digital data
SB (Most Significant) By swapping all 6 bits of LSB (Lowest Significant), the data bit correspondence in the image memory section can be swapped and used, and what was previously assigned only to the lower bits is replaced by the upper bits. By being assigned as bits, the analog error level is high, and even memory errors that would otherwise be overlooked can be easily tested by displaying a reproduced image on a monitor.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (1) is an analog input section, (2) is a conversion section that converts the analog input signal into binary coded 6-bit digital data, and (3) is the data direction of the MSB and LSB of the binary coded 6-bit digital data. a data conversion section that replaces all 6 bits; (4) an image memory section that stores the video information converted to digital data; and (51) a data conversion section that converts the read data from the image memory section (4) into an analog signal corresponding to the value. DA conversion section, (6) is an analog output section that adds synchronization signals necessary as a standard TV signal, [7] is a monitor TV that displays the video output from the analog output section (6), and (8) is a data conversion section. This is a changeover switch that changes control signals.

Next, the operation will be explained. A video input signal from a TV camera, etc. is input to the analog input section (1), where it is amplified and
Processing such as removal of unnecessary frequency components is performed and the wholesale conversion section (
2). Next, in the AD converter (2), the data is converted into 6-bit digital video data which is binarized according to the level of the input analog video signal. D conversion section (2
) is input to the data converter (3), and as shown in FIG. , LSH (not converted), and when the data conversion control signal is so', MSB, L
SB (outputs with all 6 bits in the D direction replaced and written into the image memory section (4) as write data. The image memory section (4) stores the written video data, and the image memory section ( When reproducing and displaying the video stored in the image memory section (4), the image memory section (41 performs a read operation, and the digital video data to be reproduced and displayed is output from the image memory section (4).!Image memory section (4
) is inputted as the third input, which performs exactly the same function as the one described previously, and according to the data conversion control signal, when it is 11', the data conversion control is performed without exchanging the MSB and LSB. When the signal is 0#, all 6 bits of MSB and LSH are switched and output.

As described above, when writing and reading from the WJ image memory section (41), the data conversion section (2) and the DA conversion section (5) are Image memory part (4) with bit correspondence matching
It becomes possible to change the bit correspondence.

The read data from the data converter (31) is input to the DA converter (6), which outputs an analog signal according to the value of the input binary coded 6-bit data.Analog output unit t
In the a+, analog processing required as a standard television signal, such as addition of an analog synchronization signal from the DA converter (6) and adjustment of the video level, is performed, and the signal is output as a video output signal. The video output signal is input to a monitor television (7) and reproduced and displayed.

Further, in the above embodiment, the case where 6 bits of binary coded data is stored in the image memory section (4) has been explained as an example, but the same effect can be obtained even if the number of data bits is 6 bits or more. Also, image mail, -1!
The same effect can be achieved not only in the converter section (41) but also in devices that handle a large amount of binarized data (for example, a PCM recorder, etc.).

〔Effect of the invention〕

As described above, according to the present invention, since a data conversion section is provided that performs bit conversion of MSB and LSH of %2-enhanced digital video data, it is possible to easily and quickly perform a memory test of an image memory device. There is.

[Brief Description of the Drawings] Fig. 1 is a block diagram of an image memory device that is an embodiment of the present invention, Fig. 2 is a detailed circuit diagram showing an embodiment of the data converter of Fig. 1, and Fig. 8 is a block diagram of an image memory device that is an embodiment of the present invention. 1 is a block diagram of a conventional image memory device. In the figure, (1) is an analog input section, (2) is a D conversion section, (3 is a data conversion section, (4) is an image memory section, (
5) is a DA conversion section, (6) is an analog output section, (11 is a monitor television, and (8) is a changeover switch. In the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] The analog input section performs analog processing such as amplifying the video input signal from a television camera and removing unnecessary frequency components, the AD conversion section converts the analog signal corresponding to the video input signal into a digital signal, and the AD conversion section a data conversion unit that performs bit conversion of MSB and LSB of the digital data; an image memory unit that writes and stores data from the data conversion unit; and a digital data that reads the image data stored from the image memory and writes the digital data to the image memory. A data converter that performs bit conversion similar to that performed in the actual case, a DA converter that converts data from the data converter into an analog signal, and a DA converter that adds a synchronization signal to the analog signal from the DA converter. An image memory device comprising an analog output section that performs analog processing and outputs a video signal as a standard television signal.