SU849195A1 - Device for converting data to video signal - Google Patents

Description

The invention relates to computing and can be used in raster scanned information display devices. A video signal shaping device is known comprising a shift register for converting a parallel code to a serial, a shift register for receiving information from the MOZU, a symbol generator with a recording unit and decoders, and a control unit, which makes it possible to overwrite the memory of the symbol generator in the process. work without rework device. In the course of operation, the codes of the characters that make up the image are transferred from the external MOZU to the address input of the memory of the symbol generator. At the same time, the code for scanning the number of the symbol scan line is transferred to other bits of the address input from the control circuit. At the output of the MOZU, a character string sweep code is obtained that is converted in the shift register into a serial code for controlling the video amplifier l}. The drawback of the device is the need to have two storage devices: the memory of the symbol generator and the external MOZU for storing the character codes. In addition, there is no possibility of changing the image format, i.e. the number of character lines and the number of characters in a line, depending on the nature of the image. The closest in technical essence is a device comprising a clock generator, a television scan line counter, a character row counter, a character counter in a row, a symbol generator, a switching circuit, a video driver, a memory. The outputs of the switching circuit are connected to the control inputs of a character counter in a row, a character row counter, a scan line counter, and a clock generator so as to change the size of the displayed characters. The device may contain a television receiver connected to the G2 video signal generator. The drawback of the device is the need to have two memories, one for generating symbols, another for storing codes of displayed symbols. Moreover, it is impossible to rewrite the contents of the symbol generator during the work without modifying the device, therefore, to work with different alphabets, it is necessary to increase the memory capacity of the generator characters: i.e. operation scope. In this case, when the character sizes are changed, the number of the element decomposition of the characters does not change, but the size of the decomposition element increases, i.e. There is no possibility of choosing the optimal number of character decomposition elements depending on the type of image. The purpose of the invention is to simplify the device and expand its area of application due to the possibility of optimally encoding information by redistributing the amount of memory between the array of fragment codes and the array of word codes of fragment scanning. The goal is achieved by the fact that a device for converting information into a video signal containing successively connected control and synchronization unit, address generator and memory unit connected to the control and synchronization unit, and a video signal generator associated with the control and synchronization unit are inserted into the control unit. format connected to the control and synchronization unit and the address generator, and two groups of AND elements, the first inputs of the AND elements of both groups are connected to the control unit and synchronous second inputs are connected to the outputs of the memory unit, the third inputs of the elements of the first and second groups are connected respectively to the control and synchronization unit and the address former, and their outputs are connected to the video signalformer. Besides the address, the address driver contains two groups of inverters and mutator, the inputs of which are connected to the outputs of the inverters of both groups. The drawing shows the functional diagram of the proposed device. 54 The device contains a block 1 of control and synchronization, a shaper 2 of the address, a block 3 of memory, a first 4 and a second 5 groups of elements And, a shaper 6 of video signals, a block 7 of format control. Shaper 2 addresses contains the switch 8, the first 9 and the second 10 groups of inverters. Memory unit 3 has an input 11 for recording information from external sources. The address generator 2 has an input 12 for setting the address when writing information from an external source to the memory unit. Switch 8 and memory block 3 have input 3 for supplying control signals from an external source. The format control unit 7 has an input 14 for recording a format code from an external source. The video shaper 6 has an output 15 for connecting to a television, vision indicator or another type of indicator with raster reconnaissance (not shown). . The device works as follows. The information to be converted to a video signal is divided into fragments during encoding. Each fragment is divided into sweep words, the sweep word contains sweep elements. Each fragment is assigned an address. Each fragment address corresponds to a cell in the block in which the code of the fragment displayed at this address is recorded. The array of codes of the fragments displayed on the indicator screen occupies cells with lower addresses in the memory block. A fragment with a zero address corresponds to a zero cell in the memory block. The codes of all the scan words of all types of fragments used in the construction of the image are located in the memory block in the upper address area. Each type of fragment is assigned a code that provides unambiguous communication with the address of the cells in which the codes of the word fragments are stored. The codes of the fragments converted into a video signal are recorded in the memory block when the control signals are received at input 13. The code values are received at the input 11 of memory block 3, and the addresses of the fragments are input 12 of the driver 2 addresses where they are sent directly switch 8. The word codes of the fragment sweep are transferred to memory block 3, when control signals arrive at input 1, the code values arrive at memory 11 of memory 3, the address values arrive at input 12 to form address 2, which through the first groups for inverters, they are fed to the switch 8 so that the CBD of the zero scan line of the zero scan word for a fragment with a zero code is written into the cell of the memory block with the most significant bit. Thus, the memory filling is conducted from two sides: from the side of lower addresses, data on the distribution of fragments on the screen is entered, and from the side of the older ones - programs for the construction of separate fragments. The total amount of information should not exceed the volume of the memory block. Placing the boundary between these types of information depends on the format. With an increase in the number of decomposition elements of each fragment, this boundary moves to the address area, and the number of fragments placed on the screen decreases. I The conversion of fragment codes into a video signal is performed synchronously with the scanning of a beam or other drawing body on the indicator screen and is performed in two stages. First, the code of the fragment in the region of which the beam is located is read. This code is fed through the second group 5 of the elements AND and the inverters of the second group 10 to switch 8. At the second stage, the code of the fragment scan word is read out and transferred from the memory through the first group A of the elements AND to the video signal generator 6. The address of the cell storing the fragment code is generated by the shaper 2 addresses from the fragment number codes in the string and the fragment line number codes. The address of the cell storing the code of the fragment sweep word is generated from the fragment code read in the first conversion step and received at the input of the switch 8 through the second group of 10 inverters, and the word number code. The values of the high-order address bits are equal to the inverse values of the fragment code, and the low-order ones to the inverse values of the word number bits. Thus, the shaper 6 of the zero scan line of all fragments placed in the zero line of fragments, then the word codes of the first word of all fragments placed in the zero line of fragments, etc. are issued to the video signal generator 6. until the word codes of the sweep are placed on the last scan line of the zero line of fragments. Then one is added to the fragment row counter, and the conversion of the next string of fragments begins. The rewriting of the format code is carried out under the influence of control signals from external sources. Writing into the control unit 7 the format of the code arriving at input 14. In various embodiments of the device, various ways of generating addresses and allocating memory can be used. For example, the array of fragment codes can be located in the upper memory address area, and the array of fragment code codes can be located in the lower memory address area. The amount of equipment required to build a device is reduced compared to known devices with similar characteristics due to the use of a memory block with one common information sampling system for a sequence of fragment codes and a sequence of fragment scan codes. A separate character generator memory is excluded from the device. There is a reduction in the amount of information needed to encode an image, since it is possible for each particular image or class of images to use the optimal format and the optimal set of fragment types. The optimal fragment sizes are determined by filling the image, configuration and repeatability of individual parts of the image, for example, splitting text into 1024 fragments (familiarity) with a fragment size of 5 decomposition elements horizontally and 7 lines of decomposition vertically with a constant interval is widely used to indicate the text image. between signs 2 elements. The number of types of fragments (alphabet) for the Russian text is 64 (including numbers, characters of the copy 784

no mathematical signs). Character code - 6 bits. The total amount of information for describing such an image is 1024 x 6 + 64 x 35 6144 + 8384 bits. .

In the case of graphic information output divided into 1024 familiarity, the vertical size of each fragment is approximately doubled so that it is possible to get lines without breaks. The amount of information required is more and is 1024 x x 6 + 64 x 98 6144 + 6272 12416 bits ...

If a graphic image of the type of schemes is displayed, then, with the size of the fragments, the amount of information necessary for encoding the image is significantly reduced, as the fragment code array, which is individual for each image, is reduced. The array of scan layer codes may increase, but since the set of fragment types is the same for all single-type images, the total amount of information for encoding a group of single-type images can be significantly smaller.

Reducing the amount of information needed to encode images reduces the amount of memory and the amount of equipment used in information and control systems to display information and allows raster display devices to be used to display mimic diagrams, simple drawings and other simple graphics. .

In addition, the flexibility of the characteristics of the proposed device allows a reduction in the number of types of display devices used in enterprises for various tasks. This simplifies operation and reduces backup costs.

Claims (2)

1. A device for converting information into a video signal comprising 58 sequentially connected control and synchronization unit, address shaper and memory unit connected to the control and synchronization unit and video signal shaper associated with the control and synchronization unit, characterized in that, in order to simplify the device and extend its application area due to the possibility optimal coding of information by redistributing the amount of memory between the array of fragment codes and the array of code words of the sweep. fragments, the format control block is inserted into the device, under Connected to the control and synchronization unit and the address generator, and two groups of elements AND, the first inputs of elements AND of both groups are connected to the control and synchronization unit, the second inputs to the outputs of the memory unit, the third inputs of elements AND of the first and second groups are connected respectively to the control and synchronization unit and the address driver, and their outputs to the video driver. 2. Device prp. 1, characterized in that the address driver contains two groups of inverters and a switch, the inputs of which are connected to the outputs of the inverters of both groups. Sources of information taken into account in the examination 1.L skovskiy Yu.P. and Chuchkin V.I. High-speed generator of standard signals for the screen console raster type. Seminar material. Device for operational interaction and display of information. Moscow House of Scientific and Technical Propaganda. F.E. Dzerzhinsky, M., 1975. 2. US patent number 3659283, cl. 340-324 A, published. 1974 (prototype).