JPH03218576A - Document memory device - Google Patents

Abstract

PURPOSE:To display the image data of high resolution exhibiting sufficiently scanning capacity from an image scanner by storing high-density image data from the image scanner as it is, and reading it out in various kinds of reading modes at the time of read-out for displaying it on a CRT. CONSTITUTION:A read-out control means 6 is provided with a means 4 to read out the stored data of instructed banks 31 to 34 in response to a bank selecting instruction from a host device 5, the means 4 to thin an address set beforehand in response to a data thinning instruction from the host device 5, and the means 7 to thin read-out data set beforehand in response to a data thinning instruction. Accordingly, by thinning the data at the point of time when data is read in from a document memory 3, visual interchangeability can be given, and further, by switching the banks 31 to 34 of the document memory 3 as occasion demands, the block control of the image data can be executed. Thus, the image data of the high quality exhibiting sufficiently the scanning capacity from the image scanner is reproduced on the CRT.

Description

Detailed Description of the Invention Technical Field The present invention relates to a document memory device, and more particularly, to a document memory device for storing high-density image data from an image scanner, processing the image data under I/O command control from a main control unit, and displaying the image. CRT with limited area
The present invention relates to a document memory device for transferring documents to a computer.

Prior Art In this type of conventional document memory device, even if high-density data from an image scanner is directly transferred to a CRT, it cannot be displayed if the image display area of the CRT is limited.

Therefore, the image data from the image scanner is thinned out in the connection cable with the scanner (for example, by not connecting data signal lines of odd bits), and the timing of the data synchronization signal is used to Data assigned to odd addresses is used to change the data density and transfer the data to the CRT.

In this way, in conventional document memory devices, image data is stored in the memory by thinning odd data using the connection cable itself, and data that would normally be assigned to odd addresses is stored in the memory using a synchronization signal for data transfer to the CRT controller. is truncated, so only 174 image data of the data density sent from the image scanner are stored in the memory.

This is because the image display area of the CRT is limited, and the data capacity for display on the screen is sufficient. However, since the remaining 3/4 of the image data actually sent from the image scanner is discarded, the scanner's original scanning ability is fully utilized and CR
There is a drawback that image data cannot be displayed on the T screen.

Purpose of the Invention Therefore, the present invention was made to solve the drawbacks of the conventional ones, and its purpose is to store high-density image data from an image scanner as it is and transfer it to a CRT. By enabling various readout modes during display readout, high-resolution image data that fully utilizes the scanning ability of the image scanner can be transferred to C.
An object of the present invention is to provide a document memory device capable of RT display.

Structure of the Invention According to the present invention, there is provided a document memory that stores image data from an image scanner and includes a document memory that is divided into a plurality of banks, and a readout control means that reads out and controls display of the stored contents of the document memory. The read control means includes means for reading stored data in a designated bank in response to a bank selection instruction from the host device, and a means for reading data stored in a designated bank in response to a data thinning instruction from the host device; There is obtained a document memory device characterized in that the document memory device includes means for thinning out the addresses read from the bank, and means for thinning out preset read data from the bank in response to the data thinning instruction.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a system block diagram of an embodiment of the present invention.

The image scanner 1 is for generating image data, and the scanner interface 2 is for the image scanner 1.
It performs serial/parallel conversion of image data sent from the controller, generates write addresses, and controls write signals.

The document memory 3 has four memory banks 3 in this example.
It is divided into sections 1 to 34 and expands and stores image data.

The address selection and address generation section 4 has a function of generating an address for selecting one of the memory banks 31 to 34 in response to a command instruction from the main control section 5, and thinning out odd addresses.

The decoder 6 decodes commands from the main control section 5 and controls the address selection and generation section 4 and the data selection section 7. The data select section 7 switches between deriving 1-byte output data of one of the designated memory banks 31 to 34 or deriving thinned-out data.

Currently, document memory 3 is 512K bytes (128K bytes).
K by l-X4), each bank 31 to 3
Assuming that 4 is 128 Kbytes, a total of 19 address lines 11 (ABO to AB18) (19 bits) are required. However, due to the restriction that the capacity of the area that can be displayed on the CRT is 128 Kbytes, it becomes necessary to allocate 2 bits of the address lines ^Bl7 to AB1g to bank select.

This 2-bit address allows the four banks 31 to 3
One of the four banks is selected, and 128 Kbytes of image data becomes selectable.

Therefore, the address generation function of the address selection and address generation section 4 is configured as shown in FIG.

That is, using the latch circuit 14, DBO-DB7 (8 bits 1 byte) of the data bus line is
I30 to DBI are latched in this latch circuit 14 to generate 2-bit addresses AB17 to ABIg,
Hunk selection can always be performed from the main control section 5. Note that IOWRc indicates a 1/0 write/read command, and due to this command timing, latch circuit 1
4 latch operation is determined.

At this time, the bank selection output is the normal data bus line 1.
2 to the data select section 7, and is supplied from the multi-bus 10 to the CRT controller 8.

Even if the CRT is displayed by switching banks, it is not possible to view the entire image data at once, so a thinning function is required.

There are two types of thinning: address line thinning and data bus line thinning, and by performing these two thinning simultaneously, it is possible to reduce the document memory capacity to 1/4 of the original document memory capacity. .

Therefore, address line thinning will be explained first. Taking as an example the addresses ^02 to M^03 of the memory addresses H^00 to M^l9 connected to the document memory 3, the address lines of the image bus 10 are assigned numbers 8002 to 8 BOB. However, the address select circuit 15 of FIG.
) by shifting the address using the logic shown in
~8BO2 will be connected to 802~M^03 during this time, and the addresses will be thinned out.

Next, data bus line thinning will be explained. FIG. 4 is a partial circuit diagram of the data select section 7 shown in FIG. 1. For example, the data bus line of the memory bank 31 is
OO~MDBO7 (8 bits), and the data bus line of memory bank 32 is MDB1 [i~MDB23].
．． (8 bits), data transceiver 1
Each 8-bit terminal M16-M23 of data transceiver 16a is connected to an 8-bit data line of memory bank 31, and each 8-bit terminal MO-M7 of data transceiver 16C is connected to an 8-bit data line of memory bank 32.

The 8-bit terminals DO-D7 of both data transceivers 16a and 16c serve as corresponding bit inputs of the data transceiver 16d, and an 8-bit data bus DBOO-DB is connected to each terminal IA-8^ of the data transceiver 16d.
O7 is connected.

Also, only the even bits of the data bus lines of both memory banks 31 and 32 are collected and the data transceiver 1
6b, and the 8-bit terminals DO-D7 of this data transceiver 16b are connected to the corresponding 8-bit terminals I8-M22 of the previous data transceiver 16d.
It is 8A.

These data transceivers 16a, 16b, 1
A PAL (Programmable Array Logic) 17 for generating select signals is provided to control the data transceivers 16a and 6c.
, 16b, and 16c. It is assumed that the enable terminal E4 of the data transceiver 16d is always set to low level and activated.

The data select circuits or memory hunks 33 and 34 shown in FIG. derived.

In this configuration, first, the function of reading out the document memory by bank selection will be explained.
The data is sent to the address selection and address generation section 4 via the multi-bus 9, and the command is decoded by the command decoder 6.

As a result, one byte of data is sequentially read from the specified bank in the document memory 3, and the corresponding data transceiver of the data select section 7 is selectively enabled. As a result, the designated bank data is derived to the image bus 10, and the data is sent to the CRT controller 8, where it is displayed on the CRT.

To explain the thinning function, a thinning command is sent from the main control unit 5 via the multi-bus 9, and the command decoder 6 decodes this and selects the address sent from the image bus 10 to the address selection and address generation unit. The data is thinned out by the address thinning circuit shown in FIG. At the same time, the transceiver 16b is enabled in the data select section 7, and the odd-numbered bits of data are thinned out in the data select section.
It will be sent to the CRT controller 8 and displayed on the CRT.

Conventionally, as shown in FIG. 5, the output of the image scanner 1 is decimated by the scanner interface 2 into 12
8K bytes of document memory 3 and CR
The configuration is such that the data is read out via the image bus 10 by the T controller 8. That is, when the data from the image scanner is input to the document memory 3, it is already thinned out and stored.

Effects of the Invention As described above, according to the present invention, the memory has a capacity to store image data sent from an image scanner without being truncated, and the data is read from the document memory for image display. By thinning the data at the point in time, it is possible to maintain visual compatibility, and by switching the document memory bank as necessary, it is possible to manage the image data separately, thereby increasing the scanning ability of the image scanner. This has the effect of being able to reproduce high-resolution image data on a CRT that fully utilizes the image quality.

When applied to software, as a type of multi-window function, first project the thinned out image data on a CRT, move the cursor to a certain coordinate, memorize that coordinate, and start from that coordinate. By displaying data that has not been thinned out, it can be used as a zoom function, and by managing the division of image data on the document memory, the cursor position can be replaced with coordinates.
By making it correspond to the address of the document memory, there is an effect that it can be used as a scrolling function in the vertical, horizontal, and horizontal directions.

[Brief explanation of drawings]

FIG. 1 is a system block diagram of an embodiment of the present invention, FIG. 2 is a circuit diagram showing a specific example of the address generation function of the address selection and address generation section 4, and FIG. 3(A) is the address selection and address generation section. 3(B) is a diagram showing a truth table of the circuit in (A); FIG. 4 is a circuit diagram showing a specific example of a part of the data select section; FIG. 5 is a system block diagram showing the prior art. Explanation of symbols of main parts 1...Image scanner 3...Document memory 4...Address selection and address generation unit 5...Main control unit 6... ... Decoder 7 ... Data selection section 31 to 34 ... Memory bank

Claims (1)

[Claims] (1) A document memory device comprising: a document memory that stores image data from an image scanner and is divided into a plurality of banks; and readout control means for reading out and controlling display of the stored contents of the document memory, the device comprising: The read control means includes means for reading data stored in a designated bank in response to a bank selection instruction from the host device, and thinning out preset addresses in response to a data thinning instruction from the host device. and means for thinning a preset read data from the bank in response to the data thinning instruction.