JPH0833725B2 - Image memory controller - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image memory control device, and more particularly, to image memory control in which a writing direction to a bitmap memory or a reading direction from a bitmap memory is variable. It relates to the device.

(Prior Art) A conventional printer, such as a laser printer, which receives a code as control information from an external host system and prints it out as a visible image has a configuration as shown in FIG.

As shown in the drawing, the printer is mainly composed of an image supply device A, a recording section B and a panel C. Control information is input to the image supply device A in the form of a code from an external host system such as a personal computer or a LAN. Also, switch information S / W is input from panel c.

The image supply device A includes a CPU, a program ROM,
It has a controller unit including a RAM and the like, a character pattern ROM in which character patterns are accumulated, and a bit map memory in which the character information read from the character pattern ROM is temporarily accumulated. On the other hand, the recording unit B is a laser beam modulator that modulates a laser beam according to the video information of characters read from the bit map memory of the image supply device A, the modulated laser beam is irradiated, and the laser beam modulator is statically irradiated on the laser beam modulator. It includes a photosensitive drum that forms an electrostatic latent image, a device that develops the electrostatic latent image, and transfers and fixes it on the conveyed paper.

(Problems to be Solved by the Invention) Now, in the printer having the above configuration,
Consider the case where four types of printing are performed as shown in FIG. That is, portrait portrait writing as shown in FIG. 9A, landscape landscape writing as shown in FIG. 7B, landscape landscape writing as shown in FIG. Considering the four types of portrait horizontal writing, the angle of rotation of the characters ABCD ... is 0 ° in the case of landscape vertical writing, but −90 ° in the case of portrait vertical writing and landscape horizontal writing. In the case of portrait horizontal writing, it is + 180 °. The paper feeding direction is the arrow direction shown.

Therefore, if you try to perform the above four types of printing with a conventional printer, the rotation angle of the characters will be 0 ° and -90 °.
And the three types of characters ABCD of + 180 ° must be placed in the character pattern ROM in the image supply device A, which causes a problem that the capacity of the character pattern ROM becomes large.
Further, this causes a problem that the cost of the device increases.

An object of the present invention is to eliminate at least the above problems of the conventional apparatus, and to store at least the character having a rotation angle of 0 ° in the character pattern ROM to perform at least the four types of printing. An image memory control device is provided.

(Means and Actions for Solving Problems) In order to solve the above problems, the present invention reads a character pattern from a character pattern ROM and stores it in a bitmap memory, and scans each scanning line from the bitmap memory. In the image memory control device of the device for supplying the digital image signal to the recording device or the display device, a selector with a register for setting a start address to which the selected character pattern is transferred, + M, -M, -1 and +1 The addition value selector that stores the addition value of, and the addition value selector from which a value corresponding to the rotation angle of the character pattern is selected, the addition target selector to which the output of the selector with register is input, the addition target selector, and the addition value An adder for adding the outputs of the selector, a memory address output register connected to the adder, and an output of the adder for the register And a means for connecting the output of the memory address output register to the selector to be added, and a start address set in the selector with register and a value of M set in the addition value selector. The feature is that the character pattern is rotated by a predetermined angle by being given.

(Example) Below, this invention is demonstrated in detail with reference to drawings.

FIG. 2 shows a block diagram of an example of an image supply device to which the present invention is applied.

In the figure, reference numeral 21 is an interface section for receiving a code from an external personal computer or the like in accordance with the RS232C standard, and 22 is a controller section (CPU, ROM, RAM, PIO) for system control of an image supply apparatus incorporating the present invention.
, 23 is a character pattern ROM (character generation memory) that stores character patterns and pixel patterns, 2
4 is a bit map memory, 25 is a timing controller for synchronizing the big stream with the recording section B, 26 is an image to be written to the bit map memory 24 while referring to the character pattern ROM 23 in response to an instruction from the controller section 22. Is an image handler that generates A memory controller 27 controls the access timing to the bit map memory 24.

Next, FIG. 1 shows an embodiment of the memory controller 27 which is an essential part of the present invention.

In the figure, 1 is a selector with a register (for example, 74HC
298 can be used), 3 is a selector to be added (for example, 74HC157), 4 is a data bus input register (for example, 74HC574), and 5 is an addition value selector (for example, 74HCT54).
1), 6 is an adder (for example, 74HC283), 7 is a bitmap memory address output register (for example, 74HC574),
Reference numeral 8 represents an N-ary subtraction counter, and 9 represents a K-ary subtraction counter.

When the initial data set, the selector with register 1
The initial data WAS input from the terminal D is stored in the register, and the data input from the terminal C is stored in the register by the zero output output from the N-ary subtraction counter 8. The augend selector 3 selects the terminal B when at least one of the count values of the K-adic counter 9 and the N-adic subtraction counter 8 is 0, and both the K-adic counter 9 and the N-adic counter 8 indicate a count value other than 0. Sometimes, terminal A is selected.

Further, the addition value selector 5 selects either one of +1 and −1 and one of + M and −M, that is, a combination of ± 1 and ± M by a specification signal I applied from the outside. At the same time, depending on the count value of the N-ary subtraction counter 8, it is selected whether to select a set of +1 and −1 or a set of + M and −M. Here, M represents the size of one side of the bitmap memory, that is, the number of bits of the memory width in the direction in which the addresses of the bitmap memory are continuously assigned.

Specifically, the count value of the N-ary subtraction counter 8 is N-
When the count value is 0, the group of + M and -M is selected, and when the count value is 0, the group of +1 and -1 is selected.

The N-ary subtraction counter 8 counts the pulse output from the bit map memory address output register 7 at the time of data setting as a clock. On the other hand, the K-adic subtraction counter 9 counts the number of zero outputs output from the N-adic subtraction counter 8 by the clock output from the address output register 7. When the K-adic subtraction counter 9 outputs zero, the operations of the N- and K-adic subtraction counters 8 and 9 are stopped.

Next, using the apparatus of the above-mentioned embodiment, the character pattern
From the character with a rotation angle of 0 ° stored in ROM13,
The operation of performing the above-described four types of printing will be described.

Now, the character pattern stored in the character pattern ROM 23 has a width of 20 dots, as shown in FIG.
It is assumed that the height is 30 dots, and that it is stored in address 1 to 600 in order.

Next, from the character pattern ROM 23 to the image handler 26
The bitmap memory 24 that stores the video information of the character pattern sent via the has a memory capacity of, for example, 10 million words, and an image area corresponding to the image size of the paper to be printed is formed in it. To be done.

In order to simplify the description, the description will proceed below assuming that 1 word = 1 dot with a resolution of 10 dots per mm. If an image area having a long side of 300 mm and a short side of 200 mm as shown in FIG. 4 is formed in the bit map memory 24, 6 million words are used in this area. In addition, when character information is read from the image area, that is, when printing is performed, 2000
It is assumed that the image area is sequentially read from the image area.

First, the operation of forming in the bitmap memory 14 the characters rotated by −90 ° for portrait portrait writing and landscape landscape writing shown in FIGS. 12A and 12B will be described.

Now, the character "A" shown in FIG. 5 (b) is read from the character pattern ROM 23 in the order of addresses 1, 2, ..., 600, and stored in the bitmap memory shown in FIG. 5 (a). Considering the case of being transferred, if the pattern data at the address and the address of the bit map memory have the relation shown in Table 1, the character A is rotated by -90 ° and stored in the pit map memory. Will be done.

Next, the reason why the above operation can be performed by using the circuit shown in the block diagram of FIG. 1 will be described with reference to FIG.

First, when the initial data WAS (start address) = 75000 input from the D terminal is set in the selector with register 1, since the K-adic subtraction counter is 0 at this time, the initial data 75000 is stored in the selector with register 1 and It is sent to the adder 6 and the bit map memory address output register 7 via the augend selector 3.

Then, the initial data 75000 is temporarily stored in the register 7. The data stored in the register 7 is sent to the bit map memory 24 of FIG. 2 as an address signal.

When the pattern data of FIG. 5B is sent to the bit map memory 24, this data is stored at the address 75000 on the bit map memory 24.

Next, 2000 is input as the initial data M, and this value is set in the data bus input register 4. As a result,
M in the addition value selector 5 becomes M = 2000. The addition value selector 5 is designated by + M and -1 by the designation signal I. Further, the N-ary subtraction counter 8 is set to the initial value N = 20, and the K-ary subtraction counter 9 is set to the initial value K = 30.

Then, the count value of the K-adic subtraction counter 9 is 30.
Since (= K) and the count value of the N-ary subtraction counter is 29, the selector with register 1 selects the D terminal side,
The augend selector 3 selects the A terminal side. Since 75000 is currently stored in the register 7, this data is sent to the adder 6 through the auged selector 3. On the other hand, in the addition value selector 5, the count value of the N-ary subtraction counter 8 is 19
Since (= N-1), 2000 (= + M) is selected.
Therefore, the adder 6 calculates (75000 + 2000) and sends the calculated value to the register 7. The register 7 temporarily stores this at a predetermined timing and sends it to the bitmap memory 24 as an address signal.

At this time, when the pattern data of FIG. 5 (b) is sent to the bitmap memory 24, this data is stored at address 77000 on the bitmap memory.

When the data 77000 is stored in the register 7, a clock signal is output from the register 7 and the N-ary subtraction counter 8 is decremented by 1. Then, the same operation as described above is performed. When the operation is repeated 19 times, the value in register 7 becomes 79
Data of 000, 81000, ..., 113000 are sequentially stored and updated.

When the register 7 stores the data 113000 and the clock is output from the register 7, the count value of the N-ary subtraction counter 8 becomes 0, and the zero output is output to the K-ary subtraction counter 9. As a result, the count value of the K-adic subtraction counter 9 is decreased by 1 to 29. Therefore, the augend selector 3
Selects the B terminal side, and the selector with register 1 selects the C terminal side. Further, the addition value selector 5 selects -1.

Therefore, the adder 6 calculates the WAS (= 75000) supplied from the selector with register 1 and the data (-1) supplied from the addition value selector 5, and stores the data of (WAS-1) in the register 7. It is sent to the selector with register 1 as well as sent. The data is latched in the selector with register 1.

When the value of (WAS-1) is stored in the register 7, a clock is output from the register 7 and the N-ary subtraction counter 8 returns to the initial value of 19. When the count value of the N-ary subtraction counter 8 becomes 19, the auged selector 3 selects the A side terminal, and the addition value selector 5 selects 2000 (= + M). Thereafter, the same operation as described above is repeated, and the register 7
74999,76999, ..., 112999 is output.

When the data 112999 is stored in the register 7, a clock is output from the register 7 and the N-ary subtraction counter 8 becomes 0. Then, similarly to the above, the augend selector 3 selects the B terminal, while the addition value selector 5 selects -1. Since the selector with register 1 selects the C terminal, the operation output of the adder 6 is (WAS-2) = 74998, which is stored in the register 7.

It will be apparent that when the same operation is repeated thereafter, the bitmap memory addresses in Table 1 are sequentially designated.

The above operation can be summarized as shown in FIG. That is, the first bitmap address is WA
The operation of inputting as S = 75000, and then adding 2000 to this is repeated 19 times, and when this is completed, the operation of subtracting 1 from the WAS is performed.

Then, the operation of adding 2000 to (WAS-1) is repeated 19 times, and when this is finished, 1 is subtracted from (WAS-1). Next, the operation of adding 2000 to (WAS-2) is repeated 19 times.

The above operation is repeated until 30 (WAS-1)
When the process of (WA + 2000) is repeated 19 times, all the patterns of FIG. 5 (b) are moved to the addresses 75000 to 112971 of the bitmap memory of FIG. 5 (a). This means that the character A could be rotated by -90 ° and stored in the bitmap memory.

In the above explanation, one character A was rotated by −90 °, but when ABCD ... continues like a sentence, B,
C, D, ... May be rotated by −90 ° in the same manner as described above.

In this case, the coordinates of the origin are determined in advance by portrait portrait writing or landscape landscape writing, so the start address of each character is determined starting from this origin, and the start address is applied to the circuit of FIG. 1 as the WAS. By doing so, portrait vertical writing or landscape horizontal writing data can be written in the bitmap memory 24.

When reading the data from the bit map memory 24, the data may be read in the order from the smaller address to the larger address as usual.

Next, the operation of this embodiment will be described for the case of performing landscape vertical writing as shown in FIG. 12 (c). In this case, as shown in FIG. 7, a character having an inclination of 0 ° is transferred from the character pattern ROM 23 to the bit map memory 14.

Now, the character "A" shown in FIG. 7 (b) is read from the character pattern ROM in the order of addresses 1, 2, 3, ..., 600, and the bit map shown in FIG. 7 (a). Considering the case of being transferred to the memory, if the pattern data at the address and the address of the bitmap memory have the relationship shown in Table 2, the character A has an inclination of 0 ° and is stored in the bitmap memory. Will be stored in.

In order to operate the embodiment of FIG. 1 so that the correspondence relationship in Table 2 is established, the initial data WAS (start address) input from the D terminal to the selector with register 1 is set to 75000 and input to the input register 4. The value of M to be set is 2000, and + M and +1 may be specified by the signal I specifying the addition value selector 5. Also, the initial values N and K set in the N-ary subtraction counter 8 and the K-ary subtraction counter 9 are set.
May be 20 and 30, respectively, as described above.

When the initial values are set to the above values and the circuit of FIG. 1 is operated, WA = WA as shown in FIG.
The operation of S and WA = WA + 1 is repeated 19 times, then WA
= WAS + 2000, WA = WA + 1 is repeated 19 times. Ultimately, the above operations will be performed 30 times in total.

By this operation, the addresses shown in the bitmap memory address in Table 2 are sequentially stored in the bitmap memory 24.
And the pattern data is transferred from the character pattern ROM 23 to the bitmap memory 24 in synchronism therewith, so that the character A having an inclination of 0 ° can be stored in a predetermined area of the bitmap memory 24.

The above explanation was for the case where the inclination of one letter A was inclined by 0 °, but if ABCD …… continues like a sentence, then B, C,
The processing may be performed by inclining D ,.

In this case, the coordinates of the origin of landscape vertical writing are predetermined, so if the start address WAS of each character is determined from this origin, the character data for landscape vertical writing is stored in the bitmap memory 24.
You can write inside. Then, landscape vertical writing can be performed by reading from the bitmap memory 24 at a normal read address.

Next, the operation of this embodiment will be described for the case of performing portrait horizontal writing shown in FIG. In this case, as shown in FIG. 9, the character A read from the character pattern ROM 23 is rotated by 180 ° and written in the bitmap memory 14.

Now, the character "A" shown in FIG. 7 (b) is read from the character pattern ROM in the order of addresses 1, 2, 3, ..., 600, and the bit map shown in FIG. 7 (a). Considering the case of being transferred to the memory, if the pattern data at the address and the address of the bitmap memory have the relationship shown in Table 3, the character A is rotated by 180 ° and is stored in the bitmap memory. Will be stored in.

In order to operate the embodiment shown in FIG. 1 so that the correspondence relationship in Table 3 is established, the initial data WAS (start address) input from the D terminal to the selector with register 1 is set to 75000 and input to the input register 4. The value of M to be set is 2000, and -M and -1 may be specified by the signal I specifying the addition value selector 5. Also, the initial values N and K set in the N-ary subtraction counter 8 and the K-ary subtraction counter 9 are set.
May be 20 and 30, respectively, as described above.

When the initial values are set to the above values and the circuit of FIG. 1 is operated, as shown in FIG. 10, WA = WA
The operation of S, WA = WA-1 is repeated 19 times, then WA
= WAS-2000, WA = WA-1 is repeated 19 times. Ultimately, the above operations will be performed 30 times in total.

By this operation, the addresses shown in the bitmap memory address in Table 3 are sequentially stored in the bitmap memory 24.
Is output to the bit map memory 24 by transferring the pattern data from the character pattern ROM 23 to the bit map memory 24 in synchronization with this.
Can be stored in a predetermined area.

In the above explanation, one character A was rotated by 180 °, but if ABCD …… continues like a sentence, then B, C, D,
.. may be rotated 180 degrees in the same manner as above.

In the above description, the character read from the character pattern ROM23 is rotated by -90 °, 0 ° and + 180 ° and stored in a predetermined address of the bitmap memory 24. However, the character is read from the character pattern ROM23. It goes without saying that the present embodiment may be applied when the character is stored in the bitmap memory 24 without being subjected to the above-described rotation processing and is read from the bitmap memory 24 to the printer.

Although the above embodiment is an example of printing using a rotated character pattern, the character pattern information may be sent to a display device to monitor whether or not the desired rotation is performed. .

(Effects of the Invention) As is clear from the above description, according to the present invention, the following effects are achieved.

(1) By simply storing a character whose rotation angle is 0 ° in the character pattern ROM, it is possible to store -90 ° and 180
Since the rotated character pattern data can be created, the capacity of the character pattern ROM can be minimized and the cost can be reduced.

(2) Portrait vertical and horizontal writing, and landscape vertical and horizontal printing can be easily performed.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG.
FIG. 3 is a block diagram showing a specific example of the image supply device shown in FIG. 3, FIG. 3 is a diagram showing an example of a character pattern stored in the character pattern ROM 23, and FIG. 4 is an image area formed in a bitmap memory. FIGS. 5 and 6 show an example of transferring a character pattern rotated by −90 ° for portrait vertical writing and landscape horizontal writing to a bitmap memory, and FIGS. 7 and 8 show landscape vertical writing. FIG. 9 and FIG. 10 are explanatory views of transferring a character pattern for portrait horizontal writing to a bitmap memory, and FIG. 11 is a schematic block diagram of a conventional printer. , FIG. 12 is an explanatory diagram of portrait portrait, landscape portrait, landscape portrait portrait, and landscape portrait portrait. 1 ... Selector with register, 3 ... Selector to be added, 5
…… Addition value selector, 6 …… Adder, 7 …… Memory address output register, 8 …… N-ary subtraction counter, 9 …… K
Decimal subtraction counter, 23 …… Character pattern ROM, 24 …… Bit map memory, 27 …… Memory controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-52345 (JP, A) JP-A-61-89051 (JP, A) JP-A-60-144790 (JP, A) JP-A-59- 220855 (JP, A) JP 59-123925 (JP, A) JP 60-232594 (JP, A) JP 58-93095 (JP, A) JP 59-224892 (JP, A)

Claims (1)

[Claims] 1. An image memory device of a device for reading a character pattern from a character pattern ROM, storing the character pattern in a bit map memory, and supplying a digital image signal for each scanning line from the bit map memory to a recording device or a display device. Means for sequentially supplying the start address of each character starting from the desired printing origin among four types of printing of rate vertical, horizontal writing, landscape vertical, and horizontal writing, and a register for sequentially setting the supplied start address And an additional value of + M, -M, -1, and +1 (where M represents the number of bits of the bit map memory width in the direction in which addresses are consecutively added), and the desired value is selected from these. Output of the selector with added value and the value selected according to the rotation angle of the character pattern corresponding to the printing of Connected adder, an adder for adding the outputs of the adder selector and the addition value selector, a memory address output register connected to the adder, and an output of the adder connected to the registered selector And a means for connecting the output of the memory address output register to the augend selector so that desired printing among the four types of printing can be performed. .