JPH0530308A - Picture processor - Google Patents

Abstract

PURPOSE:To attain a continuous operation with a small capacity memory and to reduce the cost by outputting a read image data to a picture recording section synchronously with the picture read section from a buffer memory before the buffer memory is filled in a read image data at a copying operation. CONSTITUTION:After an image data form a picture read section 1 is written in a buffer memory 4 via a buffer memory control circuit 3 in the copy operation, the data is outputted to a picture recording section 2 via the control circuit 3. In this case, before the quantity of the image data from the read section 1 sent continuously exceeds the capacity of the buffer memory 4, the operation of the recording section 2 is started. The read section 1 and the recording section 2 are operated synchronizingly. Thus, even the buffer memory with a small capacity can make copying continuously to reduce the cost of a processor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus having a buffer memory for storing image data, the buffer memory having a capacity smaller than that of a page memory, and continuously operating an image reading section and an image recording section.

[0002]

2. Description of the Related Art An image processing apparatus is equipped with a buffer memory for temporarily storing image data read by an image reading unit and temporarily storing image data to be output to an image recording unit. Was there. However, the capacity of this buffer memory was not large enough to store the image data of one page of the document.

FIG. 5 is a diagram comparing the capacities of the page memory and the buffer memory. In FIG. 5, 6 is a page memory, 4 is a buffer memory, D _P is a page memory capacity, and D _B is a buffer memory capacity. The page memory capacity D _P is sufficient to store the image data of one page of the document, while the buffer memory capacity D _P
B has a capacity that can store a very small part of image data for one page.

Since the buffer memory was installed, when reading from the image reading unit, the operation of the image reading unit is once stopped when the image data is read up to the capacity of the buffer memory. Then, after reading the image data from the buffer memory, the operation of the image reading unit is restarted to read new image data. Therefore, the image reading unit performs an intermittent operation.

If the image data is read without stopping, the image data that has been read and has not been used yet will be erased, and the data will be written in the mark. However, this means that the image data that has been read is lost. Become.

When outputting to the image recording unit, the image data is output to the image recording unit when the image data has been written up to the capacity of the buffer memory, and the image recording unit is temporarily stopped after the output. Then, after new image data is written in the buffer memory, the operation of the image recording unit is restarted. Therefore, the image recording unit also operates intermittently. If the image recording unit is not stopped, the buffer memory will become empty in the middle of the page and the image data to be printed will disappear, resulting in a blank portion.

In the image processing apparatus described above, the image reading unit,
The image recording unit has to operate intermittently, which increases the operation time. Therefore, there is provided an image processing apparatus that is equipped with a page memory instead of the buffer memory and can continuously operate the image reading unit and the image recording unit. Since the page memory has a sufficient capacity, it can be continuously read without being stopped in the middle of the page when being read by the image reading section, and when the image recording section is outputting, the image recording section can be read. It can be operated continuously without stopping in the middle of.

[0008]

However, since the page memory requires a large number of memory elements, mounting the page memory is expensive. Therefore, there is a strong demand to reduce the capacity and cost. However, on the other hand, there is also a demand for maintaining that the image reading unit and the image recording unit continuously operate instead of intermittent operation.

In order to meet both of these requirements,
The image data storage memory must be a buffer memory having a smaller capacity than the page memory, while the image reading unit and the image recording unit must be an image processing device that operates continuously.

An object of the present invention is to develop a control method necessary for performing the above operation.

[0011]

In order to solve the above problems, in the image processing apparatus of the present invention, an image reading section and an image recording section that operate continuously and a capacity that cannot store image data for one page of a document are provided. In an image processing apparatus having a buffer memory, during a copy operation, after the image reading unit starts reading, the image data input from the reading is synchronized with the image reading unit from the buffer memory before the buffer memory is filled. It is decided to start output to the image recording unit that continuously operates.

[0012]

[Operation] To reduce the cost, the capacity of the buffer memory mounted in the present invention is set smaller than the capacity of the page memory. However, as the image reading unit and the image recording unit, those that continuously operate are used.

When a copying operation is performed in such an image processing apparatus, when the image reading unit that continuously operates starts reading, the image data is continuously input to the buffer memory without interruption until the one-page original is finished. on the other hand,
Before the buffer memory is filled with image data, recording is started in the image recording unit that continuously operates in synchronization with the image reading unit. As a result, the image data is continuously read from the buffer memory, so that the image data for one page can be continuously sent without filling the buffer memory.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a diagram showing a portion related to the present invention in the configuration of the image processing apparatus. In FIG. 1, reference numeral 1 denotes an image reading unit (which may be abbreviated as “IIT” in the present specification and drawings: Image Input Terminal), and 2 denotes image recording unit (abbreviated as “IOT” in the present specification and drawings). There is also: Image
Out-put Terminal), 3 is a buffer memory control circuit, 4
Is a buffer memory, and 5 is a CPU (central processing unit).

The buffer memory control circuit 3 controls the operations of the image reading section 1, the image recording section 2 and the buffer memory 4 while receiving a command from the CPU 5. When the image processing apparatus is made to perform the copy operation, the image data read from the image reading unit 1 is once written to the buffer memory 4 via the buffer memory control circuit 3. Then, the image data written in the buffer memory 4 is output to the image recording unit 2 via the buffer memory control circuit 3. The buffer memory 4 is used as a ring buffer by changing the order of addresses to the first address after the last address.

FIG. 2 is a diagram showing how image data is stored in the buffer memory. The dotted portion indicates a storage portion (memory use portion) of image data which has been read by the image reading unit 1 but has not yet been output to the image recording unit 2. D _R is the memory usage, and D _B is the buffer memory capacity.

In the present invention, the image reading unit 1 is assumed to operate continuously, so the image reading unit 1 continuously sends image data to the buffer memory 4. In order to avoid that the amount of image data to be read exceeds the capacity of the buffer memory 4 and disappears, in the present invention, the memory usage D of the image data read from the image reading unit 1 is used.
The operation of the image recording unit 2 is started before _R reaches the buffer memory capacity D _B. Image reading unit 1 and image recording unit 2
Since they are operated in synchronization with each other, the reading from the buffer memory 4 is performed at the same speed as the reading, and the image data to be read does not overflow from the buffer memory 4.

The above operation will be described in more detail with reference to FIGS. FIG. 3 is a flow chart for explaining the copy operation according to the present invention, and FIG. 4 is a signal waveform diagram during the copy operation according to the present invention.

FIG. 4A shows changes in the reading speed of the image reading section 1. When you start the image reading unit 1, the reading speed gradually increases to reach a predetermined reading speed V _R. The actual reading of the document is performed after the predetermined reading speed V _R is reached. The page sync signal is a signal output corresponding to one page, and in FIGS. 4B and 4E, the portion where the signal waveform is high corresponds to a certain page.

A description will be given below according to the flow chart of FIG. Step 1 ... Issue a feed command for moving the recording paper to a predetermined position to the image recording unit (IOT) 2. Step 2 ... Image recording unit 2 in response to the feed command
At, a signal for driving the recording paper is issued. This is the sheet drive signal in FIG. 4D, and the movement is started when it goes high at time t ₁ .

Step 3: The recording paper has to be set at a predetermined position (Reg position) prior to the start of recording in the image recording section 2, but it is checked whether or not the recording paper has moved to that position. . Step 4 ... When the predetermined position is reached, the recording paper is stopped. Although this stop is performed at time t ₂ in FIG. 4,
It can be known from the fact that the waveform of FIG. 4D is made low at time t ₂ .

Step 5: When the recording paper reaches a predetermined position, a start command is issued to the image reading section (IIT) 1. Therefore, as shown in FIG.
The reading speed of is gradually increased from time t ₂ . Step 6 ... The image reading unit 1 reads the original document after the reading speed reaches a predetermined reading speed V _R.
The recording paper to be printed is started to move a little before that. The movement is started in response to a signal called a pre-page synchronization signal output from the image reading unit 1. It is checked whether or not the pre-page synchronization signal is output. In FIG. 4, as can be seen from the waveform of FIG. 4C, it is emitted at time t ₃ .

Step 7 ... When the pre-page synchronizing signal is issued, a start command is issued to the image recording unit (IOT) 2. Step 8: The recording paper that has been brought to the specified position
You can start moving again. This is shown by the waveform diagram of FIG. 4D rising to high at time t ₃ .

Step 9 ... It is checked whether a page synchronization signal is output from the image reading section (IIT) 1. The page synchronization signal, the reading speed of the image reading portion 1 reaches a predetermined reading speed V _R, issued after becoming good condition performs reading of the document. In FIG. 4, time t ₄
Has been issued in. The waveform in FIG. 4B is at time t ₄
It is shown by changing to high at. Time t
Assuming that the time from ₃ to time t ₄ is T ₀ , the pre-page synchronization signal (FIG. 4C) is earlier than the page synchronization signal of the image reading unit 1 (FIG. 4B) by the time T _0. (Pre) It has been issued.

Step 10 ... When the page synchronizing signal is output from the image reading section 1, the reading of the original is started and the image data is input to the buffer memory 4. Step 11 ... It is checked whether a page synchronization signal is output from the image recording unit (IOT) 2. In FIG. 4, time t
It is issued at ₅ , which is shown by the waveform being high in Figure 4 (e).

Step 12: If the page synchronizing signal is output from the image recording unit 2, the image data is output from the buffer memory 4 to the image recording unit 2. Time T from the time t _{4 when the} image data is started to be input to the buffer memory 4 to the time t ₅ when the output from the buffer memory 4 is started.
_The amount of image data input during _{1 is} the amount accumulated in the buffer memory 4 (see the memory usage amount D _{R in} FIG. 2), but it is necessary to prevent this from exceeding the buffer memory capacity D _B. Therefore, the maximum allowable value of time T ₁ is
This is the time required to input the image data until the buffer memory capacity D _B becomes full. In the present invention, the page synchronization signal (FIG. 4 (e)) of the image recording unit 2 is controlled to be issued before the time of the maximum allowable value has elapsed.

Step 13 ... It is checked whether or not one page is finished, and if it is not finished, the procedure returns to Step 8. If the page sync signal of the image reading unit 1 goes low at time t ₆ , the page sync signal of the image recording unit 2 goes low at time t ₇ later than that. The delay time is the same time that it was delayed when it went high.

[0028]

As described above, according to the present invention, a buffer memory having a smaller capacity than the page memory is mounted as a memory for storing image data, and the image reading unit and the image recording unit are operated continuously. When the copying operation is performed by the processing device, the copying operation can be continuously performed without pausing in the middle of the page.

[Brief description of drawings]

FIG. 1 is a diagram showing a portion related to the present invention in a configuration of an image processing apparatus.

FIG. 2 is a diagram showing how image data is stored in a buffer memory.

FIG. 3 is a flowchart illustrating a copy operation according to the present invention.

FIG. 4 is a signal waveform diagram during a copy operation according to the present invention.

FIG. 5 is a diagram comparing the capacities of a page memory and a buffer memory.

[Explanation of symbols]

1 ... Image reading unit, 2 ... Image recording unit, 3 ... Buffer memory control circuit, 4 ... Buffer memory, 5 ... CPU, 6 ... Page memory, D _P ... Page memory capacity, D _B ... Buffer memory capacity, D _R ... memory usage, V _R ... predetermined reading speed

Claims (1)

Claim: What is claimed is: 1. An image processing apparatus comprising: an image reading unit and an image recording unit that operate continuously; and a buffer memory having a capacity that cannot store image data for one page of a document. Occasionally, after the image reading unit starts reading, output from the buffer memory to the image recording unit that continuously operates in synchronization with the image reading unit is started before the buffer memory is filled with image data input by reading. An image processing apparatus characterized by the above.