JPH0486063A - Recording method for image forming device - Google Patents

Abstract

PURPOSE:To compose the device of a buffer memory with small storage capacity by fixing the amount of a data, which is recorded by a recording head per unit time, at a constant value. CONSTITUTION:Since an electronic equipment transfers the fixed length of recorded data, a value calculated by adding time measurement data counted every time is in relation proportional to the amount of recorded data transferred during the adding period. Then, a period is calculated by an arithmetical method so that the added result of the time measurement data can be storage capacity C of the buffer memory, and a longest period tau is calculated. Then, receiving and transmitting operations are executed through the buffer memory while defining a data amount S per unit time calculated by dividing the storage capacity C with the period tau as the data reception amount per unit time and the recorded data amount per unit time. In this way, the amount of data recorded by the recording head per unit time is fixed at the constant value S. Thus, the storage capacity of the memory for temporarily storing recorded data transferred from the electronic equipment can be reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a recording device for an image forming apparatus such as a color printer that performs printing or image printing based on print data or image data transferred from an electronic device. Regarding the method.

[Conventional technology]

Dot printers, thermal printing devices, and photosensitive printers that connect to the data output terminals of personal computers, electronic imaging devices, etc., and print characters or images on recording media such as recording paper based on the data transferred from these electronic devices. An image forming apparatus such as a type printing apparatus will be described as a conventional example.

Since electronic devices transfer print data and image data to the image forming apparatus during processing according to various internal operating conditions, interrupt processing, etc., the transfer speed (period) of each data is not constant. Therefore, in order to reliably receive the data transferred from the electronic device, the image forming apparatus is provided with a handshake function, for example, to synchronize with the data transfer of the electronic device.

Then, by supplying the data received by the image forming apparatus to the recording head, printing or image printing (hereinafter, printing or image printing is referred to as recording) is performed.

Here, according to the recorded data transferred from the electronic device,
In order to ensure reliable printing by the print head of an image forming apparatus, the following method has been adopted.

The first method is to directly control the drive of the recording head of the image forming apparatus in synchronization with and following the data transfer timing from the electronic device.

The second method is to find out in advance the longest data transfer cycle of the electronic device, in other words, the slowest data transfer speed, and synchronize to this longest data transfer cycle using a handshake function with the image forming device or the electronic device. Each recording data is received in each period, and the recording head is caused to perform a recording operation one by one every time the recording data is received in each period. According to this second method,
Data transfer by the electronic device and recording by the image forming apparatus can be performed in the same cycle.

The third method is when printing one frame of image on recording paper such as Japan Standard 84 edition or A4 edition, the memory is large enough to store the recording data corresponding to the entire area of these recording papers. A frame memory with a large capacity is built into the image forming apparatus, and first, all recorded data corresponding to one frame image is transferred from the electronic device to the frame memory, and after this data transfer is completed, the recording head is used to record data at a predetermined period. Recording is performed after reading each recording data from the frame memory in accordance with the recording timing of . According to this third method, there is no need to synchronize the timing of receiving recording data from the electronic device with the recording timing of the image forming apparatus, making it easy to control the details.

[Invention or problem to be solved]

However, in conventional image forming apparatuses that adopt the first method described above, the drive speed of the recording head is directly related to the data transfer cycle of the electronic device, so it is difficult to record at a constant speed. Therefore, a mechanical and electrical drive mechanism will be required to drive and control the recording head so that it can correspond to all recording speeds.
It is extremely difficult to realize this, and there have been problems of uneven printing, uneven printing, misaligned printing, and misalignment on the recording medium.

In the conventional example that adopts the second method, it is possible to record at a constant speed, so it is difficult to achieve high quality recording without uneven printing or uneven printing. , the waiting time for receiving each recorded data from the electronic device is longer.
The problem was that the recording speed was extremely slow.

Conventional methods that adopt the third method require a frame memory with a huge storage capacity, resulting in high costs and problems such as being unable to be applied to low-cost image forming apparatuses. .

The present invention has been made in view of the problems of the prior art, and is capable of reducing the storage capacity of a memory that temporarily stores recorded data transferred from electronic devices, and that is capable of high-speed and high-performance processing. An object of the present invention is to provide an image recording device that can realize high quality recording.

[Means to solve the problem]

In order to achieve such an object, the present invention first receives recorded data such as printing data and image printing data transferred from an electronic device, and records on a recording medium based on this recorded data. Targets recording methods of image forming apparatuses.

First, regarding the recording method of such an image forming apparatus,
Before starting the recording operation, determine the maximum length of time for at least one frame of recorded data until the sum of multiple pieces of consecutive recorded data transferred from the electronic device each time reaches a predetermined storage capacity of the buffer memory. In addition to measuring time, the amount of data per unit time is calculated by dividing the storage capacity by the longest time, and when recording, this amount of data is calculated as the amount of data received from the electronic device per unit time. The recording data is input to the sofa memory and the amount of data is recorded as the recording amount per unit time. Recording data is supplied to the recording head via the sofa memory.

Further, the present invention will be explained in detail based on FIGS. 1 and 2.

When data transfer is performed without performing any synchronization control on an electronic device, each transfer cycle varies.

Furthermore, if this fluctuation is replaced with the relationship between the amount of data transferred per unit time, it will fluctuate as shown in FIG. 1, for example. Note that T in FIG. 1 is the point in time when, for example, the transfer of one frame worth of recording data is completed.

Therefore, before performing an actual recording operation, the electronic device is made to transfer at least one frame of recorded data, and the transfer cycle between the recorded data transferred each time is measured.

Since electronic equipment transfers recorded data of a fixed length, the value obtained by adding the clocked data each time is proportional to the amount of recorded data transferred during the addition period. , calculates by a mathematical method a period such that the result of the addition operation of the clock data becomes the storage capacity C of the buffer memory, and detects the longest period τ from among the calculation results. For example, in FIG. 1, Δt, Δt
〈If the relationship is Δt2, Δt is the longest period τ
shall be.

Then, as shown by the solid line in FIG. 2, the storage capacity iC is changed over the period τ
The reception and recording operations are performed via the buffer memory using the amount of data S per unit time obtained by dividing by S as the amount of data received per unit time and the amount of recorded data per unit time.

Furthermore, numerically speaking, since electronic equipment transfers recorded data of a fixed length, if each recorded data has a fixed bit length, the handshake function can be performed in synchronization with the period Δτ determined by the calculation of L=S. The record data may be received and recorded by, for example.

[Effect]

According to the recording method of the present invention based on such a principle, the second
As shown by the solid line in the figure, since the amount of data recorded per unit time by the recording head can be fixed at a constant value S (== fixed), recording unevenness caused by conventional recording speed fluctuations can be significantly reduced. I can do it.

Also, if recorded data equal to the set recorded data amount S per unit time is received every unit time based on this principle, the amount of data temporarily held in the buffer memory will be equal to the preset storage capacity of the buffer memory. , so there is no loss of recording, and the buffer memory has an extremely small storage capacity compared to the conventional frame memory that stores all of one frame image. That's enough.

Furthermore, the present invention does not operate in synchronization with the lowest data transfer speed of an electronic device as in conventional examples, but instead finds conditions for performing data transfer at the highest speed within the storage capacity of a buffer memory provided in advance. Since it operates under these conditions, it is possible to record at a higher speed. for example,
Point P in Fig. 1 is the lowest data transfer speed of the electronic device, and when recording is performed at the amount of recorded data S' per unit time corresponding to this speed, the dot-dash line in Fig. 2 As shown in the figure, it takes a long time to complete the recording of one frame (
However, according to the present invention, recording can be completed in a shorter time, for example, at time T' in FIG. 2.

〔Example〕

An embodiment of an image forming apparatus to which the recording method of the present invention is applied will be described below with reference to the drawings.

First, the configuration will be explained based on FIG. 3. The part shown within the dashed line in the figure is an image forming apparatus l such as a color printer. 2 is a recording head that records on a recording medium such as recording paper, and 3 is a recording head that records by moving the recording head 2 relative to the storage medium PP in the main scanning direction X and the sub-scanning direction Y, as shown in FIG. 4 is a buffer memory that temporarily stores recording data to be supplied to the recording head 2, 5 is a switch circuit having a switching function between two contacts A and B, and 6 is a circuit that connects various external electronic devices. This is an interface circuit for connection.

By connecting the interface circuit 6 to an interface circuit 7 built into an external electronic device,
A record monitor D transferred from a storage device 8 such as a database in an electronic device is received. Note that 9 is a display device of the electronic device, and 10 is a main body portion that can be used to instruct various operations from a keyboard.

Further, reference numeral 11 denotes a time measuring section, which measures the transfer speed (period) between each recording data transferred from the electronic device via the interface 6 when the switch circuit 5 is switched and connected to the contact A. Note that when the switch circuit 5 switches to the contact B side, each recording data transferred from the electronic device is supplied to the buffer memory 4.

Reference numeral 12 denotes a control unit that controls the overall operation of the image forming apparatus l, which receives clock data F measured by the clock unit 11, and sets the optimum recording timing from the clock data F, as will be described later, to control the drive mechanism 3. It also controls the reception timing of the interface 6, the read/write timing of the buffer memory 4, the switching timing of the switch circuit 5, etc.

Next, the operation of the image forming apparatus having such a configuration will be explained according to the flowchart shown in FIG. In this embodiment, it is assumed that the electronic device transfers fixed length recording data every time.

When the power is turned on and an external electronic device instructs the image recording device to start recording, in step +00, the control unit 1
2 or switches the switch circuit 5 to the contact A side, and supplies the recorded data transferred via the interface 6.7 to the timer section II.

Next, in step 110, the timer 11 measures each transfer cycle of the recorded data for each recording dot, and each time it is measured, the timer data F indicating each transfer cycle is sent to the controller 12.
supply to Furthermore, each time the control unit 12 receives the time measurement data F, it adds up a plurality of past time measurement data from the latest time measurement data, and calculates a period τ' corresponding to the storage capacity C of the buffer memory 4 based on the addition result. do. That is, if the latest counting data is F-0 and the i previous counting data is F, then the timing data F-, -F- when [B is the bit length of each recorded data] , is the period τ°.

Then, a storage area is provided in advance in the control unit 12 to store the data of the period τ', and each time the latest period τ' is calculated, it is replaced with data indicating the longest period, and finally,
For example, the longest period τ of recording data for one or more frames set in advance is determined.

When the above-mentioned time measurement process for the recording data for a predetermined frame is completed, next, in step 120, the cycle Δτ (hereinafter referred to as synchronization cycle) for the recording head 2 to perform recording is calculated. That is, when each recording data has a fixed bit length, the calculation is performed by the following calculation: Δτ=(L×τ)÷C.

Next, in step 130, the switch circuit 5 is switched to the contact B side, and furthermore, an instruction is given to the external electronic device to transfer the recorded data from the beginning again.

Next, in step 140, when the recorded data is transferred, the control unit 12 performs timing control using a handshake function or the like so that each recorded data is transferred to and from the interface 6.7 at a synchronization period Δτ, and further ,
The buffer memory 4 is caused to perform read/write operations in synchronization with this synchronization period Δτ, and the driving mechanism 3 is timing-controlled so that the recording head 2 records each dot at each synchronization period Δτ.

Then, recording is performed at a constant synchronization period Δτ until data transfer from the electronic device is completed, and upon completion, the recording operation is stopped.

Note that the timing process to determine the synchronization period Δτ is not performed for all frame images to be recorded;
First, it is performed on recording data corresponding to at least one or more relatively small frame images.

By performing the timekeeping process in this manner, it is possible to obtain an optimal synchronization period that does not cause recording unevenness, and the storage capacity of the buffer memory 4 can be kept relatively small.

Next, another embodiment will be described.

First, the configuration of the image recording apparatus will be explained based on FIG. Note that the same or corresponding parts as in FIG. 3 are indicated by the same reference numerals. To explain the difference between FIG. 5 and FIG. 3, the control unit 12 includes a memory 14 for storing data Δτ1 to Δτ of j pieces of synchronization period calculated in the past (j is a natural number at the appropriate time). It is equipped with Further, as shown in FIG. 6, the memory 14 sequentially stores data Δτ of the oldest synchronization cycle to data Δτ of the latest synchronization cycle, and further inputs data of the latest synchronization cycle. The data is sequentially updated by discarding the data Δτ of the oldest synchronization cycle and rearranging them in the oldest order.

Next, the operation of the image forming apparatus shown in FIG. 5 will be explained based on the flowchart shown in FIG.

When the power is turned on and an external electronic device instructs the image recording device to start recording, in step 150, the control unit 1
According to the instructions in step 2, set the value to 1 in the specific register in the clock section II.
, and sets itself to receive recording data corresponding to the th (initially, the 1st) frame image from the external electronic device.

Next, in step 160, the control unit 12 or the switch circuit 5 is switched to the contact A side, and the interface 6.
The recording data transferred via the clock section 7 is supplied to the clock section 11.

Next, in step 170, the timer 11 measures each transfer cycle of the recorded data for each recording dot, and each time it measures, the timer data F indicating each transfer cycle is sent to the controller 12.
supply to Furthermore, each time the control unit 12 receives the time measurement data F, it adds up a plurality of past time measurement data from the latest time measurement data, and calculates a period τ° during which the addition result corresponds to the storage capacity C of the buffer memory 4. do. That is, if the latest counting data is F-0 and the i previous counting data is F-, then the timing data F-I-F- [where B is the bit length of each recorded data] , is the period τ′.

Then, a storage area is provided in advance in the control unit 12 to store the data of the period τ', and each time the latest period τ' is calculated, it is replaced with data indicating the longest period, and finally,
For example, the longest period τ of recording data for one or more frames set in advance is determined.

When the time measurement process for the recorded data for a predetermined frame is completed, next, in step 180, the cycle Δτ' is calculated by calculating the following equation. That is, when each recording data has a fixed bit length, the following calculation is performed: Δτ'=(LXτ)÷C.

Next, in step 180, the optimum synchronization period Δτ is determined by averaging the j pieces of data Δτ1 to Δτ1 stored in the memo January 4 and the data Δτ′. Note that the contents of storage areas that have not yet been stored in the memory 14 are not applied to this averaging calculation. After this calculation, the oldest data Δτ1 in the memory 14 is discarded, and the data with the latest synchronization period Δτ is stored in the memory 14 as the latest data Δτ1.

Next, in step 190, the switch circuit 5 is switched to the contact B side, and furthermore, the external electronic device is instructed to transfer the recorded data corresponding to the th frame again.

Next, in step 200, when the recorded data is transferred, the control unit 12 performs timing control using a hunt shake function or the like so that each recorded data is transferred to and from the interface 6.7 at the optimum synchronization period Δτ. Furthermore, in synchronization with this cycle Δτ, the buffer memory 4 is caused to perform read/write operations, and furthermore, the drive mechanism 3 is timing-controlled so that the recording head 2 performs recording every cycle Δτ. Then, recording is performed at the above-mentioned cycle Δτ until recording for a predetermined m frames is completed.

Next, in step 210, when it is determined that recording of m frames has been completed, the process moves to step 220, and the next m frames are recorded by replacing the value of k with +m+1. Set.

Then, in step 230, when it is determined that the data transfer from the electronic device has been completed, the recording operation is stopped;
If you have not yet completed all recordings, proceed to step 1.
The process moves to step 60, and the same process is repeated for the record data corresponding to the +m+1th frame.

In this way, this embodiment has a learning function that determines the optimal synchronization cycle by performing an arithmetic average calculation of the latest synchronization cycle and the old synchronization cycle for each appropriate frame. can be set.

In this embodiment, a new synchronization cycle is set each time the power is turned on, or the data stored in the memory 14 is not erased even when the power is turned off, and the recording is continued in the next recording operation. When setting the cycle, it may be used as data of the old recording cycle.

〔Effect of the invention〕

As explained above, according to the present invention, the amount of data recorded by the recording head per unit time can be fixed at a constant value, so recording unevenness caused by conventional recording speed fluctuations can be significantly reduced. I can do it.

Furthermore, if recorded data equal to the amount of recorded data per unit time set according to the present invention is received every unit time,
The amount of data temporarily stored in the buffer memory does not exceed the preset storage capacity of the buffer memory, so there is no loss of recording, and all one frame image can be stored as in the case of conventional methods. Compared to providing a frame memory for the data processing, it is sufficient to provide a buffer memory with an extremely small storage capacity.

Furthermore, the present invention does not operate in synchronization with the lowest data transfer speed of an electronic device as in conventional examples, but instead finds conditions for performing data transfer at the highest speed within the storage capacity of a buffer memory provided in advance. Since it operates under these conditions, it is possible to record at a higher speed.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams for explaining the present invention in detail; FIG. 3 is an explanatory diagram showing the configuration of an image forming apparatus according to an embodiment; and FIG. FIG. 5 is a flowchart for explaining the operation of the embodiment; FIG. 6 is an explanatory diagram showing the configuration of an image forming apparatus according to another embodiment; FIG. FIG. 6 is an explanatory diagram for explaining the functions of the memory in FIG. 6, and FIG. 8 is a flowchart for explaining the operation of the embodiment shown in FIG. Symbols in the figure: 1: Image forming device 2: Recording head 3, drive mechanism 4; Buffer memory 5: Switch circuit 6.7: Interface 8: Recording device 0; External electronic device 1: Timing section 2, Control section 3: Display section 4 memory

Claims (1)

[Claims] In a recording method for an image forming apparatus that receives recording data transferred from an electronic device and records on a recording medium based on the recorded data, at least one frame is recorded before starting a recording operation. The longest time it takes for the sum of a plurality of pieces of consecutive recorded data that the electronic device transfers each time to reach a predetermined storage capacity of the buffer memory, and The amount of data per unit time is calculated by dividing by time, and when recording, this amount of data is input to the buffer memory with a predetermined storage capacity as the amount of data received per unit time from the electronic device, and the amount of data is 1. A printing method for an image forming apparatus, characterized in that printing is performed at a constant speed by supplying print data to the print head via the buffer memory, with the print amount per unit time by the print head.