JP2000071437A - Ink jet recording apparatus, storage medium, and control table creation method - Google Patents

Abstract

(57) [Summary] [Problem] With a simple configuration, drive control cannot be performed with drive control parameters corresponding to head characteristics. SOLUTION: A control table is created by a neural network means which uses relative speed information on a relative speed between a recording head and a recording medium under specific driving conditions and environmental information on environmental conditions as input information and driving conditions of the recording head as output information. I do.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, a storage medium, and a control table creation method.

[0002]

2. Description of the Related Art An ink jet head used in an ink jet recording apparatus used as an image recording apparatus (image forming apparatus) such as a printer, a facsimile, a copying apparatus, etc. has a nozzle hole for discharging ink droplets and a discharge chamber in which the nozzle hole communicates. (Also referred to as a pressure chamber, a pressurized liquid chamber, a liquid chamber, an ink flow path, etc.) and actuator means (an electromechanical conversion element such as a piezoelectric element,
An electrothermal conversion element such as a heating element, an electrode for generating electrostatic force paired with the diaphragm, etc.), and by driving the actuator element in accordance with an image signal, the ink in the ejection chamber is pressurized to be discharged from the nozzle hole. Ink-on / off, which ejects ink droplets only when recording is necessary
The demand type is the mainstream.

In general, in an ink jet recording apparatus, when environmental conditions such as environmental temperature and environmental humidity change, the ink droplet ejection characteristics of a head, that is, the ink droplet ejection amount and ink droplet ejection speed increase or decrease. The image quality may be degraded.

Therefore, conventionally, as described in JP-A-5-24199, the jetting characteristics are stabilized by keeping the temperature of the head constant,
As described in Japanese Patent Application Laid-Open No. 5-116294 and Japanese Patent Application Laid-Open No. 8-234450, the head is driven by fuzzy control.
As described in Japanese Unexamined Patent Application Publication No. Hei 9-99556, there is known a method and apparatus in which a structural change of a drive circuit or a head responds to a characteristic change.

However, these conventional techniques require extra energy to maintain a constant temperature,
When the configuration of the apparatus becomes complicated or a physical model for obtaining the characteristics of the head is required, complicated experiments and development of the apparatus are indispensable, and the cost increases.

Therefore, Japanese Patent Application Laid-Open No. 6-344571,
JP-A-7-323552 and JP-A-9-16470
As described in Japanese Unexamined Patent Publication No. 2 (2003), as a simpler method, drive control parameters are prepared in the form of a control table, and the control table is referred to based on environmental conditions such as temperature separately measured. Methods and apparatuses for selecting various drive control parameters have been proposed.

[0007]

However, by providing the drive control parameters as a control table as described above,
In the case where the heads are driven and controlled based on this control table, unless a table element (drive control parameter) is created according to the characteristics of the target head, differences in characteristics between the heads that occur during the head manufacturing process Cannot be compensated for, and the head is driven and controlled with inappropriate parameters.

That is, the ink-jet head is composed of fine parts, is very complicated to manufacture, and often has a wide variety of processes. Therefore, it is difficult to manufacture many heads having uniform characteristics. By using the drive control parameters according to the characteristics of the head, the drive of the head can be finely controlled, and a high-quality image can be output.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to enable a simple configuration to drive and control an ink jet recording apparatus with driving control parameters corresponding to head characteristics.

[0010]

According to a first aspect of the present invention, there is provided an ink jet recording apparatus having a recording head for recording image information by ejecting ink droplets onto a recording medium, and providing a desired ink. In an ink jet recording apparatus for generating a drive signal for the recording head for obtaining a droplet ejection amount and an ink droplet ejection speed based on a control table, a relative relative speed between the recording head and the recording medium under a specific driving condition. A storage unit is provided which stores a neural network unit which uses speed information and environmental information relating to environmental conditions as input information, and outputs drive conditions of the recording head as output information.

According to a second aspect of the present invention, there is provided an ink jet recording apparatus comprising a recording head for recording image information by discharging ink droplets onto a recording medium, and performing the recording to obtain a desired ink droplet discharge amount and ink droplet discharge speed. In an ink jet recording apparatus that generates a drive signal for a head based on a control table, relative speed information on a relative speed between the recording head and the recording medium under a specific driving condition and a distance between the recording head and the recording medium. A storage unit is provided which stores a neural network unit which uses distance information and environmental information relating to environmental conditions as input information, and outputs driving conditions of the recording head as output information.

According to a third aspect of the present invention, in the inkjet recording apparatus of the first or second aspect,
The neural network means stored in the storage means can be additionally learned.

According to a fourth aspect of the present invention, there is provided the ink jet recording apparatus according to any one of the first to third aspects, further comprising means for notifying that the value deviates from a preset control parameter setting range.

6. The recording medium according to claim 5, further comprising a recording head for recording image information by discharging ink droplets onto a recording medium, and for obtaining a desired ink droplet discharge amount and ink droplet discharge speed. A storage medium storing information to be provided to an ink jet printing apparatus that generates a drive signal for the print head based on a control table, wherein relative speed information relating to a relative speed between the print head and the print medium under a specific drive condition and environmental conditions Neural network means for inputting environmental information about the printhead as input information and output driving conditions of the printhead as output information.

7. The recording medium according to claim 6, further comprising a recording head for recording image information by discharging ink droplets onto a recording medium, and obtaining a desired ink droplet discharge amount and ink droplet discharge speed. A storage medium storing information to be provided to an ink jet printing apparatus that performs generation of a drive signal for the print head based on a control table, wherein relative speed information relating to a relative speed between the print head and the print medium under a specific drive condition and the printing. Neural network means for storing distance information on a distance between a head and the recording medium and environmental information on environmental conditions as input information and driving conditions of the recording head as output information are stored.

A storage medium according to claim 7 is the storage medium according to claim 5 or 6, wherein the stored neural network means can perform additional learning.

An eighth aspect of the present invention is the storage medium according to any one of the fifth to seventh aspects, wherein information for notifying that the value deviates from a preset control parameter setting range is stored.

According to a ninth aspect of the present invention, there is provided a control table creation method for mounting a recording head for recording image information by ejecting ink droplets onto a recording medium, and obtaining a desired ink droplet ejection amount and ink droplet ejection speed. In a control table creation method for creating the control table of an ink jet printing apparatus that generates a drive signal for a printhead based on a control table, relative speed information on a relative speed between the printhead and the recording medium under a specific drive condition The control table is created by neural network means that uses environment information relating to environmental conditions as input information and drive conditions of the recording head as output information.

According to a tenth aspect of the present invention, there is provided a control table creating method for mounting a recording head for recording image information by ejecting ink droplets onto a recording medium, and obtaining a desired ink droplet ejection amount and ink droplet ejection speed. In a control table creation method for creating a control table of an inkjet printing apparatus that performs generation of a drive signal for a printhead based on a control table, relative speed information on a relative speed between the printhead and the recording medium under a specific drive condition, A configuration in which the control table is created by using neural network means that takes distance information about a distance between the recording head and the recording medium and environmental information about environmental conditions as input information, and outputs driving conditions of the recording head as output information. did.

The control table creation method according to claim 11 is the control table creation method according to claim 9 or 10, wherein the neural network means can perform additional learning.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic block diagram of a control unit of a line printer which is a line type ink jet recording apparatus to which the present invention is applied.

The control unit of the line printer includes a microcomputer (hereinafter referred to as a “CP”) that controls the entire printer.
U ". 1) ROM 2, which also serves as storage means for storing information such as control tables, neural network programs, applications, etc .; RAM 3, which is used as a working memory, etc .; and image data (image information) received from the host in necessary colors. A color processing circuit 4 for performing processing such as decomposition into data, an image memory 5 for storing data obtained by processing image data, and a parallel input / output (PIO)
Port 6, input buffer 7, and parallel input / output (PI
O) port 8 and parallel input / output (PIO) port 9
And a head driving circuit 11 for driving and controlling a recording head 10 composed of a line type ink jet head, a driver 13 for driving and controlling a motor 12 for conveying a recording medium, and the like.

The PIO port 6 has image information (printing information) from the host such as a personal computer, information indicating whether or not to perform double-sided printing, information indicating the type of paper, and the operation panel 14. Various kinds of instruction information are input, and required information is transmitted to the host and the display unit 15 of the operation panel through the PIO port 6.

The control signal and print data for the above-described head drive circuit 11 and driver 12 are transmitted via the PIO port 8. Further, a temperature sensor 16 for detecting an environmental temperature, which is one of the environmental conditions, a speed sensor 17 for detecting a relative speed between the recording head 10 and the recording medium via the PIO port 9, and a speed sensor 17 for detecting the relative speed between the recording head 10 and the recording medium. Detection signals from a distance sensor 18 for detecting a distance, a volume measuring device 19 for measuring an ink droplet volume, various sensors such as a CCD sensor for imaging ink dots on a recording medium, and a measuring device are input. Note that a speedometer can be used as the speed sensor 17 that detects the relative speed between the recording head 10 and the recording medium, and a distance meter is used as the distance sensor 18 that detects the distance between the recording head 10 and the recording medium. Can be.

Here, the recording head 10 uses an electromechanical transducer such as a piezoelectric element, an electrothermal transducer such as a heating resistor, or uses an electrostatic force between the diaphragm and the electrode. Can be configured.

As an ink jet head using a piezoelectric element, for example, the one shown in FIG. 2 can be used. This ink jet head includes a pressure generating unit 11 and a flow path unit 22. The pressure unit 21 stacks a pressure chamber forming substrate 24 that forms a plurality of pressure chambers 23 on a communication path forming substrate 25 that has formed communication paths 26 a and 26 b to the pressure chamber 23. A vibration plate 27 for sealing one surface of the pressure chamber 23 is laminated on the upper side, and a lower electrode 28, a piezoelectric film (piezoelectric element) 29 and an upper electrode 30 are laminated on the vibration plate 27 in this order.

The flow path unit 22 includes the nozzle forming substrate 3
1. An ink supply port 34 for sequentially supplying ink to the inside of an ink flow path forming substrate 32, 33
A reservoir chamber 35 for storing ink supplied from the ink supply port 34, an ink supply path 36 also serving as a fluid resistance unit for supplying ink in the reservoir chamber 35 to the pressure chamber 23, A nozzle 37 for discharging and a nozzle communication path 39 that connects the pressure chamber 23 and the nozzle 38 are formed. The pressure generating unit 21 and the flow path unit 22 are joined with an adhesive.

In this ink jet head,
By selectively applying a driving waveform between the upper electrode (common electrode) 30 and the lower electrode 28, the piezoelectric film 29 is selectively distorted and deformed with the vibration plate 27, and the pressure is reduced. The pressure in the chamber 23 increases, and ink droplets are ejected from the nozzles 37.

As the electrostatic ink jet head, for example, the one shown in FIG. 3 can be used. The inkjet head includes a first substrate 41 made of a silicon substrate, a second substrate (electrode substrate) 42 made of a Pyrex glass substrate or the like provided below the first substrate 41, and a first substrate 41. A plurality of (only one is shown for convenience) nozzle holes 44, a discharge chamber 45 to which each nozzle hole 44 communicates,
A common ink liquid chamber 47 and the like communicating with each ejection chamber 45 via a fluid resistance portion 46 are formed.

The first substrate 41 has a recess for forming a discharge chamber 45 and a diaphragm (first electrode) 48 forming a bottom of the discharge chamber 45, a groove for forming a fluid resistance part 46, and a common ink. A concave portion forming the chamber 47 is formed. In addition, a predetermined (here, 1 μm)
And 2), a second electrode 52 opposed to the second electrode 52 is provided, and an actuator section is constituted by the second electrode 52 and the vibration plate 48 as the first electrode. Further, a plurality of nozzle holes 44 and an ink supply port 53 for supplying ink to the common ink chamber 47 are formed in the third substrate 43.

In this ink jet head, when a driving voltage is applied between the vibration plate 48 as the first electrode and the second electrode 52, the vibration plate 48 is deformed by the electrostatic force, and the discharge chamber 45 As the internal volume changes, ink droplets are ejected from the nozzle holes 44.

Therefore, an embodiment in which the present invention is applied to this line printer will be described with reference to FIGS. In order to eject ink droplets from the inkjet head, the nozzle 3 for ejecting ink droplets as described above is used.
A drive waveform (drive signal) is given to actuator means such as the piezoelectric element 29 corresponding to the nozzle 8 and the electrode 52 corresponding to the nozzle hole 44.

Here, the drive signal given to the actuator means has several control parameters. That is,
For example, for an ink jet head using a piezoelectric element, as shown in FIG.
There are a rise time constant tr, a drive voltage Vp, a voltage value duration (pulse width) Pw, a fall time constant tf, and the like. By changing these control parameters, the ejection characteristics of the head, that is, the ink droplet volume (ink) Droplet ejection amount, ejection amount) Mj, ink droplet speed (ink droplet ejection speed, droplet speed)
Vj can be changed.

[0034] For example, the driving waveform P and the ink droplet volume Mj,
The relation of the ink droplet speed Vj is that the start time constant tr is constant.
When the drive voltage Vp is changed as shown in FIG.
As the drive voltage Vp increases, the ink droplet volume Mj
Increases. In addition, as shown in FIG.
In this case, the ink droplet speed Vj increases as
In the region of Vjh, satellites are generated,
Since an air bubble is easily mixed, an unstable ejection state is obtained.
When the driving voltage Vp is reduced, the ink droplet speed Vj is slowed down.
However, the ink ejection direction is not correct in the region of Vj <VjL.
When the ink becomes stable or when the ink droplet speed Vj is fast,
The drop landing position shifts.

The relationship between the rise time constant tr and the ink droplet velocity Vi is as shown in FIG.
Is longer, the ink droplet speed Vj becomes slower, and if the rise time constant tr is set shorter, the ink ejection speed Vj becomes faster, and the drive voltage Vp is increased (Vp1 <
Vp3), it is possible to reduce the drop in the ink droplet speed Vj even if the start-up time constant tr is increased.

By the way, when the environmental temperature changes, especially the viscosity of the ink changes, the ejection characteristics of the head change, and the desired values (the ink droplet volume Mj and the ink droplet speed Vj) specified from the image quality are changed. ) Cannot be obtained.

Therefore, in order to change the drive signal (drive waveform) according to the environmental temperature, the drive signal is generated based on the control table. FIG. 8 shows an example of this control table. Here, parameter set A when the environmental temperature is lower than 10 ° C., and parameter set B when the ambient temperature is 10 to 20 ° C.
The drive control parameters defined by the parameter set C at 〜30 ° C., the parameter set D at 30 to 40 ° C., and the parameter set E exceeding 40 ° C. are used.

Each parameter set is composed of control parameters 1, control parameters 2, 3,..., M. For example, referring to FIG. 4, the drive signal generation timing T is control parameter 1, the rise time constant tr is control parameter 2, the drive voltage duration Pw is control parameter 3, the fall time constant tf is control parameter 4, the drive voltage Vp. Is defined as control parameter 5.

For example, in an environment of 15 ° C., a drive waveform is generated using the drive control parameters defined by the parameter set B, and when the environmental temperature reaches 38 ° C., the drive control parameters defined by the parameter set D are generated. Is used to drive the head, so that a desired ink droplet volume Mj and ink droplet speed Vj can be obtained.

In general, in a line printer, a recording medium (usually paper, but not limited to paper, on which ink droplets land) is conveyed continuously, making the recording head longer. Also in the ink jet line printer described above, it is required that the conveyance of the recording medium is not intermittent but continuous, from the viewpoint of improving the printing speed.

A first embodiment of a method for creating a control table serving as a basis for generating a drive signal and a printer (recording apparatus) to which the method is applied will be described. First, the recording head 10 is driven under the parameters of the specific environmental temperature and the driving condition, and the head ejection characteristics in that case are measured. More specifically, the recording head 10 is driven under a specific temperature environment using driving control parameters necessary for driving the recording head 10, and the ink droplet speed Vj and the ink droplet volume (ejection amount) Mj are measured. In addition, the relative speed between the recording head 10 and the recording medium is measured as the driving condition. This can be measured using a speedometer or volume measurement device.

Then, by using a hierarchical neural network, as shown in FIG. 9, the neuron of the input layer is input with environmental driving conditions (relative speed and environmental temperature) and ink droplet ejection characteristics of the recording head 10 as input information. Some ink drop velocity V
j, an ink droplet volume Mj, and drive control parameters 1 to m, which are output information, are assigned to neurons in the output layer.

Using the measured data of the recording head 10 as learning data, network learning is performed by the back propagation method. During this learning process, an inverse model of the image forming (recording) system including the characteristics of the recording head 10 is formed in the neural network.

Therefore, when the learning is completed, the desired head ejection characteristics are given to the neurons in the input layer of the neural network under the driving environment conditions such as the environmental temperature and the relative speed between the recording head 10 and the recording medium.
The drive control parameters 1 to m necessary to obtain the desired head ejection characteristics are output to the neurons in the output layer.

It should be noted that, besides the data used for learning, if the driving environment conditions and desired injection characteristics are input to the network by the generalization ability of the neural network, the driving control parameters can be output.

That is, by using a network constructed by learning and inputting head ejection characteristics under predetermined environmental conditions as input information, drive control parameters can be obtained in output information of the network. By obtaining the respective drive control parameters, the elements of the control table can be determined, and finally the control table can be created.

In particular, in a line printer, when printing on a recording medium continuously conveyed, the recording head 1 is used.
The relative speed between 0 and the recording medium and the ink droplet velocity Vj have a great effect on the positions of ink dots formed on the recording medium. Also, the transport speed changes for each recording medium,
Even with the same recording medium, there is a possibility that the conveyance speed may partially change. Even in such a case, an ink dot can be formed at a desired position by correcting the drive signal generation timing T based on the relative speed and the ink droplet speed Vj.

As described above, the control is performed by the neural network means which uses the relative speed information on the relative speed between the recording head and the recording medium under specific driving conditions and the environmental information on the environmental conditions as input information and the driving conditions of the recording head as output information. By creating the table, fine control parameters corresponding to the characteristics of the printhead can be obtained, so that an inkjet printing apparatus that outputs a high-quality image can be obtained.

In this case, the inverse model of the printing system including the characteristics of the recording head can be easily constructed by using the learning function of the neural network without having to obtain the physical characteristics of the recording head through detailed experiments and analysis. I can do it. The network used is not limited to the hierarchical type. Also, the learning method used is not limited to the back propagation method, and may be used as appropriate according to the type of network and implementation conditions.

In addition, when the desired ejection characteristics of the recording head change due to a change in specifications during the development stage of the ink jet head or a change in the material used during the manufacturing stage, etc., parameters other than the initially set drive control parameters may be used. May occur. At this time, by increasing the number of neurons in the output layer of the neural network and performing additional learning anew, it is possible to add (increase) a new drive control parameter and adjust an existing parameter.

In this case, the number of neurons in the output layer of the neural network is configured in advance, and learning is performed so that the output becomes “0”. When additional learning is required, It is also possible to newly assign drive control parameters to these neurons.
This makes it possible to respond to a change in the characteristics of the printhead and a change in the control parameters in a simple manner without wasting the previous data.

Therefore, in this line printer,
The above-mentioned predetermined driving conditions and control tables are stored as data in a memory such as the ROM 2. Further, the neural network can use the one established as an algorithm and can be realized as a computer program. Stored.

A speedometer (speed sensor 17) and a volume measuring device 19 for measuring the ink droplet speed and ink droplet volume, which are the head ejection characteristics, and the relative speed between the recording head and the recording medium are provided. Is converted into an electric signal and input. In addition, a temperature sensor 16 for detecting an environmental temperature as an environmental condition is provided to capture the environmental temperature. In addition,
Even if the environmental temperature is not quantized as in a table element, the temperature of the environment to be injected can be directly used as input information of the neural network.

As described above, in the ink jet recording apparatus, relative speed information on the relative speed between the recording head and the recording medium under specific driving conditions and environmental information on environmental conditions are input information, and the driving conditions of the recording head are output information. Providing storage means storing a neural network means for measuring data of head ejection characteristics in an ink jet recording apparatus, creating an element of an appropriate control table on the apparatus, and driving the recording head under appropriate driving conditions Can be.

Therefore, even if the characteristics of the recording head and the transport speed of the recording medium change due to a change over time after being mounted on the recording apparatus, that is, even if the characteristics of the printer system change, the proper driving of the recording head can be achieved. Control can be performed, and a high-quality output image can be held.

Since the neural network can be implemented as a computer program, it can be easily modified or changed. Further, since additional learning is also possible, by performing additional learning as described above, it is possible to add (increase) a new drive control parameter and adjust an existing parameter corresponding to a change in the characteristics of the printer system.

As a result, it is possible to realize an ink jet recording apparatus capable of coping with a change in the characteristics of the printer system and a change in the control parameters by a simple method of simply changing the data (electronic data) mounted on the printer.

When a control table as shown in FIG. 8 is created, a range in which the head ejection characteristics can be compensated using control parameters is often determined in advance.
That is, there is a case where there is a recording head or a recording apparatus which cannot obtain a desired head ejection characteristic even if the control parameters are adjusted. The setting range of the control parameter is limited, and it is not possible to set a higher (or lower) value.

As described above, the desired head ejection characteristics cannot be obtained, such as when the recording head mounted on the recording apparatus deteriorates or breaks down with the passage of time, or when the transport mechanism of the recording medium has an abnormality. Can be considered.

These can be realized by setting an appropriate range of the drive control parameter which is output information of the neural network in advance. In such a case, the display device (display unit 15) mounted on the recording device displays and notifies an abnormality of the device system including the recording head 10.
As a result, the user and service personnel can easily grasp the abnormality. It is also possible to notify the host system and display it on the display device of the host.

Next, a description will be given of a second embodiment of a method of creating a control table serving as a basis for generating a drive signal and a printer (recording apparatus) to which the method is applied. The image formation in the ink jet printing is performed by landing ink droplets ejected from the recording head 10 on a recording medium and forming ink dots on the recording medium. The position, that is, the landing position of the ink droplet, greatly affects the image quality. That is, the formed image is composed of minute ink dots,
If the formation position of the ink dot on the recording medium deviates from the target position, a gap is formed between adjacent ink dots, causing a defect such as a white stripe or dropout, or affecting color development.

For this reason, the ink droplet speed and the drive signal generation timing for ejection are determined at the initial design stage so that the formation positions of the ink dots do not fluctuate. Due to a change in the distance, a desired ink dot formation position may not be obtained at a predetermined ink droplet speed or ejection drive signal generation timing.

Therefore, a drive control parameter for performing appropriate ink droplet ejection corresponding to the distance between the recording head 10 and the recording medium is required. For this purpose, the recording head 10 is driven at specific environmental temperature and driving condition parameters, and the distance between the recording head 10 and the recording medium at this time is measured.

More specifically, the recording head 10 is driven under a specific temperature environment by using driving control parameters necessary for driving the recording head 10, and the ink droplet speed Vj, the ink droplet volume Mj, the recording head 10 Relative speed between the recording medium and
The distance between the recording head 10 and the recording medium is measured.

As shown in FIG. 10, using a hierarchical neural network, the input layer neurons are driven by the environmental temperature, which is the driving environmental condition, the relative speed between the recording head 10 and the recording medium, and the recording head 10 The distance between the recording medium and the recording medium, the ink droplet ejection speed Vj and the ejection amount (ink droplet volume) Mj are assigned, and these are used as input information. Also, drive control parameters are assigned to neurons in the output layer, and these are used as output information.

Using the measured data of the recording head 10 as learning data, network learning is performed by the back propagation method. Therefore, when the learning is completed, desired head ejection characteristics (ink droplet speed Vj and ejection amount Mj) are determined based on the environmental temperature, the relative speed between the recording head 10 and the recording medium, and the distance between the recording head 10 and the recording medium. Is given to the neurons in the input layer, the necessary drive control parameters 1 to m are output to the neurons in the output layer.

In addition to the data used for learning, if the driving environment conditions and desired head ejection characteristics are input to the network by the generalization ability of the neural network,
Drive control parameters can be output.

That is, by using a network constructed by learning and inputting injection characteristics under predetermined environmental conditions as input information, drive control parameters required therefrom can be obtained in output information of the network. Therefore, the elements of the control table can be determined by changing the environmental conditions to obtain the respective drive control parameters, and finally, the control table can be created.

The formation position of the ink dots on the recording medium moving during printing depends not only on the relative speed between the recording head 10 and the recording medium as described above, but also on the recording head 10 and the recording medium. It also depends on the relationship between the distance to the medium and the ink droplet speed Vj. Therefore, by correcting the drive signal generation timing based on the distance information, it is possible to change the ink droplet ejection timing in consideration of the ink droplet ejection speed Vj and the flight time of the ink formed on the recording medium. Thus, an ink dot can be formed at a desired position on the recording medium, and a good image can be obtained.

As described above, the relative speed information on the relative speed between the recording head and the recording medium under the specific driving conditions,
By creating a control table using neural network means that uses distance information about the distance between the recording head and the recording medium and environmental information about environmental conditions as input information and driving conditions of the recording head as output information, Since fine control parameters can be obtained according to the characteristics and the image forming characteristics, it is possible to obtain an ink jet recording apparatus that outputs a high-quality image.

The inverse model of the printer system including the printhead characteristics can be constructed by using the learning function of the neural network without having to obtain the physical characteristics of the printhead through detailed experiments and analysis. it can.

The network used is not limited to the hierarchical type. Also, the learning method used is not limited to the back propagation method, and can be used as appropriate according to the type of network and the implementation conditions. Furthermore, changes in specifications during the development stage of the inkjet head, changes in materials used during the manufacturing stage, etc. may change the desired ejection characteristics of the recording head, and may cause parameters other than the initially set drive control parameters. There is. In this case, as described above, the number of neurons in the output layer of the neural network is increased, and additional learning is performed again to add (increase) new drive control parameters and adjust existing parameters. Can be.

In this case, the number of neurons in the output layer of the neural network is configured in advance, and learning is performed so that the output becomes “0”. A drive control parameter may be newly assigned to these neurons.
As a result, it is possible to cope with a change in the characteristics of the recording head and a change in the control parameters by a simple method without wasting the conventional data.

Therefore, in this line printer,
The above-mentioned predetermined driving conditions and control tables are stored as data in a memory such as the ROM 2. Further, the neural network can use the one established as an algorithm and can be realized as a computer program. Stored.

Then, a speedometer (speed sensor 17) for measuring the ink droplet speed and ink droplet volume, which are the head ejection characteristics, and the relative speed between the recording head and the recording medium, a volume measuring device 19, and the recording head 8 are provided. A distance sensor 18 for measuring the distance to the recording medium and an image sensor 20 such as a CCD for detecting the positions of ink dots on the recording medium are provided, which are converted into electric signals and input. Further, a temperature sensor 14 for detecting an environmental temperature as an environmental condition.
To capture the ambient temperature. It should be noted that the environmental temperature does not need to be quantized as in a table element, and the temperature of the environment to be jetted can be directly used as input information of the neural network.

As described above, in the ink jet recording apparatus, the relative speed information on the relative speed between the recording head and the recording medium under the specific driving conditions, the distance information on the distance between the recording head and the recording medium, and the environmental information on the environmental conditions By providing storage means storing neural network means for inputting information as input information and driving conditions of the recording head as output information, data of head ejection characteristics and ink dot positions formed on a recording medium in an ink jet recording apparatus can be stored. It is possible to measure, create an element of an appropriate control table on the apparatus, and drive the recording head under appropriate driving conditions.

Therefore, even if the characteristics of the recording head and the transport speed of the recording medium change due to a change over time after being mounted on the recording apparatus, that is, even if the characteristics of the printer system change, the proper driving of the recording head can be achieved. Control can be performed, and a high-quality output image can be held.

Since the neural network can be implemented as a computer program, it can be easily modified or changed. Further, since additional learning is also possible, by performing the additional learning as described above, a change in the characteristics of the recording head or the distance between the recording head and the recording medium, that is, a new change corresponding to the characteristic change (fluctuation) of the printer system. It is possible to add (increase) the drive control parameters and adjust the existing parameters.

As a result, it is possible to realize an ink jet recording apparatus capable of coping with a change in the characteristics of the printer system and a change in the control parameters by a simple method of simply changing the data (electronic data) mounted on the printer.

When a control table as shown in FIG. 8 is created, a range in which the head ejection characteristics can be compensated using control parameters is often determined in advance.
That is, there is a case where there is a recording head or a recording apparatus which cannot obtain a desired head ejection characteristic even if the control parameters are adjusted. The setting range of the control parameter is limited, and it is not possible to set a higher (or lower) value.

As described above, the desired head ejection characteristics cannot be obtained, such as when the recording head mounted on the recording apparatus has deteriorated or failed due to aging, or when the transport mechanism of the recording medium has an abnormality. Can be considered.

These can be realized by setting in advance the appropriate range of the drive control parameters which are the output information of the neural network. In such a case, the display device (display unit 15) mounted on the recording device displays and notifies an abnormality of the device system including the recording head 10.
As a result, the user and service personnel can easily grasp the abnormality.

Next, a third embodiment of the present invention will be described. In the third embodiment, relative speed information relating to the relative speed between the recording head and the recording medium under specific driving conditions and environmental information relating to environmental conditions, which are realized as a program and described in the first embodiment, are input information. And a neural network that uses the driving conditions of the recording head as output information is stored in a storage medium.

Therefore, by transplanting the neural network of this recording medium from a host side of a personal computer or the like connected to the ink jet recording apparatus to a storage means such as a memory of the ink jet recording apparatus, the ink jet recording apparatus can operate under a specific driving condition. The recording head is driven by using a control table created by a neural network means that uses relative speed information on a relative speed between the recording head and a recording medium and environmental information on environmental conditions as input information and driving conditions of the recording head as output information. Since control can be performed and fine control parameters can be obtained according to the characteristics of the recording head and the image forming characteristics, a high-quality image can be output.

As described in the second embodiment, relative speed information on the relative speed between the recording head and the recording medium under specific driving conditions, which is realized as a program, It is also possible to store a neural network in the storage medium in which the distance information relating to the distance and the environmental information relating to the environmental conditions are input information and the driving conditions of the recording head are output information.

In this case, the neural network of the recording medium is transferred from the host side of a personal computer or the like connected to the ink jet recording apparatus to storage means such as a memory of the ink jet recording apparatus.
The inkjet recording apparatus uses the relative speed information about the relative speed between the recording head and the recording medium under specific driving conditions, the distance information about the distance between the recording head and the recording medium, and the environmental information about the environmental conditions as input information, and the driving conditions of the recording head. The print head can be driven and controlled using a control table created by a neural network means that uses the output information as the output information, and fine-grained control parameters corresponding to the characteristics of the print head and image forming characteristics can be obtained. Can output a simple image.

Note that the network to be used is not limited to the hierarchical type, the learning method to be used is not limited to the back propagation method, and it can be appropriately used according to the type of the network and the implementation conditions. Can be performed, and information for notifying that the control parameter has deviated from the preset control parameter setting range is the same as that described in the first and second embodiments.

In each of the above embodiments, a line printer has been described as an example of an ink jet recording apparatus. However, the present invention can be similarly applied to a serial type ink jet recording apparatus. The same can be applied to the device. The inkjet head to be used is a piezo type inkjet head using an electromechanical transducer,
The invention is not limited to the electrostatic ink jet head, and other actuator means may be used.

[0089]

As described above, according to the ink jet recording apparatus of the first aspect, relative speed information on the relative speed of the recording head and the recording medium under specific driving conditions and environmental information on environmental conditions are input information. Since the configuration includes a storage unit that stores a neural network unit that uses the driving conditions of the recording head as output information, an appropriate driving control parameter is easily created on the recording apparatus, and The head can be driven, fine-grained control can be performed in accordance with the characteristics of the recording device, and high-quality images can be obtained. Even if it changes, appropriate drive control parameters can be created,
High quality images can be maintained.

According to the ink jet recording apparatus of the present invention, relative speed information on the relative speed between the recording head and the recording medium under specific driving conditions, distance information on the distance between the recording head and the recording medium, and environmental information on the environmental conditions. And the storage means storing the neural network means that uses the input information as the input information and the driving conditions of the recording head as the output information. The head can be driven under a variety of driving conditions, fine-grained control can be performed according to the characteristics of the recording device, and high-quality images can be obtained. Even if the transport speed changes, appropriate drive control parameters can be created, and a high-quality image can be maintained.

According to the ink jet recording apparatus of the third aspect, in the ink jet recording apparatus of the first or second aspect, the additional learning of the neural network means stored in the storage means can be performed. Addition and adjustment of existing parameters can be performed, and it is possible to easily respond to changes in the characteristics of the printing apparatus and changes in control parameters.

According to a fourth aspect of the present invention, there is provided an ink jet recording apparatus as set forth in any one of the first to third aspects, further comprising means for notifying that the control parameter is out of a preset control parameter setting range. Therefore, it is possible to notify the abnormality or failure of the recording head, or that the recording medium is trying to use a recording medium that cannot keep the distance between the recording head and the recording medium within a predetermined range, It is easier for users and service personnel to respond.

According to the storage medium of the present invention, the relative speed information on the relative speed between the recording head and the recording medium under specific driving conditions and the environmental information on the environmental conditions are input information, and the driving conditions of the recording head are output information. Since the neural network means is configured to be stored, the head can be driven with appropriate drive control parameters by transplanting to an inkjet recording apparatus, and fine-grained control according to the characteristics of the recording apparatus can be performed. In addition, it is possible to obtain a high-quality image, and it is also possible to create an appropriate drive control parameter even if the head characteristics and the transport speed of the recording medium change due to aging or the like, and maintain a high-quality image. be able to.

According to the storage medium of the sixth aspect, relative speed information on the relative speed between the recording head and the recording medium under specific driving conditions, distance information on the distance between the recording head and the recording medium, and environment information on environmental conditions are stored. Since the configuration is such that the neural network means that stores the driving conditions of the recording head as the input information as the output information is stored, more appropriate driving control parameters are easily created on the recording apparatus, and the head is controlled under the appropriate driving conditions. It can be driven, can perform fine-grained control according to the characteristics of the recording device, can obtain high-quality images, and changes in head characteristics and the transport speed of the recording medium due to aging, etc. Even so, it is possible to create appropriate drive control parameters,
High quality images can be maintained.

According to a seventh aspect of the present invention, in the storage medium of the fifth or sixth aspect, the stored neural network means is configured to be capable of performing additional learning. Can be adjusted, and it is possible to easily respond to changes in the characteristics of the printing apparatus and changes in control parameters.

According to the storage medium of claim 8, the storage medium of any one of claims 5 to 7, wherein the information for notifying that the control parameter has deviated from a preset control parameter setting range is stored. Therefore, it is possible to notify the abnormality or failure of the recording head, or that the recording medium is trying to use a recording medium that cannot keep the distance between the recording head and the recording medium within a predetermined range, It is easier for users and service personnel to respond.

According to the control table creation method of the ninth aspect, relative speed information on the relative speed between the recording head and the recording medium under specific driving conditions and environmental information on environmental conditions are used as input information and the driving conditions of the recording head are output. Since the control table is created by the neural network means used as information, it is possible to easily create appropriate drive control parameters and drive the head under appropriate drive conditions, and to obtain the characteristics of the recording apparatus. And fine-grained control can be performed in accordance with the condition, and a high-quality image can be obtained. Moreover, even if the head characteristics or the transport speed of the recording medium change due to a change over time, appropriate drive control parameters can be created, and a high-quality image can be maintained.

According to the control table creation method of the tenth aspect, relative speed information relating to the relative speed between the recording head and the recording medium under specific driving conditions, distance information relating to the distance between the recording head and the recording medium, and environmental conditions. Since the configuration is such that the control table is created by using a neural network means that uses the environment information as input information and the print head drive conditions as output information, it is easy to create more appropriate drive control parameters and to set appropriate drive conditions. , The head can be driven, fine control can be performed according to the characteristics of the recording apparatus, and a high-quality image can be obtained. Moreover, even if the head characteristics or the transport speed of the recording medium change due to a change over time, appropriate drive control parameters can be created, and a high-quality image can be maintained.

According to the control table creation method of claim 11, in the control table creation method of any one of claims 9 and 10, the neural network means is configured to be able to perform additional learning. Addition and adjustment of existing parameters can be performed, and it is possible to easily respond to changes in the characteristics of the printing apparatus and changes in control parameters.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a control unit of a line-type inkjet printer as an inkjet recording apparatus to which the present invention is applied.

FIG. 2 is a cross-sectional explanatory view showing an example of a piezo-type inkjet head constituting a recording head of the recording apparatus.

FIG. 3 is an explanatory cross-sectional view showing an example of an electrostatic inkjet head constituting a recording head of the recording apparatus.

FIG. 4 is an explanatory diagram for explaining control parameters of a driving waveform.

FIG. 5 is an explanatory diagram illustrating an example of a relationship between a driving voltage of a driving waveform and an ink droplet ejection amount.

FIG. 6 is an explanatory diagram illustrating an example of a relationship between a driving voltage of a driving waveform and an ink droplet ejection speed.

FIG. 7 is an explanatory diagram illustrating an example of a relationship between a rising time constant of a driving waveform, an ink droplet ejection speed, and a driving voltage.

FIG. 8 is an explanatory diagram showing an example of a control table.

FIG. 9 is an explanatory diagram showing an example of a hierarchical neural network.

FIG. 10 is an explanatory diagram showing another example of a hierarchical neural network.

[Explanation of symbols]

2 ROM, 10 recording head, 11 head drive circuit, 15 display unit, 16 temperature sensor, 16 speed sensor, 17 distance sensor, 18 distance sensor, 19 volume measurement device, 20 image sensor .

Continued on the front page F-term (reference) 2C056 EA07 EA08 EA20 EB29 EB30 EB35 EB36 EB37 EC26 EC28 EC31 EC37 EC38 EC42 EC72 FA03 FA04 FA10 FA13 2C057 AF30 AG44 AG46 AG54 AL11 AL22 AL26 AM15 AM16 AM17 AM21 AN01 AN05 A02 BA01 DB01 DB03 DB04 DE02 DE07 DE08 DE10

Claims (11)

[Claims] 1. A recording head for recording image information by ejecting ink droplets onto a recording medium, and generating a drive signal for the recording head to obtain a desired ink droplet ejection amount and ink droplet ejection speed. In the ink jet recording apparatus performed based on the control table, relative speed information on a relative speed between the recording head and the recording medium under specific driving conditions and environmental information on environmental conditions are input information, and the driving conditions of the recording head are determined. An ink jet recording apparatus comprising storage means for storing neural network means as output information. 2. A recording head for recording image information by discharging ink droplets onto a recording medium, and generating a drive signal for the recording head to obtain a desired ink droplet discharge amount and ink droplet discharge speed. In an ink jet recording apparatus performed based on a control table, relative speed information on a relative speed between the recording head and the recording medium under specific driving conditions, distance information on a distance between the recording head and the recording medium, and an environment on environmental conditions. An ink jet printing apparatus, comprising: storage means for storing neural network means for receiving information as input information and driving conditions of the print head as output information. 3. The ink jet recording apparatus according to claim 1, wherein additional learning of the neural network means stored in the storage means can be performed. 4. An ink jet recording apparatus according to claim 1, further comprising means for notifying that the control parameter has deviated from a preset control parameter setting range. 5. A recording head for recording image information by discharging ink droplets onto a recording medium, and generating a drive signal for the recording head to obtain a desired ink droplet discharge amount and ink droplet discharge speed. A storage medium storing information to be provided to an inkjet printing apparatus based on a control table, wherein relative information on the relative speed between the printhead and the print medium under specific driving conditions and environmental information on environmental conditions are input information. And a storage medium storing neural network means for using drive conditions of the recording head as output information. 6. A recording head for recording image information by discharging ink droplets onto a recording medium, and generating a drive signal for the recording head to obtain a desired ink droplet discharge amount and ink droplet discharge speed. A storage medium storing information to be provided to an ink jet printing apparatus based on a control table, wherein relative speed information on a relative speed between the print head and the print medium under a specific driving condition, the print head and the print medium A storage medium storing neural network means for inputting distance information relating to the distance and environmental information relating to environmental conditions as input information, and using drive conditions of the recording head as output information. 7. The storage medium according to claim 5, wherein the stored neural network means can perform additional learning. 8. The storage medium according to claim 5, wherein information for notifying that the control parameter has deviated from a preset control parameter setting range has been stored. 9. A recording head for recording image information by ejecting ink droplets onto a recording medium, and generating a drive signal for the recording head to obtain a desired ink droplet ejection amount and ink droplet ejection speed. In a control table creation method for creating the control table of an ink jet printing apparatus based on a control table, relative speed information on a relative speed between the printhead and the recording medium under specific driving conditions and environment information on environmental conditions are input. Information and
A control table creation method, wherein the control table is created by a neural network unit that uses drive conditions of the recording head as output information. 10. A recording head for recording image information by discharging ink droplets onto a recording medium, and generating a drive signal for the recording head to obtain a desired ink droplet discharge amount and ink droplet discharge speed. In a control table creation method for creating a control table of an ink jet printing apparatus based on a control table, relative speed information on a relative speed between the printhead and the print medium under a specific driving condition, the printhead and the print medium A control table creating method for creating the control table using neural network means using distance information relating to the distance to the printer and environmental information relating to environmental conditions as input information and driving conditions of the recording head as output information. 11. The control table creation method according to claim 9, wherein said neural network means can perform additional learning.