JP3476795B2 - Tool speed detection system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to gravure engraving and, more particularly, to an engraving apparatus (system) and method using digital tool path planning, digital tuning, and closed loop feedback control. In addition, this application is a corresponding application of a part continuation application of US Patent Application No. 08 / 434,592 filed on May 4, 1995.

[0002]

2. Description of the Related Art A general electromechanical engraving method has a step of cutting a minute area (called a cell) of copper from the surface of a copper cylinder. In a general method, cells are formed by superimposing a screening signal and an image signal. The screening signal is an AC sinusoidal waveform and an image signal is added to it to drive or vibrate a cutting tool or cutter needle (stylus) to engrave cells.

[0003]

Heretofore, efforts have been made exclusively to modify the image signal in order to improve the quality of the engraved image. In addition, edge enhancement, selective linearization, engraving head speedup, and pulse modulation have also been used to modulate the image signal to improve engraving quality. These concepts in conventional engraving technology are described in US Pat. Nos. 5,438,422, 5,42.
4,845; 5,621,533; 5,32
9,215; 5,416,597; 5,42
4,846; 5,402,246; 5,45
4,306; 5,475,914; 5,555
473; 5,440,398; 5,493,9
No. 39; 4,357,633; 4,438,46
No. 0; 4,450,486; 4,451,856
No .; 4,500,929; 5,492,057
No. 5,029,011; 5,519,502
No .; 5,583,647; 5,491,559
No .; 5,422,958; 5,293,426
No. 5,617,217, which shows the apparatus and method conventionally used generally. in this way,
Attempts to improve engraving quality have been made, for example, for the modulation of image signals.

Similarly, US Pat. Nos. 4,245,260 and 5,519,502 disclose techniques for improving engraving quality by linearizing and engraving the engraved portion. . For example, US Pat.
No. 260 discloses a technique of adjusting the position of a cell by modulating a screening signal.

Therefore, a system in which the image signal and the screening function are combined as a reference waveform indicating the tool path of the desired cutter needle, thereby reducing or eliminating the need to modulate the image signal and the screening signal. And a method is needed.

Another problem with conventional devices is that cell placement and screening relies on AC sinusoidal waveforms, which limits engraving quality flexibility. This is because the conventional screening waveform consists of a constant AC sinusoid, and it was difficult to modulate it according to the image to be engraved. Therefore, there is a need for a simple and effective apparatus and method that can modulate data corresponding to the image to be engraved into a signal that can be synthesized as a free tool path directly from the image data.

Further, the conventional engraving head exhibits a resonance characteristic that the output is increased at about 2 kHz and about 5.5 kHz due to its mechanical structure. In order to eliminate such an unwanted resonance, a notch filter has been added so that the frequency response of the engraving head can be predicted. The filter algorithm for this notch filter generally provided a smooth but reduced response. The aforementioned U.S. Pat. No. 4,35
7,633, 4,438,460, 4,450,4
No. 86, 4,500,929 describes a general type engraving apparatus and method utilizing conventional filtering.

Unfortunately, conventional filter techniques generally have resulted in engraving head frequency characteristics that have poor amplitude in the high frequency bands, eg, above 5.5 kHz. Furthermore, in the conventional technology, the user cannot interactively and easily change the characteristics such as the filter coefficient of the filter, and the engraving head cannot be operated and adjusted as desired. In the past, the filter properties were exposed to electrical component errors and could not be transferred from one circuit board to another with the required accuracy.

Therefore, there is a need for a system and method that features an engraving head that allows the tuning filter characteristics to be stored digitally separate from the tuning circuit.
This digital filter characteristic is executed to obtain the desired response characteristic of the engraving head, and in case of circuit failure,
It may be stored in the memory of the exchange circuit with sufficient accuracy.

In the past, error correction or engraving head calibration has been accomplished using a variety of methods and techniques, which are described in US Pat. No. 5,029,011, 5,5.
293,426, 5,416,597, 5,42
2,958, 5,438,422, 5,440,3
No. 98 and the like. For example, some conventional calibration methods measure and compare various characteristics of individual cells in a test strip with desired characteristics. If,
If the difference between the desired characteristic and the actual engraving characteristic is greater than a predetermined tolerance, then the engraving head is adjusted. Generally, prior art methods use optics, strobes, focusing equipment, etc. for such measurements and calibrations. What is really needed is a tool speed and position measurement system that is simple in construction, inexpensive, and easy to install, as well as a system and method for feeding back it.

Therefore, what is really needed is a method that can emotionally and skillfully handle the placement of the engraving area directly from the image data without using or utilizing the screening signal. And the system.

Conventionally, the head response characteristic obtained after a long tuning process is used for the subjective judgment of the tuning operator to adjust the quality. Therefore, each engraving head has different characteristics, and the quality of the engraved image is different for each engraver, and when a composite head is used, the quality is different for each head. .

Therefore, there is a need for an automatic tuning method and apparatus that can reduce variations in the response characteristics of the engraving head. Such a device can not only reduce the engraving head tuning time, but also increase reproducibility.

[0014]

As described above, the first object of the present invention is to synthesize a desired cutting tool path from image data corresponding to the image to be engraved, thereby providing greater flexibility. An object of the present invention is to provide an engraving device and method capable of improving the engraving quality, etc.

One aspect of the present invention is a method of controlling a path of a tool of an engraving apparatus, which method comprises a step of generating image data corresponding to an image to be engraved, and a plurality of steps based on the image data. And the step of processing these reference points to determine a tool path and driving the tool to engrave a workpiece based on the tool path.

Another embodiment of the present invention is a method for engraving a pattern in an engraving area on a work, which comprises a step of generating image data corresponding to an image to be engraved, and a tool path directly from the image data. The process includes a step of obtaining, a step of determining an engraving signal using the tool path, and a step of driving an engraving head using the engraving signal to engrave the work.

Still another aspect of the present invention is a tool path control device for controlling a path of a tool on an engraving head of an engraving apparatus, which is an image for generating a plurality of reference points corresponding to image data. The image data processing device includes a data processing device, the image data processing device includes a tool path generation device that generates a plurality of reference points for defining a tool path, and the tool path control device includes the image data processing device. And a signal generator connected to the engraving head, the signal generator configured to receive the tool path and drive the engraving head to engrave a workpiece in correspondence with the tool path. .

Further, another embodiment of the present invention is an engraving device for engraving a work, which is provided on the engraving base and the engraving base, and engraves at least one engraving area of the work. An engraving head having a tool; a processing unit connected to the engraving head for receiving image data to generate an engraving signal for engraving the at least one engraving area; A digital tool path planning device for planning a tool path corresponding to data, wherein the processing device uses the tool path to generate the engraving signal.

Yet another aspect of the present invention is a method of generating an engraving signal for controlling an engraving head so that a tool of the engraving head moves in a desired tool path, the method comprising the steps of: And processing the engraving signal so that the frequency response of the engraving head has a substantially constant gain at a frequency equal to or lower than a predetermined frequency.

Yet another aspect of the present invention is an engraving head tuning device for tuning an engraving head so that a tool of the engraving head passes through a desired tool path, the engraving head receiving device receiving an engraving signal and a predetermined signal. And a processor for processing the engraving signal so that the frequency response of the engraving head has a substantially constant gain at a frequency equal to or lower than the frequency.

Yet another embodiment of the present invention is an engraving device for engraving at least one engraving area, which is an engraving table, an engraving head having a tool provided on the engraving table, and connected to the engraving head. An engraving head tuning device, the engraving head tuning device processing the engraving signal such that the frequency response of the engraving head has a substantially constant gain at frequencies below a predetermined frequency. Is characterized by.

Yet another aspect of the present invention is a method of tuning an engraving head, comprising the step of filtering the engraving signal to eliminate unwanted resonances using at least one filter, and at least one filter. Defining a filter constant of the filter, connecting a user interface to the at least one filter, determining whether at least one parameter of the at least one filter needs to be changed, and at least one parameter Adjusting the at least one parameter programmably using the user interface if it needs to be changed.

Yet another embodiment of the present invention is an engraving device, which comprises an engraving table, an engraving head having a tool provided on the engraving table, and at least one parameter provided on the engraving head. At least one filter having at least one filter coefficient and a user interface connected to the at least one filter, wherein the user interface allows a user to change at least one parameter to change a response characteristic of the filter. Is programmable so that it can be adjusted.

Yet another aspect of the present invention is a speed detection system for detecting the position of a cutting tool for engraving a cylinder, which is provided with an armature for holding the cutting tool and by energizing the armature. At least one electromagnetic drive device having at least one drive coil for vibrating the armature; and a sensor provided in association with the at least one electromagnetic drive device for detecting the position of the cutting tool. Characterize.

Yet another aspect of the present invention is a method of stabilizing an engraving head comprising a motor for driving a cutting tool, the first coil of the motor being provided with a first drive signal. Second step and speed of the motor
It is characterized by including a step of detecting using a coil and a step of stabilizing the engraving head using the motor speed.

Yet another embodiment of the present invention is an engraving device for engraving at least one engraving area, which has an engraving base, a cutting tool provided on the engraving base, and an armature holding the cutting tool. Energizing the engraving head, and a head tuning device connected to the engraving head for processing the engraving signal so that the frequency response of the engraving head has a substantially constant gain at a frequency equal to or lower than a predetermined frequency. And at least one electromagnetic drive having at least one drive coil for vibrating the armature according to claim 1, and a sensor provided in association with the at least one electromagnetic drive for determining the speed of the electromagnetic drive. The head tuning device tunes the engraving head resonance in response to the speed and the processed signal. .

Yet another aspect of the present invention is a method for scaling (standardizing, scaling) image data to be engraved, the method generating image data corresponding to the image to be engraved. A step of determining whether the image data is continuous tone data or linework data, and a step of determining if the image data is continuous tone data or linework data, respectively. Generating a gradation reference point or a linework reference point.

Yet another aspect of the present invention is an engraving apparatus for engraving a work, which engraving table and a tool for engraving at least one engraving area of the work. An engraving head, a processing unit connected to the engraving head for receiving image data and generating an engraving signal for engraving at least one engraving area, and a tool path connected to the processing unit for responding to the image data A digital tool path planning device for planning, wherein the processing device uses the tool path to generate the engraving signal.

Yet another aspect of the present invention is a method for controlling a path of a tool of an engraving apparatus, which method includes a step of generating image data corresponding to an image to be engraved, and a method corresponding to the image data. Generating a plurality of reference points for
The method is characterized by including a step of processing these reference points to create a tool path, and a step of driving the tool and engraving a workpiece in response to the tool path.

Yet another object of the present invention is to provide a method for controlling a tool path of an engraving apparatus, which comprises one or more of the following additional or optional configurations. Processing the image data to generate a predetermined number of density values and using the density values to determine a total percentage of image density. -Determining the center of concentration using the predetermined number of loess values.・ The process of specifying the approach reference point where the tool enters the work.・ The process of identifying the escape reference point where the tool escapes from the work. Identifying at least one reference point between the entry reference point and the exit reference point.

Identifying a central reference point between the entry reference point and the exit reference point. Determining the tool path using the entry reference point, the exit reference point, and the center reference point. -Identifying a central reference point between the entry reference point and the exit reference point. Fitting a curve to the entry reference point, the exit reference point, and the center reference point to determine the tool path. A step of identifying a center reference point corresponding to the center of image density. Determining the total image density percentage of the image data. -Determining the entry reference point and the exit reference point using the image total density percentage of the image data. A step of setting the entry reference point and the exit reference point on the surface of the work. Setting the approach reference point and the exit reference point around the central reference point.

When the image total density percentage exceeds a predetermined percentage, the step of setting the entry reference point and the exit reference point below the surface of the work. -The predetermined percentage is at least 90%. The image data includes first image data and second image data, and the method further comprises the following steps: the total image density of the first image data and the second image data is all of the image data. Determining whether it occupies most of the concentration of -The first image data and the second image data are
Separating the image data subset and the second image data subset. Generating reference points for the first image data subset and the second image data subset.

The image data comprises a plurality of image data sets, the method further comprising the following steps: the total density for the plurality of image data sets accounts for the majority of the density for all image data. The process of determining whether or not. Separating the plurality of image data sets into a plurality of image data subsets. Generating a reference point for the plurality of data subsets.

The curve fitting step further comprises the following steps: Using a cubic spline interpolation method routine during the fitting step. A step of determining the frequency of the image data values representing the engraving area on the work to be engraved in order to generate a predetermined number of density values.

Using a predetermined number of concentration values,
The step of determining the image total density percentage. A step of determining the entry reference point, the exit reference point, and a third reference point between the entry reference point and the exit reference point. A step of determining a tool path using the approach reference point, the exit reference point, and the third reference point.

A step of determining a central reference point corresponding to the center of image density. When the total percentage of image densities exceeds a predetermined percentage, a step of setting the entry reference point and the exit reference point below the surface of the work. -The predetermined percentage is at least 90%. A step of determining whether the image data is continuous tone data or linework data. A step of generating a continuous tone scaler if the image data is determined to be continuous tone data, and a linework scaler if determined to be linework data. Applying the continuous tone scaler or linework scaler to the reference point before the processing step.

Yet another aspect of the present invention is to provide an engraving device for engraving a work, which engraving table and at least one of the works provided on the engraving table. An engraving head having a tool for engraving one engraving area; processing means connected to the engraving head for receiving image data and generating an engraving signal for engraving the at least one engraving area; A digital tool path planning device connected to a processing means for planning a tool path corresponding to the image data, wherein the processing means uses the tool path to generate the engraving signal. Characterize.

Still another object of the present invention is to provide an engraving apparatus provided with one or more of the following additional or optional configurations. A tool path data signal processing device for receiving digital image data corresponding to an image to be engraved and generating the tool path in response thereto.・ Receive image data corresponding to the image to be engraved,
A tool path data signal processing device for generating a plurality of reference points accordingly. A curve fitting device that receives a plurality of reference points and applies to them a curve defining the tool path. A curve fitting device that receives a plurality of reference points and applies to them a curve defining the tool path.

The plurality of reference points are an entry point at which the tool starts engraving the at least one engraving area, an exit point at which the tool exits the at least one engraving area, and an entry point and an exit point. Corresponds to the third reference point in between. -The third reference point includes a center point corresponding to the center of density of the image data. The processing device processes the image data to generate a predetermined number of density values, and the processing device further receives the predetermined number of density values to calculate an image total density percentage. An image density determination device for determining is provided. The processor further comprises concentration center determining means for receiving the predetermined number of concentration values and using these to determine the concentration center.

The processing device receives the image data, determines an image total density percentage, and uses the image total density percentage to generate a plurality of reference points for defining the tool path. The tool path data signal processing device determines the entry reference point and the exit reference point on the surface of the work under a predetermined condition. -The predetermined condition is a concentration smaller than a predetermined concentration. -The predetermined concentration is less than 90%.

The image data includes first image data and second image data, and the processing device further has a total image density of the first image data and the second image data that is a majority of all densities of the image data. A dual frequency determining device for determining whether the first image data and the second image data are separated when the image density exceeds a majority. , First
An image data subset and a second image data subset are generated, and a reference point for each of the first image data subset and the second image data subset is generated. The curve fitting device further uses a cubic spline interpolation routine to generate the tool curve.

Yet another object of the present invention is to provide a method of generating an engraving signal for controlling an engraving head such that a tool of the engraving head moves in a desired tool path. A step of generating an engraving signal, and a step of processing the engraving signal so that the frequency response of the engraving head has a substantially constant gain at a frequency equal to or lower than a predetermined frequency. To do.

Yet another object of the present invention is to provide a method of generating an engraving signal for controlling an engraving head, which comprises one or more of the following additional or optional configurations: -Processing the engraved signal to obtain a signal having a substantially constant gain at frequencies below 10 kHz. -This method further comprises the following steps. The step of performing the treatment step using at least one filter for canceling the natural resonance of the engraving head.

This method further comprises the following steps. Applying at least one enhancement filter to the engraving head to increase the responsiveness of the engraving head in the frequency range above the enhancement frequency but below a predetermined frequency. -This method further comprises the following steps. The step of performing the treatment step using at least one filter for canceling the natural resonance of the engraving head. The enhancement frequency is at least 10 kHz.・
The at least one filter is an indefinite impulse response filter. -The said emphasis filter is an indefinite impulse response filter.

The production step further includes the following steps. A step of generating image data corresponding to the image to be engraved. A step of generating a plurality of reference points corresponding to the image data. A step of determining a tool path using the reference point. A step of generating an engraving signal using the reference points.

This method further comprises the following steps. -Determining at least one parameter associated with the at least one filter using a user interface.

Yet another object of the present invention is to provide an engraving head tuning device for tuning an engraving head so that the tool of the engraving head passes through a desired tool path, which receives an engraving signal, And a processing unit for processing the engraving signal so that the frequency response of the engraving head has a substantially constant gain at a frequency equal to or lower than a predetermined frequency.

Yet another object of the present invention is to provide an engraving head tuning device having one or more of the following additional or optional configurations: The engraved signal is processed to obtain a processed signal having a substantially constant gain at frequencies below 10 kHz. The engraving head tuning device comprises at least one filter for canceling the natural resonance of the engraving head. The engraving head tuning device comprises at least one enhancement filter which enhances the response of the engraving head in the frequency range above the enhancement frequency but below a predetermined frequency. -The enhancement frequency is at least 1 kHz. -The at least one filter comprises an indeterminate impulse response filter. -The said emphasis filter has an indefinite impulse response filter. Each of the at least one filter or the enhancement filter has an indefinite impulse response filter.

The engraving head tuning device is connected to a tool path digital processing device, and the tool path digital processing device has the following configuration.・ Receive image data corresponding to the image to be engraved,
A reference point generation device that generates a plurality of reference points correspondingly. An interpolation circuit that receives the reference point and correspondingly generates the engraving signal.

The engraving head further comprises a speed sensor for detecting the position of the cutting tool for engraving the cylinder. The engraving head further comprises an armature for holding the cutting tool. -The speed sensor further includes the following configuration. A sensing coil arranged around the at least one electromagnetic drive. A detection circuit connected to the detection coil for measuring the speed of the armature and converting the speed into the cutting tool position.

Another object of the present invention is to provide an engraving device for engraving at least one engraving area, the engraving device having an engraving table and a tool provided on the engraving table. The engraving head tuning device is connected to the engraving head and processes an engraving signal. The engraving head tuning device substantially constants the frequency response of the engraving head at a frequency equal to or lower than a predetermined frequency. The engraving signal is processed so that the gain becomes.

Yet another object of the present invention is to provide an engraving head tuning device having one or more of the following additional or optional configurations: The engraved signal is processed to obtain a processed signal having a substantially constant gain at frequencies below 10 kHz. The engraving head tuning device comprises at least one filter for canceling the natural resonance of the engraving head. The engraving head tuning device comprises at least one enhancement filter for increasing the engraving signal in a frequency range above the enhancement frequency but below a predetermined frequency. The engraving head tuning device further comprises at least one filter for canceling the natural resonance of the engraving head. The engraving head tuning device further comprises at least one enhancement filter for increasing the engraving signal in a frequency range above the enhancement frequency but below a predetermined frequency. -The enhancement frequency is at least 1 kHz. -The at least one filter comprises an indeterminate impulse response filter. -The said emphasis filter has an indefinite impulse response filter. -The at least one filter and the enhancement filter each have an indefinite impulse response filter.

The engraving head tuning device is connected to a tool path digital signal processing device, which receives image data corresponding to the image to be engraved and which corresponds to a plurality of reference points. And a interpolation circuit that receives the reference points and correspondingly generates the engraving signals.

The at least one enhancement filter has at least one parameter for an engraving head tuning device, and further comprises a filtering device connected to the at least one enhancement filter, the filtering device comprising: , A user interface for programming the at least one parameter associated with the enhancement filter.

The at least one enhancement filter has at least one parameter for an engraving head tuning device, and further comprises a filtering device connected to the at least one filter, the filtering device comprising: A user interface is provided for programming the at least one parameter associated with the at least one filter.

The engraving head further comprises a speed sensor for detecting the position of the cutting tool for engraving the cylinder. The engraving head further comprises an armature for holding a cutting tool, and at least one electromagnetic drive device having at least one drive coil for vibrating the armature when energized, and the speed sensor, A detection coil arranged around the at least one electromagnetic drive device, and connected to the detection coil,
A sensing circuit for measuring the speed of the armature and converting the speed to the cutting tool position.

Yet another object of the present invention is to provide a method of tuning an engraving head, the method comprising:
Filtering the engraving signal to eliminate unwanted resonances using at least one filter,
Defining a filter constant for the at least one filter, connecting a user interface to the at least one filter, determining whether at least one parameter of the at least one filter needs to be changed, and Programmably adjusting the at least one parameter using the user interface if the one parameter needs to be changed.

Still another object of the present invention is to provide an engraving head tuning method having one or more of the following additional or optional configurations: There is the step of determining if the frequency or notch depth needs to be changed. • At least one parameter is frequency. • At least one parameter is notch depth. -The method further comprises the step of connecting a processing device to the at least one filter. -Adjusting the at least one parameter automatically using a processor in response to a request for automatic tuning. -Using a user interface to programmably adjust at least one parameter and set at least one filter to obtain a substantially constant gain in a frequency range below a predetermined frequency. The predetermined frequency is less than 10 kHz.

The method further comprises the following steps: Using a user interface to adjust at least one parameter of the at least one enhancement filter, and the response of the engraving head in the frequency range above a predetermined enhancement frequency. Increasing. The enhancement frequency is at least 1 kHz. -The at least one filter is an indeterminate impulse response filter. The step of automatically adjusting further comprises the following steps or configurations: -Using a sensor to detect the position of the cutting tool for engraving the cylinder. -The step of automatically adjusting is performed by using the detected position of the cutting tool. -The sensor is a speed sensor.

The method further comprises the steps of: placing a sensing coil around the at least one electromagnetic drive on the engraving head: and connecting a sensing circuit to the sensing coil, The process of measuring the speed and converting it to the position of the cutting tool.

Yet another object of the present invention is to provide an engraving apparatus, which comprises an engraving table, an engraving head having a tool provided on the engraving table, and an engraving head provided on the engraving head. At least one filter having at least one parameter and at least one filter coefficient, and a user interface connected to the at least one filter, the user interface for changing a response characteristic of the filter. At least one parameter is programmable and adjustable.

Still another object of the present invention is to provide the engraving apparatus provided with one or more of the following additional or optional configurations: -The at least one parameter is frequency. Or notch depth. -The at least one parameter is frequency. -The at least one parameter is notch depth. The engraving device further comprises a processing device connected between the user interface and the at least one filter, the processing device automatically adjusting the at least one parameter in response to an automatic tuning request. A means for adjusting is provided.

The user interface may include the at least one filter so as to define a response characteristic of the engraving head so that a substantially constant gain is obtained in a frequency range lower than a predetermined frequency. Means for programmable adjustment of at least one parameter of the two filters. The predetermined frequency is less than 10 kHz. The user interface comprises means for adjusting at least one parameter of at least one enhancement filter associated with the engraving filter to increase the responsiveness of the engraving head in the frequency range above a predetermined enhancement frequency. The enhancement frequency is at least 1 kHz. -The at least one filter comprises an indeterminate impulse response filter.

The means comprises an indefinite impulse response filter connected to the interactive user interface. The engraving head further comprises a speed sensor for detecting the position of the cutting tool for engraving the cylinder. The engraving head further comprises an armature for holding a cutting tool, and at least one electromagnetic drive device having at least one drive coil for vibrating the armature when energized, and the speed sensor, A detection coil arranged around the at least one electromagnetic drive device, and connected to the detection coil,
A sensing circuit for measuring the speed of the armature and converting the speed to the cutting tool position.

Yet another object of the present invention is to provide a method of stabilizing an engraving head comprising a motor for driving a cutting tool, the method comprising: Supplying a drive signal of 1;
The method includes detecting the speed of the motor using a second coil, and stabilizing the engraving head using the motor speed.

Still another object of the present invention is to provide the above method, which comprises one or more of the following additional or optional configurations: The second coil of the motor. With less than 5 windings arranged around it. The method further comprises detecting the actual position of the cutting tool using the sensed cutting tool position, the motor speed, and the first drive signal to achieve the stabilization. .

Still another object of the present invention is an engraving device for engraving at least one engraving area, which has an engraving table, a cutting tool provided on the engraving table, and an armature holding the cutting tool. Energizing the engraving head, and a head tuning device connected to the engraving head for processing the engraving signal so that the frequency response of the engraving head has a substantially constant gain at a frequency equal to or lower than a predetermined frequency. And at least one electromagnetic drive having at least one drive coil for vibrating the armature according to claim 1, and a sensor provided in association with the at least one electromagnetic drive for determining the speed of the electromagnetic drive. The head tuning device tunes the engraving head resonance in response to the speed and the processed signal. .

Still another object of the present invention is to provide the engraving device having one or more of the following additional or optional configurations: -The sensor is the at least one of the at least one. A sensing coil is provided around the electromagnetic driver. A detection circuit connected to the detection coil for measuring the speed of the armature and converting the speed into the position of the cutting tool. The sensing coil measures the rate of change of the magnetic flux density passing through at least one drive coil. The sensing coil has no more than 5 windings for the electromagnetic driver. The engraving head tuner processes the engraving signal to produce a processed signal having a frequency response with substantially constant gain in the frequency range below 10 kHz. The engraving head tuner comprises at least one filter for canceling the natural resonance of the engraving head. The engraving head tuner includes at least one emphasis filter that amplifies an engraving signal in a frequency range lower than a predetermined frequency and higher than the emphasis frequency.

The engraving head tuner further comprises at least one filter for canceling the natural resonance of the engraving head. The engraving head tuner comprises at least one enhancement filter that amplifies the engraving signal in a frequency range lower than a predetermined frequency and higher than the enhancement frequency. The enhancement frequency is at least 1 kHz. -The at least one filter comprises an indeterminate impulse response filter. The enhancement filter comprises an indeterminate impulse response filter. The at least one filter and the enhancement filter each comprise an indefinite impulse response filter. The engraving head tuning device is connected to a tool path digital signal processing device, which receives image data corresponding to the image to be engraved and correspondingly generates a plurality of reference points It comprises a reference point generation device and an interpolation circuit for receiving the reference point and correspondingly generating the engraving signal.

Still another object of the present invention is a method for scaling (standardizing, scaling) image data to be engraved, which method generates image data corresponding to the image to be engraved. A step of determining whether the image data is continuous tone data or linework data, and a step of determining if the image data is continuous tone data or linework data, respectively. Generating a gradation reference point or a linework reference point.

Yet another object of the present invention is to provide said method comprising one or more of the following additional or optional arrangements: -Processing said reference point and tool path And the process of creating
Driving the tool in response to the tool path to engrave a work. The method further includes the step of generating a continuous tone reference point or a linework reference point, respectively, when the image data is determined to be continuous tone data or linework data in the determination step. It is equipped with.

Still another object of the present invention is to provide an engraving device for engraving a work, which engraving table and at least one of the works provided on the engraving table. An engraving head having a tool for engraving one engraving area; a processing device connected to the engraving head for receiving image data and generating an engraving signal for engraving the at least one engraving area; A digital tool path planning device connected to a processing device for planning a tool path corresponding to the image data, wherein the processing device uses the tool path to generate the engraving signal. Characterize.

Further, another object of the present invention is to provide the engraving apparatus provided with one or more of the following additional or optional constitutions: The processing apparatus further engraves A tool path data signal processing device is provided for receiving digital image data corresponding to a power image and generating a tool path in response thereto. The tool path data signal processing device determines scaling means for scaling (standardizing, enlarging / reducing) the image data to be engraved, and whether the image data is continuous tone data or linework data. And a reference point generation means for generating a continuous tone reference point or a linework reference point, respectively, when the image data is determined to be continuous tone data or linework data.

The tool path data signal processing device is
Further, there is provided scaling means for processing the reference point to determine a tool path and determining the tool path, and for driving the engraving head so as to engrave the work corresponding to the tool path. -The scaling means, in the determination step,
When it is determined that the image data is continuous tone data or linework data, a continuous tone reference point or linework reference point is generated, respectively.

Other objects and advantages of the invention will be apparent from the following description and claims using the drawings.

[0076]

1 is a perspective view showing an engraving apparatus 10 as a preferred embodiment of the present invention. In this embodiment, the engraving device 10 is a gravure engraving device, but the invention is also applicable to other types of engraving devices. The engraving device 10 is not shown for simplification,
It is housed in a sliding safety cabinet. The engraving device 10 comprises a base 12, which is
A headstock 14 and a tailstock 16 are provided, which are track 1
8 are mounted so as to be movable toward and away from each other. The engraving device 10 includes a plurality of linear actuators (first drive motor means or first drive motor) 2
0, and second drive motor means or second drive motor)
The motors 20, 22 drive the headstock 14 and the tailstock 16 in the directions in which they approach and separate from each other. For example, by these motors, the headstock 14 and the tailstock 16 are moved from the position supporting the cylinder to the position where they are closest to each other as shown in FIG.

The drive motors 20 and 22 may be independently supplied with electric power so that the headstock 14 and the tailstock 16 can be driven separately or simultaneously. As the drive motor, a motor having a single lead screw (not shown) may be used, and in that case, screws opposite to each other may be formed on both end sides of the lead screw. In this case, when the lead screw is rotated, the headstock 14 and the tailstock 16 simultaneously move in opposite directions. Headstock 14
When both the tailstock 16 and the tailstock 16 are moved, the cylinders 24 having different lengths can be mounted by using an elevated crane, for example, by moving them in a direction perpendicular to the rotation axis of the cylinder 24. However, it is also possible to make one of the headstock 14 and the tailstock 16 fixed and move the other, in which case the cylinder 24 is moved in a direction parallel to the rotation axis of the engraving apparatus 10. Use a cylinder mounting mechanism that can.

As shown in FIG. 1, the cylinder 24 has a first
It has an end part 24b and a second end part 24c, and receiving holes (not shown) are formed in these end parts, and the tip parts 14a, 14b of the headstock 14 and tailstock 16 are inserted into these receiving holes. There is. Generally, the tip portions 14a and 14b are formed in a conical shape, and the receiving hole of the cylinder 24 also has a corresponding shape, so that the cylinder 24 is supported at the position of the engraving station 26 of the engraving apparatus 10. . Although not shown, when engraving a cylinder with a shaft, the headstock 14 and tailstock 1
At 6, a gripping device or chuck for rotatably supporting the cylinder is provided.

The engraving apparatus 10 also includes an engraving head 28, which is provided with a cutting tool or a cutter needle (engraving needle) 30 for engraving the outer peripheral surface 24a of the cylinder 24. In the embodiment of the gravure engraving apparatus, the outer peripheral surface 24a is preferably coated with copper, but the invention is not limited thereto. The engraving head 28 is slidably mounted on a movable table 32, and the engraving head 28 is moved toward and away from the cylinder 24 in the cylinder radial direction by a third drive means or a third drive motor 27. The movable table 32 is movably attached to the base 12 and extends over the entire length of the surface 24 a of the cylinder 24.
The engraving head 28 can be moved as indicated by the middle arrow 36. In this case, the moving direction of the movable table 32 coincides with the axial direction of the cylinder 24. Engraving device 10
Has a lead screw and a drive motor for moving the movable table 32 in the direction of arrow 36 (both not shown). US Pat. No. 5,424,845 assigned to the applicant;
5,424,846; 5,438,422; 5,440,398; 5,454,306
Nos. 5,492,057; 5,329,215, respectively, and various configurations are also applicable to the present invention, and these configurations are incorporated into the present specification and constitute a part of the present specification.

The engraving apparatus 10 also comprises a drive means or a drive motor 11, which, when energized by the engraving controller 38, causes the support shaft 14a to rotate and the cylinder 24 to rotate. The engraving device 10 includes an engraving control device 38. The engraving control device 38 controls the operation of the engraving device 10 and all the drive motors 1
1, 20, 22, 27 are controlled. Drive motors 11, 2
0, 22, and 27 are individually controlled by the engraving control device 38.

The engraving device 10 further comprises an image processing means or an image processing computer 40, which is connected to the engraving control device 38.
The engraving device 10 is adapted to generate digital image data relating to the image to be engraved / and the engraved image. An example suitable as the image processing computer 40 is an image processing workstation model number IPW-20.
This device is sold by the applicant, Ohio Electronic Engravers, Inc. of Dayton, Ohio.

A feature of the present invention is the provision of a tool path to be followed by the cutter needle 30 for engraving the engraved area to be engraved in response to the stream of digital image data. The engraving device 10 has at least one digital signal processor or processing means (shown as block 42 in FIG. 1) which is connected to the engraving control device 38 for processing image data or signals received from the engraving control device 38. The received signal is filtered and adjusted according to various feedback signals by the method described later. The processing means 42 is also connected to the amplifier 53, amplifies the signal generated by the processing means 42, transmits it to the engraving head 28, and causes the cutter needle 30 to engrave a pattern in the engraving area of the surface 24a of the cylinder 24. To drive.

As shown in FIG. 2, the digital signal processing device 42 comprises tool path means or tool path control device 44, which should be followed by the cutter needle 30 to carry out the engraving. It is designed to generate a tool path.

In general, the processing unit 42 is adapted to generate a plurality of digital control digital reference points, for example, in response to a digital image data stream 60 received from the engraving control unit 38, as shown in FIG. The reference points 62a-62i as shown are generated. As previously mentioned,
The engraving controller 38 is adapted to receive a digital image data stream 60 from an image processing computer 40 (see FIG. 1). A method and apparatus for generating reference points from digital image data and for generating engraving tool paths corresponding to these reference points will be described below with reference to FIGS. 2-6.

As shown in FIG. 2, the processor 42 has a tool path controller 44.
Comprises generator means or generator 46 for receiving digital image data from the engraving controller 38 and generating a plurality of reference points, such as reference points 62a-62i in FIG. The generator 46 receives image data in the form of a digital density value data stream 60. The digital density value is, for example, the density values 60a and 60 shown in FIG.
b ... 60l. For ease of illustration, the density values are shown as percentages, where 0% density indicates a white or non-engraved area and 100% density indicates an engraved area that is completely black.

In this embodiment, the digital density value data stream 60 contains four data values for each region to be engraved. Reference point generator 46
Receives this data value and generates a plurality of reference points 62a-62i (FIG. 3) in response. in this way,
For example, the generator 46 uses the digital image data stream 6
It receives image data values 60a-60d from 0 and correspondingly generates reference points 62a-62c.

The tool path control device 42 is a curve fitting device /
A tool path generator 48 is provided which receives a plurality of reference points 62a-62i and, in response, generates a tool path 64 as shown in FIG. As shown in FIG. 3, the portion 64a of the tool path 64 is generated using generalized reference points 62a-62c. Similarly, portions 64b and 64c of tool path 64 are generated using reference points 62d-62f and reference points 62g-62i, respectively.

In this embodiment, the curve fitting / tool path generator 48 comprises a computing means for the processor 42 resident in a cubic spline interpolator or curve fitting routine or suitable memory (not shown), By this, the reference points, for example, the reference points 62a-62i are received,
Correspondingly, the tool path 64 is generated. In this embodiment, the toolpath generator 48 divides the toolpath 64 into discrete data segments 32. Figure 1 shows one of them
It is shown as 64d inside. These discontinuous data segments 32 eventually become the tuning processor 5 as will be described later.
2 is transferred. In this regard, "Numeric Recipes in
C the Art of Scientific Computing "Second Edition, Cambridge University Press, Section 3.3-" Cubic Spline I "
The curve fitting technique described in "Nterpretation" can be used to fit the curve to the reference point to be processed.

The digital signal processing device 42 and the tool path control device 44 further include a synchronization means or a synchronization routine 50, which receives the machine synchronization signal from the engraving control device 38 and outputs the digital tool path. 64 is synchronized with the rotation of the cylinder 24. Reference point generator 46, tool path generator 4
8 and the operation of the synchronization routine 50 will be described below with reference to FIGS. 6, 7 and 8.

First, in the decision block 80 shown in FIG. 6, the reference point generator 46 sets the data values 60a-60l to four.
It is divided into one group and it is determined whether or not each of the four image data values, for example data values 60a-60d, represents a continuous tone image (CT). In this regard, the image data value 6
0a-60d includes image intensity values and indicators to distinguish the data source as "CT" or "LW". If the decision in decision block 80 is no, the image data passed from the engraving controller 38 to the reference point generator 46 is a linework image (LW).

In block 81, the reference point generator 4
6 selects the appropriate setup value (not shown) used to process the LW image data values. The setup values used in this process are AC gain, DC gain,
And offset value, which is OEE patent 5,42
No. 4,848 and 5,621,533, the contents of which are incorporated herein.
If the decision at decision block 80 is "yes", the image data value is a CT image and the routine proceeds to block 82 to select the CT setup value for use by the fiducial point generator 46.

The routine then proceeds to block 84, where the fiducial point generator 46 determines a plurality of scalers to scale the image data values 60a-60d (FIG. 3).
reference). The reference point generator 46 first uses the CT setup value to determine the maximum cell depth scaler (block 84).
, And the channel depth scaler for CT (block 86) is also calculated using the CT setup value.

Blocks 88 and 9 are shown in FIG.
At 0, the maximum cell depth scaler for the LW and the channel depth scaler for the LW are calculated, respectively.

After blocks 86 and 90, the routine proceeds to block 92 where fiducial point generator 46 calculates the total density percentage of the sum of the four image data values. In decision block 94, if the total density percentage is less than 1%, it is determined to be a non-engraving area. If so, the routine proceeds to block 96 where the fiducial point generator 46 causes the cylinder 2 to move while the cutter needle 30 is actually engraving.
A reference point is assigned so as to be located above the surface 24a of No. 4 and stored. The routine is then complete.

If the decision at block 94 is no, then the routine proceeds to decision block 98 shown in FIG.
It is determined whether multi-frequency cells or engraving areas are required. In this embodiment, in block 98, the first data value is greater than the sum of the second and third data values (eg, 60a> (60b + 60c)) and the fourth data value is the second and third data values. Greater than the sum of (for example, 60d> (60b + 60
In c)), the determination of multiple frequencies becomes “yes”.

FIG. 4 shows another data stream 66, which comprises a plurality of density values 66a-
Includes 66l. In the example shown in FIG. 4, the density value 6
6e-66h shows the density value changing from black (100%) to white (0%) and then to black (100%), 66e>
Since (66f + 66g) and 66h> (66f + 66g), the multi-frequency engraving area is shown. The engraved area represented by these density values has density values 66a-66.
Shown as engraved areas 65a and 65b defined by the toolpath 65 generated with 1. Figure 4
The process for generating the tool path 65, which is the multiple engraving area shown in, will be described below.

If the decision at decision block 98 in FIG. 7 is "no", then no multi-frequency engraving region is required and the routine proceeds to block 100 to determine the entry reference point or position and depth. In this regard, an approach reference point, such as point 62a in FIG. 3, is determined and the appropriate CT or LW channel scaler is applied to the first image data, which is 60a in this case, to determine the approach depth (Ed in FIG. 3). ) Is determined. This depth Ed is the depth at which the cutter needle 30 penetrates the cylinder surface 24a.
Similarly, in block 102, the center point position 62b and the center point depth (Cd in FIG. 3) are determined. The center point depth Cd is determined by applying the maximum depth scaler to the previously calculated total% concentration (block 1 in FIG. 7).
02). The center point position is determined by calculating the center of the image densities of the image data values 60a-60d and setting the reference point 62b so that the same amount of density comes to the right and left thereof. In this way, the center of the engraved cell is shifted towards the darker image data values, enhancing the quality of the reproduced image. This feature is the engraving area 75 of FIG.
And reference points 71a-71c therein are shown for comparison. The routine proceeds to block 104 where the escape reference point position (shown at point 62c in FIG. 3) and the escape reference point depth Exd are determined at block 104. afterwards,
The routine is complete.

If a multi-frequency engraving area is requested, the decision at decision block 98 will be "yes". The routine proceeds to block 106 where reference point generator 46 points 70 for the first subset of image data values 66e and 66f.
While generating reference points such as a, 70b and 70c, reference points 70d, 70e and 70f are generated for the second image data subset represented by the density values 66g and 66h.

As shown in FIG. 4, the routine splits the image data value stream 66 into a subset of four data values representing multiple engraved areas. In the example shown in FIG. 4, the area 6
A tool path 65 is finally created to engrave the double or double frequency engraving area, as shown at 5a and 65b. The operations and procedures for processing multi-frequency data values are described below.

In block 106 of FIG. 7, fiducial point generator 46 calculates a total density for the first pair of data values, such as data values 66e and 66f shown in FIG. The routine proceeds to block 108 where fiducial point generator 46 determines the center of image density for this first pair of data values. At block 110, reference point generator 46 then determines the location of the first approach reference point, such as reference point 70a of FIG. 4, and its approach depth. The depth of the first entry point is determined by using the first data value 66e and applying a channel depth scaler to it. At block 112, the reference point generator 46 determines the first center point position (point 70b in FIG. 4) and depth. The first center point 70b is centered on the image density and its depth is determined by the maximum depth scaler of the first pair of data values 66e and 6e.
Set by applying to the total concentration percentage for 6f. At block 114, the first escape position (point 70c) and its depth are determined.

The cutter needle 30 escapes from the surface 24a at the escape point 70c. The point 70c is located at a distance D1 (see FIG. 4) from the start point SP. This distance D1 corresponds to the overall length D2 and corresponds to the block 10 of FIG.
Vary at the same rate as the total concentration percentage calculated in 6.

Reference point generator 46 then determines reference points 70d-70f based on the second image data value subset (values 66g and 66h shown in FIG. 4). Therefore, in block 116 of FIG.
6 determines the total concentration for the second pair of data values 66g and 66h. At block 118, the reference point generator 46 determines the center point of image density for the second image data subset. At block 120, the location and depth of the second entry reference point (point 70d in FIG. 4) is determined. The cutter needle 30 enters the surface 24a at the entry reference point 70d. This point 70d is a position separated from the escape point EP by a distance D3. This distance D3 varies in proportion to the total length D2 in the same proportion as the total concentration percentage calculated in block 116 of FIG.

The routine then proceeds to block 122 shown in FIG.
Then, the position and depth of the second central reference point (point 70e) are determined. The second center reference point 70e (FIG. 4) is set at the center of the image density of the second pair of data values 66g and 66h. The depth of the second center point is determined for the second pair of data values 66g and 66h by the maximum depth scaler (block 84 for CT data, LW
Data (determined at block 88) is applied to the total concentration percentage (see block 116 of FIG. 7). At block 124, the second escape position (point 70f) and its depth are determined. The depth of the second escape point 70f is the last data value 66
It is determined by using h and applying the channel data scaler (block 86 or 90 in FIG. 6).

Once all the reference points 70a-70f have been generated by the reference point generator 46, they are transferred to the curve fitting / tool path generator 48, which is in memory, for example a reference point buffer. The reference points 70a-70f stored in (not shown) are processed. Reference point generator 46 interpolates or fits the curves corresponding to reference points 70a-70f to generate a tool path, such as tool path 65 shown in FIG. The tool path 65 is stored in a memory such as an output buffer (not shown) and is used to generate an engraving drive signal for driving the engraving head 28.

The digital signal processor 42 also comprises the aforementioned synchronization means or synchronization routine 50, which receives the synchronization signal from the engraving controller 38 and produces the generated tool path, for example the tool path. 64
Or 65 is made to synchronize. The synchronization routine 50 will be described with reference to FIG. The synchronization routine 50 begins at block 126 by first reading a portion of the tool path 64, for example portion 64d (see FIG. 3).

The routine transfers the generated toolpath to the tuning processor 52 (FIG. 2) for use in the manner described below (block 128 of FIG. 8).

The routine also collects the received image data stream 60 and begins the generation of, for example, a tool path 64. The routine is executed from the engraving controller 38, for example, the area 6
For each single frequency engraving area such as 7, image data 60 is received for every 4 data values, such as values 60a-60d in FIG. At substantially the same time, the routine provides data for toolpath 64 to 32 data values or segments (eg, segment 64 in FIG. 3) for each single frequency engraved region (eg, region 67 in FIG. 3).
It is transferred to the tuning processor 52 for each d).

The routine then proceeds to block 13 shown in FIG.
Proceeding to 0, the digital image data stream 60 as shown in FIG. 3 receives four data values (ie 60a-60d) from the engraving controller 38 for each single frequency engraving region. Further, image data, such as 60a-60d, is stored in a suitable memory of the toolpath controller 44.

At decision block 134, it is determined whether four image data values, such as the values 60a-60d shown in FIG. 3, have been received by the tool path controller 44. If not, the routine is complete. If an image data value is received,
The routine proceeds to block 136 shown in FIG. 8 where the reference point generator 46 generates reference points 62a-62c from the image data values 60a-60d in the manner described in FIGS.

At block 138, a tool path, such as tool path 64 shown in FIG. 3, is further calculated from the reference point by the tool path generator 48 described above. afterwards,
The synchronization routine or means is complete and the toolpath is synchronized with the operation of the engraving device 10.

Advantageously, the present invention allows the digital image data stream 60 and traditional screening functions to be combined into a reference toolpath or waveform that represents the toolpath to be followed by the cutter needle 30. Since the conventionally used screening is directly synthesized from the digital image data, it is possible to improve print quality and flexibility.

In this embodiment, the image data is converted into the above-mentioned reference point, the entry point where the cutter needle 30 enters (point 62a in FIG. 3), and the point where the maximum depth is reached (FIG. 3).
62b) and the escape point (point 62c in FIG. 3)
Is determined for each area to be engraved (such as area 67 in FIG. 3). As already mentioned, the reference points are later used by the curve fitting / tool path generator 48, which defines a tool path 64, such as the tool path 64, which engrave path to be followed by the cutter needle 30. Generate, interpolate, or fit a path. As a result, the tool path 64 is generated directly from the digital image data and used as the path of the cutter needle 30.

Another feature of the present invention is that the method and apparatus of the present invention facilitates digitally distorting the generated toolpath. For example, one or more centers of the engraved area or partially engraved area,
In particular, it can be shifted in the peripheral portion of the image (not shown). Therefore, as shown in FIG.
9a-69d shows the densities of 100% (pure black), 100 (pure black), 0%, and 0%. In many past engraving systems, these densities were averaged and a 50% density cell (not shown) was generated in the center of the area 74.

On the other hand, the reference point generator 46 of the present invention is used.
Now, the image data is evaluated and corresponding reference points 71a-71c as shown are generated. These reference points 71a-
71 c is a tool path curve 73 generated by the tool path generator 48.
Used to generate.

Therefore, the tool path defines the engraved area 75 deviated from the center, which corresponds more accurately to the originally input image data 69a and 69b.

This feature facilitates enhancing the quality of the engraved image. For example, FIG. 19 shows a Chinese character pattern X engraved by a general engraving technique.
On the other hand, FIG. 18 shows a Chinese character pattern Y engraved using the apparatus and method of the present invention. Comparing the horizontal lines X1 and Y1 in each figure, it can be seen that the engraving area, which was placed in X2 in the prior art, is displaced, and the engraving quality is improved.

The present invention further includes the tuning means, tuning processor, tuning device or tuning system 52 (see FIG. 2) and engraving head 28 so that engraving head 28 follows the correct tool path as required. A method of calibrating or tuning is provided. The tuning device 52 is connected to the engraving head 28 via an amplifier 53, which is a tuning device 52.
The engraving signal received from the amplifier is amplified, and the cutter needle 30 provided on the engraving head 28 is driven.

FIG. 11 shows an unprocessed engraving head response characteristic 5
3, indicating that a plurality of peaks have occurred. These peaks 53 a and 53 b are the first and second peaks of the engraving head 28.
It is due to the resonance of. As is known in the art, in a general engraving head 28, the first and second resonances are usually near 1800 kHz and 5500 kHz.
It occurs in the vicinity respectively. Further, as is conventionally known, as shown in FIG. 12, in a general engraving system, a plurality of notch filters are provided on the engraving head 28 so as to eliminate the first and second resonances and smooth the resonance. Although the response characteristic 57 is obtained, the response characteristic 57 decreases substantially continuously as shown in FIG.

Advantageously, the apparatus and method of the present invention comprises an enhancement filtering means or enhancement filter 5.
6 is provided, a substantially constant gain or a linear response characteristic can be obtained as shown by the response characteristic 58 in FIG. The response characteristic 58 is substantially constant up to a frequency around 10,000 kHz, and is linear over a wider range. In general, the apparatus and method of the present invention comprises
This embodiment achieves the aforementioned objectives by increasing the engraving signal at frequencies above the enhancement frequency which is at least 1 kHz.

In order to obtain the response characteristic as shown in FIG. 13, the tuning processor 52 is provided with at least one or two or more filters 54 and 56, which are the tool paths generated by the tool path controller 42 (see FIG. In 3, the tool path 64) is processed or filtered. Notch filter 54
After processing the tool path 64 to eliminate the first and second resonances, the enhancement filter 56 processes the signal and transforms it into a response characteristic 58 as shown in FIG.

In this embodiment, the notch filtering may be performed by a single indefinite impulse response filter algorithm, which may be the One Technology Way, PO Box.
9106, Norwood, MA 02062, Analog Devices, Inc.
It can be run on a digital signal processor such as the company's "ADSP21062". A second indeterminate impulse of the response filter may be provided to perform the enhanced filtering of the present invention. An algorithm that can be used to perform the notch and enhancement filtering performed by filters 54 and 56 is the Indeterminate Impulse Response (IIR) 4th order filter, which is located in Analog Devices, I., Norwood, MA.
nc.'s analog device “ADSP-21000 Application Ha
ndbook ", Volume 1, published in May 1994, Section 4.2-IIR Filters.

Once the notch filter 54 has converted the response curve to the desired response characteristic, the enhancement filter 56 is set to
As shown in response curve 58 of No. 3, a substantially linear or flat frequency response should be provided, in which case engraving head 28 will have the same amplitude over a wide frequency range. This is especially the case of the type 2 described with reference to FIG.
There are benefits when engraving or forming double frequency engraving areas. Because of the filtered engraving head 2
8 is because at the frequency of 10 kHz as shown, at least 50% of the maximum amplitude must be possible.

In this embodiment, the tuning means 52 further comprises a tuning computer, interface means or user interface 150 (see FIG. 2), constituting a notch filter 54 and an enhancement filter 56. The interface 150 may include an IBM or IBM compatible PC running application software that creates an interactive interface screen 150a as shown in FIG. In this regard,
User interface screen 150a may include a window 150b for entering or adjusting parameters for notch filter 54 and enhancement filter 56. In this embodiment, the filter parameter is the frequency value 1 for the notch filter 54.
52 and notch depth value 154. On the same user interface screen (not shown), the central filter parameter value for the emphasis filter 56 can be input. In this embodiment, FIG.
The user interface 150 of the above converts the parameter information into a filter constant using the following coefficient formula. C ₁ = 2COS (0.000005 * 2 * π * FREQ * 1-DAMP ² ) * _e (-0.0000
05 * 2 * π * FREQ * DAMP) C ₂ = ( _e (-0.000005 * 2 * π * FREQ * DAMP)) ²

Here, C ₁ and C ₂ are the coefficients of the IIR filter used in the notch filter 54 and the enhancement filter 56, and FREQ is the frequency value input to the user via the user interface 150 of FIG. Where DAMP is the attenuation value of the filters 54, 56 input to the user via the user interface 150, and π is the universal constant 3.14159.

The calculated coefficients C ₁ and C ₂ are used to electrically set or adjust the actual coefficients of the filters 54, 56. Advantageously, the present invention allows a user to interactively adjust or set the filter count value, without changing the hardware such as the filters provided on the engraving head 28.
It is possible to electrically program or change the frequency characteristics of the.

The engraving apparatus 10 further stabilizes the engraving head 28 by electrically attenuating the original resonance of the engraving head 28, thereby enabling the engraving head 28 to be stabilized by a digital closed loop feedback means or a feedback controller 156 (FIG. 2). ) Is provided. In this embodiment, the feedback controller 156 includes a sensor circuit 158.
This sensor circuit 158 is connected to (FIG. 16) and detects the position and speed of the cutter needle 30 and sends it to the feedback control device 156 (FIG. 2).

In this regard, FIG. 15 shows a cross-sectional view of a typical armature (armature) 170.
0 is firmly fixed to the shaft 172, and a pair of electromagnets 1
An electromagnet 174 is mounted in the base of the engraving head 28, projecting outwardly between 74. Such a structure is shown, for example, in US Pat. No. 5,029,011, US Pat. No. 4,4, assigned to the same assignee as the present invention.
50,486, U.S. Pat. No. 4,438,460, U.S. Pat. No. 4,357,633, the disclosures of which are incorporated herein. A space 176 is formed between the armature 170 and the electromagnet 174. As is well known, when the electromagnet 174 is supplied with an alternating current, the armature 170 and the shaft 172 move along an arc having a central angle of about 0.25 °, for example, a frequency of 3-5.
It vibrates at kHz. Also, as is well known, the cutter needle 3
0 is fixed to the shaft 172 via a support arm (not shown), and vibrates as the shaft 172 vibrates. The excitation of the electromagnet 174 is performed by the winding 178 as is well known.

The sensor circuit 158 has a second winding 180 wound around an electromagnet 174. In this embodiment, the windings 180 include coils for measuring the magnetic flux density in the electromagnets of the armature 170, the output of which is used by the feedback controller 156 to calculate the actual position of the cutter needle 30. The magnetic flux density in the electromagnet 174 is 2
The sum of the magnetic flux from one source, that is, the magnetic flux from the drive winding 178 and the magnetic flux generated by the movement of the armature 170. By subtracting the magnetic flux density of the winding 178 from the magnetic flux density existing in the motor and the electric circuit (circuit 158 of FIG. 16) detected by the winding 180, the armature 17
A component of magnetic flux density with a velocity of 0 is obtained.

The means or circuit 158 comprises a current sensing resistor 182 disposed between the low side of engraving head 28 and ground as shown. Circuit 158 also includes a receive amplifier 184 connected to the high terminal (+) 178a and the low terminal (-) 178b of the head drive winding,
The signal amplified by this is further inverted by the inverting integration amplifier 1
Integrated by 86. The integrated signal is transmitted to one of the inputs of summing amplifier 188 as shown in FIG.

The circuit 158 also includes a high side (+) 180a and a low side (-) of the head sensor as shown in FIG.
A receiving amplifier 190 connected to 180b, and a current sensor resistor 182 connected in parallel therewith (FIG. 16).
It is equipped with. Receive amplifier 190 receives the measured signal and outputs an amplified output signal that is provided to a second input of summing amplifier 188 and a single input of differential amplifier 192.

Differentiating amplifier 192 and receiving amplifier 184
The outputs of the above are supplied to the summing amplifier 194. Summing amplifiers 188 and 194 sum the inputs provided to them and generate and output a position signal and a velocity signal, respectively. The position and velocity signals have been found to correlate with the position and velocity of the armature 170 and the cutter needle 30.

These detected signals are fed back to the user interface decoder 154 (FIG. 2). The interface decoder 154 provides the engraving head 28 response data to the user via the user interface 150 as described above.

The system and method of the present invention includes means for interactively and automatically tuning the engraving head 28, which means will be described with reference to FIGS. The routine begins at block 200
First, the tuning processor 52 receives from the tool path controller 42 the most recently transmitted value for the tool path 64. The routine then proceeds to block 202 where the tool path values are processed by the notch filter 54 using the tuned filter coefficients. The tuning filter coefficient may be a predetermined coefficient or a filter coefficient generated according to a parameter input by a user through the user interface 150.
It was generated by.

At block 204, the tool path value is
Processing is performed by the emphasis filter 56 using the emphasis filter coefficient. The emphasis filter coefficient is generated by the user interface 150 using a predetermined coefficient or a filter coefficient generated according to a parameter input by the user through the user interface 150.

At decision block 206, it is determined whether the user has entered a tuning parameter update request by entering new or different parameters using the user interface 150a, and if so, then: The new filter coefficients generated by the user interface 150 are recorded by the tuning processor 52 in an appropriate buffer not shown (block 209 in FIG. 9).

If the determination at block 206 is no, then the routine proceeds to block 208 where the user has entered new enhancement filter parameters, thereby requesting an update of the enhancement filter 56. Is determined. If requested,
The routine proceeds to block 210 where the new enhancement filter coefficients generated by the user interface 150 are stored by the tuning processor 140 in an appropriate buffer (not shown).

If the decision at decision block 208 is negative, the routine continues to block 212, where it is determined if a head response test request from the user interface 150 has been received by the interface decoder 154. To be done. If so, the routine begins testing the engraving head 28 with the test pattern sent to the engraving head 28. During such a test, the feedback controller / means 156 detects or feeds back information regarding the actual position and speed of the cutter needle 30 in the manner described above. The sensed position and velocity are fed back to the interface decoder 154 and thus the user interface 150. The method will be described below with reference to FIG.

If the decision in decision block 212 or blocks 209, 210, 214 below is negative, the routine is complete.

FIG. 10 is an interactive / automatic tuning user interface means or routine that begins at block 220 where a user inputs information via the user interface 150. In this embodiment, such information includes, for example, automatic tuning request, request for changing filter notch depth and filter frequency, and / or filter parameter information such as head response request for confirming the response of the engraving head 28. May be included.

In this regard, the user interface screen 150a may have electrical buttons (not shown) for entering or selecting these various requests.

The routine proceeds to decision block 222 where it is determined whether the user has entered a request to change the notch depth or frequency of the notch filter 54. If the request has been entered, the routine proceeds to block 224 where the user interface 15
0 recalculates the filter coefficients for the notch filter 54 and sends it to the tuning processor 52 to complete the routine. As described above, in the example of the user interface screen 150a shown in FIG. 14, such information can be input.

If the decision at decision block 222 is negative, the routine continues to block 226 where it is determined if the user has requested a change in the frequency of the enhancement filter 56. If so, the routine proceeds to block 228 where the user interface 150 recalculates the filter coefficients according to the new frequency entered by the user and sends it to the tuning processor 52 to complete the routine. To do. After recalculating the filter coefficients of the filters 54, 56, the user interface 150 sends the new notch filter coefficient and the emphasis filter coefficient to the notch filter 54 and the emphasis filter 56, and the notch filter 54 and the emphasis filter 56 as described above. Adjust electrically.

If the decision at decision block 226 is negative, then the routine proceeds to decision block 230, where it is determined if the user has entered an autotune request. If so, interface decoder 154 sends a request to feedback controller / means 156 to perform a head response test (block 232). At this time, the tuning processor 52 stops the processing of the actual tool path data sent from the tool path controller 44 via the line 52a, and starts the processing of the test pattern recorded in the memory of the tuning processor 52. To do.

After engraving the test pattern, the feedback controller / means 156 receives the actual position of the cutter needle 30 as detected by the sensor 158 (FIG. 16) in the manner described above. This information is returned to the interface decoder 154 and further sent to the user interface 150 to display the rating (block 23).
4).

If the user interface computer 150 determines that there is an unacceptable deviation between the actual cutter needle 30 response and the requested cutter needle 30 response, the user interface computer 150 will The filter coefficients C ₁ , C ₂ are electrically recalculated and adjusted accordingly (block 236).

Advantageously, the present invention provides a means and method for automatically engraving the engraving head 28 in response to an automatic tuning request entered by the user.

At block 238, the new and / or
Or the adjusted filter coefficient is notch filter 5
4 and the enhancement filter 56, which automatically adjusts the response characteristic 58 as shown in FIG.
After block 238, or if the determination at block 230 is negative, the routine is complete.

FIG. 17 is a schematic view showing all the operating methods. When the power of the device is turned on, the tool path control device 4
4 (block 240), tuning processor 140 (block 242), and interactive / autotune computer 15
0 (block 244) are activated in sequence. At decision block 246, it is determined whether the user has entered a tuning correction request, and if not, the routine returns and repeats from the beginning as shown (decision block 246). If the decision at decision block 246 is Y
If so, the routine proceeds to block 248 and the user interface routine (see FIG. 10) is executed. The routine then repeats in a loop from decision block 246 as shown.

The tuning processor 52 has an internal clock or a timer (not shown) and is set to measure 20,000 times per second. If it is determined at decision block 250 that the timer has expired, the routine proceeds to block 252 where a tuning routine as shown in FIG. 9 is executed. Thereafter, or if the decision at decision block 250 is negative, the routine loops back to decision block 250 as shown.

At decision block 254, it is determined whether a device synchronization signal (not shown) from the engraving controller 38 has been transmitted to the tool path controller 42. If so, the tool path controller synchronization routine described with reference to FIG. 8 is performed. Thereafter, or if the determination at decision block 254 is negative, the routine loops back to block 254.

Although the method and the apparatus for carrying out the method according to the embodiments of the present invention have been described above, the present invention is not limited to the methods and apparatuses according to these embodiments and is described in the claims. Further, the modifications may be made without departing from the spirit of the present invention.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an engraving device of the present invention.

FIG. 2 is a schematic diagram showing a configuration of a processing apparatus of the same embodiment.

FIG. 3 is an explanatory diagram showing an example of image data, reference points obtained by using the image data, and tool paths obtained by using the reference points in the embodiment.

FIG. 4 is an explanatory diagram showing another example of image data, reference points obtained by using the image data, and tool paths obtained by using the reference points.

FIG. 5 is an explanatory diagram showing another example of image data, reference points obtained by using the image data, and tool paths obtained by using the reference points.

FIG. 6 is a flowchart showing a routine for generating a reference point as shown in FIG.

FIG. 7 is a flowchart showing a routine for generating a reference point as shown in FIG.

FIG. 8 is a flowchart of a synchronization routine according to the embodiment of the present invention.

FIG. 9 is a flowchart of the tuning routine and system of the present invention.

FIG. 10 is a flowchart of an autotune user interface routine in one embodiment of the present invention.

FIG. 11 is a graph showing a response characteristic of a conventional engraving head.

FIG. 12 is a graph showing response characteristics of a conventional engraving head after notch filtering.

FIG. 13 is a graph showing the response characteristics of the engraving head subjected to filtering according to the present invention.

FIG. 14 is a diagram showing a user interface according to an embodiment of the present invention.

FIG. 15 is a cross-sectional view showing an engraving head motor, an armature, a speed detection coil, and a pair of electromagnets in an embodiment of the present invention.

FIG. 16 is a block diagram showing a speed and position extraction circuit of a cutting tool according to an embodiment of the present invention.

FIG. 17 is an overall flowchart when the system power is turned on in the embodiment of the present invention.

FIG. 18 is a drawing of a Chinese character engraved using the present invention.

FIG. 19 is a drawing of a Chinese character engraved using a conventional technique.

[Explanation of symbols]

10 engraving equipment 12 sculpture table 24 cylinders 28 engraving head 30 Cutter needle (cutting tool) 38 Engraving control device 40 image processing computer 42 Digital signal processor 44 Tool path control device 46 Reference point generator 48 tool path generator 50 Sync Routine 52 Tuning processor 64 tool path 62a-62i reference point

─────────────────────────────────────────────────── (72) Inventor Neil Clements United States Ohio 45154 Munt Olav Hughes Road 3636 (72) Inventor Louis Jacks Dachesnow United States Ohio 45430 Centerville Laura Avenue 224 (72) Inventor John W. Fraser United States Ohio 45405 Dayton Ridgetail Road 617 (72) Inventor Kenneth W. Jackson United States Ohio 45403 Dayton Ea・ Third Street ・ 3922 (56) References Tokumeihei 9-502936 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41C 1/045 B44B 3/04

Claims (4)

(57) [Claims] 1. A speed detection system for detecting the speed of a cutting tool for engraving a cylinder, comprising: an armature for holding the cutting tool; and at least one of vibrating the armature when energized. At least one electromagnetic drive device having two drive coils; and a sensor provided in association with the at least one electromagnetic drive device for detecting the position of the cutting tool based on the magnetic flux density in the electromagnetic drive device. A speed detection system characterized by being provided. 2. The speed detection system according to claim 1, wherein the sensor is disposed around the at least one electromagnetic drive device and has a magnetic flux density in the electromagnetic drive device.
A constant detecting coil measures the degree, connected to said sensing coil, said sensing a speed of the armature is measured on the basis of the magnetic flux density measured by the coil, the detection circuit for converting the speed to the cutting tool position A speed detection system comprising: 3. The speed detection system according to claim 2 , wherein the detection coil measures a rate of change in magnetic flux through the at least one drive coil. 4. The speed detection system according to claim 2, wherein the detection coil has less than 5 windings around the electromagnetic drive device.