JP3036889B2 - Analog input processing circuit adjustment method for video printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting an analog input processing circuit of a video printer having a monitor output function of a video signal stored in a memory for holding printing information.

[0002]

2. Description of the Related Art Conventionally, a video printer having a monitor output function is disclosed, for example, in Japanese Patent Application Laid-Open No. 63-42290 (H0).
4N 5/91), the input video signal (analog video signal) of the analog input terminal is
After processing and processing such as C separation and color signal decoding, the data is digitized and written into a memory for holding printing information, and the signals in this memory are read to generate a printing image and a monitor video signal. Further, this type of video printer is provided with a digital input terminal together with an analog input terminal. Some digital printers perform printing of a digital video signal such as a computer image supplied to the digital input terminal and generation of a monitor video signal. .

Next, a video printer having a monitor output function having an analog input terminal and a digital input terminal will be described with reference to FIGS. 1 and 2 showing a first embodiment of the present invention. As shown in FIG. 1, the analog input terminal 1
Of the analog video signal of the analog input processing circuit 2
The input video signal is separated into a luminance signal and a carrier chrominance signal by the separation circuit 3. The luminance signal is supplied to an A / D conversion circuit 4, and the carrier chrominance signal is supplied to a decoder 5. .

The decoder 5 is configured as shown in FIG. 2, and the carrier chrominance signal is supplied to a voltage control amplifier circuit 6 and a burst gate pulse generation circuit 7. And the generating circuit 7
The burst gate circuit 8 of the APC control loop extracts the burst signal of the carrier chrominance signal based on the burst gate pulse, and the gain of the amplifier circuit 6 is automatically controlled by the ACC detection circuit 9 based on this signal. The color saturation is automatically adjusted based on the voltage.

A burst signal from the burst gate circuit 8 is supplied to an APC detection circuit 12 via a hue adjustment circuit 11, and based on a phase detection output from the detection circuit 12, V
An oscillation circuit 13 having a CO configuration generates a color reference subcarrier signal for reproduction, and this signal is transmitted via a phase shifter 14 to RY and BY signals.
Are supplied to the demodulation circuits 15 and 16. Then, the carrier chrominance signal passed through the amplification circuit 6 is converted by the demodulation circuits 15 and 16 into R-color signals.
Are demodulated into Y, BY color difference signals, and the two color difference signals are A
/ D conversion circuit 4.

The external variable resistor 1 of the adjusting circuit 11
The resonance circuit constant of the adjustment circuit 11 is controlled by the adjustment voltage 7 to adjust the phase of the burst signal, thereby adjusting the hue of the reproduced image based on the two color difference signals. The analog video signal is converted into a digital converted video signal composed of luminance data and two kinds of color difference data by digital conversion of the A / D conversion circuit 4, and this video signal is stored in a memory 6 for holding printing information. It is supplied as an input signal.

On the other hand, a digital video signal such as a computer image is supplied from a digital input terminal 17 to a microcomputer 1 for controlling the interface circuit 18 and the whole.
9 to the memory 6. By the way, this type of video printer is generally used for generating a print of an analog video signal such as a television broadcast screen and a reproduced video screen.
An analog input terminal 1 is always connected to a reproduction output terminal of a television receiver, a video tape recorder, or the like.

Therefore, the converted video signal is supplied to the memory 6 even when the printing of the analog video signal is unnecessary. On the other hand, the digital input terminal 17 is connected to a computer device or the like only when printing of a digital video signal is necessary, and is used.
The digital video signal is supplied to the memory 6 only at the time of printing. Then, under the control of the memory of the computer 19, the converted video signal and the digital video signal are taken in while selectively rewriting the memory 6 with priority given to the digital video signal.

Further, the video signal fetched into the memory 6 is read out as a holding signal to the D / A conversion circuit 20 on the monitor output side, and is converted into an analog signal. The luminance signal and the two color difference signals formed by this analog conversion are converted into analog signals. It is supplied to the YC superimposing circuit 22 and the encoder 23 of the monitor output processing circuit 21.

A carrier chrominance signal is reconstructed by an encoder 23, and this signal is supplied to a superimposition circuit 22 via a saturation adjustment circuit 24. The superimposition circuit 22 superimposes the carrier chrominance signal on the luminance signal and synthesizes it. Then, an analog monitor video signal similar to the input video signal is generated, and this signal is supplied from the output terminal 25 to a monitor television or the like and displayed on the monitor.

A signal for holding the desired screen in the memory is supplied to the computer 19, the drive circuit 26, and the printing processing circuit of the printing head 27 as printing data based on the printing command. The color print of the desired screen is printed out by the sublimation type thermal transfer. By the way, the analog input processing circuit 2 usually needs to set circuit characteristics so that a change (deterioration) of signal characteristics due to the circuit 2 does not occur.

When a video printer of this type is manufactured, for example, gain adjustment and hue adjustment of the decoder 5 by the variable resistors 16 and 17 in FIG. 2 are performed as circuit adjustments (analog input processing circuit adjustments) of the processing circuit 2. Done. Conventionally, these adjustments are performed using an oscilloscope by adjusting a variable resistor or the like so that the signal waveform to be measured has a specified level or a specified shape.

That is, in the case of the gain adjustment and the hue adjustment for the color signal, the waveforms of the color difference signals of the demodulation circuits 15 and 16 in FIG. 2 are measured by an oscilloscope, and the color difference signal of the demodulation circuit 15 becomes a specified level. Variable resistor 10
Is operated to adjust the gain, and the gain is adjusted by operating the variable resistor 17 so that the gradient of the waveform of the color difference signal of the demodulation circuit 16 becomes a specified state.

[0014]

In the conventional analog input processing circuit adjusting method, the operation is complicated because the waveform to be measured is set to a prescribed level and shape to adjust the characteristics, and the adjustment can be easily performed. In addition, there is a problem that the adjustment error becomes large. Further, since only the specified characteristics are set by adjustment, variations in the printing characteristics of the printing head 27 and the recording paper are not compensated, and a desired printed image cannot be obtained based on these variations. There is also.

The present invention is applied to a video printer which generates a printed image of an analog video signal and a digital video signal by giving priority to a digital video signal, and is an analog input processing circuit of a video printer which is very simple and suitable for automation. It is intended to provide an adjustment method. An analog input processing circuit adjustment method for a video printer which is applied to at least a video printer which generates a print of an analog video signal and which can compensate for variations in printing characteristics with extremely simple adjustment suitable for automation. The purpose is to provide.

[0016]

In order to achieve the above object, in a method for adjusting an analog input processing circuit of a video printer according to the present invention, in the case of claim 1, an analog video signal and a digital video signal of the same video source are converted . It is supplied to both input terminals simultaneously, and the digital video signal
It takes the issue to the memory, analog video of analog input terminal
Memory signal processed by the analog input processing circuit.
Read the signal waveform of the video signal on the log input side and memory
Of the converted digital video signal into analog
Comparing the signal waveforms of the monitor output of the video signal, notes
The signal waveform of the video signal on the analog input side of the memory
Of the video signal on the monitor output side
Next, the characteristics of the analog input processing circuit are adjusted.

Further, according to the case of claim 2, eye indicia copy information holds the A Narogubideo signal through the analog input processing circuit
Memory, read the holding signal of this memory and generate
Which was converted into a video signal read by an image scanner Shirushiutsushiga, analog input side of Shinano return the read video signal of the scanner to the analog input terminal to stop the signal acquisition of memory is lame Mori and monitor Compare the signal waveform on the output side ,
To adjust the characteristics of the analog input processing circuit to match the analog input side of the signal waveform ducks Nita output side of the signal waveform.

[0018]

According to the adjusting method of the present invention, the digital video signal is preferentially taken into the memory for holding the printing information. Based on the simultaneous supply of the analog video signal and the digital video signal, the analog input side of the memory
Signal waveform of the video signal becomes the waveform affected by the characteristics of the analog input processing circuit, the <br/> signal waveform of the monitor output side of the video signal Do affected characteristic of the analog input processing circuit
Have a waveform of the same video source.

The analog input processing is performed so that the signal waveform on the analog input side matches the signal waveform on the monitor output side.
To adjust the characteristics of the physical circuit, rather than conventional such annoyance sloppy operation, characteristics of the analog input processing circuit by a very simple operation suitable for automated match 2 signal waveforms digital
It is adjusted to be the same as the case of the input .

Further, in the case of the configuration of claim 2, a video signal (read video signal) of a printed image is formed by reading by the image scanner , and reading is performed in a state where the signal capturing of the memory for holding the printed information is stopped. A video signal is provided to the analog input of the memory.

At this time, reading of the analog input side of the memory
The signal waveform of the video signal is a waveform affected by variations in the printing characteristics of the printing head, recording paper, etc., and the signal waveform of the holding signal on the monitor output side of the memory is an analog input signal not affected by the variations. Original video through processing circuit
It becomes a signal waveform. Then, so that the signal waveform on the analog input side of the memory matches the signal waveform on the monitor output side ,
To adjust the characteristics of the analog input processing circuit, by a very simple operation suitable for automated match 2 signal waveform, equivalently, adjusted on the properties characteristic of the analog input processing circuits to compensate for variation in indicia shooting characteristics And roses in printing characteristics
Regardless of the type, a printed image having the characteristics of the input video signal can be obtained .

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to FIGS. (First Embodiment) First, a first embodiment will be described with reference to FIGS. In this example,
An analog video signal and a digital video signal of the same video source are supplied, and manual adjustment is performed by comparing analog signal waveforms using an oscilloscope.

Therefore, an analog video signal and a digital video signal of an appropriate screen such as a test pattern of the same video source are simultaneously supplied to input terminals 1 and 17 from an input signal generating device described later, and the digital video signal is controlled by the computer 19. Is taken into the memory 6 preferentially. At this time,
The analog video signal is digitally converted by the A / D conversion circuit 4 via the analog input processing circuit 2, and the converted video signal formed by this conversion is supplied to the analog input side of the memory 6.

The digital video signal taken into the memory 6 is read out as a holding signal to the monitor output side,
After being analog-converted by the A-conversion circuit 20, it is processed into a monitor video signal by the monitor output processing circuit 21 and output from the output terminal 25. In order to adjust the gain and hue of the decoder 5 provided in the processing circuit 2, an oscilloscope probe is connected to A and B in FIG. 1 and the decoder 5 of the processing circuit 2 passes through the A / D conversion circuit 4. Memory 6
And a waveform of the color difference signal on the monitor output side supplied from the memory 6 to the encoder 23 of the processing circuit 21 via the D / A conversion circuit 20 is compared.

At this time, the color difference signal on the analog input side is affected by the gain and hue characteristics of the decoder 5, but the color difference signal on the monitor output side is not affected by the gain and hue characteristics. Further, the variable resistors 10 and 17 of the decoder 5 are adjusted while comparing the two waveforms of the oscilloscope, and the gain and hue of the decoder 5 are adjusted by matching the waveform of the color difference signal on the analog input side with the waveform of the color difference signal on the monitor output side. I do.

FIG. 1 shows an oscilloscope probe.
1A and 1B, the color signal system of the processing circuit 2 can be adjusted based on the comparison of the color difference signal waveforms. By connecting the oscilloscope probe to C and D in FIG. Based on the comparison, adjustment of the luminance signal system such as contrast adjustment of the processing circuit 2 can be performed. Therefore, the processing circuit 2 can be adjusted with high accuracy by a simple operation of matching the two signal waveforms while looking at the oscilloscope.

An analog video signal and a digital video signal of the same video source are formed, for example, by the input signal generator 28 shown in FIG. That is, the creating device 28 converts the analog source video signal such as the test pattern into an AG signal.
The AGC circuit 29 supplies the source video signal to the input terminal 1 as an analog video signal.

The analog video signal of the AGC circuit 29 is converted into a luminance signal and RY and BY color difference signals by a YC separation circuit 30 and a chrominance signal decoder 31, and these signals are converted to an A / D conversion circuit. The digital video signal is converted into a digital video signal by the digital circuit 32, and the digital video signal is supplied to the input terminal 17 via the interface circuit 33.

Second Embodiment Next, a second embodiment will be described with reference to FIG. FIG. 4 shows a case in which an analog video signal and a digital video signal of the same video source are supplied, and automatic adjustment is performed by comparing digital signal waveforms. In FIG. 4, the same reference numerals as those in FIGS.

As in the case of the first embodiment, FIG.
An analog video signal and a digital video signal of the same video source are supplied to the input terminals 1 and 17 from the input signal generator 28 and the like, and the digital video signal is taken into the memory 6. Further, the adjustment mode is instructed to the computer 19 by button operation or the like, and the comparison circuit 34 is activated. When the gain and hue of the decoder 5 are adjusted, the comparison circuit 34 sets A
The data of the color difference signal on the analog input side supplied from the / D conversion circuit 4 to the memory 6 and the D / A conversion circuit 2 from the memory 6
The data of the color difference signal on the monitor output side of the memory 6 read to 0 is repeatedly compared separately for RY and BY.

Further, the comparison result of the comparison circuit 34 is supplied to the voltage generation circuit 35 of the computer 19, and the RY and BY adjustment control voltages of the voltage generation circuit 35 are adjusted in the comparison cycle until the comparison results match. It changes stepwise.
Further, the setting voltage of the gain and the hue of the adjusting circuit 34 according to the two adjusting control voltages of the voltage generating circuit 35 is supplied to the decoder 5, and at this time, the decoder 5 is connected to the variable resistors 10 and 1 in FIG.
7 is omitted, and both set voltages are amplified by the amplifier circuit 6 and the hue adjustment circuit 1
1 is applied.

When the signal waveform on the analog input side matches the signal waveform on the monitor output side, the computer 19 ends the adjustment mode based on the comparison result of the comparison circuit 34, stops the comparison circuit 34, and The data of the two adjustment control voltages are preset and held in the memory 37. Thereafter, until the adjustment mode is set again and the contents of the memory 37 are reset and cleared, both set voltages based on the data held in the memory 37 are generated and applied to the circuits 6 and 11.

Accordingly, the gain and hue setting voltages of the decoder 5 are variably adjusted and set by automatic control of the computer 19. In the case of contrast adjustment, the brightness output level of the YC separation circuit 3 is automatically adjusted by comparing the brightness signal data on the analog input side and the monitor output side of the memory 6 by the comparison circuit 34. And the comparison circuit 3
Based on the comparison result of 4, the necessary characteristics of the processing circuit 2 can be automatically adjusted.

Third Embodiment Next, a third embodiment will be described with reference to FIG. In this embodiment, the characteristics of a printed image are adjusted by manual adjustment of analog signal comparison using an oscilloscope based on a video signal read by a scanner.

In FIG. 5, the same reference numerals as those in FIGS. 1 to 4 denote the same or corresponding elements. First, for example, the characteristics of the analog input processing circuit 2 are adjusted by the adjusting method of the first and second embodiments. Make initial adjustments.

Next, in order to detect variations in printing characteristics of the printing head 27, recording paper, etc., an appropriate screen such as a test pattern is printed out by the printing head 27, and the actual image obtained by this printing is obtained. Is read by an image scanner 39 to form a video signal (read video signal) of the printed image 38. At this time, for example, assuming that the color signal amplitude of the original video source supplied to the analog input terminal 1 is 1, the color signal amplitude is also set to 1 in the processing circuit 2 and the memory 6 by the above initial adjustment. Become.

Further, the variation in the characteristics of the driver 26 and the printing head 27 is represented by a, and the variation in the characteristics of the recording paper is represented by b.
If (a, b≪1), the color signal amplitude of the print 38 is (1 + a) (1 + b) ≒ 1 + a + b. Then, the read video signal of the scanner 39 is supplied to the calibration circuit 40,
The circuit 40 calibrates a characteristic error based on the conversion efficiency of the scanner 39 and supplies a read video signal of the characteristic (= 1 + a + b) of the print 38 to the input terminal 1.

Further, the computer 19 stops taking in signals from the memory 6. At this time, the color signal amplitude on the analog input side of the memory 6 becomes 1 + a + b, and the color signal amplitude on the monitor output side of the memory 6 becomes 1. If the gain of the decoder 5 is to be adjusted, the oscilloscope probe is connected to A and B in FIG. 5 and the waveform of the RY color difference signal on the analog input side supplied to the A / D conversion circuit 4 and D / D The waveforms of the RY color difference signals on the monitor output side output from the A conversion circuit 20 are compared.

Further, the variable resistor 10 of the decoder 5 is adjusted, and the gain of the decoder 5 is adjusted so that the RY color difference signal waveform on the analog input side matches the RY color difference signal waveform on the monitor output side. . At this time, the color signal amplitude characteristic of the processing circuit 2 becomes 1-ab, and after the adjustment, the video signal is supplied to the input terminal 1 to generate a printed image. 1-ab, and this 1-a
The signal of −b is (1-ab) · (1 + a) ≒ 1−b in the driver output based on the variations a and b, and is (1−b) (1 + b) ≒ 1 in the print 38. .

Therefore, the color signal amplitude characteristic of the processing circuit 2 is adjusted to a characteristic in which the variation of the printing characteristic is accurately compensated by a simple operation for matching the two signal waveforms. Regardless of the variation, a printed image 38 having the same color signal amplitude characteristics as the video signal supplied to the input terminal 1 is obtained.

When adjusting the hue of the decoder 5, the oscilloscope probe is connected to A and B in FIG.
The waveform of the color difference signal on the analog input side supplied to the D conversion circuit 4 and the waveform of the color difference signal on the monitor output side output from the D / A conversion circuit 20 are compared with each other. May be adjusted. For contrast adjustment, connect the oscilloscope probe to C in FIG.
D and the luminance output level of the YC separation circuit 3 may be adjusted in the same manner as described above.

(Fourth Embodiment) Next, a fourth embodiment will be described with reference to FIG. FIG. 6 shows a case where automatic adjustment is performed by digital signal comparison based on a video signal read by a scanner. In FIG. 6, the same reference numerals as those in FIGS. 1 to 5 denote the same or corresponding components. Then, as in the case of the third embodiment, first, the characteristics of the analog input processing circuit 2 are initially adjusted by, for example, the adjustment methods of the first and second embodiments.

Next, in order to detect variations in the printing characteristics of the printing head 27 and recording paper, an appropriate screen such as a test pattern is printed out by the printing head 27, and the actual screen obtained by this printing is obtained. Is read by a scanner 39, and a read video signal of the scanner 39 is supplied to the input terminal 1 via a calibration circuit 40. At this time, the adjustment mode is instructed to the computer 19, the writing to the memory 6 is stopped, and the comparison circuit 34 operates.

The operation of the voltage generating circuit 35 and the adjusting circuit 36 based on the comparison result of the comparing circuit 34 automatically adjusts, for example, the color signal amplitude characteristic of the processing circuit 2 in the same manner as in the second embodiment. Further, after the adjustment is completed, the processing circuit 2
Is set.

Therefore, the characteristics of the processing circuit 2 are automatically adjusted to the characteristics in which the variation in the printing characteristics is compensated by the automatic control of the computer 29 as in the case of the second embodiment. The hue adjustment and the contrast adjustment of the processing circuit 2 can be automatically performed in the same manner as described above.

[0046]

Since the present invention is configured as described above, the following effects can be obtained. First, in the case of the configuration according to claim 1, digital video signals of the analog video signal and the same video source is taken to preferentially memory 6, the signal waveform of the analog input side of the video signal in the memory 6 is analog becomes the wave <br/> type affected by the characteristics of the input processing circuit 2, the signal waveform of the monitor output side of the video signal in the memory 6 not subject to influence of the characteristic of the analog input processing circuit 2
Becomes the waveform of the same video source, the signal waveform of the analog input side in this state to adjust the characteristics of the input processing circuit 2 so as to match the output waveform of the monitor output side, as in the prior art
Annoyance not sloppy operation, by a very simple and little error operation suitable for automated match 2 signal waveform, the analog
The characteristics of the input processing circuit 2, the analog and digital inputs
Can be adjusted so that there is no difference between .

In the case of the configuration of claim 2, the input processing
The input video signal via the circuit 2 is fetched into the memory 6 and
38 generated by reading the holding signal of the memory 6 of FIG.
Is read by the image scanner 39 to form a read video signal of the print 38, and the read video signal is sent to the analog input side of the memory 6 in a state where the signal reading of the memory 6 is stopped.
Since the back, the video signals read analog input side of the memory 6
The signal waveform of the signal is affected by the variation in the printing characteristics of the printing head 27, recording paper, etc., and the signal waveform of the signal held in the memory 6 on the monitor output side of the memory 6 is affected by the variation. Original video via input processing circuit 2
It becomes the signal waveform of the E signal . Then, the signal waveform of the analog input side of the memory 6 is adjusted to match the signal waveform of the monitor output side, by a very simple operation which was also applied to an automated match 2 signal waveform of the input processing circuit 2 Characteristics Is adjusted to a characteristic that compensates for the variation in the printing characteristics
And prints the characteristics of the input video signal regardless of the printing characteristics.
The resulting can Rukoto.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of a method for adjusting an analog input processing circuit of a video printer according to the present invention.

FIG. 2 is a detailed block diagram of the decoder of FIG.

FIG. 3 is a block diagram of an input signal generation device used for adjustment in FIG. 1;

FIG. 4 is a block diagram of a second embodiment of the present invention.

FIG. 5 is a block diagram of a third embodiment of the present invention.

FIG. 6 is a block diagram of a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Analog input terminal 2 Analog input processing circuit 6 Memory for holding printing information 17 Digital input terminal 21 Monitor output processing circuit 27 Printing head 36 Printing image 37 Image scanner

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 9/79-9/898 H04N 5/91-5/956

Claims (2)

(57) [Claims] 1. An analog input processing circuit for YC separation,
A converted video signal is formed by digitally converting an analog video signal of an analog input terminal subjected to color signal decoding and the like, and the converted video signal and the digital video signal of the digital input terminal are printed by giving priority to the digital signal. The information is stored in a memory for storing information, a read signal stored in the memory is read and supplied to a printing processing circuit and a monitor output processing circuit, and a printing image is generated by a printing head of the printing processing circuit. in monitoring the input processing circuit adjustment method for a video printer to produce a monitor video signal by processing the hold signal by the circuit, and supplies at the same time a Narogubideo signal of the same video source, the digital video signal to the two input terminals, the digital Record the digital video signal of the input terminal
Analog capture, analog video signals of the analog input terminal Li
The analog input side of the memory processed by the input processing circuit
The signal waveform of the video signal and the data read from the memory
Monitor of the memory which converted the digital video signal into analog
The signal waveform of the video signal on the analog input side of the memory is compared with the signal waveform of the video signal on the data output side.
Is the signal waveform of the video signal on the monitor output side of the memory.
A method for adjusting an analog input processing circuit of a video printer , wherein the characteristic of the analog input processing circuit is adjusted so as to conform to the following . 2. An analog video signal from an analog input terminal is processed by an analog input processing circuit and taken into a memory for holding printing information, and a signal held in the memory is read and supplied to a printing processing circuit and a monitor output processing circuit. An analog input processing circuit adjustment method for a video printer, wherein a print image is generated by a print head of the print processing circuit, and the monitor signal is processed by the monitor output processing circuit to generate a monitor video signal. An analog video signal is supplied to the analog input processing circuit.
Through the memory, read the holding signal of the memory, read the printed image by an image scanner and convert it to a video signal, stop the memory signal capture, and read the video signal read by the scanner. comparing the signal waveform of the analog input side and the monitor output side of the memory while back to the analog input terminal, the signal waveform of the analog input side the read video signal the holding signal signal waveform of the monitor output of the A method for adjusting an analog input processing circuit of a video printer, comprising adjusting characteristics of the analog input processing circuit so as to match.