JPH067643Y2 - Print control circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The printing control circuit of the present invention relates to a printing apparatus such as a video printer.

<Prior Art> A video printer is connected to a consumer product such as a television or video and records and stores the image thereof. The printing method of the video printer will be briefly described.

An image from a television or the like is input to a video printer as an NTSC video signal which is a video signal, and this signal
The data is digitized by D / D conversion and is sequentially stored in a field memory, which is a RAM.

The image data input to the field memory is usually 2
It is continuously input as one sub-screen (odd field image, even field image). This data is always rewritten according to the movement of the TV image,
The contents stored in the field memory when this rewriting is stopped are still image data.

Printing of a still image is performed by storing still image data from the field memory in a one-line memory, serially converting the data, and sending the data to a printer to sequentially print the still image line by line. When printing a still image, the printing method is set according to the speed of movement of the television image. The printing method is a frame image and a field image. The frame image is a normal playback method,
In this method, an odd-numbered field image and an even-numbered field image on the field memory are combined and printed as a complete one screen (frame image). However, in this method, when printing an image with a lot of movement, the quality is not good when the image is reproduced as a print due to a temporal image shift between the odd field image and the even field image. In this case, the field image is set, the even field image is discarded, and only the odd field image is printed. In this way, the frame image and the field image are appropriately set according to the image, and a clear still image is printed.

By the way, as a device connected to the video printer, a personal computer or the like can be listed. These video and video signals are usually field pictures. This signal is different from the video video signal which is a frame image, and the phase relationship between the vertical synchronizing signal and the horizontal synchronizing signal of the image is different for the same image. Therefore, the method of reproducing a still image naturally changes depending on whether the device connected to the video printer is a television or the like and a personal computer or the like. Therefore, the video printer dedicated to the above-described device was prepared.

<Problems to be solved by the invention> However, even if there is a request to print a still image regardless of the connected device, when this is carried out, it is connected to the print setting of the video printer. There is a problem that a still image cannot be printed depending on the type of device. This is the case where the setting is a frame image and the video signal is a field image.

The present invention has the above-mentioned problems in a video printer.
It was devised by noting that it does not recognize whether the input video video signal is a field image or a frame image, and the setting is frame image and the video video signal is field image. An object of the present invention is to provide a printing control circuit capable of printing a still image even in some cases.

<Means for Solving Problems> A print control circuit according to the present invention receives a video signal, and determines whether the print data on the field memory is a frame image or a field image based on the signal. When it is determined that it is a frame image, a signal whose logic is inverted in each of the odd field and even field is output. On the other hand, when it is determined that it is a field image, a signal whose logic does not change is output as a field determination signal. The frame discrimination unit and the setting unit that sets whether the printing method of the printer is a frame image or a field image and outputs the setting result as a setting signal are compared with the determination result indicated by the field discrimination signal and the setting result indicated by the setting signal. Then, the state determination unit that outputs as a select signal whether or not the results of both match, and the setting signal outputs the frame image. In the case shown, when the select signal indicates a match, the select signal indicates a signal generated by performing an exclusive OR operation of the toggle signal and the field discrimination signal which are inverted each time the capture signal becomes active. When the signals are shown, the signals whose logic does not change at all times and the active signals showing the writing of the print data to the 1-line memory are output as the print field signals, respectively. On the other hand, when the setting signal shows the field image, the select signal is When it shows a match, it outputs a signal whose logic does not change at all times and outputs an active signal which indicates writing of print data to the 1-line memory, and when the select signal shows a mismatch, it outputs the field discrimination signal as a print field signal. And a printing field signal generating section.

<Operation> When the video signal is a frame image and the printing method setting is a frame image, an exclusive OR operation is performed on the toggle signal and the field discrimination signal that are inverted each time the capture signal is activated. The generated signal is output as a print field signal. As a result, a frame image is printed.

When the video image signal is a frame image and the printing method is set to a field image, the field determination signal is output as a printing field signal. As a result, it is printed as a field image.

When the video signal is a field image, an active signal indicating the writing of the print data in the 1-line memory is output as the print field signal regardless of the setting of the printing method. As a result, in any case, it is printed as a field image.

<Embodiment> FIG. 1 is a circuit configuration diagram of an embodiment of a print control circuit according to the present invention, FIG. 2 is a timing chart showing main signals when a video signal is a frame image, and FIG. 3 is an image. It is a timing chart which shows a main signal when a video signal is a field picture.

The print control circuit of the present invention constitutes a part of the circuit of the video printer. Before explaining the print control circuit, the printer control circuit for controlling the print of the frame image and the field image will be briefly described. I will explain.

The printer control circuit 41 performs predetermined conversion of the video video signal 50 and sequentially writes it to the built-in field memory, while sequentially reading the print data on the field memory line by line in accordance with the setting of the printing system of the printer, and then 1 line. When the writing to the memory is completed and the writing of the printing data for one line to the one-line memory is completed, the capture signal 55 is output each time and the printing data is sequentially read from the one-line memory and output to the printer (not shown). It is structured like this.

The printer control circuit 41 is a circuit that is connected to a thermal head (not shown) and controls to print a still image as either a frame image or a field image. This circuit has a field memory in which the print data of a still image is taken in, and this print data is sent to the thermal head as a thermal head signal 60 via the one-line memory as described in the prior art. . The reading of print data from the field memory to the one-line memory depends on the combination described below.
This is due to the difference in the setting of the printing method on the video printer side and the difference in the method of capturing the printing data due to the difference in the type of connected device. The signal indicating the timing of fetching the 1-line memory is the print field signal 58.
Therefore, the negative logic is output. The print control circuit of the present invention forms this signal, and the printer control circuit
It is a circuit to send to 41.

In addition, a capture signal 55, a select signal 51, and a print start signal 59 are introduced from the printer control circuit 41 to the print control circuit. The capture signal 55 is a signal indicating that the print data has been captured in the one-line memory and is output in positive logic. The select signal 51 will be described later. The print start signal 59 is a negative logic output.

The print control circuit of the present invention is adapted to input the input video signal 50
Field image or field image, and the field / frame discrimination unit 10 which outputs the discrimination result as a field discrimination signal 53, and whether the printing method of the printer is a frame image or a field image is set, and the setting result is set by a setting signal 54. And the setting result output by the field determination signal 53 and the setting result indicated by the setting signal 54 are compared with each other, and a state determination unit that outputs whether or not both results match as a select signal 51 ( Although not shown, this function is realized here by the CPU built in the printer control circuit 41.), the capture signal 55, the select signal 51, the field discrimination signal 53, and the setting signal 54. Print field signal generator 30 for generating and outputting signal 58
It consists of and.

The field / frame discriminating unit 10 discriminates whether the video signal 50 is a frame image or a field image, in other words, discriminates whether the print data on the field memory is a frame image or a field image. This determination method utilizes the fact that the timings of the horizontal synchronizing signal and the vertical synchronizing signal of the video signal 50 are different between the case of a frame image and the case of a field image. When it is determined that it is a frame image, a signal whose logic is inverted in each of the odd field and the even field is output. On the other hand, when it is determined that it is a field image, a signal whose logic does not change (here, an H level signal) is output. The field discrimination signal 53 is output respectively.

The setting unit 20 includes a SW21 and a pull-up resistor 22, and S
When W21 is ON, the setting signal 54 is L level, and SW21
Is connected so that it becomes H level when is OFF.
The former case is field setting, and the latter case is frame setting.

As described above, the state determination section has its function performed by the CPU incorporated in the printer control circuit 41. As shown in FIG. 1, the CPU of the printer control circuit 41 is provided with a field discrimination signal.
53 and the setting signal 54 are input, and the select signal 51 is generated based on these signals. Here, if the determination result indicated by the field determination signal 53 and the setting result indicated by the setting signal 54 match, the L level select signal 51
On the other hand, if they do not match, the H level select signal 51 is output. For example, FIG. 2 shows a case where the field discrimination signal 53 is a frame image (a signal whose logic is inverted in odd field / even field) and the determination signal 54 is also a frame image (H level). In this case, the select signal 51 becomes L level. On the other hand, FIG. 3 shows a case where the field discrimination signal 53 is a field image (H level) and the setting signal 54 is a frame image (H level). In this case, the select signal 51 goes high. The same applies to the other cases.

The print field signal generator 30 is composed of a 4-input / 1-output multiplexer 31, a T-type flip-flop 32 (hereinafter abbreviated as F / F32), and an EXOR33. The fetch signal 55 and the print start signal 59 are introduced to the clock terminal and the clear terminal which are the inputs of the F / F 32, respectively, while the toggle signal 56 is output from the T terminal which is the output thereof. The toggle signal 56 is sent to the second terminal of the multiplexer 31. Also this 1
The No. terminals are grounded, but the field discrimination signal 53 is introduced to the No. 3 and No. 4 terminals. This signal is simultaneously E
It is sent to the input of XOR33. In the multiplexer 31 thus input, the signals for controlling the switching are the setting signal 54 introduced to the A terminal and the select signal 51 introduced to the B terminal, and the switched outputs are , EXOR33 are sent to the other inputs. The print field signal 58 is sent from the output of the EXOR 33 to the printer control circuit 41.

Since the print field signal generation unit 30 has the above-described configuration, the relationship between the setting signal 54, the select signal 51, etc. and the print field signal 58 is as follows.

First, the setting signal 54 is at H level (showing a frame image),
When the select signal 51 is at L level (indicating that the determination result indicated by the field determination signal 53 and the setting result indicated by the setting signal 54 match), the second terminal of the multiplexer 31 is selected. As a result, the signal generated by performing the exclusive OR operation (by EXOR33) of the toggle signal 56 and the field discrimination signal 53 which are inverted each time the capture signal 55 becomes active becomes the printing field signal 58 (first (See Figure 2).

When the setting signal 54 is at the L level (indicating a field image) and the select signal 51 is at the H level (indicating that the discrimination result indicated by the field discrimination signal 53 and the setting result indicated by the setting signal 54 do not match). , The first terminal of the multiplexer 31 is selected. As a result, the signal generated by performing the exclusive OR operation of the L level signal (GND) and the field discrimination signal 53, that is, the field discrimination signal 53 becomes the printing field signal 58.

On the other hand, when the setting signal 54 is at H level (showing a frame image),
When the select signal 51 is at the H level (indicating that the determination result of the field / frame determination unit 10 and the setting result of the setting unit 20 do not match), the fourth terminal of the multiplexer 31 is selected. Similarly, the signal generated by performing the exclusive OR operation (by EXOR33) of the field discrimination signal 53 and the field discrimination signal 53, that is,
The L level signal becomes the print field signal 58.

The setting signal 54 is L level (indicating a field image) and the select signal 51 is L level (field / frame discrimination unit 10).
(Indicating that the determination result of No. 3 and the setting result of the setting unit 20 match), the third terminal of the multiplexer 31 is selected. As a result, the field determination signal 53
And the field discrimination signal 53 are operated by exclusive OR (EX
The signal generated by the OR33), that is, the L level signal becomes the printing field signal 58.

The operation of the print control circuit configured as described above will be briefly described with reference to FIGS. 2 and 3.

FIG. 2 shows a case where the input video video signal 50 is a frame image and the print setting is also a frame image. Therefore, as the print data on the field memory is a frame image, the field discrimination signal 53 has a rectangular wave. The setting signal 54 is at H level. These signals are selection signals for the multiplexer 31, and in this case, the input of the second terminal is output.

First, when printing is started, an active pulse appears in the print start signal 59. When this pulse is output from the printer control circuit 41, the print field signal 58 is printed as the field discrimination signal 53 first falls (at t1).
The initial setting operation is performed such that the power supply falls. That is, this
At t1, the print data of the first line of the odd field image is loaded into the 1-line memory. Then, when the capture signal 55 indicating the completion of the capture is pulse output at the time of T2, the toggle signal 56 rises, and at the same time, the print data is read from the one-line memory and the first line of the still image is printed. . Further, the rising edge of the toggle signal 56 is latched until the capture signal 55 becomes new active. On the other hand, the print field signal 58 is a signal which is the exclusive OR of the signal 57 and the field discrimination signal 53, and the signal 57 is the toggle signal 56 connected to the second terminal as described above. This print field signal 58 is
Until the next time T6, the waveform will be as shown in Fig. 2, and T3 and
Although it is active during T4, the contents of the 1-line memory are not rewritten during printing (at T2 to T5). When the printing of one line is completed at T5, the printing field signal 58 becomes active at the same time when the field discrimination signal 53 rises (at T6). At this time, since the field discrimination signal 53 indicates an even field image, the print data of the first line of the even field image is fetched in the 1 line memory. After that, at T7, when a pulse appears in the capture signal 55, printing is started, and at the same time, the toggle signal 56 falls. A still image is printed through the operations described above, but this printing is performed as a frame image as set.

The input is the same, and the operation when the setting is a field image will be described. In this case, the setting signal 54 is L
The input of the multiplexer 31 is most selected as the level becomes high. That is, the signal 57 is always at the L level, and the print field signal 58 is the same signal as the field discrimination signal 58. This is because the printing data of odd field image is 1
It is shown that the line memory is sequentially loaded and printed.

FIG. 3 shows a case where the input video video signal 50 is a field image and the print setting is a frame image. In this case, the setting signal 54 becomes the H level, so that the multiplexer 31 selects the field discrimination signal 52. Therefore, the print field signal 58 is at the L level which is always active. Therefore, when the capture signal 55 indicates that the print data is captured in the 1-line memory,
The printing of the line is started, and at the same time as the printing is finished, the printing data of the second line is taken into the 1-line memory and printed in the same manner. It has been explained here that the print field signal 58 is a signal for printing with a field image when the video video signal 50 is a field image and the print setting is a frame image, which is the object of the present invention.

The input will be described with respect to the case where the same print setting is used as a field image. In this case, the multiplexer 31 operates in exactly the same manner as the field discrimination signal 53 is selected as in the case described above. In other words, it will be printed as a field image.

As described above, the print field signal 58 output by the print control circuit of the present invention is a signal for controlling the print regardless of the type of the video video signal 50 and the setting thereof. It was explained.

The components of the print control circuit of the present invention are not limited to those in the above-described embodiment, and the field / frame discrimination unit has a hardware configuration, and the print field / frame discrimination unit has the same operation. It can also be implemented by substituting it with a circuit.

Effects of the Invention As described above, the print control circuit according to the present invention can print even if the setting of the printing method of the printer does not match the video video signal due to the configuration. That is, regardless of the type of device connected to the video printer, printing can be performed regardless of the setting of the printing method. There is also an advantage in improving the usability of the video printer.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of an embodiment of a print control circuit according to the present invention, FIG. 2 is a timing chart showing main signals when a video video signal is a frame image, and FIG. 3 is a video video signal in a field. It is a timing chart which shows the main signals when it is a picture. 10 …… Field / frame discrimination section, 20 …… Setting section, 30
...... Print field signal generator, 41 ...... Printer control circuit, 50 …… Video video signal, 53 …… Field discrimination signal, 55 …… Capture signal, 58 …… Print field signal.

Claims (1)

[Scope of utility model registration request] 1. A video / video signal is converted into a predetermined signal and sequentially written in a field memory, while print data in the field memory is sequentially read line by line in accordance with a print mode setting of a printer, and then written in a 1 line memory. 1
A circuit equipped in the printer control circuit that outputs a capture signal each time the print data for one line is written to the line memory and sequentially reads the print data from the one line memory and outputs the print data to the printer. Then, in the print control circuit that generates the print field signal that gives the timing of writing the print data from the field memory to the one-line memory, the video video signal is input, and the print data on the field memory is changed based on the signal. When it is determined that the image is a frame image or a field image, and when it is determined that it is a frame image, a signal in which the logic is inverted in each of the odd field and the even field, on the other hand, when it is determined that it is a field image, the logic does not change. Field / frame format that outputs each signal as a field discrimination signal Section, a setting section that sets whether the printing method of the printer is a frame image or a field image and outputs the setting result as a setting signal, and compares the determination result indicated by the field determination signal with the setting result indicated by the setting signal. When the setting signal indicates a frame image and the state determination unit that outputs whether or not the results of both match as a select signal, when the select signal indicates a match, the capture signal is inverted every time it becomes active. When the select signal indicates disagreement, the signal generated by performing the exclusive OR operation of the toggle signal and the field discrimination signal is a signal whose logic does not always change, and the print data is written in the 1-line memory. While the active signal shown in the figure is output as the print field signal, the select signal is Indicates that the logic does not change at all, and an active signal indicating that the print data is written to the 1-line memory is output. When the select signals indicate a mismatch, the field determination signal is output as the print field signal. A print control circuit comprising a print field signal generator.