JPS606519B2 - Imaging method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an imaging method applied to control the line thickness and brightness of characters displayed on the display surface of a CRT.

In a device that selects a desired character from among a large number of characters provided on a dial face, photographs it with an image pickup tube, and reproduces a character image on the display surface of a CRT according to the obtained video signal, the reproduced character Variations in visual brightness occur depending on the typeface, number of strokes, series (size), etc. of the image.

In general, typefaces with thicker strokes, characters with more strokes, and characters with smaller series appear to have higher brightness. Also, CR is like a phototypesetting machine.
Even when the character image reproduced on the T is projected and printed onto a photosensitive material, the printed matter has similar visual density variations. The purpose of this invention is to determine the pulse width of a video signal.
The object of the present invention is to provide an imaging method that can freely control the wave height, control the line thickness and brightness, and eliminate visual variations in brightness. In this invention, the pulse width of the video signal,
In order to control the wave height, a method is adopted that changes the target potential of the image pickup tube, and more specifically, it uses the fact that the amount of charge flowing from the target bias power supply during initial scanning determines the size of the video signal. The pulse width and wave height of the video signal are controlled by changing the target bias voltage of the image pickup tube during character projection and display scanning.

For example, if the target bias voltage at the time of starting scanning is lower than the target bias voltage during projection, the amount of charged charge will decrease accordingly, and the video signal obtained at that time will not change the target bias voltage throughout the time of projection starting scanning. compared to the video signal obtained when Conversely, if the target bias voltage is increased, the resulting video signal will become larger. Therefore, by setting the target bias voltage to a constant reference value throughout each character during projection, and changing the target bias voltage as necessary for each character during projection scanning, you can obtain a video signal of the required size. be able to. Next, an embodiment of the present invention will be described based on FIG.

In the following description, a phototypesetting machine to which the method of the present invention is applied will be described as an example. The figure shows the configuration of the main parts of a phototypesetting machine to which the method of the present invention is applied. In this phototypesetting machine, a character generating section has a disc-shaped dial 1 and a light source (for example, a flash lamp) 2. On the dial 1, a large number of letters Q and symbols are arranged in the same D circle shape at predetermined intervals. The shape of the dial 1 may be a belt, a drum, a strip, or the like. The dial 1 is rotated by a drive source (not shown), and when the selected desired characters are clustered at a predetermined position, the light source 2 emits light to generate a character light of the desired character. For this purpose, the dial 1 is provided with a detection mechanism 3 consisting of a light source and a photoelectric conversion element for detecting its rotational position and calculating a desired character position.
This detection mechanism 3 may have a configuration in which a rotary encoder or the like is provided coaxially with the rotation axis of the dial 1. The character light generated from this character generating section is projected onto the image pickup tube 5 via the imaging lens 4.

The image pickup tube 5 generates a video signal by scanning the characters projected on the target surface, and this video signal is sent to a video amplifier 6, a waveform shaping circuit 7, and a video amplifier 8.
is supplied to the CRT 9 via the CRT 9, and a desired character image is reproduced on its display surface. This reproduced character image is projected onto the photosensitive material 11 via the lens IQ, and predetermined printing is performed. 12 is CP
U receives external commands given to the phototypesetting machine and generates various control commands.

Further, in this case, the dial 1 is also a storage unit that stores voltage value information of a target bias voltage during readout scanning of the image pickup tube 5 corresponding to each character stored therein. Reference numeral 13 denotes a control circuit which controls the entire apparatus according to control commands from the CPU 2.

Reference numeral 14 denotes an ignition control circuit that controls the light source 2 according to commands from the control circuit 13.
control the ignition of the

15 is a drive circuit for the image pickup tube 5, and 16 is a drive circuit for the CRT 9.

A register 17 stores target bias voltage value information corresponding to a desired character read out from the CPU 2 and transferred in response to an external EO character command.

The D/A converter 8' converts the contents of the register 17 into an analog value and outputs it to the target bias voltage control amplifier 19. Next, the EO motion will be explained.

First, a print character command for a desired character is input to the CPU turtle 2 from the outside. At this time, it is assumed that the afterimage on the target surface of the rice bran image tube 5 is erased, and the target bias voltage is maintained at an appropriate reference value. And control circuit turtle 3 is CPU1
The detection mechanism 3 detects a desired character position on the dial 1 according to the print character command transferred from the image pickup tube 2, and when the desired character reaches the imaging position, the light source 2 is ignited via the ignition control circuit 14. A desired character is projected onto the target surface of the image pickup tube 5 and the target bias voltage is changed from the reference value to a predetermined voltage value when scanning is performed. The voltage value information of the target bias voltage during the spelling scan corresponding to the desired character is outputted from the register 17, and the target bias voltage is determined by the voltage value information via the D/A converter 18 and the target bias voltage control amplifier 9. Note that the output and transfer timing of the voltage value information can be determined freely, and in short, if the target bias voltage can be set to a predetermined value after photographing the desired character on the image pickup tube 5 and before starting scanning. Further, the voltage value information output to the register 7 is canceled immediately after the reading scan of the desired character projected on the image pickup tube is completed, and the target bias voltage is maintained at the reference value. These are controlled by the control circuit 3, but the specific circuit can be configured freely.When the target bias voltage is controlled to a predetermined value, the image pickup tube 5 is driven to start readout scanning. The video signal is controlled to an appropriate pulse width and wave height by the target bias voltage at that time, and is supplied to the CRT 9 via the subsequent video amplifier 6, waveform shaping circuit 7, and video amplifier 8, and the desired character image is displayed on its display screen. It is reproduced and printed on Kanmura 11.The printed matter thus obtained is of high quality, with variations in visual density caused by the number of strokes, series, etc. of the typeface removed.Next, for the same purpose as mentioned above, As a method for changing the target potential of the image pickup tube, a method of exposing the entire target of the image pickup tube to light immediately before character projection will be described.

This method utilizes the characteristic that the closer the target potential is to the cathode potential during character projection, the smaller the resulting video signal, and vice versa, the larger the video signal. Immediately before character projection, the entire target surface is exposed to light and the target potential is controlled so that a video signal with a desired pulse width and wave height can be obtained. Regarding the embodiment adopting this second method, the second
This will be explained based on the diagram.

Incidentally, FIG. 2 shows a case where the apparatus is applied to a phototypesetting machine as in FIG. 1, and since the same members are given the same numbers, the explanation thereof will be omitted. In this embodiment, a light emitting diode 20 is used as a light source that provides a predetermined exposure over the entire surface of the target. Of course, the light source is not limited to a light emitting diode. Furthermore, in the following explanation, it is assumed that the amount of exposure on the target surface is controlled by changing the light emission intensity of the light emitting diode 20, but the purpose can also be achieved by changing the lighting time of the light emitting diode 20. In this embodiment, the CPU 12 stores information on the amount of exposure to be applied to the entire surface of the target corresponding to each character. 21 is a resistor, 22 is a D/A converter, 23 is an amplifier, and 24 is a current control circuit. Next, the operation will be explained.

First, a print character command for a desired character is input to the CPU 12 from the outside. At this time, the afterimage on the target surface of the image pickup tube 5 is erased and the target potential is maintained at a standard value. Then, the exposure amount information of the target surface corresponding to the desired character is immediately read out from the CPU 12, and the D/A A current control circuit 24 is set in the converter 22 via an amplifier 23. Next, upon receiving a lighting signal from the control circuit 13, the light emitting diode 2 emits light at a predetermined intensity, exposing the entire surface of the target of the image pickup tube 5 to a predetermined amount. In this way, the target potential is controlled to a value corresponding to the desired character to be projected.After this, the desired character is projected onto the green image tube 5, readout is scanned, and the CRT
9 and printing on the printing area 11 is performed. In this way, similar to the above-mentioned method, this second method also provides a high quality printed matter on the printing plate 11 with no visual density variations. Furthermore, as another method for controlling the target potential, for example, the grid potential may be controlled when erasing the afterimage of the image pickup tube 5.

− method is effective. In this case as well, CP
Needless to say, it is sufficient to store the amount of grid potential fluctuation corresponding to each character in U12. that's all,
As has been described variously, in each system, the factors that determine the information to be stored in the CPU 12 are basically the font of each character, the number of strokes, the size (series) of the character to be printed at that time, etc.

The typeface is uniquely determined by the dial that is being worn at the time, and the series is determined by the magnification of Shins 4 and Lens iQ. Therefore, it is unrealistic to have the CPU 12 memorize all the combinations of these factors; instead, it is necessary to memorize only factors such as the number of strokes of each character and the characteristics of the strokes. It is effective to input the command to the CPU 12 and obtain the desired information as a calculation result with a stored factor. In addition, in the above explanation, the pulse width of the video signal
Although the wave height is controlled, if a binarization circuit is provided in the waveform shaping circuit 7 to obtain a video signal with a constant wave height, only the pulse width, that is, the line thickness of the reproduced character image can be controlled. By doing so, it becomes possible to eliminate variations in visual density. Further, the method of the present invention is effective as a countermeasure against fluctuations in the video signal due to changes in the light amount of the light source 2. Furthermore, the method of the present invention can be applied not only to so-called automatic machines but also to manual phototypesetting machines, and can also be applied to character generating parts of ticket issuing machines, printers, display devices, etc., and can be used in various ways within the scope of the invention. changes can be made freely. As explained above, according to the method of the present invention, by controlling the target potential, the pulse width and wave height of the video signal supplied to the CRT are controlled, and the line thickness and brightness of the reproduced character image are adjusted. As a result, high quality reproduced character images with visual density variations removed can be obtained.

For a brief explanation of the drawings, FIG. 2 is a block diagram showing the configuration of a phototypesetting machine to which the imaging system of the present invention is applied.

1... Dial, 2... Light source, 5... Image pickup tube, 9. ….

・CRT, 13...Sensitive material, 12...CPU, 13...
...Control circuit t Tortoise 4...Ignition control circuit. Figure 1 Figure 2

Claims (1)

[Claims] 1 Select and irradiate desired characters from a dial containing an arbitrary number of characters, project and store them on an image pickup tube whose afterimage has been removed in advance, and read out and scan the obtained video signal on a CRT.
In a device for reproducing a desired character image by supplying
Each character is reproduced on the CRT by changing the target bias voltage of the image pickup tube when projecting the desired character and during readout scanning, and controlling the pulse width and wave height of the resulting video signal. An imaging method characterized by adjusting the line thickness and brightness of a character image to prevent visual variations in brightness.