JPH05268640A - Method of direct-readably displaying character or the like on observation screen for waveform of television signal - Google Patents

Abstract

PURPOSE:To display characters, symbols, etc., for displaying the waveform of television signals direct-readably in addition to the fundamental waveform of the television signals in the case of measuring the characteristics of a telecamera system including an optical system. CONSTITUTION:Characters or the like are displayed direct-readably on the observation screen for the waveform of the television signals by adding signal components for displaying the characters or the like formed by the components whose gradation is changed successively along a direction intersecting orthogonally with the scanning direction of the one side of the telecamera in addition to the fundamental television signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for directly displaying characters and the like on a waveform observation screen of a television signal. A television camera used in a broadcasting station has a high-performance design including an optical system and an electric system in order to exhibit the performance required for broadcasting. For example, in relation to image quality, excellent sensitivity (SN ratio), spectral sensitivity (color reproduction), photoelectric conversion characteristics (gradation characteristics), and static / dynamic resolution characteristics (detail reproduction) are required. It is said that it is desirable that there be few false signals that cause deterioration. When using a television camera, various measuring means are used to accurately grasp these performances and always adjust them to the best condition.

Among these characteristics, many test charts are used for measuring the performance of a television camera including an optical system. These charts are imaged, and required measurement or adjustment is performed while optically and electrically evaluating.

[0003]

2. Description of the Related Art An example of such a test chart is an ITE inmega cycle chart for measuring the horizontal resolution of a television camera and a video circuit system as shown in FIG. This chart shows 0.5MHz of video frequency band
The vertical black and white stripes corresponding to z to 6 MHz are arranged in 9 blocks, which is an important chart for understanding the basic performance of the television camera. A numerical value indicating the corresponding frequency (MHz) is printed below each block.

When an image of a conventionally used ITE in-megacycle chart is taken by a television camera under test and its output is observed by a waveform such as an oscilloscope, a square wave or a trapezoid that fluctuates between a white level and a black level of the chart is observed. Alternating waveforms such as waves are observed. On the basis of such an observed waveform, various characteristics of the optical system, the electronic system, etc. are measured.

In the waveform observation using this type of chart, the waveform can be observed, but the frequency and reference code of the waveform observed at each time cannot be seen. For example, when expanding the range of the horizontal axis when observing a waveform, it is necessary to partially observe the waveform, which makes it difficult to determine which portion is being viewed. In addition, when the observed waveform is saved and viewed later, it is difficult to determine which part of the observed waveform is being viewed.

For example, in the conventional in-megacycle chart of FIG. 5, there is a small frequency display under the black and white vertical stripes, but these numbers are merely lines as a video signal, and the video monitor. Direct reading is not possible without consideration such as adding.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for displaying directly read characters or the like on a waveform observation screen of a television signal used when measuring the characteristics of a television camera.

[0008]

According to the present invention, in addition to an original TV signal, a signal representing a character or the like formed by a component whose gradation is sequentially changed along a direction orthogonal to the scanning direction of a TV camera. The method is characterized in that a character or the like is displayed so as to be directly readable on a waveform observation screen of a television signal by adding a component.

In this case, a series of signals whose gradations sequentially change are adapted to desired letters, numbers, symbols, etc., so that these letters, numbers, symbols, etc. can be displayed in addition to the signal waveform. Can be read directly in.

[0010]

According to the method of displaying directly read characters on the television signal waveform observation screen according to the present invention, characters and symbols such as alphabets and numbers which can be directly read are displayed on the signal waveform observation screen of the oscilloscope or synchroscope. Is displayed.
Signals corresponding to these characters and the like can be sequentially added in the observation chart by components having different gradations.
Alternatively, it can be achieved by electronically generating the signal using a suitable signal generator having a well-known structure and adding it to the television signal.

By adding such characters so as to be directly readable, a great convenience can be obtained in order to eliminate an error associated with waveform observation and to perform an appropriate characteristic measurement.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of displaying characters and the like in a directly readable manner on a waveform observation screen of a television signal according to the present invention will be disclosed below based on embodiments. FIG. 1 shows an embodiment in which the present invention is applied to a horizontal resolution measurement chart of a television camera. In this embodiment, black and white vertical stripes were printed as digital image data based on a gradation of 12 dots per 6 MHz cycle. In this case, the relationship between each digital value, the ink density, the reflectance, etc. was quantitatively confirmed, and the manufacturing was performed while paying attention so that the light and shade at the black and white boundary would be sinusoidal. As a result, a sharp change in the signal waveform is prevented and a sine wave is obtained. Computers are used in many fields of calculation and production of these mutual relationships.

1, at the appropriate place to the right of the black and white vertical stripes,
The numbers 2, 3, and 6 are drawn in such a manner that the gradation changes sequentially from top to bottom. That is, these numbers are
The top is light gray and the bottom is dark gray, and in the middle of these, the gradation difference changes sequentially. In many fields of calculation and production of mutual relationships in this case, computers are used as in the case of black and white stripes.

FIG. 2 is a black and white vertical stripe pattern corresponding to 1 MHz of the chart of FIG. 1 and the gradation drawn from the light gray to the dark gray, which is drawn on the right side, from the upper gray to the lower gray. It is an enlarged display of the part showing the number 1. When this chart is imaged by a TV camera, X
While scanning in the Y direction, the Y direction is also scanned at a predetermined ratio to form a frame.

By scanning a black and white vertical stripe pattern in the X direction, an alternating waveform varying from the white level to the black level by the number of stripes can be obtained. This state is the same from the top to the bottom of the black and white vertical striped pattern, so it always overlaps, so
The television signal always draws one alternating locus. On the other hand, in the part of the numeral 1, a signal of a level corresponding to light gray is obtained in the scanning of the top part, and as the scanning line moves in the Y direction, the signal gradually shifts to a signal of a dark level and becomes the maximum. Reach the bottom. Therefore, as a result, the directly readable numeral 1 is formed on the monitor screen.

That is, X, Y of the black and white vertical stripe pattern portion
The signal obtained by the two-dimensional scanning in the direction has an alternating waveform in which three cycles are repeated with the amplitude from the white level to the black level. On the other hand, from the part of the number 1 in which the gradation changes sequentially from the top to the bottom, the directly readable number 1 distributed from the light gray level to the dark gray level by the two-dimensional scanning in the X and Y directions is displayed. Will be formed.

The numbers thus formed are the states of the black and white vertical striped pattern, here the numbers representing the frequency.
Other character symbols and the like can be added in the same manner. The same applies to 2, 3 and 6 MHz. Figure 3
[Fig. 3] is an example of an observed signal waveform when the chart shown in Fig. 1 is imaged by a television camera. 0.5MHz to 6MHz
The oscillogram of the alternating waveform of 9 blocks with vertical stripes is displayed. 1, 2 ,,,
It can be confirmed that the numbers 3 and 6 are displayed in a directly readable manner.

Such a numerical value display exists near the waveform of the corresponding frequency even when the range of the horizontal axis in FIG. 3 is expanded, and the value can be directly read, which facilitates the waveform observation. , Effective to eliminate errors in testing or adjustment. The change in gradation from the top to the bottom of the numbers representing the frequencies in the horizontal resolution test chart of FIG. 1 is calculated by using a computer, and printing is performed based on the result. However, the same effect can be obtained also by the electronic signal generating means configured to sequentially generate the grayscale signal based on the calculation result of such a computer.

FIGS. 4 (a), (b) and (c) are examples of the oscillogram obtained in this way, and FIG. 4 (a) shows the numeral 1 at 0.5 MHz and 1 MHz,
Figure (b) shows the number 2 at 1.5MHz and 2MHz, and Figure (c) shows 2.5MHz and 3MH.
The numeral 3 is indicated by z. In both of the above-described examples, the numerical value indicating the frequency is added to the horizontal resolution test chart, but similarly for letters and symbols other than such numbers, such as letters and symbols with different gradations. It is also possible to add it as a symbol and display it on the signal waveform observation screen in a directly readable state.

Further, in the vertical resolution test,
By exchanging the X-axis and the Y-axis, similarly directly readable characters and symbols can be displayed.

[0021]

According to the present invention, desired characters, numbers, symbols, etc. can be added in a directly readable state in addition to the signal waveform obtained by the television camera. as a result,
Not only when observing the waveform, but also when measuring and adjusting the characteristics of the TV camera system, including the optical system, the corresponding characters, numbers, and symbols are displayed near the waveform, making it easy to check, eliminating errors, and speeding up. Various observations and adjustments are possible, and many conveniences can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a horizontal resolution measurement chart for a television camera that can be applied to a method according to the present invention.

2 is an explanatory diagram of a main part of the horizontal resolution measurement chart for a television camera shown in FIG.

FIG. 3 is an oscillogram according to a first embodiment of the method according to the invention.

4 (a), (b), (c) are oscillograms according to a first embodiment of the method according to the invention.

FIG. 5 is an example of an in-megacycle chart for measuring horizontal resolution of a television camera according to the related art.

Claims (3)

[Claims] 1. In addition to the original television signal, a signal component representing a character or the like formed by a component whose gradation is sequentially changed is added along a direction orthogonal to one scanning direction of the television camera. Characteristic method to display characters etc. on the TV signal waveform observation screen so that they can be read directly. 2. A signal component representing a character or the like formed by the component whose gradation changes sequentially is obtained by capturing an image of a character whose gradation changes sequentially printed on a chart by a television camera. Claim 1 characterized by the above-mentioned.
The method of displaying characters etc. on the waveform observation screen of the TV signal described in [4] so that they can be read directly. 3. The waveform of a television signal according to claim 1, wherein a signal component representing a character or the like formed by the component whose gradation is sequentially changed is obtained by an electronic signal generating means. A method of displaying characters on the observation screen so that they can be read directly.