JPH01243674A - Scanning method for telecine equipment and telecine equipment - Google Patents

Abstract

PURPOSE:To improve the life of a CRT and the S/N of a picture signal by performing vertical scanning as moving a horizontal scanning line in the same direction as the traveling direction of a film from the bottom part toward the upper part of a film frame in a case that the film frame is scanned by a flying spot scanning light source (CRT). CONSTITUTION:In the case that the film frame is scanned by the CRT 1, the scanning line is moved in the same direction as the traveling direction of the film 4 from the bottom part toward the upper part of the film frame. Namely, during the traveling time of the film to occupy the major part of a whole period to scan the film 4, the almost whole area of the luminous surface 1a of the CRT 1 in a vertical direction is vertical-scanned. Accordingly, there is no possibility that a burnt blur is generated on the luminous surface on account of the concentric use of only the special narrow range of the luminous surface. Thus, the life of the CRT 1 can be extended, and besides, because the quantity of light of scanning light can be increased, the S/N p of the picture signal obtained by photoelectric conversion can be improved all the more.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an improvement in a telecine device that converts a photographed film screen of a movie or the like into a television signal.

"Prior art" As shown in Fig. 2, a flying spot scanning light source (for example, CRT)
Light (referred to as scanning light) 2 from 1 is imaged on a film 4 such as a movie through an imaging lens 3, and the transmitted light is incident on a dichroic mirror 6 through a lens 5, where the three primary colors are Light, i.e. red light 1 m, green light m and blue light i
It is decomposed into B. Each light enters a photoelectric converter 7 and is converted into an electric signal, and then converted into a digital signal via an A/D converter 8 and stored in an image memory (comprised of RAM) 9. Ru. The stored signal is appropriately read out in a format compatible with standard television signals and converted into an analog signal (video signal) via a D/A converter 10. Writing and reading from the image memory 9 is controlled by a memory control circuit 11. The above A/D converter 8, image memory 9, D/A converter 10 and memory control circuit 11 are used for each color video signal generation circuit 12B.
, 12o.

12n is configured.

When scanning one frame 20 of a stationary film 4 (an extremely short period of time for storing the still image signal of that one frame in the image memory 9), the frame 20 is scanned from right to left as shown in FIG. 3A. It is scanned horizontally and vertically from top to bottom.

Since the scanning light 2 is inverted by the imaging lens 3, the scanning light 2 is horizontally scanned from left to right and vertically scanned from bottom to top on the flying spot scanning light source 1. Piece 20 (its vertical and horizontal dimensions are aXb
In order to scan the flying spot scanning light source 1, the entire surface of the surface from which the scanning light 2 is emitted (referred to as the optical surface, whose vertical and horizontal dimensions are AXB) is used.

Next, the case of scanning a running film will be described. Typically, the film is run in a direction 21 from the bottom of the frame upwards at a speed of 24 frames/second, 30 frames/second, or the like. If scanning of one frame 20 indicated by a solid line is started from above, at the end of scanning, that frame moves to the position indicated by a dotted line in the figure, so the first horizontal scanning line 20a and the last horizontal scanning line 20b
The distance d between the frame and the frame is the length obtained by subtracting the travel distance e in the scanning period for one frame from the vertical dimension a of the frame. That is, it is expressed as d a - e (1). Correspondingly, the vertical scanning amplitude on the flying spot scanning light source 1 is D−dxΔ=:! xA=(1--)Aa a
a (2). If 525 horizontal scanning lines correspond to 1 frame, then the running film 4
When scanning, those horizontal scanning lines are compressed into a range of the vertical dimension on the optical surface 1a. Dawn surface la where the running speed of the film 4 is 24 frames/second or 30 frames/second
The vertical scanning amplitudes above are the vibrations when the film is stationary.
It is compressed to about 25% or 10%.

``Problem to be solved by the invention'' The period of scanning a still film is extremely short, during the preparation period before continuous running of the film, a still image signal of a small number of frames (for example, 1 frame) is stored in memory. It is limited in time and is small compared to the total usage time, and most of the time is spent scanning the film during continuous running. Moreover, during that period, the amplitude of the vertical scan on the flying spot scanning light source 1 is compressed to a special range of about 10 to 25% of the vertical dimension of the light surface, and within that range, for example, 525 horizontal scans are performed. Because only a narrow special area is used intensively, only the fluorescent surface in that area becomes severely burnt, and uneven burns appear in a relatively short period of time, resulting in a shortened lifespan of the CRT. there were.

As the light intensity of the scanning light 2 increases, the life of the CRTl becomes shorter, so due to the above reasons, the light intensity must be kept as low as possible.For this reason, the S/N ratio of the image signal obtained by photoelectric conversion becomes low. There were drawbacks.

An object of the present invention is to solve the above-mentioned drawbacks and improve the life of the CRT and the S/N ratio of the image signal.

"Means for Solving the Problems" According to the scanning method of a telecine apparatus of the present invention, a film screen is scanned by a flying spot scanning light source.

The scan line is moved from the bottom of the film screen to the top in the same direction as the film travel direction.

In the telecine apparatus of the present invention, the scanning of the film screen by the flying spot scanning light source is performed by vertical scanning by moving the horizontal scanning line from the bottom to the top of the film screen in the same direction as the running direction of the film. When scanning the
The vertical scanning amplitude is reduced in accordance with the running speed when the film is run and scanned, and the obtained video signal for one screen is stored in an image memory, and a still image signal is obtained from the image memory. It will be done.

Embodiment In order to provide an explanation of the scanning method of the telecine apparatus of the present invention, portions in FIG. 1 corresponding to those in FIG. Further, FIG. 2 can be applied as is as a block diagram of an embodiment of the telecine apparatus of the present invention. In this invention, the film screen is scanned vertically by the flying spot scanning light source (CRT) 1 by moving a horizontal scanning line from the bottom to the top of the film screen in the same direction as the film 40 running direction. Of course, in order to enable vertical scanning of the film screen, the vertical scanning speed is set at the film 40.
It is made larger than the traveling speed. In FIG. 1B, when the frame 20 of the film 4 is at the position indicated by the solid line, if scanning is started from the bottom of the screen, the frame will have moved to the position indicated by the dotted line at the end of scanning. Film 4 is scanned by scanning light 2.
The vertical scanning distance @d at the position is the sum of the vertical dimension a of the frame and the travel distance e of the film in the scanning time of one frame. That is, d = a -1-e
(3). The vertical scanning distance d at this position of the film 4 is made equal to the vertical dimension A on the optical surface 1a.

When scanning one piece in a stationary state, Fig. 1A
As shown in , the amplitude of vertical scanning on the optical surface 1a is compressed to X with respect to the vertical dimension a of the piece.

This dimension X is given by. For example, if e/a'::3/4, then =057XA. (The width of the vertical scan on the optical surface 1a during film running as described in the prior art is (2
), if e/a = 3/4, then D = 0.
25 x A, which is slightly smaller than half of the above. )
In this way, the transmitted light obtained by scanning the film 4 from bottom to top enters the guichroic mirror 6 via the condenser lens 5 and is separated into three primary colors, as shown in FIG. Each light beam is converted into an electrical signal and then written into the image memory 9. The signals written in the image memory 9 are read out in a standard preview format that scans the screen vertically from top to bottom, unlike the order in which they were written.

"Effects of the Invention" According to this invention, when the film is running (which occupies most of the entire period when the film is running), the flying spot scanning light source l
The entire vertical dimension of the optical surface ia is vertically scanned. Therefore, there is no need to concentrate on a narrow special area of the light surface for the majority of the period of use, unlike conventional methods, and there is no risk of uneven burning on the light surface, greatly extending the life of the light source. be able to.

In addition, since there is no risk of creating uneven burns, the amount of scanning light can be increased compared to conventional methods, and the S/N ratio of the image signal obtained by photoelectric conversion can be improved accordingly. .

When scanning film frames in a stationary state, the amplitude of the vertical scanning of the optical plane is compressed, but such a period accounts for a very small proportion of the total operating time and the degree of compression is small. Since the size is low (for example, the size after compression accounts for 50 to 60% of the size A before compression), there is no fear of uneven baking as in the conventional case.

Note that the flying spot scanning light source that can be used in this invention is C.
In addition to the RT type, scanning may be performed using light from a laser oscillator.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the principle of the optical system for explaining the scanning method of the telecine device of the present invention, FIG. 2 is a block diagram of the conventional telecine device and the present invention, and FIG. 3 is a diagram of the conventional telecine device. FIG. 2 is a perspective view of the principle of an optical system for explaining a scanning method.

Claims (2)

[Claims] (1) A scanning method for a telecine device in which scanning of a film screen by a flying spot scanning light source is performed by vertical scanning by moving a horizontal scanning line from the bottom to the top of the film screen in the same direction as the running direction of the film. (2) When scanning a film screen with a flying spot scanning light source, vertical scanning is performed by moving the horizontal scanning line from the bottom to the top of the film screen in the same direction as the film running direction, and when scanning a stationary film. To do this, the amplitude of vertical scanning is reduced in accordance with the speed at which the film is run and scanned, and the resulting video signal for one screen is stored in an image memory, and a still image is generated from the image memory. Telecine equipment to obtain the signal.