JPH042536Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an image reproduction system suitable for use in reproducing images recorded on photographic film.

(Prior art) A video camera exchanges optical information about a subject into an electrical signal, and converts the exchanged image signal (video signal) into an electrical signal.
It is used to reproduce a visible image on a display device such as a CRT. As an imaging means used in a video camera, for example, in addition to an imaging tube such as an image orthicon or a saticon, a solid-state imaging device such as a CCD is used.

By the way, among this type of video cameras commercially available, there is a video camera with a negative/positive reversal function. This video camera with a negative/positive reversal function is usually equipped with a negative/positive switch, and when shooting negative film, set the negative/positive switch to the negative side and attach the film adapter to the camera body. The negative film is illuminated from the back side, the image light of the film obtained is converted into an electrical signal by an imaging means, and the converted photoelectric conversion signal is transmitted to the negative/
The positive image is inverted, and the resulting video signal can be viewed as a normal image on a CRT screen. On the other hand, when shooting positive film,
Set the negative/positive switch to the positive side, shine light on the positive film from the back, convert the resulting image light from the film into an electrical signal using the imaging means, and display the resulting video signal as it is on the CRT screen. It is now possible to view it as an image.

(Problem to be solved by the invention) When a negative film is shot using a conventional video camera with a negative/positive reversal function of this type and displayed on a CRT screen or printed on a printer, the amount of light from the film adapter is constant. As a result, there are usually parts that are white or black. In order to eliminate such problems, it is necessary to equip the video camera with an auto iris mechanism and a manual iris mechanism, and to adjust the amount of light on the video camera side. It is convenient that a normal image can be obtained by manually adjusting the iris (aperture) to the optimum size. However, if a video camera is equipped with both an auto iris and a manual iris mechanism, the device becomes complicated and the camera body becomes larger.
It ends up being expensive.

The present invention has been devised in view of these points, and its purpose is to realize an image reproduction system that is inexpensive and has a simple configuration.

(Means for Solving the Problems) The present invention solves the above-mentioned problems in an image reproduction system in which image light obtained by irradiating a film with a light source is received by a video camera and the image is reproduced by a CRT. This system is characterized in that the aperture of the video camera is fixed during image reproduction, and the quality of the reproduced image is adjusted by adjusting the amount of illumination light.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a mechanical configuration diagram showing an embodiment of the present invention. This invention consists of a video camera and a film adapter. In the figure, 1 is a light source, 2 and 3 are lenses, 4 is an iris located between lenses 2 and 3, 5 is a film on which a positive or negative image is recorded, and 6 is in contact with the film. or an optical filter arranged closely. The above light source 1, lenses 2 and 3, iris 4,
The film 5 and the optical filter 6 constitute a film adapter. The aperture amount of the iris 4 can be adjusted manually.

7 and 8 are lenses that receive the image light from the film 5; 9 is an iris placed between these lenses 7 and 8; and 10 is a converter that converts the image light of the image recorded on the film 5 into an electrical signal. It is an imaging means for Lenses 7, 8, iris 9 and imaging means 1
0 constitutes a video camera section. The iris 9 of the video camera section, unlike the iris 4 of the film adapter section, has a structure in which the aperture amount cannot be manually adjusted, and can only operate as an auto iris or a fixed iris. The imaging means 10 is configured to invert the photoelectric conversion output or directly amplify the photoelectric conversion output using a negative/positive changeover switch (not shown) and output a video signal. The imaging means 10 may be, for example, an imaging tube such as the image orthicon described above, or a circuit system using an imaging plate using a solid-state imaging device such as a CCD. The operation of the device configured in this way will be explained below.

A case where the film 5 is a negative film will be explained. Light is irradiated from a light source 1 to the back side of a negative film 5. Light emitted from a light source 1 is irradiated onto a film 5 via a lens 2, an iris 4, a lens 3, and an optical filter 6. In this case, the aperture of the iris 4 can be manually adjusted, and the amount of light irradiated onto the film 5 from the back side is adjusted to an optimum value by turning an aperture adjustment knob (not shown).

Image light is generated on the film 5 by the exposure to light. This image light enters the video camera section. That is,
The image light is incident on the video camera body through the objective lens 7. Here, the video camera has a negative/positive switch (not shown) and an auto iris/
A fixed iris changeover switch (not shown) is provided, and in this case, the negative/positive changeover switch is set to the negative side, and the auto iris/fixed iris changeover switch is set to the fixed iris side. That is, when a film adapter is attached to the video camera and film photography is performed, the auto iris/fixed iris switching switch is set to the fixed iris side, and the aperture amount of the iris 9 is fixed.

As described above, according to the present invention, the iris 9 is fixed at a predetermined aperture amount during film photography. Unlike conventional devices, there is no need for a mechanism that allows manual adjustment, so the number of mechanical parts can be reduced, and no adjustment knobs are required. Therefore, the device can be made compact and inexpensive. Using an open iris as the fixed iris further simplifies the mechanism.
However, according to the present invention, since it is not possible to adjust the amount of light on the video camera side when shooting film, the iris 4 on the film adapter side is configured to be manually adjustable so that the amount of light incident on the film 5 can be adjusted. ing.

As a result, an optimal amount of image light reaches the imaging means 10. Since negative information is input to the image pickup means 10 from the negative/positive changeover switch, the image pickup means 10 photoelectrically converts the image light and then performs negative/positive inversion to create a video signal. The video signal obtained in this way is transmitted to a display device such as a CRT (not shown).
reproduced as a visible image above. In the system shown in the figure, since the light amount is set to an optimum value on the film adapter side, a normal image can be reproduced without causing blown-out highlights or blown-out shadows.

Incidentally, a spring (not shown) is attached to the iris 9 used in the present invention, and the iris 9 is normally closed by the force of this spring. Therefore, in order to open the iris 9, it is necessary to forcibly apply a force that overcomes the force of the spring. This force is provided, for example, by rotation of a motor. Second
The figure is an electrical circuit diagram showing one embodiment of an iris drive system. Comparator U compares the video signal and reference voltage Es. Then, the output of the comparator U drives the transistor Q via the resistor R. transistor Q
A motor is connected to the collector as a load. The reference voltage Es is created by dividing the power supply voltage Vcc using a variable resistor, so that it can be varied. The operation of the circuit configured in this way will be explained below.

In the figure, when the level of the video signal becomes low,
Comparator U drives transistor Q to turn on the motor and open the iris. On the other hand, when the video signal becomes large, the comparator U cuts off the transistor Q and closes the iris. In order to use such a drive system in the fixed iris mode, it is necessary to keep the transistor Q always on. For this purpose, a low level video signal may be used, or the reference voltage Es may be increased.

FIG. 3 is an electrical circuit diagram showing one embodiment of the iris drive system used in the present invention. Components that are the same as those in FIG. 2 are designated by the same numbers. In the figure, SW
is an auto iris/fixed iris changeover switch. The switch SW has an a contact side connected to the video signal side and a b contact side grounded. When the switch SW is connected to the a contact side, the auto iris mode is set, and when the switch SW is connected to the b contact side, the fixed iris mode is set. When the auto iris/fixed iris changeover switch SW is connected to the a contact side, a video signal is input, and the circuit shown in the figure becomes the same as the circuit shown in FIG. 2 and enters the auto iris mode. That is, the transistor Q is turned on and off depending on the magnitude of the video signal, and the iris 9
Opens and closes and automatically adjusts the light intensity.

Next, when the auto iris/fixed iris changeover switch SW is connected to the b contact side, the potential at the input point of the comparator U is grounded and always becomes lower than the reference voltage Es. As a result, transistor Q is always on and the motor is also always on. Therefore, the iris 9 controlled by the motor is always fixed at a predetermined opening amount. That is, the fixed iris mode is set.

FIG. 4 is an electrical circuit diagram showing another embodiment of the iris drive system according to the present invention. Components that are the same as those in FIG. 3 are designated by the same numbers. In the embodiment shown in the figure, the B contact side of the auto iris/fixed iris changeover switch SW is connected to the power supply voltage Vcc, and the A contact side is connected to the divided voltage value (reference voltage) Es of Vcc, and the video signal is directly input to the comparator U. are doing. In the circuit configured as described above, when the auto iris/fixed iris changeover switch SW is connected to the a contact side, the circuit shown in the figure becomes the same as that shown in FIG. 2, and becomes the auto iris mode. Next, turn on the auto iris/fixed iris switch.
When SW is connected to the b contact side, the potential at the relevant input point of comparator U is always higher than the video signal. As a result, transistor Q is always on and the mode is always on. Therefore, the iris 9 controlled by the motor is always fixed at a predetermined opening amount,
Fixed iris mode. In this fixed mode, it is convenient to use an open iris.

According to the present invention, simply by fixing the iris 9 in the fixed mode (especially in the open mode), the film 5 can be
Images recorded on can be played back on CRT. If the film adapter is separated from the state shown in the figure, the video camera functions as a single unit. In other words, it becomes a normal video camera and photographs the subject. In this case, set the auto iris/fixed iris switch to the auto iris side to automatically adjust the light amount.

Further, in the above description, an example is given in which a motor is used as the drive system for the iris, but the present invention is not limited to this, and other drive means such as a plunger or the like may be used.

(Effects of the invention) As explained in detail above, according to the invention,
When shooting film, a manual light intensity adjustment mechanism is provided on the film adapter side, and the iris on the video camera side is configured in a simple configuration that allows only fixed iris and auto iris modes, resulting in overall low cost and easy image playback. system can be realized.

[Brief explanation of drawings]

Fig. 1 is a mechanical configuration diagram showing an embodiment of the present invention, Fig. 2 is an electrical circuit diagram showing an embodiment of the iris drive system, and Fig. 3 is a diagram showing an embodiment of the iris drive system according to the present invention. Electrical Circuit Diagram FIG. 4 is an electrical circuit diagram showing another embodiment of the iris drive system. 1... Light source, 2, 3, 7, 8... Lens, 4,
9...Iris, 5...Film, 6...Optical filter, 10...Imaging means, U...Comparator, R...
...Resistor, Q...Transistor, SW...Auto iris/fixed iris selection switch.

Claims (1)

[Claims for Utility Model Registration] (1) In an image reproduction system in which image light obtained by irradiating a film with a light source is received by a video camera and the image is reproduced by a CRT, the aperture of the video camera is fixed during image reproduction. , an image reproduction system that adjusts the quality of reproduced images by adjusting the amount of illumination light. (2) The image according to claim 1 of the utility model registration claim, characterized in that the method for adjusting the amount of illumination light is that the amount of light is adjusted by an iris provided on the side of a film adapter docked to the video camera body. playback system.