JPH01319022A - Silver salt film type camera - Google Patents

Abstract

PURPOSE:To assure the image under the same photographing conditions as with a silver salt film by displaying the image photographed on the silver salt film on a display means via a solid state image pickup element and amplifying the image signal from the solid state image pickup element according to the sensitivity of the silver salt film. CONSTITUTION:The solid state image pickup element 6 to which the optical image of a subject imaged on the silver salt film 5 is inputted is provided and the image signal from the element 6 is amplified. The amplified image signal is reproduced and displayed; in addition, the sensitivity of the silver salt film 5 is detected and the gain of an amplifying means 7 is changed according to the detected sensitivity. The image of the same aperture and shutter speed as the photographing conditions of the silver salt film 5 is, therefore, displayed on a monitor 13. Prior exact checking of the photographing state to the silver salt film 5 is executed in this way.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to an improved technology for silver halide film type cameras.

<Prior art> In a silver-halide film type camera, imaging is performed by operating the shutter while viewing the subject through an optical viewfinder and forming an optical image of the subject on the silver-halide film using a No. 4 lens. There is.

<Problems to be Solved by the Invention> However, in conventional silver-halide film cameras, the subject is viewed through the optical viewfinder while taking pictures; There was a problem in that there was a difference between the shape and the shape on the silver halide film, and it was not possible to confirm the image that met the needs of the person in the darkest position.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a silver halide film type camera that can secure images that meet the needs of a photographer.

Means for Solving the Problems> For this reason, the present invention provides a silver halide film camera that
a solid-state image sensor into which an optical image of a subject formed on a silver halide film is input; an amplifying means for amplifying the image signal from the solid-state image sensor; a display means for reproducing and displaying the amplified image signal; The apparatus includes a sensitivity detecting means for detecting the sensitivity of the silver halide film, and a gain changing means for changing the gain of the amplifying means according to the detected sensitivity.

Then, the image of the subject to be photographed on the silver halide film is displayed on the display means, and the image signal of the solid-state image sensor is amplified according to the sensitivity of the silver halide film to produce an image under the same photographing conditions as the silver halide film. I was able to secure it.

<Example> An example of the present invention will be described below based on FIGS. 1 and 2.

In FIG. 1, an optical image of a subject from an optical lens (not shown) enters a half mirror 3 via a shutter 1 and an iris 2, and the optical image is transferred from the half mirror 3 to a silver halide film via a light shielding plate 4. 5 and is also imaged on a CCD 6 as a solid-state image sensor. The CCD 6 photoelectrically converts the formed optical image and outputs an analog image signal to a Y/C separation circuit 8 via an amplifier circuit 7, which will be described later.

The Y/C separation circuit 8 separates the analog image signal into a luminance signal including a synchronization signal and a color signal, and outputs these signals to an A/D converter 9. The A/D converter 9 has Y/
The signal from the C separation circuit 8 is A/D converted. here,
Y/C separation circuit 8 and A/D converter 9 constitute signal processing means.

The output terminal of the A/D converter 9 is connected to the input terminal of a display memory (for example, a dual port image memory) 10 that stores digital image data. Digital image data stored in display memory 10 is output to D/A converter 11. The D/A converter 11 performs D/A conversion on the digital image data and then outputs the data to the signal processing circuit 12 . The signal processing circuit 12 processes the image information and outputs it to a monitor 13 as a display means composed of a liquid crystal. The monitor 13 reproduces and displays the signal-processed image information on the screen. Here, the monitor 13 serves as a finder.

The system controller 14 receives signals from a release switch, etc., and performs opening/closing control of the shutter 1, etc. The synchronization signal generation circuit 15 is designed to generate a synchronization signal for synchronizing the operations of various devices.

The driver 16 is configured to generate a charge pulse signal (hereinafter referred to as SG pulse) and a clock to the CCD 6 in synchronization with the signal from the synchronization signal generating circuit 15.

The system controller 14 has a release switch (
When Sl (not shown) is turned on, the shutter 1 is kept open and the accumulation time of the light receiving section of the CCD is controlled by electronic shutter operation. Further, when the release switch 32 is turned on, the system controller 14 once closes the shutter 1 and then controls the opening and closing of the shutter 1 according to the set shutter speed. Here, the accumulation time is set to be sufficiently long compared to the operation of the electronic shutter shutter 1.

Further, the display memory 10 becomes write-enabled immediately after photographing and holds the photographed screen.

Here, a detection signal is input to the system controller 14 from a DX code detector (not shown) serving as a sensitivity detection means for reading and detecting the sensitivity, number of sheets, etc. displayed on the silver halide film by the DX code, and the system controller 1
4 changes the gain of the amplifier circuit 7 in accordance with the detected sensitivity of the silver halide film. Therefore, the system controller 14 constitutes gain changing means.

Next, the specific configuration of the amplifier circuit 7 will be explained based on FIG. 2.

The image signal of the CCD 6 is input to the first amplifier 21, and the first
The output of the amplifier 21 is input to a first gain changeover switch 23 via a variable resistor 22.

The input terminal of the second amplifier 24 is grounded via a first fixed resistor 25, and an A terminal is formed at the input terminal of the second amplifier 24, with which the contact of the first gain changeover switch 23 contacts. The output of the second amplifier 24 is input to a second gain changeover switch 26.

The input terminal of the third amplifier 27 is grounded via a second fixed resistor 28, and an A terminal is formed at the input terminal of the third amplifier 27, with which the contact of the second gain changeover switch 26 comes into contact. The output of the third amplifier 27 is input to a third gain changeover switch 29.

The input terminal of the fourth amplifier 30 is grounded via a third fixed resistor 31, and the input terminal of the fourth amplifier 30 is formed with an A terminal to which the contact of the third gain changeover switch 29 comes into contact. The output of the fourth amplifier 30 is input to the Y/C separation circuit 8. Further, the first to third gain changeover switches 23, 26, and 290B terminals are connected to the output terminal of the fourth amplifier 30.

Note that 32 and 33 are capacitors.

And the first to third gain changeover switches 23.26°2
9 is switched and controlled by the system controller 15 according to the sensitivity of the silver halide film 5. Specifically, when the sensitivity of the silver halide film 5 is Is○100, the first to third gain changeover switches 23.26°29 are both in contact with the B terminal, and the image signal from the first amplifier 21 is sent to the Y/C separation circuit. 8
is input. Further, at 150200, the first gain changeover switch 23 is controlled to switch to the A terminal, and the image signal is input to the Y/C separation circuit 8 via the first amplifier 21 and the second amplifier 24. Further, when 15O400, the first and second gain changeover switches 23.26 are switched to the A terminal and controlled, and the first amplifier 21.26 is switched to the A terminal. The image signal is input to the Y/C separation circuit 8 via the second amplifier 24 and the third amplifier 27. Furthermore, when l5O1600, the first
- The third gain changeover switches 23, 26, and 29 are all switched to the A terminal, and the image signal is output from the fourth amplifier 30 to Y/
The signal is input to the C separation circuit 8.

Next, the action will be explained.

When the release switch 31 is turned on, the shutter 1 opens while the electronic shutter controls the CCD storage time to correspond to a predetermined shutter speed.

At this time, the light shielding plate 4 is maintained in a closed state. Further, the first to third gain changeover switches 23, 26, and 29 are controlled depending on the sensitivity of the silver halide film 5, and the gain of the amplifier circuit 7 is adjusted.

During exposure due to the opening operation of the electronic shutter, the output of the SG pulse from the driver 16 to the CCD 6 is prohibited, and the transfer operation is stopped. When the exposure is completed by closing the electronic shutter, the driver 16 sends the CCD
The output of the SG pulse to the CCD 6 is permitted, and the operation of transferring the image signal from the CCD 6 to the Y/C separation circuit 8 via the amplifier circuit 7 is started. The image signal at this time is input to the display memory 10 via the A/D converter 9 and stored therein. The image signal recorded in the display memory 10 is output to the monitor 13 via the D/A converter 11 and the signal processing circuit 12, and is displayed on the monitor 13. This operation is repeated during 81 ON periods.

Since the image signal is displayed on the monitor 13 in this manner, the image can be displayed as a moving image on the monitor 13, so that the monitor 13 can be effectively used as a finder.

Furthermore, when driving a normal CCD, the accumulation time is at most 1/60.
This method uses memory, so 1/15 second or 1/8 second is also possible.

At this time, since the gain of the amplifier circuit 7 is set to increase as the sensitivity of the silver halide film 5 increases, an image with the same aperture and shutter speed as the photographing conditions of the silver halide film 5 is displayed on the monitor 13. , the photographing condition on the silver halide film 5 can be accurately confirmed in advance.

Furthermore, even in backlit situations, the photographing conditions on the silver halide film 5 can be accurately confirmed.

When the release switch 82 is turned on, the shutter 1 is once closed, and then the opening and closing of the shutter 1 is controlled according to the set shutter speed. At this time, the light shielding plate 4 is opened. This allows the optical image of the subject to be transferred to the silver halide film 5.
imaged and recorded. Further, an image substantially the same as the image recorded on the silver halide film 5 is recorded in the display memory 1o via the CCD 6. At this time, the electronic shutter sweeps out the charge that was accumulated when the shutter 1 is closed for the first time, and continues to open the electronic shutter (prohibits the SO pulse) until after the shutter 1 is opened (from the front to after it is closed). Writing to the read memory is performed when 31 is ON.

Immediately after shooting, the display memory 10 is set to write enable, and the captured image information is input to the monitor 13 via the D/A converter 11 and signal processing circuit 12, and is input again to the display memo. and is stored, thereby
Since an image substantially similar to the image recorded on the silver halide film is reproduced and displayed as a still image on the monitor 13, it is possible to immediately judge whether the recording condition on the silver halide film is good or not and take another photograph.

Also, at this time, the gain of the amplifier circuit 7 is set according to the sensitivity of the silver halide film 5.
You can check the image on the monitor 14 under the same shooting conditions.

<Effects of the Invention> As explained above, the present invention is a silver halide film type camera in which an image taken on a silver halide film is displayed on a display means via a solid-state image sensor, so that it can be easily displayed even when backlit. Also, the photographed image of the silver halide film can be accurately confirmed by the display means. Furthermore, since the image signal from the solid-state image sensor is amplified in accordance with the sensitivity of the silver halide film, it is possible to check the image on the display means under the same photographing conditions as the silver halide film.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram of the same essential parts.

Claims (1)

[Claims] A silver-halide film camera includes a solid-state image sensor into which an optical image of a subject formed on the silver-halide film is input, an amplification means for amplifying the image signal from the solid-state image sensor, and reproduction of the amplified image signal. A silver halide film comprising a display means for displaying a display, a sensitivity detection means for detecting the sensitivity of the silver halide film, and a gain changing means for changing the gain of the amplification means according to the detected sensitivity. expression camera.