JPH11326864A - Video camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display an image in a finder of a video camera with precision, and to limit power consumption. SOLUTION: A pickup signal obtained from a CCD image sensor 40 is processed by an image signal processing circuit 44. An image data for one full color screen is written in a buffer memory 49 by a display controller 48. An image data is read out for each color from the buffer memory 49, and a frame image is displayed on a liquid crystal display panel 25 for each color via an LCD driver 51. Synchronizing with this, R-LED28R, G-LED28G, B-LED28B emitting corresponding color light are turned on in a color sequence mode. A frame image in each color is magnified and observed via a convex lens 30, and a full color finder image is observable with after-image effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera using a full-color liquid crystal display panel as a viewfinder.

[0002]

2. Description of the Related Art With the practical use of solid-state imaging devices such as CCD image sensors, still or movie video cameras having a function of converting an optical image into an electric signal and storing it in various storage media have become widespread. I have. Recently, digital cameras have widely been used in which an image signal for one frame obtained from a solid-state image sensor is subjected to appropriate signal processing, then converted into digital data to be converted into image data, and stored in a built-in or detachable memory. Have been. The image data for one frame stored in the memory can be read out as needed. Images can be observed on the color LCD monitor built into the camera body, and the read image data can be transferred to a personal computer or printer. It can also add sophisticated image processing and create hard copies.

Many color liquid crystal monitors built in digital cameras use a TFT transmission type color liquid crystal panel having a diagonal size of about 1.8 to 2.5 inches, and a small white fluorescent lamp as a backlight. Is used. This color liquid crystal monitor is used not only for a viewfinder but also for observing a reproduced image.

[0004]

The conventional color liquid crystal panel has a structure in which liquid crystal dot segments are arranged for each pixel, and any one of R, G, and B micro color filters is superposed on each of them. Therefore, one pixel in full color is composed of three liquid crystal dot segments combined with R, G, B micro filters, and the resolution is reduced to one third of the total number of liquid crystal dot segments. Therefore, it is not possible to display the details of a reproduced image or a finder image with high definition, and when attempting to display a message in characters, the character size must be increased, so that the amount of information that can be displayed at once is small. was there.

Further, since any one of R, G and B color micro filters is superposed on each of the liquid crystal dot segments, the loss of light amount is large, and a high-luminance fluorescent lamp is required for the backlight. . However, a high-luminance fluorescent lamp consumes a large amount of power and places a heavy burden on a battery built into the camera, and it is difficult to use the fluorescent lamp for a long time.

The present invention has been made in view of the above-mentioned prior art, and provides a video camera using a finder image display means capable of displaying a full-color image at a high resolution and at the same time being extremely advantageous in terms of power consumption. The purpose is to do. The present invention can be equally applied not only to the above-described digital camera but also to a movie camera or a still camera that records an image signal after subjecting an image signal to appropriate signal processing as an analog signal.

[0007]

According to the present invention, in order to achieve the above object, a finder image display means serving as a view finder comprises: a liquid crystal display panel in which transmission type liquid crystal dot segments are two-dimensionally arranged; A light source that sequentially emits three types of basic color light from the back side, and an image signal for each basic color light is sequentially and repeatedly supplied to the liquid crystal display panel to switch the transmission density of the liquid crystal dot segment for each basic color light and synchronize with this. Display driving means for driving the light source so that the three kinds of basic color lights blink repeatedly and sequentially, so that an image displayed on the liquid crystal display panel can be magnified and observed from an eyepiece window by an eyepiece optical system. It was done.

Various light sources can be applied to the light source, and a white light source can be used if a color filter is provided in front of the light source itself. In order to further reduce the size, it is preferable to use three types of light emitting diodes that emit red, green, and blue light, respectively. It is preferable that the cycle of repeatedly supplying the image signal for each basic color light to the liquid crystal display panel and the blinking cycle of each light emitting diode be set to 1/16 second or less. As a result, a full-color image of at least 16 screens can be displayed on the liquid crystal display panel per second, and a continuous color image without flicker can be observed from the eyepiece window.

The display driving means is provided with a buffer memory capable of storing image data for one screen of a color image, and the liquid crystal display panel is driven by the image signal read from the buffer memory. Even if the driving frequency at the time of reading the data does not match the driving frequency of the liquid crystal display panel, good image display can be performed by reading out the image data in the buffer memory while updating it at an appropriate timing.

Further, since a high-resolution color image is displayed on the liquid crystal display panel of the present invention, this display image can be used for printing. In this case, an optical path switching means is provided in the eyepiece optical system, and the optical path is switched between a finder observation position for guiding a display image on the liquid crystal display panel to the eyepiece window and a print position for guiding to a photosensitive recording medium built in the camera body. It is better to do.

[0011]

1 and 2 show the appearance of a front side and a back side of a digital still camera using the present invention. An objective lens 3 is incorporated on the front surface of the camera body 2, and a CCD image sensor is provided on the image forming surface. The CCD image sensor is for obtaining an imaging signal by photoelectrically converting an optical image obtained by the objective lens 3, and may use a MOS image sensor or the like.

On the front surface of the camera body 2, a strobe light emission window 4, projection / reception windows 5 and 6 for distance measurement, and a photometry window 7 for measuring subject brightness are provided. After turning on a power switch (not shown), a release button 8
When the button is pressed halfway, distance measuring light in the near infrared region is projected from the light projecting window 5 toward the subject, and the reflected light is received by a PSD (Position Sensitive Device) provided in the back of the light receiving window 6. The subject distance is measured, and the brightness of the subject is measured by a phototransistor provided behind the photometry window 7. Furthermore, release button 8
When is fully pressed, focusing of the objective lens 3 is performed according to the measured subject distance, and when the subject brightness is equal to or lower than a predetermined level, strobe light is emitted from the strobe light emission window 4 toward the subject.

When the power switch is turned on, the CCD image sensor starts imaging, and the optical image is photoelectrically converted for each pixel to obtain an imaging signal. The subject image is displayed in full color on the liquid crystal display unit 10 built in the camera body 2 based on the imaging signal thus obtained. This display image can be observed as a finder image through an eyepiece window 12 provided on the back of the camera body. The CCD image sensor 10 continues the subject image, so that the finder image is displayed on the liquid crystal display unit 10 in real time.

When the release button 8 is fully depressed, the image pickup signal for one screen obtained from the CCD image sensor 10 at that time is converted into digitized image data, and as shown in FIG. The data is written to a removable memory card 14 loaded from the camera or a flash memory built in the camera body 2. Note that which of the image data recording media is selected can be appropriately set by operating the operation input unit 15, and the setting mode can be confirmed on the display unit 16 configured by a reflective liquid crystal panel.

By operating the operation input unit 15, various other modes can be set. For example, in addition to items related to shooting modes such as forcible ON / OFF switching of flash shooting, selection / cancellation of a self-timer mode, and setting / cancelling of continuous shooting and the number of continuous shooting frames,
In the playback mode, appropriate settings can be made, such as selection of whether the recording medium to be played back is the built-in flash memory or the memory card 14, designation of the frame number of the playback screen, designation / cancellation of continuous playback, and the like. . Of course, these settings can be confirmed on the display unit 16.

In the drawing, reference numeral 18 denotes a protective glass covering the eyepiece window 12, reference numeral 19 denotes a rechargeable / removable battery pack serving as a power source of the digital still camera, and reference numeral 20 denotes an external device. 2 shows a cover for covering various input / output terminal groups for making an electrical connection of FIG.

Unlike the conventional color liquid crystal monitor, the liquid crystal display unit 10 constituting the finder image display means does not include a fluorescent lamp for illuminating the liquid crystal display panel with white light from the back side. As shown in FIG. 3 and FIG. 4, the liquid crystal display unit 10 has a circuit board 23, a diffusion plate 24, a liquid crystal display panel 25, and a transparent protective glass 26 incorporated in a box-shaped housing 22 in this order. Substrate 2
3, a red light emitting diode 28R, a green light emitting diode 28G, and a blue light emitting diode 28B (hereinafter, R-LED, respectively) that emit red, green, and blue as three types of basic color light for obtaining a full-color image. G
-LED, B-LED) are used as light sources for illuminating the liquid crystal display panel 25 from the back side.

The circuit board 23 is electrically connected to the connector 29 through an opening formed behind the housing 22.
A liquid crystal display panel 25 is further connected to the circuit board 23 via a flexible printed board (not shown). Then, in response to the display drive signal supplied from the connector 29, the blinking control of the R-LED, the G-LED, and the B-LED is performed, and the drive control of the liquid crystal display panel 25 is performed.

The liquid crystal display panel 25 has, for example, 4.8 ×
This is a matrix in which 320 × 240 liquid crystal dot segments are two-dimensionally arranged in a matrix in a 3.6 mm rectangular size. Unlike a conventional color liquid crystal monitor, it is not combined with a color microfilter, and is active. High-speed driving is performed for each dot segment by the driving method. For such a liquid crystal display panel 25, for example, "Cyber Display" (trade name) manufactured by Kopin, USA can be used.

The diffusion plate 24 is composed of R-LED, G-LED,
The color light from the B-LED is diffused, so that the back surface of the liquid crystal display panel 25 is uniformly illuminated by each color light. As such a diffusion plate 24, for example, a milky white plastic plate or a transparent plastic plate such as an acrylic resin mixed with a large number of fine beads having a high light diffusion property can be used.

As shown in FIG. 5, the R-LED 28
R, G-LED 28G and B-LED 28B are connected to the circuit board 2
3 and the thick diffusion plate 24 may be integrated with the circuit board 23 so as to surround them. This allows
The liquid crystal display unit 10 can be made thinner as a whole.

When a full-color finder image is displayed on the liquid crystal display unit 10 constructed as described above, as shown in FIG. 6, the liquid crystal display panel 25 and the R-LED, G-LED and B-LED are connected. Driven synchronously. After the imaging signal obtained from the CCD image sensor is separated for each basic color light and converted into digital, image data for each basic color light is obtained, and these image data are sequentially supplied to the liquid crystal display panel 25 for each basic color light. . For red,
When the green and blue image data are sequentially supplied to the liquid crystal display panel 25, all the liquid crystal dot segments constituting the liquid crystal display panel 25 cause the red, green and blue image segments to be displayed.
Each blue frame image is displayed as a grayscale distribution pattern for each dot.

In synchronization with sequentially switching and displaying the frame images for each color on the liquid crystal display panel 25, an LED light emission trigger signal is obtained, and the display period t of each frame image is obtained.
During 1, the corresponding basic color light LED is turned on for a predetermined time. Thus, when a red frame image is displayed on the liquid crystal display panel 25, illumination by the R-LED is performed, and the liquid crystal display unit 10 displays a red image. Similarly, when a green frame image and a blue frame image are displayed on the liquid crystal display panel 25, G
The -LED and the B-LED are turned on, and a green image and a blue image are displayed, respectively.

In this way, a red image, a green image,
The blue images are repeatedly displayed in order. If the switching frequency is sufficiently high, when the switching frequency is observed, the images for each color overlap on the retina due to the afterimage effect and are recognized as a full-color image. Of course, L
The switching of the frame image for each color may be performed in synchronization with the blinking switching signal of the ED.

One full-color image is composed of a set of a red frame image, a green frame image, and a blue frame image.
If the time is set to 16 seconds or less, 16 or more full-color images are displayed per second, and a display without discomfort can be performed. Note that it is simple to set the lighting time of each LED to be shorter than the display period t1 of the frame image, and to determine the timing of turning on / off so as to fall within the display period t1 of the frame image. If the liquid crystal display panel 25 has a fixed light blocking period between the times t1, the lighting of each LED may be switched within this light blocking period.

The brightness of the finder image displayed on the liquid crystal display unit 10 is R-LED, G-LE
In addition to increasing the lighting time of the D and B-LEDs, adjustment can be performed by increasing the drive current of each LED. In addition, since each LED generally has different luminous efficiency (luminance / drive current) for each luminescent color,
Correspondingly, the lighting time and the drive current of each LED can be set to adjust the color balance. In addition,
It is also possible to correct the transmission density of the liquid crystal dot segment according to the luminous efficiency of the LED.

According to the liquid crystal display unit 10, each liquid crystal dot segment constituting the liquid crystal display panel 25 is used as a pixel of a frame image of each color. A full-color image can be displayed with higher definition than a liquid crystal monitor. Further, since a fluorescent lamp which consumes a large amount of power is not used as a light source for illuminating the liquid crystal display panel 25, it is possible to use the built-in battery pack 20 only for a long time.

If the display screen size of the liquid crystal display panel 25 is about 4.8.times.3.6 mm as described above, the image is too small to be observed with the naked eye without any change. For example, FIGS. 7, 8, and 9 An eyepiece optical system having a magnifying action as shown in FIG. FIG. 7 shows a liquid crystal display unit 1
A convex lens 30 for a loupe is provided between 0 and the protective glass 18 fitted in the eyepiece window 12, so that the image displayed on the liquid crystal display panel 25 can be magnified and observed as a virtual image. FIG. 8 shows an example in which a Galilean eyepiece optical system in which a convex lens 31 and a concave lens 32 are combined in order from the liquid crystal display unit 10 side. In this case as well, the image displayed on the liquid crystal display panel 25 is a virtual image. It is observed as magnified.

FIG. 9 shows an example using a Kepler optical system, in which three convex lenses 33, 34 and 35 are combined. The central convex lens 34 is disposed near the image plane of the convex lens 33 and has the function of a field lens.
The aerial image formed near the convex lens by the convex lens 33 is magnified and observed by the convex lens. When such a real image type eyepiece optical system is used, the image displayed on the liquid crystal display unit 10 is observed in a vertically and horizontally inverted image orientation. The finder image is displayed in the upside down and left and right sides. Such a viewfinder image display attitude converting means can be provided to the display controller 48. For example, when displaying a frame image of each color, the image data is converted to a normal image. The liquid crystal display panel 25 may be driven while reading in the reverse order.

FIG. 10 schematically shows the electrical configuration of a digital still camera using the present invention. The system controller 37 is configured by a microcomputer, and controls the overall operation of the digital still camera in accordance with an operation input from the input operation unit 15 or the release button 8. As shown in the main flow of FIG. 11, a mode check is performed after the power switch is turned on, and when the imaging mode is set, imaging is started by the CCD image sensor 40 by driving the CCD driver 39. Various sequence processing programs executed by the system controller 37 are written in the program memory 38.

On the photoelectric surface of the CCD image sensor 40,
Micro color filters of R, G, and B are arranged in a matrix for each pixel, and signal charges are accumulated for each pixel by incident light passing through them. A serial imaging signal is obtained by reading out the signal charge, amplified to an appropriate level by the amplifier 41, and then converted to digital by the A / D converter 42.

The image data obtained by the digital conversion is input to the image signal processing circuit 44. The image signal processing circuit 44 performs well-known signal processing such as matrix operation, white balance adjustment, and gamma correction on the input image data, and further converts the processed image data into an NTSC composite signal. A corresponding image signal is generated, and this is output to the D / A converter 45 and the amplifier 46.
And outputs it to the output terminal 47 for the image signal. Therefore, if a home television monitor is connected to the output terminal 47, a continuous full-color image captured by the CCD image sensor 40 through the objective lens 3 can be observed in real time.

The image signal output from the image signal processing circuit 44 is also input to the display controller 48. The display controller 48 includes a buffer memory 49,
The D / A converter 50, the LCD driver 51, and the LED driver 52 constitute a display driving unit 55 for driving the liquid crystal display unit 10. The display controller 48 receives the image signal from the image signal processing circuit 44, develops the image signal into a frame image for each of red, green, and blue, and writes the image data for each color into the buffer memory 49.

The image data written in the buffer memory 49 is sequentially read out for each color by the display controller 48, and after analog conversion by the D / A converter 50, is supplied to the LCD driver 51 at a period S1. Thus, the red, green, and blue frame images are sequentially displayed on the liquid crystal display panel 25 as shown in FIG. Further, in synchronization with the switching of the frame image display, L
An LED blinking switching signal is input to the ED driver 52, and the R-LED 28R, G-LED 28G, B-LED
28B blinks sequentially to display a finder image.

From the image data written for each color in the buffer memory 49, an image signal for one screen is newly obtained from the CCD image sensor 40, and is input to the image signal processing circuit 44 via the A / D converter 42. It is updated every time. The buffer memory 49 includes a first frame memory 49a and a second frame memory 4 for storing image data corresponding to frame images of three colors, respectively, as shown in FIG.
9b. These frame memories 49a, 49
b: CCD image sensor 40, A / D converter 4
2. Used to display a viewfinder image in real time without a sense of incongruity even if the operating frequency of the imaging system such as the image signal processing circuit 44 does not match the operating frequency for driving the liquid crystal display unit. .

The image data SGNL1 sequentially supplied for each color from the image signal processing circuit 44 is supplied to the first frame memory 49a and the second
The data is written into one of the frame memories 49b according to the write clock pulse CLK1 having the operation frequency of the imaging system. In addition, LC through the D / A converter 50
The image data SGNL2 supplied to the D driver 51 is
The data is read from one of the frame memories 49a and 49b selected by the changeover switch 57 in accordance with the clock pulse CLK2 having the operating frequency for driving the liquid crystal display unit.

The state shown is the first frame memory 49a.
, Image data for one full-color image is read out, and in parallel with this, image data for the next one full-color image is written to the second frame memory 49b. Clock pulse CLK1, C
If the frequency of LK2 matches, the writing of the image data to the second frame memory 49b is completed when the reading of the image data from the first frame memory 49a is completed. In this state, the other frame memories are switched so as to be selected, and reading and writing of image data can be performed continuously.

When the frequency of the write clock pulse CLK1 and the frequency of the read clock pulse CLK2 do not match, the timing of switching the changeover switches 56 and 57 is controlled, or
By retracting to a neutral position that is not connected to either of the second frame memories 49a, 49b, adjustment can be made.

For example, when the frequency of the write clock pulse CLK1 is high, the writing of the image data to the second frame memory 49b is completed while the image data is being read from the first frame memory 49a in the illustrated state. Therefore, in this case, when the writing of the image data to the second frame memory 49b is completed, the changeover switch 56 is retracted to the neutral position, and the process waits until the reading of the image data from the first frame memory 49a is completed.

When the reading of the image data from the first frame memory 49a is completed, the changeover switch 57 is connected to the second frame memory 49b to read out the image data of the next display image, and the changeover switch 56 From the neutral position to the first frame memory 49a.
And the next new image data may be written.

On the contrary, when the frequency of the read clock pulse CLK2 is high, in the state shown in the figure, the changeover switch 57 is kept as it is until the image data is completely written into the second frame memory 49b, and the image is continuously transferred from the first frame memory 49a. The data is continuously read, and an image is displayed. Then, the second frame memory 49
When the writing of the image data to b is completed, the changeover switches 56 and 57 are simultaneously connected to the other frame memory side to read out new image data from the second frame memory 49b, and to read the first frame memory. It is sufficient to write new image data in 49a.

The system controller 37 further performs EE
Data is transferred between the PROM 59, the frame memory 60, and the decoration data memory 61. Various correction data and control data are written in the EEPROM 59, and are read out at an appropriate timing when the digital still camera is operated according to a prescribed sequence program. The frame memory 60 is composed of a DRAM (Dynamic Random Access Memory) that can be accessed at a high speed, and the image data obtained from the image signal processing circuit 44 when the image is taken by operating the release button 8 is displayed for each screen. It has a storage capacity for storing, for example, image data for 50 screens.

In the decoration data memory 61, decoration data for changing the shape or pattern of the screen frame surrounding the subject image into various forms is written in advance. Note that data such as characters, marks, characters, and messages may be prepared in the decoration data memory 61 so that these can be combined with a part of the subject image. These data can be read out in the reproduction mode, and are displayed on the liquid crystal display unit 10 together with the subject image.

The system controller 37 monitors an operation input from the input operation unit 15 via the I / O port 62,
The operation of the AF device 63 and the flash device 64 is controlled. Further, the memory card 1 connected via the connector 65
4. Access the data input / output terminal group 66 to exchange image data.

Next, the operation of the digital still camera will be described with reference to the flowchart of FIG. After the power switch is turned on, a mode check is performed, and the operation branches to one of an imaging mode and a reproduction mode according to an operation input from the input operation unit 15. Under imaging mode, CCD
A subject image is continuously captured by the image sensor 40, and the captured signal is input to an image signal processing circuit 44 as digitized image data via an amplifier 41 and an A / D converter 42.

After the signal processing by the image signal processing circuit 44, the image data is written into the buffer memory 49 by the display controller 48. The image data of one full-color image written in the buffer memory 49 is read out in units of red, green, and blue frame images as shown in FIG. It is input to the driver 51.

In synchronization with this, the display control controller 48 inputs an LED blinking switching signal to the LED driver 52, and the R-LED 28R, the G-LED 28G, and the BL
The ED 28B repeats blinking sequentially. As a result, a full-color image is displayed on the liquid crystal display unit 10 in a color-sequential manner.
The viewfinder image magnified by 0 can be observed.

When the release button 8 is half-pressed, the AF device 61 operates to measure the subject distance, and the luminance of the subject is measured through the photometry window 7. Subsequently, when the release button 8 is fully pressed, the objective lens 3 is focused according to the measured subject distance, and then a still image is captured. When the luminance of the subject is lower than the specified level, the strobe device 64 is operated and the strobe light is emitted from the strobe light emission window 4 toward the subject.

Immediately after the release button 8 is fully pressed, the
An image signal for one screen obtained from the D image sensor 40 is similarly converted into image data, and then input to the image signal processing circuit 44. After signal processing by the image signal processing circuit 44, the image data for one full-color image is transferred to the frame memory 60 via the system controller 37 and written therein. Since the frame memory 60 has a memory capacity for 50 full-color images, image data of 50 still images can be stored in the same manner. When the memory card 14 is selected as a recording destination of image data by the input operation unit 15, the I / O port 62 and the connector 65
The image data is recorded on the memory card 14 via the.

Even after 50 frames of image data have been written into the frame memory 60, the image data of a new image can be stored by deleting the image data of an appropriate frame. These processes can be performed by key input from the input operation unit 15, and the data input / output terminal group 6
If another storage medium is connected to 6, an external storage medium can store image data obtained by new imaging, or transfer and store image data of an appropriate frame read from the frame memory 60. It becomes possible.

In the reproduction mode, when image data of an arbitrary frame is selected from the frame memory 60 by a key input from the input operation unit 15, the image data is passed through the image signal processing circuit 44 to the display controller 48. And stored in the buffer memory 49. Therefore,
By repeatedly reading the image data written in the buffer memory 49, the liquid crystal display unit 1
At 0, a full-color still image based on the image data can be continuously displayed.

When a decoration frame selection operation is performed by key input from the input operation unit 15,
In addition to the image data read from the flash memory 60, the decorative frame data read from the decorative data memory 61 is also transferred to the image signal processing circuit 44, and the decorative frame is displayed on the liquid crystal display unit 10 together with the reproduced still image. Will also be synthesized and displayed.

The still image reproduced on the liquid crystal display unit 10 in this manner is further input to the input operation unit 1.
By operating the terminal 5, the image data can be output from the data input / output terminal group 66. Therefore, if an appropriate video printer is connected to the data input / output terminal group 66, a hard copy thereof can be obtained. Of course, by connecting a personal computer to the data input terminal group 66, image data can be exchanged between the digital still camera and the personal computer. In this case, the data input / output terminal group 66 Inside the connector for ISDN line and IR
It is convenient to provide a port for infrared communication such as DA and to prepare each communication program in the program memory 38.

Further, the liquid crystal display unit 1
0 can also be used as an exposure device for a printer.
13 and 14 show the appearance of the front side and the back side of a digital still camera having a printer function, and FIG. 15 shows a cross section of a main part thereof. This embodiment will be described below. Note that members and functional components common to the above-described embodiments are denoted by common reference numerals.

On the upper surface of the camera body 2, in addition to the release button 8 and the input operation unit 15, an outlet 70 for an instant film unit is provided.
Then, as shown in FIG. 14, the instant film unit 71 which has completed the printing process is discharged. As shown in FIG. 15, about ten instant films 71 are stored in a film pack 72 in a stacked state, and are packed on the back of the camera body 2 for loading a new film pack 72 and removing the empty film pack 72. Loading lid 7
3 is attached so that opening and closing are possible.

A pack pressing spring 74 is provided on the inner wall of the pack loading lid 73, and presses the film pack 72 to a predetermined position in the pack loading chamber for positioning. A film pressing plate 75 urged forward by a spring is further provided on the inner wall of the pack loading lid 73. The film pressing plate 75 penetrates through the opening formed in the rear wall of the film pack 72 to enter the inside of the pack. The unit 71 is pressed against the inner front wall of the film pack 72. Thus, the uppermost instant film unit 71 is positioned at the exposure position regulated by the front wall of the pack.

A movable mirror 77 for switching the optical path is provided behind the convex lens 30 constituting the eyepiece optical system, and rotates between a finder observation position shown by a solid line in FIG. 15 and a print position shown by a two-dot chain line. It is free to move. When the movable mirror 77 is at the finder observation position, the image displayed on the liquid crystal display unit 10 is enlarged and observed from the eyepiece window 12 through the convex lens 30 as in the previous embodiment. When the mirror switching solenoid 78 is turned on, the movable mirror 77 moves to the print position, and the image displayed on the liquid crystal display unit 10 includes the convex lens 30, the movable mirror 77, the print lens 79, and the mirror 8.
The image is magnified and formed on the instant film unit 71 by the print optical system composed of zero.

As disclosed in a known instant camera or JP-A-7-248533, an exposed instant film unit 7 is connected to a film pack 72.
In order to develop the developing solution while discharging the developing solution, the digital still camera incorporates a developing mechanism including a developing motor, a scraping claw, and a pair of developing rollers 82. When the unfolding motor is started, the scraping claw is engaged with the lower end of the uppermost film unit 71 in the film pack 72, and the instant film unit 71 is lifted upward as the scraping claw moves.

Slits are formed in the film pack 72 and the upper wall of the pack loading chamber, and the upper end of the instant film unit 71 lifted by the scraping claw enters between the pair of developing rollers 82 already rotating. Thereafter, the instant film unit 71 is sent out by the developing roller 82, and at this time, the developing solution pod 71a built in the instant film unit 71 is crushed by the developing roller 82, and the photosensitive sheet on the exposure surface side of the instant film unit 71 and the back The developing solution is spread with a uniform thickness between the surface and the image receiving sheet.

The instant film unit 71 on which the developing solution has been spread in this way is discharged out of the camera body 2 through the discharge port 70. After one to several minutes of development and fixing time, the latent image formed by exposing the photosensitive sheet is transferred and developed on the image receiving sheet, and the printed image can be observed from the back surface side. Since the instant film unit 71 has a fixed size and the amount of rotation of the developing motor required for one developing process is constant, the developing motor stops automatically when the developing mechanism completes one cycle of operation. It is supposed to.

The digital still camera having a printer function is provided with an electric motor 85 and a mirror switching solenoid 78 as electrical components as shown in FIG. 16, and the program memory 38 executes the processing shown in FIG. A sequence program to make it work has been added. The developing motor 85 is activated upon receiving a command from the system controller 37, drives the developing mechanism, and sends out the exposed instant film unit 71 from the discharge port 70. The mirror switching solenoid 78 switches the movable mirror 77 between the finder observation position and the print position as described above.

This digital still camera has an "imaging mode" and a "reproduction mode" shown in the flowchart of FIG.
In addition to the above, a “print mode” is added to the main menu, and the print sequence shown in FIG. When the print mode is selected, the apparatus enters a standby state for inputting selection of a frame to be printed. Selection of a frame to be printed starts with selection of a recording medium.
4, the frame memory 60, or any of the external devices connected to the data input / output terminal group 66
Is selected according to the key operation of.

When the frame number is selected and input after the selection of the recording medium, the image data of the frame number is read out by the system controller 37 and the image signal processing circuit 44
Are written into the buffer memory 49 by the display controller 48 after the signal processing. The image data written in the buffer memory 49 is read by the display controller 48 in the same manner as in the reproduction mode, and is displayed on the liquid crystal display unit 10 as a full color image. At this time, if there is a selection input of the decoration frame,
The decorative frame is also displayed on the liquid crystal display unit 10 together. The processing up to this point is completely the same as the playback mode shown in FIG.
It may be possible to shift to the print mode following the reproduction mode in.

After confirming the image of the frame to be printed through the eyepiece window 12, if printing is necessary, a print start input is made from the operation input unit 15. When a print start input is detected by the system controller 37, all of the R-LED, G-LED, and B-LED are turned off once, and the image display on the liquid crystal display unit 10 is interrupted. Subsequently, the mirror switching solenoid 78 is turned on, and the movable mirror 77 rotates from the finder observation position to the print position. When it is confirmed by a photo sensor or a micro switch that the movable mirror 77 has been switched to the print position, the display controller 4
The print processing is performed by 8.

In the printing process, an appropriate exposure amount is obtained in consideration of the ISO sensitivity of the instant film unit 71 and the F value of the printing optical system including the convex lens 30, the movable mirror 77, the print lens 79, and the mirror 80. This is performed by controlling the lighting time of the R-LED, G-LED, and B-LED as described above.

In controlling the lighting of each LED in the printing process, the red, green, and blue frame images are sequentially displayed during the display period t1 as shown in FIG.
, R-LED, G-LED, B
When the LED is turned on, the number of repetitions of the basic cycle S1 may be determined according to the appropriate exposure amount. Further, the R-LED is continuously turned on while displaying the red frame image until the proper exposure amount of red is reached, and then the G-LED and the B-LE are displayed while sequentially displaying the green and blue frame images.
D may be lit continuously for a required time.

The print image displayed on the liquid crystal display unit 10 is enlarged and imaged on the instant film unit 71.
Are used as one pixel for each of the basic color lights, so that a sufficiently high-definition print image can be obtained even on the instant film unit 71.

The print image displayed on the liquid crystal display unit 10 includes the movable mirror 77 and the mirror 8.
0 is reflected twice to form an image on the instant film unit 71, and the print image obtained on the instant film unit 71 is observed from the base surface side.
, The print image may be displayed in a normal posture.
Further, it is preferable to close the eyepiece shutter in conjunction with the switching of the movable mirror 77 so that external light does not enter the print optical path from the eyepiece window 12 during printing.

When the exposure by the liquid crystal display 10 is completed, the driving of the developing motor 85 is started, the exposed instant film unit 71 is lifted upward by the scraping claw, and the upper end thereof is fed between the developing rollers 82. Since the developing roller 82 rotates in the feeding direction together with the driving of the developing motor 85, when the upper end of the instant film unit 71 is fed therebetween, it is sent to the discharge port 70.

When passing between the developing rollers 82, the developing solution pod 71a is crushed, and the developing solution sealed therein is developed uniformly between the photosensitive sheet and the image receiving sheet. When the developing motor 85 reaches a predetermined rotation amount, the instant film unit 71
At this point, the driving of the developing motor 82 is stopped, and one cycle of the developing process is completed. The latent image formed on the photosensitive sheet is transferred to the image receiving sheet by the developed developing solution, and after a predetermined time required for the developing and fixing processes has elapsed, the printed image is observed from the base surface side of the instant film unit 71. Will be able to do it.

When the developing process is completed, the mirror switching solenoid 78 is turned off, and the movable mirror 77 returns from the print position to the finder observation position. When the movable mirror 77 returns to the finder observation position, the display controller 48 reads out image data from the buffer memory 49 as in the reproduction mode, and the print image is displayed on the liquid crystal display unit 10 again. Here, when the print start input is performed again, the second print of the image of the same frame can be performed. Of course, when the frame to be printed is selected again, the print can be obtained in the same procedure.

In the embodiment shown in FIG.
The finder optical path and the print optical path are switched by rotating the movable mirror 90 behind. In the print mode, the image displayed on the liquid crystal display unit 10 includes the convex lens 30 and the movable mirror 9.
0, the image is enlarged and formed on the instant film unit 71 via the print lens 79. In this embodiment, unlike the previous embodiment, only one reflection is performed in the print optical path.

Accordingly, the image is displayed on the liquid crystal display unit 10 in a normal posture so that the printed image can be observed in advance through the eyepiece window 12.
When printing is performed by simply moving the movable mirror 90 to the printing position during printing, if the image is observed from the base surface side of the instant film unit 71, the printed image is in an inverted posture only in the left and right directions. Occurs. In order to avoid this, when the movable mirror 90 is in the finder observation position, an image is displayed on the liquid crystal display unit 10 in a normal posture, and after the movable mirror 90 is switched to the print position by a print start input, The print processing may be performed by displaying an image in which only the left and right directions are reversed on the liquid crystal display unit 10.

As described above, when there is a difference between the number of reflections in the finder optical path and the number of reflections in the print optical path, the posture of the image displayed on the liquid crystal display unit 10 is changed to that for the finder observation. It becomes necessary to switch between printing and printing. Such a posture changing means of the display image can be simply configured by hardware including the system controller 37, the display controller 48, and the buffer memory 49, and software stored in the program memory 38. For example, in the above embodiment, when the movable mirror 90 is at the finder observation position, the system controller 37 controls the display controller 48 so as to display images while reading image data from the buffer memory 49 in a normal order. After the movable mirror 90 is switched to the print position, the display controller 48 may be controlled so that the order in which the image data is read from the buffer memory 49 is reversed only in the horizontal direction of the screen.

The eyepiece window 12 is provided on the upper surface of the camera body 2 and a fixed mirror is further provided behind the movable mirror 90 so that a single reflection is always performed in the finder optical path. The unit 10 can also respond by displaying an image in which the posture is reversed only up and down with respect to the normal posture. As the instant film unit, unlike the transmission observation type instant film unit 71 described above, a reflection observation type in which the finally obtained image is observed from the exposure surface side is also commercially available. When such a reflection observation type is used, in the embodiment of FIG. 18, an image in a normal posture may be always displayed on the liquid crystal display unit 10. Of course, in the case of the embodiment shown in FIG. 15, when printing is performed, it is necessary to switch the image displayed on the liquid crystal display unit 10 to the reverse posture only in the horizontal direction.

Although the present invention has been described with reference to the illustrated embodiments, the present invention is not limited to these embodiments. For example, when displaying images on the liquid crystal display unit 10, the display order of the frame images of each color and the lighting order of the LEDs are red, green,
The order is not limited to blue and can be changed as appropriate. In addition, if the switching period is such that the frame image of each color can be recognized as a full-color image due to the afterimage effect on the retina, the display period of the frame image of each color and the lighting period t1 of the corresponding LED are not necessarily uniform. Good. Furthermore, three types of basic color light for full-color image display may be used, or a combination of, for example, cyan, magenta, and yellow may be used if appropriate light sources are used.

The present invention is applicable not only to the above-described digital still camera, but also to a digital video camera for moving images for recording image data in a digital format on an external medium such as a video tape or a CD-ROM, as well as an image signal in an analog format. It is equally applicable to still or movie video cameras that record on magnetic sheets or video tapes, and can also be applied to hybrid video still cameras that combine the functions of general photo cameras. it can. In a video camera in which the liquid crystal display unit 10 can also be used for printing, not only an instant film unit but also a general silver salt photosensitive medium such as a photographic film or a photographic film sheet is used as a recording medium for the printing. Various photosensitive materials can be used as well as the materials.

[0078]

As described above, according to the video camera of the present invention, the frame images of the basic color light are sequentially displayed on the liquid crystal display panel, and the illumination is given by the corresponding basic color light in synchronization with the display. Since a color image is displayed in a sequential manner, and a finder image display unit that enables a full-color image to be observed by an afterimage effect is used, the liquid crystal display panel is reduced in size, and the display image is enlarged and observed with an eyepiece optical system. Also, a fine finder image can be obtained. Accordingly, it is possible to reduce the size of the viewfinder image display means using liquid crystal itself, and it becomes possible to display a clear image only by using LEDs with low power consumption as a light source. This eliminates the need for expensive fluorescent lamps, and is extremely advantageous in preventing power consumption.
Further, since a high-definition image can be displayed by the finder image display means, the finder image display means can be used for printing only by providing an optical path switching means such as a movable mirror in the eyepiece optical system. Is also possible.

[Brief description of the drawings]

FIG. 1 is a front external view of a still video camera using the present invention.

FIG. 2 is a rear side external view of the still video camera shown in FIG.

FIG. 3 is an exploded perspective view of the liquid crystal display unit.

FIG. 4 is a sectional view of a main part of the liquid crystal display unit shown in FIG.

FIG. 5 is an exploded perspective view showing another example of the liquid crystal display unit.

FIG. 6 is a time chart illustrating an operation of the liquid crystal display unit.

FIG. 7 is a schematic diagram illustrating an example of an eyepiece optical system.

FIG. 8 is a schematic diagram showing another example of the eyepiece optical system.

FIG. 9 is a schematic diagram showing still another example of the eyepiece optical system.

FIG. 10 is a block diagram showing an electrical configuration of the still video camera shown in FIG.

11 is a flowchart showing the operation of the still video camera shown in FIG.

FIG. 12 is an explanatory diagram showing a configuration example of a buffer memory and its operation.

FIG. 13 is a front side external view showing another embodiment of the present invention.

FIG. 14 is a rear external view of the still video camera shown in FIG.

FIG. 15 is a sectional view of a main part of the still video camera shown in FIG.

FIG. 16 is a block diagram showing an electrical configuration of the still video camera shown in FIG.

FIG. 17 is a flowchart showing an outline of print processing of the still video camera shown in FIG.

FIG. 18 is a cross-sectional view of a main part showing still another embodiment of the present invention.

[Explanation of symbols]

 2 Camera Body 3 Objective Lens 10 Liquid Crystal Display Unit 12 Eyepiece Window 14 Memory Card 23 Circuit Board 24 Diffusion Plate 25 Liquid Crystal Display Panel 28R R-LED 28G G-LED 28B B-LED 71 Instant Film Unit 72 Film Pack 77 Movable Mirror 79 Print Lens 80 mirror 82 developing roller 90 movable mirror

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H04N 9/04 H04N 9/04 B 9/30 9/30 (72) Inventor Hiroshi Omura 3-13-45 Izumi, Asaka-shi, Saitama Irum Corporation

Claims (4)

[Claims] 1. An image pickup means for photoelectrically converting an optical image formed by an objective lens to obtain an image signal, and the optical image is formed based on image signals for three types of basic color light obtained from the image signal. In a video camera including a finder image display unit for reproducing and displaying, and a built-in or detachable recording medium on which an image signal for at least one color image is recorded, the finder image display unit is a transmission type. A liquid crystal display panel in which liquid crystal dot segments are two-dimensionally arranged, a light source for sequentially irradiating the three types of basic color light from behind the liquid crystal display panel, and an image signal for each basic color light is sequentially repeated on the liquid crystal display panel. It supplies and changes the transmission density of the liquid crystal dot segment for each basic color light, and in synchronization with this, the three kinds of basic color lights blink repeatedly and sequentially. And a display driving means for driving the light source, and an eyepiece optical system for enlarging and observing an image displayed on the liquid crystal display panel through an eyepiece window. . 2. A light source comprising a red light emitting diode, a green light emitting diode, and a blue light emitting diode, a cycle for sequentially and repeatedly supplying an image signal for each basic color light to a liquid crystal display panel, and a cycle for switching the lighting of each light emitting diode. Is 1/16 second or less.
The described video camera. 3. The display driving means includes a buffer memory for storing image data obtained by digitally converting an image signal for one screen of a color image, and based on image data read out for each basic color light from the buffer memory. 3. The video camera according to claim 1, wherein the liquid crystal display panel is driven. 4. An eyepiece optical system comprising: a viewfinder observation position for guiding an image displayed on a liquid crystal display panel to an eyepiece window;
Including optical path switching means switched between a print position leading to a photosensitive recording medium built into the camera body,
4. The video camera according to claim 3, wherein the image displayed on the liquid crystal display panel is printed on the photosensitive recording medium by switching the optical path switching means to a print position.