JP2001042208A - Image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain an exact focusing position by providing plural beam light emitting means set so that the beams of light may be crossed each other at a specified distance position and a light emission control means controlling light emitting timing. SOLUTION: In the case of setting a macro mode, an LED driving part drives two LEDs (red) 30 and (green) 31 to emit light in proper timing under control of a CPU. The LEDs 30 and 31 are dividedly arranged on right and left sides of a lens 11 and fixed so that the beams of light by light emission may be crossed each other at a macro photographing distance peculiar to the lens 11, for example, at the position of 10 cm exactly from the top of the lens 11. For example, the LED 30 positioned on the right side of the lens 11 emits the red beam of light and the other LED 32 emits the green beam of light. When a subject 32 is accurately positioned at the macro photographing distance, two beams of light are radiated to be superposed at one spot of the subject 32, so that the beam spot of yellow being additive color of red and green is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus suitable for a digital camera having a macro function.

[0002]

2. Description of the Related Art Recently, in addition to a camera using a silver halide film, a digital camera that records image data obtained by photographing with an image pickup device such as a CCD on a recording medium such as a memory card has been widely and widely used. I have.

[0003] Some digital cameras of this type have a macro (close-up) function. This macro function
Macro shooting distance unique to the lens, for example, 1
By taking a picture with the camera positioned so that the subject is at a distance of 0 cm, for example, taking an image of a business card so that it covers the entire screen, or placing a relatively small subject such as a flower or insect before and after it This is used when taking close-up shots of a certain object with a lot of blur.

[0004]

However, in the above-mentioned macro function, the depth of field (the range in which focus is achieved) is extremely narrow, and even if the subject is slightly out of the macro shooting distance, the image is blurred. Therefore, at the time of photographing, the distance between the lens and the subject must be accurately matched using, for example, a ruler according to the macro photographing distance unique to the lens, and a very complicated operation is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to easily obtain an accurate focus position and to easily utilize a macro function. To provide a simple imaging device.

[0006]

According to the first aspect of the present invention,
It is characterized by comprising a plurality of beam light emitting means provided so that the light beams intersect at a specific distance position in the photographing area, and light emitting control means for controlling light emission timing of the light beam by the beam light emitting means. And

With such a configuration, if the beam emitting means is provided in advance so as to intersect at the macro shooting distance of the lens, accurate focusing can be achieved by matching / mismatching a plurality of light beams irradiated on the subject. The state can be easily checked, and the emission of the light beam is stopped during shooting, so that the light beam does not appear in the shot image.

According to a second aspect of the present invention, in the first aspect of the present invention, the plurality of beam emitting units emit light beams of different colors.

With such a configuration, in addition to the operation of the first aspect of the present invention, when a plurality of light beams do not coincide with each other on the subject, the direction of the original color is determined based on the positional relationship of the colors. Since it is possible to easily determine whether the in-focus position is shifted, the alignment becomes easier.

According to a third aspect of the present invention, in the first aspect of the present invention, a display means for displaying an image of the photographing area on a monitor is further provided.

According to this structure, in addition to the effect of the first aspect of the present invention, the light beam irradiated on the subject can be confirmed on the monitor display screen for photographing, instead of being directly viewed. This makes macro shooting easier.

According to a fourth aspect of the present invention, in the second aspect of the present invention, there is provided a calculating means for calculating a distance between respective spot center positions of a plurality of light beams irradiated on a subject by the plurality of light emitting means. A focus control unit that variably sets a focus position of the photographing lens based on a result obtained by the calculation unit and a positional relationship between colors of the plurality of light beams emitted to the subject. .

With this configuration, in addition to the operation of the second aspect of the present invention, the size of the subject in the image can be arbitrarily changed within the focusing range of the photographing lens. A composition can be selected, and an operation for obtaining accurate focusing is not required, so that macro photography can be more easily utilized.

According to a fifth aspect of the present invention, in the second aspect of the present invention, there is provided a calculating means for calculating a distance between respective spot center positions of a plurality of light beams irradiated on a subject by the plurality of light emitting means. And an instructing means for instructing a photographing position based on a result obtained by the calculating means and a positional relationship between the colors of the plurality of light beams emitted to the subject.

With such a configuration, in addition to the operation of the second aspect of the present invention, accurate alignment can be performed only by changing the position of the imaging device as instructed by the instructing means.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment in which the present invention is applied to a digital camera having a fixed macro shooting distance will be described below with reference to the drawings.

FIG. 1 shows the circuit configuration, and reference numeral 10 denotes a digital camera. The digital camera 10 can set a recording mode and a reproduction mode. In the recording mode, the CCD 12 serving as an image pickup device, which is disposed behind the lens 11, operates as a timing generator (T).
G) Scanning is performed by the vertical driver 13, and the photoelectric conversion output for one screen is output at regular intervals.

The photoelectric conversion output is sampled and held by a sample / hold circuit (S / H) 15, converted into digital data by an A / D converter (A / D) 16, and subjected to color processing by a color processing circuit 17. Done
The luminance and color difference multiplex signal (YUV data) of the digital value is stored in a DMA (Direct Memory Acc).
ess) Output to the controller 18.

The DMA controller 18 once writes the YUV data output of the color process circuit 17 into a buffer inside the DMA controller 18 using the synchronization signal, memory write enable, and clock output of the color process circuit 17 as well, and the DRAM interface (I / F) 1
9 to the DRAM 20 via the DMA transfer.

The CPU 21 performs DRA of the YUV data.
After the DMA transfer to M20 is completed, this YUV data is
The data is read from the DRAM 20 via the RAM interface 19 and the VRAM 23 is read via the VRAM controller 22.
Write to.

A digital video encoder (hereinafter abbreviated as "video encoder") 24 periodically reads out the YUV data from the VRAM 23 via the VRAM controller 22, generates a video signal based on these data, and displays the video signal. 25.

The display section 25 is composed of, for example, a color liquid crystal display panel with a backlight and its driving circuit.
Located on the back side of the camera, EVF in recording mode
(Electronic View Finder), which displays an image based on the image information captured from the CCD 12 at that time by performing display based on the video signal from the video encoder 24. Become.

When the shutter key constituting the key input section 26 is operated at a timing at which recording and preservation is to be performed in a state where the current image is displayed on the display section 25 in real time, a trigger signal is generated. appear.
In response to the trigger signal, the CPU 21
DR of one screen of YUV data taken from D12
Immediately after the end of the DMA transfer to the AM 20, the path from the CCD 12 to the DRAM 20 is stopped, and the state transits to the state of recording and saving.

In this recording and storage state, the CPU 21
The YUV data for one frame written in the RAM 20 is transferred to the Y, Cb, C
Each component of r is read out in a unit called a basic block of 8 × 8 pixels and written to the JPEG circuit 27, and the ADCT (Adaptive) is performed by the JPEG circuit 27.
e Discrete Cosine Transfo
rm: adaptive discrete cosine transform), code data compressed by Huffman coding or the like, which is an entropy coding method, is read from the JPEG circuit 27 and written into a flash memory 28 which is a nonvolatile memory.

When the compression process of one frame of YUV data and the writing of all the compressed data to the flash memory 28 are completed, the CPU 21 activates the path from the CCD 12 to the DRAM 20 again.

The key input unit 26 has a recording (REC) mode and a reproduction (PL) mode in addition to the shutter key.
A / Y mode switching key, a macro shooting key for performing macro shooting in the recording mode, an image selection key, etc., and a signal accompanying the key operation is directly sent to the CPU 21.

The shutter key performs a two-stage pressing operation. In general photographing, AF (autofocus), AE (automatic exposure),
In addition, the execution values of AWB (automatic white balance) are locked to prepare for photographing, and in the second-step full-press state, the above-described trigger signal is output and the photographing operation is switched as needed. (In the macro photography mode, the execution values are not locked in the half-pressed state.) When the macro mode is set, the LED driving unit 29 controls the two LEDs 30 and 31 appropriately under the control of the CPU 21. Light emission driving is performed at the timing.

The LEDs 30 and 31 are arranged separately on the left and right sides of the lens 11, and as shown in FIG. 2, a macroscopic photographing distance unique to the lens 11, for example, a light beam emitted by light emission at a position exactly 10 cm from the tip of the lens. It is fixed using a lens member of an optical system (not shown) so as to intersect, for example, the right side of the lens 11 (the left side of the lens 11 when the digital camera 10 is viewed from the front). LED 30 emits a red light beam, and an LED 31 located on the left side of the other lens 11 (the right side of the lens 11 when the digital camera 10 is viewed from the front) emits a green light beam, When the subject 32 is accurately positioned at the macro shooting distance, two light beams are irradiated so as to be superimposed on one point of the subject 32 as illustrated. Because, so that the red and green yellow beam spot is an additive color is formed.

When the distance between the subject 32 and the lens 11 is calculated from the light beams of the LEDs 30 and 31, the CP
Under the control of U21, the lens driving unit 33 variably sets the focus position of the lens 11 according to the calculated distance between the lens 11 and the subject 32, and drives the lens.

In the reproduction mode, the CPU 21
The path from D12 to the DRAM 20 is stopped, and in response to an operation of an image selection key or the like of the key input unit 26, the CPU 21 reads out a specific one frame of code data from the flash memory 28 and writes it into the JPEG circuit 27, and the JPEG circuit 2
The YUV data for one frame is developed and stored in the VRAM 23 via the VRAM controller 22 in units of 8 × 8 pixels basic blocks obtained by performing the careful processing in step 7. Then, the video encoder 24 converts the VRAM
A video signal is generated based on one frame of YUV data expanded and stored in the storage unit 23 and displayed on the display unit 25.

Next, the operation in the recording mode according to the present embodiment, particularly when performing macro shooting, will be described.

FIG. 3 shows an operation procedure at that time. Steps indicated by solid lines in the figure are operations performed by the user using the digital camera 10, and steps indicated by broken lines are steps performed by the digital camera 10. Mainly CPU21
Is an operation automatically executed by

At the beginning of the operation, the recording /
The recording mode is set with the re-mode switching key, and the macro shooting key is operated to specify macro shooting (step A01).

By operating the macro photographing key, the AF (auto focus) function of the digital camera 10 is released, and the macro photographing distance unique to the lens 11 preset in the digital camera 10, for example, 10 cm from the tip of the lens 11 The focus position is fixed at the position.

Next, when the shutter key of the key input section 26 is half-pressed (step A02), the LEDs 30 and 31 are simultaneously turned on by the LED driving section 29,
The red and green light beams are emitted toward the subject (step A03).

The user looks at the display unit 25 in this state,
Whether the irradiation positions of the red and green light beams on the subject 32 are coincident, that is, both light beams
It is determined whether the correct macro shooting distance is maintained based on whether a yellow beam spot intersects at one point on 2 (step A04).

Here, the irradiation positions of the two light beams do not match, and the two light beams of red and green are separated and the object 3
In the case where the light is projected onto the object 2, the user then determines whether the correct focus position is on the front side of the subject 32 depending on whether the right one of the two light beams is red.
It is determined whether or not a so-called “front pin” state is established (step A05).

Here, as shown in FIG.
When the distance between 1 and the subject 32 exceeds 10 cm, a so-called “back focus” state is established, and after the two light beams cross each other, the positional relationship is reversed, and the two light beams are irradiated onto the subject 32, Since the right side is green instead of red, the digital camera 10 is gradually brought closer to the subject 32 (step A07), and the process returns to step A04 again.

Further, as shown in FIG. 4 (2), in the step A05, the 2
When it is determined that the right one of the two light beams is red, the distance between the lens 11 and the subject 32 is less than 10 cm, and the two light beams fall on the subject 32 before intersecting. , The digital camera 10 is gradually moved away from the subject 32 (step A0).
6) Return to step A04 again.

Then, the digital camera 10 and the subject 3 are processed by the processing in step A07 or step A06.
By adjusting the distance between the two light beams, the spots of the two light beams on the subject 32 displayed on the display unit 25 gradually approach, and the distance between the tip of the lens 11 and the subject 32 becomes exactly one.
At the time when the distance reaches 0 cm, as shown in FIG. 4C, when the irradiation positions of the two light beams on the subject 32 match, and a single yellow beam spot is obtained, the correct macro shooting distance is maintained. Therefore, this is determined in step A04, the position of the digital camera 10 at that time is determined as a correct photographing position (step A08), and the shutter key is fully pressed as it is (step A09).

In response to the full-press operation of the shutter key,
The CPU 21 that has received the trigger signal stops the light emission operation of the LEDs 30 and 31 by the LED drive unit 29 (step A10) in order to prevent the light beam from being reflected in an image to be captured (step A10). An imaging operation is performed with the focus position fixed at the shooting distance (step A11).

As described above, it is possible to easily confirm an accurate in-focus state by matching / mismatching a plurality of light beams irradiated on the subject 32, and by stopping emission of the light beams during photographing, The light beam does not appear in an image to be shot.

At this time, since the colors of the two light beams are different from each other, it is possible to easily determine in which direction the original in-focus position is shifted from the positional relationship between the colors, and the alignment is easier. Becomes

Further, since the light beam irradiated onto the subject 32 can be confirmed on the monitor screen of the display unit 25 used as an EVF, instead of being directly viewed, the digital camera 10 can be held. Macro photography can be easily performed in an extremely natural posture without being forced to take an unnatural photographing posture such as looking into the subject 32 from the side.

Although this point is an advantage unique to a digital camera having an EVF, a single-lens reflex type digital camera can perform the same check with an optical viewfinder without using an EVF. This is useful when battery consumption due to use is desired to be avoided. Further, the present invention is not limited to a digital camera, but is also applicable to a single-lens reflex type or range finder type silver halide camera.

(Second Embodiment) A second embodiment in which the present invention is applied to a digital camera capable of variably setting a macro shooting distance within a predetermined range will be described with reference to the drawings.

The circuit configuration of the digital camera is basically the same as that shown in FIG.
The same portions are denoted by the same reference numerals and description thereof will be omitted.

As described above, the macro photographing distance can be variably set within a predetermined range.
Numeral 31 is fixed using a lens member or the like of an optical system (not shown) so that light beams emitted by light emission intersect at a fixed macro shooting distance, for example, exactly 10 cm from the front end of the lens as shown in FIG. Shall be.

However, in the present embodiment, the LED 30 that emits red light and the LED 31 that emits green light are not simultaneously driven for lighting, but only one of them is sequentially switched to be driven for lighting.

Next, the operation in the recording mode according to the present embodiment, particularly when performing macro photography, will be described.

FIG. 5 shows an operation procedure at that time, which is mainly executed by the CPU 21.

At the beginning of the operation, it is confirmed whether or not the macro photographing mode is set by operating the macro photographing key (step B01). Execute the process.

After confirming that the macro photographing mode is set, the CPU then waits for the shutter key to be half-pressed (step B02). Only the LED 30 located on the right side of the LED is driven to light up, and the subject 32 is irradiated with a red light beam (step B03).

Then, the center position of the red beam spot in the image data obtained in this state is calculated for each pixel (step B04), and then the light emission of the LED 30 is released (step B05).

The calculation of the center position of the beam spot is as follows.
Only the R signal is obtained by a general conversion operation for converting a YUV signal into an RGB signal, and a portion of a substantially circular pattern in which the R component data is equal to or larger than a predetermined threshold is obtained in the image. The pixel position (from the left end of the image) at the center in the horizontal (x-axis) direction is calculated, and the calculated content is held in an internal register of the CPU 21.

Next, this time, only the LED 31 located on the left side of the lens 11 is driven by the LED driving unit 29 to turn on and off.
The subject 32 is irradiated with a green light beam (step B06).

Then, the center position of the green beam spot in the image data obtained in this state is calculated for each pixel (step B07), and then the light emission from the LED 31 is canceled (step B08).

Here, the center position of the beam spot is calculated by a general conversion operation for converting a YUV signal into an RGB signal, and only the G signal is obtained. After obtaining the portion of the substantially circular pattern, the pixel position (from the left end of the image) at the center in the horizontal (x-axis) direction of the image is calculated as the center position. Hold in a register.

Next, subtraction is performed by subtracting the pixel position at the center of the green light beam spot from the pixel position at the center of the red light beam spot held in the internal register, and the lens 11 is determined by the difference in the number of pixels. The distance between the object and the subject 32 is calculated (step B09).

FIG. 6 shows an example of a method of calculating the distance at this time. In this example, the range in which the digital camera 10 can perform macro photography is a distance between the lens 11 and the subject 32 of 8 cm to 12 cm. And

For example, if the distance between the lens 11 and the CCD 12 is 10 cm, if the LEDs 30 and 31 are simultaneously turned on, the red and green light beams are preset so as to intersect. Is "0", which indicates that the distance "10 cm" between the lens 11 and the subject 32 is calculated.

The relationship shown in FIG. 6 can be obtained by a simple arithmetic expression.
Then, after the focus position of the lens 11 is variably set according to the distance between the lens 11 and the subject 32 obtained in this way, the lens is driven by the lens driving unit 33 (step B10), and The operation waits for a push operation (step B11).

When it is determined that the shutter key has been fully pressed, an image pickup operation is executed (step B1).
2).

As described above, the size of the subject 32 in the image can be arbitrarily changed within the range in which the lens 11 can focus, so that the user can select a desired composition and can obtain an accurate focus. Macro photography can be more easily utilized without the need for an operation to obtain focus.

In the second embodiment, the camera in which the focusable range in macro photography has a certain width has been described. However, as in the camera described in the first embodiment, Even in a camera in which the focusable distance in macro shooting is fixed, the above-described step B03
From the value of the distance between the lens 11 and the subject 32 calculated in the processing of B09 to B09, for example, a message is displayed on the display unit 25 to indicate in which direction and how much the digital camera 10 should be moved, so that accurate positioning is performed. Can be performed easily, and it can be more user-friendly and highly productive.

In the first and second embodiments, the light beams are emitted by using the LEDs 30 and 31. However, the means for generating the light beams is not limited to the LEDs, and may be, for example, a laser oscillator or the like. May be used.

Further, in the second embodiment, the order of light beam emission is shown as red and green, but the order may be reversed, or each light beam may be emitted at the same time to calculate the center position of a circle.

In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0069]

According to the first aspect of the present invention, if the beam emitting means is provided in advance so as to intersect at the macro shooting distance of the lens, the coincidence / non-coincidence of a plurality of light beams irradiated on the object is obtained. An accurate in-focus state can be easily confirmed, and the emission of the light beam is stopped at the time of shooting, so that the light beam does not appear in a shot image.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, when a plurality of light beams do not coincide with each other on the subject, which direction is determined based on the positional relationship of the colors. It can be easily determined whether the original in-focus position is deviated, so that the alignment becomes easier.

According to the third aspect of the present invention, in addition to the effect of the first aspect of the present invention, the light beam irradiated on the subject is not directly viewed but is confirmed on the monitor display screen for photographing. This makes macro photography easier.

According to the fourth aspect of the invention, in addition to the effect of the second aspect, the size of the subject in the image can be arbitrarily varied within the focusing range of the photographing lens. A desired composition can be selected, and an operation for obtaining accurate focusing is not required, and macro shooting can be more easily utilized.

According to the fifth aspect of the present invention, in addition to the effect of the second aspect of the present invention, accurate positioning can be performed only by changing the position of the imaging device as instructed by the instructing means. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a circuit configuration according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a lens, an LED, a CCD and a subject in FIG. 1;

FIG. 3 is a flowchart showing processing contents during macro shooting according to the embodiment;

FIG. 4 is a diagram illustrating an operation according to the embodiment.

FIG. 5 is a flowchart showing processing contents at the time of macro shooting according to the second embodiment of the present invention.

FIG. 6 is an exemplary view for explaining a distance calculation method according to the embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Digital camera 11 ... Lens 12 ... CCD 13 ... Timing generator (TG) 14 ... Vertical driver 15 ... Sample hold circuit (S / H) 16 ... A / D converter 17 ... Color process circuit 18 ... DMA controller 19 ... DRAM interface 20 ... DRAM 21 ... CPU 22 ... VRAM controller 23 ... VRAM 24 ... Digital video encoder 25 ... Display unit 26 ... Key input unit 27 ... JPEG circuit 28 ... Flash memory 29 ... LED drive unit 30, 31 ... LED 32 ... Subject 33 ... Lens drive unit

Claims (5)

[Claims] 1. A plurality of beam light emitting means provided so that light beams intersect at a specific distance position in a photographing area, and light emission control means for controlling light emission timing of the light beam by the beam light emitting means. An imaging device, comprising: 2. The image pickup apparatus according to claim 1, wherein said plurality of beam emitting means emit light beams of different colors. 3. The image pickup apparatus according to claim 1, further comprising a display unit for displaying an image of the photographing area on a monitor. 4. A calculating means for calculating a distance between respective spot center positions of a plurality of light beams illuminated on a subject by the plurality of light emitting means; a result obtained by the calculating means; 3. The imaging apparatus according to claim 2, further comprising a focus control unit that variably sets a focus position of the photographing lens according to a positional relationship between a plurality of light beams. 5. A calculating means for calculating a distance between respective spot center positions of a plurality of light beams irradiated on a subject by the plurality of light emitting means; and a result obtained by the calculating means, 3. An apparatus according to claim 2, further comprising: an instruction unit configured to indicate a photographing position based on a positional relationship between colors of the plurality of light beams.
An imaging device according to any one of the preceding claims.