JP2003101846A - Electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic camera capable of picking up a required image by using a multi-field reading type image pickup element. SOLUTION: The electronic camera having the image pickup element for dividing a picture signal obtained by picking up a subject image into a plurality of fields and outputting these divided field images is provided with a successive processing means for successively sending picture signals recorded in a memory 5 to a signal processing part 6 before recording all picture signals in the memory 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic camera,
The present invention relates to an electronic camera using an image pickup device which can be divided into a plurality of fields and output.

[0002]

2. Description of the Related Art In digital still cameras and digital video cameras, image pickup devices are used as means for photoelectrically converting light from a subject.

Conventional image pickup devices are classified into an all-pixel reading system and a frame reading system according to how to output an image signal obtained by photoelectric conversion.

The all-pixel reading method is a method in which the image signals of all the pixels forming the image sensor are output in one field, that is, the signals for one image are output once.

On the other hand, the frame reading system is a system in which an image signal of a pixel forming an image pickup device is divided into two fields and outputted, that is, a signal for one image is divided into two and outputted.

However, in recent years, a so-called multi-field reading type image pickup device which divides an image signal into a plurality of fields and outputs the image signals has been proposed and attracted attention.

In such a multi-field reading method, one transfer path can be shared by a plurality of light receiving pixels, so that the image pickup pixels can be made smaller, and as a result, the image pickup device can be made smaller than the conventional image pickup device. Attention has been paid to the fact that a high-resolution image can be captured because the light-receiving pixel can be enlarged.

However, while the multi-field readout type image pickup device has the above-mentioned merits, since the transfer path is shared, the image pickup device is used for an electronic camera to obtain an image. In this case, the conventional signal processing method has a problem that a desired image cannot be obtained.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic camera capable of picking up a desired image by using a multi-field reading type image pickup device.

Other objects of the present invention will be clarified by the following description of the present specification.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and the invention according to claim 1 divides an image signal obtained by picking up a subject image into a plurality of fields and outputs it. An electronic camera having an image pickup element, characterized in that it has a sequential processing means for sequentially sending the image signals recorded in the memory to a signal processing unit before all the image signals are recorded in the memory. .

According to a second aspect of the present invention, the sequential processing means sequentially sends the image signals recorded in the memory to the signal processing unit when the image signals necessary for image adjustment are recorded in the memory. The electronic camera according to claim 1.

According to a third aspect of the present invention, the sequential processing means sequentially sends the image signals recorded in the memory to the signal processing unit at the time when the image signals capable of forming a thumbnail image are recorded in the memory. The electronic camera according to claim 1, wherein:

According to a fourth aspect of the present invention, the sequential processing means sequentially outputs the image signals recorded in the memory to the signal processing unit at the time when the image signal capable of creating an instant view image is recorded in the memory. The electronic camera according to claim 1, wherein the electronic camera transmits the electronic camera.

According to a fifth aspect of the present invention, the sequential processing means outputs an image signal recorded in the memory when the image signal capable of forming an image not requiring all pixels is recorded in the memory. The electronic camera according to claim 1, wherein the electronic camera is sequentially sent to the processing unit.

According to a sixth aspect of the present invention, there is provided an electronic camera having an image pickup device which divides an image signal obtained by picking up a subject image into a plurality of fields and outputs the divided image signals. An electronic camera having a correction means.

According to a seventh aspect of the present invention, the correction means performs different correction for each read field by strengthening the noise cancellation as the image signal of the field read out later is increased. It is the electronic camera described.

The invention according to claim 8 is the electronic camera according to claim 6, wherein the correction means performs different correction for each read field by changing the signal level for each read field. .

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

First, a schematic structure of the electronic camera of the present invention will be described with reference to FIGS.

FIG. 1 is a block diagram showing a schematic structure of an electronic camera of the present invention, and FIGS. 2 and 3 are views for explaining an image pickup device according to the electronic camera of the present invention. In FIG. 1, 1 is a lens, 2 is a CCD, and 3 is A /
D converter, 4 is a memory controller, 5 is a memory, 6 is a signal processing unit, 7 is an image display unit, 8 is an external I / F, and 9 is a memory card. Reference numeral 10 is a control unit.

The lens 1 is composed of a plurality of lenses that cooperate to form an image of a subject.

The CCD 2 corresponds to the image pickup device of the present invention,
The object image formed by the lens 1 is received, the electric charge obtained by photoelectrically converting the received light is accumulated, and the electric charge is output as an analog image signal by a transfer pulse from the control unit 10.

In the present invention, a CC corresponding to the image pickup device
D2 forms a unit area by providing one transfer path (charge discharging section) for a predetermined number of light receiving pixels that are determined by three or more light receiving object images, and by providing a plurality of the unit areas. It is configured.

The image pickup device divides the image signal into a plurality of fields and outputs the image signal, that is, outputs the image signal from only one of the plurality of light receiving pixels in each unit area in one output.

An image pickup device that can be used in the electronic camera of the present invention will now be described with reference to FIGS. 2 and 3. In FIG. 2, a large number of light receiving elements 20a, 20b, 20c ... It is a pixel, which receives the imaged subject and performs photoelectric conversion. Each light receiving pixel 2
0a, 20b, 20c ... Are respectively provided with color filters made of various colors (R, Gb, Gr, B in the drawing) that constitute the colors of the image. Light receiving pixels 20a, 20b, 2
0c ... Temporarily stores electric charges obtained by photoelectrically converting the received subject image. The accumulated charges are read to the adjacent vertical transfer paths 21a and 21b at regular intervals, and the charges read to the vertical transfer paths 21a and 21b are transferred to the horizontal transfer path 2
2 and is output from the output buffer 23 to the outside of the image sensor.

The image pickup device used in the present invention includes the vertical transfer paths 21a, 2a from the respective light receiving pixels 20a, 20b, 20c.
It is characterized in that the timing at which the charges are read to 1b is read three times or more for one image. That is, the image pickup device used in the present invention uses an image pickup device that outputs an image signal for one image in three or more times (hereinafter, also referred to as three fields or more) when outputting the image signal. For example, in the example of FIG.
The image signal for the image is output. Further, in the example of FIG. 3, the image signal for one image is output by being divided into four fields.

Such an image pickup device may have one vertical transfer path for a predetermined number of light receiving pixels. 1
The term “one vertical transfer path” means that a plurality of light receiving pixels conventionally requires a number of charge discharging portions (discharge areas) corresponding to the light receiving pixels. Since the charges are sequentially discharged from the light receiving pixels, the charge discharging portion (discharge area) required for a predetermined number of light receiving pixels has only to transfer the charges discharged from one light receiving pixel. For example, in the example of FIG. 2, the imaging pixels 20a, 20b, 2
It is only necessary to have at least one vertical transfer path for 0c, and in the example of FIG. 3, the imaging pixels 20a, 20b, 20
It is only necessary to have at least one vertical transfer path for c and 20d. The vertical transfer path can be shared by the light receiving pixels according to the number of divided fields.

As described above, in the image pickup device used in the present invention, it is only necessary to sequentially output charges from a predetermined number of light receiving pixels to one vertical transfer path, and therefore, a plurality of light receiving pixels share one vertical transfer path. can do. Therefore, the area required for the vertical transfer path can be reduced compared to the conventional image sensor,
The image sensor can be downsized as a whole.

The A / D converter 3 converts the analog image signal output from the CCD 2 into a digital image signal.

The memory controller 4 includes an A / D converter 3
The digital image signal converted in step 1 is recorded in the memory 5, and the image signal recorded in the memory 5 is sent to the signal processor 6 for signal processing.

The memory 5 is a storage means for temporarily recording the digitized image signal.

The signal processing unit 6 performs signal processing such as luminance processing and color processing on the image signal sent from the memory controller 4 and temporarily recorded in the memory 5.

The image display section 7 displays the image of the image signal processed by the signal processing section 6.

The external I / F 8 is an external connection means for transferring the image signal processed by the signal processing unit 6 to an external medium of the electronic camera body.

The memory card 9 is a memory card which is a type of external medium.

Next, a first mode of the electronic camera of the present invention will be described.

A first form of the electronic camera of the present invention is an electronic camera having an image pickup device for dividing an image signal obtained by picking up a subject image into a plurality of fields and outputting the divided field.
It is characterized in that it has a sequential processing means for sequentially transmitting the image signals recorded in the memory to the signal processing section before all the image signals are recorded in the memory, preferably 1) the sequential processing means is necessary for image adjustment. When the image signals are recorded in the memory, the image signals recorded in the memory are sequentially sent to the signal processing unit. 2) The sequential processing means records the image signals capable of creating thumbnail images in the memory. The image signals recorded in the memory are sequentially transmitted to the signal processing unit at a time point 3), and the sequential processing unit is recorded in the memory when the image signal capable of forming the instant view image is recorded in the memory. 4) sequentially transmitting the image signals to the signal processing unit, and 4) the sequential processing means is capable of forming an image that does not require all pixels, at the time when the image signals are recorded in the memory. Wherein the sequentially sends that image signals recorded in the memory to the signal processor.

The electronic camera of the first embodiment will be described with reference to FIG.

A subject image is formed by the lens 1, and the subject image picked up by the CCD 2 corresponding to the image pickup device of the present invention is photoelectrically converted to obtain an image signal. At this time, the image signal obtained by the CCD 2 is divided into a plurality of fields and outputted, and is recorded in the memory 5 by the memory controller 4.

In this embodiment, the memory controller 4 shown in FIG. 1 corresponds to the sequential processing means. The memory controller 4 sequentially sends the image signals recorded in the memory 5 as described above to the signal processing unit 6 before all the image signals of the captured subject image are recorded in the memory.

The timing at which the memory controller 4 sequentially sends the image signals recorded in the memory 5 to the signal processor 6 is as follows.
1) When an image signal necessary for image adjustment is recorded in the memory 5, 2) When an image signal capable of producing a thumbnail image is recorded in the memory 5, 3) An instant view image can be produced It is preferable to be any one of the time point when the image signal is recorded in the memory 5 and the time point when 4) the image signal capable of forming an image not requiring all pixels is recorded in the memory.

In the present invention, “sequentially sending” means sending image signals recorded in the memory 5 so that the signal processing unit 6 can perform signal processing.

The timings at which the memory controller 4 sequentially sends the image signals recorded in the memory 5 to the signal processor 6 will be described below with reference to FIGS. 3 and 4.

1) Image signals necessary for image adjustment are stored in the memory 5
When recorded in

The "image signal necessary for image adjustment" means an image signal that can calculate, for example, a gradation conversion coefficient and WB (white balance) data.

The "gradation conversion coefficient" is a coefficient necessary for signal processing for adjusting the brightness of an image. This is for correcting bright when the image is captured darkly and darkly when the image is captured brightly, and is obtained by calculating the brightness of the image as in the case of AE (automatic exposure). The calculation of the gradation conversion coefficient can be performed from a part of the image.

The "WB (white balance) data" is a coefficient necessary for signal processing for adjusting the white balance of an image. Examples of such WB data include R gain and B gain. It can be calculated by measuring the color balance of the image in the same manner as AWB (auto white balance). All pixels on the entire surface are not required to calculate such WB data.
It is possible to perform signal processing when each color data of a plurality of fields is complete.

"All color data is complete" means that the image signals for all unit colors that make up the color of the image are complete. For example, if the image color is composed of RGB,
It means that at least one image signal regarding R, G, and B is prepared.

By sending the image signal to the signal processing unit at the time when the image signal required for image adjustment is recorded in the memory, the image adjustment is performed even if the image signals divided into a plurality of fields are not accumulated for all pixels. Therefore, gradation correction and automatic white balance adjustment can be performed quickly.

For example, when outputting image signals of four colors R, Gr, Gb, and B in four fields as shown in FIGS. 3 and 4, "R" and "Gr" are aligned in the first field, and In the two fields, "Gb" and "B" are aligned. Therefore, the image signal is sent to the signal processing section when the second field is output.

After the image signal necessary for image adjustment is recorded in the memory in this way, the image signal is sent to the signal processing unit 6, and then the signal processing unit 6 collects the data necessary for image adjustment. . The data necessary for adjusting such an image is
For example, gradation conversion coefficient, WB (white balance) data, etc. may be mentioned.

2) When an image signal capable of producing a thumbnail image is recorded in the memory 5

The thumbnail image refers to a graphic view in which the image of the graphic file is miniaturized and simplified by thinning out pixels, for example, a small size image of 160 dots × 120 dots.

For example, in the case of outputting a 4-field image signal as shown in FIG. 4, at the time when an image signal capable of producing a thumbnail image is recorded in the memory, not at all 4 fields, for example, when the second field is recorded. The image signal is sent to the signal processing unit.

When an image signal capable of forming a thumbnail image is recorded in the memory and the image signal is sent to the signal processing unit, all pixels on the entire surface of the image signal divided into a plurality of fields are displayed. Since the signal processing can be started at the time when the necessary part of the image signal is stored even if it is not stored, the processing time for the image processing can be shortened.

3) When an image signal capable of creating an instant view image is recorded in the memory 5

The instant view image means immediately after the image pickup,
It refers to a small size image displayed on the monitor LCD for confirming the captured image.

For example, in the case of outputting a 4-field image signal as shown in FIG. 4, not all four fields but an image signal capable of producing an instant view image is recorded in the memory, for example, the second field is recorded. The image signal is sent to the signal processing section.

When the image signal capable of forming an instant view image is recorded in the memory, the image signal is sent to the image processing section. Since the signal processing can be started at the time when the necessary part of the image signal is stored even if the image is not stored, the processing time for the image processing can be shortened.

4) The sequential processing means is a time point when an image signal capable of forming an image not requiring all pixels is recorded in the memory.

An image which does not require all pixels is, for example, 2
It refers to a reduced image created by VGA (640 dots × 480 dots) with a camera of, 000,000 pixels.

For example, in the case of outputting a 4-field image signal as shown in FIG. 4, not all of the 4 fields but an image signal capable of forming an image not requiring all pixels is recorded in the memory, for example, the second field is The image signal is sent to the signal processing unit at the time of recording.

If the image signal is sent to the image processing unit at the time when the image signal capable of forming an image not requiring all pixels is recorded in the memory, among the image signals divided into a plurality of fields, Even if not all pixels on the entire surface are accumulated, the signal processing can be started at the time when a necessary portion of the image signal is accumulated, so that the processing time for image processing can be shortened.

The image signals sequentially sent to the signal processing unit 6 by the memory controller 4 as described above are subjected to signal processing in the signal processing unit 6 so that a desired image can be obtained.

Next, a second mode of the electronic camera of the present invention will be described.

A second form of the electronic camera of the present invention is an electronic camera having an image pickup device for dividing an image signal obtained by picking up a subject image into a plurality of fields and outputting the divided field.
It is characterized by having a correction means for performing different correction for each read field, preferably 1) the correction means makes different correction for each read field by making noise cancellation stronger as the image signal of the field read out later. 2) the correction means
It is characterized in that different correction is performed for each read field by changing the signal level.

A second form of such an electronic camera will be described with reference to FIG.

A subject image is formed by the lens 1, and the subject image picked up by the CCD 2 corresponding to the image pickup device of the present invention is photoelectrically converted to obtain an image signal. At this time, the image signal obtained by the CCD 2 is divided into a plurality of fields and outputted, and is recorded in the memory 5 by the memory controller 4.

In the present embodiment, the memory controller 4 shown in FIG. 1 corresponds to the correction means. When recording the image signal in the memory 5 as described above, the memory controller 4 performs different corrections on the image signal for each read field.

When the memory controller 4 corrects the image signal differently for each read field, the noise cancellation is strengthened as the image signal of the field read out later is changed, or the signal level is changed so that it is different for each read field. It is preferable to make a correction.

It is preferable to increase the noise cancellation so that the image signal of the field read out later is stronger, because an image less affected by noise can be obtained. When the image is read by dividing it into a plurality of fields, the electric field is read out later, the longer the charge is accumulated in the photoelectric conversion unit, but the photoelectric conversion unit generates noise even when the light is shielded. Therefore, the field signal read out later has more noise.

When performing noise cancellation, for example, a low pass filter or the like can be used. Therefore, it is possible to perform desired noise cancellation by using a low-pass filter that is stronger as it comes later in the image signal read separately in a plurality of fields.

It is preferable to change the signal level for each read field because it is possible to obtain an image with little influence of the change in gain level. When the image is read out by dividing it into a plurality of fields, the more the field signal read out later, the longer the electric charge is accumulated in the photoelectric conversion section. However, when the photoelectric conversion section is shielded from light, the signal naturally appears. Because of the leakage, the signal level becomes lower as the field signal is read later.

When the signal level is changed for each read field, it is preferable to increase the gain level as the field signal is read later. At this time, it is more preferable to increase the gain level by multiplying the coefficient according to the read time.

[0076]

As described above, according to the present invention, it is possible to provide an electronic camera capable of picking up a desired image by using an image pickup device of a multi-field reading system.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an electronic camera of the present invention.

FIG. 2 is a diagram for explaining an image sensor according to the electronic camera of the present invention.

FIG. 3 is a diagram for explaining an image sensor according to the electronic camera of the present invention.

FIG. 4 is a timing chart when reading an image signal in four fields.

[Explanation of symbols]

1: Lens 2: CCD 3: A / D converter 4: Memory controller 5: Memory 6: Signal processing unit 7: Image display section 8: External I / F 9: Memory card 10: Control unit 20a, 20b, 20c ...: Light receiving pixels 21a, 21b: Vertical transfer path 22: Horizontal transfer path 23: Output buffer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masahisa Mashima             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             Inside the company (72) Inventor Etsuko Rokutanda             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             Inside the company F-term (reference) 5C022 AA13 AB00 AC42 AC69

Claims (8)

[Claims] 1. An electronic camera having an image pickup device for dividing an image signal obtained by picking up a subject image into a plurality of fields and outputting the divided field, wherein all image signals are recorded in a memory before being recorded in the memory. An electronic camera having a sequential processing means for sequentially transmitting the generated image signals to a signal processing unit. 2. The sequential processing means, when the image signal required for image adjustment is recorded in the memory, sequentially sends the image signal recorded in the memory to the signal processing section. Electronic camera. 3. The sequential processing means, when an image signal capable of forming a thumbnail image is recorded in the memory, sequentially sends the image signal recorded in the memory to the signal processing unit. The electronic camera according to 1. 4. The sequential processing means, when an image signal capable of creating an instant view image is recorded in the memory, sequentially sends the image signal recorded in the memory to the signal processing unit. Item 1. The electronic camera according to Item 1. 5. The sequential processing means sequentially sends the image signals recorded in the memory to the signal processing unit at the time when the image signals capable of forming an image not requiring all pixels are recorded in the memory. The electronic camera according to claim 1, which is characterized in that. 6. An electronic camera having an image pickup device which divides an image signal obtained by picking up a subject image into a plurality of fields and outputs the divided image field, the correction means performing a different correction for each read field. And electronic camera. 7. The electronic camera according to claim 6, wherein the correction means performs different correction for each read field by strengthening the noise cancellation as the image signal of the field read later is increased. 8. The electronic camera according to claim 6, wherein the correction means performs a different correction for each read field by changing a signal level for each read shield.