JP2005077934A - Auxiliary light projection device and camera with same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an auxiliary light projection device which controls the color and quantity of auxiliary light irradiating a subject according to the color of a subject, and provide a camera having the same. <P>SOLUTION: An auxiliary light projection device (8, 9)which is mounted on or incorporated in a camera A having a focus detecting means 7 of detecting a focus by using reflected light from a subject or can communicate with the camera includes a light projecting means 9 of projecting the auxiliary light on the subject, a colorimetric means 7 of detecting the color of the subject, and a control means 8 of controlling light emission of the light projecting means according to color information from the colorimetric means 7. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an auxiliary light projector that emits auxiliary light for automatic focus detection of a camera and a camera including the same.

Conventionally, a TTL phase difference detection method or a contrast detection method is used in a camera having an automatic focus detection function. At this time, when the subject brightness or contrast is low or focus detection cannot be performed, the subject is irradiated with a light source such as an LED or a flash built in the camera as auxiliary light to compensate for the subject brightness and contrast. It has been proposed to perform automatic focus detection (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 9-15490

  In the conventional method, when the subject is irradiated with an LED, a flash, or the like as auxiliary light, monochromatic auxiliary light is irradiated regardless of the color of the subject. For this reason, depending on the combination of the color of the subject and the color of the auxiliary light, sufficient brightness and contrast cannot be obtained, and there is a possibility that accurate focus adjustment cannot be performed.

  The present invention has been made in view of the above problems, and provides an auxiliary light projecting device that controls the color and amount of auxiliary light irradiated to a subject according to the color of the subject, and a camera having the same. It is an object.

  In order to achieve the above object, according to the present invention, in the auxiliary light projector that is attached to or built in a camera having a focus detection means for detecting a focus using reflected light from the subject, or that can communicate with the camera, the subject A projection unit for projecting auxiliary light, a color measurement unit for detecting the color of the object, and a control unit for controlling the light emission of the projection unit based on color information from the color measurement unit. There is provided an auxiliary light projecting device.

  In the auxiliary light projecting device according to the present invention, it is preferable that the light projecting unit includes a light emitting unit capable of emitting a plurality of colors.

  In the auxiliary light projecting device according to the present invention, it is preferable that the light projecting unit is integrally formed with light emitting portions of two or more colors.

  In the auxiliary light projecting device according to the present invention, it is preferable that the control unit controls a light emission amount of the same color as the color of the subject.

  According to the present invention, there is provided a camera comprising the auxiliary light projector.

  According to the present invention, it is possible to provide an auxiliary light projecting device that controls the color and the amount of auxiliary light that is applied to the subject according to the color of the subject, and a camera having the same.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a camera according to an embodiment of the present invention. FIG. 2 is a front external view of the camera according to the embodiment of the present invention. FIG. 3 is a flowchart showing the operation of the camera. FIG. 4 shows an example of an auxiliary light lighting circuit and an auxiliary light emitting unit.

  1 and 2, reference numeral 1 denotes a microcomputer that controls the operation of each part of the camera. The photometry circuit 12 measures the reflected light from the subject incident on the lens 4 to detect the luminance of the subject, and transmits it to the microcomputer 1 as luminance information. The microcomputer 1 emits auxiliary light based on the luminance information from the photometry circuit 12 so as to give the luminance and contrast of the subject necessary for focus detection described later.

  The color measurement unit 2 detects the color of the subject incident on the lens 4 and transmits color information for each portion of the subject to the microcomputer 1. Based on the color information from the color measurement unit 2, the microcomputer 1 determines the emission color of auxiliary light, which will be described later, and emits auxiliary light.

  The lens control device 3 performs the focusing operation and aperture control operation of the lens 4 on the lens 4 in accordance with instructions from the microcomputer 1.

  The flash light emitting circuit 5 controls the flash light emission to the subject by applying a voltage to the flash light emitting unit 6 according to the brightness of the subject (not shown) according to an instruction from the microcomputer 1.

  The focus detection unit 7 accumulates the reflected light from the subject incident on the camera via the lens 4, detects the defocus of the lens 4 by the existing phase difference detection method, and detects the defocus of the lens 4 with respect to the microcomputer 1. Communicate information. Based on the defocus information from the focus detection unit 7, a control instruction for the lens 4 is transmitted from the microcomputer 7 to the lens control device 3, and the lens 4 is driven to perform a focusing operation. Further, when focus detection (ranging operation) cannot be performed due to insufficient brightness or contrast of the subject, information indicating that focus detection is impossible is transmitted to the microcomputer 1.

  The auxiliary light lighting control device 8 applies a driving voltage to the auxiliary light emitting unit 9 in accordance with an instruction from the microcomputer 1 when the subject brightness or contrast is low or the focus detection unit 7 cannot detect the focus. Light is emitted toward the subject. The color of the auxiliary light is instructed from the microcomputer 1 based on the color information from the color measurement unit 2. Based on the luminance information from the photometry circuit 12, the microcomputer 1 calculates the optimum light amount based on the luminance information from the photometry circuit 12 and gives the auxiliary light lighting control device 8 a light emission amount instruction. The auxiliary light lighting control device 8 and the auxiliary light emitting unit 9 constitute an auxiliary light projector.

  The feeding unit 10 finishes a predetermined sequence such as focus detection in a state where the photographer presses the release switch 13 halfway, and releases the shutter by fully pressing the release switch 13 to capture the subject image on the film. The film is fed by the instruction of the microcomputer 1 to prepare for the next shooting.

  The shutter unit 11 is a unit that controls a shutter operation for exposure according to an instruction from the microcomputer 1 that detects the depression of the release switch 13. In this way, the camera A is configured.

  In the present embodiment, the microcomputer 1 determines the luminance information of the reflected light from the subject incident on the lens 4 from the photometric circuit 12 and the colorimetric unit 2 based on the information indicating that the focus cannot be detected from the focus detection unit 7. Based on the color information of the subject, the auxiliary light lighting control device 8 determines the light emission color and the light emission amount of the auxiliary light emitting unit 9 for obtaining the luminance on the subject necessary for focus detection by the focus detection unit 7. To direct. The auxiliary light lighting control device 8 sets a driving voltage to the auxiliary light emitting unit 9 and emits auxiliary light.

  As a result, the auxiliary light is applied to the subject, and the focus detection unit 7 can accurately perform the focusing operation on the subject. At this time, auxiliary light having the same color as that of the subject is irradiated on the subject according to the color information of the subject from the color measurement unit 2. For example, when the color of the subject is red, the amount of reflected light from the subject incident on the lens 4 is increased by setting the color of the auxiliary light to red so that the brightness or contrast necessary for focus detection can be ensured. Become. When the subject is achromatic such as white, black, or gray, it is preferable to emit white light.

  In addition, when the pattern-shaped auxiliary light is irradiated, the amount of reflected light from the subject of the same color increases, and a luminance or contrast difference occurs at the boundary between the portion irradiated with the auxiliary light and the portion not irradiated. This makes it possible to perform accurate focus detection.

  Next, the operation of the camera according to the present embodiment will be described with reference to FIGS. FIG. 3 shows an operation flowchart of the camera according to the present embodiment, and FIG. 4 shows an example of the auxiliary light lighting circuit 8 and the auxiliary light emitting unit 9.

  The operation of the camera will be described below according to the flowchart. The start is shown when the camera is turned on and the release switch 13 is half-pressed. Hereinafter, each step will be described.

● Step S1
When the release switch 13 is pressed halfway, the photometry circuit 12 measures the brightness of the reflected light from the subject incident on the lens 4 and transmits the result to the microcomputer 1. Further, the focus detection unit 7 performs focus detection (ranging) of the subject.

● Step S2
The microcomputer 1 determines whether or not it is necessary to irradiate the subject with the auxiliary light based on the distance measurement availability information from the focus detection unit 7. If the subject has sufficient brightness and the distance measuring operation (focus detection) is possible, the auxiliary light irradiation is unnecessary, and the process jumps to step S6. If the luminance of the subject is insufficient for performing the distance measuring operation (focus detection), step S3 is executed.

● Step S3
The color measurement unit 2 detects the color of each part of the subject and transmits it to the microcomputer 1 as color information.

● Step S4
The microcomputer 1 calculates the amount of light to compensate for the insufficient luminance of the focus detection unit 7 from the color information from the colorimetry unit 2 and the luminance information from the photometry circuit 12, and the emission color and emission of the auxiliary light To the auxiliary light lighting control device 8. In response to an instruction from the microcomputer 1, the auxiliary light lighting control device 8 has red R (9a), green G (9b), and blue B (9c) so that the auxiliary light emitting unit 9 has a predetermined emission color and emission amount. ) For each color light source.

● Step S5
The drive voltage is set from the auxiliary light lighting control device 8, and the auxiliary light emitting unit 9 emits auxiliary light of the emission color and emission amount set toward the subject.

● Step S6
While the auxiliary light is irradiated, focus detection is performed by the focus detection unit 7, and focus detection deviation information is transmitted to the microcomputer 1.

● Step S7
The microcomputer 1 determines whether the lens 4 is focused on the subject. If not in focus, the process proceeds to step S8. If in focus, the process proceeds to step S9.

● Step S8
When not in focus, the microcomputer 1 transmits a driving instruction for the lens 4 to the lens control device 3 to drive the lens 4 and returns to step 6. Steps S6 to S8 are repeated until the subject is in focus.

● Step S9
Whether to use the flash is determined according to the brightness of the subject and the photographer's settings. If the flash is not used, the process proceeds to step S11. If the flash is used, the process proceeds to step S10.

● Step S10
The microcomputer 1 instructs the flash circuit 5 to charge the flash light emitting unit 6 for light emission, and the flash circuit 5 charges the flash light emitting unit 6.

● Step S11
The state of the release switch 13 is determined. If the release switch 13 is half pressed, the steps from Step S1 to Step S11 are repeated. When the release switch 13 is fully pressed and turned on, step S12 is executed.

● Step S12
When the release switch 13 is fully pressed, the shutter unit 11 is driven to expose the subject image onto the film. When the flash is set to be used, flash emission from the flash emission unit 6 is performed simultaneously with the driving of the shutter unit 11. Expose the subject image on the film. When the flash use is not set, the shutter unit 11 is driven to expose the subject image on the film.

● Step S13
After the exposure of the subject image on the film, the feeding unit 10 is driven to feed the film in preparation for the next shooting, and the process returns to step S1 to complete a series of shooting operations.

  In this way, it is possible to provide a camera with a built-in auxiliary light projector that can irradiate the subject with auxiliary light corresponding to the color of the subject.

  The auxiliary light projector described above is not limited to being built in the camera, and may be externally attached to the camera or provided to be communicable with the camera.

  The auxiliary light emitting unit 9 of FIG. 4 has been described with respect to the case where each of the R (9a), G (9b), and B (9c) light sources is provided. 9 may be used.

  Further, four filters of R, G, B and colorless may be provided on the subject side of the light source that emits white light, and the filter may be switched to a filter corresponding to the color to be irradiated.

  The above-described embodiment is merely an example, and is not limited to the above-described configuration and shape, and can be appropriately modified and changed within the scope of the present invention.

It is a block diagram which shows the structure of the camera which concerns on embodiment of this invention. 1 is a front external view of a camera according to an embodiment of the present invention. It is a flowchart figure which shows operation | movement of a camera. An example of an auxiliary light lighting circuit and an auxiliary light emitting unit is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Microcomputer 2 Color measuring unit 3 Lens control apparatus 4 Lens 5 Flash light emission circuit 6 Flash light emission part 7 Focus detection unit 8 Auxiliary light lighting control apparatus 9 Auxiliary light emission apparatus (auxiliary light emission part)
10 Feed unit 11 Shutter unit 12 Photometric circuit 13 Release switch

Claims (5)

In an auxiliary light projector that is attached to or built in a camera having a focus detection means for detecting focus using reflected light from a subject, or that can communicate with the camera,
A light projecting means for projecting auxiliary light onto the subject;
Colorimetric means for detecting the color of the subject;
An auxiliary light projecting device comprising: control means for controlling light emission of the light projecting means based on color information from the color measuring means.   The auxiliary light projector according to claim 1, wherein the light projecting unit includes a light emitting unit capable of emitting a plurality of colors.   The auxiliary light projector according to claim 2, wherein the light projecting unit is formed integrally with light emitting units of two or more colors.   The auxiliary light projector according to claim 1, wherein the control unit controls a light emission amount of the same color as the color of the subject.   A camera comprising the auxiliary light projector according to any one of claims 1 to 4.

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