JP2001050724A - 3d image detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a 3D image detecting device irradiating laser to detect a distance, presenting a warning to an imaged person before measuring distance, and detecting an obstacle to stop irradiating laser. SOLUTION: Before irradiating laser as distance measuring light from a light source 14a, an LED 22 for a self-timer is turned on. A light adjusting sensor (photo diode) for flash lamp 23 receives light of the LED 22 reflected from an obstacle or the like. A capacitor in a light adjusting circuit 29 accumulates a reverse current flowing through the light adjusting sensor for flash lamp 23. An A/D converter converts the potential of the capacitor from digital to analog to provide it for a system control circuit 35. When the potential of the capacitor is more than a prescribed value or approximately zero, the light emission of the light source 14a stops to stop the laser irradiation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a three-dimensional image detecting apparatus for detecting a three-dimensional shape of a subject using a light propagation time measuring method.

[0002]

2. Description of the Related Art Conventionally, as a three-dimensional measurement of a three-dimensional image input apparatus, an apparatus using a light propagation time measuring method is known. "Measurement Science and Technology" (S. Chr
In the three-dimensional image input apparatus described in istie et al., vol. 6, p1301-1308, 1995), a pulse-modulated laser beam is irradiated on an object to be measured, and the reflected light is provided with an image intensifier. The light is received by the two-dimensional CCD sensor and converted into an electric signal. The image intensifier is shutter-controlled by a gate pulse synchronized with the pulse emission of the laser beam. According to this configuration, the amount of light received by reflected light from a distant object to be measured is smaller than the amount of light received by reflected light from a near object to be measured. Is obtained.

On the other hand, in the device disclosed in WO 97/01111, an object to be measured is irradiated with a pulse-modulated light such as a laser beam and the reflected light is electro-optically composed of a mechanical or liquid crystal element. The light is received by a two-dimensional CCD sensor combined with a shutter and converted into an electric signal. The shutter is controlled at a timing different from the pulse of the distance measuring light, and distance information is obtained for each pixel of the CCD.

[0004]

As the distance measuring light used in these three-dimensional image detecting devices, laser light having a wavelength other than visible light is generally used. It was not known whether the distance was detected. Further, when an obstacle is present between the subject and the imaging lens, or when the distance to the subject exceeds the measurable distance, the operator may erroneously detect the distance.

According to the present invention, a person other than an operator can recognize when a laser beam is irradiated and the distance is detected, and an obstacle is present between the object and the object, and the object can be measured very close to or far away from the object. It is an object of the present invention to provide a low-cost three-dimensional image detecting device that prevents an operator from erroneously detecting a distance when the distance is outside the range.

[0006]

According to the present invention, there is provided a three-dimensional image detecting apparatus, comprising: a first light source for irradiating a subject with distance-measuring light; a first light source for receiving reflected light from the subject; An imaging unit that accumulates electric charge, a second light source that emits detection light for detecting an object toward the subject, and a detection unit that receives the detection light and accumulates a second signal charge according to the amount of received light. , First
Distance information detecting means for detecting distance information to a subject from the signal charge of the object, and object detecting means for detecting an object based on the second signal charge and determining whether or not to drive the first light source. Features.

Preferably, the distance measuring light is a laser light and the detection light is a visible light. Still more preferably, the second light source is a warning lamp for a self-timer, and the warning lamp is a light emitting diode. This makes it possible to irradiate detection light for object detection without newly providing a light emitting device for object detection.

For example, the detecting section includes a light receiving section for receiving the detection light and a storage section for storing the second signal charge. At this time, the storage unit of the detection unit is, for example, a capacitor. The light receiving section of the detecting section is a strobe light control sensor, for example, a photodiode. Thereby, detection light can be received without newly providing a light receiving device for object detection.

For example, in the object detecting means, detection light is received by a photodiode to which a reverse bias voltage is applied, a second signal charge is accumulated in a capacitor by a reverse current flowing through the photodiode, and the second signal charge is stored in the capacitor. The object is detected from the potential difference generated when the data is accumulated in the object.

Preferably, the distance detecting means is driven after driving the object detecting means. Preferably, in the object detection means, the second light source is irradiated once over a predetermined time. Thus, it can be confirmed by a person other than the operator that the distance measurement light is emitted and the distance information detection operation is driven.

Preferably, in the object detecting means, when the potential difference is equal to or more than a predetermined value or when the potential difference is substantially zero, the first
Is not driven.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a camera-type three-dimensional image detection device according to an embodiment of the present invention.

On the front of the camera body 10, a finder window 12 is provided at the upper left of the taking lens 11, and a flash 13 is provided at the upper right. On the left side of the strobe 13, a strobe light control light receiving sensor (photodiode (PD)) 23 is arranged. A light emitting diode (LED) 22 (second light source) for a self-timer is disposed on the left side of the strobe light control light receiving sensor 23. On the upper surface of the camera body 10, right above the taking lens 11, a distance measuring light emitting device (first light source) 14 for irradiating laser light, which is distance measuring light, is provided. A release switch 15 and a liquid crystal display panel 16 are provided on the left side of the light emitting device 14 for distance measurement, and a mode switching dial 17 is provided on the right side.
And a V / D mode switch 18. On the side of the camera body 10, a card insertion slot 19 for inserting a recording medium such as an IC memory card is formed, and a video output terminal 20 is provided.

FIG. 2 is a block diagram showing a circuit configuration of the camera shown in FIG. An aperture 25 is provided in the taking lens 11. The opening of the aperture 25 is determined by the iris drive circuit 2.
Adjusted by 6. The focus adjustment operation and the zooming operation of the taking lens 11 are controlled by a lens drive circuit 27.

A CCD (imaging unit) 28 is arranged on the optical axis of the taking lens 11. A subject image is formed on the CCD 28 by the photographing lens 11, and charges corresponding to the subject image are generated. Operations such as a charge accumulation operation and a charge read operation in the CCD 28 are controlled by the CCD drive circuit 30. The charge signal, that is, the image signal, read from the CCD 28 is amplified by the amplifier 31 and the A / A
The analog signal is converted into a digital signal in the D converter 32. The digital image signal is output from the imaging signal processing circuit 3
In the image memory 3, processing such as gamma correction is performed.
4 is temporarily stored. The iris drive circuit 26, lens drive circuit 27, CCD drive circuit 30, and image signal processing circuit 33 are controlled by a system control circuit 35.

The image signal is read from the image memory 34 and supplied to the LCD drive circuit 36. The LCD drive circuit 36 operates in accordance with the image signal, and thereby the image display L
An image corresponding to the image signal is displayed on the CD panel 37.

If the camera is connected to a monitor device provided outside the camera body 10 by a cable, the image memory 34
Are read from the TV signal encoder 38,
It can be transmitted to the monitor device via the video output terminal 20. The system control circuit 35 is connected to the interface circuit 40, and the interface circuit 40 is connected to the interface connector 21. Therefore, if the camera is connected to a computer provided outside the camera body 10 via an interface cable, the image signal read from the image memory 34 can be transmitted to the computer. The system control circuit 35 is connected to the image recording device 43 via the recording medium control circuit 42. Therefore, the image signal read from the image memory 34 is
Can be recorded on a recording medium M such as an IC memory card mounted on the PC.

The light emitting device 14 includes a light emitting element 14a and an illumination lens 14b. The light emitting operation of the light emitting element 14a is controlled by a light emitting element control circuit 44. Light emitting element 1
Reference numeral 4a denotes a laser diode (LD), and the emitted laser light is used as distance measuring light for detecting the distance to the subject. This laser light is applied to the entire subject through the illumination lens 14b. The laser beam reflected by the subject enters the photographic lens 11 and is detected by the CCD 28, whereby distance information to the subject is detected.

The LED 22 for the self-timer is an LED
It is controlled by the control circuit 41, and flashes and emits light when the self-timer is operated, thereby notifying the subject of the photographing timing. When the distance is detected by irradiating the laser light, the LED 22 emits light immediately before the irradiation of the laser light to warn the subject or the like that the laser light is irradiated. At this time, the light of the LED 22 reflected by the object is received by the strobe light control light receiving sensor 23 connected to the light control circuit 29 to determine whether there is an obstacle in the distance measurement or whether the subject is out of the distance measurement range. Information related to the determination is detected. The detected information is sent to the A / D converter 39, A / D converted, and output to the system control circuit 35. The strobe circuit 24 controls light emission of the strobe 13 according to a signal from the dimming circuit 29. The dimming circuit 29 and the LED control circuit 41 are controlled by the system control circuit 35.

The system control circuit 35 is connected to a switch group 45 composed of a release switch 15, a mode changeover dial 17, and a V / D mode changeover switch 18, and a liquid crystal display panel (display element) 16.

Next, the principle of distance measurement in the present embodiment will be described with reference to FIGS. FIG. 4
, The horizontal axis is time t.

The distance measuring light output from the distance measuring device B is reflected by the subject S and received by a CCD (not shown). The distance measuring light is a pulsed light having a predetermined pulse width H, and therefore, the reflected light from the subject S is also a pulsed light having the same pulse width H. The rise of the reflected light pulse is delayed by a time δ · t (δ is a delay coefficient) from the rise of the distance measuring light pulse. Since the ranging light and the reflected light have traveled twice the distance r between the distance measuring device B and the subject S, the distance r is given by r = δ · t · C / 2 (1) can get. Where C is the speed of light.

For example, a state in which reflected light can be detected from the rise of the distance measuring light pulse is determined, and the state is switched to an undetectable state before the reflected light pulse falls, that is, a reflected light detection period T is provided. And the received light amount A during the reflected light detection period T is a function of the distance r. That is, the light receiving amount A decreases as the distance r increases (the time δ · t increases).

In the present embodiment, utilizing the above-described principle,
The distance from the camera body 10 to each point on the surface of the subject S is detected by detecting the amount of received light A at each of a plurality of photodiodes provided in the CCD 28 and arranged two-dimensionally. Data of a three-dimensional image relating to a shape is input collectively.

FIG. 5 is a diagram showing the arrangement of the photodiode 51 and the vertical transfer section 52 provided on the CCD 28.
FIG. 6 is a cross-sectional view of the CCD 28 cut along a plane perpendicular to the substrate 53. This CCD 28 is a conventionally known interline type CCD, and uses a VOD for sweeping out unnecessary charges.
(Vertical overflow drain) method.

The photodiode 51 and the vertical transfer section 52 are formed along the surface of the n-type substrate 53. The photodiodes 51 are two-dimensionally arranged in a lattice, and the vertical transfer units 52 are provided adjacent to the photodiodes 51 arranged in a line in a predetermined direction (vertical direction in FIG. 5). The vertical transfer section 52 has four vertical transfer electrodes 52a, 52b, 52c, and 52d for one photodiode 51. Therefore, in the vertical transfer section 52, four potential wells can be formed, and signal charges can be output from the CCD 28 by controlling the depths of these wells as conventionally known. The number of vertical transfer electrodes can be freely changed according to the purpose.

A photodiode 51 is formed in a p-type well formed on the surface of the substrate 53, and the p-type well is completely depleted by a reverse bias voltage applied between the p-type well and the n-type substrate 53. You. In this state, charges corresponding to the amount of incident light (reflected light from the subject) are accumulated in the photodiode 51. When the substrate voltage Vsub is increased to a predetermined value or more, the electric charge accumulated in the photodiode 51 is discharged to the substrate 53 side. On the other hand, when a charge transfer signal (voltage signal) is applied to the transfer gate unit 54, the charges accumulated in the photodiode 51 are transferred to the vertical transfer unit 52. That is, after the charges are swept to the substrate 53 side by the charge sweeping signal, the signal charges accumulated in the photodiode 51 are changed by the charge transfer signal to the vertical transfer unit 5.
It is transferred to the two sides. By repeating such an operation, signal charges are integrated in the vertical transfer unit 52, and a so-called electronic shutter operation is realized.

FIG. 7 is a timing chart in the distance information detecting operation. The distance information detecting operation in the present embodiment will be described with reference to FIGS. 1, 2, and 5 to 7. In the distance information detecting operation of the present embodiment, unlike the description of the principle of the distance measurement performed with reference to FIG. 4, the distance information pulse is reflected from the falling edge of the pulse of the distance measuring light in order to reduce noise due to the influence of external light. The timing chart is configured so that the light can be detected, and the state is switched to the undetectable state after the pulse of the reflected light has fallen, but it is not different in principle.

A charge discharge signal (pulse signal) S1 is output in synchronization with the output of a vertical synchronization signal (not shown), whereby unnecessary charges stored in the photodiode 51 are discharged in the direction of the substrate 53. Then, the accumulated charge amount in the photodiode 51 becomes zero (reference S2). After the start of output of the charge sweeping signal S1, pulse-shaped ranging light S3 having a constant pulse width is output. The period (pulse width) during which the ranging light S3 is output can be adjusted.
The adjustment is performed so that the distance measurement light S3 is turned off simultaneously with the output of the charge sweeping signal S1.

The distance measuring light S3 is reflected by the object, and
It is incident on D28. That is, although the reflected light S4 from the subject is received by the CCD 28, the charge sweeping signal S1
Is not stored in the photodiode 51 (reference S2). Charge sweep signal S1
Is stopped, the photodiode 51 starts to accumulate charges by receiving the reflected light S4, and the reflected light S4
4 and the external light generate signal charges S5. When the reflected light S4 disappears (reference S6), the photodiode 51 ends the charge accumulation based on the reflected light (reference S7).
Charge accumulation due to only external light continues (reference S8).

Thereafter, when the charge transfer signal S9 is output, the charges accumulated in the photodiode 51 are transferred to the vertical transfer section 52. This charge transfer is completed when the output of the charge transfer signal ends (reference S10). In other words, the charge accumulation in the photodiode 51 continues due to the presence of external light, but the signal charge S1 accumulated in the photodiode 51 until the output of the charge transfer signal ends.
1 is transferred to the vertical transfer unit 52. The charge S14 accumulated after the output of the charge transfer signal ends remains in the photodiode 51 as it is.

As described above, the period T from the end of the output of the charge sweep signal S1 to the end of the output of the charge transfer signal S9.
_{During U1} , the photodiode 51 accumulates signal charges corresponding to the distance to the subject. Then, the reflected light S4
Until the end of light reception (reference S6), the charges accumulated in the photodiode 51 are transferred to the vertical transfer unit 52 as signal charges S12 (hatched portion) corresponding to the distance information of the subject,
Other signal charges S13 are caused only by external light.

After a predetermined time has elapsed from the output of the charge transfer signal S9, the charge sweeping signal S1 is output again, and after the transfer of the signal charge to the vertical transfer section 52, the photodiode 51
Unnecessary charges accumulated in the substrate 53 are swept toward the substrate 53.
That is, accumulation of signal charges in the photodiode 51 is newly started. Then, as described above, when the charge accumulation period T _U1 has elapsed, the signal charge is transferred to the vertical transfer unit 52.

The vertical transfer section 5 of such signal charges S11
2 is repeatedly executed until the next vertical synchronization signal is output. As a result, in the vertical transfer unit 52, the signal charge S11 is integrated, and the signal charge S11 integrated in a period of one field (a period sandwiched between two vertical synchronization signals) is regarded as a period in which the subject is stationary. If possible, it corresponds to distance information to the subject. Since the signal charge S13 is smaller than the signal charge S12, the signal charge S11 can be regarded as being equal to the signal charge S12.

The above-described operation of detecting the signal charge S11 relates to one photodiode 51, and such a detection operation is performed in all the photodiodes 51. As a result of the detection operation in the period of one field, the vertical transfer unit 52 adjacent to each photodiode 51
The distance information detected by the photodiode 51 is held in each of the parts. The distance information is output from the CCD 28 by a vertical transfer operation in the vertical transfer unit 52 and a horizontal transfer operation in a horizontal transfer unit (not shown), and is taken out of the CCD 28.

Next, the distance information detecting operation will be described with reference to FIGS. 8 and 9 which are flow charts of the distance information detecting operation.

When it is confirmed in step 101 that the release switch 15 is fully depressed, step 1 is executed.
02 is executed, video (V) mode and distance measurement (D)
It is determined which of the modes is selected. Switching between these modes is performed by operating the V / D mode switch 18.

When the D mode is selected, an obstacle detection process described later is performed in step 103. In step 104, it is determined whether or not to stop the distance measurement (distance information detection operation) based on the result of the obstacle detection processing. When the distance measurement is stopped, the program for the distance information detection operation ends immediately. If it is determined that the distance measurement (distance information detection operation) is to be continued, step 105
, A vertical synchronizing signal is output and the ranging light control is started. That is, the light emitting device 14 is driven, and the pulse-shaped ranging light S3 is output intermittently. Next, step 106 is executed, and the detection control by the CCD 28 is started. That is, the distance information detection operation described with reference to FIG. 7 is started, and the charge sweeping signal S1 and the charge transfer signal S9
Are alternately output, and the signal charge S11 of the distance information is integrated in the vertical transfer unit 52.

In step 107, it is determined whether one field period has elapsed from the start of the distance information detection operation, that is, whether a new vertical synchronizing signal has been output.
When one field period ends, the process proceeds to step 108,
The signal charge S11 of the distance information is output from the CCD. This signal charge S11 is temporarily stored in the image memory 34 in step 109. In step 110, the ranging light control is switched to the off state, and the light emitting operation of the light emitting device 14 is stopped.

In step 111, the arithmetic processing of the distance data is performed. In step 112, the distance data is stored in the recording medium M or the like, and this detection operation ends. On the other hand, when it is determined in step 102 that the V mode has been selected, the distance measuring light control is switched off in step 113, and in step 114 the normal photographing operation (CCD video control) by the CCD 28 is turned on. , And the image data captured in step 115 is stored in the recording medium M or the like, and this detection operation ends. Note that, in the V mode, photographing with the flash 13 can be performed. When photographing is performed with the flash 13, the flash dimming sensor 23 is used to control the light emission of the flash 13. In the V mode, photographing using a self-timer is also possible. When photographing with the self-timer set, the LED 22 is used as a warning lamp for the self-timer.

Next, the contents of the arithmetic processing executed in step 111 will be described with reference to FIG. It is assumed that a subject having a reflectance R is illuminated, and the subject is regarded as a secondary light source having a luminance I and is imaged on a CCD. At this time,
The output Sn obtained by integrating the charge generated in the photodiode during the charge accumulation time t is represented by the following formula: Sn = kRIt. Here, k is a proportionality constant, which varies depending on the F number, magnification, and the like of the taking lens.

As shown in FIG. 7, the charge accumulation time is T _U1 , the pulse width of the distance measuring light S3 is T _S , and the pulse width of the distance information signal charge S12 is T _D, and the charge accumulation during one field period is performed. When the time is to be repeated N times, the output SM _{10 obtained, SM 10 = Σk · R ·} I · T D = k · N · R · I · T D ··· (3) and composed. The pulse width T _D can be expressed as T _D = δ · t = 2r / C (4) At this time, the distance r to the subject can be expressed as follows: r = C · SM ₁₀ / (2 · k · N · R · I) (5) Therefore, if the proportional constant k, the reflectance R, and the luminance I are obtained in advance, the distance r can be obtained.

Next, the obstacle detection processing executed in step 103 of FIG. 8 will be described with reference to FIGS.

FIG. 10 is a block diagram showing the configuration of a circuit relating to the obstacle detection processing. The circuit configuration excluding the system control circuit 35, the strobe circuit 24, the A / D converter 39, and the photodiode (PD) (the strobe light control sensor 23) corresponds to the light control circuit 29 shown in FIG.

The photodiode 23 (light receiving portion) has 5
A reverse bias voltage of V is applied, and when light is received, a reverse current i proportional to the illuminance flows in the direction of the arrow. At this time, electric charges are accumulated in the capacitor C (accumulation portion), and a potential V is generated. The potential V is converted into a digital signal by the A / D converter 39 and output to the system control circuit 35. The voltage comparison circuit 45 compares the potential V with the reference potential V ₀ , outputs a quench signal to the strobe circuit 24 based on the difference, and controls the amount of light when the strobe 13 emits light.

The charge stored in the capacitor C is correlated with the magnitude of the reverse current i and the time it has flowed. However, the time during which the self-timer LED 22 emits light is constant, so the time during which the reverse current i flows due to the reflected light is constant, and the amount of charge stored in the capacitor C depends on the illuminance of the reflected light received by the photodiode 23. Only depends on. The illuminance of the reflected light received by the photodiode 23 is correlated with the distance of the object from which the light is reflected, and the illuminance decreases as the distance increases. Therefore, the potential V generated in the capacitor C is correlated with the distance to the object reflecting the light of the LED 22. The electric charge stored in the capacitor C is discharged by short-circuiting the switch SW.

FIG. 11 shows the relationship between the distance D to the object reflecting the light of the LED 22 and the potential V generated on the capacitor C.

In general, as the distance D to the object increases, the potential V generated in the capacitor C decreases. However, as shown in FIG. 1, the LED 22 and the photodiode 23 are spatially arranged at a constant distance. If the object is in proximity, much of the reflected light is not received by the photodiode 23, and this relationship does not hold. When the distance to the object is shorter than a certain distance (for example, on the order of the distance between the LED 22 and the photodiode 23), the shorter the distance to the object, the smaller the amount of reflected light received by the photodiode 23, which is generated in the capacitor C The value of the potential V also decreases.
That is, the potential V takes a maximum value when the distance D to the object is Dm, and decreases monotonically when the distance D is larger than Dm, but increases monotonically when the distance D is smaller than Dm. When the distance D to the object is 0, the LED 22
Is closed, the light of the LED 22 is not received by the photodiode 23, and the potential V generated in the capacitor C becomes zero. Also, when the object is extremely far away, there is almost no reflected light received by the photodiode 23, and the potential V generated in the capacitor C becomes zero.

FIG. 12 is a flowchart of the obstacle detection processing (object detection means). In step 201, after the switch SW is short-circuited and the electric charge stored in the capacitor C is discharged, the self-timer LED 22
Emit light over a period of time. The light emitted by the light emission of the LED 22 is reflected by the surface of an obstacle or a subject in front of the LED 22 when an obstacle or a subject is present, and is received by the photodiode 23.

In step 202, the photodiode 2
It is determined whether or not 3 has received the reflected light. The determination as to whether or not the reflected light has been received is made based on whether or not the potential V generated in the capacitor C is zero. The potential V becomes 0 when the vicinity of the LED 23 is covered by an obstacle such as an operator's hand or when the subject is out of the distance measurement range. Therefore, if the reflected light is not detected, a process for stopping the distance measurement is performed in step 205.

On the other hand, when the potential V generated in the capacitor C is not 0, it is determined in step 202 that reflected light has been received, and in step 203, it is determined whether or not the distance D is greater than a predetermined value Dc. The magnitude comparison between the distance D and the predetermined value Dc is performed by comparing the magnitude between the potential V and the predetermined value Vc. When the distance D is equal to or less than the predetermined value Dc, that is, when the potential V is equal to or more than the predetermined value Vc, it is determined that there is an obstacle in front of the camera or the subject is inside the distance measurement range. To stop. When the distance D is larger than the predetermined value Dc, that is, when the potential V
Is smaller than the predetermined value Vc, it is determined that there is no obstacle on the front of the camera and the subject is within the distance measurement range, and the distance measurement is continued in step 204.

As described above, in the present invention, since the self-timer LED 22 emits light immediately before the start of distance measurement, a subject other than the operator can recognize when the distance measurement is performed. In addition, since the light from the LED 22 for the self-timer is received by the photodiode 23 which is a strobe light control sensor, the presence or absence of an obstacle and whether or not the subject is within the distance measurement range are detected. There is no need to provide.

[0053]

As described above, according to the present invention, a person other than the operator can recognize when the laser beam is irradiated and the distance is detected. A three-dimensional image detection device can be obtained at low cost, in which an operator does not erroneously detect a distance when a subject is located outside a range of a distance that is extremely close or distant.

[Brief description of the drawings]

FIG. 1 is a perspective view of a camera-type three-dimensional image detection device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of the camera shown in FIG.

FIG. 3 is a diagram for explaining the principle of distance measurement using ranging light.

FIG. 4 Distance measuring light, reflected light, gate pulse, and CCD
FIG. 4 is a diagram showing a distribution of the amount of light received by the light source.

FIG. 5 is a diagram showing an arrangement of a photodiode and a vertical transfer unit provided in a CCD.

FIG. 6 is a cross-sectional view of the CCD cut along a plane perpendicular to the substrate.

FIG. 7 is a timing chart of a distance information detecting operation for detecting data relating to a distance to a subject.

FIG. 8 is a first half of a flowchart of a distance information detecting operation.

FIG. 9 is a second half of the flowchart of the distance information detecting operation.

FIG. 10 is a block diagram illustrating a configuration of a circuit related to obstacle detection processing.

FIG. 11 is a diagram showing a relationship between a distance and a potential generated in a capacitor.

FIG. 12 is a flowchart of an obstacle detection process.

[Explanation of symbols]

 14 Light Emitting Device 22 Light Emitting Diode 23 Strobe Light Control Sensor 51 Photo Diode

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Nobuhiro Tani 2-36-9 Maenocho, Itabashi-ku, Tokyo Asahi Gaku Kogyo Co., Ltd. (72) Inventor Kiyoshi Yamamoto 2-36-9 Maenocho, Itabashi-ku, Tokyo No. Asahi Gaku Kogyo Co., Ltd. F-term (reference) 2F065 AA06 AA53 BB05 EE00 FF42 FF44 GG04 GG06 GG07 GG08 JJ01 JJ03 JJ18 JJ26 LL04 LL06 LL30 NN01 NN02 NN16 QQ03 QQ14 QQ24 QQ25 QQ18 AB02 SS02 AB03 SS02

Claims (14)

[Claims] A first light source that irradiates a subject with distance measuring light; an imaging unit that receives reflected light from the subject and accumulates a first signal charge according to a received light amount; A second light source that emits detection light for detecting an object, a detection unit that receives the detection light and accumulates a second signal charge according to a received light amount, from the first signal charge to the subject Distance information detecting means for detecting the distance information, and object detecting means for detecting the object based on the second signal charge and judging whether to drive the first light source. Three-dimensional image detection device. 2. The three-dimensional image detecting apparatus according to claim 1, wherein the distance measuring light is a laser light. 3. The three-dimensional image detection device according to claim 1, wherein the detection light is visible light. 4. The three-dimensional image detection device according to claim 3, wherein the second light source is a warning lamp for a self-timer. 5. The three-dimensional image detecting device according to claim 4, wherein the warning lamp is a light emitting diode. 6. The three-dimensional image detection device according to claim 1, wherein the detection unit includes a light receiving unit that receives the detection light and a storage unit that stores the second signal charge. 7. The three-dimensional image detection device according to claim 6, wherein the storage unit of the detection unit is a capacitor. 8. The three-dimensional image detecting apparatus according to claim 6, wherein the light receiving section of the detecting section is a strobe light control sensor. 9. The three-dimensional image detection device according to claim 6, wherein the light receiving sensor for strobe light is a photodiode. 10. The object detection means, wherein the detection light is received by the reverse-biased photodiode, and the second signal charge is stored in the capacitor by a reverse current flowing through the photodiode. The three-dimensional image detection device according to claim 7, wherein the object is detected from a potential difference generated when a second signal charge is accumulated in the capacitor. 11. The three-dimensional image detecting apparatus according to claim 1, wherein the distance detecting means is driven after driving the object detecting means. 12. The object detecting means,
The three-dimensional image detection apparatus according to claim 11, wherein the light source is irradiated once over a predetermined time. 13. The three-dimensional image detecting apparatus according to claim 10, wherein the first light source is not driven when the potential difference is equal to or more than a predetermined value. 14. The three-dimensional image detecting apparatus according to claim 10, wherein the first light source is not driven when the potential difference is substantially zero in the object detecting means.