JP4437664B2 - Fundus camera - Google Patents

Description

  The present invention relates to a fundus camera used for photographing the fundus of an eye to be examined in the field of ophthalmology and the like. More specifically, the present invention relates to a fundus camera used for fluorescent fundus photography in which fundus photography is performed by intravenously injecting a fluorescent agent to a subject and receiving fluorescence emitted from a fluorescent agent that has flowed into a blood vessel in the fundus of the subject's eye. It is.

  Fundus cameras have been widely used mainly in the ophthalmic field. There are various methods for fundus photography using a fundus camera, including normal color photography and video photography, but fluorescent fundus photography (also abbreviated as fluorescence photography) that can clearly photograph the state of blood vessels in the fundus is also widely used. It's being used.

  In fluorescence imaging, imaging is performed in anticipation of a fluorescent agent intravenously injected into a vein such as a patient's arm flowing into a blood vessel of the fundus. As illumination light for illuminating the fundus, flash light including a wavelength region for exciting the fluorescent agent is used. The flash light is applied to the fundus through an exciter filter (excitation filter) that transmits the wavelength region. The fluorescent agent that has flowed into the blood vessel absorbs the flash light and emits fluorescence in a specific wavelength region. In fluorescence imaging, fundus blood vessels are imaged by receiving fluorescence from the fundus.

  In fluorescence photography, it is normal to continuously shoot the fundus by continuously flashing light at a predetermined light emission interval. As a result, fluorescence photography has various advantages, such as the fact that the flow of the fluorescent agent into the fundus blood vessels can be taken as a series of photographs to understand in detail the arrangement and branching state of the fundus blood vessels. ing.

  As a fundus camera capable of performing such fluorescence photography, for example, the one described in Patent Document 1 is known. In this document, a normal photographing mode for performing black-and-white photographing or normal color photographing, a visible fluorescent photographing mode in which a visible fluorescent agent is injected, and an infrared fluorescent photographing mode in which an infrared fluorescent agent is injected are executed. A fundus camera that illuminates the fundus with an observation light source during fundus observation, and adjusts the illumination light amount of the observation light source within a light amount region suitable for normal imaging, during the normal imaging mode. A normal illumination light amount region voltage adjusting means for adjusting the applied voltage of the observation light source, and the observation light source in the visible fluorescent photographing mode in order to adjust the illumination light amount of the observation light source within a light amount region suitable for visible fluorescent photographing. In order to adjust the illumination light quantity of the observation light source within the light quantity area suitable for infrared fluorescent photography, the visible fluorescent illumination light quantity area voltage adjustment means for adjusting the applied voltage of the light source The fundus camera includes an infrared fluorescent illumination light amount region voltage adjusting unit that adjusts an applied voltage of the observation light source, and each voltage adjusting unit is operated by one operation member.

  In such a fundus camera, the flash rate of flash light at the time of fluorescent shooting is limited to a maximum of about once per second in consideration of the exposure conditions at the time of shooting, the capacity of the capacitor, and the charging speed of the capacitor. Has been. That is, the maximum continuous shooting speed is about once per second. However, at present, there are cases in which the state of the fundus blood vessel cannot be captured in sufficient detail at such a continuous shooting speed. In particular, during the initial stage of imaging including the process in which an intravenously injected fluorescent agent flows into the fundus blood vessel (referred to as initial imaging time), it is desired to capture as many frames as possible. It was difficult to satisfy this requirement with the continuous shooting speed of the fundus camera.

  By the way, in the field of a normal camera (camera) instead of a fundus camera, a configuration for continuously flashing light at high speed and a configuration for optimizing the exposure amount of the flash light are known (for example, (See Patent Document 2 and Patent Document 3). In Patent Document 2, strobe charging is performed at the same time as the film is rolled up in the continuous shooting mode, and this is repeated for each frame until the predetermined continuous shooting frame is completed. An improved strobe continuous shooting camera is described. However, in fluorescent photographing with a fundus camera, photographing is usually performed with a TV camera, and there is no film winding process. Therefore, it is impossible to apply the configuration described in Patent Document 2 to fluorescence imaging of a fundus camera.

  Further, in Patent Document 2, it is assumed that continuous shooting at high speed is possible by performing a series of flash firing using the electric charge initially stored in the capacitor, and the light emission time from the strobe light amount and the initial voltage of the capacitor. Is described, and a continuous shooting is performed while changing the light emission time for each frame. At this time, the number of continuous shots is obtained and displayed based on information on shooting conditions such as subject distance information, lens aperture, shutter speed, ISO sensitivity, etc. and the initial voltage of the capacitor. There is an alarm output and release lock.

  Patent Document 3 discloses a stroboscope control device for a camera that illuminates a subject by discharging electric charge stored in a main capacitor with a light-emitting tube in order to prevent exposure failure during strobe flashing. The aperture value / shutter time calculating means for calculating the lens aperture value and shutter time based on the information and the film sensitivity information, and the arc tube based on the information from the aperture value / shutter time calculating means, the film sensitivity information, and the subject distance information A light amount calculating means for calculating the amount of strobe light, a voltage calculating means for calculating the voltage of the main capacitor after the light emission amount calculated by the light amount calculating means before the light emission is performed, and an arc tube Trigger means for starting the light emission, light emission stop means for stopping the light emission from the arc tube, and controlling the trigger means and the light emission stop means for a plurality of strobes. Light emission control means that enables light, continuous shooting number setting means for setting the number of continuous shooting times, and the number of continuous light emission times corresponding to the voltage charged in the main capacitor according to information from the voltage calculation means A continuous shooting number calculating means for calculating, and set when the continuous shooting number of times set by the continuous shooting number setting means exceeds the continuous flashable number of times calculated by the continuous shooting number calculating means. A strobe control device configured to change and control the continuous shooting number of times to the number of continuous light emission is described. That is, the strobe control device calculates the number of times that the strobe can be fired based on the subject luminance information, film sensitivity information (ISO), subject distance information, and charging voltage information of the main capacitor.

  However, in fluorescence imaging, it is important to capture as many frames as possible within the initial imaging time as described above, but based on the amount of charge stored in the capacitor as in the configuration described in Patent Document 3. It is difficult to apply this configuration to a fundus camera for fluorescence photography because it is not possible to deal with the time restriction of “within the initial photography time” simply by determining the number of flashes that can be emitted. The same applies to the configuration described in Patent Document 2.)

  In addition, it is preferable that the flash rate of flash light can be adjusted even after the initial photographing time has elapsed, but such a conventional configuration cannot cope with this.

  Although it is conceivable to take a moving picture of the flow of the fluorescent agent in the fundus blood vessel, the TV camera mounted on the fundus camera for fluorescence photography has a resolution of VGA (Video Graphics Array), that is, a resolution of about 300,000 pixels. Therefore, it was not enough for video shooting. In recent years, with the advancement of TV camera technology, high pixel counts and high sensitivity have been developed, and expectations for realization of movie shooting are increasing. However, it is difficult to achieve this with the current flash rate of flash light. I must.

JP 2000-316813 A ([Claims]) JP-A-8-179403 (paragraphs [0077], [0093], [0098], [0099]) JP-A-5-188438 ([Claims])

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a fundus camera capable of obtaining the number of images that can be captured in continuous imaging of fluorescent fundus imaging.

  In particular, an object of the present invention is to provide a fundus camera that can determine the number of times that an image can be taken at an initial imaging time.

  In order to achieve the above object, the invention described in claim 1 includes a light source that discharges electric charge stored in a capacitor to emit flash light, and an exciter filter that transmits a specific wavelength region of the flash light from the light source. An illumination optical system that irradiates the fundus of the subject's eye with flash light that has passed through the exciter filter, and a barrier filter that receives the flash light from the illumination optical system and transmits fluorescence emitted from the fundus. An imaging optical system that receives the fluorescence that has passed through the filter and captures a fundus image; and a charging unit that charges the capacitor. Fluorescence imaging of the fundus is performed by continuously flashing light at a predetermined emission interval. A fundus camera that performs maximum flash amount information indicating the maximum amount of charge that can be stored by the capacitor and flash light once. Discharge amount information indicating the amount of charge discharged from the capacitor, charging speed information indicating the speed at which the charging means charges the capacitor, light emission count information indicating the number of flash light emissions from the start of imaging, and imaging And a light emission number calculating means for calculating the possible number of flash light emission at the time of the elapsed time based on the elapsed time information indicating the elapsed time from the start.

  In order to achieve the above object, the invention according to claim 2 is the fundus camera according to claim 1, further comprising operating means for the user to operate start and stop of continuous fundus shooting. The light emission number calculating means calculates the number of times the flash light can be emitted at the start of the continuous shooting in response to the continuous shooting being started by the operation means.

  In order to achieve the above object, a third aspect of the present invention is the fundus camera according to the first or second aspect, wherein the flashable number of flashlights calculated by the flashing number calculating means is provided. It is further characterized by further comprising display means for displaying.

  In order to achieve the above object, the invention according to claim 4 is the fundus camera according to claim 3, wherein the display means displays the possible number of times of light emission to be displayed according to the light emission of flash light. It is characterized by decreasing.

  In order to achieve the above object, the invention according to claim 5 is the fundus camera according to claim 3 or claim 4, wherein the display means responds to charging of the capacitor by the charging means. Thus, the number of times that light can be displayed is increased.

  In order to achieve the above object, a sixth aspect of the present invention is the fundus camera according to any one of the first to fifth aspects, wherein the fluorescent agent is intravenously injected into a subject. It is characterized by comprising imaging time setting means for setting and inputting initial imaging time information indicating initial imaging time including the time when the blood flows into the blood vessels of the fundus.

  In order to achieve the above object, the invention according to claim 7 is the fundus camera according to claim 6, wherein the number of flash light emissions from the start of the initial shooting time indicated by the initial shooting time information is calculated. Counting means for counting and generating the number of times of light emission, and time counting means for measuring the elapsed time from the start of the initial photographing time and generating the elapsed time information, the light emission number calculating means, At the time of the elapsed time measured by the time measuring means, the charge amount indicated by the discharge amount information is multiplied by the number of times of light emission counted by the counting means to calculate the consumed charge amount up to the elapsed time, and the charging speed The charge rate indicated by the information is multiplied by the elapsed time to calculate the charge amount up to the elapsed time, and the consumed charge amount is subtracted from the maximum charge amount indicated by the maximum charge amount information. In both cases, by adding the charge amount, the remaining charge amount of the capacitor at the elapsed time is calculated, and the remaining charge amount is divided by the charge amount indicated by the discharge amount information to obtain the number of flash light emission possible times. It is characterized by calculating.

  In order to achieve the above object, the invention according to claim 8 is the fundus camera according to claim 6 or 7, wherein the exposure amount when the fundus is photographed with fluorescence is automatically set. And an exposure amount automatic setting means for discharging the capacitor so as to emit flash light according to the exposure amount, wherein the light emission number calculating means corresponds to the exposure amount set by the exposure amount automatic setting means. The number of times flash light can be emitted during the initial photographing time is calculated using the discharge amount of the capacitor as the discharge amount information.

  In order to achieve the above object, the invention described in claim 9 is the fundus camera according to claim 6 or 7, further comprising exposure amount detection means for detecting an exposure amount of flash light. The light emission number calculating means calculates the number of times the flash light can be emitted during the initial photographing time using the discharge amount of the capacitor corresponding to the exposure amount detected by the exposure amount detecting means as the discharge amount information. Features.

  In order to achieve the above object, the invention according to claim 10 is the fundus camera according to claim 6 or 7, wherein the exposure amount when the fundus is photographed with fluorescence is set. An exposure amount setting operation means for accepting an operation is further provided, wherein the light emission number calculating means calculates the discharge amount of the capacitor corresponding to the amount of flash light according to the exposure amount set by the exposure amount setting operation means. The amount of flash light that can be emitted during the initial photographing time is calculated as the amount information.

  In order to achieve the above object, the invention according to claim 11 is the fundus camera according to any one of claims 6 to 10, wherein the photographing time setting means is the initial photographing. It is possible to set medium period shooting time information indicating a medium period shooting time after the passage of the initial shooting time indicated by the time information, and the light emission number calculating means indicates the medium period shooting time information set by the shooting time setting means. The number of times the flash light can be emitted during the medium period shooting time is calculated.

  In order to achieve the above object, the invention according to claim 12 is the fundus camera according to claim 11, wherein the photographing time setting means is configured so that the medium-term photographing time indicated by the medium-term photographing time information has elapsed. Late shooting time information indicating the latter shooting time can be set, and the number of flashes calculating means can emit flash light at the latter shooting time indicated by the latter shooting time information set by the shooting time setting means. Is calculated.

  In order to achieve the above object, a thirteenth aspect of the present invention is the fundus camera according to any one of the sixth to twelfth aspects, wherein the flash light after the initial photographing time has elapsed. And a control means for controlling the discharge of the capacitor so as to increase the amount of the light of the first imaging time more than that during the initial photographing time.

  In order to achieve the above object, the invention described in claim 14 is the fundus camera according to any one of claims 1 to 13, wherein the charging means is configured to start shooting from the start of shooting. Until this time, the capacitor is always charged.

  According to the present invention, it is possible to calculate the number of flashlights that can be emitted, and thus it is possible to obtain the number of images that can be shot during continuous shooting.

  An example of a preferred embodiment of a fundus camera according to the present invention will be described in detail with reference to the drawings as appropriate. Hereinafter, the main embodiment according to the present invention will be described first, and embodiments having different control contents will be described. Note that these embodiments are not independent of each other, and it is also possible to configure a fundus camera having the contents of a plurality of embodiments.

  The fundus camera according to the present invention has a configuration for suitably performing continuous photographing in fluorescent fundus photographing by adjusting the discharge of the capacitor to control the state of continuous flash light. In particular, the objective is to suitably perform imaging at the initial imaging time including the time when the fluorescent agent intravenously injected into the examiner flows into the fundus blood vessel, and the maximum charge amount stored in the capacitor and the flash light are unified. The number of times of flash light emission can be calculated based on the amount of electric charge discharged from the capacitor to regenerate and the speed at which the charging means charges the capacitor.

  The initial imaging time is usually about 30 seconds after the fluorescent agent starts flowing into the fundus blood vessel (that is, from the start of imaging). In the initial shooting time, taking into consideration the burden on the subject due to glare, it is normal to repeat the continuous shooting for several seconds and the shooting pause for several seconds. During continuous imaging, it is preferable to capture as many images as possible in order to capture the state of the fundus blood vessel in more detail. In the middle and late shooting times after the initial shooting time has elapsed, continuous shooting at a speed as high as the initial shooting time is not required. In addition, at the initial imaging time, the amount of exposure does not have to be very large because the blood concentration of the fluorescent agent is high. However, a relatively large exposure is required at the middle and late imaging times when the blood concentration decreases over time. A quantity is needed. Thus, in fluorescent fundus photographing, it is preferable to shift the photographing form in accordance with the passage of photographing time. The fundus camera of the present invention has the following configuration in order to satisfy such a requirement.

[Configuration of optical system]
First, the configuration of the optical system provided in the fundus camera 1 of the present embodiment will be described. FIG. 1 is a schematic side view showing an optical system of the fundus camera 1. A TV camera 20 </ b> A and a (35 mm) film camera 20 </ b> B as imaging means for photographing the fundus oculi Ef of the eye E are detachably connected to the housing 1 </ b> A of the fundus camera 1. An image photographed by the TV camera 20A is displayed on a monitor device (not shown). In the housing 1A, an illumination optical system 10 for irradiating illumination light to the fundus oculi Ef, and a photographing optical system 20 for capturing fundus images by receiving the fundus reflection light of the illumination light and fluorescence emitted from the fundus It has. The photographing optical system 20 also serves as an observation optical system for the examiner to observe the fundus oculi Ef.

[Illumination optics]
The illumination optical system 10 includes a stationary light source 11 for emitting steady light, a condenser lens 12 for condensing the light emitted from the stationary light source 11, a flash light source 13 for emitting flash light, and the flash light source 13 A condenser lens 14 that condenses the emitted light, an exciter filter 15 for fluorescence photography, an illumination diaphragm 16, a relay lens 17, a reflection mirror 18, and a relay lens group 19 are provided.

  The exciter filter 15 is driven by driving means such as a solenoid, and can be inserted into and removed from the optical axis (illumination optical axis) O1 of the illumination optical system 10. Other optical elements are disposed on the illumination optical axis O1.

  The stationary light source 11 is composed of a halogen lamp or the like, and is lit when observing the fundus oculi Ef or shooting a moving image of the fundus oculi Ef. The flash light source 13 is composed of a xenon lamp or the like, and emits flash light when the fundus oculi Ef is photographed with the film camera 20B or when the fundus oculi Ef is photographed with fluorescence. The flash light source 13 is configured to emit flash light by discharging a capacitor C described later.

  The exciter filter (excitation filter) 15 transmits infrared light having a wavelength in the vicinity of 780 nm, which is a peak wavelength absorbed by ICG (Indocyanine Green; a special dye for fluorescence photography), for example, and a longer wavelength. It is a filter that cuts out light.

  The illumination stop 16 is disposed in a conjugate manner with the anterior segment of the eye E. An annular slit (ring slit) is formed in the illumination stop 16 coaxially with the illumination optical axis O1, and is used to convert light from the steady light source 11 and the flash light source 13 into a light beam having a cross-sectional ring shape. Is. In this ring shape, reflected light and fluorescence from the fundus oculi Ef are emitted from the eye E through the ring-shaped central region, and the reflected light and fluorescence are separated from the illumination light, so that the captured image has an influence of the illumination light. This is to prevent intervention.

[Photographing optical system]
The photographing optical system 20 includes an optical element for photographing a fundus image by guiding a light beam from the fundus oculi Ef of the eye E to the TV camera 20A or the film camera 20B. The photographing optical system 20 includes an objective lens 21 arranged facing the eye E, a perforated mirror 22, a focusing lens 23 for focusing, and a light beam from the fundus oculi Ef as a film of the film camera 20B. Imaging lenses 24 and 26 that form an image on the imaging surface (not shown), the optical element 25 for fluorescent photographing, and a quick return for switching between photographing with the TV camera 20A or photographing with the film camera 20B. Photographed with a mirror 27, a field lens 28, a reflection mirror 29, an imaging lens 30 that forms an image of a light beam from the fundus oculi Ef on an imaging surface (not shown) of the imaging device of the TV camera 20A, and the TV camera 20A. A quick return mirror 31 for switching between performing the observation and observing the fundus oculi Ef, and an eyepiece that faces the eye E 'of the examiner Figure 32 and are provided.

  The perforated mirror 22 is arranged at a position conjugate with the pupil of the eye E to be examined. Further, the perforated mirror 22 is obliquely arranged on the photographing optical axis O2 so as to synthesize the illumination optical axis O1 and the photographing optical axis O2. An opening 22 a is formed at the center of the perforated mirror 22. Illumination light from the illumination optical system 10 is reflected in the direction of the eye E by the perforated mirror 22. On the other hand, the light flux from the fundus oculi Ef is guided to the TV camera 20A and the film camera 20B through the opening 22a of the perforated mirror 22.

  The focusing lens 23 is moved in a direction parallel to the optical axis (photographing optical axis) O2 of the photographing optical system 20 by driving means such as a pulse motor.

  The imaging lens 24 and the fluorescence imaging optical element 25 are driven by driving means such as a solenoid and are selectively disposed on the imaging optical axis O2. The imaging lens 24 is disposed on the photographing optical axis O2 when observing the fundus or photographing with the film camera 20B. Further, the fluorescence imaging optical element 25 is disposed on the imaging optical axis O2 during fluorescence imaging.

  The fluorescence imaging optical element 25 is configured by bonding a lens 25a and a barrier filter 25b. The barrier filter 25b transmits light having a wavelength in the vicinity of 820 nm, which is the peak wavelength of infrared fluorescence emitted when the ICG absorbs infrared light having a wavelength of 780 nm, and cuts light having a shorter wavelength than that. It is a filter to do.

  The quick return mirrors 27 and 31 are configured to be rotatable about one end thereof, and are rotated in the direction of the arrow shown in FIG. 1 by the driving means.

  In addition, a further exciter filter (referred to as a second exciter filter) that can be selectively arranged with the exciter filter 15 is provided on the illumination optical axis O1, and in addition to the fluorescence imaging optical element 25, further fluorescence imaging optics. The element (including the second barrier filter) may be configured to be selectively arranged on the photographing optical axis O2. In that case, as the second exciter filter, a filter that transmits infrared light having a wavelength in the vicinity of 805 nm, which is a peak wavelength absorbed by ICG combined with albumin, and cuts light having a longer wavelength is used. In addition, the second barrier filter transmits light having a wavelength in the vicinity of 835 nm, which is the peak wavelength of infrared fluorescence emitted when ICG combined with albumin absorbs infrared light having a wavelength of 805 nm, and A filter that cuts light having a shorter wavelength than that is used. Thereby, the exciter filter 15 is made to correspond to the change in the wavelength of the fluorescence accompanying the change in the absorption wavelength when the albumin in the blood and ICG are combined with the passage of time after the intravenous injection of the fluorescent agent. It can be changed to an exciter filter, and the barrier filter 25b can be changed to a second barrier filter (see Japanese Patent Application Laid-Open No. 8-173389 by the present applicant).

[Control system configuration]
A control system provided in the fundus camera 1 will be described with reference to the block diagram shown in FIG. The control system of the fundus camera 1 is mainly configured by a personal computer connected to the fundus camera 1. Various operations of the fundus camera 1 are controlled in accordance with signals from a control unit 100 including an arithmetic control device such as a CPU of the computer. In particular, the control means 100 controls processing according to the present invention by executing a control program stored in advance in a ROM, hard disk drive or the like (storage means 101) not shown.

  The control system of the fundus camera 1 includes the control unit 100, the storage unit 101, the photographing time setting unit 102, the light emission number calculation unit 103, the operation unit 104, the time measuring unit 105, the counting unit 106, Display means 107 is provided.

  The control means 100 is connected to a capacitor C that supplies a voltage for operating the flash light source 13 and a charging means B that charges the capacitor C. The control means 100 controls the light amount and timing of the flash light emitted from the flash light source 13 by controlling the discharge amount and discharge timing of the capacitor C. Further, the control unit 100 controls the charging of the capacitor C by controlling the charging unit B to adjust the voltage applied to the capacitor C. In the present embodiment, the charging means B is controlled so that the capacitor C is always charged at a predetermined charging speed. Note that “always” means that the capacitor C is charged at the predetermined charging rate even during discharge of the capacitor C, that is, during the flash light emission.

  Although not shown, the control means 100 includes a drive means for driving the exciter filter 15, a drive means for driving the imaging lens 24 and the fluorescence imaging optical element 25, a power supply circuit for supplying power to the stationary light source 11, a quick Various components related to the optical system of the fundus camera 1 such as the return mirrors 27 and 31 are appropriately connected. Similarly, although not shown, the control unit 100 also controls other units of the control system shown in FIG.

  The storage unit 101 includes a storage device such as a RAM, a ROM, and a hard disk drive, and stores the control program and various data related to the control. The storage means 101 stores, in particular, maximum charge amount information 101a, discharge amount information 101b, and charge rate information 101c.

  The maximum charge amount information 101a is information indicating the maximum charge amount (Q) that can be stored in the capacitor C, that is, the accumulated charge amount in the fully charged state of the capacitor C. Note that the control means 100 controls the charging means B before photographing with the fundus camera 1 to fully charge the capacitor C.

  The discharge amount information 101b is information indicating the amount of charge (Q1) discharged from the capacitor C in order for the flash light source 13 to emit flash light once. The discharge charge amount (Q1) is related to the exposure amount of the flash light. However, in continuous photographing in fluorescent fundus photographing, the flash light is continuously emitted with a constant exposure amount. It becomes a constant value.

  The charging speed information 101c indicates the speed at which the charging means B charges the capacitor C, that is, the predetermined charging speed (v). The maximum charge amount information 101a and the charging speed information 101c are input in advance based on the design information of the capacitor C and the charging unit B and stored in the storage unit 101.

  The imaging time setting means 102 is used for the user to input initial imaging time information 102a indicating initial imaging time (T) including the time when the fluorescent agent intravenously injected into the subject flows into the blood vessel of the fundus oculi Ef. For example, it is comprised from input devices, such as a keyboard and a mouse | mouth of the said computer.

  The operation means 104 is composed of, for example, a release button connected to the fundus camera 1. The examiner takes a picture by pressing the release button. The examiner can perform continuous shooting by continuously pressing the release button. Shooting stops when you release the release button.

  The time measuring means 105 is constituted by, for example, a CPU timer, and generates elapsed time information indicating an elapsed time from the start of photographing. The time measuring means 105 starts time measurement in response to the operation of the operation means 104.

  The counting means 106 counts the number of times the flash light has been emitted, and generates light emission number information indicating the number of times the flash light has been emitted since the start of photographing. The count means 106 is comprised by said CPU, for example. The counting means 106 starts a counting operation in response to the operation of the operating means 104, and counts the number of flash light emissions based on a signal for controlling the discharge of the capacitor C so that the control means 100 emits the flash light. .

  The number of times of light emission calculation 103 is a maximum charge amount (Q) indicated by the maximum charge amount information 101a stored in the storage means 101, a discharge amount (Q1) indicated by the discharge amount information 101b, and a charge rate indicated by the charge rate information 101c. Based on (v), the number of possible flashes (N) 103a of the flash light source 13 in the initial photographing time (T) is calculated. The light emission number calculation means 103 is composed of, for example, an arithmetic control device of the computer.

The light emission number calculating means 103 refers to the count result (n) of the number of light emission times by the counting means 106 and the elapsed time (s) by the time measuring means 105, and calculates the flashable light emission number 103a. Specifically, first, the amount of light emitted (Q1) indicated by the discharge amount information 101b is multiplied by the number of times of light emission (n) counted by the counting means 106, and the flash light from the start of photographing to the elapsed time (s). The amount of electric charge consumed by (the amount of electric charge consumed; Q ₋ = n × Q1) is calculated. Further, the charge rate (v) indicated by the charge rate information 101c is multiplied by the elapsed time (s), and the amount of charge charged in the capacitor C from the start of shooting to the elapsed time (s) (charge amount; Q ₊ = V × s). Next, the consumed charge amount (Q ₋ ) is subtracted from the maximum charge amount (Q) indicated by the maximum charge amount information 101a and the charged charge amount (Q ₊ ) is added to the capacitor C during the elapsed time (s). The remaining charge amount (residual charge amount; Q _S = Q−Q ₋ + Q ₊ ) is calculated. Then, by dividing the residual charge amount (Q _S ) by the discharge charge amount (Q 1) and adopting the integer part, the number of flash light emission possible times at the time of the elapsed time s (N = [Q _S / Q1]; where [X] is a so-called Gaussian symbol representing the maximum integer value not exceeding the number X).

  By the arithmetic processing by the light emission number calculating means 103 as described above, it is possible to determine how many times the flash light source 13 can emit light at an arbitrary elapsed time (s) by the time measuring means.

  In a rare case, in the case where continuous shooting is continuously performed through the initial shooting time (T), the number-of-flashes calculation unit 103 determines the flash light source 13 at the initial shooting time (T) in the following manner. The number of possible light emission (N) 103a can be calculated. First, the initial photographing time (T) is divided by an arbitrary number of times of light emission (n = 1, 2, 3,...), And the light emission interval (t = t ( n) = T / n) is calculated. Next, the calculated light emission interval (t) is multiplied by the charge rate (v), and the amount of charge with which the capacitor C is charged during this light emission interval (t) (charge amount; Q2 = t × v) Ask for. Here, since the light emission interval (t) of the flash light source 13 is the discharge time of the capacitor C, the charge amount (Q2) during this period is generally smaller than the discharge amount (Q1) during this period (Q2 <Q1). Further, the charge amount (Q2) of the capacitor C in the light emission interval (t) is subtracted from the discharge amount (Q1), and a decrease value (Q1-Q2> of the charge amount stored in the capacitor C in the light emission interval (t). 0). Subsequently, a value (Qn × (Q1−Q2) obtained by subtracting a value obtained by multiplying the charge amount decrease value (Q1−Q2) by the number of possible light emission (N) from the maximum charge amount (Q) of the capacitor C. )) And the discharge amount (Q1) are compared to determine whether or not Q−n × (Q1−Q2) <Q1. The above calculation is performed for an arbitrary number of possible flashes (N), and the smallest integer (N> 0) is calculated from the possible flashes (N) such that Qn × (Q1−Q2) <Q1. The integer (N) is set as the possible number of flashes (N) 103a of the flash light source 13 when continuous shooting is performed through the initial shooting time (T). Note that the same calculation is performed in ascending order of the number of light emission times n = 1, n = 2, n = 3,..., And for each n, it is sequentially determined whether Qn × (Q1−Q2) ≧ Q1. Thus, the target integer number N of times of light emission may be set to an integer n that first satisfies Qn × (Q1−Q2) <Q1. In this way, it is possible to always obtain the number of possible flashes (N) 103a of the flash light source 13 in the initial photographing time (T) with a finite amount of computation.

  The display means 107 is for displaying various images based on the control of the control means 101, and is composed of, for example, a monitor device connected to the computer. The display means 107 displays the flashable light emission count 103 a calculated by the light emission count calculation means 103.

  The display means 107 is controlled so as to reduce the number of possible flashes to be displayed in response to the flash light being emitted. Specifically, when the capacitor C is discharged once in order to emit flash light once, the control unit 100 decreases the number of possible light emission (for example, m) displayed on the display unit 107 by one time (that is, m). m-1 is displayed).

  Similarly, the display unit 107 is controlled so as to increase the number of times that light can be displayed according to the charging of the capacitor C by the charging unit B. Specifically, when the discharge charge amount (Q1) for one flash light indicated by the discharge amount information 101b is charged in the capacitor C, the control unit 100 displays the possible number of times of light emission (for example, m) displayed on the display unit 107. Is increased by one time (that is, m + 1 is displayed). Note that, as described above, since the charging unit B is constantly charging the capacitor C at a constant charging rate (v), the control unit 100 displays the number of times that light can be emitted every certain time (Q1 / v). It is supposed to increase.

  In addition, it is not necessary to increase / decrease the light emission possible number displayed on the display unit 107 by one time as described above, and it may be configured to increase / decrease a plurality of times at once, for example, three times.

  Although not shown, each piece of information set or calculated by each of the above means is stored in the storage means 101. The control unit 100 can access these pieces of information stored in the storage unit 101. Similarly, although not shown, the control unit 100 can acquire the elapsed time by the time measuring unit 105.

[Processing procedure]
An example of a processing procedure executed by the fundus camera 1 having the above configuration will be described with reference to flowcharts shown in FIGS. FIG. 3 and FIG. 4 show the fluorescence imaging processing procedure during the initial imaging time.

  In advance, the storage unit 101 stores maximum charge amount information 101a, discharge amount information 101b, and charge rate information 101c. In order to perform fluorescence imaging of the fundus oculi Ef of the eye E, when the fundus camera 1 is set to the fluorescence imaging mode by a predetermined operation, the control unit 100 arranges the exciter filter 15 on the illumination optical axis O1 and performs fluorescence imaging. The optical element 25 is arranged on the photographing optical axis O2, and the quick return mirrors 27 and 31 are arranged at the positions shown in FIG. Note that the fundus camera 1 is already aligned with the eye E.

  The control unit 100 controls the charging unit B to apply a voltage to the capacitor C so that the capacitor C is fully charged (S1). Here, in response to the capacitor C being in a fully charged state, the fundus camera 1 may display a message image indicating that fluorescence imaging can be started, turn on the pilot lamp, or output audio. .

  When the initial shooting time information 102a is set from the shooting time setting means 102 (S2), the light emission number calculation means 103 causes the maximum charge amount indicated by the maximum charge amount information 101a stored in the storage means 101 and the discharge amount information. Based on the discharge amount indicated by 101b and the charge rate indicated by the charge rate information 101c, the flashable number of times 103a of the flash light source 13 in the initial photographing time is calculated (S3). Specifically, by dividing the maximum amount of charge accumulated in the capacitor C in a fully charged state by the amount of discharge for one flash light, the number of possible light emission 103a at the beginning of photographing is calculated. The calculated possible number of times of light emission is displayed on the display means 107 by the control means 100 (S4).

  When the examiner presses the release button as the operation means 104 to start photographing at the initial photographing time (S5), the time counting means 105 starts time counting, and the counting means 106 starts counting the number of times of flash light emission ( S6).

  The examiner holds the release button, which is the operation means 104, in a pressed state, and continuously photographs the fundus oculi Ef for several seconds. During the continuous photographing, the control unit 100 controls the charging and discharging of the capacitor C, and continuously flashes the flash light from the flash light source 13 while charging the capacitor C with the charging unit B. The control means 100 changes the possible number of times of light emission displayed on the display means 107 according to the control of charging and discharging of the capacitor C (S7). At this time, since the discharge amount per unit time is generally larger than the charge amount, the possible number of times of light emission displayed on the display means 107 is decreased.

  When the examiner releases the release button, which is the operation means 104, and stops continuous shooting (S8), the counting means 106 stops counting the number of flash light emissions based on the signal from the control means 100 (S9). ). The light emission number calculation means 103a corresponds to this light emission number based on the light emission number counted until the stop of the continuous shooting by the counting means 106 and the discharge amount indicated by the discharge amount information 101b stored in the storage means 101. The above-mentioned consumed electric charge amount of the capacitor C to be calculated is calculated (S10).

  When the examiner presses the release button as the operation means 104 and resumes continuous shooting (S11), the counting means 106 resumes counting the number of flash light emissions (S12).

  The number-of-lights-emission calculating means 103a is based on the elapsed time from the start of photographing by the time measuring means 105 until the resumption of photographing and the charging speed indicated by the charging speed information 101c stored in the storage means 101. The above-mentioned charge amount is calculated (S13). Further, the light emission number calculating means 103a is based on the maximum charge amount indicated by the maximum charge amount information 101a stored in the storage means 101, the charged charge amount calculated in step S13, and the consumed charge amount calculated in step S10. Then, the number of possible flashes 103a at the time of resuming the shooting in step S11 is calculated (S14).

  Similarly to step S7, the control means 100 changes the possible number of times of light emission displayed on the display means 107 according to the control of charging and discharging of the capacitor C (S15).

  When the examiner releases the release button, which is the operation means 104, and stops continuous shooting again (S16), the counting means 106 stops counting the number of flash light emissions based on the signal from the control means 100 (S16). S17). The number-of-lights-emission calculating unit 103a includes the number of times of light-emission counted by the counting unit 106 between the start of shooting (step S5) and the stop of continuous shooting again (step S16), and the discharge amount information 101b stored in the storage unit 101. Is calculated based on the discharge amount indicated by (S18).

  The control means 100 acquires the elapsed time by the time measuring means 105 until the second photographing stop shown in step S16, and compares this elapsed time with the initial photographing time indicated by the initial photographing time information 102a to obtain the initial photographing time. It is determined whether or not has been completed (S19).

  If the initial shooting time has not ended (S19; N), the process stands by until continuous shooting is resumed, and at the same time, the processing from step S11 to step S18 is performed. This process is repeated until the end of the initial shooting time (S20).

  After the initial imaging time, the fundus oculi Ef is fluorescently imaged according to the imaging method shown in other control modes described later, the imaging method determined by the user, or the like.

[Action / Effect]
According to such a fundus camera 1, the number of flash light emissions that can be made during the set initial shooting time, that is, the number of shots that can be taken, can be calculated, and shooting can be performed for the initial shooting time based on this. It is possible to take as many fundus images as possible within the time, and to examine the state of the blood vessels of the fundus oculi Ef in detail.

  In addition, since it is possible to calculate and display how many continuous shots can be taken at an arbitrary point in the initial shooting time, the examiner can refer to this display and make as many copies as possible. A fundus image can be taken. In particular, even during continuous shooting, it is possible to grasp how many more shots are possible, which is convenient for operation.

[Other control modes 1]
FIG. 5 shows a block diagram of another control mode of the fundus camera according to the present invention. The fundus camera of this control mode includes the same optical system as the above-described fundus camera 1. This fundus camera is characterized by a method of obtaining discharge amount information 101b used for calculating the number of possible flashes 103a of the flash light source 13 during the initial photographing time. In FIG. 5, the same components as those in the block diagram of FIG.

[Control system configuration]
The fundus camera of this control form includes a control unit 100, a storage unit 101, an imaging time setting unit 102, a light emission number calculation unit 103, a discharge amount calculation unit 110, an exposure amount detection unit 111, and an exposure amount setting operation unit 112. Has been. Although not shown, the operation unit 104, the time measuring unit 105, the counting unit 106, and the display unit 107 shown in FIG. 2 are provided.

  The control means 100 automatically sets the exposure amount of flash light emitted from the flash light source 13 when photographing the fundus oculi Ef, and controls the discharge of the capacitor C so as to emit flash light according to the set exposure amount. It operates as an exposure amount automatic setting means. That is, the control unit 100 controls a so-called auto exposure function. The control means 100 executes this auto exposure function according to a control program (not shown) stored in the storage means 101. The control means 100 sends the automatically set exposure amount data to the discharge amount calculation means 110.

  The discharge amount calculation means 110 is for calculating the discharge amount of the capacitor C according to the value of the exposure amount of the flash light from the flash light source 13, and is composed of, for example, the arithmetic control device of the computer. The discharge amount calculation means 110 includes an exposure amount-discharge amount table 110a that associates the exposure amount with the discharge amount. The exposure amount-discharge amount table 110 a is created in advance based on the characteristics of the capacitor C and the flash light source 13. As the creation method, for example, it is possible to measure the exposure amount of the flash light with respect to various discharge amounts of the capacitor C, and create the correspondence relationship in association with the table format. Further, the measurement result of the exposure amount may be interpolated by a mathematical process to be associated with the corresponding house Ow graph format.

  The exposure amount detection unit 111 is a light amount detection sensor for detecting the amount of flash light emitted from the flash light source 13, and is disposed at any position of the optical system such as the image pickup device of the TV camera 20A shown in FIG. Yes. The exposure amount detection unit 111 transmits the detection result to the discharge amount calculation unit 110.

  The exposure amount setting operation means 112 is used for performing a so-called manual exposure function, and is a means for receiving an operation for setting an exposure amount of flash light when the fundus oculi Ef is photographed with fluorescence. The exposure amount setting means 112 includes, for example, an input device such as a keyboard and a mouse of the computer described above, and an exposure amount setting button and dial provided on the fundus camera body. The exposure amount data set by the exposure amount setting operation unit 112 is transmitted to the discharge amount calculation unit 110.

[Processing procedure]
With reference to FIGS. 6, 7, and 8, an example of a procedure of processing executed by the fundus camera of the control form will be described. FIG. 6 is a flowchart showing a processing procedure when the auto exposure function is used, that is, when the control unit 100 automatically sets the exposure amount of the flash light. FIG. 7 is a flowchart showing a processing procedure when the exposure amount detection result by the exposure amount detection means 111 is used. FIG. 8 is a flowchart showing a processing procedure when the manual exposure function is used, that is, when the exposure amount is set manually by the exposure amount setting means 112.

  In order to execute the processing of this control mode described below, the maximum charge amount information 101a and the charging speed information 101b are stored in the storage unit 101 in advance. In addition, it is assumed that preliminary processing such as setting and alignment of the fluorescence imaging mode has already been performed, and the capacitor is in a fully charged state.

(Processing procedure when using the auto exposure function)
First, the user sets the initial shooting time information 102a by the shooting time setting means 102 (S31). The control means 100 automatically sets the exposure amount of the flash light from the flash light source 13, and transmits this exposure amount value to the discharge amount calculation means 110 (S32). The discharge amount calculating means 110 refers to the exposure amount-discharge amount table 110a, calculates the discharge amount value of the capacitor C corresponding to the exposure amount value received from the control means 100, and sends it to the storage means 101 (S33). ). The value of the discharge amount is stored in the storage unit 101 as discharge amount information 101b.

  The light emission number calculation means 103 is based on the maximum charge amount information 101a and the charge speed information 101c stored in advance in the storage means 101, and the discharge amount information 101b calculated by the discharge amount calculation means 110. The number of possible flashes 103a of the flash light source 13 is calculated (S34). The calculation method is the above-described method by the light emission number calculation means 103. The subsequent processing is the same as the processing after step S4 in the flowchart shown in FIG.

(Processing procedure when detecting exposure)
First, the user sets initial shooting time information 102a by the shooting time setting means 102 (S41). The control means 100 controls the discharge of the capacitor C to emit flash light from the flash light source 13 (S42). The exposure amount detection unit 111 detects the exposure amount of the flash light, and transmits the detection result to the discharge amount calculation unit 110 (S43). The discharge amount calculation means 110 calculates the discharge amount value of the capacitor C corresponding to the exposure amount value received from the exposure amount detection means 111 with reference to the exposure amount-discharge amount table 110 a and sends it to the storage means 101. (S44). The value of the discharge amount from the discharge amount calculation means 110 is stored in the storage means 101 as discharge amount information 101b.

  The light emission number calculation means 103 is based on the maximum charge amount information 101a and the charge speed information 101c stored in advance in the storage means 101, and the discharge amount information 101b calculated by the discharge amount calculation means 110. The number of possible flashes 103a of the flash light source 13 is calculated (S45). The subsequent processing is the same as the processing after step S4 in the flowchart shown in FIG.

(Processing procedure when using the manual exposure function)
First, the user sets initial shooting time information 102a by the shooting time setting means 102 (S51). The user operates the exposure amount setting operation unit 112 to manually set the exposure amount of the flash light from the flash light source 13 (S52). The set exposure value is transmitted to the discharge amount calculation means 110. The discharge amount calculation unit 110 refers to the exposure amount-discharge amount table 110a, calculates a discharge amount value of the capacitor C corresponding to the exposure amount value received from the exposure amount setting operation unit 112, and stores the value in the storage unit 101. Send (S53). The value of the discharge amount is stored in the storage unit 101 as discharge amount information 101b.

  The light emission number calculation means 103 is based on the maximum charge amount information 101a and the charge speed information 101c stored in advance in the storage means 101, and the discharge amount information 101b calculated by the discharge amount calculation means 110. The number of possible flashes 103a of the flash light source 13 is calculated (S54). The subsequent processing is the same as the processing after step S4 in the flowchart shown in FIG.

[Action / Effect]
According to the fundus camera of this control mode, it is possible to set or detect the exposure amount of the flash light and calculate the number of possible flashes corresponding to the exposure amount. Shooting at the initial shooting time can be performed by the number of times.

[Other control modes 2]
FIG. 9 shows a block diagram of another control mode of the fundus camera according to the present invention. The fundus camera of this control mode includes the same optical system as the above-described fundus camera 1. This fundus camera relates to the control of continuous shooting in the stage after the elapse of the initial shooting time, that is, in the middle and late stages of the shooting time.

  The fundus camera of this control form is similar to the fundus camera 1 shown in FIG. 2, the control unit 100, the storage unit 101, the photographing time setting unit 102, the light emission number calculation unit 103, the operation unit 104, the time measuring unit 105, and the counting unit. 106 and the display means 107 are comprised.

  In addition to the setting of the initial shooting time information 102a indicating the initial shooting time, the shooting time setting means 102 sets the medium-term shooting time information 102b indicating the medium-term shooting time after the elapse of the initial shooting time and the elapse of this medium-time shooting time. And late-stage shooting time information 102c indicating the latter-stage shooting time from the end of shooting to the end of shooting. The set initial photographing time information 102a, middle term photographing time information 102b, and latter term photographing time information 102c are transmitted to the light emission number calculating means 103, respectively.

  The number-of-emissions calculation unit 103a can emit flash light at the initial shooting time indicated by the initial shooting time information 102a set by the shooting time setting unit 102 and at the intermediate shooting time indicated by the intermediate shooting time information 102b. The number of times the flash light can be emitted in the later photographing time indicated by the number of times and the latter photographing time information 102c is calculated to obtain the possible number of times 103a.

  By the way, at the initial imaging time, the amount of the flash light is small because the concentration of the fluorescent agent in the blood is high. On the other hand, a large number of captured images are acquired to capture in detail the state in which the fluorescent agent flows into the fundus blood vessel. There is a need to. Further, during the middle and late photographing times, a large amount of flash light is required as the blood concentration of the fluorescent agent gradually decreases. On the other hand, since the photographed image does not change much, the number of photographed images can be reduced.

  In order to cope with such a condition, a program for controlling the light emission of the flash light source 13 so as to increase the light emission interval while reducing the exposure amount of the flash light as the photographing time elapses is created, and the control means 100 can automatically control the discharge of the capacitor C.

  For example, when the total shooting time is 5 minutes, the initial shooting time is 30 seconds, the middle shooting time is 2 minutes 30 seconds from 30 seconds to 3 minutes, and the latter shooting time is 2 minutes from 3 minutes to 5 minutes. The flash light intensity for 3 minutes from the beginning is 18 watts, the light intensity after that is 25 watts, the continuous shooting interval of the initial shooting time is once per second, and the continuous shooting interval of the medium shooting time is 0.5 times per second. It is possible to use a control program that sets the continuous shooting interval of the late shooting time to 0.25 times per second.

  In addition, the continuous shooting may be stopped at a predetermined stage of shooting, for example, at the end of the initial shooting time, and in subsequent stages, the examiner may press the frame-by-frame release button for shooting.

  The control unit 100 refers to the elapsed time by the time measuring unit 105 to detect a transition from the initial shooting time to the middle shooting time and a shift from the middle shooting time to the later shooting time.

  According to such a fundus camera of this control mode, it is possible to perform appropriate photographing in response to the transition from the initial stage, the middle period, and the latter stage.

[Other control modes 3]
FIG. 10 shows a block diagram of a control mode that can be employed in the fundus camera according to the present invention. The fundus camera of this control mode includes the same optical system as the above-described fundus camera 1. This fundus camera has a structure for preventing excessive damage to the eye E by continuous flash light. In FIG. 10, the same components as those in the block diagram of FIG.

  The fundus camera in this control form includes a control unit 100, a storage unit 101, an imaging time setting unit 102, a light emission number calculation unit 103, a cumulative light amount calculation unit 121, a cumulative light amount determination unit 122, and a notification unit 200. . Although not shown, the operation unit 104, the time measuring unit 105, the counting unit 106, and the display unit 107 shown in FIG. 2 are provided.

  The storage unit 101 stores light amount information 101d and accumulated allowable light amount information 101e in addition to the maximum charge amount information 101a, the discharge charge amount information 101b, and the charging speed information 101c. The light amount information 101 d is information indicating the amount of light for one flash light emitted from the flash light source 13. The cumulative allowable light amount information 101e is information indicating a cumulative light amount (referred to as a cumulative allowable light amount) that can ensure the safety of the eye E when the flash light is continuously emitted. The light amount information 101d and the cumulative allowable light amount information 101e are set and input using an input device such as a keyboard of the computer and stored in the storage unit 101.

  The accumulated light quantity calculation means 121 uses the light quantity information 101d stored in the storage means 101, and the accumulated light quantity received by the eye E when the flash light is continuously emitted by the number of possible emission times 103a calculated by the light emission number calculation means 103. Is calculated. Specifically, the accumulated light amount is calculated by multiplying the light amount of one flash light amount indicated by the light amount information 101a by the number of possible flashes 103a.

  The accumulated light amount judging unit 122 compares the accumulated light amount calculated by the accumulated light amount calculating unit 121 (referred to as “calculated accumulated light amount”) with the accumulated allowable light amount indicated by the accumulated allowable light amount information 101e stored in the storage unit 101, and It is determined whether the calculated accumulated light quantity does not exceed the accumulated allowable light quantity.

  The control unit 100 controls the flash light from the flash light source 13 according to the determination result of the accumulated light amount determination unit 122. When receiving the determination result that the calculated accumulated light amount is less than or equal to the accumulated allowable light amount, the control unit 100 determines that the flash light source 13 can emit light with the light amount indicated by the light amount information 101e 103a. The number of possible flashes 103a is displayed.

  When the calculated accumulated light quantity exceeds the accumulated allowable light quantity, the control unit 100 performs one of the following two controls. One of these two types of control modes can be selected by the user. The selection method is performed by an input device such as a keyboard of the computer.

  In the first control mode, control is performed so as to reduce the light amount of the flash light so that the cumulative light amount for the eye E does not exceed the cumulative allowable light amount. For this purpose, the control means 100 calculates the allowable light quantity for each flash light, for example, by dividing the cumulative allowable light quantity by the possible number of times of light emission 103a, and the flash light with this light quantity or a light quantity less than that light quantity. The discharge of the capacitor C is controlled so that is emitted. Note that the flash light does not need to have the same light amount, and even when the light amount is increased as the photographing time elapses, the calculation may be performed so that the accumulated light amount becomes smaller than the accumulated allowable light amount. In addition, the control unit 100 causes the display unit 107 to display the possible light emission number 103a. This first control mode is convenient when the light quantity of each flash light indicated in the light quantity information 101d exceeds the light quantity necessary for shooting, or when it is desired to acquire as many shots as possible.

  In the second control mode, control is performed so as to reduce the number of flash light emissions in order that the cumulative light amount for the eye E does not exceed the cumulative allowable light amount. For this purpose, the control unit 100 calculates the maximum number of times of light emission allowed for the eye E by dividing the cumulative allowable light amount by the light amount of one flash light indicated by the light amount information 101d, for example. The display unit 107 displays the number of times of light emission. In the second control mode, when the amount of light cannot be reduced below the amount of each flash light indicated in the light amount information 101d, or when it is determined that the state of the fundus oculi Ef can be sufficiently recognized even if the number of shots is reduced. It is preferable to use for such as.

  When the calculated accumulated light amount exceeds the accumulated allowable light amount, the control unit 100 controls the notification unit 200 to notify the user. The notification unit 200 includes a speaker device that outputs sound, a monitor device that displays a warning message, and the like.

  According to the fundus camera of this control mode, it is possible to avoid a situation in which the eye E is excessively damaged by continuous shooting.

  The configuration described above is an example of a specific configuration of the fundus camera according to the present invention, and various modifications can be made within the scope of the gist of the present invention.

It is the side view which showed an example of schematic structure of the optical system of embodiment of the fundus camera which concerns on this invention. It is the block diagram which showed an example of schematic structure of the control system of embodiment of the fundus camera which concerns on this invention. It is the flowchart which showed an example of the process sequence performed by embodiment of the fundus camera which concerns on this invention. It is the flowchart which showed an example of the process sequence performed by embodiment of the fundus camera which concerns on this invention. It is the block diagram which showed an example of schematic structure of the control system of the other control form of the fundus camera which concerns on this invention. It is the flowchart which showed an example of the process sequence performed with the other control form of the fundus camera which concerns on this invention. It is the flowchart which showed an example of the process sequence performed with the other control form of the fundus camera which concerns on this invention. It is the flowchart which showed an example of the process sequence performed with the other control form of the fundus camera which concerns on this invention. It is the block diagram which showed an example of schematic structure of the control system of the other control form of the fundus camera which concerns on this invention. It is the block diagram which showed an example of schematic structure of the control system of the control form employable for the fundus camera which concerns on this invention.

Explanation of symbols

13 Flash light source 15 Exciter filter 20A TV camera 25 Fluorescent imaging optical element 25b Barrier filter 100 Control unit 101 Storage unit 101a Maximum charge amount information 101b Discharge amount information 101c Charging speed information 102 Shooting time setting unit 102a Initial shooting time information 102b Medium period shooting Time information 102c Late shooting time information 103 Number of times of light emission calculation 103a Number of times of light emission 104 Operation means 105 Timekeeping means 106 Count means 107 Display means C Capacitor B Charging means E Eye to be examined Ef Fundus

Claims (14)

A light source that discharges electric charge stored in the capacitor to emit flash light; and an exciter filter that transmits a specific wavelength region of the flash light from the light source. Illumination optical system to irradiate;
A shooting optical system that receives a flash light from the illumination optical system and transmits fluorescence emitted from the fundus, receives the fluorescence that has passed through the barrier filter, and captures a fundus image;
Charging means for charging the capacitor;
A fundus camera that performs flash photography of the fundus by continuously flashing light at a predetermined light emission interval,
Maximum charge amount information indicating the maximum amount of charge that can be stored in the capacitor, discharge amount information indicating the amount of charge discharged from the capacitor to emit flash light once, and the charging unit charges the capacitor On the basis of charging speed information indicating the speed to perform shooting, light emission count information indicating the number of flash light emissions from the start of shooting, and elapsed time information indicating the elapsed time from the start of shooting. Means for calculating the number of times of light emission for calculating the number of possible flashes;
A fundus camera characterized by comprising: The apparatus further comprises an operation means for the user to operate start and stop of continuous fundus shooting,
2. The fundus camera according to claim 1, wherein the number-of-light-emissions calculation unit calculates the number of times the flash light can be emitted at the time when the continuous shooting is started in response to the start of continuous shooting by the operation unit.   The fundus camera according to claim 1, further comprising display means for displaying the number of times the flash light can be emitted calculated by the light emission number calculating means.   4. The fundus camera according to claim 3, wherein the display means reduces the number of times that the light can be displayed according to light emission of flash light.   5. The fundus camera according to claim 3, wherein the display unit increases the displayable number of times of light emission in accordance with charging of the capacitor by the charging unit.   An imaging time setting means for setting and inputting initial imaging time information indicating an initial imaging time including a time when a fluorescent agent intravenously injected into a subject flows into a blood vessel of the fundus is provided. The fundus camera according to any one of claims 1 to 5. Counting means for counting the number of flash light emission times from the start of the initial shooting time indicated by the initial shooting time information to generate the light emission number information;
Time counting means for measuring the elapsed time from the start of the initial shooting time and generating the elapsed time information,
The light emission number calculating means multiplies the amount of electric charge indicated by the discharge amount information by the number of light emission counted by the counting means at the time of the elapsed time counted by the time measuring means, and consumes up to the elapsed time. The charge amount is calculated, the charge rate indicated by the charge rate information is multiplied by the elapsed time to calculate the charge amount up to the elapsed time, and the consumed charge amount is calculated from the maximum charge amount indicated by the maximum charge amount information. And calculating the remaining charge amount of the capacitor at the elapsed time and dividing the remaining charge amount by the charge amount indicated by the discharge amount information. The fundus camera according to claim 6, wherein the possible number of times is calculated. An exposure amount automatic setting unit that automatically sets an exposure amount when fluorescently photographing the fundus and discharges the capacitor so as to emit flash light corresponding to the exposure amount,
The light emission number calculating means calculates the number of times the flash light can be emitted during the initial photographing time using the discharge amount of the capacitor corresponding to the exposure amount set by the exposure amount automatic setting means as the discharge amount information. The fundus camera according to claim 6 or 7, wherein: Further comprising an exposure amount detecting means for detecting an exposure amount of flash light;
The light emission number calculating means calculates the number of times the flash light can be emitted during the initial photographing time, using the discharge amount of the capacitor corresponding to the exposure amount detected by the exposure amount detection means as the discharge amount information. The fundus camera according to claim 6 or 7. An exposure amount setting operation means for receiving an operation for setting an exposure amount when performing fluorescence imaging of the fundus;
The light emission number calculating means uses the discharge amount of the capacitor corresponding to the light amount of the flash light corresponding to the exposure amount set by the exposure amount setting operation means as the discharge amount information, and the flash light amount at the initial photographing time. The fundus camera according to claim 6 or 7, wherein the number of times that light can be emitted is calculated. The photographing time setting means can set medium-term photographing time information indicating a medium-term photographing time after an initial photographing time indicated by the initial photographing time information,
The light emission number calculating means calculates the number of times the flash light can be emitted in the medium term photographing time indicated by the medium term photographing time information set by the photographing time setting means.
The fundus camera according to any one of claims 6 to 10, wherein the fundus camera is any one of the above. The shooting time setting means can set late shooting time information indicating a late shooting time after elapse of a medium shooting time indicated by the medium shooting time information,
The light emission number calculating means calculates the number of times the flash light can be emitted at the later photographing time indicated by the latter photographing time information set by the photographing time setting means.
The fundus camera according to claim 11.   13. The control device according to claim 6, further comprising control means for controlling the discharge of the capacitor so that the amount of flash light after the initial photographing time elapses is larger than that during the initial photographing time. The fundus camera according to any one of the above. The fundus camera according to any one of claims 1 to 13, wherein the charging unit constantly charges the capacitor from the start of shooting to the end of shooting.

Images