JP3927803B2 - Lamp life expectancy calculator for endoscope - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an endoscope apparatus that supplies illumination light to observe the inside of a body or a tube.
[0002]
[Prior art]
In endoscopic observation, light from a light source unit is supplied to a distal end of an endoscope insertion portion inserted into the body or the like through a light guide, and an image of the distal end of the insertion portion is observed using this light as illumination light. Known light sources include xenon lamps, metal halide lamps, halogen lamps, and the like. Xenon lamps and metal halide lamps are superior in terms of performance as a light source, such as brightness, lifetime, and color temperature, but have a problem of high price. On the other hand, halogen lamps have the disadvantage that they have a short lifetime and a slightly low color temperature, but they are advantageous in that they are inexpensive, so they are often used as light sources for endoscopes.
[0003]
[Problems to be solved by the invention]
Halogen lamps reach the end of their lives as the filaments gradually evaporate and eventually break. Although the filament breaks suddenly, the time until the filament breaks is greatly influenced by the magnitude of the voltage supplied to the lamp. Therefore, it is difficult to predict when the lamp will turn off. If the lamp suddenly breaks during endoscopic observation, the examination and treatment must be interrupted and the lamp must be replaced, which hinders the examination and treatment.
[0004]
An object of the present invention is to accurately predict the remaining usable period of a light source used for endoscope illumination.
[0005]
[Means for Solving the Problems]
A lamp life expectancy calculation apparatus for an endoscope apparatus according to the present invention includes a lamp used as an illumination light source during endoscopic observation, a lamp power supply unit that supplies power to the lamp, and a lamp based on a lamp voltage applied to the lamp. And a lamp remaining life calculating means for calculating a lamp remaining life corresponding to the remaining usable period.
[0006]
The lamp life expectancy calculating means calculates the lamp life expectancy by subtracting a predetermined value corresponding to the lamp voltage every predetermined time from the index value set as the initial value when the lamp is replaced while the power is supplied to the lamp. It is preferable to provide a memory in which the correspondence between the voltage and the predetermined value is stored as a lookup table. This makes it possible to quickly calculate the lamp life expectancy with a simple configuration.
[0007]
In addition, in order to calculate the lamp life expectancy with a simple method, the ratio between the first predetermined value corresponding to the first lamp voltage and the second predetermined value corresponding to the second lamp voltage is: The lamp life is preferably equal to the ratio of the lamp life when driven at a lamp voltage of 2 and the lamp life when driven at a first lamp voltage.
[0008]
The lamp life expectancy calculating means preferably comprises lamp life expectancy notifying means for notifying information related to the lamp life expectancy based on the lamp life expectancy calculated by the lamp life expectancy calculating means, and the lamp life expectancy notifying means is a lamp for displaying the lamp life expectancy. It is preferable to provide a life expectancy display means. For example, in order to make it possible to easily recognize the lamp life expectancy visually and sensuously, the lamp life expectancy display means displays the lamp life expectancy graphically. This makes it possible to visually and sensibly grasp the lamp life expectancy with a simple configuration.
[0009]
The lamp life expectancy calculating device further includes means for detecting the brightness of the image, level setting means for setting the reference level of the brightness of the image, and lamp voltage control means for controlling the lamp voltage in the lamp power supply unit. The voltage control means preferably controls the lamp voltage so as to maintain the image brightness at the reference level based on the information on the image brightness obtained by the means for detecting the image brightness. This makes it possible to always maintain the brightness of the image at an appropriate level. In the case where the endoscope is an electronic endoscope provided with an imaging device, it is preferable that the means for detecting the brightness of the image detects the brightness of the image based on the video signal of the image captured by the imaging device. . Accordingly, it is not necessary to provide a new detection device, and the brightness of the image can be automatically adjusted with a simple configuration and low cost.
[0010]
In the lamp voltage control means, the lamp voltage is preferably driven below the rated voltage. As a result, the lamp can be used for a period longer than the rated life, and the running cost can be reduced.
[0011]
In addition, an electronic endoscope apparatus according to the present invention includes a video signal processing apparatus provided with the lamp life expectancy calculating apparatus described above.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram schematically showing the configuration of an electronic endoscope apparatus according to an embodiment of the present invention.
[0013]
The electronic endoscope apparatus according to the present embodiment is roughly composed of an electronic endoscope (electronic scope) 10, a video signal processing apparatus (processor) 20, and a TV monitor 30. The electronic scope 10 is detachably connected to the processor 20, and the TV monitor 30 is connected to a video output terminal of the processor 20 through a video signal cable. In the present embodiment, only the TV monitor 30 is shown as a peripheral device, but peripheral devices such as a video printer, a VCR, and a computer may be connected simultaneously.
[0014]
The electronic scope 10 includes an elongated and flexible insertion portion, and an image pickup device (for example, CCD) 11 is provided at the tip thereof. The image pickup device 11 is a video signal processing circuit 21 provided in the processor 20. It is connected to the. The electronic scope 10 is provided with a light guide 12 formed of a bundle of ultrafine optical fibers, and the light guide 12 is optically connected to a light source unit 40 provided in the processor 20.
[0015]
The image sensor 11 is controlled based on a drive signal from the video signal processing circuit 21 and captures an image of the subject S using light transmitted from the light source unit 40 via the light guide 12 as illumination light. The image picked up by the image pickup device 11 is sent to the video signal processing circuit 21 as a video signal, subjected to signal processing such as blanking, clamping, white balance, and gamma correction, which has been conventionally known. A conforming video signal is output to the TV monitor 30 and displayed on the screen of the TV monitor 30. The video signal processing circuit 21 is connected to the system control circuit 22, and the operation of the video signal processing circuit is controlled and monitored by the system control circuit 22.
[0016]
The light source unit 40 includes a lamp (for example, a halogen lamp) 41, a reflecting mirror 42, a lamp power supply control circuit 43, and a diaphragm device 44. The light emitted from the lamp 41 is reflected by, for example, a reflecting mirror 42 shaped like a paraboloid, and is condensed on the incident end face of the light guide 12 via the diaphragm device 44. Electric power is supplied to the lamp 41 from the lamp power supply control circuit 43, and the brightness thereof is achieved by controlling the voltage applied to the lamp 41 from the lamp power supply control circuit 43, for example. The lamp power control circuit 43 is connected to the system control circuit 22 and is driven and controlled based on a signal command from the system control circuit 22. A diaphragm device 44 provided on the optical path between the lamp 41 and the light guide 12 is controlled by, for example, the system control circuit 22 to adjust the light flux supplied to the light guide 12. In the field sequential type electronic endoscope, a rotary color filter such as RGB is provided on the optical path together with the diaphragm device.
[0017]
The system control circuit 22 is connected to a front panel 23 (see FIG. 2) provided with various switches and display devices. The system control circuit 22 is linked to the operation of the switches provided on the front panel 23. Then, the driving of the video signal processing circuit 21, the lamp power supply control circuit 43, the diaphragm device 44, and the like is controlled.
[0018]
FIG. 2 is an example of a front view of the processor 20. A front panel 23 is provided from the front right of the processor 20, and the front panel 23 includes, for example, a lamp power switch 23a, brightness adjustment switches 23b and 23c, an air / water pump driving switch 23d, and a lamp life expectancy. An indicator 23e is provided. Further, a switch 24 for turning on the main power is provided at the lower right of the front panel 23, and an electrical connector portion 25 and a light guide connector portion 26 are provided from the front left. The electrical connector portion 25 is for connecting to the signal line of the electronic scope 10, and the light guide connector portion 26 inserts the incident end of the light guide 12 disposed in the electronic scope 10 into the processor 20, This is for optically connecting to the light source unit 40.
[0019]
Next, the relationship between the life of the lamp 41 used in the present embodiment and the applied voltage will be described with reference to FIG.
[0020]
In FIG. 3, the horizontal axis represents the lamp voltage applied to the lamp 41, and the vertical axis represents the lamp life. The lamp voltage on the horizontal axis is expressed as a percentage (%) based on the rated voltage of the lamp (100), and the lamp life on the vertical axis is based on the lamp life (rated life) when driven at the rated voltage constantly (100). ) As a percentage (%). The relationship between the lamp voltage and the lamp life is indicated by a life curve CL. As shown, the lamp life decreases monotonically and rapidly with increasing lamp voltage. That is, as the lamp voltage increases, the total luminous flux emitted from the lamp increases (becomes brighter) and its color temperature also increases. However, the filament temperature rises, so that the filament evaporates and the life is shortened. On the other hand, when the lamp voltage is lowered, the total luminous flux emitted from the lamp is reduced (darkened) and the color temperature thereof is lowered. However, the filament temperature is also lowered, so that evaporation is slowed and the life is extended. For example, assuming that the rated voltage is V ₀ and the rated life is T ₀ (hours), when the lamp 41 is driven at a voltage 1.1V ₀ which is 110% of the rated voltage V ₀ , the lamp life is 30% of the rated life T ₀ , that is, 0.3T ₀ (time). On the other hand, when the lamp 41 is driven at a voltage 0.95V ₀ which is 95% of the rated voltage V ₀ , the lamp life becomes 180% of the rated life T ₀ , that is, 1.8T0 (hours).
[0021]
Next, the operation of the lamp life display process according to this embodiment will be described with reference to FIGS. FIG. 4 is a flowchart of the lamp life expectancy display process, which is repeatedly executed while the electronic endoscope apparatus is being driven.
[0022]
In step S <b> 100, the output level of the video signal output from the image sensor (CCD) 11 (for example, the output level of the luminance signal) is detected by the system control circuit 22 via the video signal 21. That is, information regarding the brightness of the image to be captured is detected by the system control circuit 22. In step S110, the output level (L) of the video signal detected in step S100 is compared with a preset reference level (L ₀ ). This reference level corresponds to a predetermined brightness of the captured image, and can be set / changed by operating the brightness adjustment switches 23b and 23c of the front panel 23 in this embodiment.
[0023]
For example, when the output level (L) of the detected video signal and the reference level (L ₀ ) in step S110 have a relationship of (L−L ₀ )> ΔL with respect to the predetermined amount (ΔL), the brightness of the captured image is increased. Is determined to be brighter than the set brightness, and the process proceeds to step S120. In step S120, the setting of the lamp voltage applied to the lamp 14 is reduced by a predetermined amount (ΔV), and then the process proceeds to step S140.
[0024]
On the other hand, when the output level (L) of the detected video signal and the reference level (L ₀ ) are in a relationship of (L ₀ −L)> ΔL with respect to the predetermined amount (ΔL) in step S110, for example, The brightness is determined to be darker than the set brightness, and the process proceeds to step S130. In step S130, it is first determined whether or not the lamp voltage (V) currently applied to the lamp 14 is, for example, V ≦ V ₀ −ΔV (V ₀ : rated voltage), and if V ≦ V ₀ −ΔV. If so, the setting of the lamp voltage is increased by a predetermined amount (ΔV), and the process proceeds to step S140. If it is determined that the current applied voltage is V> V ₀ −ΔV, the process proceeds to step S140 while the current lamp voltage is maintained. That is, the lamp voltage (V) is always maintained at the rated voltage V ₀ or less. The initial setting of the lamp voltage (V) is, for example, 90% of the rated voltage V ₀ (0.9 V ₀ ), and the lamp is normally driven with this voltage. Note that when V> V ₀ −ΔV, for example, the brightness of the image is adjusted by adjusting the electronic shutter operation of the aperture device 44 and the image sensor (CCD) 11.
[0025]
In step S110, when the output level (L) of the detected video signal satisfies, for example, | L−L ₀ | ≦ ΔL, it is determined that the brightness of the captured image is appropriate, and the process directly proceeds to step S140. . The predetermined amount (ΔV) when changing the lamp voltage may be a constant value, but may be a value correlated with the difference between the output level (L) and the reference level (L ₀ ), for example.
[0026]
In step S140, as will be described later, the value of the index value N that is an index of the remaining usable period, that is, the lamp remaining life corresponding to the usable period in the future, is updated based on the currently applied lamp voltage (V). . When the updating of the index variable N is completed, in step S150, the lamp life expectancy corresponding to the future usable period is displayed on the lamp life expectancy indicator 23e of the front panel 23 based on the updated index value N. Thus, the lamp life expectancy display process of this embodiment is completed.
[0027]
Next, the index value update process (S140) and the lamp life expectancy display process (S150) of this embodiment will be described with reference to FIGS.
[0028]
The index value N is stored in a memory M (see FIG. 1) made of, for example, an EEPROM provided in the system control circuit 22, and is read from the memory M when the power is turned on, for example. The index value N is set to the initial value N ₀ when the lamp is replaced with a new one. The initial value N ₀ is set, for example, by operating a reset button (not shown) during lamp replacement. In the index value update process in step S140, the predetermined value ΔN is subtracted from the index value N based on the current lamp voltage V every time the predetermined time ΔT elapses (for example, every time the lamp life display process is executed). (N−ΔN) is overwritten and stored in the memory M as a new index value N. The value of the predetermined value ΔN differs depending on the value of the lamp voltage V, and is stored in the memory M as a lookup table, for example.
[0029]
Assuming that the value ΔN ₀ when the rated voltage V ₀ is applied to the lamp 41 is ΔN ₀ and the lamp life when the voltage Va is applied to the lamp 41 is Ta, the predetermined value ΔN at this time is, for example, ΔN = T ₀ / Ta · ΔN ₀ = α · ΔN ₀ Here, T ₀ is the rated life, α = T ₀ / Ta. For example, in FIG. 3, when the lamp voltage is 95%, the lamp life is 180% of the rated life T ₀ , so α = 100/180, and the value of the predetermined value ΔN subtracted from the index value N every predetermined time ΔT is This is about 56% of the predetermined value ΔN ₀ when the rated voltage is applied. That is, the rate at which the index value N decreases per unit time is increased or decreased according to the value of the applied lamp voltage V. Since the life curve CL of FIG. 3 is monotonically decreasing, the value of the predetermined value ΔN is small when the lamp voltage is low, and the value of the predetermined value ΔN is large when the lamp voltage is high.
[0030]
Further, during the predetermined value the value of .DELTA.N ₀ is the nominal life T ₀ of the predetermined value .DELTA.N ₀ from the index value N at every predetermined time ΔT elapses when the initial value N ₀ and the rated voltage V ₀ which index value N is applied When the value is reduced, the index value N is set to 0. That is, N ₀ = ΔN ₀ · n holds for an integer n where T ₀ = ΔT · n.
[0031]
The lamp life expectancy indicator 23e includes, for example, a plurality of segments, and graphically displays the life expectancy of the lamp according to the index value N. The lamp life expectancy indicator 23e of the present embodiment is a bar graph in which five rectangular segments are arranged in a line, and each segment is turned on or off in accordance with the index value N. That is, as shown in FIG. 5A, all the segments are turned on immediately after the lamp replacement, and when the index value N decreases by 40% from the initial value N ₀ (N = 0.6N ₀ ), for example, FIG. As shown in b), the right two segments are turned off and only the left three segments are turned on. When the index value N becomes 0, it means that all segments are extinguished and the lamp life has been exhausted. For example, in the case of a halogen lamp with a rated life of 50 hours, one segment corresponds to 10 hours when driving the lamp at the rated voltage. Accordingly, FIG. 5B shows that if the lamp is driven at the rated voltage, the lamp can be used for 30 hours. When driving at 95% of the rated voltage, it can be used for 54 hours (= 30 hours × 1.8).
[0032]
As described above, according to the present embodiment, since the lamp life expectancy corresponding to the future usable period of the lamp is displayed, it is possible to predict the time when the lamp will be turned off. As a result, when the lamp life approaches, the lamp can be replaced in advance to prevent the lamp from running out during endoscopic observation, and a replacement lamp can be prepared according to the lamp life. Further, since the lamp life expectancy is calculated according to the applied lamp voltage, the lamp life expectancy can be accurately displayed even if the lamp voltage is changed midway. That is, in this embodiment, the lamp voltage is automatically controlled in order to keep the brightness of the captured image at the set reference level, but the lamp life expectancy is accurately calculated even in such a case. Further, in this embodiment, the lamp voltage is suppressed to the rated voltage or lower, and normally, the lamp is controlled to be driven around 90% of the rated voltage, so that the lamp life can be extended.
[0033]
In this embodiment, the lamp life expectancy indicator is provided on the front panel. However, for example, a bar graph as shown in FIG. 5 may be superimposed and displayed on the screen of the TV monitor by a predetermined operation. In the present embodiment, only the lamp life expectancy is displayed. However, for example, when the index value is equal to or less than a predetermined value, display means for displaying a warning for prompting lamp replacement may be provided.
[0034]
In the present embodiment, the lamp life expectancy is graphically displayed, but may be expressed using a numerical value or the like (for example, the index value itself is displayed with the index value N being a number from 0 to 100). Further, for example, the lamp voltage may be specified, and the usable time (ΔT · N / ΔN) when the lamp is used at that voltage may be calculated from the index value and displayed.
[0035]
Further, since the color temperature of the lamp slightly changes when the lamp voltage is changed, the white balance may be adjusted according to the applied lamp voltage. In the present embodiment, the lamp voltage is automatically controlled so as to achieve the brightness of the set reference level, but the lamp voltage may be manually controlled.
[0036]
Although the present embodiment relates to an electronic endoscope apparatus, the present invention may be applied to a fiberscope light source apparatus.
[0037]
【The invention's effect】
As described above, according to the present invention, the remaining usable period of the light source used for the illumination of the endoscope can be accurately predicted.
[Brief description of the drawings]
FIG. 1 is a block diagram schematically showing a circuit configuration of an electronic endoscope apparatus according to an embodiment of the present invention.
FIG. 2 is a front view of a processor according to the present embodiment.
FIG. 3 is a graph showing the relationship between lamp voltage and lamp life.
FIG. 4 is a flowchart of lamp life expectancy display processing.
FIG. 5 is a diagram showing a display state of a lamp life expectancy indicator.
[Explanation of symbols]
10 Electronic scope 11 Image sensor (CCD)
20 Video signal processor (processor)
21 Video signal processing circuit 22 System control circuit 23e Lamp life expectancy indicator 40 Light source 41 Lamp (halogen lamp)
43 Lamp power control circuit M Memory

Claims (9)

A lamp used as an illumination light source during endoscopic observation;
A lamp power supply for supplying power to the lamp;
Lamp life expectancy calculating means for calculating a lamp life expectancy corresponding to a remaining usable period of the lamp based on a lamp voltage applied to the lamp ,
The lamp life expectancy calculation means calculates the lamp life expectancy by subtracting a predetermined value corresponding to a lamp voltage every predetermined time from an index value set as an initial value at the time of lamp replacement while power is supplied to the lamp. And
The ratio between the first predetermined value corresponding to the first lamp voltage and the second predetermined value corresponding to the second lamp voltage at the predetermined value corresponding to the lamp voltage is the second lamp voltage. A lamp life calculation apparatus for an endoscope apparatus, characterized in that the lamp life is equal to a ratio between a lamp life when driven and a lamp life when driven with the first lamp voltage . The lamp life expectancy calculation apparatus for an endoscope apparatus according to claim 1 , further comprising a memory in which a correspondence between the lamp voltage and the predetermined value is stored as a lookup table.   The lamp life expectancy calculation apparatus for an endoscope apparatus according to claim 1, further comprising lamp life expectancy notifying means for notifying information related to lamp life expectancy based on the lamp life expectancy calculated by the lamp life expectancy calculating means. The lamp life expectancy calculation device for an endoscope apparatus according to claim 3 , wherein the lamp life expectancy notifying means includes lamp life expectancy display means for displaying the lamp life expectancy. The lamp life expectancy calculation device for an endoscope apparatus according to claim 4 , wherein the lamp life expectancy display means graphically displays the lamp life expectancy.   Means for detecting the brightness of the image, level setting means for setting a reference level of the brightness of the image, and lamp voltage control means for controlling the lamp voltage in the lamp power supply unit, wherein the lamp voltage control means The lamp voltage is controlled so as to maintain the brightness of the image at the reference level based on information on the brightness of the image obtained by the means for detecting the brightness of the image. The lamp life expectancy calculation device of the endoscope apparatus described. The endoscope is an electronic endoscope provided with an image sensor, and the means for detecting the brightness of the image detects the brightness of the image based on a video signal of an image captured by the image sensor. The lamp life expectancy calculating apparatus for an endoscope apparatus according to claim 6 . 8. The lamp life calculation apparatus for an endoscope apparatus according to claim 7 , wherein the lamp voltage control means controls the lamp voltage to be equal to or lower than a rated voltage. An electronic endoscope apparatus comprising: a video signal processing device provided with the lamp life expectancy calculating device according to any one of claims 1 to 8 .

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