CN104799811B - A kind of illumination light control circuit for fundus photography - Google Patents

Abstract

The invention discloses a kind of illumination light control circuit for fundus photography, relate to fundus photography field, including: LED illumination lamp is driven by triangular wave or the sawtooth waveforms signal of telecommunication, produce that a branch of triangular wave or zig-zag illumination light, triangular wave or zig-zag illumination light pass sequentially through illumination lens set, semi-transparent semi-reflecting prism, eyeglass and object lens are irradiated to the optical fundus of tested human eye；The reflection light returned from the fundus reflex of tested human eye passes sequentially through again eyeglass and is imaged on imageing sensor with object lens, semi-transparent semi-reflecting prism, image-forming objective lens；Imageing sensor obtains each frame video image of one or several triangular waves or sawtooth waveforms or sawtooth period, and transmits to computer, and it carries out slip frame cumulative mean to frame video image each in time span, obtains definition higher eye fundus image signal.By such scheme can reduce illumination intensity more than half, considerably reduce the stimulation degree to subjects；And improve the definition of eye fundus image, reduce production cost.

Description

A kind of illumination light control circuit for fundus photography

Technical field

The present invention relates to fundus photography field, particularly relate to a kind of illumination light control circuit for fundus photography.

Background technology

During examination of ocular fundus, need to be observed retina optic nerve and the macula lutea of inside ofeye by pupil.When light is pointed into eyes, Pupil can reduce to adapt to light by nature, and this can hinder the inspection to optical fundus.In order to solve this problem, it is the most right to be usually Eyes are anaesthetized, and make pupil be unlikely to change with the change of light.

Finding during actual application, after subjects's mydriasis, the time of recovery is long, if now meeting high light, human eye can be very Uncomfortable, even damage retina, therefore, development in recent years exempts from the fundus photography technology of mydriasis, and this technology utilizes Gao Ling Sensitivity photoelectric device under poor light condition to fundus imaging, but relatively costly, it is impossible to expand range of application.

Summary of the invention

The invention provides a kind of illumination light control circuit for fundus photography, present invention achieves in the case of not mydriasis Shooting high-quality fundus photograph, and save cost of manufacture, described below:

A kind of illumination light control circuit for fundus photography, including: eyeglass and object lens, semi-transparent semi-reflecting prism, illuminating mirror Sheet group, image-forming objective lens, imageing sensor, LED illumination lamp and computer, wherein, described eyeglass and object lens, described half Saturating half anti-prism, described image-forming objective lens and described imageing sensor are arranged in order, at described semi-transparent semi-reflecting prism and described LED Described illumination lens set it is provided with between illuminating lamp,

Described LED illumination lamp is driven by triangular wave or the sawtooth waveforms signal of telecommunication, produces a branch of triangular wave or zig-zag illumination Light, triangular wave or zig-zag illumination light pass sequentially through described illumination lens set, described semi-transparent semi-reflecting prism, described eyeglass With the optical fundus that object lens are irradiated to tested human eye；

The reflection light returned from the fundus reflex of tested human eye passes sequentially through again described eyeglass and object lens, described semi-transparent semi-reflecting rib Mirror, described image-forming objective lens are imaged on described imageing sensor；

Described imageing sensor obtains each frame video image of one or several triangular waves or sawtooth waveforms or sawtooth period, and Transmission is to computer, and computer carries out slip frame cumulative mean to frame video image each in time span, obtains definition higher Eye fundus image signal.

Further, described frame video image each in time span is carried out slip frame cumulative mean, obtain definition higher The step of eye fundus image signal particularly as follows:

$Y_i=\frac{1}{N}\underset{j=0}{\overset{j=n-1}{\Σ}}{X}_{i-j}$

In formula: Y_iOutput picture frame for the i moment；X_I-jOutput picture frame for the i-j moment；N be one or several three The frame number of the video image that described imageing sensor obtains in angle ripple or sawtooth period.

Further, described imageing sensor is particularly as follows: ccd image sensor.

Further, described imageing sensor is particularly as follows: cmos image sensor.

The technical scheme that the present invention provides provides the benefit that: the present invention by being defined to triangular wave or zig-zag by illumination light Illumination light, and the video image obtained photographic head for time span with one or several triangular waves or sawtooth period carries out Moving average, obtains eye fundus image signal.By such scheme can reduce illumination intensity more than half, considerably reduce Stimulation degree to subjects；And improve the definition of eye fundus image, reduce production cost, expand actual application In scope.

Accompanying drawing explanation

Fig. 1 is the structural representation of a kind of illumination light control circuit for fundus photography of embodiment 1；

Fig. 2 is the structural representation of a kind of illumination light control circuit for fundus photography of embodiment 2；

Fig. 3 is the structural representation of a kind of illumination light control circuit for fundus photography of embodiment 3.

In accompanying drawing, the list of parts representated by each label is as follows:

1: tested human eye；2: eyeglass and object lens；

3: semi-transparent semi-reflecting prism；4: illumination lens set；

5: image-forming objective lens；6: imageing sensor；

7:LED illuminating lamp；8: computer；

61:CCD imageing sensor；62:CMOS imageing sensor.

Detailed description of the invention

For making the object, technical solutions and advantages of the present invention clearer, below embodiment of the present invention is made the most detailed Thin description.

Embodiment 1

Seeing Fig. 1, a kind of illumination light control circuit for fundus photography, including: eyeglass and object lens 2, semi-transparent semi-reflecting Prism 3, illumination lens set 4, image-forming objective lens 5, imageing sensor 6, LED illumination lamp 7 and computer 8, wherein, connect Eyepiece is arranged in order with object lens 2, semi-transparent semi-reflecting prism 3, image-forming objective lens 5 and imageing sensor 6, at semi-transparent semi-reflecting prism 3 And between LED illumination lamp 7, it is provided with illumination lens set 4；

Wherein, LED illumination lamp 7 is driven by triangular wave or the sawtooth waveforms signal of telecommunication, produces a branch of triangular wave or zig-zag is shone Mingguang City, this triangular wave or zig-zag illumination light pass sequentially through illumination lens set 4, semi-transparent semi-reflecting prism 3, eyeglass and thing Mirror 2 is irradiated to the optical fundus of tested human eye 1；The reflection light returned from the fundus reflex of tested human eye 1 passes sequentially through again eyeglass Be imaged on imageing sensor 6 with object lens 2, semi-transparent semi-reflecting prism 3, image-forming objective lens 5, if imageing sensor 6 obtain one or Doing a triangular wave or sawtooth waveforms or each frame video image of sawtooth period, and transmit to computer 8, computer 8 is to the time In length (the most several frames to the time of tens frames, the needs in applying according to reality are set), each frame video image enters Line slip frame cumulative mean, obtains definition higher eye fundus image signal.

$Y_i=\frac{1}{N}\underset{j=0}{\overset{j=n-1}{\Σ}}{X}_{i-j}$

In formula: Y_iOutput picture frame for the i moment；X_I-jOutput picture frame for the i-j moment；N be one or several three The frame number of the video image that imageing sensor 2 obtains in angle ripple or sawtooth period.

It is that x is sampled value to amplitude, if uniform sampling N (> > 1 within the regular hour) put and be averaged, To meansigma methods be

$\stackrel{\‾}{x}=\frac{1}{N}\underset{i=1}{\overset{N}{\Σ}}\[x_i\]=\frac{1}{N}N(\[x\]+{\mathrm{\Δx}}_i)=\[x\]+{\mathrm{\Δx}}_i---\left(1\right)$

Wherein, [x] is that x is quantified by analog-digital converter, namely the positive integer that round off rounding obtains.x_iIt is i-th The amplitude of point, [x_i] it is that analog-digital converter is to x_iQuantify, namely the positive integer that round off rounding obtains.

(1) formula shows, is repeatedly averaged a signal sampling comparing " totally ", can not improve its precision, The error of obtained meansigma methods is identical with the error of unitary sampling, for Δ x_i。

If being that x is sampled sawtooth waveforms to amplitude, uniform sampling N (> > 1 within the regular hour equally) put and carry out Averagely, the meansigma methods obtained is

$\stackrel{\‾}{x}=\frac{1}{N}\underset{i=1}{\overset{N}{\Σ}}\[x_i\]=\frac{1}{N}\underset{i=1}{\overset{N}{\Σ}}\[m_i+{\mathrm{\Δx}}_i\]---\left(2\right)$

Wherein, x_i=m_i+Δx_i, m_i=[x_i].Namely m_iIt is that rounding obtains positive integer, and Δ x_iBe be rounded after lose " at random " error.

(2) formula can obtain further with arithmetic series sum formula:

$\begin{array}{c}\stackrel{\‾}{x}=\frac{1}{N}\underset{i=1}{\overset{N}{\Σ}}{m}_i+\frac{1}{N}\underset{i=1}{\overset{N}{\Σ}}{\mathrm{\Δx}}_i=\frac{1}{N}\frac{1}{2}(0+\[x\])N+\frac{1}{N}\underset{i=1}{\overset{N}{\Σ}}{\mathrm{\Δx}}_i\\ =\frac{1}{2}\[x\]+\frac{1}{N}\underset{i=1}{\overset{N}{\Σ}}{\mathrm{\Δx}}_i\end{array}---\left(3\right)$

(3) the previous item in formula is the value after quantifying, although less than the result of (1) formula half, but according to error theory, The precision of one data does not change because being multiplied by a fixing non-zero constant.But one next is the random number of zero-mean, Compare to reduce in (1) formulaTimes, therefore, equally may be used after sawtooth waveforms or triangular wave pumping signal are carried out over-sampling To be improved the effect of precision, and need not another external high-frequency disturbing signal.

The embodiment of the present invention is to the model of each device in addition to doing specified otherwise, and the model of other devices does not limits, as long as The device of above-mentioned functions can be completed.

Embodiment 2

See the district of Fig. 2, a kind of illumination light control circuit for fundus photography, this illumination light control circuit and embodiment 1 Not being that imageing sensor 6 is specially ccd image sensor 61, this illumination light control circuit includes: eyeglass and object lens 2, semi-transparent semi-reflecting prism 3, illumination lens set 4, image-forming objective lens 5, ccd image sensor 61, LED illumination lamp 7 and Computer 8, wherein, eyeglass depend on object lens 2, semi-transparent semi-reflecting prism 3, image-forming objective lens 5 and ccd image sensor 61 Secondary arrangement, is provided with illumination lens set 4 between semi-transparent semi-reflecting prism 3 and LED illumination lamp 7；

Wherein, LED illumination lamp 7 is driven by triangular wave or the sawtooth waveforms signal of telecommunication, produces a branch of triangular wave or zig-zag is shone Mingguang City, this triangular wave or zig-zag illumination light pass sequentially through illumination lens set 4, semi-transparent semi-reflecting prism 3, eyeglass and thing Mirror 2 is irradiated to the optical fundus of tested human eye 1；The reflection light returned from the fundus reflex of tested human eye 1 passes sequentially through again eyeglass It is imaged on ccd image sensor 61, ccd image sensor 61 with object lens 2, semi-transparent semi-reflecting prism 3, image-forming objective lens 5 Obtain each frame video image of one or several triangular waves or sawtooth waveforms or sawtooth period, and transmit to computer 8, meter Calculation machine 8 is to each in time span (the most several frames to the time of tens frames, the needs in applying according to reality are set) Frame video image carries out slip frame cumulative mean, obtains definition higher eye fundus image signal.

Ccd image sensor 61 in the embodiment of the present invention obtains one or several triangular waves or sawtooth waveforms or sawtooth waveforms week Each frame video image of phase, and frame video image each in time span is carried out slip frame cumulative mean, obtain definition higher The process step of eye fundus image signal same as in Example 1, the embodiment of the present invention does not repeats at this.

The embodiment of the present invention is to the model of each device in addition to doing specified otherwise, and the model of other devices does not limits, as long as The device of above-mentioned functions can be completed.

Embodiment 3

See the district of Fig. 3, a kind of illumination light control circuit for fundus photography, this illumination light control circuit and embodiment 1 Not being that imageing sensor 6 is specially cmos image sensor 62, this illumination light control circuit includes: eyeglass and thing Mirror 2, semi-transparent semi-reflecting prism 3, illumination lens set 4, image-forming objective lens 5, cmos image sensor 62, LED illumination lamp 7 With computer 8, wherein, eyeglass and object lens 2, semi-transparent semi-reflecting prism 3, image-forming objective lens 5 and cmos image sensor 62 are arranged in order, and are provided with illumination lens set 4 between semi-transparent semi-reflecting prism 3 and LED illumination lamp 7；

Wherein, LED illumination lamp 7 is driven by triangular wave or the sawtooth waveforms signal of telecommunication, produces a branch of triangular wave or zig-zag is shone Mingguang City, this triangular wave or zig-zag illumination light pass sequentially through illumination lens set 4, semi-transparent semi-reflecting prism 3, eyeglass and thing Mirror 2 is irradiated to the optical fundus of tested human eye 1；The reflection light returned from the fundus reflex of tested human eye 1 passes sequentially through again eyeglass It is imaged on cmos image sensor 62, cmos image sensor with object lens 2, semi-transparent semi-reflecting prism 3, image-forming objective lens 5 62 obtain one or several triangular waves or sawtooth waveforms or each frame video image of sawtooth period, and transmit to computer 8, Computer 8 is in time span (the most several frames to the time of tens frames, the needs in applying according to reality are set) Each frame video image carries out slip frame cumulative mean, obtains definition higher eye fundus image signal.

Cmos image sensor 62 in the embodiment of the present invention obtains one or several triangular waves or sawtooth waveforms or sawtooth waveforms Each frame video image in cycle, and frame video image each in time span is carried out slip frame cumulative mean, obtain definition more The process step of high eye fundus image signal is same as in Example 1, and the embodiment of the present invention does not repeats at this.

The embodiment of the present invention is to the model of each device in addition to doing specified otherwise, and the model of other devices does not limits, as long as The device of above-mentioned functions can be completed.

It will be appreciated by those skilled in the art that accompanying drawing is the schematic diagram of a preferred embodiment, the invention described above embodiment sequence number Just to describing, do not represent the quality of embodiment.

The foregoing is only presently preferred embodiments of the present invention, not in order to limit the present invention, all in the spirit and principles in the present invention Within, any modification, equivalent substitution and improvement etc. made, should be included within the scope of the present invention.

Claims (4)

1. for an illumination light control circuit for fundus photography, including: eyeglass and object lens, semi-transparent semi-reflecting prism, photograph Bright lens set, image-forming objective lens, imageing sensor, LED illumination lamp and computer, wherein, described eyeglass and object lens, institute State semi-transparent semi-reflecting prism, described image-forming objective lens and described imageing sensor to be arranged in order, at described semi-transparent semi-reflecting prism and described Described illumination lens set it is provided with between LED illumination lamp, it is characterised in that

Described LED illumination lamp is driven by triangular wave or the sawtooth waveforms signal of telecommunication, produces a branch of triangular wave or zig-zag illumination Light, triangular wave or zig-zag illumination light pass sequentially through described illumination lens set, described semi-transparent semi-reflecting prism, described eyeglass With the optical fundus that object lens are irradiated to tested human eye；

The reflection light returned from the fundus reflex of tested human eye passes sequentially through again described eyeglass and object lens, described semi-transparent semi-reflecting rib Mirror, described image-forming objective lens are imaged on described imageing sensor；

Described imageing sensor obtains each frame video image of one or several triangular waves or sawtooth period, and transmits to meter Calculation machine, described computer carries out slip frame cumulative mean to frame video image each in time span, obtains the higher eye of definition Base map image signal.

A kind of illumination light control circuit for fundus photography the most according to claim 1, it is characterised in that described Frame video image each in time span is carried out slip frame cumulative mean, obtains the step of definition higher eye fundus image signal Particularly as follows:

$Y_i=\frac{1}{N}\underset{j=0}{\overset{j=n-1}{\Σ}}{X}_{i-j}$

In formula: Y_iOutput picture frame for the i moment；X_I-jOutput picture frame for the i-j moment；N be one or several three The frame number of the video image that described imageing sensor obtains in angle ripple or sawtooth period；N is the number of sampled point.

A kind of illumination light control circuit for fundus photography the most according to claim 1 and 2, it is characterised in that Described imageing sensor is particularly as follows: ccd image sensor.

A kind of illumination light control circuit for fundus photography the most according to claim 1 and 2, it is characterised in that Described imageing sensor is particularly as follows: cmos image sensor.