CN203037448U - Automatic focal length measurement device for thin concave lens - Google Patents

Abstract

The utility model discloses an automatic focal length measurement device for a thin concave lens. The device comprises an LED light source, a light source filter, a black object screen with a hole, a slideable baffle, a convex lens, a concave lens clamping groove, a light intensity sensor, a black image screen, a transmission rod, a motor, a liquid crystal display, a CPU controller, a starting switch, an ultrasonic ranging sensor, an operation base, a support, a device shell, and a status indication lamp. According to the automatic focal length measurement device for the thin concave lens, the definition of the image can be accurately judged by the light intensity detection, and then the focal length measurement precision of the thin concave lens can be effectively improved. The automatic focal length measurement device for the thin concave lens is advanced, reasonable, effective, high in automation degree and quick and accurate in measurement.

Description

Thin Concave Mirrors Focus self-operated measuring unit

Technical field

The utility model belongs to design and the manufacturing technology field of physical experiment apparatus, relates in particular to a kind of thin Concave Mirrors Focus self-operated measuring unit.

Background technology

In Experiment of College Physics, the measurement of focal distance of thin convex lens is the most basic experiment.Measuring method commonly used has: autocollimatic method, object distance-image distance method, Conjugate method and lens combination are legal.The focal length of measuring thin concavees lens mainly adopts lens combination legal.No matter which kind of method all needs human eye to go to judge the readability of imaging, and then determines picture screen position.Because individual's visual custom is different and the restriction of aberration, therefore, be difficult to determine that accurately the precision of measurement result is generally not high as the screen position.What light source, thing screen and picture screen were chosen in addition is different, also can bring certain influence to the judgement of imaging readability.In sum, if these influence factor stacks, measurement result may occur than mistake.

Following optical principle is arranged in the prior art: if not fogging clear, particularly during edge fog, would be because the light that marginal point in kind sends does not converge on the picture screen causes.Therefore when clear picture, illumination intensity was for maximum when namely light converged at as screen upward.Can carry out the measurement of thin Concave Mirrors Focus according to above-mentioned optical principle.

Particularly, when the distance of shielding the concavees lens draw-in groove when thing is definite value a, according to recessed thin lens imaging formula (1):

$f=\frac{\mathrm{uv}}{u+v}---\left(1\right),$

Wherein, u is object distance, and v is image distance, obtains measuring the formula (2) of Concave Mirrors Focus:

$f=\frac{(b-a)(c-a)}{c}---\left(2\right).$

Thing shields first distance b of picture screen and the second distance c that thing shields the picture screen during based on a value, clear picture, utilizes above-mentioned formula (2) can calculate the focal distance f of concavees lens to be measured.But, still do not utilize above-mentioned technology to realize the measurement mechanism of thin Concave Mirrors Focus so far.

The utility model content

In view of this, the purpose of this utility model is to provide a kind of thin Concave Mirrors Focus self-operated measuring unit, the measuring accuracy of utilizing the optical principle introduced in the background technology and relevant art to improve thin Concave Mirrors Focus effectively.

According to an aspect of the present utility model, a kind of thin Concave Mirrors Focus self-operated measuring unit is provided, and described device comprises: led light source, light source filter, black thing screen with holes, slidably baffle plate, convex lens, concavees lens draw-in groove, light intensity sensor, black picture screen, drive link, motor, LCDs, cpu controller, starting switch, ultrasonic ranging sensor, operation base and support, crust of the device and status indicator lamp.

Preferably, described cpu controller is the central controller of described device, is responsible for the processing of all input data and the output of control signal;

Described led light source provides light source for described device;

Described light source filter is convex lens, and described led light source is arranged on the focal plane of described light source filter, to guarantee that the light that is mapped on the described black thing screen with holes is parallel rays;

Described black thing with holes screen is one to have the black panel in 1 font hole;

Described slidably baffle plate is used for making interior each optical device of described device to seal with respect to the external world, thereby makes the Concave Mirrors Focus measuring process can not be subjected to the influence of extraneous light;

Described convex lens are used for forming compound lens with concavees lens to be measured, thereby carry out the measurement of Concave Mirrors Focus;

Described concavees lens draw-in groove is half circular draw-in groove, is used for holding concavees lens to be measured;

Described light intensity sensor is attached on the described black picture screen, carrying out the detection of light intensity, and testing result is delivered to described cpu controller handle;

Described black picture screen is fixed on the described drive link, can move with described drive link;

The movement of the described drive link of described direct motor drive;

Described drive link is threaded, and it is mobile to drive described black picture screen fixed thereon under the driving of described motor;

Described ultrasonic ranging sensor is fixed on the lower end of described black thing with holes screen, measuring the distance between described black thing screen with holes and the described black picture screen, and measurement result is delivered to described cpu controller handle;

Described operation base and support are supported each optical device of described device, and guarantee that the photocentre of each optical device all is in sustained height;

Described LCDs numeral shows the focal length of the concavees lens of surveying;

Described status indicator lamp is indicated the running status of each controllable component in the described device;

Described starting switch is used for connecting the power supply of described device to start described device; And

Described crust of the device provides mechanical protection for the optical device in the described device and miscellaneous part.

Preferably, described cpu controller is embodied as the main control board in the described device.

According to technique scheme, the utility model is accurately judged the readability of imaging by the detection of light intensity, thereby has improved the measuring accuracy of thin Concave Mirrors Focus effectively.Device of the present utility model is rationally advanced, and the automaticity height is measured quick and precisely, is a kind of effective thin Concave Mirrors Focus self-operated measuring unit.

Description of drawings

Fig. 1 is the synoptic diagram in kind of thin Concave Mirrors Focus self-operated measuring unit in the utility model embodiment;

Fig. 2 is the functional structure chart of thin Concave Mirrors Focus self-operated measuring unit in the utility model embodiment.

Embodiment

Fig. 1 is the synoptic diagram in kind of thin Concave Mirrors Focus self-operated measuring unit in the utility model embodiment.As shown in Figure 1, the thin Concave Mirrors Focus self-operated measuring unit in the utility model embodiment comprises: led light source 1, light source filter 2, black thing screen 3 with holes, slidably baffle plate 4, convex lens 5, concavees lens draw-in groove 6, light intensity sensor 7, black picture screen 8, drive link 9, motor 10, LCDs 11, cpu controller 12, starting switch 13, ultrasonic ranging sensor 14, operation base and support 15, crust of the device 16 and status indicator lamp 17 etc.

Fig. 2 is the functional structure chart of thin Concave Mirrors Focus self-operated measuring unit in the utility model embodiment.Band arrow dotted line among the figure between each parts represents that light injects the path, and band arrow solid line is represented the transmission path of control signal or data-signal, does not represent that with the solid line of arrow certain annexation is arranged between parts physically.

Below just do further introduction in conjunction with the vitals of thin Concave Mirrors Focus self-operated measuring unit in Fig. 1, the 2 pairs of embodiments.

Cpu controller 12 is central controllers of this thin Concave Mirrors Focus self-operated measuring unit, is responsible for the processing of all input data and the output of control signal, and it specifically can be embodied as the main control board in the device.Led light source 1 is for device provides light source, and its heat radiation of having avoided adopting tungsten lamp to bring waits some problems.Light source filter 2 is convex lens, and led light source 1 is arranged on the focal plane of these convex lens, to guarantee that the light that is mapped on the black thing screen 3 with holes is parallel rays.Black thing with holes screen 3 is one to have the black panel in 1 font hole.Slidably baffle plate 4 is used for making interior each optical device of device to seal with respect to the external world, thereby makes the Concave Mirrors Focus measuring process can not be subjected to the influence of extraneous light.Convex lens 5 are used for forming compound lens with concavees lens to be measured, thereby carry out the measurement of Concave Mirrors Focus.Concavees lens draw-in groove 6 is half circular draw-in groove, is used for holding concavees lens to be measured.Light intensity sensor 7 is attached on the black picture screen 8, carrying out the detection of light intensity, and testing result is delivered to cpu controller 12 handle.Black picture screen 8 is fixed on the drive link 9, can move with drive link 9.Motor 10 drives the movement of drive link.This drive link 9 is threaded, and drives black picture screen 8 fixed thereon and move under the driving of motor 10.Ultrasonic ranging sensor 14 is fixed on the lower end of black thing screen 3 with holes, with the distance between measurement black thing screen 3 with holes and the black picture screen 8, and measurement result is delivered to cpu controller 12 handle.Each optical device of operation base and support 15 supportive devices (comprising led light source 1, light source filter 2, black thing screen 3 with holes, convex lens 5, black picture screen 8 etc.), and guarantee that the photocentre of each optical device all is in sustained height.LCDs 11 numerals show the focal length of institute's survey lens.The running status of each controllable component in status indicator lamp 17 indicating devices.Starting switch 13 is used for the engaging means power supply with starter gear.Crust of the device 16 provides mechanical protection for optical device and the miscellaneous part in installing.

What deserves to be explained is that cpu controller 12 is to be used for carrying out the parts that thin Concave Mirrors Focus is calculated in the utility model.Be the prior art that background technology is introduced owing to be used for optical principle and the computing formula of the thin Concave Mirrors Focus of calculating in the utility model, this cpu controller only is to utilize known hardware device to realize this known computing formula, these computing method itself are not inventive point of the present utility model, and inventive point of the present utility model is structure and the hardware annexation of measurement mechanism.

Thin Concave Mirrors Focus method for automatic measurement in the embodiment comprises the steps:

Step 1: concavees lens to be measured are clipped on the concavees lens draw-in groove.

Step 2: after concavees lens to be measured folder is steady, slide slidably that baffle plate makes each optical device seal with respect to the external world, thereby make measuring process not influenced by extraneous light.

Step 3:CPU controller triggers led light source work, and the led light source emitted light becomes parallel rays behind the light source filter, and 1 font hole on black thing screen with holes evenly is mapped on the convex lens to be measured again, and imaging on black picture screen.

Step 4: light intensity sensor detects the intensity of illumination that black picture screen receives, black picture screen on the motor drives drive link is mobile simultaneously, when light intensity sensor detects the light intensity maximum for the first time, the real image (being equivalent to a virtual object for concavees lens to be measured) that to be light form through convex lens black look like to shield into clearly as the time, brake motor is mobile to stop black picture screen, and start the ultrasonic ranging sensor instrument distance, thereby obtain first distance b that black thing with holes shields black picture screen.

Step 5: the black picture screen on the motor drives drive link continues to move right, when light intensity sensor detects the light intensity maximum for the second time, it is mobile that brake motor stops black picture screen again, and start the sound ranging sensor instrument distance again, thereby obtain black thing with holes shield black picture screen second distance c.

Step 6:CPU controller calculates the focal length of concavees lens to be measured.

Particularly, because operation base and the support of the utility model device guarantee that each optical device photocentre is in sustained height, and led light source, light source filter, black thing screen with holes, convex lens and concavees lens draw-in groove all be in a fixed position, so the distance that black thing with holes shields the concavees lens draw-in groove is certain value a.According to recessed thin lens imaging formula (1):

$f=\frac{\mathrm{uv}}{u+v}---\left(1\right),$

Wherein, u is object distance, and v is image distance, obtains the formula (2) of the employed measurement Concave Mirrors Focus of the utility model device:

$f=\frac{(b-a)(c-a)}{c}---\left(2\right).$

Based on a value, in step 4 resulting first distance b and in step 5 resulting second distance c, utilize above-mentioned formula (2) can calculate the focal distance f of concavees lens to be measured.

What deserves to be explained is, because this optical principle and computing formula are prior art, this cpu controller only is to utilize known hardware device to realize having computing formula now, these computing method itself are not inventive point of the present utility model, and inventive point of the present utility model is structure and the hardware annexation of measurement mechanism.

Preferably, this method can also comprise step 7, and cpu controller shows the Concave Mirrors Focus that calculates in LCDs.

According to technique scheme, the utility model is accurately judged the readability of imaging by the detection of light intensity, thereby has improved the measuring accuracy of thin Concave Mirrors Focus effectively.Device of the present utility model is rationally advanced, and the automaticity height is measured quick and precisely, is a kind of effective thin Concave Mirrors Focus self-operated measuring unit.

Claims (2)

1. A thin concave lens focal length automatic measuring device is characterized in that the device comprises: LED light source, light source filter, black object screen with holes, slidable baffle plate, convex lens, concave lens slot, light intensity sensor, black image screen, Transmission rod, motor, LCD screen, CPU controller, start switch, ultrasonic distance measuring sensor, running base and bracket, device shell and status indicator light, among which, The CPU controller is the central controller of the device, responsible for the processing of all input data and the output of control signals; The LED light source provides a light source for the device; The light source filter is a convex lens, and the LED light source is arranged on the focal plane of the light source filter to ensure that the light incident on the black object screen with holes is a parallel light; The black object screen with holes is a black panel with a 1-shaped hole; The slidable baffle is used to seal each optical device in the device relative to the outside world, so that the process of measuring the focal length of the concave lens will not be affected by external light; The convex lens is used to form a combined lens with the concave lens to be measured, so as to measure the focal length of the concave lens; The concave lens slot is a semicircular slot for accommodating the concave lens to be measured; The light intensity sensor is attached to the black image screen to detect the light intensity, and the detection result is sent to the CPU controller for processing; The black image screen is fixed on the transmission rod and can move with the transmission rod; The motor drives the movement of the transmission rod; The transmission rod is threaded, and driven by the motor, the black image screen fixed on it is driven to move; The ultrasonic ranging sensor is fixed on the lower end of the black object screen with holes to measure the distance between the black object screen with holes and the black image screen, and the measurement results are sent to the CPU controller for processing; The running base and bracket support each optical device of the device, and ensure that the optical centers of each optical device are at the same height; The digital display of the liquid crystal display shows the focal length of the measured concave lens; The status indicator light indicates the operating status of each controllable component in the device; The start switch is used to turn on the power of the device to start the device; and The device housing provides mechanical protection for optics and other components within the device. the 2. The device according to claim 1, wherein the CPU controller is implemented as a main control circuit board in the device. the

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