CN112914495B - Portable handheld vision detector - Google Patents

Abstract

The invention belongs to the technical field of vision testing tools, and particularly relates to a portable handheld vision tester. According to the invention, the vision detection function is realized through the machine body unit, the adjusting column unit and the lighting unit, when in use, the eye socket is abutted against the eye lens barrel of the machine body unit to judge the direction of the E symbol, the direction judged by the eye socket is compared with the direction indicator at the tail part of the machine body sleeve to judge whether the direction is correct or not, and finally, the magnitude of the vision score is obtained through the score displayed by the scale column. The visual testing device has the advantages of light weight and portability, a person to be tested can use the visual testing device through holding the visual testing device by one hand, the visual testing device is internally provided with the visual testing device which is reduced in proportion, the visual testing device is provided with the high-brightness illuminating lamp, the visual testing device can achieve the same function as a common visual testing device with a lamp box, the direction of the visual testing device and the distance between all optical devices in the visual testing device can be adjusted by rotating the visual testing device and the scale column, and meanwhile, the clamping structure is arranged, so that the visual testing device and the illuminating lamp are relatively fixed and are not easy to shake.

Description

Portable handheld vision detector

Technical Field

The invention belongs to the technical field of vision testing tools, and particularly relates to a portable handheld vision tester.

Background

The vision testing tool is used for measuring the vision device or the general name of a chart, the measuring mode is generally that a person to be tested judges the direction of a symbol used for testing, the vision condition of the person to be tested is evaluated through corresponding scores, the vision standard disk is mainly composed of E-shaped words with different opening directions and different sizes, however, the normal vision standard disk requires the person to be tested to stand at a distance of 3-5 meters from the vision standard disk, a high-brightness lamp box is generally needed, the requirement on a testing field is high, and qualified vision testing is difficult to be carried out on places (such as spectacle stores) with vision testing requirements but without large business places, so that an instrument which is not limited by the field and is convenient for the person to be tested to carry out vision testing at any time is urgently needed on the market.

The Chinese patent publication No. CN111657848A, publication No. 2020.09.15 discloses a portable optotype disk lamp box, which comprises a lamp box body, a base and a rearview mirror; the base comprises a base body, two wheels and two supporting feet; the seat body is provided with a storage cavity, the top surface of the seat body is provided with a cover plate for opening and closing the storage cavity, and one side of the seat body, which is arranged on the cover plate, is provided with a support rod; the lamp box body is sleeved on the supporting rod in a sliding manner and is provided with a hand-screwed locking screw; the left side and the right side of the lamp box body are both provided with connecting seats, the connecting seats are made of iron, and one side of each connecting seat far away from the lamp box body is provided with a hemispherical groove; the rearview mirror is movably arranged in the accommodating cavity and comprises a mirror body, a connecting rod and a spherical magnet, wherein the mirror body is fixedly connected with the spherical magnet through the connecting rod; the mirror body can be adsorbed and installed on the connecting seat through the spherical magnet and rotates relative to the connecting seat.

However, the invention has the defects that although the problem that the existing sighting disc lamp box is inconvenient to carry and is not provided with a rearview mirror is solved, a person to be tested still needs to stand at a distance of 5 meters from the lamp box, the using range of the sighting disc is limited, a lamp box with high brightness is needed, the occupied space is large, and meanwhile, the needed electric power is high.

Disclosure of Invention

The invention aims to provide a portable handheld vision detector which has the advantages of light weight and portability, a person to be detected can use the portable handheld vision detector through holding the portable vision detector by one hand, a scale-reduced sighting target disc is arranged in the portable vision detector, standard E-shaped sighting targets in four directions are provided, a high-brightness illuminating lamp is arranged in the portable vision detector, the same function as a common sighting target disc with a lamp box can be realized, the direction of the sighting target disc and the relative position of each optical device in the sighting target disc can be adjusted by rotating the sighting target disc and a scale column, and meanwhile, a clamping structure is arranged to enable the sighting target disc and the illuminating lamp to be relatively fixed and not easy to shake.

The invention adopts the technical proposal that: the portable handheld vision detector comprises a body unit which is used for being held by a user, an adjusting column unit which is arranged in the body unit and used for changing the direction of a visual target and the observation distance, and an illumination unit which is arranged in the body unit and is clamped with the adjusting column unit and used for illuminating an eye chart.

The further preferable technical scheme is as follows: the body unit comprises a body sleeve, a lens barrel arranged on the body sleeve, an eyepiece arranged in the lens barrel, a dust cover connected on the lens barrel, a starting button arranged on the body sleeve and used for opening or closing the lighting unit, a sliding groove arranged in the body sleeve and used for installing the lighting unit, an objective arranged in the body sleeve, an objective adjusting column arranged on the objective, an objective sliding column, an objective sliding opening used for installing the objective adjusting column, and an objective sliding groove used for installing the objective sliding column.

The eye lens barrel is made of sterile flexible materials, such as food grade silica gel, has the advantages of reducing the compression of the machine body to the eyebox of the user, being convenient and practical, enabling the eye lens barrel to be tightly attached to the eyebox of the user, the external light source is prevented from irradiating into the machine body sleeve, the accuracy of measurement is improved, and in addition, preferably, a flat mirror can be arranged in the eye lens barrel and matched with the dust cover, so that external dust is prevented from entering into the machine body sleeve, and the internal environment is polluted to further influence the vision detection result.

In addition, because the distance between the body sleeve and the eye glass is smaller, the lower-vision person cannot see the eye glass clearly by only moving the eye glass, and the eye glass and the object glass are arranged, and the positions of the eye glass and the eye glass relative to the eye glass disk are adjustable, so that the visual angle of the eye glass seen by an observer is the same as that of a standard eye glass by utilizing an optical principle.

In addition, be provided with the battery jar next door of turn-on button, be convenient for the illumination unit provides electric power, because the illumination unit must have certain illumination intensity, but very easily produces irregular light reflection, scattering etc. in the narrow and small space, so fuselage sleeve internal surface is through meticulous special processing, reduces the reflection of internal surface to light to avoid stray light to produce the influence to the person being inspected in the eyesight inspection process.

The further preferable technical scheme is as follows: the adjusting column unit comprises a scale column for adjusting the position of the lighting unit and used for indicating the eye socket distance between the eye mark disk symbol and the eye socket of a user, a rotating ring arranged on the scale column, and an eye mark disk arranged on the scale column and marked with the eye mark disk symbol.

The scale column is marked with the same score as a common sighting mark disk, the position flush with the tail edge of the machine body sleeve is the score size of the current test, and the rotating ring is used for adjusting the direction of an E symbol to be tested on the sighting mark disk, so that the symbol direction is randomized, and the situation that a final detection result is meaningless due to the fact that a detector remembers the direction of the E symbol after multiple vision tests is avoided.

The further preferable technical scheme is as follows: the adjusting column unit further comprises a scale column cavity arranged in the scale column, an end hole arranged at one end of the scale column and communicated with the scale column cavity, a first penetrating hole arranged on the arc-shaped side face of the scale column and communicated with the scale column cavity, a positioning block part arranged in the scale column cavity and used for fixing the rotating visual standard disc in a mode of clamping the lighting unit, and a pushing column part arranged on the scale column and used for keeping the clamping state of the positioning block part.

The purpose of setting up the scale post cavity is convenient the scale post is inside to be placed the block structure, and then fixes look the position of mark dish for "E" sign can be accurate aim at lighting unit, the person of being convenient for sees clearly, wherein is located locating piece portion in the scale post cavity is used for fixing look the position of mark dish, promote the post portion is used for promoting locating piece portion accomplishes the block.

The further preferable technical scheme is as follows: the push column part comprises a push column which is connected with the positioning block part and outwards penetrates out of the end hole, a push column clamping box which is arranged on the scale column and used for installing the push column, two push column second holes which are arranged on the push column clamping box and used for installing the push column, a limit block groove which is arranged in the push column clamping box and is positioned on the push column, a limit block which is arranged in the limit block groove, a limit block baffle which is arranged at one end of the limit block and is positioned in the limit block groove, a limit block baffle ring which is arranged at the opening of the limit block groove and used for blocking the limit block baffle, a limit block tension spring which is arranged on the limit block and sleeved on the limit block, and a limit block hole which is arranged on the push column clamping box and used for clamping the limit block.

The stopper groove is used for installing the stopper, and makes the stopper can reciprocate, the stopper passes through the spacing hole is fixed promote the post, make promote the post and keep in the state of pressing down, and can be through the people press down the stopper makes it resets to promote the post, the effect of stopper baffle ring is on the one hand in preventing the stopper is followed the stopper hole pops out, on the other hand is used for with the stopper baffle cooperation is fixed the stopper extension spring, the stopper extension spring is used for giving the stopper an ascending power makes the stopper can automatic card go into the stopper hole.

The further preferable technical scheme is as follows: the positioning block part comprises a positioning box arranged on the inner side end face of the cavity of the scale column, a pushing column third hole arranged on the positioning box and used for installing the pushing column, a spring installation cylinder arranged on the inner side wall of the positioning box, a pushing column spring arranged in the spring installation cylinder and contacted with the pushing column, a pushing column plate arranged on the pushing column and positioned in the positioning box, a sliding column arranged on the pushing column plate, a rotating ring arranged in the positioning box, a rotating ring column arranged on the inner side face of the positioning box and used for installing the rotating ring, a rotating block with grooves and used for clamping the sliding column, a rotating trapezoid block arranged on the rotating ring, a positioning block second hole arranged on the positioning box, a positioning block arranged on the positioning block second hole, a spring baffle arranged on the positioning block and a positioning block spring sleeved on the positioning block.

The positioning box is used for accommodating parts for completing a positioning task of the optotype disc, the third hole of the pushing column is used for installing the pushing column and can move left and right freely, the spring installation cylinder is provided with a pushing column spring, the purpose is to give an outward force when the pushing column is reset, the pushing column plate is used for driving the grooved rotating block to rotate and then drive the rotating ring to rotate through the sliding column, finally the rotating trapezoid block is driven to rotate, the rotating ring column is used for fixing the rotating center position of the rotating ring, the rotating trapezoid block drives the positioning block to move forward when rotating, the spring baffle is used for fixing the positioning block spring in a matching manner with the edge plane of the second hole of the positioning block, and the positioning block spring pushes the positioning block to be separated from the clamping state of the lighting unit through an inward pushing force.

The further preferable technical scheme is as follows: the positioning block part also comprises a roller column arranged on the positioning block and a roller arranged on the roller column.

The roller column is fixed on the positioning block, the roller is sleeved on the roller column, and the purpose of the roller is to prevent the rotating trapezoid block from generating larger friction force with the positioning block, so that the positioning block is blocked on the second hole of the positioning block.

The further preferable technical scheme is as follows: the lighting unit comprises a sliding cylinder for mounting the sighting disc, a mounting ring arranged on the sliding cylinder, an internal thread groove arranged on the sliding cylinder, an internal thread hole arranged on the mounting ring, bolts screwed on the internal thread groove and the internal thread hole, a positioning groove arranged on the mounting ring and used for clamping the positioning block, and a sliding block arranged on the sliding cylinder and mounted on the sliding groove.

The sliding cylinder is clamped on the sliding groove through the sliding block and can horizontally move left and right, the mounting ring is installed on the sliding cylinder through the bolt and used for clamping and fixing the sighting mark disc, and the positioning groove is used for clamping and fixing the positioning block, so that the positions of the scale column and the sliding cylinder are relatively fixed.

The further preferable technical scheme is as follows: the lighting unit further comprises a detection hole arranged on the sliding cylinder and a lighting lamp arranged below the detection hole and connected with the starting button through a wire.

The detection hole is used for penetrating one E symbol on the sighting target disk, so that a person to be detected can clearly see which symbol on the sighting target disk, the illuminating lamp is arranged below the detection hole, the effect of a common sighting target disk lamp box is achieved in the relatively dark environment of the machine body sleeve, and the person to be detected can clearly see the symbol on the sighting target disk.

The further preferable technical scheme is as follows: the fuselage cell also includes a direction indicator disposed on the bottom edge of the fuselage sleeve, and the adjustment column cell also includes an arrow indicating block disposed on the scale column that points to the direction indicator.

Along with the rotation of the scale column, the arrow indication blocks point to direction indicators in different directions to play a role in publishing detection answers, so that a person to be detected clearly knows whether the person to be detected observes an E symbol in the correct direction or not, and the arrow indication blocks and the direction indicators cooperate to play a role in vision detection personnel.

The invention is used for a user to hold the machine body unit, an adjusting column unit which is arranged in the machine body unit and used for changing the direction of the sighting target and the observation distance, and an illumination unit which is arranged in the machine body unit and is clamped with the adjusting column unit and used for illuminating the visual acuity chart. The invention has the advantages of light weight and portability, a person to be tested can use the device by holding the device with one hand, the standard E-shaped sighting target in four directions is provided in the detector, the high-brightness illuminating lamp is arranged, the same function as the common sighting target disk with the lamp box can be realized, the direction of the sighting target disk and the relative position of each optical device in the sighting target disk can be adjusted by rotating the sighting target disk and the scale column, and meanwhile, the clamping structure is arranged, so that the sighting target disk and the illuminating lamp are relatively fixed and are not easy to shake.

Drawings

Fig. 1 is a schematic diagram of the whole structure of the vision detector in the present invention.

Fig. 2 is a schematic structural view of a joint between an adjusting column unit and a lighting unit in the present invention.

Fig. 3 is a schematic structural view showing a state of a dial through a detection hole in the present invention.

Fig. 4 is a schematic diagram of the structure of the pointing direction indicator of the arrow pointing block in the present invention.

Fig. 5 is a schematic cross-sectional view of a graduated cylinder according to the present invention.

Fig. 6 is a schematic structural view of the area a in fig. 5 according to the present invention.

Fig. 7 is a schematic structural view of the area B in fig. 5 according to the present invention.

Detailed Description

The following description is of the preferred embodiments of the invention and is not intended to limit the scope of the invention.

Examples: as shown in fig. 1, 2, 3, 4, 5, 6 and fig. 7, a portable handheld vision tester includes a body unit 1 for a user to hold, an adjusting column unit 2 provided in the body unit 1 for changing a direction of a visual target and an observation distance, and an illumination unit 3 provided in the body unit 1 and engaged with the adjusting column unit 2 for illuminating an eye chart.

The body unit 1 includes a body sleeve 101, an eyepiece tube 102 provided on the body sleeve 101, an eyepiece 106 provided in the eyepiece tube 102, a dust cover 103 connected to the eyepiece tube 102, a power-on button 104 provided on the body sleeve 101 for turning on or off the illumination unit 3, a slide groove 105 provided in the body sleeve 101 for mounting the illumination unit 3, an objective 107 provided in the body sleeve 101, an objective adjusting column 108 provided on the objective 107, an objective slide column 109, an objective slide opening 110 for mounting the objective adjusting column 108, and an objective slide groove 111 for mounting the objective slide column 109.

In this embodiment, when the instrument is used, the dust cover 103 is firstly opened to observe whether the eyepiece 106 on the eyepiece barrel 102 has dust, if dust can be wiped off by using the glasses cloth, the next vision test measurement is convenient, the machine body sleeve 101 is held by one hand or both hands, the start button 104 is pressed by fingers, at this time, the light source of the lighting unit 3 is turned on to start vision test, the edge of the objective sliding port 110 is provided with a scale, firstly, the distance between the objective 107 and the eyepiece 106 is adjusted, so that a testee can clearly observe the optotype, then the adjusting column unit 2 is adjusted, and the value of the size displayed by the optotype corresponding to the standard vision chart of the current observation optotype is calculated through the scale of the objective sliding port 110 and the scale of the adjusting column unit 2, namely the value observed by the testee at present, so as to realize the capability of the testee to observe the different-size E symbols.

The adjusting column unit 2 includes a scale column 201 for adjusting the position of the illumination unit 3 and indicating the eye distance between the eye mark disk symbol and the eye socket of the user, a rotating ring 202 provided on the scale column 201, and an eye mark disk 203 provided on the scale column 201 and marked with the eye mark disk symbol.

In this embodiment, the adjustment of the adjustment column unit 2 is to adjust the relative position of the scale column 201 and the body sleeve 101, so that the random direction is similar to the random mechanism of the lottery turntable, and the testee rotates the rotation ring 202 by unintentional rotation to make the sighting disc 203 rotate to a direction unknown to the testee, and at this time, the direction judged by the eyesight of the testee is reflected instead of the direction judged by the memory by observing the sighting mark.

The adjusting column unit 2 further comprises a scale column cavity 204 arranged in the scale column 201, an end hole 205 arranged at one end of the scale column 201 and communicated with the scale column cavity 204, a positioning block penetrating hole 206 arranged on the arc-shaped side surface of the scale column 201 and communicated with the scale column cavity 204, a positioning block portion 208 arranged in the scale column cavity 204 and used for fixing the rotating visual target disk 203 in a manner of clamping the lighting unit 3, and a pushing column portion 207 arranged on the scale column 201 and used for keeping the clamping state of the positioning block portion 208.

In this embodiment, when the person to be tested holds the body sleeve 101, the pushing post 207 may be pressed by the thumb or index finger, so as to drive the positioning block 208 to engage with the lighting unit 3, thereby fixing the relative position of the optotype disk 203 and the lighting unit 3, and at this time, vision detection may be started.

The pushing post part 207 comprises a pushing post 207a connected with the positioning block part 208 and penetrating outwards in the end hole 205, a pushing post clamping box 207b arranged on the scale post 201 and used for installing the pushing post 207a, two pushing post second holes 207c arranged on the pushing post clamping box 207b and used for installing the pushing post 207a, a limiting block groove 207d arranged in the pushing post clamping box 207b and positioned on the pushing post 207a, a limiting block 207e arranged in the limiting block groove 207d, a limiting block baffle 207f arranged at one end of the limiting block 207e and positioned in the limiting block groove 207d, a limiting block baffle 207g arranged at the opening of the limiting block groove 207d and used for blocking the limiting block baffle 207f, a limiting block tension spring 207h arranged on the limiting block baffle 207f and the limiting block baffle 207g and sleeved on the limiting block 207e, and a hole arranged on the pushing post clamping box 207b and used for clamping the limiting block 207 e.

In this embodiment, after the person to be tested detects that one item is completed, if the direction of the "E" symbol is to be adjusted, the stopper 207E may be pressed to release the engagement from the stopper hole 207j, at this time, the pushing post 207a pops up under the action of the positioning block 208, the optotype disk 203 is in the disengaged state with the illumination unit 3, and the scale post 201 may be rotated again.

The positioning block portion 208 includes a positioning box 208a provided on an inner side end surface of the scale column cavity 204, a pushing column third hole 208b provided on the positioning box 208a for mounting the pushing column 207a, a spring mounting cylinder 208c provided on an inner side wall of the positioning box 208a, a pushing column spring 208d provided in the spring mounting cylinder 208c and in contact with the pushing column 207a, a pushing column plate 208e provided on the pushing column 207a and in the positioning box 208a, a sliding column 208f provided on the pushing column plate 208e, a rotating ring 208g provided in the positioning box 208a, a rotating ring 208h provided on an inner side surface of the positioning box 208a for mounting the rotating ring 208g, a grooved rotating block 208j provided on the rotating ring 208g for engaging the sliding column 208f, a rotating trapezoid block 208k provided on the rotating ring 208g, a positioning block second hole 208m provided on the positioning box 208a, a second positioning block 208m provided on the rotating ring 208g, a second positioning block 208g provided on the rotating ring 208h provided on the rotating ring 208g, and a positioning block 208n provided on the positioning block 208 n.

The positioning block 208 further includes a roller column 208r disposed on the positioning block 208n, and a roller 208s mounted on the roller column 208 r.

The lighting unit 3 includes a slide cylinder 301 for mounting the optotype disk 203, a mount ring 302 provided on the slide cylinder 301, an internal thread groove 303 provided on the slide cylinder 301, an internal thread hole 304 provided on the mount ring 302, a bolt 305 screwed on the internal thread groove 303, the internal thread hole 304, a positioning groove 306 provided on the mount ring 302 for engaging the positioning block 208n, and a slide block 307 provided on the slide cylinder 301 and mounted on the slide groove 105.

The lighting unit 3 further includes a detection hole 308 provided on the slide cylinder 301, and a lighting lamp 309 provided below the detection hole 308 and connected to the turn-on button 104 by a wire.

The fuselage cell 1 further comprises a direction indicator 112 arranged on the bottom edge of the fuselage sleeve 101, and the adjustment column cell 2 further comprises an arrow indication block 209 arranged on the scale column 201 pointing towards the direction indicator 112.

In this embodiment, in order to know whether the person to be tested looks at the direction of the "E" symbol, the person to be tested may determine that the person to be tested is pointed by the direction indicator 112 pointed by the arrow indication block 209, if the direction determined by the person to be tested is consistent with the direction indicator 112, the result is correct, otherwise, the result is incorrect, and if the result is correct, the current vision value may be obtained through the scale column 201.

The embodiments of the present invention have been described in detail, but the present invention is not limited to the above embodiments, and various modifications may be made without departing from the spirit of the present invention within the knowledge of one of ordinary skill in the art. These are all non-inventive modifications provided that they fall within the scope of the claims of the present invention as defined by the patent statutes.

Claims (7)

1. The portable handheld vision tester is characterized by comprising a machine body unit (1) used for being held by a user, an adjusting column unit (2) arranged in the machine body unit (1) and used for changing the direction and the observation distance of a sighting target, and a lighting unit (3) arranged in the machine body unit (1) and engaged with the adjusting column unit (2) and used for lighting an eye chart; the body unit (1) comprises a body sleeve (101), a lens barrel (102) arranged on the body sleeve (101), an eyepiece (106) arranged in the lens barrel (102), a dust cover (103) connected on the lens barrel (102), a starting button (104) arranged on the body sleeve (101) and used for starting or closing an illumination unit (3), a sliding groove (105) arranged in the body sleeve (101) and used for installing the illumination unit (3), an objective lens (107) arranged in the body sleeve (101), an objective lens adjusting column (108) arranged on the objective lens (107), an objective lens sliding column (109), an objective lens sliding opening (110) used for installing the objective lens adjusting column (108) and an objective lens sliding groove (111) used for installing the objective lens sliding column (109); the adjusting column unit (2) comprises a scale column (201) for adjusting the position of the lighting unit (3) and indicating the distance between the eye chart symbol and the eyeball of the user, a rotating ring (202) arranged on the scale column (201), and an eye chart disc (203) arranged on the scale column (201) and marked with the eye chart symbol; the adjusting column unit (2) further comprises a scale column cavity (204) arranged in the scale column (201), a head hole (205) arranged at one end of the scale column (201) and communicated with the scale column cavity (204), a positioning block penetrating hole (206) arranged on the arc-shaped side face of the scale column (201) and communicated with the scale column cavity (204), a positioning block portion (208) arranged in the scale column cavity (204) and used for fixing the rotating visual target disc (203) in a mode of clamping the lighting unit (3), and a pushing column portion (207) arranged on the scale column (201) and used for keeping the clamping state of the positioning block portion (208).

2. The portable handheld vision tester as set forth in claim 1, characterized in that the push column portion (207) includes a push column (207 a) connected to the positioning block portion (208) and penetrating outward in the tip hole (205), a push column engagement box (207 b) provided on the scale column (201) and used for mounting the push column (207 a), two push column second holes (207 c) provided on the push column engagement box (207 b) and used for mounting the push column (207 a), a stopper groove (207 d) provided in the push column engagement box (207 b) and located on the push column (207 a), a stopper (207 e) provided in the stopper groove (207 d), a stopper shutter (207 f) provided at one end of the stopper (207 e) and located in the stopper groove (207 d), a stopper ring (207 g) provided at the opening of the stopper groove (207 d) and used for blocking the stopper shutter (207 f), and a stopper tension spring (207 g) provided on the stopper groove (207 f) and the stopper shutter (207 e).

3. The portable hand-held vision tester according to claim 2, wherein the positioning block portion (208) includes a positioning box (208 a) provided on an inner side surface of the scale column cavity (204), a pushing column third hole (208 b) provided on the positioning box (208 a) for mounting the pushing column (207 a), a spring mounting cylinder (208 c) provided on an inner side wall of the positioning box (208 a), a pushing column spring (208 d) provided in the spring mounting cylinder (208 c) and in contact with the pushing column (207 a), a pushing column plate (208 e) provided on the pushing column (207 a) and located in the positioning box (208 a), a sliding column (208 f) provided on the pushing column plate (208 e), a rotating ring (208 g) provided in the positioning box (208 a), a rotating ring column (208 h) provided on an inner side surface of the positioning box (208 a) and for mounting the rotating ring (208 g), a positioning block (208 n) provided on the rotating ring (208 g) and a groove (208 f), a positioning block (208 n) provided on the rotating ring (208 f), and a positioning block spring (208 q) sleeved on the positioning block (208 n).

4. A portable hand-held vision testing apparatus according to claim 3, wherein the positioning block portion (208) further comprises a roller column (208 r) provided on the positioning block (208 n), and a roller (208 s) mounted on the roller column (208 r).

5. A portable hand-held vision tester as claimed in claim 3, wherein the lighting unit (3) includes a slide cylinder (301) for mounting the optotype plate (203), a mounting ring (302) provided on the slide cylinder (301), an internal thread groove (303) provided on the slide cylinder (301), an internal thread hole (304) provided on the mounting ring (302), a bolt (305) screwed on the internal thread groove (303), the internal thread hole (304), a positioning groove (306) provided on the mounting ring (302) for engaging the positioning block (208 n), and a slide block (307) provided on the slide cylinder (301) and mounted on the slide groove (105).

6. The portable handheld vision tester as recited in claim 5, characterized in that said lighting unit (3) further comprises a detection hole (308) provided on said sliding cylinder (301), and a lighting lamp (309) provided below said detection hole (308) and connected to said power-on button (104) by a wire.

7. A portable hand-held vision tester according to claim 1, characterized in that the body unit (1) further comprises a direction indicator (112) arranged on the bottom edge of the body sleeve (101), the adjustment column unit (2) further comprising an arrow indication block (209) arranged on the scale column (201) pointing towards the direction indicator (112).