TW201447413A - Lens unit and camera device - Google Patents

Abstract

The invention provides a lens unit and a camera device which can ensure high precision assembly, raise productivity and restrain unnecessary light and generation of eidolon and light pots. In a lens unit with at least four lenses with flanges, a formula (1) is satisfied and thud the area of an abutting area of a lens is not large so as to restrain surface pressure and maintain lens shapes with good precision; the external diameter of a visor can not be too small so as to effectively restrain unnecessary light. A formula (3) is satisfied so as to raise lens shaping performance and realize low height of a lens unit. The formula (1) is 0.25 ≤ L-A ≤ 1.0, and the formula (3) is 0.5 ≤ t/t 0 ≤ 1.5, wherein A (mm) represents the external diameter of a visor, L (mm) represents a largest diameter of an abutting area of a projecting part of a lens of a visor, t (mm) represents an optical axis direction distance between adjacent visors, and t0 (mm) represents an axial thickness of the lens clamped by visors.

Description

Lens unit and camera

The present invention relates to a lens unit and an image pickup apparatus which are preferably used in an image pickup apparatus having a solid-state image sensor such as a CCD image detector or a CMOS image detector.

In recent years, portable information terminals and mobile phones, which are called PDAs (Personal Digital Assistants), have become popular, and many of them are equipped with imaging devices such as digital cameras. In this imaging apparatus, there is a need to realize an optical system that can correspond to a high number of pixels of millions of pixels, and on the other hand, there is an increasing demand for miniaturization, thinning, and weight reduction of a device. In addition, the optical device using a plurality of lenses is also required to have high performance and size reduction, and the demand for shortening of the tact time during manufacture is gradually increasing. An optical system that satisfies such a requirement has been proposed as a lens-fit type lens unit in which a light shielding plate is held inside as disclosed in Patent Document 1.

In the conventional example shown in Fig. 8 of Patent Document 1, the relative positions between the lenses are made high by abutting the flange portions of the lenses. Ground adjustment makes assembly adjustment easy. Unwanted light is blocked by providing a light shielding plate between the lenses.

[Practical Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-251402

However, if the flange portions of the lenses are directly in contact with each other, unnecessary light may be transmitted through the abutting faces of the flange portions. However, in Reference 1, the countermeasure against such unnecessary light is not mentioned at all.

The present invention has been made in view of the above problems, and an object thereof is to provide a lens unit and an image pickup apparatus capable of ensuring high-precision assembly and productivity improvement, suppressing unnecessary light, and suppressing occurrence of ghosts and flares.

In the lens unit of the present invention, in the lens unit having four or more lenses provided with the flange portion, the flange portion of at least three lenses disposed from the object side is formed to protrude in the optical axis direction. The portion is assembled by abutting the protruding portion with the flange portion of the adjacent lens, and a light shielding plate is disposed on the inner side in the direction perpendicular to the optical axis of the protruding portion, and satisfies the following formula; LA≦1.0...(1), 0.5≦t/t0≦1.5 (3), but A (mm): the outer diameter of the light shielding plate, L (mm): the maximum diameter of the abutting surface of the protruding portion of the lens held by the light shielding plate , t (mm): optical axis direction distance between the adjacent light shielding plates, t0 (mm): the on-axis thickness of the aforementioned lens held by the light shielding plate.

In the lens unit in which the imaging device is high in image quality and miniaturized, it is necessary to have four or more lenses that appear to be opposite in the optical axis direction. However, when four or more lenses are stacked, the errors in the design specifications may increase due to the accumulation of component errors and assembly errors in the optical axis direction and the vertical direction. Here, when the flange portions of the lenses are directly in contact with each other, the assembly error of the lens unit can be reduced. However, since there is no light shielding plate or the like therebetween, unnecessary light may be transmitted through the abutting surface. In particular, with miniaturization, since reflection in the inner surface of the lens barrel adversely affects imaging performance, the problem of unnecessary light becomes larger.

In view of the above, in the present invention, the light shielding plate is disposed on the inner side in the direction perpendicular to the optical axis of the protruding portion of the lens, and the unnecessary light passing through the inner side of the protruding portion in the direction perpendicular to the optical axis is shielded from light. However, if the area of the protruding portion is too large, unnecessary light may be transmitted through the lens unit and the abutting surface of the protruding portion, and if the outer diameter of the light shielding plate is too large, the protruding portion may be protruded. The area of the part is too small, and the surface pressure during assembly will increase, which will The optical surface adjacent to the abutting portion is deformed, and the stability of assembly may be insufficient. In the present invention, the outer diameter of the light shielding plate is set to A (mm), and when the maximum diameter of the abutting surface of the protruding portion of the lens that holds the light shielding plate is set to L (mm), Satisfy the formula (1). When the value of the formula (1) is equal to or greater than the lower limit value, the area of the abutting surface of the protruding portion does not become too large, and the surface pressure can be suppressed and the lens shape with good assembly accuracy can be maintained. On the other hand, when the value of the formula (1) is equal to or less than the upper limit value, the outer diameter of the light shielding plate is not too small, and the suppression of unnecessary light can be effectively performed.

When the value of the formula (3) is equal to or greater than the lower limit value, the flange portion is not excessively thin, and when the lens is formed by injection molding, the flow of the resin flowing in from the shutter is less likely to be hindered, and the moldability can be improved. On the other hand, when the value of the formula (3) is equal to or less than the upper limit value, the flange portion is not excessively thick, and the thickness of the lens unit can be reduced.

An image pickup device of the present invention includes the lens unit and a solid-state image sensor.

According to the present invention, it is possible to provide a lens unit and an image pickup device which can ensure high-precision assembly and productivity improvement, suppress unnecessary light, and suppress generation of ghosts and spots.

AP1~AP5‧‧‧ visor

L1~L6‧‧ lens

10‧‧‧ camera

11‧‧‧Photographic components

11a‧‧‧Photoelectric Conversion Department

11b‧‧‧ wafer

11c‧‧‧Wire

12‧‧‧ camera lens

13‧‧‧Mirror tube

13a‧‧‧ wall

13b‧‧‧Little Trails Department

14‧‧‧Anti-infrared filter

15‧‧‧Actuator

15a‧‧‧Vector

15b‧‧‧ coil

15c‧‧‧ magnet

15d‧‧‧ yoke

16‧‧‧ circuit board

17‧‧‧ pedestal components

17a‧‧‧ Sidewall

17b‧‧‧Upper wall

17c‧‧‧ openings

60‧‧‧Input button

65‧‧‧Display Department

70‧‧‧ touch panel

71‧‧‧Shutter button

80‧‧‧Wireless Communications Department

92‧‧‧Memory Department

100‧‧‧Smart Phone

101‧‧‧Control Department

[Fig. 1] A cross-sectional view along the optical axis of the image pickup apparatus 10 of the present embodiment.

[Fig. 2] shows a cross-sectional view in which only the lens unit of the five spherical lenses of Fig. 1 is exploded.

[Fig. 3] A view in which the arrow III portion of Fig. 2 is enlarged and displayed.

[Fig. 4] Front view (a) and rear view (b) of the smartphone equipped with the imaging device 10.

[Fig. 5] The control block diagram of the smart phone of Fig. 4.

[Fig. 6] A cross-sectional view of a lens unit of an embodiment of four spherical lenses.

[Fig. 7] A cross-sectional view of a lens unit of an embodiment of six spherical lenses.

Hereinafter, embodiments of the invention will be described with reference to the drawings. Fig. 1 is a cross-sectional view along the optical axis of the image pickup apparatus 10 of the present embodiment. The configuration shown below is only a schematic view, and the shape, size, and the like are different from actual ones.

As shown in Fig. 1, the imaging device 10 includes a CMOS image sensor 11 as a solid-state image sensor including a photoelectric conversion unit (light-receiving surface) 11a, and a photoelectric conversion unit 11a of the image sensor 11; The imaging lens 12 for imaging, the lens barrel 13 for holding the imaging lens 12, the anti-infrared filter 14 having a parallel flat plate shape, the actuator 15 for driving the imaging lens 12, and the circuit for mounting the imaging element 11 The substrate 16 and the pedestal member 17 that holds the imaging lens 12 and the actuator 15 are provided.

As shown in Fig. 1, the imaging element 11 is formed on the light-receiving side (on the upper side of the first drawing) of the wafer 11b having a parallel flat shape, and the pixels (photoelectric conversion elements) are arranged in two dimensions. A signal processing circuit (not shown) is formed around the photoelectric conversion portion 11a of the imaging surface. The signal processing circuit is a driving circuit unit that sequentially drives each pixel to obtain a signal charge, an A/D conversion unit that converts each signal charge into a digital signal, and uses the digital signal to form an image signal output. The signal processing unit and the like are configured.

Further, a plurality of pads (not shown) formed in the vicinity of the outer edge of the light receiving surface side of the wafer 11b of the image sensor 11 are connected to the circuit board 16 by the electric wires 11c.

The pedestal member 17 integrally molded of the resin is a frame shape in which a square body is integrally formed, and has four side wall portions 17a that are provided to surround the image sensor 11 and an upper wall portion 17b that intersects the upper end thereof. A rectangular opening 17c is formed in the center of the upper wall portion 17b, and the anti-infrared filter 14 is attached to the upper wall portion 17b so as to cover the opening 17c.

The image sensor 11 is an image signal for converting the signal charge from the photoelectric conversion unit 11a into a digital YUV signal or the like, and is transmitted from the electric wire 11c to the external circuit (not shown) from the wiring pattern of the circuit board 16 (for example, a camera is attached). The control circuit of the upper device of the module is sent. Moreover, the electric power and the pulse signal for driving the image sensor 11 from the external circuit may be received from the wiring pattern of the circuit board 16 through the electric wire 11c. Here, Y is a luminance signal, U (=R-Y) is a color difference signal of red and luminance signals, and V (=B-Y) is a color difference signal of blue and luminance signals. number. Further, the imaging element is not limited to the above-described CMOS image detector, and may be used by others such as a CCD.

In Fig. 1, an imaging lens 12 is provided inside the lens barrel 13. The imaging lens 12 is composed of a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5 which are disposed in order from the object side, and each has a flange outside the effective diameter. unit.

Fig. 2 is a cross-sectional view showing only the lens unit of Fig. 1 exploded. The image side surface L1f1 of the flange portion L1f of the first lens L1 is formed so as to protrude toward the image side, and is in surface contact with the object side surface L2f2 of the flange portion L2f of the second lens L2 that is moved toward the image side. The adhesive which has been mixed in the light absorbing material may be applied between the image side surface L1f1 and the object side surface L2f2. A donut plate-shaped first light blocking plate AP1 is disposed on the inner side of the protruding portion of the flange portion L1f of the first lens L1 in the direction perpendicular to the optical axis. The first light blocking plate AP1 has a function of shielding light rays that pass outside the effective diameter of the first lens L1. Further, the optical axis alignment of the lenses L1 and L2 may be performed by fitting the flange inner circumferential surface L1f3 connected to the image side surface L1f1 and the flange outer circumferential surface L2f4 connected to the object side surface L2f2.

In the second figure, the image side surface L2f1 of the flange portion L2f of the second lens L2 is a projection portion that protrudes toward the image side, and the object side surface L3f2 that moves toward the image side in the flange portion L3f of the third lens L3. Face contact. The adhesive which has been mixed in the light absorbing material may be applied between the image side surface L2f1 and the object side surface L3f2. A dope plate-shaped second light blocking plate AP2 is disposed on the inner side in the direction perpendicular to the optical axis of the protruding portion of the flange portion L2f of the second lens L2. The second visor AP2 has a second lens to pass through L2's function of light blocking outside the effective path. Further, the optical axis alignment of the lenses L2 and L3 may be performed by fitting the flange inner circumferential surface L2f3 connected to the image side surface L2f1 and the flange outer circumferential surface L3f4 connected to the object side surface L3f2.

In the second figure, the image side surface L3f1 of the flange portion L3f of the third lens L3 is a projection portion that protrudes toward the image side, and the object side surface L4f2 that moves toward the image side in the flange portion L4f of the fourth lens L4. Face contact. The adhesive which has been mixed in the light absorbing material may be applied between the image side surface L3f1 and the object side surface L4f2. In the flange portion L3f of the third lens L3, the third light-shielding plate AP3 having a doughnut plate shape is disposed on the inner side in the direction perpendicular to the optical axis of the protruding portion. The third light blocking plate AP3 has a function of shielding light rays that pass outside the effective diameter of the third lens L3. Further, the optical axis alignment of the lenses L3 and L4 may be performed by fitting the flange inner circumferential surface L3f3 connected to the image side surface L3f1 and the flange outer circumferential surface L4f4 connected to the object side surface L4f2.

Between the image side surface L4f1 of the flange portion L4f of the fourth lens L4 and the object side surface L5f2 of the flange portion of the fifth lens L5, the dowel plate-shaped fourth light shielding plate (large diameter light shielding plate) AP4 is abutted. Grounding is held. The outer periphery of the fourth light blocking plate AP4 is in contact with the inner circumference of the lens barrel 13, and its inner circumference protrudes inward in the direction perpendicular to the optical axis in a cantilever shape.

Fig. 3 is a view showing an enlarged view of an arrow III portion of Fig. 2; In the third drawing, the outer diameter of the first light blocking plate AP1 is set to Aa (mm), and the maximum diameter of the abutting surface of the image side surface L1f1 and the object side surface L2f2 of the lenses L1 and L2 of the first light blocking plate AP1 is sandwiched. Set to La (mm), the following formula is established.

0.4≦La-Aa≦1.0...(1A)

Moreover, the outer diameter of the second light-shielding plate AP2 is set to Ab (mm), and the maximum diameter of the contact surface of the image side surface L2f1 and the object side surface L3f2 in the lenses L2 and L3 of the second light-shielding plate AP2 is set to Lb ( In the case of mm, the following formula is established.

0.4≦Lb-Ab≦1.0...(1B)

The optical axis direction distance between the first light-shielding plate AP1 and the second light-shielding plate AP2 is set to t2 (mm), and the on-axis thickness of the second lens L2 held by the first light-shielding plate AP1 and the second light-shielding plate AP2 is set. When t02 (mm) is set, the following formula is established.

0.5t02≦t2≦1.5t02...(3A)

Moreover, the outer diameter of the third light-shielding plate AP3 is set to Ac (mm), and the maximum diameter of the contact surface of the image side surface L3f1 and the object side surface L4f2 in the lenses L3 and L4 of the third light-shielding plate AP3 is set to Lc ( In the case of mm, the following formula is established.

0.4≦Lc-Ac≦1.0...(1C)

The optical axis direction distance between the second light blocking plate AP2 and the third light blocking plate AP3 is set to t3 (mm), and the on-axis thickness of the third lens L3 held by the second light blocking plate AP2 and the third light blocking plate AP3 is set. When t03 (mm) is set, the following formula is established.

0.5t03≦t3≦1.5t03...(3B)

In Fig. 2, the flange portion L5f of the fifth lens L5 disposed on the most image side and the fourth lens adjacent to the fifth lens L5 are provided. The outer diameter of the fourth light blocking plate AP4 between the flange portions L4f of L4 is set to B (mm), and the maximum diameter of the abutting surface of the lenses L4 and L5 holding the fourth light blocking plate AP4 is set to L (mm). In the case, the following formula is established.

L≦B...(2)

In this way, since the equations (1A) to (1C) are satisfied, the area of the abutting surface of the lens does not become too large, and the surface pressure can be suppressed and the lens shape with high precision can be maintained, and the outer diameters of the visors AP1 to AP3 can be maintained. It does not become too small, and the suppression of unnecessary light can be effectively performed. Further, any one of the formulas (1A) to (1C) may be satisfied.

In the first drawing, the object side surface L1f2 of the flange portion L1f of the first lens L1 is in contact with the image side surface of the wall portion 13a having the aperture stop S of the lens barrel 13, and the outer circumferential surface L1f4 of the flange portion L1f is The inner circumferential surface of the small diameter portion 13b adjacent to the wall portion 13a is in contact with each other. On the other hand, the outer peripheral surface of the flange portion L5f of the fifth lens L5 is adjacent to the fourth light blocking plate AP4 and is in contact with the inner circumferential surface of the lens barrel 13.

The flange portion of each lens is formed with high precision by injection molding. Therefore, at the time of assembly, the lens barrel 13 includes the first lens L1, the first light blocking plate AP1, the second lens L2, the second light blocking plate AP2, the third lens L3, the third light blocking plate AP3, and the fourth lens L4. When assembled, the flange portions are in contact with each other, and the relative position in the optical axis direction from the first lens L1 to the fourth lens L4 can be accurately adjusted. In addition, since the thickness of the fourth light-shielding plate AP4 is managed with high precision, when the fifth lens L5 is assembled in this manner, the optical directions of the fourth lens L4 and the fifth lens L5 are in the optical axis direction. The relative position can be adjusted with high precision.

On the other hand, the flange portions are in contact with each other, and as shown in Fig. 2, the optical axes from the first lens L1 to the fourth lens L4 are accurately matched. Further, the first lens L1 and the fifth lens L5 are transmitted through the lens barrel 13 so that the optical axes thereof are excellent in accuracy. After the fifth lens L5 is inserted, the fifth lens L5 is fixed to the lens barrel 13 by the adhesive BD applied to the image pickup element 11 side of the flange portion L5f.

The actuator 15 is a cylindrical carrier 15a that is screwed into the lens barrel 13, a coil 15b that is attached to the carrier 15a and extends in the optical axis direction, and a magnet 15c that is disposed to oppose the coil 15b. The frame-shaped yoke 15d supported by the magnet 15c is constituted. The coil 15b is connected to an external circuit through a wiring (not shown). The lower end of the yoke 15d is adhered to the upper wall portion 17b of the pedestal member 17. Further, the carrier 15a is urged in the direction of the imaging element 11 by an elastic member (not shown).

The operation of the imaging device 10 described above will be described. Fig. 4 (a) and (b) show a state in which the image pickup apparatus 10 is equipped in the smartphone 100 as a portable terminal. Moreover, FIG. 5 is a control block diagram of the smartphone 100.

In the imaging device 10, for example, the object-side end surface of the lens barrel 13 is provided on the back surface of the smartphone 100 (refer to FIG. 4(b)), and is disposed at a position corresponding to the lower side of the liquid crystal display unit.

The imaging device 10 is connected to the control unit 101 of the smartphone 100 via an external connection terminal (the portion indicated by an arrow in FIG. 5), and outputs an image signal such as a luminance signal and a color difference signal to the control unit 101 side.

On the other hand, as shown in FIG. 5, the smart phone 100 includes a control unit (CPU) 101 that controls each unit in a unified manner and executes a program corresponding to each process; and switches and numbers such as a power source are used. The touch panel indicates an input unit 60 for input; and a display unit 65 that displays an image or the like that is imaged by the liquid crystal panel in addition to predetermined data (however, the liquid crystal panel of the display unit and the touch panel of the input unit are touch panels 70) A wireless communication unit 80 for realizing various kinds of information communication with an external server; and a memory unit for storing data of a system program of the smartphone 100, various processing programs, and end IDs (ROM) And a temporary storage unit (RAM) 92 as a work area temporarily accommodated in accordance with various processing programs and materials executed by the control unit 101, processing data, or image data obtained by the imaging device 10. .

In the smartphone 100, by the operation of the input button unit 60, the image pickup lens 12 is driven to perform an autofocus operation by an actuator (not shown), and the shutter button 71 or the like is pressed to move the image pickup device. 10 actions to make a picture. The image signal input from the image pickup device 10 is stored in the memory unit 92 by the control system of the smart phone 100, or is displayed by the touch panel 70, and further transmitted to the outside through the wireless communication unit 80 as image information. Was sent.

Fig. 6 is a cross-sectional view showing a lens unit of an embodiment of four spherical lenses. In the sixth aspect, the image side surface L1f1 of the flange portion L1f of the first lens L1 is a projecting portion that protrudes toward the image side, and the object side surface L2f2 that moves toward the image side in the flange portion L2f of the second lens L2. Face contact. Between the image side L1f1 and the object side L2f2, the light absorption has been mixed The adhesive applied to the material can also be applied. A donut plate-shaped first light blocking plate AP1 is disposed on the inner side of the protruding portion of the flange portion L1f of the first lens L1 in the direction perpendicular to the optical axis. The first light blocking plate AP1 has a function of shielding light rays that pass outside the effective diameter of the first lens L1. Further, the optical axis alignment of the lenses L1 and L2 may be performed by fitting the flange inner circumferential surface L1f3 connected to the image side surface L1f1 and the flange outer circumferential surface L2f4 connected to the object side surface L2f2.

In the sixth embodiment, the image side surface L2f1 of the flange portion L2f of the second lens L2 is a projection portion that protrudes toward the image side, and the object side surface L3f2 that moves toward the image side in the flange portion L3f of the third lens L3. Face contact. The adhesive which has been mixed in the light absorbing material may be applied between the image side surface L2f1 and the object side surface L3f2. A dope plate-shaped second light blocking plate AP2 is disposed on the inner side in the direction perpendicular to the optical axis of the protruding portion of the flange portion L2f of the second lens L2. The second light blocking plate AP2 has a function of shielding light rays that pass outside the effective diameter of the second lens L2. Further, the optical axis alignment of the lenses L2 and L3 may be performed by fitting the flange inner circumferential surface L2f3 connected to the image side surface L2f1 and the flange outer circumferential surface L3f4 connected to the object side surface L3f2.

Between the image side surface L3f1 of the flange portion L3f of the third lens L3 and the object side surface L4f2 of the flange portion of the fourth lens L4, the dowel plate-shaped third light shielding plate (large diameter light shielding plate) AP3 is abutted. Grounding is held. The outer periphery of the third light blocking plate AP3 is in contact with the inner circumference of the lens barrel 13. In the present embodiment, the light shielding plate satisfying the formula (1) is the first light shielding plates AP1 and AP2, and the light shielding plate satisfying the formula (2) is the third light shielding plate AP3. Other than The configuration is the same as that of the above embodiment.

Fig. 7 is a cross-sectional view showing a lens unit of an embodiment of six spherical lenses. In Fig. 7, the image side surface L1f1 of the flange portion L1f of the first lens L1 is a projection portion that protrudes toward the image side, and the object side surface L2f2 that moves toward the image side in the flange portion L2f of the second lens L2. Face contact. The adhesive which has been mixed in the light absorbing material may be applied between the image side surface L1f1 and the object side surface L2f2. A donut plate-shaped first light blocking plate AP1 is disposed on the inner side of the protruding portion of the flange portion L1f of the first lens L1 in the direction perpendicular to the optical axis. The first light blocking plate AP1 has a function of shielding light rays that pass outside the effective diameter of the first lens L1. Further, the optical axis alignment of the lenses L1 and L2 may be performed by fitting the flange inner circumferential surface L1f3 connected to the image side surface L1f1 and the flange outer circumferential surface L2f4 connected to the object side surface L2f2.

In Fig. 7, the image side surface L2f1 of the flange portion L2f of the second lens L2 is a projection portion that protrudes toward the image side, and the object side surface L3f2 that moves toward the image side in the flange portion L3f of the third lens L3. Face contact. The adhesive which has been mixed in the light absorbing material may be applied between the image side surface L2f1 and the object side surface L3f2. A dope plate-shaped second light blocking plate AP2 is disposed on the inner side in the direction perpendicular to the optical axis of the protruding portion of the flange portion L2f of the second lens L2. The second light blocking plate AP2 has a function of shielding light rays that pass outside the effective diameter of the second lens L2. Further, the optical axis alignment of the lenses L2 and L3 may be performed by fitting the flange inner circumferential surface L2f3 connected to the image side surface L2f1 and the flange outer circumferential surface L3f4 connected to the object side surface L3f2.

In Fig. 7, the image side surface L3f1 of the flange portion L3f of the third lens L3 is a projection portion that protrudes toward the image side, and the object side surface L4f2 that moves toward the image side in the flange portion L4f of the fourth lens L4. Face contact. The adhesive which has been mixed in the light absorbing material may be applied between the image side surface L3f1 and the object side surface L4f2. In the flange portion L3f of the third lens L3, the third light-shielding plate AP3 having a doughnut plate shape is disposed on the inner side in the direction perpendicular to the optical axis of the protruding portion. The third light blocking plate AP3 has a function of shielding light rays that pass outside the effective diameter of the third lens L3. Further, the optical axis alignment of the lenses L3 and L4 may be performed by fitting the flange inner circumferential surface L3f3 connected to the image side surface L3f1 and the flange outer circumferential surface L4f4 connected to the object side surface L4f2.

In Fig. 7, between the image side surface L4f1 of the flange portion L4f of the fourth lens L4 and the object side surface L5f2 of the flange portion of the fifth lens L5, the dowel plate-shaped fourth light blocking plate AP5 is abutted. Grounding is held. The outer periphery of the fourth light blocking plate AP4 is in contact with the inner circumference of the lens barrel 13.

Between the image side surface L5f1 of the flange portion L5f of the fifth lens L5 and the object side surface L6f2 of the flange portion of the sixth lens L6, the dowel plate-shaped fifth light shielding plate (large diameter light shielding plate) AP5 is abutted. Grounding is held. The outer periphery of the fifth light blocking plate AP5 is in contact with the inner circumference of the lens barrel 13. In the present embodiment, the light shielding plate satisfying the formula (1) is the first light blocking plate AP1, the second light blocking plate AP2, and the third light blocking plate AP3, and the light shielding plate satisfying the formula (2) is the fourth light shielding plate AP4. The fifth visor AP5. The other configuration is the same as that of the above embodiment.

In Table 1, L (La~) in each embodiment is shown. Le), A (Aa ~ Ae) specific values. Further, in Table 2, the distance t between the visors (t2 to t5) of each embodiment and the on-axis thickness t0 (t01 to t06) of the lens are shown. In the case of the imaging lens of the four spherical lenses, the outer diameter Ac of the light-shielding plate AP3 on the image (front) side of the fourth lens L4 is 3.44 mm, which is the value of B in the request, and the imaging lens of five spherical lenses. The outer diameter Ad=1.81 mm of the light-shielding plate AP4 on the image (front) side of the fifth lens L5 is the value of B in the request, the image pickup lens of the six spherical lenses, and the image (front) side of the sixth lens L6. The outer diameter Ae of the visor AP5 = 2.61 mm is the value of B in the request.

Since the spot intensity of the unnecessary light passing through the abutting surface is higher than that of the lens on the image side of the lens unit, the allowable range is wider from the viewpoint of reducing the spot intensity of the lens on the object side. On the other hand, the pressure applied to the abutting surface at the time of assembly does not change much regardless of the abutting surface of any of the lenses. Therefore, the inventors of the present invention changed the LA as shown in Table 3, and the LA range of the first lens L1 and the second lens L2 was the widest between the reduction of the spot intensity and the deformation of the contact surface. The influence between the first lens L1 and the second lens L2.

According to the results of Table 3, when the L-A is 1.05 mm or more, the spot intensity is too strong, but if it is smaller than 1.0 mm, the spot intensity is small, and it is confirmed that the image quality is not affected by actual use. On the other hand, when the deformation of the abutting surface is 0.22 mm or less, the deformation of the optical surface is too large, but when it is 0.25 mm or more, it is confirmed that the deformation of the optical surface is suppressed and it can be used. Therefore, it has been confirmed that there is no problem that L-A is 0.25 mm or more and 1.0 mm or less.

Hereinafter, the preferred aspects of the present embodiment will be described.

Regarding the above formula (3), it is preferable to satisfy the following formula (3').

0.5≦t/t0≦1.15...(3')

It is preferable that the protruding portion of the lens is adhered to the flange portion of the adjacent lens by an adhesive. By bonding the flange portions of the aforementioned lenses that abut each other, the bonding strength of the lens unit can be improved.

The above adhesive is preferably a material that absorbs light. Thereby, it is possible to further suppress the unnecessary light from being transmitted through the abutting surface of the flange portion of the lens. The light absorbing material is a material that blocks light by absorbing unnecessary light, for example, an inorganic pigment having black color, an organic pigment, or the like. The material having a light-shielding property by absorption, for example, has carbon fine particles, titanium fine particles, aniline fine particles, and an anthraquinone dye, but carbon fine particles such as an anthraquinone dye or titanium fine particles are preferable. The average particle diameter of the material having light blocking properties by absorption is 0.1 μm or more and 1 μm or less.

Further, when the adhesive is photocurable, it can be cured in a state of being positioned at a position between the lenses. In the adhesive, the content of the light absorbing material is preferably 5% by weight or more and 10% by weight or less. The adhesive contains a light-transmitting fine particle, and the reflectance at a wavelength of 350 nm or more and 750 nm or less is preferably 1.5% or less. The reflectance is measured by a reflectance measuring device USPM-RuIII manufactured by Olympus, for example, in the wavelength range of 350 nm to 750 nm. The fine particles may be any of an organic compound such as bridging propylene beads or an inorganic compound such as ceria, magnesium metasilicate alumina, or titanium oxide. Among them, cerium oxide is preferably used from the viewpoints of dispersibility of fine particles, low cost, and the like.

The large-diameter light shielding plate is held between the flange portion of the lens on the image side and the flange portion of the lens adjacent to the lens on the most image side, and the outer diameter of the large-diameter light shielding plate is set. In the case of B (mm), when the maximum diameter of the abutting surface of the flange portion abutting on the large-diameter light-shielding plate is set to L (mm), the following formula is preferably satisfied. Thereby, the lens unit can be miniaturized.

L≦B...(2)

It is preferable that the outer circumference of the large-diameter light-shielding plate is in contact with the inner circumference of the lens barrel that holds the lens. As described above, the lens unit can be miniaturized by abutting the flange portions of the lens, but unnecessary light may be transmitted through the abutting surface of the flange portion of the lens. In particular, in a thin lens unit, the closer the ray angle of the imaging surface to the optical axis is, the more unnecessary light that reaches the outer peripheral portion of the lens tends to become larger. Here, at the very top Between the flange portion of the lens on the image side and the flange portion of the lens adjacent to the lens on the most image side, the large-diameter light-shielding plate is held, and the outer circumference of the large-diameter light-shielding plate and the lens are When the inner circumference of the held lens barrel is in contact with each other, unnecessary light can be blocked from light before being incident on the imaging surface even if it is transmitted from the abutting surface of the flange portion of the lens that passes through the object side. Further, since the lens on the image side is relatively large in diameter, the eccentricity error sensitivity (sensitivity) is small, and high assembly precision is not required, and the flange portions are abutted until the most image side lens. It is not easy to miniaturize the lens unit, which is one of the reasons.

It is preferable to provide a light shielding plate between all the lenses. Thereby, the shading of the unnecessary light can be performed efficiently.

It is preferable that the number of the aforementioned lenses is five or six. Thereby, even if it is high in size and small, it is possible to provide a lens unit that can effectively correct aberrations.

Regarding the above formula (1), it is preferable to satisfy the following formula (1').

0.25≦L-A≦0.502...(1')

The light shielding plate is preferably a light shielding filter. Thereby, a light-shielding plate with high precision can be formed. The shading filter is a material that absorbs light outside the effective diameter of the parallel plate, and only allows the light in the effective path to pass.

The present invention is not limited to the embodiments disclosed in the specification, and other embodiments and modifications are also included, and those skilled in the art can understand the embodiments and technical ideas disclosed in the specification. E.g, It is also possible to provide a shading filter instead of the visor.

10‧‧‧ camera

11a‧‧‧Photoelectric Conversion Department

11b‧‧‧ wafer

11c‧‧‧Wire

12‧‧‧ camera lens

13‧‧‧Mirror tube

13a‧‧‧ wall

13b‧‧‧Little Trails Department

14‧‧‧Anti-infrared filter

15‧‧‧Actuator

15a‧‧‧Vector

15b‧‧‧ coil

15c‧‧‧ magnet

15d‧‧‧ yoke

16‧‧‧ circuit board

17‧‧‧ pedestal components

17a‧‧‧ Sidewall

17b‧‧‧Upper wall

17c‧‧‧ openings

AP1~AP4‧‧‧ visor

L1~L5‧‧ lens

Claims (11)

In a lens unit having four or more lenses having flange portions, the flange portion of at least three lenses arranged from the object side is a protruding portion that protrudes in the optical axis direction. The protruding portion is assembled in contact with the flange portion of the adjacent lens, and a light shielding plate is disposed on the inner side in the direction perpendicular to the optical axis of the protruding portion, and satisfies the following formula; 0.25 ≦ LA ≦ 1.0 (1), 0.5≦t/t0≦1.5 (3), but A (mm): outer diameter of the light shielding plate, L (mm): the aforementioned protrusion in the aforementioned lens held by the light shielding plate The maximum diameter of the abutting surface, t (mm): the distance in the optical axis direction between the adjacent visors, t0 (mm): the on-axis thickness of the aforementioned lens held by the visor. The lens unit of claim 1, wherein the following formula is satisfied; 0.5≦t/t0≦1.15 (3'). The lens unit according to claim 1, wherein the protruding portion of the lens is adhered to the flange portion of the adjacent lens by an adhesive. For example, the lens unit of claim 3, wherein The aforementioned adhesive is a material that absorbs light. The lens unit according to claim 1, wherein the flange portion of the lens on the most image side and the flange portion of the lens adjacent to the lens on the most image side are shielded from each other by a large diameter. In the plate, the outer diameter of the large-diameter light-shielding plate is set to B (mm), and the maximum diameter of the abutting surface of the flange portion that is in contact with the large-diameter light-shielding plate is set to L (mm), and the following is satisfied. Formula; L≦B...(2). The lens unit according to claim 5, wherein the outer circumference of the large-diameter light-shielding plate is in contact with an inner circumference of the lens barrel that holds the lens. A lens unit according to claim 1, wherein a light shielding plate is provided between all the lenses. The lens unit of claim 1, wherein the number of the lenses is five or six. The lens unit of claim 1, wherein the following formula is satisfied; 0.25 ≦ L - A ≦ 0.502 (1 '). The lens unit of claim 1, wherein the light shielding plate is a light shielding filter. An image pickup apparatus comprising: a lens unit according to claim 1 and a solid-state image sensor.