Image pickup apparatus

• US 6,985,170 B1
• Filed: 10/29/1999
• Issued: 01/10/2006
• Est. Priority Date: 10/29/1998
• Status: Expired due to Fees

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: Tsuyuki, Hiroshi
• Primary Examiner(s): Vo, Tung
• Application Number:
  US09/430,074
• Time in Patent Office: 2,265 Days
• Field of Search: 348/42, 348 43- 47, 348 62- 92, 600/101, 600/102, 600/103, 600/160, 600/104, 600109-112, 600/129, 600/167, 600/168, 600170-182, 359/368, 359/385, 359/389, 362/293, 362/574, 358/98, 606/10
• US Class Current: 348/65
• CPC Class Codes: A61B 1/00163 Optical arrangements A61B1/002, A61B1/06 take precedence
• CPC Class Codes: A61B 1/042 characterised by a proximal camera, e.g. a CCD camera
• CPC Class Codes: G02B 23/243 Objectives for endoscopes
• CPC Class Codes: G02B 5/223 containing organic substances, e.g. dyes, inks or pigments
• CPC Class Codes: H04N 23/555 for picking-up images in sites, inaccessible due to their dimensions or hazardous conditions, e.g. endoscopes or borescopes
• CPC Class Codes: H04N 25/136 using complementary colours

Abstract

An image pickup apparatus comprising an optical element which absorbs rays having specific wavelengths, an optical element which reflects rays having specific wavelengths and an organic color mosaic filter, wherein a total spectral characteristic of the optical elements satisfies the following condition:
0.45≦|ΔT/ΔW|≦0.75.

Claims

1. An image pickup apparatus comprising:

an image pickup device which comprises an optical element absorbing rays having specific wavelengths, a second optical element reflecting rays having specific wavelengths and an image pickup device having an organic color mosaic filter,

wherein a total spectral characteristic of a combination of said optical element absorbing the rays having the specific wavelengths and said optical element reflecting the rays having the specific wavelengths satisfies the following condition (1);

0.45≦

|Δ

T/Δ

W|≦

0.75 

 

(1)

wherein the reference symbol Δ

T is given by an equation shown below when transmittance at a wavelength of 550 nm is represented by T(550) and transmittance at a wavelength of 600 nm is designated by T(600),

Δ

T=T (600)−

T (550), and

the reference symbol Δ

W denotes 50 nm.

2. The image pickup system according to claim 1 comprising another optical element which has a spectral characteristic different from that of said second optical element and reflects rays having specific wavelengths, wherein said another optical element has transmittance not higher than 10% at wavelengths of 1060±

20 nm.

3. The image pickup apparatus according to claim 2 satisfying the following condition (2):

θ

(LD)<

θ

(Y) 

 

(2)

wherein the reference symbol θ

(LD) represents an inclination angle of a ray incident on said another optical element which reflects the rays having the specific wavelengths and the reference symbol θ

(Y) designates an inclination angle of a ray incident on said another optical element which reflects the rays having the specific wavelengths.

4. The image pickup apparatus according to claim 3, further satisfying the following condition (3):

θ

(LD)<

θ

(Y)≦

25°

 

 

(3).

5. The image pickup apparatus according to claim 2, 3 or 4 comprising an optical element disposed in place of said optical element which reflects the rays having the specific wavelengths, wherein said optical element absorbs rays having specific wavelengths and has a spectral characteristic different from that of said optical element which absorbs the rays having the specific wavelengths.

6. The image pickup apparatus according to claim 5, wherein said another optical element which absorbs the rays having the specific wavelengths is configured as a sealing member for the image pickup device.

7. The image pickup apparatus according to claim 1, wherein a cutoff wavelength at which at least one of the optical elements reflecting the rays having the specific wavelengths has transmittance not higher than 10% exists within a wavelength region from 610 to 650 nm, and said image pickup apparatus has transmittance not lower than 50% at a wavelength of 610 nm and transmittance not higher than 10% at a wavelength of 650 mm.

8. The image pickup apparatus according to claim 1, wherein the optical element which absorbs the rays having the specific wavelength is manufactured by a sol-gel method.

9. An endoscope system comprising:

a set of a plurality of endoscopes;

a camera control unit;

a light source unit; and

a monitor,

wherein each endoscope of said plurality of endoscopes comprises;

an objective lens system;

a filter; and

an image pickup device;

wherein at least one of said plurality of endoscopes is equipped with the objective lens system, the filter and the image pickup device, at a tip of an insert section,

wherein said plurality of endoscopes are selectively connected to said camera control unit,

wherein an object is irradiated with rays emitted from said light source unit,

wherein said monitor displays an image formed by an endoscope which is connected to said camera control unit,

wherein a spectral characteristic of the image pickup device of one of said endoscopes is different from spectral characteristics of the image pickup device of the other endoscopes,

wherein the filter of each endoscope is at least one of an optical element which absorbs rays and an optical element which reflects rays, and

wherein a total spectral characteristic of said image pickup device and said optical element is predetermined for each of said endoscopes.

10. The endoscope system according to claim 9, wherein said filters used in said plurality of endoscopes have thicknesses which are different dependently on said endoscopes.

11. The endoscope system according to claim 9, wherein said camera control unit comprises a plurality of color matrices, and has a function to select one of the color matrices for each endoscope to which a color matrix circuit of the control unit so that color reproducibilities are nearly constant on said TV monitor when said plurality of endoscopes are connected to said camera control unit.

12. An endoscope system comprising:

a set of a plurality of endoscopes;

a camera control unit;

a light source unit; and

a monitor,

wherein each endoscope of said plurality of endoscopes comprises;

an objective lens system;

a filter; and

an image pickup device;

wherein at least one of said plurality of endoscopes is equipped with the objective lens system, the filter and the image pickup device, at a tip of an insert section,

wherein said plurality of endoscopes are selectively connected to said camera control unit,

wherein an object is irradiated with rays emitted from said light source unit,

wherein said monitor displays an image formed by an endoscope which is connected to said camera control unit,

wherein a spectral characteristic of the image pickup device of one of said endoscopes is different from spectral characteristics of the image pickup device of the other endoscopes,

wherein the filter of each endoscope is at least one of an optical element which absorbs rays and an optical element which reflects rays, and

wherein a total spectral characteristic of said image pickup device and said optical element is predetermined for each of said endoscopes,

wherein the total spectral characteristic of said optical elements of each endoscope satisfies the following condition (1)

0.45≦

|Δ

T/Δ

W|≦

0.75, 

 

(1)

wherein the reference symbol Δ

T is given by an equation shown below when transmittance at a wavelength of 550 nm is represented by T(550) and transmittance at a wavelength of 600 nm is designated by T(600),

Δ

T=T (600)−

T (550), and

the reference symbol Δ

W denotes 50 nm.

13. A composite filter comprising an optical element which absorbs rays having specific wavelengths;

and an optical element which reflects rays having specific wavelengths, wherein a total spectral characteristic of a combination of said optical elements which absorbs the rays having the specific wavelengths and said optical element which reflects the rays having the specific wavelengths has transmittance not lower than 40% at a wavelength of 600 nm, transmittance of 5% at a wavelength of 700 nm and A=|Δ

T/Δ

W|=0.6±

0.1, wherein the reference symbol Δ

T represents a difference between the transmittance T(600) at the wavelength of 600 nm and the transmittance T(550) at the wavelength of 550 nm, and the reference symbol Δ

W designates 50 nm.

14. An image pickup apparatus comprising:

an image pickup device which comprises an optical element absorbing rays having specific wavelengths, a second optical element reflecting rays having specific wavelengths and an image pickup device having an organic color mosaic filter,

wherein a total spectral characteristic of a combination of said optical element absorbing the rays having the specific wavelengths and said optical element reflecting the rays having the specific wavelengths satisfies the following condition (1—

1);

0.35≦

A≦

0.75 

 

(1—

1)

wherein A=|Δ

T/Δ

W| and the reference symbol Δ

T is given by an equation shown below when transmittance at a wavelength of 550 nm is represented by T(550) and transmittance at a wavelength of 600 nm is designated by T(600), Δ

T=T (600)−

T (550), and the reference symbol Δ

W denotes 50 nm.