Patent EA-003867-B1 (EA)
Title: Density detection device for tasting article or component thereof
Inventor: KIDA SHINZO
IPC: G01N21/359
Filed: 2000-10-25
Abstract: 1. An apparatus directed to optically check the density of the small pieces as a test target a rod-like flavor-tasting article, comprising: a first light source configured to emit a first light beam formed of light with a first wavelength not substantially transmitted through the small pieces; a second light source configured to emit a second light beam formed of light with a second wavelength substantially transmitted through the small pieces; an optical system configured to synthesize the first and second light beams and to irradiate the test target with an obtained synthetic light beam; a first measurement unit configured to measure first and second projected light quantities respectively corresponding to the first and second light beams included in the synthetic light beam before applied to the test target; a second measurement unit configured to measure first and second reflected light quantities respectively corresponding to the first and second light beams included in the synthetic light beam reflected by a surface of the test target; a third measurement unit configured to measure first and second passing light quantities respectively corresponding to the first and second light beams included in the synthetic light beam passing through the test target; and an arithmetic circuit configured to calculate a transmitted light quantity of the second light beam transmitted through the small pieces on the basis of the first and second projected light quantities, first and second reflected light quantities, and first and second passing light quantities, and to calculate the density of the small pieces on the basis of the transmitted light quantity. 2. The apparatus according to claim 1, wherein the second measurement unit measures the first and second reflected light quantities. 3. The apparatus according to claim 1, wherein the second measurement unit measures one of the first and second reflected light quantities included in the synthetic light beam reflected by the surface of the test target, and measures the other one of the first and second reflected light quantities by calculation with a premise that the other one of the first and second reflected light quantities can be obtained with the same reflectance as that of one of the reflected light quantities. 4. The apparatus according to any one of claims 1 to 3, further comprising a detection circuit configured to calculate a fluctuation value as a difference between a reference value representing the density of the small pieces and a measurement value of the density of the small pieces which is obtained by the arithmetic circuit, and a control circuit configured to control an amount of the small pieces to be introduced into the test target in a manufacturing system for the test target on the basis of the fluctuation value. 5. The apparatus according to claim 4, further comprising an integrating circuit configured to calculate an average value of fluctuation values of a plurality of test targets obtained with the detection circuit and to transmit the average value to the control circuit. 6. The apparatus according to claim 4 or 5, further comprising a comparative determination circuit configured to compare the fluctuation value and a threshold value and to determine whether the test target is defective or not. 7. The apparatus according to any one of claims 1 to 6, wherein the small pieces are shredded leaf tobacco, and the first and second wavelengths are 0.5 mum to 0.8 mum and 1.2 mum to 1.4 mum, respectively. 8. The apparatus according to any one of claims 1 to 7, wherein each of the first and second light beams comprises a laser light beam. 9. The apparatus according to claim 8, wherein at least one of the first to third measurement units has a composite light-receiving element configured to receive and detect the first and second light beams on one optical path. 10. The apparatus according to any one of claims 1 to 10, wherein the first measurement unit measures the first and second projected light quantities by receiving and detecting the first and second light beams included in a beam portion separated from the synthetic light beam between the optical system and the test target. 11. The apparatus according to any one of claims 1 to 11, further comprising a mirror, which is disposed between the optical system and the test target, and has a mirror surface facing the test target to be inclined with respect thereto and a hole matching with an optical axis of the optical system, wherein the synthetic light beam from the optical system passes through the hole as a convergent light beam with a focal point falling on the hole and is thereafter applied to the test target, and the synthetic light beam reflected by the surface of the test target is reflected by the mirror and is introduced to the second measurement unit.