JP2874172B2 - Image reading device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a structure of an image reading apparatus used for image input.

[Conventional technology]

Conventionally, a carriage 7 including a self-scanning photoelectric converter 11 (hereinafter simply referred to as an image sensor), a lens 12, a lamp 8, and the like shown in FIG. As shown in c), it is installed with respect to the reading range 13, the pulse motor 14 is used as a driving source, and the pulley 15,
An image reading apparatus has been devised in which the carriage 7 is moved along a guide shaft 17 via a belt 16 to perform sub-scanning. As shown in FIG. 4, the image reading apparatus is installed in the scanner body 1 incorporating a transparent original plate 18 on the lower surface and a transparent original confirmation plate 19 on the upper surface, and the scanner main body 1 is arranged on the original. Then, the reflection original 20 is read. Further, a white reference tape 21 serving as a reference of the document density is attached inside the scanner main body 1 as shown in FIG. 3A, is read in advance before reading the document, and moves the carriage 7 in the B direction. The original is being read.

[Problems to be solved by the invention]

In the conventional image reading apparatus as described above, a problem generally called shading occurs. Causes of shading include variations in the luminous intensity distribution of the light source, dimming around the lens, and variations in bits of the image sensor. Further, since accurate color reproduction is required in a color image reading apparatus, it is necessary to balance white. In order to perform the above-described shading correction and white balance adjustment, it has been generally known to read a white reference original having a constant density and normalize an image signal based on the read signal before reading the image. Further, in order to effectively use the output level of the image sensor, the image sensor is adjusted so as to output the highest output when a white reference original is read.

However, since the image reading apparatus as described above is configured to read a reflective original, the shading correction, white balance adjustment, image The sensor output level was adjusted. However, when reading a transmissive original, a transmissive white reference original is required because the conditions of the light amount distribution and the absolute light amount of the lamp light source are different from those of the reflective white reference original. Further, when reading a transparent original, it is necessary to transmit the original through a lamp light source and perform reading, so that reading with a configuration in which the lamp, the image sensor, and the lens are mounted in a carriage is impossible.

[Means for solving the problem]

In order to solve the above-mentioned problem, an image reading apparatus according to the present invention includes a light source for reading a transparent document and a transparent white diffuser plate (hereinafter simply referred to as a white panel) separately from the illumination of the scanner body for the reflective document. Prepare a device, switch the reading position of the white reference for reflection and transmission, and use the white panel on the illumination device as the white reference document for the transparent document. did. Further, the illumination device for the transparent original and a circuit / power supply unit for controlling the scanner body are integrated, and the illumination / circuit /
The power supply unit is provided with means such as a switch for switching between a reflective original and a transparent original.

[Action]

The image reading apparatus configured as described above, when reading a reflected original, installs the scanner main body on the upper part of the original, uses a lamp mounted on the carriage, and sets a white reference original installed inside the scanner main body. The reading is performed after the correction according to. When reading a transparent original, the original is placed above the white panel on the illumination device for the transparent original, and the scanner body is placed above the original to perform reading. At this time, the white panel is read without using the lamp in the carriage and the white reference document of the scanner body,
The white reference is used. Further, the circuit / power supply section is separated from the scanner main body, and the circuit / power supply section and the lighting device are integrated to reduce the weight of the scanner main body. Then, when the scanner main body is installed on the upper part by the original changeover switch installed in the integrated lighting / circuit / power supply section, the lamp and the white reference original reading position are automatically switched.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, when reading a reflection original, the scanner main body 1 is arranged above the original as shown in FIG. When reading a transparent original, as shown in FIG. 1 (a), the transparent original 4 is arranged above the white panel 3 provided in the circuit / power supply unit 2, and further the scanner is placed above the transparent original 4. The main body 1 is arranged. Next, switching from the reflection original to the transparent original is performed by the switching button 5 of the circuit / power supply unit 2. Reading is started in the above state, but the lamp 6 in the circuit / power supply unit 2 in FIG. 1B is turned on by the above-described switch button 5 for the transparent original, and the lamp 8 in the carriage 7 is used. do not do. In addition, the carriage 7 is stopped at the upper part of the window 9 provided in the scanner main body 1 as shown in FIG. 1C, that is, at the position shown in FIG. This is done by reading. Then, the carriage 7 is moved in the direction A, and the transparent original 4 is passed through the lamp 6 and the white panel 3.
Is read.

FIG. 2 shows another embodiment of the present invention. A changeover switch 10 is arranged above the circuit / power supply unit 2 in place of the changeover button 5 in FIG. When reading the transparent original, as described above, when the scanner main body 1 is disposed above the circuit / power supply section 2, the scanner main body 1 presses the changeover switch 10 to automatically switch to the lamp 6 for reading the transparent original, The switching of the reading position is performed.

〔The invention's effect〕

As described above, the present invention uses a lamp in the scanner body and a white reference original in the case of reading a reflection original, and uses an illumination device separately from the scanner main body in the case of reading a transparent original. White panel on the lighting device,
By switching the white reference original and reading it, the optical path appropriate for each of the reflection original and the transmission original is set.
By performing shading correction, color balance adjustment, and sensor output adjustment, more accurate image reading can be realized.

In addition, when reading the original, both the reflective original and the transmissive original have a structure in which the original can be viewed directly, so that the original can be reliably set and read.

In addition, by separating a control circuit and a power supply unit from the scanner main body and integrating them with the illumination device, the scanner main body is reduced in weight and operability is improved. By providing a switch for automatically switching between a reflective original and a transparent original in the illumination / circuit / power supply section, anyone can read an image without failure. Therefore, the present invention makes it possible to easily read a transparent original by applying to a portable image reading apparatus which can read only a reflective original in the past, and there is an immense advantage in the market.

[Brief description of the drawings]

FIG. 1A is an explanatory view showing one embodiment of the present invention, and FIG.
FIG. 3 is a partial cross-sectional view of the image reading device, and FIG. 3C is an explanatory diagram of the scanner body of the image reading device as viewed from a side in contact with a document. FIG. 2 is an explanatory view showing another embodiment of the present invention. FIG. 3A is a cross-sectional view of a carriage in a sub-scanning direction in another conventional image reading apparatus, FIG. 3B is a cross-sectional view of the same in the main scanning direction, and FIG. 3C is a conceptual diagram of the conventional image reading apparatus. is there. FIG. 4 is an explanatory view of the conventional reading apparatus. DESCRIPTION OF SYMBOLS 1 ... Scanner main body 2 ... Circuit and power supply unit 3 ... White panel 4 ... Transparent original 5 ... Switching button 6, 8 ... Lamp 7 ... Carriage 9 ... Window 10 ... Switching switch 11 ... Self-scanning photoelectric converter 12 Lens 13 Reading range 14 Pulse motor 15 Pulley 16 Belt 17 Guide shaft 18 Original plate 19 Original confirmation plate 20 Reflective original 21 …… White reference tape

Claims (5)

(57) [Claims] 1. A reflection type original can be read in a state in which a reflection type original can be directly viewed by moving a reading head having at least an image sensor and a light source between a first transparent plate in contact with the original and a second transparent plate opposite to the first transparent plate. In the image reading apparatus having an original reading means, the illumination means for illuminating the original from the side facing the reading head via the original can read the original in a state in which the transmissive original can be directly viewed. An image reading apparatus, comprising: 2. An image reading apparatus according to claim 1, wherein said illuminating means has a light source and a transparent white diffusion plate. 3. The original reading means can also be used for reflection type original reading separated from the illuminating means, and switching between transmission type original reading and illuminating means reading by a switching means is provided. The image reading device according to claim 1, wherein: 4. The document reading means according to claim 1, wherein the white reference reading prior to the transmission type document reading is performed using a window provided on a surface facing the document. Image reader. 5. A document reading means capable of reading a document in a state where the document can be directly viewed by moving at least a reading head having an image sensor between a first transparent plate in contact with the document and a second transparent plate on the opposite side. And an illuminating means for illuminating the original from the side facing the reading head via the original. An image reading apparatus which can read a transmissive original by including: a surface facing the original. An image reading apparatus provided with a window used for reading based on white color prior to reading of a transmissive original.