JPS61144965A - Image reading device - Google Patents

Abstract

PURPOSE:To perform reading operation when the quantity of light is optimum and perform the reading operation accurately by deciding on the level of an image signal from a reference object. CONSTITUTION:When a readout object 2 is read, a light emitting body 3 is turned on to illuminate the reference object 1. At the point of time, the image signal obtained by an image sensor 5 is supplied to a level decision part 7 to decide on the image signal level, thereby deciding on the range of the quantity of read light, i.e. output light of the light emitting body 3. Then when the quantity of the output light of the light emitting body 3 becomes enough to make a read, the readout object body 2 is read. Consequently, even if the light emitting body varies in the quantity of light when turned on, the readout object 2 is read with the quantity of light suitable for the reading, so the object is read excellently.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an image reading (image reading) device having a light emitter for illuminating a subject, particularly when the amount of light from the light emitter is not determined at a constant pressure due to external factors. The present invention relates to an image reading device that can prevent failures in reading images.

[Background of the invention]

In conventional devices, the light emitting body for illuminating the subject has a temperature of the light emitting body,
Because external fluctuation factors such as the amount of energy applied to the light emitter cause fluctuations in the amount of light output from the light emitter, making it impossible to read high-quality images, we installed a constant temperature device on the light emitter and a constant current device for the light emitter. It was difficult to obtain a stable amount of light, making it impossible to read high-quality images.

[Purpose of the invention]

An object of the present invention is to provide an image reading system that can perform accurate reading with the best light amount even when using a light emitter for illuminating a subject whose light amount fluctuates, and that can use an inexpensive illumination device. The goal is to provide equipment.

[Summary of the invention]

By providing a reference object and determining the level of the image signal from the reference object, the reading operation is performed when the amount of light is good.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Figure 1 shows the overall configuration, and the light emitter 3 is the device control unit 8.
The reference object 1 is illuminated under control. The image light of the reference object 1 passes through the lens 4, is converted into a stain signal by the image sensor 5, is processed by the image signal processing section 6, and is outputted as image information to an external device.

Further, the image signal processing unit 6 is configured to output an image signal to the υ level determination unit 7.

When this apparatus reads the object 2 to be read, first the light emitter 3 is turned on to illuminate the reference object 1. The image signal obtained from the image sensor 5 at this point is given to the level determination section 7 to determine the image signal level, thereby determining the light amount range for reading the output light amount of the light emitter 3. When the output light quantity stabilizes to a sufficient light quantity for reading, the reading object 2 is read. FIG. 2 shows this flowchart. In addition to this, luminous body 3
Even if the amount of light fluctuates when the light is turned on, the object 2 can be read when the amount of light that is suitable for reading is reached, so high-quality reading can be performed.

〔Effect of the invention〕

According to the present invention, even when an image reading device uses a light emitter for illuminating a subject that has variations in light amount, it is possible to perform a reading operation at the best light amount, so that high-quality reading can be performed. , and an inexpensive lighting device can be used.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, and FIG.
3 is a flowchart of the operation shown in FIG.

Claims (1)

[Claims] 1. An illumination light emitter that illuminates the reading subject, an image sensor that converts the optical image from the reading subject into an electrical signal,
In an image reading device having an image signal processing unit that processes electrical signals from an image sensor, a reference subject is provided, and the image signal processing unit determines the level of the electrical signal from the image sensor based on the optical image from the reference subject. An image reading device comprising a level determining means and performing an image reading operation by detecting that the amount of light from a light emitter is within an effective image reading range.