阅读说明：本技术 图像形成装置 (Image forming apparatus with a toner supply device ) 是由 谷本弘二 于 2020-02-10 设计创作，主要内容包括：本申请提供防止发光元件的不必要的发光并且原始图像的再现性优异的图像形成装置。实施方式的图像形成装置具备获取部、打印头、处理器以及图像形成部。获取部获取包括多个图像线的图像数据。打印头包括多个驱动电路以及多个发光元件,所述多个驱动电路具有保持根据所述图像数据而变化的电位的电容器,所述多个发光元件根据所述多个驱动电路的各电容器的电位而发光。处理器通过针对所述多个驱动电路的所述图像数据的输出来控制所述多个发光元件的发光,并且在根据所述多个图像线中的最终线来控制所述多个发光元件的发光后,执行针对所述多个发光元件的第一熄灭控制。图像形成部形成与所述多个发光元件的发光相应的图像。(The present application provides an image forming apparatus which prevents unnecessary light emission of a light emitting element and is excellent in reproducibility of an original image. The image forming apparatus according to an embodiment includes an acquisition unit, a print head, a processor, and an image forming unit. The acquisition unit acquires image data including a plurality of image lines. The print head includes a plurality of driving circuits having capacitors holding potentials that vary according to the image data, and a plurality of light emitting elements that emit light according to potentials of the capacitors of the plurality of driving circuits. The processor controls light emission of the plurality of light emitting elements by output of the image data to the plurality of driving circuits, and performs first turn-off control for the plurality of light emitting elements after controlling light emission of the plurality of light emitting elements according to a final line of the plurality of image lines. The image forming unit forms an image corresponding to the light emission of the plurality of light emitting elements.)

1. An image forming apparatus is characterized by comprising:

an acquisition unit that acquires image data including a plurality of image lines;

a print head including a plurality of driving circuits having capacitors that hold potentials that vary according to the image data, and a plurality of light emitting elements that emit light according to potentials of the capacitors of the plurality of driving circuits;

a processor which controls light emission of the plurality of light emitting elements by output of the image data to the plurality of driving circuits, and performs first turn-off control for the plurality of light emitting elements after controlling light emission of the plurality of light emitting elements according to a final line of the plurality of image lines; and

and an image forming unit for forming an image corresponding to the light emission of the plurality of light emitting elements.

2. The image forming apparatus according to claim 1,

the processor performs the first blanking control by outputting a control signal in which white image data is attached to the final line,

the plurality of light emitting elements are turned off according to white image data added based on the control signal.

3. The image forming apparatus according to claim 1,

the image forming apparatus includes a plurality of switches for switching supply or non-supply of current to the plurality of light emitting elements,

the processor performs the first blanking control by outputting a control signal in which white image data is attached to the final line,

the plurality of switches switch the currents to the plurality of light emitting elements to non-supply based on a switching signal output according to the white image data.

4. The image forming apparatus according to claim 1,

the processor performs second turn-off control for the plurality of light-emitting elements before controlling light emission of the plurality of light-emitting elements by output of the image data for the plurality of driving circuits.

5. The image forming apparatus according to claim 1,

the processor executes the first turning-off control when the final line is other than white, and does not execute the first turning-off control when the final line is white.

Technical Field

Embodiments of the present invention relate to an image forming apparatus.

Background

Image forming apparatuses such as printers, copiers, and multifunction peripherals (MFPs) using an electrophotographic program are known. Two types of exposure means (exposure unit) known as laser optical systems (LSU: laser scanning unit) and print heads (solid head) are used as the exposure means (exposure unit) of these image forming apparatuses. In the laser optical system, the photosensitive drum is exposed by the laser light scanned by the polygon mirror. In the print head, the photosensitive drum is exposed to Light output from a plurality of Light Emitting elements such as LEDs (Light Emitting diodes).

Since the polygon mirror needs to be rotated at a high speed, the laser optical system consumes a large amount of energy and generates operating sound when forming an image. Further, since a mechanism for scanning the laser light and a lens group for imaging the scanning light on the photosensitive drum are required, there is a tendency to become a large unit shape.

On the other hand, the print head is configured to form an image of light emitted from the plurality of light emitting elements on the photosensitive drum by using a small lens that links an erect image called a rod lens array, and therefore can be downsized. Further, since the print head has no movable portion, it is a quiet exposure unit with low energy consumption. In addition, in the print head, in addition to the LED (arrayed LED chip), an OLED (Organic Light Emitting Diode) may be developed and used.

A print head using LEDs generally arranges LED chips on a printed substrate. Since Organic EL (Electroluminescence) is collectively formed on a substrate using a mask, the OLED can have light-emitting elements arranged with high accuracy. For example, an example is known in which a plurality of light-emitting elements formed of organic EL are formed on a glass substrate.

A plurality of light emitting elements of the print head correspond to one line in the main scanning direction, and each light emitting element emits light based on the pixel information read out from the page memory. That is, the light emission timing of each light emitting element of the print head is controlled based on the pixel information of the image data.

Disclosure of Invention

The active light emitting element of the print head emits light in accordance with the charge (potential) held by the capacitor, and an image is formed based on the light emission. In the case where light emission of the light emitting element is controlled based on effective image data, there is a possibility that unnecessary light emission is caused due to electric charges held by the capacitor. There is a possibility that the reproducibility of the original image is lowered by unnecessary light emission.

An object of the present invention is to provide an image forming apparatus which prevents unnecessary light emission of a light emitting element and is excellent in reproducibility of an original image.

Drawings

Fig. 1 is a diagram showing an example of a positional relationship between a photosensitive drum and a print head applied to an image forming apparatus according to a first embodiment.

Fig. 2 is a diagram showing an example of a transparent substrate constituting the print head according to the first embodiment.

Fig. 3 is a diagram showing an example of a light-emitting element row (two rows of headers) according to the first embodiment.

Fig. 4 is a diagram illustrating an example of the structure of the light-emitting element according to the first embodiment.

Fig. 5 is a diagram showing an example of a circuit configuration including a DRV circuit for driving the light-emitting element according to the first embodiment and a light-emitting element which emits light by the DRV circuit.

Fig. 6 is a diagram showing an example of a head circuit block of the print head according to the first embodiment.

Fig. 7 is a diagram showing an example of an image forming apparatus to which the print head according to the first embodiment is applied.

Fig. 8 is a block diagram showing an example of a control system of the image forming apparatus according to the first embodiment.

Fig. 9 is a diagram showing an example of image data transfer (including transfer of additional white image data) in the image forming apparatus according to the first embodiment.

Fig. 10 is a diagram showing an example of image data transfer (transfer not including additional white image data) in the image forming apparatus according to the first embodiment.

Fig. 11 is a diagram showing an example of an image formed based on the transmission of the image data shown in fig. 9 (including the transmission of the additional white image data).

Fig. 12 is a diagram showing an example of an image (trailing image) formed based on the transmission of the image data shown in fig. 10 (transmission of the additional white image data is not included).

Fig. 13 is a flowchart showing a first example of the light-off control (non-emission control) performed by the image forming apparatus according to the first embodiment.

Fig. 14 is a flowchart showing a second example of the light-off control (non-emission control) performed by the image forming apparatus according to the first embodiment.

Fig. 15A is a diagram showing an example of the relationship between the sample/hold signal and the light emission state of the light-emitting element when the quenching control according to the first embodiment is applied.

Fig. 15B is a diagram showing an example of the relationship between the sample/hold signal and the light emission state of the light-emitting element when the quenching control according to the first embodiment is applied.

Fig. 16A is a diagram showing an example of the relationship between the sample/hold signal and the light emission state of the light-emitting element when the quenching control is not applied.

Fig. 16B is a diagram showing an example of the relationship between the sample/hold signal and the light emission state of the light-emitting element in the case where the quenching control is not applied.

Fig. 17 is a diagram showing an example of a circuit configuration including a DRV circuit for driving the light-emitting element according to the second embodiment, a light-emitting element which emits light by the DRV circuit, and a switch which switches supply of current to the light-emitting element.

Fig. 18 is a diagram showing an example of a head circuit block of the print head according to the second embodiment.

Fig. 19 is a diagram showing an example of the relationship between the sample/hold signal, the potential of the capacitor, the effective image data D1, and the additional white image data D2, the switch SW, and the light emission state of the light-emitting element when the light-off control according to the second embodiment is applied.

Fig. 20 is a diagram showing an example of the relationship among the sample/hold signal, the potential of the capacitor, the effective image data D1, the switch SW, and the light emission state of the light-emitting element in the case where the light-off control according to the second embodiment is not applied.

Description of the reference numerals

1 … print head; 10 … a light emitting portion; 11 … a transparent substrate; 12 … rod lens array; 13 … light-emitting element row; 100 … image forming apparatus; 111 … photosensitive drum; 131 … light emitting element; 171 … image reading unit; 172 … image processing section; 173 … image forming part; 174 … control section; 179 … control panel; 183 … image data transfer control unit.

The image forming apparatus according to an embodiment includes an acquisition unit, a print head, a processor, and an image forming unit. The acquisition unit acquires image data including a plurality of image lines. The print head includes a plurality of driving circuits having capacitors holding potentials that vary in accordance with the image data and the correction data, and a plurality of light emitting elements that emit light in accordance with potentials of the capacitors of the plurality of driving circuits. The processor controls light emission of the plurality of light emitting elements by output of the image data to the plurality of driving circuits, and after controlling light emission of the plurality of light emitting elements according to a final line of the plurality of image lines, the processor performs first light-off control for the plurality of light emitting elements. The image forming unit forms an image corresponding to the light emission of the plurality of light emitting elements.